Objective:To investigate the in vitro interference of cefotaxime at subinhibitory concentrations [sub-minimal inhibitory concentrations(MIC)] on biofilm formation by nontypeable Haemophilus influenzae(NTHi).Methods:Th...Objective:To investigate the in vitro interference of cefotaxime at subinhibitory concentrations [sub-minimal inhibitory concentrations(MIC)] on biofilm formation by nontypeable Haemophilus influenzae(NTHi).Methods:The interference of subinhibitory concentrations of cefotaxime on biofilm formation of the clinical strong-biofilm forming isolates of NTHi was evaluated by a microtiter plate biofilm formation assay.The effect of sub-MIC cefotaxime on bacterial cell-surface hydrophobicity was determined using a standard microbial adhesion to n-hexadecane test.Additionally,the effects on bacterial adherence to human fibronectin and expression of bacterial adhesins were also investigated.Results:Subinhibitory concentrations of cefotaxime,both at 0.1× and 0.5× MIC levels,efficiently reduced the NTHi biofilm formation,and this effect was independent of decreasing bacterial viability.Sub-MIC cefotaxime also decreased bacterial cell-surface hydrophobicity and reduced adherence to human fibronectin.Inhibition in the P2 and P6 gene expressions upon exposure to sub-MIC cefotaxime was also noted.Conclusions:Taken together,our results indicate that sub-MIC cefotaxime interferes with the formation of NTHi biofilm,and this effect is feasibly related to the interference with cell-surface hydrophobicity,fibronectin-binding activity as well as alteration of the P2 and P6 gene expression.The findings of the present study therefore provide a rationale for the use of subinhibitory concentrations of cefotaxime for treatment of NTHi-related diseases.展开更多
Haemophilus parasuis (H. parasuis) is one of the bacterial pathogens of great concern as it causes huge economic losses to the swine industry worldwide. One of the reasons why the control of H. parasuis has failed is ...Haemophilus parasuis (H. parasuis) is one of the bacterial pathogens of great concern as it causes huge economic losses to the swine industry worldwide. One of the reasons why the control of H. parasuis has failed is the increase in antimicrobial resistance (AMR). The country of Vietnam has the second-largest pig production in Asia. However, there is still a lack of data about the AMR prevalence of H. parasuis in Vietnam.The purpose of this study is to investigate the prevalence of AMR and analyze the association between AMR and AMR genes (ARGs). The H. parasuis strains used in this research were isolated from swine in the Quang Binh and Thua Thien Hue Provinces, Central Vietnam, as reported in our previous study. All of the strains were tested for AMR against 25 antibacterial agents using the broth microdilution method and for the presence of ARGs using the polymerase chain reaction (PCR) method. The tested strains were shown to have a high frequency of resistance to trimethoprim/sulfamethoxazole (94.6%), followed by resistance to colistin, chloramphenicol, gentamicin, penicillin, lincomycin, and amoxicillin. The most prevalent ARGs in these strains were blaTEM-1 (94.6%), int (76.8%), gyrA (58.9%), and rmtD (50.0%). Cefuroxime, chloramphenicol, and tobramycin resistances were strongly correlated with the presence of the ARGs blaROB-1 (odds ratio (OR) = 26.3, 95% confidence interval (CI) 2.7–255.7, p = 0.002), catl (OR = 25.1, 95% CI 2.4–258.9, p = 0.004), and strB (OR = 23.5, 95% CI 2.6–212.6, p = 0.001), respectively.This study reveals for the first time the current situation of H. parasuis AMR in Central Vietnam, which is helpful for the clinical control of this disease, as well as for the development of policies and clinical practice guidelines to reduce AMR in swine production in Central Vietnam.展开更多
Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that...Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that provoke weight loss in animals or death. In the PRDC multiple pathogens (bacteria and/or viruses) work in combination to induce this respiratory disease. Within this complex, Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae are the main bacterial pathogens involved in great economic losses to the swine industry. The aim of this work was to estimate the presence of A. pleuropneumoniae, S. suis, P. multocida, B. bronchiseptica, H. parasuis and M. hyopneumoniae in the upper respiratory tract of pigs in representative swine farms inAguascalientes,Mexico, using PCR technique. The study was performed in 14 swine farms. We obtained a total of 212 nasal swabs. Near 20% of samples were positive for A. pleuropneumoniae (located in the 79% of farms);17% were positive for S. suis (in 86% of farms), of these, 3% were S. suis serovar 2;30% were positive for H. parasuis (93% of farms);23% of the samples to P. multocida (in 79% of farms);and 19% to M. hyopneumoniae (in 64% of farms). B. bronchiseptica was not detected in this study. The results obtained show that bacterial pathogens of PRDC were present in the upper respiratory tract of pigs in all farms studied;therefore, these pathogens are widely disseminated in pig farms of Aguascalientes, Mexico.展开更多
OBJECTIVE To develop a 2-week cigarette smoke(CS)acute lung injury model exacerbated by haemophilus influenzae(NTHi)and study the protective effect of andrographolide in this COPD model.METHODS Female BALB/c mice,6-8-...OBJECTIVE To develop a 2-week cigarette smoke(CS)acute lung injury model exacerbated by haemophilus influenzae(NTHi)and study the protective effect of andrographolide in this COPD model.METHODS Female BALB/c mice,6-8-week-old,were exposed to 4% 3R4 FCS delivered using aperistaltic pump daily for 2 weeks to induce an acute lung injury model.After 2 weeks of smoking,mice were inoculated intratracheally with NTHi to induce exacerbation on the model.Mice were sacrificed 48 h after last bacteria challenge and lung samples were collected for various analyses.RESULTS After developing a 2-week CS acute lung injury model exacerbated by NTHi,the CS+NTHi group was shown to have a higher inflammatory response,higher bacterial clearance,an upregulation of MMP12 mRNA levels and decrease in TIMP1 mRNA levels in the lungs.Administration of Andrographolide suppressed BALF lung cellular infiltrates,TNF-α,CXCL1/KC,IL-1βand 8-OHdG protein levels,together with increased HO-1 and GR mRNA levels and decreased MMP-8 and MMP-9 mRNA levels.Andrographolide was able to ameliorate lung histopathology as observed with H&E staining and inflammation scoring.Andrographolide was also shown to reduce Keap-1 level in lungs without affecting DJ-1 level.CONCLUSION This study demonstrates the protective effect of andrographolide in a novel 2-week CS acute lung injury model exacerbated by NTHi and presents it as a potential therapeutic for COPD.展开更多
To construct the suicide vector of hhd B gene marker-free mutant in Haemophilus parasuis( HPS),two pairs of specific primers were designed and synthesized according to the hhd B gene upstream and downstream sequences ...To construct the suicide vector of hhd B gene marker-free mutant in Haemophilus parasuis( HPS),two pairs of specific primers were designed and synthesized according to the hhd B gene upstream and downstream sequences of HPS published in Gen Bank. The hhd B gene upstream and downstream sequences were amplified by PCR,which were further ligated( hhd B-up + down) through overlapping PCR method. NotⅠand SalⅠrestriction enzyme sites were introduced on both ends of the ligated sequence. After the corresponding digestion,the hhd B-up + down sequence was directionally cloned to the suicide plasmid vector p EMOC2. Results showed that the suicide vector of hhd B gene marker-free deleted( p EMOC2Δhhd B) with stable inheritance in E. coli β2155 strain was successfully obtained,thereby laying the foundation for construction of HPS-hhd B gene marker-free mutant strain.展开更多
Objective:To study the molecular mechanisms of β-lactamase production in ampicillin resistant(AmP ) Hae- mophilus influenzae(HI). Methods: Identified the β-lactamases production strain from AmP HI was isolated from ...Objective:To study the molecular mechanisms of β-lactamase production in ampicillin resistant(AmP ) Hae- mophilus influenzae(HI). Methods: Identified the β-lactamases production strain from AmP HI was isolated from clinical cases with K-B method. β-lactamase encoding gene in enzyme production strains were detected by PCR with lactamase gene specific primers, and both plasmid and chromosomal DNA samples. Results: Thirty-two out of 36 (88 .9% ) were found to be β-lactamase production. Twenty-nine out of 32 enzyme production stain were PCR positive (the ratio of PCR positives 90.6% ). There were 25 stains amplified with plasmid DNA positively, and 4 with chromosomal DNA. Conclusion: (l ) Most of the AmPr HI strain produce lactamase is mediated by plasmid. (2) Detection of lactamase encoding gene in HI is a simple and efficient approach to study the molecular basis of ampicillin resistance.展开更多
