BACKGROUND The rising prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)in neonatal intensive care units(NICUs)represents an escalating challenge in healthcare settings,particularly in managing hospital-...BACKGROUND The rising prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)in neonatal intensive care units(NICUs)represents an escalating challenge in healthcare settings,particularly in managing hospital-acquired infections(HAIs).Studies across various World Health Organization regions have documented a significant incidence of CRAB-related HAIs,with rates as high as 41.7 cases per 1000 patients in ICUs,accounting for 13.6%of all HAIs.These infections pose a doubled mortality risk compared to infections with carbapenem-susceptible Acinetobacter baumannii.A particularly concerning aspect of CRAB colonization is its asymptomatic nature,enabling its transmission through healthcare workers(HCWs)or the NICU environment to vulnerable neonates with developing immune systems.AIM To explore the prevalence of CRAB colonization in NICUs,focusing on neonates,healthcare workers,and the environmental samples,to enhance epidemiological understanding and inform targeted interventions.METHODS We conducted according to PRISMA 2020 checklist guidelines,a comprehensive literature search across multiple databases including MEDLINE(Ovid),EMBASE(Ovid),Global Health(Ovid),Web of Science,and Global Index Me-dicus.Studies were selected based on predetermined criteria,primarily involving neonates,HCWs,and environmental swabs,using culture or molecular methods to detect CRAB colonization.We excluded studies that did not specifically focus on NICUs,were duplicates,or lacked necessary data.The study selection and quality assessment were conducted independently by two reviewers.Data extraction involved collecting comprehensive details about each study.Our statistical analysis used a random-effects model to calculate the pooled prevalence and confidence intervals,stratifying results by regional location.We assessed study heterogeneity using Cochran's Q statistic and I²statistic,with regression tests employed to evaluate potential publication bias.RESULTS We analyzed 737 records from five databases,ultimately including 13 studies from ten countries.For neonates,the pooled prevalence was 4.8%(95%CI:1.1%to 10.5%)with the highest rates observed in South-East Asia(10.5%;95%CI:2.4%to 23.3%).Among HCWs,a single Indian study reported a 3.3%prevalence.Environmental samples showed a prevalence of 2.3%(95%CI:0%to 9.3%),with the highest rates in South-East Asia(10%;95%CI:4.2%to 17.7%).Significant heterogeneity was found across studies,and no publication bias was detected.CONCLUSION This systematic review highlights a significant prevalence of CRAB colonization in neonates across various regions,particularly in South-East Asia,contrasting with lower rates in high-income countries.The study reveals a gap in research on HCWs colonization,with only a single study from India reporting moderate prevalence.Environmental samples indicate moderate levels of CRAB contamination,again higher in South-East Asia.These findings underscore the need for more extensive and focused research on CRAB colonization in NICUs,including exploring the roles of HCWs and the environment in transmission,understanding antimicrobial resistance patterns,and developing effective prevention measures.展开更多
Purpose: In recent years, multidrug-resistant Acinetobacter baumannii has appeared and caused outbreaks of hospital infections all over the world. Close monitoring of this pathogen and other A. baumanii complex specie...Purpose: In recent years, multidrug-resistant Acinetobacter baumannii has appeared and caused outbreaks of hospital infections all over the world. Close monitoring of this pathogen and other A. baumanii complex species is considered of critical importance to public health organizations. The reliable identification method able to distinguish A. baumannii from genetically close Acinetobacter species is needed, because these species are unable to be differentiated by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect A. baumanii complex species, and Acinetobacter lwoffii which is frequently detected from the human specimens, and to investigate the distribution of these organisms in dental hospital using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the 16S ribosomal RNA (16S rRNA) gene and DNA gyrase subunit B (gyrB) of each species of A. baumanii complex species. Swab samples were collected from ten dental spittoon units in dental hospital, and the distribution of A. baumanii complex species was investigated using a multiplex PCR. Results: These primers were able to distinguish each species of A. baumanii complex species clearly. A. baumanii and A. calcoaceticus were detected at 20.0% and 10.0% in ten swab samples, respectively. On the other hand, A. nosocomialis, A. lowffii, and A. pittii were detected from no sample. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and worked without requiring DNA extraction.展开更多
Background: Multi-drug resistant and Carbapenem-Resistant Acinetobacter baumannii (CRAB) infections present a significant challenge in hospital ICU settings worldwide and the threat posed is worse in developing countr...Background: Multi-drug resistant and Carbapenem-Resistant Acinetobacter baumannii (CRAB) infections present a significant challenge in hospital ICU settings worldwide and the threat posed is worse in developing countries including Kenya. Despite the limited treatment options, there is inadequate comprehensive data on factors associated with MDR and CR Acinetobacter baumannii carriage among ICU patients hospitalized at hospitals. This study therefore aimed to address this gap and determined risk factors associated with MDR and CR Acinetobacter baumannii carriage among ICU patients hospitalized at MOI Teaching and Referral Hospital, Kenya. Methods: Through cross-sectional study design, a total of 132 ICU admitted patients were purposively enrolled in this study between July 2019 and July 2020. Demographic and risk factors associated with MDR and CR Acinobacter baumannii were collected using structured questionnaire. Descriptive statistics and bivalent analysis were used for data analysis obtained. Level of statistical significance was 95% confidence interval (CI) for all analysis. Results: Bivariable analysis showed that employed participants were 3.4 times more likely to have A. baumannii compared to the unemployed (cOR = 3.38, 95%, CI: 1.09 - 10.43, p = 0.035). Patients who were having high BMI were likely to be infected by A. baumannii compared to those who had normal/low BMI (aOR = 11.2, 95%, CI: 3.57 - 21.11, p = 0.004). Those who were aged ≥ 50 years were 21 times more likely to be carbapenem-resistant Acinetobacter baumannii, COR = 21.0, 95% CI: 1.83 - 240.52, p = 0.011. Those who stayed in ICU for more than 30 days were 16 times more likely to be carbapenem-resistant Acinetobacter baumannii compared to those who had been admitted (COR = 16.0, 95% CI: 1.45 - 176.45, p = 0.019). Conclusion: Increased length of hospital stay, obesity and marital status were the factors found to be significantly associated with A. baumannii infections among ICU admitted patients. On the other hand, gender, age, level of education, occupation, referral status and presence of infection were found to have no significant association with A. baumannii infections among ICU admitted patients. All patients admitted to the intensive care units should be screened for colonization with A. baumannii, owing to the poor treatment outcomes associated with carriage of this multidrug resistant pathogen. Proper infection control in the ICU settings should be upheld to mitigate the spread of A. baumannii in the intensive care units.展开更多
