Pneumonia, the most typical and frequent lower respiratory tract infection （LRTI）, is a leading cause of health problems in the United States. Bacteria represent the most prevailing cause of pneumonia in both childr...Pneumonia, the most typical and frequent lower respiratory tract infection （LRTI）, is a leading cause of health problems in the United States. Bacteria represent the most prevailing cause of pneumonia in both children and adults. Although pneumonia with a single bacterial infection is common, a significant portion of patients with pneumonia is polymicrobial. This infection is often complexed with other physiological factors such as cytokines and growth factors. Nontypeable Haemophilus influenzae （NTHi） is the most frequently recovered Gram-negative bacterial pathogen in the respiratory system and induces strong inflammatory responses. NTHi also synergizes with other respiratory pathogens, such as Streptococcus pneumoniae and respiratory viruses and pro-inflammatory cytokines, such as tumor necrosis factor-alpha （TNF-α）. It is noteworthy that NTHi not only synergizes with growth factors such as transforming growth factor-beta （TGF-β）, but also utilizes growth factor receptors such as TGF-β receptor and epidermal growth factor receptor （EGFR）, to enhance inflammatory responses. Although appropriate inflammation is a protective response against invading pathogens, an uncontrolled inflammatory response is often detrimental to the host. Thus, inflammation must be tightly regulated. The human immune system has evolved strategies for controlling overactive inflammatory response. One such important mechanism is via regulation of negative feedback regulators for inflammation. CYLD, a multifunctional deubiquitinase, was originally reported as a tumor suppressor, but was recently identified as a negative regulator for nuclear factor-kappa B （NF-κB） signaling. It is induced by NTHi and TNF-α via a NF-κB-dependent mechanism, thereby serving as an inducible negative feedback regulator for tightly controlling inflammation in NTHi infection.展开更多
目的建立一种b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)结合疫苗中游离多糖含量新的检测方法。方法分别对标准蛋白溶液、多糖溶液和标加衍生多糖(AH-PRP)的结合物原液进行脱氧胆酸钠(NaDC)酸沉淀处理,观察该方法对蛋白和多...目的建立一种b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)结合疫苗中游离多糖含量新的检测方法。方法分别对标准蛋白溶液、多糖溶液和标加衍生多糖(AH-PRP)的结合物原液进行脱氧胆酸钠(NaDC)酸沉淀处理,观察该方法对蛋白和多糖的沉淀效果。分别采用NaDC酸沉淀法和乙醇分步沉淀法测定结合疫苗原液中的游离多糖含量。结果不同浓度的标准蛋白溶液经NaDC酸沉淀法处理后,沉淀中蛋白的回收率在96%～99%之间;不同浓度的多糖溶液经NaDC酸沉淀法处理后,上清中的多糖回收率在99%～106%之间;该方法对结合物中的游离多糖能起到很好的分离效果;两种方法测定结合疫苗原液中的游离多糖含量差异有统计学意义(P<0.01)。结论 NaDC酸沉淀法能专一性地沉淀蛋白物质,对游离多糖无沉淀作用,该方法具有良好的重复性和准确性,可用于测定Hib结合疫苗中的游离多糖含量。展开更多
HACEK organisms represent a rare but important group of causative pathogens in endocarditis. These bacteria have historically been associated with culture-negative endocarditis;however, modern laboratory techniques ha...HACEK organisms represent a rare but important group of causative pathogens in endocarditis. These bacteria have historically been associated with culture-negative endocarditis;however, modern laboratory techniques have made this less common. In this case, we present a 74-year-old man who presented with acute onset altered mentation, fever, and sepsis. He was ultimately found to have Haemophilus influenzae meningitis, cerebral empyema, aortic valve endocarditis, psoas myositis, and L2 - L3 diskitis with osteomyelitis. Although HACEK organisms are commonly found in the oropharynx and upper respiratory tract in humans, our patient did not report recent preceding dental or ENT procedures. H. influenzae is responsible for approximately 0.16% of all cases of bacterial endocarditis, representing a very limited subset. Although generally considered low virulent pathogens, this case demonstrates the unusual extent of infection from a HACEK organism, H. influenzae, causing aortic valve endocarditis as well as atypical non-cardiac sequelae, including acute meningitis.展开更多
Background It is recognized that Haemophilus influenzae isolated from patients with otitis media forms biofilms both in vitro and in vivo, suggesting that biofilm formation in vivo might play an important role in the ...Background It is recognized that Haemophilus influenzae isolated from patients with otitis media forms biofilms both in vitro and in vivo, suggesting that biofilm formation in vivo might play an important role in the pathogenesis and chronicity of otitis media, but the effect of antibiotics on biofilm has not been well studied. We investigated the impact of ciprofloxacin and azithromycin on bacterial biofilms formed by Haemophilus influenzae in vitro in this study. Methods Eleven strains of Haemophilus influenzae were isolated from sputum specimens collected from patients with acute exacerbation of chronic obstructive pulmonary diseases. Formation