BACKGROUND Haemophilus parainfluenzae(HPI)belongs to the HACEK(Haemophilus spp.,Aggregatibacter spp.,Cardiobacterium spp.,Eikenella spp.,and Kingella spp.)group of organisms.The HACEK group of organisms are a part of ...BACKGROUND Haemophilus parainfluenzae(HPI)belongs to the HACEK(Haemophilus spp.,Aggregatibacter spp.,Cardiobacterium spp.,Eikenella spp.,and Kingella spp.)group of organisms.The HACEK group of organisms are a part of the oropharyngeal flora and can cause invasive opportunistic infection such infective endocarditis(IE)in hosts with compromised immunological barriers.AIM To perform a 20-year systematic review of the literature characterizing the clinical presentation,epidemiology and prognosis of HPI IE.METHODS We performed a systematic review of Medline,Pubmed,Scopus and Embase from 2000 to 2022 to identify all cases of HPI IE.RESULTS Thirty-nine adult cases were identified.HPI IE was found to affect males slightly more than females and is common in patients with predisposing risk factors such as underlying valvular abnormalities.It mostly affected the mitral valve and had an indolent course;significantly sized vegetations(>1 cm)developed in most cases.Central nervous system septic embolization was common.It had a favorable prognosis compared to staphylococcal and streptococcal IE.CONCLUSION Clinicians should be attentive to the indolent course of HPI IE and the presence of predisposing risk factors in order to allow for timely management.展开更多
Haemophilus influenzae is an important pathogen that caused several infection diseases, such as sinusitis, otitis media, sepsis, and meningitis. This study was conducted to find out the prevalence and antimicrobial su...Haemophilus influenzae is an important pathogen that caused several infection diseases, such as sinusitis, otitis media, sepsis, and meningitis. This study was conducted to find out the prevalence and antimicrobial susceptibility pattern of Haemophilus influenzae isolates at general hospital in the central region of Japan from December 2015 to January 2016. Haemophilus influenzae was identified by standard laboratory procedure. Antimicrobial susceptibility testing was performed by micro dilution assay according to CLSI recommendation. One hundred ninety-one Haemophilus influenzae were isolated, among which 95 (49.7%) were from male and 96 (50.3%) were from female. The age incidence of (0) years, (≤2) years, (≤5) years, and (6≤) years groups were 22(11.5%), 92(48.2%), 61(31.9%), and 16(8.4%), respectively. Positive samples were received mostly from the nasal discharge (177/92.7%), sputum (6/3.1%), tonsillar (6/3.1%), and pharynx (2/1.0%). Ceftriaxone was the most active antibiotics with 100% susceptible rates, followed by ciprofloxacin (99.5%) and minocycline (99%) in our study. Furthermore, we categorized four patterns: beta lactamase-negative ampicillin-sensitive strain (BLNAS), beta lactamase-negative ampicillin-re- sistant strain (BLNAR), beta lactamase-positive ampicillin resistant strain (BLPAR), and beta lactamase-positive amoxicillin-clavulanic acid-resistant strain (BLPACR) from those ampicillin susceptible results. The numbers of female were significant greater than those of male in BLPAR (p = 0.0336). With respect to antimicrobial susceptible pattern, there was no minocycline and piperacillin resistant strain in both BLNAS and BLNAR (p展开更多
Introduction:Haemophilus influenzae(Hi)is subdivided into typeable(a-f)and non-typeable groups.Hi serotype b(Hib)has historically been one of the important pathogens responsible for invasive infection.However,after wi...Introduction:Haemophilus influenzae(Hi)is subdivided into typeable(a-f)and non-typeable groups.Hi serotype b(Hib)has historically been one of the important pathogens responsible for invasive infection.However,after widespread Hib vaccination,the emergence of other Hi serotypes,specifically Hi serotype a(Hia),was noted during the last few decades,mostly in children younger than 5 years of age.Case presentation:We present two cases of severe intracranial infections with detected Hia in patients>5 years of age within a short time frame and within the same geographic area.Conclusion:Epidemiological studies and surveillance on Hia-related illnesses in all age groups worldwide are needed to better understand the clinical and epidemiological characteristics of Hia.This can establish a platform to develop a candidate vaccine against Hia that might protect children of all ages.展开更多
