Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B ...Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B and E(colistin)constitute the last-line therapies for treating MDR Gram-negative bacteria.Polymyxin is a cationic antibacterial peptide that can destroy the outer membrane of Gram-negative bacteria.With the increasing clinical application of polymyxin,however,there have been many reports of the occurrence of polymyxin-resistant Gram-negative bacteria.This resistance is mainly mediated by the modification or complete loss of lipopolysaccharide(LPS).LPS is also a virulence factor of Gram-negative bacteria,and alterations of LPS may correlate with virulence.Although it is generally believed that the biological costs associated with drug resistance may enable benign susceptible bacteria to overcome resistant bacteria when antibiotic pressure is reduced,some studies have shown that polymyxin-resistant bacteria are associated with higher virulence and greater fitness compared with their susceptible counterparts.To predict the development of polymyxin resis-tance and evaluate interventions for its mitigation,it is important to understand the relative biological cost of polymyxin resistance compared with susceptibility.The impact of polymyxin resistance mecha-nisms on the virulence and fitness of these three Gram-negative bacteria are summarized in this review.展开更多
Antibiotic resistant bacteria pathogens remain the leading cause of shellfish borne diseases and a major health threat to humans worldwide. The objectives of this study were to isolate, identify, and determine the ant...Antibiotic resistant bacteria pathogens remain the leading cause of shellfish borne diseases and a major health threat to humans worldwide. The objectives of this study were to isolate, identify, and determine the antibiotic resistance patterns of Gram-negative bacteria from shellfish. We analyzed a total of 540 shellfish (117 clams, 88 oysters, and 136 periwinkles) samples collected from different vendors at Iko and Douglas Creeks in Akwa Ibom State, South-South Nigeria. Conventional cultural techniques, morphological, biochemical characteristics, and PCR amplification were used to identify the bacterial isolates. Antibiotic susceptibility tests (Kirby-Bauer disk diffusion method) and ESBL phenotype (disk) of the isolates were performed. One hundred and thirty-five (135) Gram-negative bacteria comprising 5 genera and 14 species were detected at a prevalence of: <i>Alcaligenes faecalis</i> <i><b>TRB</b></i>-7 38 (28.2%), <i>Pseudomonas oryzihabitans strain <b>KCB</i>005</b> 16 (11.9%), <i>Paenalcaligenes retgerii strain <b>B</i>5</b> 12 (8.9%) <i>Pseudomonas aeruginosa <b>JB</i>2</b> 10 (7.4%), <i>Providencia stuartii <b>DMC</i>-28b</b> 9 (6.7%), <i>Alcaligenes species <b>TLT</i>151</b> 8 (5.9%), <i>Pseudomonas aeruginosa <b>CIFRI DTSB</i>1</b> 7 (5.2%), <i>Paenalcaligenes species <b>UN</i>24</b> 7 (5.2%), <i>Alcaligenes faecalis <b>BT</i>10</b> 7 (5.2%), <i>Vibrio species strain <b>PrVy</i>108</b> 6 (4.4%), <i>Pseudomonas xiamenensis <b>C</i>10-2</b> 5 (3.7%), <i>Providencia vemicola <b>Bu</i>15_38</b> 4 (2.9%), <i>Pseudomonas anguillisceptica</i> <b>4029</b> 3 (2.2%), and <i>Pseudomonas aeruginosa <b>N</i>15-01092</b> 3 (2.2%). All tested isolates showed various degrees of resistance to the thirteen antimicrobials evaluated. High levels of resistance (100%) to cefepime and imipenem were expressed by all isolates except the <i>Providencia</i> species. For the EBSL indicators, all isolates apart from <i>Alcaligenes</i> species were resistant (100%) to ceftriaxone. All <i>Vibrio</i> species were susceptible to norfloxacin, nalidixic acid, and ceftazidime. The identification of antibiotic resistant Gram-negative bacteria (GNARB) from shellfish in this study highlights the risk of disseminated multi-drug resistance—a serious public health concern.展开更多
Introduction: Bacterial skin and soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient care visits whose causative agents are associated with a high antimicrobial resistance burden. For insig...Introduction: Bacterial skin and soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient care visits whose causative agents are associated with a high antimicrobial resistance burden. For insights on antimicrobial susceptibilities in a rural setting, we examined specimens from suspected SSTIs from two public health facilities in Kenya. We additionally assessed antibiotic use, appropriateness of empiric therapy and risk factors for SSTI. Methodology: Between 2021 and 2023, 265 patients at Kisii and Nyamira County Referral hospitals were enrolled. Wound swabs/aspirates were collected and processed following standard microbiological procedures. Identification and antimicrobial susceptibility were performed using the VITEK 2 Compact platform. Demographic, clinical, and microbiological data were analyzed with R Statistical software. Results: S. aureus was isolated in 16.2% (43/265) of patients with a methicillin resistance (MRSA) proportion of 14% (6/43). While 13/15 drugs elicited susceptibilities ranging from 84% - 100%, penicillin (16%) and trimethoprim-sulfamethoxazole [TMP-SXT] (23%) yielded the lowest susceptibilities. Escherichia coli (n = 33), Klebsiella pneumoniae (n = 8), Pseudomonas aeruginosa (n = 8), and Citrobacter species (n = 4) were the most commonly isolated gram-negative species. Gram-negative strains showed high susceptibilities to most of the tested drugs (71% - 100%) with the exception of ampicillin (18%), TMP-SXT (33%), and first and second generation cephalosporins. Conclusions: The low MRSA prevalence and generally high antibiotic susceptibilities for S. aureus and gram-negative bacteria present opportunities for antibiotic stewardship in the study setting. Diminished susceptibilities against penicillin/ampicillin and TMP-SXT accord with prevailing local data and add a layer of evidence for their cautious empiric use.展开更多
A series of new monobactam sulfonates is continuously synthesized and evaluated for their antimicrobial efficacies against Gram-negative bacteria.Compound 33a(IMBZ18G)is highly effective in vitro and in vivo against c...A series of new monobactam sulfonates is continuously synthesized and evaluated for their antimicrobial efficacies against Gram-negative bacteria.Compound 33a(IMBZ18G)is highly effective in vitro and in vivo against clinically intractable multi-drug-resistant(MDR)Gram-negative strains,with a highly druglike nature.The checkerboard assay reveals its significant synergistic effect withβ-lactamase inhibitor avibactam,and the MIC values against MDR enterobacteria were reduced up to 4—512folds.X-ray co-crystal and chemoproteomic assays indicate that the anti-MDR bacteria effect of 33a results from the dual inhibition of the common PBP3 and some class A and Cβ-lactamases.Accordingly,preclinical studies of 33a alone and 33a-avibactam combination as potential innovative candidates are actively going on,in the treatment ofβ-lactamase-producing MDR Gram-negative bacterial infections.展开更多
Cell-cell communication is critical for bacterial survival in natural habitats,in which miscellaneous regulatory networks are encompassed.However,elucidating the interaction networks of a microbial community has been ...Cell-cell communication is critical for bacterial survival in natural habitats,in which miscellaneous regulatory networks are encompassed.However,elucidating the interaction networks of a microbial community has been hindered by the population complexity.This study reveals thatγ-butyrolactone(GBL)molecules from Streptomyces species,the major antibiotic producers,can directly bind to the acyl-homoserine lactone(AHL)receptor of Chromobacterium violaceum and influence violacein production controlled by the quorum sensing(QS)system.Subsequently,the widespread responses of more Gram-negative bacterial AHL receptors to Gram-positive Streptomyces signaling molecules are unveiled.Based on the cross-talk between GBL and AHL signaling systems,combinatorial regulatory circuits(CRC)are designed and proved to be workable in Escherichia coli(E.coli).It is significant that the QS systems of Gram-positive and Gram-negative bacteria can be bridged via native Streptomyces signaling molecules.These findings pave a new path for unlocking the comprehensive cell-cell communications in microbial communities and facilitate the exploitation of innovative regulatory elements for synthetic biology.展开更多