Objective:To analyze the clinical distribution and drug resistance of Acinetobacter baumannii(AB)and provide reference for the treatment of AB infection.Methods:AB isolated from clinical specimens of Huaihua First Peo...Objective:To analyze the clinical distribution and drug resistance of Acinetobacter baumannii(AB)and provide reference for the treatment of AB infection.Methods:AB isolated from clinical specimens of Huaihua First People’s Hospital from 2019 to 2021 were collected and identified by VITEK 2 Compact,an automated microbial identification and susceptibility testing system,in which drug sensitivity test was also performed.Excel was used for statistical analysis.Results:Among the 1,311 AB strains,81.16%(1,064 strains)were from sputum samples,and the departments with the highest detections rates of AB were neurosurgery(24.33%),intensive care(15.48%)and infectious disease(11.44%).The drug sensitivity test showed that the resistance rate of 1,311 AB strains to compound sulfamethoxazole and amikacin was 28.38%and 20.54%,respectively,and the resistance rate to 10 other kinds of common antibiotics was more than 40%.Conclusion:The 1,311 AB strains isolated were widely distributed in clinical settings and had strong resistance to commonly used antibiotics.Therefore,it is necessary to strengthen the monitoring of pathogens and drug resistance,formulate reasonable and effective infection control measures,and ensure that antibiotics are used in a reasonable manner.展开更多
Background:Intracranial infection after craniotomy is one of the most serious postoperative complications,especially multidrug-resistant(MDR)or extensively drug-resistant(XDR)bacterial meningitis,and strongly affects ...Background:Intracranial infection after craniotomy is one of the most serious postoperative complications,especially multidrug-resistant(MDR)or extensively drug-resistant(XDR)bacterial meningitis,and strongly affects the prognosis of patients.Current treatment experience regarding these infections is scarce.Case presentation:We report a case of severe intracranial infection of XDR Acinetobacter baumannii(A.baumannii)that was treated by intravenous(IV)injection,sequential intraventricular(IVT)injection of tigecycline and polymyxin B,and other anti-infective drugs.Good results were obtained,and the patient was eventually discharged from the hospital.This case is characterized by intracranial infection.Conclusions:The polymyxin B IV+IVT pathway is an ideal treatment strategy for XDR A.baumannii.The tigecycline IVT pathway is also a safe treatment option.展开更多
Herbicidal residues of imazamox are hazardous to some sensitive rotational aftercrops.The aim of the study was to isolate and identify a microbial strain capable of degrading imazamox.The strain IB5,capable of efficie...Herbicidal residues of imazamox are hazardous to some sensitive rotational aftercrops.The aim of the study was to isolate and identify a microbial strain capable of degrading imazamox.The strain IB5,capable of efficiently degrading imazamox,was isolated from an imazamox-contaminated soybean field in Heilongjiang Province,China.It was found to degrade 98.61%of 400 mg L^(-1) imazamox within 48 h by high-performance liquid chromatograph.Through morphological,physiological and biochemical characterization,and the 16 S rDNA sequencing,the strain was identified as Acinetobacter baumannii.An optimal degradation condition was obtained and verified:400 mg L^(-1) imazamox,0.1%(volume ratio) initial inoculum,37℃and pH 7.0.Four main products were captured in the liquid chromatograms and mass spectra,and a pathway for imazamox degradation by IB5 was proposed.This work provides a new suitable candidate for imazamox biodegradation and theoretical evidence for imazamox residue bioremediation.A.baumannii is a common clinical bacteria,but its imazamox-degrading feature has not been reported previously.展开更多
Objective:To investigate the antibiotic resistance genes inserted into class I and class 2integrons in Acinetobacler baumannii[A.baumannii)isolates obtained from nine different cities in Turkey.Methods:A collection of...Objective:To investigate the antibiotic resistance genes inserted into class I and class 2integrons in Acinetobacler baumannii[A.baumannii)isolates obtained from nine different cities in Turkey.Methods:A collection of 281 A.baumannii clinical isolates were collected from nine diferenl state hospitals in Turkey and were confirmed as A.baumannU by conventional biochemical,API testing and bla_(-OXA-51)specific PCR.The isolates were examined by PCR for existence of class I and2 integron gene cassettes.Results:They were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin(90.03%),ciprofloxacin(87.54%),cefepime and trimethoprim/sulfamethoxazole(81.13%).The lowest resistance rates was for cefotaxime(3.55%).class 1 integrons were detected in 6.4%(18/281)of A.baumannii strains and no class 2 integron was detected.The gene casselles of class 1 inlegrons AacCI-AAC(3)l-aadAI,AacCI-aadA1,AAC(3)-I,AAC(3)-I-AAC(3)-I-aadA1,TEM-1.AAC(3)-I-aadA1-AAC(3)-I-AAC(3)-I,AAC(3)-I-AAC(3)-I-AAC(3)-I-aadA1,AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I,AAC(3)-I-aadA1-AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I-aadA1-AAC(3)-I-aadA1 were detected in eighteen strains.The aac genes family were most frequently found integrated into the class 1 inlegrons and it was followed by aadA genes and TEM-1 genes.Conclusions:This is an extensive study on the distribulion of class 1 integron among A.baumannii in Turkey.In addition to these,two new alleles were observed.Their percentage rates of similarity to other cassettes are 95%aadA1(TK A18)and 89%,aadA 1(ANKA3).展开更多
BACKGROUND:The Acinetobacter baumannii group,including Acinetobacter baumannii,Acinetobacter genomospecies 3 and 13 TU,is phenotypically indistinguishable and uniformly identified as Acinetobacter baumannii by laborat...BACKGROUND:The Acinetobacter baumannii group,including Acinetobacter baumannii,Acinetobacter genomospecies 3 and 13 TU,is phenotypically indistinguishable and uniformly identified as Acinetobacter baumannii by laboratories of clinical microbiology.This review aimed to demonstrate the differences among them.METHODS:Literatures associated with the Acinetobacter baumannii group were identified and selected from PubMed databases and relevant journals.RESULTS:Acinetobacter genospecies 3 and 13 TU possess a certain proportion in clinical isolates.There were considerable differences in epidemiologic features,clinical manifestations,antimicrobial resistances and therapeutic options among the Acinetobacter baumannii group.Compared with Acinetobacter genomospecies 3 and 13 TU,Acinetobacter baumannii with a higher resistance to antimicrobial agents are easier to be treated inappropriately,and present a worse outcome in patients.CONCLUSION:The Acinetobacter baumannii group comprises three distinct clinical entities,and their clinical value are not equal.展开更多
BACKGROUND Pyogenic ventriculitis caused by extensively drug-resistant Acinetobacter baumannii(A.baumannii)is one of the most severe complications associated with craniotomy.However,limited therapeutic options exist f...BACKGROUND Pyogenic ventriculitis caused by extensively drug-resistant Acinetobacter baumannii(A.baumannii)is one of the most severe complications associated with craniotomy.However,limited therapeutic options exist for the treatment of A.baumannii ventriculitis due to the poor penetration rate of most antibiotics through the blood-brain barrier.CASE SUMMARY A 68-year-old male patient with severe traumatic brain injury developed pyogenic ventriculitis on postoperative day 24 caused by extensively drug-resistant A.baumannii susceptible to tigecycline only.Successful treatment was accomplished through multi-route administration of tigecycline,including intravenous combined with continuous ventricular irrigation plus intraventricular administration.The pus was cleared on the 3rd day post-irrigation,and cerebrospinal fluid cultures were negative after 12 d.CONCLUSION Our findings suggest that multi-route administration of tigecycline can be a therapeutic option against pyogenic ventriculitis caused by extensively drugresistant A.baumannii.展开更多