Importance:In remote communities of the Northern Territory,Australia,children experience high rates of otitis media(OM),commonly caused by non-typeable Haemophilus influenzae(NTHi).Few data exist on antibiotic suscept...Importance:In remote communities of the Northern Territory,Australia,children experience high rates of otitis media(OM),commonly caused by non-typeable Haemophilus influenzae(NTHi).Few data exist on antibiotic susceptibility of NTHi from OM.Objective:To determine whether population-level nasopharyngeal NTHi antibiotic susceptibility data could inform antibiotic treatment for OM.Methods:NTHi isolates(n=92)collected from ear discharge between 2003 and 2013 were selected to time-and age-match NTHi isolates from the nasopharyngeal carriage(n=95).Antimicrobial susceptibility were tested.Phylogenomic trees and a genome-wide association study(GWAS)were performed to determine the similarity of nasopharyngeal and ear isolates at a population level.Results:Among 174 NTHi isolates available for antimicrobial susceptibility testing,10.3%(18/174)were resistant to ampicillin and 9.2%(16/174)were resistant to trimethoprim-sulfamethoxazole.Small numbers of isolates(≤3)were resistant to tetracycline,chloramphenicol,or amoxicillin-clavulanic acid.There was no statistical difference in the proportion of ampicillin-resistant(P=0.11)or trimethoprim-sulfamethoxazole-resistant isolates(P=0.70)between ear discharge and nasopharynx-derived NTHi isolates.Three multi-drug resistant NTHi isolates were identified.Phylogenomic trees showed no clustering of 187 Haemophilus influenzae isolates based on anatomical niche(nasopharynx or ear discharge),and no genetic variations that distinguished NTHi derived from ear discharge and nasopharyngeal carriage were evident in the GWAS.Interpretation:In this population-level study,nasopharyngeal and ear discharge isolates did not represent distinct microbial populations.These results support tracking of population-level nasopharyngeal NTHi antibiotic resistance patterns to inform clinical management of OM in this population.展开更多
The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(...The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard was developed for simultaneous determination of ribose and phosphorus contents in Hib CPS.Hexamethylphosphoramide(HMPA)was successfully utilized as an internal standard in quantitative ^(1)H-NMR method for ribose content determination.The ribose and phosphorus contents were found to be affected by the concentration of polysaccharide solution.Thus,15–20 mg·L^(−1) was the optimal concentration range of Hib CPS in D_(2)O solution for determination of ribose and phosphorus contents by this method.The ribose and phosphorus contents obtained by the quantitative NMR were consistent with those obtained by traditional chemical methods.In conclusion,this quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard shows good specificity,accuracy and precision,providing a valuable approach for the quality control of Hib glycoconjugate vaccines.展开更多
针对副猪嗜血杆菌(Haemophilus parasuis,HPS)16 S rRNA序列设计1对特异性引物,能扩增出821 bp的特异性DNA片段,并据此建立了快速准确鉴定副猪嗜血杆菌PCR方法,临床试验证明该方法具有很好的特异性和敏感性。13份疑似病料检测结果表明,...针对副猪嗜血杆菌(Haemophilus parasuis,HPS)16 S rRNA序列设计1对特异性引物,能扩增出821 bp的特异性DNA片段,并据此建立了快速准确鉴定副猪嗜血杆菌PCR方法,临床试验证明该方法具有很好的特异性和敏感性。13份疑似病料检测结果表明,PCR检测结果与传统生化鉴定结果符合率为100%。结果表明已成功建立了副猪嗜血杆菌PCR检测方法,并可应用于临床副猪嗜血杆菌的检测。展开更多
AIM:To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene tran-scription. METHODS:Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus ...AIM:To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene tran-scription. METHODS:Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus influenza and Escherichia coli infection was analyzed by employing quantitative Reverse Transcription Polymerase Chain Reaction techniques. Nucleofection was used to deliver Lenti-viral system to express or knock down Lpcat1 in MLE cells. Subcellular protein fractionation and Western blotting were utilized to study Lpcat1 nuclear relocation. RESULTS:Lpcat1 translocates into the nucleus from thecytoplasm in murine lung epithelia (MLE) after LPS treatment. Haemophilus influenza and Escherichia coli , two LPS-containing pathogens that