Alzheimer's disease(AD)is the most serious age-related neurodegenerative disease and causes destructive and irreversible cognitive decline.Failures in the development of therapeutics targeting amyloid-β(Aβ)and t...Alzheimer's disease(AD)is the most serious age-related neurodegenerative disease and causes destructive and irreversible cognitive decline.Failures in the development of therapeutics targeting amyloid-β(Aβ)and tau;principal proteins inducing pathology in AD,suggest a paradigm shift towards the development of new therapeutic targets.The gram-negative bacteria and lipopolysaccharides(LPS)are attractive new targets for AD treatment.Surprisingly,an altered distribution of gram-negative bacteria and their LPS has been reported in AD patients.Moreover,gram-negative bacteria and their LPS have been shown to affect a variety of AD-related pathologies,such as Aβ homeostasis,tau pathology,neuroinflammation,and neurodegeneration.Moreover,therapeutic approaches targeting gram-negative bacteria or gram-negative bacterial molecules have significantly alleviated AD-related pathology and cognitive dysfunction.Despite multiple evidence showing that the gram-negative bacteria and their LPS play a crucial role in AD pathogenesis,the pathogenic mechanisms of gram-negative bacteria and their LPS have not been clarified.Here,we summarize the roles and pathomechanisms of gram-negative bacteria and LPS in AD.Furthermore,we discuss the possibility of using gram-negative bacteria and gram-negative bacterial molecules as novel therapeutic targets and new pathological characteristics for AD.展开更多
The sensitive and differential detection of Gram-negative bacteria is essential in food processing,environmental monitoring,and the daily chemical industry.Herein,we propose and validate a liquid crystal(LC)-based apt...The sensitive and differential detection of Gram-negative bacteria is essential in food processing,environmental monitoring,and the daily chemical industry.Herein,we propose and validate a liquid crystal(LC)-based aptasensor for the ultrasensitive detection of Escherichia coli(E.coli),a model of Gram-negative bacteria.The nematic liquid crystal of 4-cyano-4’-pentylbiphenyl(5 CB) molecules can be orderly or disorderly arranged at the LC-aqueous interface via different stimuli,causing changes in optical texture due to birefringence.Bright schlieren texture is observed when a mixture solution of aptamer and hexadecyl trimethyl ammonium bromide(CTAB) is dripped onto the segmented LC films on a copper mesh.The specific binding of aptamers with target bacteria biomarkers liberates the CTAB molecules,which then self-assemble at the LC-aqueous interface to induce the vertical alignment of LCs.An optical transition from bright to dark is therefore achieved via the LC molecular orientation and serves as an aptasensor.Given the prominent affinity and specificity of the aptamer,the established sensitive and selective E.coli assay shows an ultralow detection limit of 27 cfu/mL.The prepared aptasensor can also be applied for the sensitive and selective determination of E.coli in fruit juice,soft drink,and cosmetic products,and shows great promise for the on-site detection of Gram-negative bacteria with high sensitivity and specificity for environmental monitoring,food safety assessment,and household chemical inspection.展开更多
Mg and its alloys are suitable choices for implant materials due to their biodegradability and biocompatibility features. However, the high electrochemical activity of this family of biomaterials results in their fast...Mg and its alloys are suitable choices for implant materials due to their biodegradability and biocompatibility features. However, the high electrochemical activity of this family of biomaterials results in their fast degradation and severe corrosion in the physiological environment,producing hydrogen(H;) gas, and therefore increasing the p H of the environment. To meet the clinical requirements, the degradation rate of Mg biomaterials needs to be reduced. Nevertheless, higher corrosion resistance of Mg results in a low alkaline p H, weakening the antibacterial activity. Therefore, while the rapid degradation problem of Mg-based biomaterials needs to be addressed, good antibacterial properties are also necessary. By using the plasma electrolytic oxidation(PEO) surface modification technique, the antibacterial activity of Mg and its alloys can be enhanced while maintaining their corrosion protection properties at a high level. Throughout the PEO process, introducing antibacterial agents into solutions results in a major increase in antibacterial activity of the coatings. Moreover, post-or pre-processing on PEO coatings can provide better protection against bacteria. In this review, the antibacterial activity of PEO coatings applied on Mg and also its alloys will be discussed in more detail.展开更多
It is known that the consumption of bacteria such as lactobacilli and bifidobacteria has beneficial effects on human immune function. Most of them are Gram-positive bacteria, and there are few reports on Gram-negative...It is known that the consumption of bacteria such as lactobacilli and bifidobacteria has beneficial effects on human immune function. Most of them are Gram-positive bacteria, and there are few reports on Gram-negative bacteria. In this study, we evaluated the effects of intake of Gluconacetobacter hansenii GK-1 (GK-1), Gram-negative acetic acid bacteria, for 12 weeks on physical condition and immune indices. We conducted a randomized, double-blind, placebo-controlled, parallel-group study in 100 healthy adults. The subjects were randomized into the GK-1 and the placebo groups. The diary-administered physical condition survey was conducted during the study period. The evaluation of salivary sIgA levels, NK-cell activity, and serum IFN-γ levels and quality of life survey was conducted before, in 6 weeks, and 12 weeks after the start of ingestion. Based on the physical condition survey, the cumulative onset-days of symptoms were significantly suppressed in the GK-1 group compared to the placebo group regarding the evaluation of 13 symptoms related to immunity, every 3 weeks. Additionally, salivary sIgA levels per hour were significantly increased in the GK-1 group compared with the placebo group at 6 and 12 weeks. Despite no significant differences in the NK-cell activity, serum IFN-γ levels or quality of life survey between the groups. Serum IFN-γ levels in the GK-1 group were significantly elevated at 12 weeks after the start of ingestion compared with those before ingestion. In conclusion, intake of GK-1 was shown to increase salivary sIgA levels and improve physical condition. This suggested that oral intake of GK-1 may help maintain the immune system.展开更多
The study is to identify trends and levels of antibiotic resistance of some common Gram-negative strains over time. The samples were collected from Vietnam Military Hospital 103 between 2014 and 2019. A total of 405 &...The study is to identify trends and levels of antibiotic resistance of some common Gram-negative strains over time. The samples were collected from Vietnam Military Hospital 103 between 2014 and 2019. A total of 405 <i>Acinetobacter baumannii</i>., 528 <i>Pseudomonas aeruginosa</i>, 741 <i>Escherichia coli</i>, and 352 <i>Klebsiella pneumoniae</i> strains were identified and antimicrobial susceptibility was by Vitek system and Etest method. The multi-drug resistance (MDR) was major proportion of four common bacteria. In particular, there is a tendency to shift from MDR to Extended drug resistance (XDR) or possibly Pan drug resistant (pPDR). <i>A. baumannii</i> had the highest level of antibiotic resistance, namely, carbapenem (61.5% - 82.5%) and cephalosporin (72.7% - 88.7%). <i>P. aeruginosa</i> resisted most of commonly antibiotics, ranging from 50% to 70%. <i>E. coli</i> had a high resistance with antibiotics like ampicillin (87.2% - 97.6%) and the 3rd generation cephalosporins (up to 79.6%). <i>K. pneumoniae</i> resisted carbapenem from 14.7% to 44.4%, and other antibiotics with the higher rate of 40%. The collected data will be a prerequisite for further studies on mechanisms and factors related to antibiotic resistant bacteria, in order to find out a rational and effective using strategy of antibiotics.展开更多