Objective: To determine the antibiotic resistance patterns of the Acinetobacter(A.) baumannii complex isolates that cause the confirmed infection. Methods: The present descriptive study was performed from March 2016 t...Objective: To determine the antibiotic resistance patterns of the Acinetobacter(A.) baumannii complex isolates that cause the confirmed infection. Methods: The present descriptive study was performed from March 2016 to March 2018 in three referral hospitals in Isfahan, Iran. All A. baumannii complex strains isolated from different clinical samples were identified by conventional phenotypic methods and antibiotic susceptibility pattern was detected. After the clinical investigation, contaminated samples were excluded and the source(hospital/community) and site of the infection were determined. Data on antibiotic susceptibility testing were extracted from WHONET software and analysis was done with SPSS.Results: From 254 patients who had confirmed A. baumannii complex infection, 158(62.20%) cases were male, 27(10.63%) were less than 20 years old, 172(67.72%) had healthcare-associated infections and 96(37.79%) were admitted in intensive care units. The most frequent infection was bloodstream infections(111, 43.70%). Our results showed that most of the isolates were resistant to most of the antibiotics(more than 75.00%) and a lower rate of non-susceptibility was observed against minocycline(20, 44.44%) and colistin(0%). The rate of multidrug-resistant isolates was 88.97%. There was no significant difference between resistance of A. baumannii complex isolates according to age. However, the resistance to amikacin and minocycline and the rate of multidrug resistance(MDR) were significantly different between males and females. In patients with healthcare associated infection(HAI), MDR isolates were significantly different regarding admission in ICU ward. Resistance to levofloxacin and ciprofloxacin were lower in isolates from patients with bloodstream infections in comparison to other diagnoses.Conclusions: In our study, a high level of antibiotic resistance was detected in both community-acquired and healthcare-associated A. baumannii complex infections. Appropriate antibiotic prescription in a clinical setting is an essential need for the control and prevention of A. baumannii resistant infections.展开更多
BACKGROUND:With beta-lactam drugs and immunosuppressants widely used,the infection caused by Acinetobacter baumannii(Ab) has become more and more serious with multidrug resistant Acinetobacter baumannii(MDRAb) emergin...BACKGROUND:With beta-lactam drugs and immunosuppressants widely used,the infection caused by Acinetobacter baumannii(Ab) has become more and more serious with multidrug resistant Acinetobacter baumannii(MDRAb) emerging and worsening rapidly.Compared with other patients,the incidence and multidrug resistance of MDRAb are higher in children in pediatric intensive care unit(PICU) because of immune deficiency,severe basic diseases,prolonged hospitalization and invasive operations.Hence it is significant to study the epidemiology and changes of antibacterial susceptibility in order to reduce the incidence of MDRAb in children.METHODS:A total 115 patients with MDRAb pneumonia and 45 patients with negative MDRAb(NMDRAb) pneumonia who had been treated from January 2009 to August 2011 were studied retrospectively at the PICU of Wuhan Children's Hospital.Clinical data were analyzed with univariate and multivariate Logistic regression.RESULTS:In 176 clinical strains of Acinetobacter baumannii isolated,there were 128 strains of MDRAb,accounting for 72.73%.Drug susceptibility tests showed that the resistance rates of β-lactam antibiotics were more than 70%except for cefoperazone sulbactam.The rates to carbapenems were higher than 90%.They were significantly higher than those of NMDRAb.Amikacin,levofloxacin,ciprofloxacin and minocycline had the lowest drug-resistance rates(<20%).Multivariate Logistic regression revealed that ICU stay,the time of mechanical ventilation,anemia,hypoproteinemia and the use of carbapenems were independent risk factors for MDRAb pneumonia.CONCLUSIONS:MDRAb is an important opportunistic pathogen to pneumonia in PICU,and its drug-resistance is severe.It increases significantly the mortality of patients.It is important to take the effective prevention measures for controlling it.展开更多
BACKGROUND Multidrug-resistant Acinetobacter baumannii(MDRAB) has emerged as an increasingly important pathogen that causes nosocomial meningitis. However,MDRAB-associated nosocomial meningitis is rarely reported in c...BACKGROUND Multidrug-resistant Acinetobacter baumannii(MDRAB) has emerged as an increasingly important pathogen that causes nosocomial meningitis. However,MDRAB-associated nosocomial meningitis is rarely reported in children.CASE SUMMARY We report the case of a 1-year-old girl with a choroid plexus papilloma, who developed postoperative nosocomial meningitis due to MDRAB. The bacterial strain was sensitive only to tigecycline and colistin, and showed varying degrees of resistance to penicillin, amikacin, ceftriaxone, cefixime, cefotaxime,ciprofloxacin, levofloxacin, gentamicin, meropenem, imipenem, and tobramycin.She was cured with intravenous doxycycline and intraventricular gentamicin treatment.CONCLUSION Doxycycline and gentamicin were shown to be effective and safe in the treatment of a pediatric case of MDRAB meningitis.展开更多
To identify risk factors for A. baumannii infection in patients hospitalized in an Intensive Care Unit (ICU) of a tertiary public hospital in Paraná, Brazil, a retrospective paired case-control study (ratio 1:2) ...To identify risk factors for A. baumannii infection in patients hospitalized in an Intensive Care Unit (ICU) of a tertiary public hospital in Paraná, Brazil, a retrospective paired case-control study (ratio 1:2) was conducted from January 2018 to December 2020. Patients in the case group were hospitalized in the ICU with A. baumanni (n = 68 cases) and were compared with patients in the control group, without infection by A. baumannii (n = 136). Both were matched by age (±10 years), sex, and ICU stay (±5 days). Conditional multiple logistic regression was used to determine statistically significant risk factors based on the results of bivariate analyses. Mortality was higher in infected (cases) than in non-infected patients (51.5% vs. 39.7%). The incidence and bacterial resistance increased annually. At bivariate analysis, cases had longer hospital stays (median 35 vs. 22 days, p A. baumannii and antimicrobial resistance. There is need for surveillance, and constant evaluation of control actions. Risk factors were colonization, previous hospitalization, and hospitalization time. This is essential for the decision-making of professionals and optimization of prevention, control, and therapeutic management actions.展开更多
Background: The emergence of carbapenemase producing Acinetobacter baumannii is increasingly reported nowadays and constitutes a major problem to the intensive care unit (ICU) patients with notable extensive-drug resi...Background: The emergence of carbapenemase producing Acinetobacter baumannii is increasingly reported nowadays and constitutes a major problem to the intensive care unit (ICU) patients with notable extensive-drug resistance ability. The study investigates carbapenemase producing A. baumannii strains exhibiting an extensively drug-resistant (XDR) phenotype, isolated from ICU patients in Khartoum. Methods: A total of 100 nonduplicate Gram-negative coccobacilli strains were obtained from microbiology laboratory of ICU patients’ clinical isolates. Molecular identification of A. baumannii was performed by targeting 16S rRNA gene using specifically designed primers. Then, XDR strains were determined by susceptibility testing (disc diffusion). For detection of carbapenemase genes Polymerase chain reaction (PCR) was carried out. Result: Of 100 ICU clinical isolates, 38 (38.0%) was confirmed A. baumannii strains, those strains showed 100% carbapenem resistance and 60.5% extensive drug resistance to the antibiotics tested. The frequency of carbapenemase producer was 57.9% (22/38) of carbapenem resistance A. baumannii (CRAB). The most common carbapenemase associated with resistance was blaOXA gene followed by blaNDM and blaGES A. baumannii isolates. The co-occurrence of blaOXA-48-like and blaNDM, blaOXA-23-like and blaOXA-51, and blaNDM-1 and blaOXA-51 was detected in 22.7%, 18.2% strains and 4.5% respectively. A unique characteristic of our findings was the coharbouring of the genes blaNDM-1, blaOXA-23-like, blaOXA-51 and blaOXA-143 in 9.1% strains (2/22), and this was the first report in the Khartoum city, Sudan. Conclusion: We have demonstrated for the first time a high prevalence of XDR-carbapenemase producing A. baumannii clinical isolates from ICU patients in Khartoum. Also an emergent blaOXA-143 was reported as High-Risk Clones. This highlights the routine mentoring of XDR-carbapenemase producing A. baumannii to avoid clone dissemination in our region hospitals.展开更多