cause pneumonia, triggered Lpcat1 nuclear translocation from the cytoplasm. The LPS inducible gene expression profile was determined by quantitative reverse transcription polymerase chain reaction after silencing Lpcat1 or overexpression of the enzyme in MLE cells. We detected that 17 out of a total 38 screened genes were upregulated, 14 genes were suppressed, and 7 genes remained unchanged in LPS treated cells in comparison to controls. Knockdown of Lpcat1 by shRNA dramatically changed the spectrum of the LPS inducible gene transcription, as 18 genes out of 38 genes were upregulated, of which 20 genes were suppressed or unchanged. Notably, in Lpcat1 overex-pressed cells, 25 genes out of 38 genes were reduced in the setting of LPS treatment.CONCLUSION:These observations suggest that Lpcat1 relocates into the nucleus in response to bacterial infection to differentially regulate gene transcriptional repression.展开更多
基金Supported by the National Research Council of Thailand through the Annual Research Fund of Naresuan University(Grant No.R2557B011)
文摘Objective:To investigate the in vitro interference of cefotaxime at subinhibitory concentrations [sub-minimal inhibitory concentrations(MIC)] on biofilm formation by nontypeable Haemophilus influenzae(NTHi).Methods:The interference of subinhibitory concentrations of cefotaxime on biofilm formation of the clinical strong-biofilm forming isolates of NTHi was evaluated by a microtiter plate biofilm formation assay.The effect of sub-MIC cefotaxime on bacterial cell-surface hydrophobicity was determined using a standard microbial adhesion to n-hexadecane test.Additionally,the effects on bacterial adherence to human fibronectin and expression of bacterial adhesins were also investigated.Results:Subinhibitory concentrations of cefotaxime,both at 0.1× and 0.5× MIC levels,efficiently reduced the NTHi biofilm formation,and this effect was independent of decreasing bacterial viability.Sub-MIC cefotaxime also decreased bacterial cell-surface hydrophobicity and reduced adherence to human fibronectin.Inhibition in the P2 and P6 gene expressions upon exposure to sub-MIC cefotaxime was also noted.Conclusions:Taken together,our results indicate that sub-MIC cefotaxime interferes with the formation of NTHi biofilm,and this effect is feasibly related to the interference with cell-surface hydrophobicity,fibronectin-binding activity as well as alteration of the P2 and P6 gene expression.The findings of the present study therefore provide a rationale for the use of subinhibitory concentrations of cefotaxime for treatment of NTHi-related diseases.
文摘Haemophilus parasuis (H. parasuis) is one of the bacterial pathogens of great concern as it causes huge economic losses to the swine industry worldwide. One of the reasons why the control of H. parasuis has failed is the increase in antimicrobial resistance (AMR). The country of Vietnam has the second-largest pig production in Asia. However, there is still a lack of data about the AMR prevalence of H. parasuis in Vietnam.The purpose of this study is to investigate the prevalence of AMR and analyze the association between AMR and AMR genes (ARGs). The H. parasuis strains used in this research were isolated from swine in the Quang Binh and Thua Thien Hue Provinces, Central Vietnam, as reported in our previous study. All of the strains were tested for AMR against 25 antibacterial agents using the broth microdilution method and for the presence of ARGs using the polymerase chain reaction (PCR) method. The tested strains were shown to have a high frequency of resistance to trimethoprim/sulfamethoxazole (94.6%), followed by resistance to colistin, chloramphenicol, gentamicin, penicillin, lincomycin, and amoxicillin. The most prevalent ARGs in these strains were blaTEM-1 (94.6%), int (76.8%), gyrA (58.9%), and rmtD (50.0%). Cefuroxime, chloramphenicol, and tobramycin resistances were strongly correlated with the presence of the ARGs blaROB-1 (odds ratio (OR) = 26.3, 95% confidence interval (CI) 2.7–255.7, p = 0.002), catl (OR = 25.1, 95% CI 2.4–258.9, p = 0.004), and strB (OR = 23.5, 95% CI 2.6–212.6, p = 0.001), respectively.This study reveals for the first time the current situation of H. parasuis AMR in Central Vietnam, which is helpful for the clinical control of this disease, as well as for the development of policies and clinical practice guidelines to reduce AMR in swine production in Central Vietnam.