Objective To investigate the distribution and antimicrobial susceptibility of causative microorganisms recovered from patients with intra-abdominal infections(IAIs).Methods A total of 2,926 bacterial and fungal strain...Objective To investigate the distribution and antimicrobial susceptibility of causative microorganisms recovered from patients with intra-abdominal infections(IAIs).Methods A total of 2,926 bacterial and fungal strains were identified in samples collected from 1,679 patients with IAIs at the Peking Union Medical College Hospital between 2011 and 2021.Pathogenic bacteria and fungi were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.Antimicrobial susceptibility testing(AST)was performed using the VITEK 2 compact system and the Kirby–Bauer method.AST results were interpreted based on the M100-Ed31 clinical breakpoints of the Clinical and Laboratory Standards Institute.Results Of the 2,926 strains identified,49.2%,40.8%,and 9.5%were gram-negative bacteria,gram-positive bacteria,and fungi,respectively.Escherichia coli was the most prevalent pathogen in intensive care unit(ICU)and non-ICU patients;however,a significant decrease was observed in the isolation of E.coli between 2011 and 2021.Specifically,significant decreases were observed between 2011 and 2021 in the levels of extended-spectrumβ-lactamase(ESBL)-producing E.coli(from 76.9%to 14.3%)and Klebsiella pneumoniae(from 45.8%to 4.8%).Polymicrobial infections,particularly those involving co-infection with gram-positive and gram-negative bacteria,were commonly observed in IAI patients.Moreover,Candida albicans was more commonly isolated from hospital-associated IAI samples,while Staphylococcus epidermidis had a higher ratio in community-associated IAIs.Additionally,AST results revealed that most antimicrobial agents performed better in non-ESBL-producers than in ESBL-producers,while the overall resistance rates(56.9%–76.8%)of Acinetobacter baumanmii were higher against all antimicrobial agents than those of other common gram-negative bacteria.Indeed,Enterococcus faecium,Enterococcus faecalis,S.epidermidis,and S.aureus were consistently found to be susceptible to vancomycin,teicoplanin,and linezolid.Similarly,C.albicans exhibited high susceptibility to all the tested antifungal drugs.Conclusion The distribution and antimicrobial susceptibility of the causative microorganisms from patients with IAls were altered between 2011 and 2021.This finding is valuable for the implementation of evidence-based antimicrobial therapy and provides guidance for the control of hospital infections.展开更多
Infectious diseases become one of the leading causes of human death. Traditional treatment based on classical antibiotics could not provide enough antibacterial activity to combat bacterial infections due to low bioav...Infectious diseases become one of the leading causes of human death. Traditional treatment based on classical antibiotics could not provide enough antibacterial activity to combat bacterial infections due to low bioavailability, even leading to antibiotic resistance. In recent years, biomimetic delivery systems have been developed to improve drug therapy for various diseases, such as malignant tumor and cardiovascular disease. In this work, we designed virus-inspired nanodrugs(VNDs) through co-assembly of amphiphilic lipopeptide dendrons and poly(lactic-co-glycolic acid) polymers for high-efficiency antibiotic delivery. These VNDs had well-defined and stable nanostructures for tetracycline encapsulation and delivery. The VNDs were capable of promoting antibiotic internalization and enhancing their antibacterial effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Additionally, no obvious cytotoxicity of VNDs was observed to human cell lines. This work successfully demonstrated the virus-mimetic nanoparticles served as promising and applicable antibiotic delivery platform for antibacterial treatment.展开更多
BACKGROUND Diabetic foot ulceration(DFU)is the prime health concern globally.It accounts for the major burden related to disease mortality and morbidity and economic cost.The timely and early recognition of the DFU ca...BACKGROUND Diabetic foot ulceration(DFU)is the prime health concern globally.It accounts for the major burden related to disease mortality and morbidity and economic cost.The timely and early recognition of the DFU can help present its occurrence and improve clinical outcomes.AIM To evaluate interrelationships between foot ulcers,risk factors,and antibiotic resistance among diabetic patients having ulcers in their foot.METHODS The databases such as PubMed,ERIC,Medline,and Google Scholar were extensively used for the extraction of studies.The selected studies were published within the time-period of 2014-2018.Ten studies were selected,which were found to be completely relevant to the current study.RESULTS The prevalence of diabetic foot ulcers among the population was evaluated,and the associated risk factors with its prevalence.Moreover,few studies also reported on the bacteria that are found to be most prevailing among diabetic patients.A narrative discussion was drawn through this analysis,which was used to highlight the specific area of research through selected studies,extraction of the significant information that matched with the topic of research,and analysis of problem through the findings of the selected articles.The results helped in assessing significant knowledge regarding the risk factors of diabetic foot ulcers and the role of antimicrobial resistant in its treatment.CONCLUSION The gram-negative bacteria were found to be the most common reason for diabetic foot ulcers.The study only included 10 studies that are not sufficient to produce generalized results,and no information was reported on the tests required to analyze antimicrobial susceptibility that can guide clinicians to propose better and sound treatment plans.It is evident that most study results depicted that the most common risk factors were found to be hypertension and neuropathy.展开更多
<b>Introduction:</b> Oral cancer is the third most prominent type of cancer in Bangladesh. During or after oral cancer treatment, immune-compromised cancer patients may be susceptible to an infection by mu...<b>Introduction:</b> Oral cancer is the third most prominent type of cancer in Bangladesh. During or after oral cancer treatment, immune-compromised cancer patients may be susceptible to an infection by multi-drug-resistant opportunistic microbes. This study aims to identify the prevalent microorganisms from the infected site of oral cancer patients and observe their antibiotic susceptibility pattern. <b>Materials and Methods:</b> Clinical samples were collected from the infected sites of oral cancer patients and healthy people. The swabs collected were placed on nutrient agar slant, then incubated for 24 hours at 37ºC. Bacteria from the slant were inoculated in several selective media (Mannitol Salt Agar Media, KF Streptococcus Agar media, Cetrimide Agar, Eosin Methylene Blue Agar). Several biochemical tests identified opportunistic microorganisms. Finally, the antibiotic susceptibility test was performed by the Kirby Bauer disc diffusion method. <b>Results:</b> The study found that 65.4% of microbes isolated from the patients’ oral cavities were Gram-negative bacteria, and 34.6% were Gram-positive bacteria. Among the patient group isolates (n = 55), the most prevalent organism was <i>Pseudomonas</i> spp. (30;54.54%). Others were <i>Klebsiella</i> spp. (27;49.09%), <i>Staphylococcus</i> spp. (24;43.63%), <i>E. coli</i> (14;25.45%), <i>Streptococcus</i> spp. (14;25.45%), <i>Proteus</i> spp. (12;21.8%) and <i>Enterococcus</i> spp. (6;10.90%). Both Gram-positive and Gram-negative microbes from the patient group have shown high resistance to the commonly used antibiotics. In the control group (n = 50), the most prevalent organism was <i>Staphylococcus</i> spp. (15;30%). Other organisms were <i>Streptococcus</i> spp. (6;12%), <i>Klebsiella</i> spp. (11;22%), <i>E. coli</i> (3;6%), <i>Streptococcus</i> spp. (14;25.45%), <i>Pseudomonas</i> spp. (8;16%). The microbes of the control group showed less resistance to the antibiotics and rather showed sensitivity to them. <b>Conclusion:</b> The study revealed a high prevalence of multi-drug-resistant opportunistic microbes on immune-compromised oral cancer patients compared to microbes isolated from healthy people’s oral cavity.展开更多