Objective: To study the minimum inhibitory concentration(MIC) of sulbactam against carbapenem-resistant Acinetobacter baumannii(CR-AB) and to determine the dosage regimens reaching target time of free drug concentrati...Objective: To study the minimum inhibitory concentration(MIC) of sulbactam against carbapenem-resistant Acinetobacter baumannii(CR-AB) and to determine the dosage regimens reaching target time of free drug concentration remaining above the MIC(f T>MIC). Methods: Clinical isolates of CR-AB from patients admitted to Phramongkutklao Hospital, Thailand from January 2014 to December 2015 were obtained. The MIC of sulbactam for each CR-AB isolate was determined using the agar dilution method. Each sulbactam regimen was simulated using the Monte Carlo technique to calculate the probability of target attainment(PTA) and the cumulative fraction of response(CFR) in critically ill patients. PTA was defined by how likely a specific drug dose was to reach 40% and 60% f T>MIC. The CFR was the probability of drug dose covering the MIC range of CR-AB. Dosing regimens reaching above 80% of PTA and CFR, were considered as the optimal dosage for documented and empirical therapy, respectively. Results: A total of 118 CR-AB isolates were included in the study. The percentile at the fiftieth and ninetieth MIC of sulbactam were 64 and 192 μg/m L, respectively. For a MIC of sulbactam of 4 μg/m L, all dosage regimens achieved PTA target. However, only a sulbactam dosage of 12 g intravenous daily using 2-4 h infusion or continuous infusion that covered for isolates with a sulbactam MIC of 96 μg/m L, met the PTA or CFR targets. Conclusions: The MIC of sulbactam against CR-AB is quite high. The sulbactam dose of 12 g/day using prolonged infusion was required to achieve the target f T>MIC for CR-AB treatment.展开更多
Objective: The objective is to explore the mechanism of inhibitory effect of three main SCFAs (acetate, propionate and butyrate) on inflammatory response of A549 cells. Methods: Human lung adenocarcinoma cells (A549 c...Objective: The objective is to explore the mechanism of inhibitory effect of three main SCFAs (acetate, propionate and butyrate) on inflammatory response of A549 cells. Methods: Human lung adenocarcinoma cells (A549 cells) were cultured, and were divided into normal control group (NC group), A. baumannii infection group (A. baumannii group), NF-κB inhibitor group (JSH group), A. baumannii infection + sodium acetate group (NaAc group), A. baumannii infection + sodium propionate group (NaPc group) and A. baumannii infection + sodium butyrate group (NaB group). Real-time quantitative PCR was used to detect the mRNA expression of NLRP3, Caspase-1, IL-1β, IL-6, and TGF-β in A549 cells. Western blotting assay was used to determine the expression of autophagy and “pyroptosis” related proteins of NRLP3, cleaved-Caspase-1 (P20), GSDMD (P30), LC-3 and Beclin-1. At the same time, the expression of NF-κB p65 protein in nucleus and cytoplasm of A549 cells was detected. The level of reactive oxygen species in A549 cells was detected by flow cytometry. Results: Compared with A. baumannii group, the mRNA expression of NLRP3, IL-1β and IL-6 in NaAc group, NaPc group and NaB group decreased significantly, the mRNA expression of Caspase-1 in NaPc group and NaB group decreased significantly, only the mRNA expression of TGF-β in NaB group increased significantly;LC3-II expression increased significantly in NaPc group and NaB group, only Beclin-1 expression increased and GSDMD (p30) expression decreased significantly in NaB group. All three kinds of SCFAs could significantly inhibit the expression of cleaved-Caspase-1 (p20) after A. baumannii infection, but there was no significant change in the protein expression of NLRP3. Compared with NC group, the production of reactive oxygen species in A. baumannii group increased significantly at 3 h after A. baumannii infection. Compared with A. baumannii group, NaB could significantly suppress the production of reactive oxygen species induced by A. baumannii. Compared with A. baumannii group, the expression of NF-κB p65 in nucleus was significantly decreased and the expression of NF-κB p65 in cytoplasm was significantly increased after 24 h pre-incubation with NaB, NaPc and NaAc, respectively. Conclusion: A. baumannii can induce inflammatory injury of pulmonary epithelial cells, and the three major SCFAs can inhibit the activation of NLRP3 inflammasome and the release of pro-inflammatory factors through NF-κB/ROS/NLRP3 pathway, which provides a new way for clinical prevention of severe inflammatory injury caused by A. baumannii infection.展开更多
Acinetobacter baumannii is one of the most prevalent pathogens in nosocomial infections and has been cause of concern in recent years because, it has presented multiresistance to antibiotics and besides can form biofi...Acinetobacter baumannii is one of the most prevalent pathogens in nosocomial infections and has been cause of concern in recent years because, it has presented multiresistance to antibiotics and besides can form biofilms on biotic and abiotic surfaces like tissues and medical devices. Therefore, the search for new alternatives of natural origin to inhibit biofilm formation is being conducted. In the present investigation, sub-lethal concentrations (5.61 mg/mL, 3.74 mg/mL and 1.87 mg/mL) of methanolic extract of Nothoscordum bivalve were evaluated, showing biofilm formation inhibition up to 40.8%, in one nosocomial isolated of A. baumannii by the microtiter biofilm formation assay using crystal violet. On the other hand, the concentrations of 5.61 mg/mL and 3.74 mg/mL, caused an overexpression (up to 15.4 times) in the genes involved in the formation of biofilm (abaI, bap and csuE);due to this, the interaction of the extract with the bacteria was analyzed by scanning electron microscopy (SEM) and cellular damage was observed in the structure and stability of biofilm.展开更多
Emerging and rapidly spreading multidrug resistant bacteria constitute a rising public health concern worldwide. Acinetobacter baumannii is one of these bacteria that cause different infections including pneumonia, ba...Emerging and rapidly spreading multidrug resistant bacteria constitute a rising public health concern worldwide. Acinetobacter baumannii is one of these bacteria that cause different infections including pneumonia, bacteremia, meningitis, soft-tissue, and urinary tract infections, and are associated with high mortality and economic burden. We present a case of a 43-year-old woman, admitted at the department of orthopedics, regional hospital of Ourossogui, North-East of Senegal for soft-tissue injuries. Initially diagnosed with Yersinia pestis infection, the patient was well managed before being released. Supplementary sampling for confirmatory tests allowed the detection of an extensively drug-resistant Acinetobacter baumannii clone.展开更多
Model Study: The genus Acinetobacter is composed of opportunistic pathogens that mainly affects immunocompromised and patients during a prolonged hospitalization period. A. baumannii can survive in the hospital settin...Model Study: The genus Acinetobacter is composed of opportunistic pathogens that mainly affects immunocompromised and patients during a prolonged hospitalization period. A. baumannii can survive in the hospital setting at various locations such as mechanical ventilators, dialysis machines, ventilation systems, water sources, skin and mucous membranes of health professionals and patients, drug preparations and disinfectants among others. Antimicrobials are essential for the treatment of infections, so their use has become common, and often inappropriate and abusive. This pathogen has presented multi-resistance to several classes of antimicrobials and has become a major cause of death in hospitals. Objective: To evaluate the occurrence of Acinetobacter baumannii in clinical samples from the Laboratory of Clinical Analyzes, HCSL of Pouso Alegre, MG. Methods: All the samples referring to the patients of the Samuel Libanio Clinical Hospital including most of the specialties were evaluated. From the positive samples for Acinetobacter baumannii the medical records of hospitalized patients were evaluated. From the medical records, data were obtained as gender and age of the patient, place of hospitalization, together with month and year of the laboratory procedure. Result: A total of 14,859 samples of diverse materials were evaluated, being 80 (0.5%) samples positive for Acinetobacter baumannii. Of these positive samples, the largest occurrences were identified in male patients 59 (73.7%), aged over 60 years 37 (46.3%). The most affected hospital sector was Adult ICU with 44 (55.0%) of the cases. In May 2015, there were 5 (6.3%) cases registered and in May 2016, 16 (20.0%) cases. The clinical material with the highest occurrence of Acinetobacter baumannii was Mini Bal 29 (36.3%). Conclusion: Acinetobacter baumannii has been presenting a major increase in clinical samples from the lungs, mainly from male, elderly patients hospitalized in an intensive care unit and with resistance to Polimixin.展开更多