文摘Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that provoke weight loss in animals or death. In the PRDC multiple pathogens (bacteria and/or viruses) work in combination to induce this respiratory disease. Within this complex, Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae are the main bacterial pathogens involved in great economic losses to the swine industry. The aim of this work was to estimate the presence of A. pleuropneumoniae, S. suis, P. multocida, B. bronchiseptica, H. parasuis and M. hyopneumoniae in the upper respiratory tract of pigs in representative swine farms inAguascalientes,Mexico, using PCR technique. The study was performed in 14 swine farms. We obtained a total of 212 nasal swabs. Near 20% of samples were positive for A. pleuropneumoniae (located in the 79% of farms);17% were positive for S. suis (in 86% of farms), of these, 3% were S. suis serovar 2;30% were positive for H. parasuis (93% of farms);23% of the samples to P. multocida (in 79% of farms);and 19% to M. hyopneumoniae (in 64% of farms). B. bronchiseptica was not detected in this study. The results obtained show that bacterial pathogens of PRDC were present in the upper respiratory tract of pigs in all farms studied;therefore, these pathogens are widely disseminated in pig farms of Aguascalientes, Mexico.
基金The project supported by National Medical Research Council(NMRC/CBRG/0027/2012)
文摘OBJECTIVE To develop a 2-week cigarette smoke(CS)acute lung injury model exacerbated by haemophilus influenzae(NTHi)and study the protective effect of andrographolide in this COPD model.METHODS Female BALB/c mice,6-8-week-old,were exposed to 4% 3R4 FCS delivered using aperistaltic pump daily for 2 weeks to induce an acute lung injury model.After 2 weeks of smoking,mice were inoculated intratracheally with NTHi to induce exacerbation on the model.Mice were sacrificed 48 h after last bacteria challenge and lung samples were collected for various analyses.RESULTS After developing a 2-week CS acute lung injury model exacerbated by NTHi,the CS+NTHi group was shown to have a higher inflammatory response,higher bacterial clearance,an upregulation of MMP12 mRNA levels and decrease in TIMP1 mRNA levels in the lungs.Administration of Andrographolide suppressed BALF lung cellular infiltrates,TNF-α,CXCL1/KC,IL-1βand 8-OHdG protein levels,together with increased HO-1 and GR mRNA levels and decreased MMP-8 and MMP-9 mRNA levels.Andrographolide was able to ameliorate lung histopathology as observed with H&E staining and inflammation scoring.Andrographolide was also shown to reduce Keap-1 level in lungs without affecting DJ-1 level.CONCLUSION This study demonstrates the protective effect of andrographolide in a novel 2-week CS acute lung injury model exacerbated by NTHi and presents it as a potential therapeutic for COPD.
基金Supported by Science and Technology Project of Guangdong Province(2013B020307002)
文摘To construct the suicide vector of hhd B gene marker-free mutant in Haemophilus parasuis( HPS),two pairs of specific primers were designed and synthesized according to the hhd B gene upstream and downstream sequences of HPS published in Gen Bank. The hhd B gene upstream and downstream sequences were amplified by PCR,which were further ligated( hhd B-up + down) through overlapping PCR method. NotⅠand SalⅠrestriction enzyme sites were introduced on both ends of the ligated sequence. After the corresponding digestion,the hhd B-up + down sequence was directionally cloned to the suicide plasmid vector p EMOC2. Results showed that the suicide vector of hhd B gene marker-free deleted( p EMOC2Δhhd B) with stable inheritance in E. coli β2155 strain was successfully obtained,thereby laying the foundation for construction of HPS-hhd B gene marker-free mutant strain.
文摘Objective:To study the molecular mechanisms of β-lactamase production in ampicillin resistant(AmP ) Hae- mophilus influenzae(HI). Methods: Identified the β-lactamases production strain from AmP HI was isolated from clinical cases with K-B method. β-lactamase encoding gene in enzyme production strains were detected by PCR with lactamase gene specific primers, and both plasmid and chromosomal DNA samples. Results: Thirty-two out of 36 (88 .9% ) were found to be β-lactamase production. Twenty-nine out of 32 enzyme production stain were PCR positive (the ratio of PCR positives 90.6% ). There were 25 stains amplified with plasmid DNA positively, and 4 with chromosomal DNA. Conclusion: (l ) Most of the AmPr HI strain produce lactamase is mediated by plasmid. (2) Detection of lactamase encoding gene in HI is a simple and efficient approach to study the molecular basis of ampicillin resistance.