Rationale:Infectious keratopathy is an ocular emergency with the potential to cause irreversible blindness.Patient's concerns:A 63-year-old diabetic man presented with a 3-day history of painful red right eye.He h...Rationale:Infectious keratopathy is an ocular emergency with the potential to cause irreversible blindness.Patient's concerns:A 63-year-old diabetic man presented with a 3-day history of painful red right eye.He had a history of multiple ocular surgeries in the affected eye without recent ocular trauma.Diagnosis:Infective crystalline keratopathy secondary to Citrobacter koseri.Interventions:Topical corticosteroids were discontinued,and dual topical antibiotic therapy of moxifloxacin 5%and gentamycin 0.3%were applied.Outcomes:Twelve hours after the start of treatment,the crystalline nature of the infiltrate disappeared,with enlargement of the epithelial defect.The antibiotic regime was continued and the lesion healed within a week of presentation with residual scarring.Lessons:Infective crystalline keratopathy classically presents with intrastromal branching fern-like opacities and minimal anterior segment inflammation in an immunosuppressed eye.The mainstay of management is corticosteroid discontinuation and the administration of empirical antibiotics until the results of the culture and sensitivity are available.In Citrobacter-related cases,treatment may result in a suppurative appearance before healing of the lesion.展开更多
OBJECTIVE:To investigate the anti-bacterial and anti-viral effects of Fengreqing oral liquid(风热清口服液,FRQ)in vitro and in vivo.METHODS:The minimum inhibitory concentrations of Fengreqing Oral Liquid against six gr...OBJECTIVE:To investigate the anti-bacterial and anti-viral effects of Fengreqing oral liquid(风热清口服液,FRQ)in vitro and in vivo.METHODS:The minimum inhibitory concentrations of Fengreqing Oral Liquid against six gram-positive bacteria(Staphylococcus aureus,Streptococcus mutans,Peptostreptococcus anaerobius,Hemolytic streptococcus,Streptococcus pneumoniae,Klebsiella pneumoniae),seven gram-negative bacteria(Escherichia coli,Actinobacillus actinomycetemcomitans,Porphyromonas gingivalis,Haemophilus influenzae,Helicobacter pylori,Pseudomonas aeruginosa,Gardnerella vaginalis)and Candida albicans were detected by the paper disc diffusion method.The inhibition rate of A/Puerto Rico/8/34(H1N1)(PR8)influenza virus in different concentrations of Fengreqing oral solution was detected by chicken embryo method.CCK8 method was used to detect the half-cell infection of RSV,VSV and CVB3.The effect of FRQ on the survival curve of mice was detected by using co-infection model of Streptococcus pneumoniae and influenza virus.RESULTS:In vitro,FRQ can inhibit Actinobacillus actinomycetemcomitans,Helicobacter pylori,Gardnerella vaginalis,Staphylococcus aureus,Streptococcus mutans and Streptococcus pneumoniae and has an antiviral effect on the envelope virus H1N1.In vivo,Fengreqing oral solution had therapeutic effect on influenza-Streptococcus pneumoniae co-infection in mice,significantly improving the survival rate of mice.The medium dose and low dose FRQ significantly prolonged the survival time of mice.CONCLUSION:FRQ has good anti-bacterial and anti-viral effects in vivo and in vitro.展开更多
Objective:To estimate the fatty acids content in the brown algae Padina pavonica(P.pavonica)and Hormophysa triquetra(H.triquetra)and evaluate their potential antimicrobial activity as bioactive compounds.Methods:The f...Objective:To estimate the fatty acids content in the brown algae Padina pavonica(P.pavonica)and Hormophysa triquetra(H.triquetra)and evaluate their potential antimicrobial activity as bioactive compounds.Methods:The fatty acid compositions of the examined species were analyzed using gas chromatography-mass spectrometry.The antimicrobial activity of crude and fatty acids was assessed using the agar plug technique.Results:The fatty acids profile ranged from C8:0 to C20:4.Concentration of saturated fatty acids in P.pavonica was in the order palmitic>myristic>stearic whereas concentration of the unsaturated fatty acids was oleic acid>palmitoleic>9-cis-hexadecenoic>linoleic acid>α-linolenic>arachidonic>elaidic acid.H.triquetra contained high concentration of saturated fatty acids than those of P.pavonica which was in the order as follows:palmitic>margaric>myristic>nonadecyclic>stearic>caprylic>tridecylic>pentadecylic>lauric while the unsaturated fatty acids consisted of oleic>nonadecenoic>non adecadienoate>margaroleic.The crude and fatty acid extracts of H.triquetra and P.pavonica were biologically active on the tested pathogens.H.triquetra exhibited a larger inhibitory zone than P.pavonica.Conclusions:The brown algae P.pavonica and H.triquetra have high efficient amount of fatty acids and showed strong antibacterial activity,especially H.triquetra.展开更多
The innate immune responses,including inflammasome activation,are paramount for host defense against pathogen infection.In contrast to canonical and noncanonical inflammasome activation,in this study,heat-killed gram-...The innate immune responses,including inflammasome activation,are paramount for host defense against pathogen infection.In contrast to canonical and noncanonical inflammasome activation,in this study,heat-killed gram-negative bacteria(HK bacteria)were identified as single-step stimulators of the NLRP3 inflammasome in human monocytes,and they caused a moderate amount of IL-1βto be released from cells.Time course experiments showed that this alternative inflammasome response was finished within a few hours.Further analysis showed that the intrinsically limited NLRP3 inflammasome activation response was due to the negative regulation of caspase-8 by the short isoform of cFLIP(cFLIPs),which was activated by NF-κB.In contrast,overexpressed cFLIPS,but not overexpressed cFLIPL,inhibited the activation of caspase-8 and the release of IL-1βin response to HK bacteria infection in human monocytes.Furthermore,we demonstrated that TAK1 activity mediated the expression of cFLIPs and was upstream and essential for the caspase-8 cleavage induced by HK bacteria in human monocytes.The functional specificity of cFLIPs and TAK1 revealed unique responses of human monocytes to a noninvasive pathogen,providing novel insights into an alternative regulatory pathway of NLRP3 inflammasome activation.展开更多
The rise of resistance to all known antibiotics is a global crisis.In addition to novel treatment options,there is an urgent need to develop rapid,specific,sensitive,and reliable diagnostic methods to detect pathogeni...The rise of resistance to all known antibiotics is a global crisis.In addition to novel treatment options,there is an urgent need to develop rapid,specific,sensitive,and reliable diagnostic methods to detect pathogenic bacteria in clinical samples and reduce the overuse and misuse antibiotics.Pseudopaline,a metallophore produced by the human pathogen Pseudomonas aeruginosa,transports divalent metal ions via a dedicated active transport system,making it an ideal carrier for a second functional moiety.展开更多
基金supported by the National Key Research and Development Program of China (2017YFC1600100 and2017YFC1200203)the National Natural Science Foundation of China (81702040)the National Science Foundation of Zhejiang Province,China (LY20H190002)
文摘Humanity is facing an enormous and growing worldwide threat from the emergence of multi-drug-resistant(MDR)Gram-negative bacteria such as Escherichia coli,Klebsiella pneumoniae,and Acinetobacter baumannii.Polymyxin B and E(colistin)constitute the last-line therapies for treating MDR Gram-negative bacteria.Polymyxin is a cationic antibacterial peptide that can destroy the outer membrane of Gram-negative bacteria.With the increasing clinical application of polymyxin,however,there have been many reports of the occurrence of polymyxin-resistant Gram-negative bacteria.This resistance is mainly mediated by the modification or complete loss of lipopolysaccharide(LPS).LPS is also a virulence factor of Gram-negative bacteria,and alterations of LPS may correlate with virulence.Although it is generally believed that the biological costs associated with drug resistance may enable benign susceptible bacteria to overcome resistant bacteria when antibiotic pressure is reduced,some studies have shown that polymyxin-resistant bacteria are associated with higher virulence and greater fitness compared with their susceptible counterparts.To predict the development of polymyxin resis-tance and evaluate interventions for its mitigation,it is important to understand the relative biological cost of polymyxin resistance compared with susceptibility.The impact of polymyxin resistance mecha-nisms on the virulence and fitness of these three Gram-negative bacteria are summarized in this review.