of bacterial biofUm was examined by crystal violet assay and a scanning electron microscope. Alterations of biofilms were measured under varying concentrations of azithromycin and ciprofloxacin. Results Striking differences were observed among strains with regard to the ability to form biofilm. Typical membrane-like structure formed by bacterial cells and extracellular matrix was detected. Initial biofilm synthesis was inhibited by azithromycin and ciprofloxacin at concentrations higher than two-fold minimal inhibitory concentration. Disruption of mature biofilms could be achieved at relatively higher concentration, and ciprofloxacin displayed more powerful activity. Conclusions Haemophilus influenzae is capable of forming biofilm in vitro. Sufficient dosage might control early formation of biofilms. Ciprofloxacin exerts better effects on breakdown of biofilm than azithromycin at conventional concentration in clinics.展开更多
Background Immunization is one of the most far-reaching and cost-effective strategies for promoting good health and saving lives.A complex immunization schedule,however,may be burdensome to parents and lead to reduced...Background Immunization is one of the most far-reaching and cost-effective strategies for promoting good health and saving lives.A complex immunization schedule,however,may be burdensome to parents and lead to reduced vaccine compliance and completion.Thus,it is critical to develop combination vaccines to reduce the number of injections and simplify the immunization schedule.This study aimed to investigate the current status of the pentavalent diphtheria-tetanus-acellular pertussis inactivated poliomyelitis andHaemophilus influenzae type B conjugate(DTaP-IPV/Hib)vaccination in Southern China as well as explore the factors in the general population associated with uptake and the differences between urban and rural populations.Methods A cross-sectional study was conducted with recently enrolled kindergarten students in Hainan Province between December 2022 and January 2023.The study employed a stratified multistage cluster random sampling method.Information regarding the demographic characteristics and factors that influence decisions were collected from the caregivers of children via an online questionnaire.Multivariate logistic regression was used to determine the factors associated with the status of DTap-IPV/Hib vaccinations.Results Of the 4818 valid responses,95.3%of children were aged 3-4 years,and 2856(59.3%)held ruralhukou.Coverage rates of the DTaP-IPV/Hib vaccine,from 1 to 4 doses,were 24.4%,20.7%,18.5%,and 16.0%,respectively.Caregivers who are concerned about vaccine efficacy[adjusted odds ratio(aOR)=1.53,95%confidence interval(CI):1.30-1.79],the manufacturer(aOR=2.05,95%CI:1.69-2.49),and a simple immunization schedule(aOR=1.26,95%CI:1.04-1.54)are factors associated with a higher likelihood of vaccinating children against DTaP-IPV/Hib.In addition,caregivers in urban areas showed more concern about the vaccine price(P=0.010)and immunization schedule(P=0.022)in regard to vaccinating children.Conclusions The DTaP-IPV/Hib vaccine coverage rate in Hainan Province remains low.Factors such as lower socioeconomi展开更多
This study evaluated the immunogenicity and protective immunity of a Hemophilus influenzae b （Hib） polysaccharide conjugate vaccine with the pneumococcal surface adhesin A （PsaA） protein carrier in young mice. The...This study evaluated the immunogenicity and protective immunity of a Hemophilus influenzae b （Hib） polysaccharide conjugate vaccine with the pneumococcal surface adhesin A （PsaA） protein carrier in young mice. The Hib polysaccharide was conjugated with the rPsaA protein carrier, which was produced using recombinant DNA technology. A total of 15 young mice aged 3 weeks to 5 weeks were immunized with the conjugate vaccine, and another 15 young mice of the same age were immunized with the licensed Hib-tetanus toxoid （TT） vaccine. Furthermore, the third group of 15 young mice was inoculated with phosphate buffer saline as control. The immunized mice were inoculated with pneumococcus in the middle ear. Results showed that IgG antibody responses against both the PsaA protein and Hib polysaccharide were observed in the Hib-PsaA group. However, no statistical difference was observed in the titer of ｜gG against the Hib polysaccharide between Hib-PsaA and Hib-TT groups. The elimination rate of pneumococcus and the inflammation of the middle ear showed the effectiveness of protective immunity against otitis media caused by pneumococcus. Our results suggest that the Hib polysaccharide can be successfully conjugated with rPsaA via amide condensation. This new Hib-PsaA conjugate vaccine can induce both anti-PsaA and anti-Hib immune responses in young mice and elicit effective protection against acute otitis media caused by pneumococcus.展开更多