At present,the multiple drug resistance of Acinetobacter baumannii outbreaks worldwide and has intensified the trend,especially in the intensive care unit and burn ward.Generic drug resistant Acinetobacter baumannii i...At present,the multiple drug resistance of Acinetobacter baumannii outbreaks worldwide and has intensified the trend,especially in the intensive care unit and burn ward.Generic drug resistant Acinetobacter baumannii is known as the 21st century gram-negative bacterium“MRSA”,“Superbugs”.In recent years,researches have shown that this is associated with pathogenic bacteria to form biofilms.In this paper,the status of Acinetobacter baumannii infection,biofilm formation,resistance mechanism and prevention in recent years were summarized.展开更多
文摘BACKGROUND The rising prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)in neonatal intensive care units(NICUs)represents an escalating challenge in healthcare settings,particularly in managing hospital-acquired infections(HAIs).Studies across various World Health Organization regions have documented a significant incidence of CRAB-related HAIs,with rates as high as 41.7 cases per 1000 patients in ICUs,accounting for 13.6%of all HAIs.These infections pose a doubled mortality risk compared to infections with carbapenem-susceptible Acinetobacter baumannii.A particularly concerning aspect of CRAB colonization is its asymptomatic nature,enabling its transmission through healthcare workers(HCWs)or the NICU environment to vulnerable neonates with developing immune systems.AIM To explore the prevalence of CRAB colonization in NICUs,focusing on neonates,healthcare workers,and the environmental samples,to enhance epidemiological understanding and inform targeted interventions.METHODS We conducted according to PRISMA 2020 checklist guidelines,a comprehensive literature search across multiple databases including MEDLINE(Ovid),EMBASE(Ovid),Global Health(Ovid),Web of Science,and Global Index Me-dicus.Studies were selected based on predetermined criteria,primarily involving neonates,HCWs,and environmental swabs,using culture or molecular methods to detect CRAB colonization.We excluded studies that did not specifically focus on NICUs,were duplicates,or lacked necessary data.The study selection and quality assessment were conducted independently by two reviewers.Data extraction involved collecting comprehensive details about each study.Our statistical analysis used a random-effects model to calculate the pooled prevalence and confidence intervals,stratifying results by regional location.We assessed study heterogeneity using Cochran's Q statistic and I²statistic,with regression tests employed to evaluate potential publication bias.RESULTS We analyzed 737 records from five databases,ultimately including 13 studies from ten countries.For neonates,the pooled prevalence was 4.8%(95%CI:1.1%to 10.5%)with the highest rates observed in South-East Asia(10.5%;95%CI:2.4%to 23.3%).Among HCWs,a single Indian study reported a 3.3%prevalence.Environmental samples showed a prevalence of 2.3%(95%CI:0%to 9.3%),with the highest rates in South-East Asia(10%;95%CI:4.2%to 17.7%).Significant heterogeneity was found across studies,and no publication bias was detected.CONCLUSION This systematic review highlights a significant prevalence of CRAB colonization in neonates across various regions,particularly in South-East Asia,contrasting with lower rates in high-income countries.The study reveals a gap in research on HCWs colonization,with only a single study from India reporting moderate prevalence.Environmental samples indicate moderate levels of CRAB contamination,again higher in South-East Asia.These findings underscore the need for more extensive and focused research on CRAB colonization in NICUs,including exploring the roles of HCWs and the environment in transmission,understanding antimicrobial resistance patterns,and developing effective prevention measures.
文摘Purpose: In recent years, multidrug-resistant Acinetobacter baumannii has appeared and caused outbreaks of hospital infections all over the world. Close monitoring of this pathogen and other A. baumanii complex species is considered of critical importance to public health organizations. The reliable identification method able to distinguish A. baumannii from genetically close Acinetobacter species is needed, because these species are unable to be differentiated by phenotypic or biochemical methods. The purpose of the present study was to design species-specific primers in order to identify and detect A. baumanii complex species, and Acinetobacter lwoffii which is frequently detected from the human specimens, and to investigate the distribution of these organisms in dental hospital using a multiplex PCR. Methods: Polymerase chain reaction (PCR) primers were designed based on partial sequences of the 16S ribosomal RNA (16S rRNA) gene and DNA gyrase subunit B (gyrB) of each species of A. baumanii complex species. Swab samples were collected from ten dental spittoon units in dental hospital, and the distribution of A. baumanii complex species was investigated using a multiplex PCR. Results: These primers were able to distinguish each species of A. baumanii complex species clearly. A. baumanii and A. calcoaceticus were detected at 20.0% and 10.0% in ten swab samples, respectively. On the other hand, A. nosocomialis, A. lowffii, and A. pittii were detected from no sample. Conclusion: Our developed one-step multiplex PCR method is accurate, specific, cost-effective, time-saving, and worked without requiring DNA extraction.
文摘Background: Multi-drug resistant and Carbapenem-Resistant Acinetobacter baumannii (CRAB) infections present a significant challenge in hospital ICU settings worldwide and the threat posed is worse in developing countries including Kenya. Despite the limited treatment options, there is inadequate comprehensive data on factors associated with MDR and CR Acinetobacter baumannii carriage among ICU patients hospitalized at hospitals. This study therefore aimed to address this gap and determined risk factors associated with MDR and CR Acinetobacter baumannii carriage among ICU patients hospitalized at MOI Teaching and Referral Hospital, Kenya. Methods: Through cross-sectional study design, a total of 132 ICU admitted patients were purposively enrolled in this study between July 2019 and July 2020. Demographic and risk factors associated with MDR and CR Acinobacter baumannii were collected using structured questionnaire. Descriptive statistics and bivalent analysis were used for data analysis obtained. Level of statistical significance was 95% confidence interval (CI) for all analysis. Results: Bivariable analysis showed that employed participants were 3.4 times more likely to have A. baumannii compared to the unemployed (cOR = 3.38, 95%, CI: 1.09 - 10.43, p = 0.035). Patients who were having high BMI were likely to be infected by A. baumannii compared to those who had normal/low BMI (aOR = 11.2, 95%, CI: 3.57 - 21.11, p = 0.004). Those who were aged ≥ 50 years were 21 times more likely to be carbapenem-resistant Acinetobacter baumannii, COR = 21.0, 95% CI: 1.83 - 240.52, p = 0.011. Those who stayed in ICU for more than 30 days were 16 times more likely to be carbapenem-resistant Acinetobacter baumannii compared to those who had been admitted (COR = 16.0, 95% CI: 1.45 - 176.45, p = 0.019). Conclusion: Increased length of hospital stay, obesity and marital status were the factors found to be significantly associated with A. baumannii infections among ICU admitted patients. On the other hand, gender, age, level of education, occupation, referral status and presence of infection were found to have no significant association with A. baumannii infections among ICU admitted patients. All patients admitted to the intensive care units should be screened for colonization with A. baumannii, owing to the poor treatment outcomes associated with carriage of this multidrug resistant pathogen. Proper infection control in the ICU settings should be upheld to mitigate the spread of A. baumannii in the intensive care units.