文摘Antibiotic resistant bacteria pathogens remain the leading cause of shellfish borne diseases and a major health threat to humans worldwide. The objectives of this study were to isolate, identify, and determine the antibiotic resistance patterns of Gram-negative bacteria from shellfish. We analyzed a total of 540 shellfish (117 clams, 88 oysters, and 136 periwinkles) samples collected from different vendors at Iko and Douglas Creeks in Akwa Ibom State, South-South Nigeria. Conventional cultural techniques, morphological, biochemical characteristics, and PCR amplification were used to identify the bacterial isolates. Antibiotic susceptibility tests (Kirby-Bauer disk diffusion method) and ESBL phenotype (disk) of the isolates were performed. One hundred and thirty-five (135) Gram-negative bacteria comprising 5 genera and 14 species were detected at a prevalence of: <i>Alcaligenes faecalis</i> <i><b>TRB</b></i>-7 38 (28.2%), <i>Pseudomonas oryzihabitans strain <b>KCB</i>005</b> 16 (11.9%), <i>Paenalcaligenes retgerii strain <b>B</i>5</b> 12 (8.9%) <i>Pseudomonas aeruginosa <b>JB</i>2</b> 10 (7.4%), <i>Providencia stuartii <b>DMC</i>-28b</b> 9 (6.7%), <i>Alcaligenes species <b>TLT</i>151</b> 8 (5.9%), <i>Pseudomonas aeruginosa <b>CIFRI DTSB</i>1</b> 7 (5.2%), <i>Paenalcaligenes species <b>UN</i>24</b> 7 (5.2%), <i>Alcaligenes faecalis <b>BT</i>10</b> 7 (5.2%), <i>Vibrio species strain <b>PrVy</i>108</b> 6 (4.4%), <i>Pseudomonas xiamenensis <b>C</i>10-2</b> 5 (3.7%), <i>Providencia vemicola <b>Bu</i>15_38</b> 4 (2.9%), <i>Pseudomonas anguillisceptica</i> <b>4029</b> 3 (2.2%), and <i>Pseudomonas aeruginosa <b>N</i>15-01092</b> 3 (2.2%). All tested isolates showed various degrees of resistance to the thirteen antimicrobials evaluated. High levels of resistance (100%) to cefepime and imipenem were expressed by all isolates except the <i>Providencia</i> species. For the EBSL indicators, all isolates apart from <i>Alcaligenes</i> species were resistant (100%) to ceftriaxone. All <i>Vibrio</i> species were susceptible to norfloxacin, nalidixic acid, and ceftazidime. The identification of antibiotic resistant Gram-negative bacteria (GNARB) from shellfish in this study highlights the risk of disseminated multi-drug resistance—a serious public health concern.
文摘Introduction: Bacterial skin and soft tissue infections (SSTIs) are a cause of frequent inpatient and outpatient care visits whose causative agents are associated with a high antimicrobial resistance burden. For insights on antimicrobial susceptibilities in a rural setting, we examined specimens from suspected SSTIs from two public health facilities in Kenya. We additionally assessed antibiotic use, appropriateness of empiric therapy and risk factors for SSTI. Methodology: Between 2021 and 2023, 265 patients at Kisii and Nyamira County Referral hospitals were enrolled. Wound swabs/aspirates were collected and processed following standard microbiological procedures. Identification and antimicrobial susceptibility were performed using the VITEK 2 Compact platform. Demographic, clinical, and microbiological data were analyzed with R Statistical software. Results: S. aureus was isolated in 16.2% (43/265) of patients with a methicillin resistance (MRSA) proportion of 14% (6/43). While 13/15 drugs elicited susceptibilities ranging from 84% - 100%, penicillin (16%) and trimethoprim-sulfamethoxazole [TMP-SXT] (23%) yielded the lowest susceptibilities. Escherichia coli (n = 33), Klebsiella pneumoniae (n = 8), Pseudomonas aeruginosa (n = 8), and Citrobacter species (n = 4) were the most commonly isolated gram-negative species. Gram-negative strains showed high susceptibilities to most of the tested drugs (71% - 100%) with the exception of ampicillin (18%), TMP-SXT (33%), and first and second generation cephalosporins. Conclusions: The low MRSA prevalence and generally high antibiotic susceptibilities for S. aureus and gram-negative bacteria present opportunities for antibiotic stewardship in the study setting. Diminished susceptibilities against penicillin/ampicillin and TMP-SXT accord with prevailing local data and add a layer of evidence for their cautious empiric use.
基金supported by CAMS Innovation Fund for Medical Sciences(2021-12M-1-070)National Natural Science Foundation of China(32141003)。
文摘A series of new monobactam sulfonates is continuously synthesized and evaluated for their antimicrobial efficacies against Gram-negative bacteria.Compound 33a(IMBZ18G)is highly effective in vitro and in vivo against clinically intractable multi-drug-resistant(MDR)Gram-negative strains,with a highly druglike nature.The checkerboard assay reveals its significant synergistic effect withβ-lactamase inhibitor avibactam,and the MIC values against MDR enterobacteria were reduced up to 4—512folds.X-ray co-crystal and chemoproteomic assays indicate that the anti-MDR bacteria effect of 33a results from the dual inhibition of the common PBP3 and some class A and Cβ-lactamases.Accordingly,preclinical studies of 33a alone and 33a-avibactam combination as potential innovative candidates are actively going on,in the treatment ofβ-lactamase-producing MDR Gram-negative bacterial infections.
基金supported by the National Key Research and Development Program of China(2018YFA0901900 and 2020YFA0907700)the National Natural Science Foundation of China(31771378 and 31800029)。
文摘Cell-cell communication is critical for bacterial survival in natural habitats,in which miscellaneous regulatory networks are encompassed.However,elucidating the interaction networks of a microbial community has been hindered by the population complexity.This study reveals thatγ-butyrolactone(GBL)molecules from Streptomyces species,the major antibiotic producers,can directly bind to the acyl-homoserine lactone(AHL)receptor of Chromobacterium violaceum and influence violacein production controlled by the quorum sensing(QS)system.Subsequently,the widespread responses of more Gram-negative bacterial AHL receptors to Gram-positive Streptomyces signaling molecules are unveiled.Based on the cross-talk between GBL and AHL signaling systems,combinatorial regulatory circuits(CRC)are designed and proved to be workable in Escherichia coli(E.coli).It is significant that the QS systems of Gram-positive and Gram-negative bacteria can be bridged via native Streptomyces signaling molecules.These findings pave a new path for unlocking the comprehensive cell-cell communications in microbial communities and facilitate the exploitation of innovative regulatory elements for synthetic biology.