文摘BACKGROUND Haemophilus parainfluenzae(HPI)belongs to the HACEK(Haemophilus spp.,Aggregatibacter spp.,Cardiobacterium spp.,Eikenella spp.,and Kingella spp.)group of organisms.The HACEK group of organisms are a part of the oropharyngeal flora and can cause invasive opportunistic infection such infective endocarditis(IE)in hosts with compromised immunological barriers.AIM To perform a 20-year systematic review of the literature characterizing the clinical presentation,epidemiology and prognosis of HPI IE.METHODS We performed a systematic review of Medline,Pubmed,Scopus and Embase from 2000 to 2022 to identify all cases of HPI IE.RESULTS Thirty-nine adult cases were identified.HPI IE was found to affect males slightly more than females and is common in patients with predisposing risk factors such as underlying valvular abnormalities.It mostly affected the mitral valve and had an indolent course;significantly sized vegetations(>1 cm)developed in most cases.Central nervous system septic embolization was common.It had a favorable prognosis compared to staphylococcal and streptococcal IE.CONCLUSION Clinicians should be attentive to the indolent course of HPI IE and the presence of predisposing risk factors in order to allow for timely management.
文摘Haemophilus influenzae is an important pathogen that caused several infection diseases, such as sinusitis, otitis media, sepsis, and meningitis. This study was conducted to find out the prevalence and antimicrobial susceptibility pattern of Haemophilus influenzae isolates at general hospital in the central region of Japan from December 2015 to January 2016. Haemophilus influenzae was identified by standard laboratory procedure. Antimicrobial susceptibility testing was performed by micro dilution assay according to CLSI recommendation. One hundred ninety-one Haemophilus influenzae were isolated, among which 95 (49.7%) were from male and 96 (50.3%) were from female. The age incidence of (0) years, (≤2) years, (≤5) years, and (6≤) years groups were 22(11.5%), 92(48.2%), 61(31.9%), and 16(8.4%), respectively. Positive samples were received mostly from the nasal discharge (177/92.7%), sputum (6/3.1%), tonsillar (6/3.1%), and pharynx (2/1.0%). Ceftriaxone was the most active antibiotics with 100% susceptible rates, followed by ciprofloxacin (99.5%) and minocycline (99%) in our study. Furthermore, we categorized four patterns: beta lactamase-negative ampicillin-sensitive strain (BLNAS), beta lactamase-negative ampicillin-re- sistant strain (BLNAR), beta lactamase-positive ampicillin resistant strain (BLPAR), and beta lactamase-positive amoxicillin-clavulanic acid-resistant strain (BLPACR) from those ampicillin susceptible results. The numbers of female were significant greater than those of male in BLPAR (p = 0.0336). With respect to antimicrobial susceptible pattern, there was no minocycline and piperacillin resistant strain in both BLNAS and BLNAR (p
文摘Introduction:Haemophilus influenzae(Hi)is subdivided into typeable(a-f)and non-typeable groups.Hi serotype b(Hib)has historically been one of the important pathogens responsible for invasive infection.However,after widespread Hib vaccination,the emergence of other Hi serotypes,specifically Hi serotype a(Hia),was noted during the last few decades,mostly in children younger than 5 years of age.Case presentation:We present two cases of severe intracranial infections with detected Hia in patients>5 years of age within a short time frame and within the same geographic area.Conclusion:Epidemiological studies and surveillance on Hia-related illnesses in all age groups worldwide are needed to better understand the clinical and epidemiological characteristics of Hia.This can establish a platform to develop a candidate vaccine against Hia that might protect children of all ages.
基金Centre of Research Excellence in Ear and Hearing Health of Aboriginal and Torres Strait Islander Children,National Health and Medical Research Council(CRE07)
文摘Importance:In remote communities of the Northern Territory,Australia,children experience high rates of otitis media(OM),commonly caused by non-typeable Haemophilus influenzae(NTHi).Few data exist on antibiotic susceptibility of NTHi from OM.Objective:To determine whether population-level nasopharyngeal NTHi antibiotic susceptibility data could inform antibiotic treatment for OM.Methods:NTHi isolates(n=92)collected from ear discharge between 2003 and 2013 were selected to time-and age-match NTHi isolates from the nasopharyngeal carriage(n=95).Antimicrobial susceptibility were tested.Phylogenomic trees and a genome-wide association study(GWAS)were performed to determine the similarity of nasopharyngeal and ear isolates at a population level.Results:Among 174 NTHi isolates available for antimicrobial susceptibility testing,10.3%(18/174)were resistant to ampicillin and 9.2%(16/174)were resistant to trimethoprim-sulfamethoxazole.Small numbers of isolates(≤3)were resistant to tetracycline,chloramphenicol,or amoxicillin-clavulanic acid.There was no statistical difference in the proportion of ampicillin-resistant(P=0.11)or trimethoprim-sulfamethoxazole-resistant isolates(P=0.70)between ear discharge and nasopharynx-derived NTHi isolates.Three multi-drug resistant NTHi isolates were identified.Phylogenomic trees showed no clustering of 187 Haemophilus influenzae isolates based on anatomical niche(nasopharynx or ear discharge),and no genetic variations that distinguished NTHi derived from ear discharge and nasopharyngeal carriage were evident in the GWAS.Interpretation:In this population-level study,nasopharyngeal and ear discharge isolates did not represent distinct microbial populations.These results support tracking of population-level nasopharyngeal NTHi antibiotic resistance patterns to inform clinical management of OM in this population.