基金the Scientific Research Project of Hunan Provincial Department of Education(19C1328)the Research-Based Learning and Innovative Experimental Program for College Students in Hunan Province(S202012214040).
文摘Objective:To analyze the clinical distribution and drug resistance of Acinetobacter baumannii(AB)and provide reference for the treatment of AB infection.Methods:AB isolated from clinical specimens of Huaihua First People’s Hospital from 2019 to 2021 were collected and identified by VITEK 2 Compact,an automated microbial identification and susceptibility testing system,in which drug sensitivity test was also performed.Excel was used for statistical analysis.Results:Among the 1,311 AB strains,81.16%(1,064 strains)were from sputum samples,and the departments with the highest detections rates of AB were neurosurgery(24.33%),intensive care(15.48%)and infectious disease(11.44%).The drug sensitivity test showed that the resistance rate of 1,311 AB strains to compound sulfamethoxazole and amikacin was 28.38%and 20.54%,respectively,and the resistance rate to 10 other kinds of common antibiotics was more than 40%.Conclusion:The 1,311 AB strains isolated were widely distributed in clinical settings and had strong resistance to commonly used antibiotics.Therefore,it is necessary to strengthen the monitoring of pathogens and drug resistance,formulate reasonable and effective infection control measures,and ensure that antibiotics are used in a reasonable manner.
基金supported by grants from the National Natural Science Foundation of China(81571940,81741125)the Guangzhou Science and Technology Planning Project of China(201504281714528)PLA Logistics Research Project of China(CWH17L020,17CXZ008,18CXZ030)
文摘Background:Intracranial infection after craniotomy is one of the most serious postoperative complications,especially multidrug-resistant(MDR)or extensively drug-resistant(XDR)bacterial meningitis,and strongly affects the prognosis of patients.Current treatment experience regarding these infections is scarce.Case presentation:We report a case of severe intracranial infection of XDR Acinetobacter baumannii(A.baumannii)that was treated by intravenous(IV)injection,sequential intraventricular(IVT)injection of tigecycline and polymyxin B,and other anti-infective drugs.Good results were obtained,and the patient was eventually discharged from the hospital.This case is characterized by intracranial infection.Conclusions:The polymyxin B IV+IVT pathway is an ideal treatment strategy for XDR A.baumannii.The tigecycline IVT pathway is also a safe treatment option.
基金supported by the Public Welfare Industry Research Project, Ministry of Agriculture of China (201203098)the Harbin Applied Technology Research and Development Project, China (Youth Reserve Talents Class A: 2015RAQYJ009)
文摘Herbicidal residues of imazamox are hazardous to some sensitive rotational aftercrops.The aim of the study was to isolate and identify a microbial strain capable of degrading imazamox.The strain IB5,capable of efficiently degrading imazamox,was isolated from an imazamox-contaminated soybean field in Heilongjiang Province,China.It was found to degrade 98.61%of 400 mg L^(-1) imazamox within 48 h by high-performance liquid chromatograph.Through morphological,physiological and biochemical characterization,and the 16 S rDNA sequencing,the strain was identified as Acinetobacter baumannii.An optimal degradation condition was obtained and verified:400 mg L^(-1) imazamox,0.1%(volume ratio) initial inoculum,37℃and pH 7.0.Four main products were captured in the liquid chromatograms and mass spectra,and a pathway for imazamox degradation by IB5 was proposed.This work provides a new suitable candidate for imazamox biodegradation and theoretical evidence for imazamox residue bioremediation.A.baumannii is a common clinical bacteria,but its imazamox-degrading feature has not been reported previously.
基金Supported by Recep Tayyip Erdogan University(Grant No.BAP2012.102.03.4.and BAP-2013.102.03.4)
文摘Objective:To investigate the antibiotic resistance genes inserted into class I and class 2integrons in Acinetobacler baumannii[A.baumannii)isolates obtained from nine different cities in Turkey.Methods:A collection of 281 A.baumannii clinical isolates were collected from nine diferenl state hospitals in Turkey and were confirmed as A.baumannU by conventional biochemical,API testing and bla_(-OXA-51)specific PCR.The isolates were examined by PCR for existence of class I and2 integron gene cassettes.Results:They were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin(90.03%),ciprofloxacin(87.54%),cefepime and trimethoprim/sulfamethoxazole(81.13%).The lowest resistance rates was for cefotaxime(3.55%).class 1 integrons were detected in 6.4%(18/281)of A.baumannii strains and no class 2 integron was detected.The gene casselles of class 1 inlegrons AacCI-AAC(3)l-aadAI,AacCI-aadA1,AAC(3)-I,AAC(3)-I-AAC(3)-I-aadA1,TEM-1.AAC(3)-I-aadA1-AAC(3)-I-AAC(3)-I,AAC(3)-I-AAC(3)-I-AAC(3)-I-aadA1,AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I,AAC(3)-I-aadA1-AAC(3)-I-aadA1,AAC(3)-I-AAC(3)-I-aadA1-AAC(3)-I-aadA1 were detected in eighteen strains.The aac genes family were most frequently found integrated into the class 1 inlegrons and it was followed by aadA genes and TEM-1 genes.Conclusions:This is an extensive study on the distribulion of class 1 integron among A.baumannii in Turkey.In addition to these,two new alleles were observed.Their percentage rates of similarity to other cassettes are 95%aadA1(TK A18)and 89%,aadA 1(ANKA3).
基金supported by a from grant Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘BACKGROUND:The Acinetobacter baumannii group,including Acinetobacter baumannii,Acinetobacter genomospecies 3 and 13 TU,is phenotypically indistinguishable and uniformly identified as Acinetobacter baumannii by laboratories of clinical microbiology.This review aimed to demonstrate the differences among them.METHODS:Literatures associated with the Acinetobacter baumannii group were identified and selected from PubMed databases and relevant journals.RESULTS:Acinetobacter genospecies 3 and 13 TU possess a certain proportion in clinical isolates.There were considerable differences in epidemiologic features,clinical manifestations,antimicrobial resistances and therapeutic options among the Acinetobacter baumannii group.Compared with Acinetobacter genomospecies 3 and 13 TU,Acinetobacter baumannii with a higher resistance to antimicrobial agents are easier to be treated inappropriately,and present a worse outcome in patients.CONCLUSION:The Acinetobacter baumannii group comprises three distinct clinical entities,and their clinical value are not equal.
文摘BACKGROUND Pyogenic ventriculitis caused by extensively drug-resistant Acinetobacter baumannii(A.baumannii)is one of the most severe complications associated with craniotomy.However,limited therapeutic options exist for the treatment of A.baumannii ventriculitis due to the poor penetration rate of most antibiotics through the blood-brain barrier.CASE SUMMARY A 68-year-old male patient with severe traumatic brain injury developed pyogenic ventriculitis on postoperative day 24 caused by extensively drug-resistant A.baumannii susceptible to tigecycline only.Successful treatment was accomplished through multi-route administration of tigecycline,including intravenous combined with continuous ventricular irrigation plus intraventricular administration.The pus was cleared on the 3rd day post-irrigation,and cerebrospinal fluid cultures were negative after 12 d.CONCLUSION Our findings suggest that multi-route administration of tigecycline can be a therapeutic option against pyogenic ventriculitis caused by extensively drugresistant A.baumannii.