基金funded by the Basic Science Research Program of the National Research Foundation of Korea(NRF)which is funded by the Ministry of Science,ICT&Future Planning(NRF-2018R1D1A3B07041059 to M.M.and NRF-2016R1A5A2012284 to Y.-M.R)+3 种基金by the Cooperative Research Program for Agriculture Science and Technology Development(Project No.PJ01428603)Rural Development Administration,Republic of Koreaby the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare,Republic of Korea(grant number:HF21C0021).
文摘Alzheimer's disease(AD)is the most serious age-related neurodegenerative disease and causes destructive and irreversible cognitive decline.Failures in the development of therapeutics targeting amyloid-β(Aβ)and tau;principal proteins inducing pathology in AD,suggest a paradigm shift towards the development of new therapeutic targets.The gram-negative bacteria and lipopolysaccharides(LPS)are attractive new targets for AD treatment.Surprisingly,an altered distribution of gram-negative bacteria and their LPS has been reported in AD patients.Moreover,gram-negative bacteria and their LPS have been shown to affect a variety of AD-related pathologies,such as Aβ homeostasis,tau pathology,neuroinflammation,and neurodegeneration.Moreover,therapeutic approaches targeting gram-negative bacteria or gram-negative bacterial molecules have significantly alleviated AD-related pathology and cognitive dysfunction.Despite multiple evidence showing that the gram-negative bacteria and their LPS play a crucial role in AD pathogenesis,the pathogenic mechanisms of gram-negative bacteria and their LPS have not been clarified.Here,we summarize the roles and pathomechanisms of gram-negative bacteria and LPS in AD.Furthermore,we discuss the possibility of using gram-negative bacteria and gram-negative bacterial molecules as novel therapeutic targets and new pathological characteristics for AD.
基金supported by Guangdong Province Basic and Applied Basic Research Foundation (2021A1515110236)the National Natural Science Foundation of China (62004070)+4 种基金the Science and Technology Program of Guangzhou (2019050001,202201010248)the Youth Innovation Project of Guangdong Education Department(2020KQNCX018)the Young Scholar Foundation of South China Normal University (21KJ08)the “Climbing Program” Special Funds of Guangdong Province (pdjh2022b0133)partially supported by the Science and Technology Planning Project of Guangdong Province (2020B1212060067)
文摘The sensitive and differential detection of Gram-negative bacteria is essential in food processing,environmental monitoring,and the daily chemical industry.Herein,we propose and validate a liquid crystal(LC)-based aptasensor for the ultrasensitive detection of Escherichia coli(E.coli),a model of Gram-negative bacteria.The nematic liquid crystal of 4-cyano-4’-pentylbiphenyl(5 CB) molecules can be orderly or disorderly arranged at the LC-aqueous interface via different stimuli,causing changes in optical texture due to birefringence.Bright schlieren texture is observed when a mixture solution of aptamer and hexadecyl trimethyl ammonium bromide(CTAB) is dripped onto the segmented LC films on a copper mesh.The specific binding of aptamers with target bacteria biomarkers liberates the CTAB molecules,which then self-assemble at the LC-aqueous interface to induce the vertical alignment of LCs.An optical transition from bright to dark is therefore achieved via the LC molecular orientation and serves as an aptasensor.Given the prominent affinity and specificity of the aptamer,the established sensitive and selective E.coli assay shows an ultralow detection limit of 27 cfu/mL.The prepared aptasensor can also be applied for the sensitive and selective determination of E.coli in fruit juice,soft drink,and cosmetic products,and shows great promise for the on-site detection of Gram-negative bacteria with high sensitivity and specificity for environmental monitoring,food safety assessment,and household chemical inspection.
文摘Mg and its alloys are suitable choices for implant materials due to their biodegradability and biocompatibility features. However, the high electrochemical activity of this family of biomaterials results in their fast degradation and severe corrosion in the physiological environment,producing hydrogen(H;) gas, and therefore increasing the p H of the environment. To meet the clinical requirements, the degradation rate of Mg biomaterials needs to be reduced. Nevertheless, higher corrosion resistance of Mg results in a low alkaline p H, weakening the antibacterial activity. Therefore, while the rapid degradation problem of Mg-based biomaterials needs to be addressed, good antibacterial properties are also necessary. By using the plasma electrolytic oxidation(PEO) surface modification technique, the antibacterial activity of Mg and its alloys can be enhanced while maintaining their corrosion protection properties at a high level. Throughout the PEO process, introducing antibacterial agents into solutions results in a major increase in antibacterial activity of the coatings. Moreover, post-or pre-processing on PEO coatings can provide better protection against bacteria. In this review, the antibacterial activity of PEO coatings applied on Mg and also its alloys will be discussed in more detail.
文摘It is known that the consumption of bacteria such as lactobacilli and bifidobacteria has beneficial effects on human immune function. Most of them are Gram-positive bacteria, and there are few reports on Gram-negative bacteria. In this study, we evaluated the effects of intake of Gluconacetobacter hansenii GK-1 (GK-1), Gram-negative acetic acid bacteria, for 12 weeks on physical condition and immune indices. We conducted a randomized, double-blind, placebo-controlled, parallel-group study in 100 healthy adults. The subjects were randomized into the GK-1 and the placebo groups. The diary-administered physical condition survey was conducted during the study period. The evaluation of salivary sIgA levels, NK-cell activity, and serum IFN-γ levels and quality of life survey was conducted before, in 6 weeks, and 12 weeks after the start of ingestion. Based on the physical condition survey, the cumulative onset-days of symptoms were significantly suppressed in the GK-1 group compared to the placebo group regarding the evaluation of 13 symptoms related to immunity, every 3 weeks. Additionally, salivary sIgA levels per hour were significantly increased in the GK-1 group compared with the placebo group at 6 and 12 weeks. Despite no significant differences in the NK-cell activity, serum IFN-γ levels or quality of life survey between the groups. Serum IFN-γ levels in the GK-1 group were significantly elevated at 12 weeks after the start of ingestion compared with those before ingestion. In conclusion, intake of GK-1 was shown to increase salivary sIgA levels and improve physical condition. This suggested that oral intake of GK-1 may help maintain the immune system.
文摘The study is to identify trends and levels of antibiotic resistance of some common Gram-negative strains over time. The samples were collected from Vietnam Military Hospital 103 between 2014 and 2019. A total of 405 <i>Acinetobacter baumannii</i>., 528 <i>Pseudomonas aeruginosa</i>, 741 <i>Escherichia coli</i>, and 352 <i>Klebsiella pneumoniae</i> strains were identified and antimicrobial susceptibility was by Vitek system and Etest method. The multi-drug resistance (MDR) was major proportion of four common bacteria. In particular, there is a tendency to shift from MDR to Extended drug resistance (XDR) or possibly Pan drug resistant (pPDR). <i>A. baumannii</i> had the highest level of antibiotic resistance, namely, carbapenem (61.5% - 82.5%) and cephalosporin (72.7% - 88.7%). <i>P. aeruginosa</i> resisted most of commonly antibiotics, ranging from 50% to 70%. <i>E. coli</i> had a high resistance with antibiotics like ampicillin (87.2% - 97.6%) and the 3rd generation cephalosporins (up to 79.6%). <i>K. pneumoniae</i> resisted carbapenem from 14.7% to 44.4%, and other antibiotics with the higher rate of 40%. The collected data will be a prerequisite for further studies on mechanisms and factors related to antibiotic resistant bacteria, in order to find out a rational and effective using strategy of antibiotics.