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 species are Gram-negative coccobacilli that require factor X and factor V for growth. Beyond this, it is a finicky bacterium to culture, and any modification of culture procedures greatly reduces isolation...Haemophilus species are Gram-negative coccobacilli that require factor X and factor V for growth. Beyond this, it is a finicky bacterium to culture, and any modification of culture procedures greatly reduces isolation rates. Poor quality of laboratories in developing countries results in its poor isolation rates. This study was done with the objective of finding out the optimal cultural environment and media so that it could be maintained for a longer period in economical settings like ours which was done using H. influenzae ATCC 49,766. In this study, several culture media were tested as a means to preserve H. influenzae ATCC like TSB + glycerol + sheep blood, BHI broth, BHI broth + glycerol, BHI broth+ glycerol + sheep blood, Chocolate agar slant and satellitism plate. Three sets of respective media were inoculated with 18 - 24 hours growth of H. influenzae. They were incubated at 37?oC 48 hours in a candle extinction jar. The media were checked for growth by subculturing them on chocolate agar plates and identified by biochemical reactions. Each set was maintained at 2 oC - 8?oC, -20?oC and at room temperature and checked for the viability 24 hourly by subculturing them on chocolate agar. Results showed best growth of H. influenza on chocolate agar slants for 15 - 20 days, followed by BHI + glycerol + sheep blood broth and satellitism plate for 4 - 6 days followed by BHI broth for 2 - 4 days. There was no growth in TSB + glycerol + sheep blood broth and BHI + glycerol broth media. Present study showed similar results as done by NS Srikanth et al. 2003 with growth on chocolate agar & satellitism plate for 3 - 5 days but no growth in TSB + Glycerol + Sheep blood broth media. Chocolate agar slant is by far the most long term preserving media for H. influenzae. However, growth on BHI broth with various modifications is also showed a good preservation for 3 - 5 days, so with further experiments we can hope to maintain the organism in these media also.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
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
Antigenic determinants expressed on the bacterial cell surface are of importance in the serological characterization and microbiological diagnosis. The bacterial strains carrying these identical or similar antigenic e...Antigenic determinants expressed on the bacterial cell surface are of importance in the serological characterization and microbiological diagnosis. The bacterial strains carrying these identical or similar antigenic epitopes might react with antibodies produced against other strains. In this study, strong immunogenicity and antigenic cross reactivity were demonstrated among V. cholerae O1, S. flexnerii 2a and H. influenzae b surface components. The enzyme linked immunosorbent assay （ELISA） results were supported by Western blot analysis, where at least 20 antigenic bands, were obtained in each of the reactions, when the surface components were reacted with the homologous antisera. The indirect ELISA results also demonstrated high degree of antigenic relatedness between the surface components of these species, where each surface component was reacted with the heterologous antisera. Western blot analysis also revealed cross reactions between the surface components suggesting common distribution of antigens/epitopes in these bacterial species. This study, thus, gave a clear idea of the level of antigenic sharing and variations among the pathogenic V. cholerae O1, S. flexneri 2a and H. influenzae b strains, which in future, may help in selecting a proper candidate for vaccines and immunodiagnostics development.展开更多
The relationship between pharmacokinetics and pharmacodynamics is a key instrument to improve antimicrobial stewardship and should be aimed to identification of the drug exposure measure that is closely associated not...The relationship between pharmacokinetics and pharmacodynamics is a key instrument to improve antimicrobial stewardship and should be aimed to identification of the drug exposure measure that is closely associated not only with the ability to kill organisms but also to suppress the emergence of resistant subpopulations. This article reviews published studies for efficacy prediction with cefditoren and those aimed to explore its potential for countering resistance spread, focusing on the three most prevalent community-acquired isolates from respiratory infections: Streptococcus pneumoniae(S. pneumoniae), Haemophilus