文摘Objective: To determine the antibiotic resistance patterns of the Acinetobacter(A.) baumannii complex isolates that cause the confirmed infection. Methods: The present descriptive study was performed from March 2016 to March 2018 in three referral hospitals in Isfahan, Iran. All A. baumannii complex strains isolated from different clinical samples were identified by conventional phenotypic methods and antibiotic susceptibility pattern was detected. After the clinical investigation, contaminated samples were excluded and the source(hospital/community) and site of the infection were determined. Data on antibiotic susceptibility testing were extracted from WHONET software and analysis was done with SPSS.Results: From 254 patients who had confirmed A. baumannii complex infection, 158(62.20%) cases were male, 27(10.63%) were less than 20 years old, 172(67.72%) had healthcare-associated infections and 96(37.79%) were admitted in intensive care units. The most frequent infection was bloodstream infections(111, 43.70%). Our results showed that most of the isolates were resistant to most of the antibiotics(more than 75.00%) and a lower rate of non-susceptibility was observed against minocycline(20, 44.44%) and colistin(0%). The rate of multidrug-resistant isolates was 88.97%. There was no significant difference between resistance of A. baumannii complex isolates according to age. However, the resistance to amikacin and minocycline and the rate of multidrug resistance(MDR) were significantly different between males and females. In patients with healthcare associated infection(HAI), MDR isolates were significantly different regarding admission in ICU ward. Resistance to levofloxacin and ciprofloxacin were lower in isolates from patients with bloodstream infections in comparison to other diagnoses.Conclusions: In our study, a high level of antibiotic resistance was detected in both community-acquired and healthcare-associated A. baumannii complex infections. Appropriate antibiotic prescription in a clinical setting is an essential need for the control and prevention of A. baumannii resistant infections.
文摘BACKGROUND:With beta-lactam drugs and immunosuppressants widely used,the infection caused by Acinetobacter baumannii(Ab) has become more and more serious with multidrug resistant Acinetobacter baumannii(MDRAb) emerging and worsening rapidly.Compared with other patients,the incidence and multidrug resistance of MDRAb are higher in children in pediatric intensive care unit(PICU) because of immune deficiency,severe basic diseases,prolonged hospitalization and invasive operations.Hence it is significant to study the epidemiology and changes of antibacterial susceptibility in order to reduce the incidence of MDRAb in children.METHODS:A total 115 patients with MDRAb pneumonia and 45 patients with negative MDRAb(NMDRAb) pneumonia who had been treated from January 2009 to August 2011 were studied retrospectively at the PICU of Wuhan Children's Hospital.Clinical data were analyzed with univariate and multivariate Logistic regression.RESULTS:In 176 clinical strains of Acinetobacter baumannii isolated,there were 128 strains of MDRAb,accounting for 72.73%.Drug susceptibility tests showed that the resistance rates of β-lactam antibiotics were more than 70%except for cefoperazone sulbactam.The rates to carbapenems were higher than 90%.They were significantly higher than those of NMDRAb.Amikacin,levofloxacin,ciprofloxacin and minocycline had the lowest drug-resistance rates(<20%).Multivariate Logistic regression revealed that ICU stay,the time of mechanical ventilation,anemia,hypoproteinemia and the use of carbapenems were independent risk factors for MDRAb pneumonia.CONCLUSIONS:MDRAb is an important opportunistic pathogen to pneumonia in PICU,and its drug-resistance is severe.It increases significantly the mortality of patients.It is important to take the effective prevention measures for controlling it.
基金Supported by The Shanghai Pujiang Program,No.12PJ1401500
文摘BACKGROUND Multidrug-resistant Acinetobacter baumannii(MDRAB) has emerged as an increasingly important pathogen that causes nosocomial meningitis. However,MDRAB-associated nosocomial meningitis is rarely reported in children.CASE SUMMARY We report the case of a 1-year-old girl with a choroid plexus papilloma, who developed postoperative nosocomial meningitis due to MDRAB. The bacterial strain was sensitive only to tigecycline and colistin, and showed varying degrees of resistance to penicillin, amikacin, ceftriaxone, cefixime, cefotaxime,ciprofloxacin, levofloxacin, gentamicin, meropenem, imipenem, and tobramycin.She was cured with intravenous doxycycline and intraventricular gentamicin treatment.CONCLUSION Doxycycline and gentamicin were shown to be effective and safe in the treatment of a pediatric case of MDRAB meningitis.
文摘To identify risk factors for A. baumannii infection in patients hospitalized in an Intensive Care Unit (ICU) of a tertiary public hospital in Paraná, Brazil, a retrospective paired case-control study (ratio 1:2) was conducted from January 2018 to December 2020. Patients in the case group were hospitalized in the ICU with A. baumanni (n = 68 cases) and were compared with patients in the control group, without infection by A. baumannii (n = 136). Both were matched by age (±10 years), sex, and ICU stay (±5 days). Conditional multiple logistic regression was used to determine statistically significant risk factors based on the results of bivariate analyses. Mortality was higher in infected (cases) than in non-infected patients (51.5% vs. 39.7%). The incidence and bacterial resistance increased annually. At bivariate analysis, cases had longer hospital stays (median 35 vs. 22 days, p A. baumannii and antimicrobial resistance. There is need for surveillance, and constant evaluation of control actions. Risk factors were colonization, previous hospitalization, and hospitalization time. This is essential for the decision-making of professionals and optimization of prevention, control, and therapeutic management actions.
文摘Background: The emergence of carbapenemase producing Acinetobacter baumannii is increasingly reported nowadays and constitutes a major problem to the intensive care unit (ICU) patients with notable extensive-drug resistance ability. The study investigates carbapenemase producing A. baumannii strains exhibiting an extensively drug-resistant (XDR) phenotype, isolated from ICU patients in Khartoum. Methods: A total of 100 nonduplicate Gram-negative coccobacilli strains were obtained from microbiology laboratory of ICU patients’ clinical isolates. Molecular identification of A. baumannii was performed by targeting 16S rRNA gene using specifically designed primers. Then, XDR strains were determined by susceptibility testing (disc diffusion). For detection of carbapenemase genes Polymerase chain reaction (PCR) was carried out. Result: Of 100 ICU clinical isolates, 38 (38.0%) was confirmed A. baumannii strains, those strains showed 100% carbapenem resistance and 60.5% extensive drug resistance to the antibiotics tested. The frequency of carbapenemase producer was 57.9% (22/38) of carbapenem resistance A. baumannii (CRAB). The most common carbapenemase associated with resistance was blaOXA gene followed by blaNDM and blaGES A. baumannii isolates. The co-occurrence of blaOXA-48-like and blaNDM, blaOXA-23-like and blaOXA-51, and blaNDM-1 and blaOXA-51 was detected in 22.7%, 18.2% strains and 4.5% respectively. A unique characteristic of our findings was the coharbouring of the genes blaNDM-1, blaOXA-23-like, blaOXA-51 and blaOXA-143 in 9.1% strains (2/22), and this was the first report in the Khartoum city, Sudan. Conclusion: We have demonstrated for the first time a high prevalence of XDR-carbapenemase producing A. baumannii clinical isolates from ICU patients in Khartoum. Also an emergent blaOXA-143 was reported as High-Risk Clones. This highlights the routine mentoring of XDR-carbapenemase producing A. baumannii to avoid clone dissemination in our region hospitals.