基金supported by Special Foundation for National Science and Technology Basic Research Program of China[2019FY101200]Beijing Key Clinical Specialty for Laboratory Medicine-Excellent Project[ZK201000].
文摘Objective To investigate the distribution and antimicrobial susceptibility of causative microorganisms recovered from patients with intra-abdominal infections(IAIs).Methods A total of 2,926 bacterial and fungal strains were identified in samples collected from 1,679 patients with IAIs at the Peking Union Medical College Hospital between 2011 and 2021.Pathogenic bacteria and fungi were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.Antimicrobial susceptibility testing(AST)was performed using the VITEK 2 compact system and the Kirby–Bauer method.AST results were interpreted based on the M100-Ed31 clinical breakpoints of the Clinical and Laboratory Standards Institute.Results Of the 2,926 strains identified,49.2%,40.8%,and 9.5%were gram-negative bacteria,gram-positive bacteria,and fungi,respectively.Escherichia coli was the most prevalent pathogen in intensive care unit(ICU)and non-ICU patients;however,a significant decrease was observed in the isolation of E.coli between 2011 and 2021.Specifically,significant decreases were observed between 2011 and 2021 in the levels of extended-spectrumβ-lactamase(ESBL)-producing E.coli(from 76.9%to 14.3%)and Klebsiella pneumoniae(from 45.8%to 4.8%).Polymicrobial infections,particularly those involving co-infection with gram-positive and gram-negative bacteria,were commonly observed in IAI patients.Moreover,Candida albicans was more commonly isolated from hospital-associated IAI samples,while Staphylococcus epidermidis had a higher ratio in community-associated IAIs.Additionally,AST results revealed that most antimicrobial agents performed better in non-ESBL-producers than in ESBL-producers,while the overall resistance rates(56.9%–76.8%)of Acinetobacter baumanmii were higher against all antimicrobial agents than those of other common gram-negative bacteria.Indeed,Enterococcus faecium,Enterococcus faecalis,S.epidermidis,and S.aureus were consistently found to be susceptible to vancomycin,teicoplanin,and linezolid.Similarly,C.albicans exhibited high susceptibility to all the tested antifungal drugs.Conclusion The distribution and antimicrobial susceptibility of the causative microorganisms from patients with IAls were altered between 2011 and 2021.This finding is valuable for the implementation of evidence-based antimicrobial therapy and provides guidance for the control of hospital infections.
基金supported by National Natural Science Foundation of China (NSFC, Nos. 91956105, 22077028 and 32000995)China National Postdoctoral Program for Innovative Talents(No. BX20200124)+2 种基金China Postdoctoral Science Foundation (No.2020M682544)the Fundamental Research Funds for the Central University (No. 531118010440)Major Research Projects (No.531118100003) from Hunan University。
文摘Infectious diseases become one of the leading causes of human death. Traditional treatment based on classical antibiotics could not provide enough antibacterial activity to combat bacterial infections due to low bioavailability, even leading to antibiotic resistance. In recent years, biomimetic delivery systems have been developed to improve drug therapy for various diseases, such as malignant tumor and cardiovascular disease. In this work, we designed virus-inspired nanodrugs(VNDs) through co-assembly of amphiphilic lipopeptide dendrons and poly(lactic-co-glycolic acid) polymers for high-efficiency antibiotic delivery. These VNDs had well-defined and stable nanostructures for tetracycline encapsulation and delivery. The VNDs were capable of promoting antibiotic internalization and enhancing their antibacterial effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Additionally, no obvious cytotoxicity of VNDs was observed to human cell lines. This work successfully demonstrated the virus-mimetic nanoparticles served as promising and applicable antibiotic delivery platform for antibacterial treatment.
文摘BACKGROUND Diabetic foot ulceration(DFU)is the prime health concern globally.It accounts for the major burden related to disease mortality and morbidity and economic cost.The timely and early recognition of the DFU can help present its occurrence and improve clinical outcomes.AIM To evaluate interrelationships between foot ulcers,risk factors,and antibiotic resistance among diabetic patients having ulcers in their foot.METHODS The databases such as PubMed,ERIC,Medline,and Google Scholar were extensively used for the extraction of studies.The selected studies were published within the time-period of 2014-2018.Ten studies were selected,which were found to be completely relevant to the current study.RESULTS The prevalence of diabetic foot ulcers among the population was evaluated,and the associated risk factors with its prevalence.Moreover,few studies also reported on the bacteria that are found to be most prevailing among diabetic patients.A narrative discussion was drawn through this analysis,which was used to highlight the specific area of research through selected studies,extraction of the significant information that matched with the topic of research,and analysis of problem through the findings of the selected articles.The results helped in assessing significant knowledge regarding the risk factors of diabetic foot ulcers and the role of antimicrobial resistant in its treatment.CONCLUSION The gram-negative bacteria were found to be the most common reason for diabetic foot ulcers.The study only included 10 studies that are not sufficient to produce generalized results,and no information was reported on the tests required to analyze antimicrobial susceptibility that can guide clinicians to propose better and sound treatment plans.It is evident that most study results depicted that the most common risk factors were found to be hypertension and neuropathy.
文摘<b>Introduction:</b> Oral cancer is the third most prominent type of cancer in Bangladesh. During or after oral cancer treatment, immune-compromised cancer patients may be susceptible to an infection by multi-drug-resistant opportunistic microbes. This study aims to identify the prevalent microorganisms from the infected site of oral cancer patients and observe their antibiotic susceptibility pattern. <b>Materials and Methods:</b> Clinical samples were collected from the infected sites of oral cancer patients and healthy people. The swabs collected were placed on nutrient agar slant, then incubated for 24 hours at 37ºC. Bacteria from the slant were inoculated in several selective media (Mannitol Salt Agar Media, KF Streptococcus Agar media, Cetrimide Agar, Eosin Methylene Blue Agar). Several biochemical tests identified opportunistic microorganisms. Finally, the antibiotic susceptibility test was performed by the Kirby Bauer disc diffusion method. <b>Results:</b> The study found that 65.4% of microbes isolated from the patients’ oral cavities were Gram-negative bacteria, and 34.6% were Gram-positive bacteria. Among the patient group isolates (n = 55), the most prevalent organism was <i>Pseudomonas</i> spp. (30;54.54%). Others were <i>Klebsiella</i> spp. (27;49.09%), <i>Staphylococcus</i> spp. (24;43.63%), <i>E. coli</i> (14;25.45%), <i>Streptococcus</i> spp. (14;25.45%), <i>Proteus</i> spp. (12;21.8%) and <i>Enterococcus</i> spp. (6;10.90%). Both Gram-positive and Gram-negative microbes from the patient group have shown high resistance to the commonly used antibiotics. In the control group (n = 50), the most prevalent organism was <i>Staphylococcus</i> spp. (15;30%). Other organisms were <i>Streptococcus</i> spp. (6;12%), <i>Klebsiella</i> spp. (11;22%), <i>E. coli</i> (3;6%), <i>Streptococcus</i> spp. (14;25.45%), <i>Pseudomonas</i> spp. (8;16%). The microbes of the control group showed less resistance to the antibiotics and rather showed sensitivity to them. <b>Conclusion:</b> The study revealed a high prevalence of multi-drug-resistant opportunistic microbes on immune-compromised oral cancer patients compared to microbes isolated from healthy people’s oral cavity.