influenzae(H. influenzae) and Streptococcus pyogenes(S. pyogenes). Studies for efficacy prediction include in vitro pharmacodynamic simulations(using physiological concentrations of human albumin) and mice models(taking advantage of the same protein binding rate in mice and humans) to determine the value of the pharmacodynamic indices predicting efficacy, and Monte Carlo simulations to explore population pharmacodynamic coverage, as weapons for establishing breakpoints. Studies exploring the potential of cefditoren(free concentrations obtained with 400 mg cefditoren bid administration) for countering spread of resistance showed itscapability for countering(1) intra-strain spread of resistance linked to fts I gene mutations in H. influenzae;(2) the spread of H. influenzae resistant strains(with fts I gene mutations) in multi-strain H. influenzae niches or of S. pneumoniae strains with multiple resistance traits in multi-strain S. pneumoniae niches; and(3) for overcoming indirect pathogenicity linked to β-lactamase production by H. influenzae that protects S. pyogenes in multibacterial niches. This revision evidences the ecological potential for cefditoren(countering resistance spread among human-adapted commensals) and its adequate pharmacodynamic coverage of respiratory pathogens(including those resistant to previous oral compounds) producing community-acquired infections.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
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
Diseases caused by microbial bacteria such as Haemophilus influenzae type b(Hib),Streptococcus pneumoniae and Neisseria meningitidis are still very serious disease,which has brought a lot of burden to many countries.D...Diseases caused by microbial bacteria such as Haemophilus influenzae type b(Hib),Streptococcus pneumoniae and Neisseria meningitidis are still very serious disease,which has brought a lot of burden to many countries.Development of vaccine has brought hope for the prevention of such diseases.Polysaccharide conjugate vaccines have been shown to have very good effects in preventing such diseases.The polysaccharide co njugate vaccine adds the positive characteristics of protein antigens to the polysaccharide antigen,thereby improving the immunogenicity of the polysaccharide antigen,solving the problem that the polysaccharide vaccine cannot be effectively applicated in toddler or children,which greatly promoting the development of this vaccine.This review introduces the progress of polysaccharide conjugate vaccines.We introduce the typical polysaccharide conjugate vaccines currently on the market firstly,and then elucidate the protein carriers,the coupling chemistry methods and quality control that required in the preparation of polysaccharide conjugate vaccines.We can see that polysaccharide conjugate vaccine is a kind of vaccine with great development potential,which can be a sharp edge for us to prevent diseases.展开更多
文摘Pneumonia, the most typical and frequent lower respiratory tract infection （LRTI）, is a leading cause of health problems in the United States. Bacteria represent the most prevailing cause of pneumonia in both children and adults. Although pneumonia with a single bacterial infection is common, a significant portion of patients with pneumonia is polymicrobial. This infection is often complexed with other physiological factors such as cytokines and growth factors. Nontypeable Haemophilus influenzae （NTHi） is the most frequently recovered Gram-negative bacterial pathogen in the respiratory system and induces strong inflammatory responses. NTHi also synergizes with other respiratory pathogens, such as Streptococcus pneumoniae and respiratory viruses and pro-inflammatory cytokines, such as tumor necrosis factor-alpha （TNF-α）. It is noteworthy that NTHi not only synergizes with growth factors such as transforming growth factor-beta （TGF-β）, but also utilizes growth factor receptors such as TGF-β receptor and epidermal growth factor receptor （EGFR）, to enhance inflammatory responses. Although appropriate inflammation is a protective response against invading pathogens, an uncontrolled inflammatory response is often detrimental to the host. Thus, inflammation must be tightly regulated. The human immune system has evolved strategies for controlling overactive inflammatory response. One such important mechanism is via regulation of negative feedback regulators for inflammation. CYLD, a multifunctional deubiquitinase, was originally reported as a tumor suppressor, but was recently identified as a negative regulator for nuclear factor-kappa B （NF-κB） signaling. It is induced by NTHi and TNF-α via a NF-κB-dependent mechanism, thereby serving as an inducible negative feedback regulator for tightly controlling inflammation in NTHi infection.