文摘Objective: To study the minimum inhibitory concentration(MIC) of sulbactam against carbapenem-resistant Acinetobacter baumannii(CR-AB) and to determine the dosage regimens reaching target time of free drug concentration remaining above the MIC(f T>MIC). Methods: Clinical isolates of CR-AB from patients admitted to Phramongkutklao Hospital, Thailand from January 2014 to December 2015 were obtained. The MIC of sulbactam for each CR-AB isolate was determined using the agar dilution method. Each sulbactam regimen was simulated using the Monte Carlo technique to calculate the probability of target attainment(PTA) and the cumulative fraction of response(CFR) in critically ill patients. PTA was defined by how likely a specific drug dose was to reach 40% and 60% f T>MIC. The CFR was the probability of drug dose covering the MIC range of CR-AB. Dosing regimens reaching above 80% of PTA and CFR, were considered as the optimal dosage for documented and empirical therapy, respectively. Results: A total of 118 CR-AB isolates were included in the study. The percentile at the fiftieth and ninetieth MIC of sulbactam were 64 and 192 μg/m L, respectively. For a MIC of sulbactam of 4 μg/m L, all dosage regimens achieved PTA target. However, only a sulbactam dosage of 12 g intravenous daily using 2-4 h infusion or continuous infusion that covered for isolates with a sulbactam MIC of 96 μg/m L, met the PTA or CFR targets. Conclusions: The MIC of sulbactam against CR-AB is quite high. The sulbactam dose of 12 g/day using prolonged infusion was required to achieve the target f T>MIC for CR-AB treatment.
文摘Objective: The objective is to explore the mechanism of inhibitory effect of three main SCFAs (acetate, propionate and butyrate) on inflammatory response of A549 cells. Methods: Human lung adenocarcinoma cells (A549 cells) were cultured, and were divided into normal control group (NC group), A. baumannii infection group (A. baumannii group), NF-κB inhibitor group (JSH group), A. baumannii infection + sodium acetate group (NaAc group), A. baumannii infection + sodium propionate group (NaPc group) and A. baumannii infection + sodium butyrate group (NaB group). Real-time quantitative PCR was used to detect the mRNA expression of NLRP3, Caspase-1, IL-1β, IL-6, and TGF-β in A549 cells. Western blotting assay was used to determine the expression of autophagy and “pyroptosis” related proteins of NRLP3, cleaved-Caspase-1 (P20), GSDMD (P30), LC-3 and Beclin-1. At the same time, the expression of NF-κB p65 protein in nucleus and cytoplasm of A549 cells was detected. The level of reactive oxygen species in A549 cells was detected by flow cytometry. Results: Compared with A. baumannii group, the mRNA expression of NLRP3, IL-1β and IL-6 in NaAc group, NaPc group and NaB group decreased significantly, the mRNA expression of Caspase-1 in NaPc group and NaB group decreased significantly, only the mRNA expression of TGF-β in NaB group increased significantly;LC3-II expression increased significantly in NaPc group and NaB group, only Beclin-1 expression increased and GSDMD (p30) expression decreased significantly in NaB group. All three kinds of SCFAs could significantly inhibit the expression of cleaved-Caspase-1 (p20) after A. baumannii infection, but there was no significant change in the protein expression of NLRP3. Compared with NC group, the production of reactive oxygen species in A. baumannii group increased significantly at 3 h after A. baumannii infection. Compared with A. baumannii group, NaB could significantly suppress the production of reactive oxygen species induced by A. baumannii. Compared with A. baumannii group, the expression of NF-κB p65 in nucleus was significantly decreased and the expression of NF-κB p65 in cytoplasm was significantly increased after 24 h pre-incubation with NaB, NaPc and NaAc, respectively. Conclusion: A. baumannii can induce inflammatory injury of pulmonary epithelial cells, and the three major SCFAs can inhibit the activation of NLRP3 inflammasome and the release of pro-inflammatory factors through NF-κB/ROS/NLRP3 pathway, which provides a new way for clinical prevention of severe inflammatory injury caused by A. baumannii infection.
文摘Acinetobacter baumannii is one of the most prevalent pathogens in nosocomial infections and has been cause of concern in recent years because, it has presented multiresistance to antibiotics and besides can form biofilms on biotic and abiotic surfaces like tissues and medical devices. Therefore, the search for new alternatives of natural origin to inhibit biofilm formation is being conducted. In the present investigation, sub-lethal concentrations (5.61 mg/mL, 3.74 mg/mL and 1.87 mg/mL) of methanolic extract of Nothoscordum bivalve were evaluated, showing biofilm formation inhibition up to 40.8%, in one nosocomial isolated of A. baumannii by the microtiter biofilm formation assay using crystal violet. On the other hand, the concentrations of 5.61 mg/mL and 3.74 mg/mL, caused an overexpression (up to 15.4 times) in the genes involved in the formation of biofilm (abaI, bap and csuE);due to this, the interaction of the extract with the bacteria was analyzed by scanning electron microscopy (SEM) and cellular damage was observed in the structure and stability of biofilm.
文摘Emerging and rapidly spreading multidrug resistant bacteria constitute a rising public health concern worldwide. Acinetobacter baumannii is one of these bacteria that cause different infections including pneumonia, bacteremia, meningitis, soft-tissue, and urinary tract infections, and are associated with high mortality and economic burden. We present a case of a 43-year-old woman, admitted at the department of orthopedics, regional hospital of Ourossogui, North-East of Senegal for soft-tissue injuries. Initially diagnosed with Yersinia pestis infection, the patient was well managed before being released. Supplementary sampling for confirmatory tests allowed the detection of an extensively drug-resistant Acinetobacter baumannii clone.
文摘Model Study: The genus Acinetobacter is composed of opportunistic pathogens that mainly affects immunocompromised and patients during a prolonged hospitalization period. A. baumannii can survive in the hospital setting at various locations such as mechanical ventilators, dialysis machines, ventilation systems, water sources, skin and mucous membranes of health professionals and patients, drug preparations and disinfectants among others. Antimicrobials are essential for the treatment of infections, so their use has become common, and often inappropriate and abusive. This pathogen has presented multi-resistance to several classes of antimicrobials and has become a major cause of death in hospitals. Objective: To evaluate the occurrence of Acinetobacter baumannii in clinical samples from the Laboratory of Clinical Analyzes, HCSL of Pouso Alegre, MG. Methods: All the samples referring to the patients of the Samuel Libanio Clinical Hospital including most of the specialties were evaluated. From the positive samples for Acinetobacter baumannii the medical records of hospitalized patients were evaluated. From the medical records, data were obtained as gender and age of the patient, place of hospitalization, together with month and year of the laboratory procedure. Result: A total of 14,859 samples of diverse materials were evaluated, being 80 (0.5%) samples positive for Acinetobacter baumannii. Of these positive samples, the largest occurrences were identified in male patients 59 (73.7%), aged over 60 years 37 (46.3%). The most affected hospital sector was Adult ICU with 44 (55.0%) of the cases. In May 2015, there were 5 (6.3%) cases registered and in May 2016, 16 (20.0%) cases. The clinical material with the highest occurrence of Acinetobacter baumannii was Mini Bal 29 (36.3%). Conclusion: Acinetobacter baumannii has been presenting a major increase in clinical samples from the lungs, mainly from male, elderly patients hospitalized in an intensive care unit and with resistance to Polimixin.
文摘At present,the multiple drug resistance of Acinetobacter baumannii outbreaks worldwide and has intensified the trend,especially in the intensive care unit and burn ward.Generic drug resistant Acinetobacter baumannii is known as the 21st century gram-negative bacterium“MRSA”,“Superbugs”.In recent years,researches have shown that this is associated with pathogenic bacteria to form biofilms.In this paper,the status of Acinetobacter baumannii infection,biofilm formation,resistance mechanism and prevention in recent years were summarized.