文摘Rationale:Infectious keratopathy is an ocular emergency with the potential to cause irreversible blindness.Patient's concerns:A 63-year-old diabetic man presented with a 3-day history of painful red right eye.He had a history of multiple ocular surgeries in the affected eye without recent ocular trauma.Diagnosis:Infective crystalline keratopathy secondary to Citrobacter koseri.Interventions:Topical corticosteroids were discontinued,and dual topical antibiotic therapy of moxifloxacin 5%and gentamycin 0.3%were applied.Outcomes:Twelve hours after the start of treatment,the crystalline nature of the infiltrate disappeared,with enlargement of the epithelial defect.The antibiotic regime was continued and the lesion healed within a week of presentation with residual scarring.Lessons:Infective crystalline keratopathy classically presents with intrastromal branching fern-like opacities and minimal anterior segment inflammation in an immunosuppressed eye.The mainstay of management is corticosteroid discontinuation and the administration of empirical antibiotics until the results of the culture and sensitivity are available.In Citrobacter-related cases,treatment may result in a suppurative appearance before healing of the lesion.
基金Supported by Sichuan Youth Science and Technology Innovation Research Team of Experimental Formulology(No.2020JDTD0022)Chengdu University of Traditional Chinese Medicine"Xinglin Scholar"Scientific Research Promotion Program for Talents(No.XSGG2019006)Youth Talent Promotion Project of China Association for Science and Technology(No.CACM-2020-QNRC1-01)。
文摘OBJECTIVE:To investigate the anti-bacterial and anti-viral effects of Fengreqing oral liquid(风热清口服液,FRQ)in vitro and in vivo.METHODS:The minimum inhibitory concentrations of Fengreqing Oral Liquid against six gram-positive bacteria(Staphylococcus aureus,Streptococcus mutans,Peptostreptococcus anaerobius,Hemolytic streptococcus,Streptococcus pneumoniae,Klebsiella pneumoniae),seven gram-negative bacteria(Escherichia coli,Actinobacillus actinomycetemcomitans,Porphyromonas gingivalis,Haemophilus influenzae,Helicobacter pylori,Pseudomonas aeruginosa,Gardnerella vaginalis)and Candida albicans were detected by the paper disc diffusion method.The inhibition rate of A/Puerto Rico/8/34(H1N1)(PR8)influenza virus in different concentrations of Fengreqing oral solution was detected by chicken embryo method.CCK8 method was used to detect the half-cell infection of RSV,VSV and CVB3.The effect of FRQ on the survival curve of mice was detected by using co-infection model of Streptococcus pneumoniae and influenza virus.RESULTS:In vitro,FRQ can inhibit Actinobacillus actinomycetemcomitans,Helicobacter pylori,Gardnerella vaginalis,Staphylococcus aureus,Streptococcus mutans and Streptococcus pneumoniae and has an antiviral effect on the envelope virus H1N1.In vivo,Fengreqing oral solution had therapeutic effect on influenza-Streptococcus pneumoniae co-infection in mice,significantly improving the survival rate of mice.The medium dose and low dose FRQ significantly prolonged the survival time of mice.CONCLUSION:FRQ has good anti-bacterial and anti-viral effects in vivo and in vitro.
文摘Objective:To estimate the fatty acids content in the brown algae Padina pavonica(P.pavonica)and Hormophysa triquetra(H.triquetra)and evaluate their potential antimicrobial activity as bioactive compounds.Methods:The fatty acid compositions of the examined species were analyzed using gas chromatography-mass spectrometry.The antimicrobial activity of crude and fatty acids was assessed using the agar plug technique.Results:The fatty acids profile ranged from C8:0 to C20:4.Concentration of saturated fatty acids in P.pavonica was in the order palmitic>myristic>stearic whereas concentration of the unsaturated fatty acids was oleic acid>palmitoleic>9-cis-hexadecenoic>linoleic acid>α-linolenic>arachidonic>elaidic acid.H.triquetra contained high concentration of saturated fatty acids than those of P.pavonica which was in the order as follows:palmitic>margaric>myristic>nonadecyclic>stearic>caprylic>tridecylic>pentadecylic>lauric while the unsaturated fatty acids consisted of oleic>nonadecenoic>non adecadienoate>margaroleic.The crude and fatty acid extracts of H.triquetra and P.pavonica were biologically active on the tested pathogens.H.triquetra exhibited a larger inhibitory zone than P.pavonica.Conclusions:The brown algae P.pavonica and H.triquetra have high efficient amount of fatty acids and showed strong antibacterial activity,especially H.triquetra.
基金supported by grants from the Natural Science Foundation of China(81830049,92269202),National Key R&D Program(2022YFC2304700,2022YFC2303200,2018YFA0507300)Strategic Priority Research Program(XDB29030303)and International Partnership Program(153831KYSB20190008)of the Chinese Academy of Sciences,Shanghai Municipal Science and Technology Major Project(2019SHZDZX02)and Research Leader Program(20XD1403900),as well as the Innovation Capacity Building Project of Jiangsu Province(BM2020019).
文摘The innate immune responses,including inflammasome activation,are paramount for host defense against pathogen infection.In contrast to canonical and noncanonical inflammasome activation,in this study,heat-killed gram-negative bacteria(HK bacteria)were identified as single-step stimulators of the NLRP3 inflammasome in human monocytes,and they caused a moderate amount of IL-1βto be released from cells.Time course experiments showed that this alternative inflammasome response was finished within a few hours.Further analysis showed that the intrinsically limited NLRP3 inflammasome activation response was due to the negative regulation of caspase-8 by the short isoform of cFLIP(cFLIPs),which was activated by NF-κB.In contrast,overexpressed cFLIPS,but not overexpressed cFLIPL,inhibited the activation of caspase-8 and the release of IL-1βin response to HK bacteria infection in human monocytes.Furthermore,we demonstrated that TAK1 activity mediated the expression of cFLIPs and was upstream and essential for the caspase-8 cleavage induced by HK bacteria in human monocytes.The functional specificity of cFLIPs and TAK1 revealed unique responses of human monocytes to a noninvasive pathogen,providing novel insights into an alternative regulatory pathway of NLRP3 inflammasome activation.
基金from the National Key Research and Development Program of China(no.2017YFA0505200)the National Natural Science Foundation of China Grant(nos.21625201,21961142010,21661140001,91853202,and 21521003)+1 种基金the Beijing Outstanding Young Scientist Program(no.BJJWZYJH01201910001001)a special research grant for early drug discovery from Roche Pharma Research&Early Development is gratefully acknowledged.
文摘The rise of resistance to all known antibiotics is a global crisis.In addition to novel treatment options,there is an urgent need to develop rapid,specific,sensitive,and reliable diagnostic methods to detect pathogenic bacteria in clinical samples and reduce the overuse and misuse antibiotics.Pseudopaline,a metallophore produced by the human pathogen Pseudomonas aeruginosa,transports divalent metal ions via a dedicated active transport system,making it an ideal carrier for a second functional moiety.