文摘目的建立一种b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)结合疫苗中游离多糖含量新的检测方法。方法分别对标准蛋白溶液、多糖溶液和标加衍生多糖(AH-PRP)的结合物原液进行脱氧胆酸钠(NaDC)酸沉淀处理,观察该方法对蛋白和多糖的沉淀效果。分别采用NaDC酸沉淀法和乙醇分步沉淀法测定结合疫苗原液中的游离多糖含量。结果不同浓度的标准蛋白溶液经NaDC酸沉淀法处理后,沉淀中蛋白的回收率在96%～99%之间;不同浓度的多糖溶液经NaDC酸沉淀法处理后,上清中的多糖回收率在99%～106%之间;该方法对结合物中的游离多糖能起到很好的分离效果;两种方法测定结合疫苗原液中的游离多糖含量差异有统计学意义(P<0.01)。结论 NaDC酸沉淀法能专一性地沉淀蛋白物质,对游离多糖无沉淀作用,该方法具有良好的重复性和准确性,可用于测定Hib结合疫苗中的游离多糖含量。
文摘HACEK organisms represent a rare but important group of causative pathogens in endocarditis. These bacteria have historically been associated with culture-negative endocarditis;however, modern laboratory techniques have made this less common. In this case, we present a 74-year-old man who presented with acute onset altered mentation, fever, and sepsis. He was ultimately found to have Haemophilus influenzae meningitis, cerebral empyema, aortic valve endocarditis, psoas myositis, and L2 - L3 diskitis with osteomyelitis. Although HACEK organisms are commonly found in the oropharynx and upper respiratory tract in humans, our patient did not report recent preceding dental or ENT procedures. H. influenzae is responsible for approximately 0.16% of all cases of bacterial endocarditis, representing a very limited subset. Although generally considered low virulent pathogens, this case demonstrates the unusual extent of infection from a HACEK organism, H. influenzae, causing aortic valve endocarditis as well as atypical non-cardiac sequelae, including acute meningitis.
基金This research was supported by a grant from the Natural Science Foundation of China （No. 30670927）.
文摘Background It is recognized that Haemophilus influenzae isolated from patients with otitis media forms biofilms both in vitro and in vivo, suggesting that biofilm formation in vivo might play an important role in the pathogenesis and chronicity of otitis media, but the effect of antibiotics on biofilm has not been well studied. We investigated the impact of ciprofloxacin and azithromycin on bacterial biofilms formed by Haemophilus influenzae in vitro in this study. Methods Eleven strains of Haemophilus influenzae were isolated from sputum specimens collected from patients with acute exacerbation of chronic obstructive pulmonary diseases. Formation of bacterial biofUm was examined by crystal violet assay and a scanning electron microscope. Alterations of biofilms were measured under varying concentrations of azithromycin and ciprofloxacin. Results Striking differences were observed among strains with regard to the ability to form biofilm. Typical membrane-like structure formed by bacterial cells and extracellular matrix was detected. Initial biofilm synthesis was inhibited by azithromycin and ciprofloxacin at concentrations higher than two-fold minimal inhibitory concentration. Disruption of mature biofilms could be achieved at relatively higher concentration, and ciprofloxacin displayed more powerful activity. Conclusions Haemophilus influenzae is capable of forming biofilm in vitro. Sufficient dosage might control early formation of biofilms. Ciprofloxacin exerts better effects on breakdown of biofilm than azithromycin at conventional concentration in clinics.