基金supported by the National Natural Science Foundation of China(Nos.22077052,21877052,21907039 and 22107037)the China Postdoctoral Science Foundation(Nos.2020M681487 and 2021M691279)+4 种基金the National Key R&D Program of China(No.2020YFA0908304)the Natural Science Foundation of Jiangsu Province(Nos.BK20180030 and BK20190575)the National First-class Discipline Program of Light Industry Technology and Engineering(No.LITE2018-14)the 111 Project(No.111-2-06)the Open Project of Key Laboratory of Carbohydrate Chemistry and Biotechnology(Jiangnan University),Ministry of Education(No.KLCCB-KF202005)。
文摘The ribose and phosphorus contents in Haemophilus influenzae type b(Hib)capsular polysaccharide(CPS)are two important chemical indexes for the development and quality control of Hib conjugate vaccine.A quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard was developed for simultaneous determination of ribose and phosphorus contents in Hib CPS.Hexamethylphosphoramide(HMPA)was successfully utilized as an internal standard in quantitative ^(1)H-NMR method for ribose content determination.The ribose and phosphorus contents were found to be affected by the concentration of polysaccharide solution.Thus,15–20 mg·L^(−1) was the optimal concentration range of Hib CPS in D_(2)O solution for determination of ribose and phosphorus contents by this method.The ribose and phosphorus contents obtained by the quantitative NMR were consistent with those obtained by traditional chemical methods.In conclusion,this quantitative ^(1)H-and ^(31)P-NMR method using a single internal standard shows good specificity,accuracy and precision,providing a valuable approach for the quality control of Hib glycoconjugate vaccines.
文摘针对副猪嗜血杆菌(Haemophilus parasuis,HPS)16 S rRNA序列设计1对特异性引物,能扩增出821 bp的特异性DNA片段,并据此建立了快速准确鉴定副猪嗜血杆菌PCR方法,临床试验证明该方法具有很好的特异性和敏感性。13份疑似病料检测结果表明,PCR检测结果与传统生化鉴定结果符合率为100%。结果表明已成功建立了副猪嗜血杆菌PCR检测方法,并可应用于临床副猪嗜血杆菌的检测。
基金Supported by A United States National Institutes of Health R01 grant HL091916 to Zhao Yan American Heart Association grant 12SDG12040330 to Zou C, in part
文摘AIM:To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene tran-scription. METHODS:Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus influenza and Escherichia coli infection was analyzed by employing quantitative Reverse Transcription Polymerase Chain Reaction techniques. Nucleofection was used to deliver Lenti-viral system to express or knock down Lpcat1 in MLE cells. Subcellular protein fractionation and Western blotting were utilized to study Lpcat1 nuclear relocation. RESULTS:Lpcat1 translocates into the nucleus from thecytoplasm in murine lung epithelia (MLE) after LPS treatment. Haemophilus influenza and Escherichia coli , two LPS-containing pathogens that cause pneumonia, triggered Lpcat1 nuclear translocation from the cytoplasm. The LPS inducible gene expression profile was determined by quantitative reverse transcription polymerase chain reaction after silencing Lpcat1 or overexpression of the enzyme in MLE cells. We detected that 17 out of a total 38 screened genes were upregulated, 14 genes were suppressed, and 7 genes remained unchanged in LPS treated cells in comparison to controls. Knockdown of Lpcat1 by shRNA dramatically changed the spectrum of the LPS inducible gene transcription, as 18 genes out of 38 genes were upregulated, of which 20 genes were suppressed or unchanged. Notably, in Lpcat1 overex-pressed cells, 25 genes out of 38 genes were reduced in the setting of LPS treatment.CONCLUSION:These observations suggest that Lpcat1 relocates into the nucleus in response to bacterial infection to differentially regulate gene transcriptional repression.