基金This work was supported by the Bill&Melinda Gates Foundation(Grant No.INV-049539)the Key Research and Development Program of Hainan Province(Grant No.ZDYF2020210)+1 种基金the Project of the National Social Science Fund of China(Grant No.20BGL264)the Shanghai Public Health System Construction Three-Year Action Plan(Grant No.GWVI-11.1-48)。
文摘Background Immunization is one of the most far-reaching and cost-effective strategies for promoting good health and saving lives.A complex immunization schedule,however,may be burdensome to parents and lead to reduced vaccine compliance and completion.Thus,it is critical to develop combination vaccines to reduce the number of injections and simplify the immunization schedule.This study aimed to investigate the current status of the pentavalent diphtheria-tetanus-acellular pertussis inactivated poliomyelitis andHaemophilus influenzae type B conjugate(DTaP-IPV/Hib)vaccination in Southern China as well as explore the factors in the general population associated with uptake and the differences between urban and rural populations.Methods A cross-sectional study was conducted with recently enrolled kindergarten students in Hainan Province between December 2022 and January 2023.The study employed a stratified multistage cluster random sampling method.Information regarding the demographic characteristics and factors that influence decisions were collected from the caregivers of children via an online questionnaire.Multivariate logistic regression was used to determine the factors associated with the status of DTap-IPV/Hib vaccinations.Results Of the 4818 valid responses,95.3%of children were aged 3-4 years,and 2856(59.3%)held ruralhukou.Coverage rates of the DTaP-IPV/Hib vaccine,from 1 to 4 doses,were 24.4%,20.7%,18.5%,and 16.0%,respectively.Caregivers who are concerned about vaccine efficacy[adjusted odds ratio(aOR)=1.53,95%confidence interval(CI):1.30-1.79],the manufacturer(aOR=2.05,95%CI:1.69-2.49),and a simple immunization schedule(aOR=1.26,95%CI:1.04-1.54)are factors associated with a higher likelihood of vaccinating children against DTaP-IPV/Hib.In addition,caregivers in urban areas showed more concern about the vaccine price(P=0.010)and immunization schedule(P=0.022)in regard to vaccinating children.Conclusions The DTaP-IPV/Hib vaccine coverage rate in Hainan Province remains low.Factors such as lower socioeconomi
基金This research work was fimded by the Natural Science Foundation of Shanghai from the Science and Technology Commission of Shanghai Municipality （No. 14ZR1405700）.
文摘This study evaluated the immunogenicity and protective immunity of a Hemophilus influenzae b （Hib） polysaccharide conjugate vaccine with the pneumococcal surface adhesin A （PsaA） protein carrier in young mice. The Hib polysaccharide was conjugated with the rPsaA protein carrier, which was produced using recombinant DNA technology. A total of 15 young mice aged 3 weeks to 5 weeks were immunized with the conjugate vaccine, and another 15 young mice of the same age were immunized with the licensed Hib-tetanus toxoid （TT） vaccine. Furthermore, the third group of 15 young mice was inoculated with phosphate buffer saline as control. The immunized mice were inoculated with pneumococcus in the middle ear. Results showed that IgG antibody responses against both the PsaA protein and Hib polysaccharide were observed in the Hib-PsaA group. However, no statistical difference was observed in the titer of ｜gG against the Hib polysaccharide between Hib-PsaA and Hib-TT groups. The elimination rate of pneumococcus and the inflammation of the middle ear showed the effectiveness of protective immunity against otitis media caused by pneumococcus. Our results suggest that the Hib polysaccharide can be successfully conjugated with rPsaA via amide condensation. This new Hib-PsaA conjugate vaccine can induce both anti-PsaA and anti-Hib immune responses in young mice and elicit effective protection against acute otitis media caused by pneumococcus.
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 species are Gram-negative coccobacilli that require factor X and factor V for growth. Beyond this, it is a finicky bacterium to culture, and any modification of culture procedures greatly reduces isolation rates. Poor quality of laboratories in developing countries results in its poor isolation rates. This study was done with the objective of finding out the optimal cultural environment and media so that it could be maintained for a longer period in economical settings like ours which was done using H. influenzae ATCC 49,766. In this study, several culture media were tested as a means to preserve H. influenzae ATCC like TSB + glycerol + sheep blood, BHI broth, BHI broth + glycerol, BHI broth+ glycerol + sheep blood, Chocolate agar slant and satellitism plate. Three sets of respective media were inoculated with 18 - 24 hours growth of H. influenzae. They were incubated at 37?oC 48 hours in a candle extinction jar. The media were checked for growth by subculturing them on chocolate agar plates and identified by biochemical reactions. Each set was maintained at 2 oC - 8?oC, -20?oC and at room temperature and checked for the viability 24 hourly by subculturing them on chocolate agar. Results showed best growth of H. influenza on chocolate agar slants for 15 - 20 days, followed by BHI + glycerol + sheep blood broth and satellitism plate for 4 - 6 days followed by BHI broth for 2 - 4 days. There was no growth in TSB + glycerol + sheep blood broth and BHI + glycerol broth media. Present study showed similar results as done by NS Srikanth et al. 2003 with growth on chocolate agar & satellitism plate for 3 - 5 days but no growth in TSB + Glycerol + Sheep blood broth media. Chocolate agar slant is by far the most long term preserving media for H. influenzae. However, growth on BHI broth with various modifications is also showed a good preservation for 3 - 5 days, so with further experiments we can hope to maintain the organism in these media also.
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Antigenic determinants expressed on the bacterial cell surface are of importance in the serological characterization and microbiological diagnosis. The bacterial strains carrying these identical or similar antigenic epitopes might react with antibodies produced against other strains. In this study, strong immunogenicity and antigenic cross reactivity were demonstrated among V. cholerae O1, S. flexnerii 2a and H. influenzae b surface components. The enzyme linked immunosorbent assay （ELISA） results were supported by Western blot analysis, where at least 20 antigenic bands, were obtained in each of the reactions, when the surface components were reacted with the homologous antisera. The indirect ELISA results also demonstrated high degree of antigenic relatedness between the surface components of these species, where each surface component was reacted with the heterologous antisera. Western blot analysis also revealed cross reactions between the surface components suggesting common distribution of antigens/epitopes in these bacterial species. This study, thus, gave a clear idea of the level of antigenic sharing and variations among the pathogenic V. cholerae O1, S. flexneri 2a and H. influenzae b strains, which in future, may help in selecting a proper candidate for vaccines and immunodiagnostics development.
文摘The relationship between pharmacokinetics and pharmacodynamics is a key instrument to improve antimicrobial stewardship and should be aimed to identification of the drug exposure measure that is closely associated not only with the ability to kill organisms but also to suppress the emergence of resistant subpopulations. This article reviews published studies for efficacy prediction with cefditoren and those aimed to explore its potential for countering resistance spread, focusing on the three most prevalent community-acquired isolates from respiratory infections: Streptococcus pneumoniae(S. pneumoniae), Haemophilus influenzae(H. influenzae) and Streptococcus pyogenes(S. pyogenes). Studies for efficacy prediction include in vitro pharmacodynamic simulations(using physiological concentrations of human albumin) and mice models(taking advantage of the same protein binding rate in mice and humans) to determine the value of the pharmacodynamic indices predicting efficacy, and Monte Carlo simulations to explore population pharmacodynamic coverage, as weapons for establishing breakpoints. Studies exploring the potential of cefditoren(free concentrations obtained with 400 mg cefditoren bid administration) for countering spread of resistance showed itscapability for countering(1) intra-strain spread of resistance linked to fts I gene mutations in H. influenzae;(2) the spread of H. influenzae resistant strains(with fts I gene mutations) in multi-strain H. influenzae niches or of S. pneumoniae strains with multiple resistance traits in multi-strain S. pneumoniae niches; and(3) for overcoming indirect pathogenicity linked to β-lactamase production by H. influenzae that protects S. pyogenes in multibacterial niches. This revision evidences the ecological potential for cefditoren(countering resistance spread among human-adapted commensals) and its adequate pharmacodynamic coverage of respiratory pathogens(including those resistant to previous oral compounds) producing community-acquired infections.
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.
基金funded by National Natural Science Foundation of China(No.82073311)Key Research Development Program of Science and Technology Department of Sichuan Provincial(No.2019YFS0514)+4 种基金National Natural Science Foundation of China(No.81741100)the Natural Science Foundation of Beijing,China(No.6181001)National Key Research and Development Program of China(No.2020YFC2005500)Key Research and Development Program of Science and Technology Department of Sichuan Province(No.2019YFS0514)The Major Science and Technology R&G Program of Jiangxi Province(No.20194ABC28007)。
文摘Diseases caused by microbial bacteria such as Haemophilus influenzae type b(Hib),Streptococcus pneumoniae and Neisseria meningitidis are still very serious disease,which has brought a lot of burden to many countries.Development of vaccine has brought hope for the prevention of such diseases.Polysaccharide conjugate vaccines have been shown to have very good effects in preventing such diseases.The polysaccharide co njugate vaccine adds the positive characteristics of protein antigens to the polysaccharide antigen,thereby improving the immunogenicity of the polysaccharide antigen,solving the problem that the polysaccharide vaccine cannot be effectively applicated in toddler or children,which greatly promoting the development of this vaccine.This review introduces the progress of polysaccharide conjugate vaccines.We introduce the typical polysaccharide conjugate vaccines currently on the market firstly,and then elucidate the protein carriers,the coupling chemistry methods and quality control that required in the preparation of polysaccharide conjugate vaccines.We can see that polysaccharide conjugate vaccine is a kind of vaccine with great development potential,which can be a sharp edge for us to prevent diseases.
