Sample records for haemophilus somnus exposure

  1. Haemophilus somnus (Histophilus somni) in bighorn sheep.

    PubMed

    Ward, Alton C S; Weiser, Glen C; Anderson, Bruce C; Cummings, Patrick J; Arnold, Karen F; Corbeil, Lynette B

    2006-01-01

    Respiratory disease and poor lamb recruitment have been identified as limiting factors for bighorn-sheep populations. Haemophilus somnus (recently reclassified as Histophilus somni) is associated with respiratory disease in American bison, domestic sheep, and cattle. It is also harbored in their reproductive tracts and has been associated with reproductive failure in domestic sheep and cattle. Therefore, reproductive tract and lung samples from bighorn sheep were evaluated for the presence of this organism. Organisms identified as H. somnus were isolated from 6 of 62 vaginal but none of 12 preputial swab samples. Antigen specific to H. somnus was detected by immunohistochemical study in 4 of 12 formalin-fixed lung tissue samples of bighorn sheep that died with evidence of pneumonia. Notably, H. somnus was found in alveolar debris in areas of inflammation. The 6 vaginal isolates and 2 H. somnus isolates previously cultured from pneumonic lungs of bighorn sheep were compared with 3 representative isolates from domestic sheep and 2 from cattle. The profiles of major outer membrane proteins and antigens for all of the isolates were predominantly similar, although differences that may be associated with the host-parasite relationship and virulence were detected. The DNA restriction fragment length profiles of the bighorn-sheep isolates had similarities not shared with the other isolates, suggesting distinct phylogenetic lines. All of the isolates had similar antimicrobial profiles, but the isolates from the bighorn sheep produced less pigment than those from the domestic livestock, and growth of the former was not enhanced by CO2. Wildlife biologists and diagnosticians should be aware of the potential of these organisms to cause disease in bighorn sheep and of growth characteristics that may hinder laboratory detection.

  2. Haemophilus somnus (Histophilus somni) in bighorn sheep

    PubMed Central

    2006-01-01

    Abstract Respiratory disease and poor lamb recruitment have been identified as limiting factors for bighorn-sheep populations. Haemophilus somnus (recently reclassified as Histophilus somni) is associated with respiratory disease in American bison, domestic sheep, and cattle. It is also harbored in their reproductive tracts and has been associated with reproductive failure in domestic sheep and cattle. Therefore, reproductive tract and lung samples from bighorn sheep were evaluated for the presence of this organism. Organisms identified as H. somnus were isolated from 6 of 62 vaginal but none of 12 preputial swab samples. Antigen specific to H. somnus was detected by immunohistochemical study in 4 of 12 formalin-fixed lung tissue samples of bighorn sheep that died with evidence of pneumonia. Notably, H. somnus was found in alveolar debris in areas of inflammation. The 6 vaginal isolates and 2 H. somnus isolates previously cultured from pneumonic lungs of bighorn sheep were compared with 3 representative isolates from domestic sheep and 2 from cattle. The profiles of major outer membrane proteins and antigens for all of the isolates were predominantly similar, although differences that may be associated with the host–parasite relationship and virulence were detected. The DNA restriction fragment length profiles of the bighorn-sheep isolates had similarities not shared with the other isolates, suggesting distinct phylogenetic lines. All of the isolates had similar antimicrobial profiles, but the isolates from the bighorn sheep produced less pigment than those from the domestic livestock, and growth of the former was not enhanced by CO2. Wildlife biologists and diagnosticians should be aware of the potential of these organisms to cause disease in bighorn sheep and of growth characteristics that may hinder laboratory detection. PMID:16548330

  3. Preimplantation bovine embryos: Pathobiology of Haemophilus somnus exposure and resistance mechanisms to vesicular stomatitis virus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thomson, M.S.

    1988-01-01

    Preimplantation bovine embryos were exposed in vitro to H. somnus to determine if the bacteria would adhere to zona pellucida-intact (ZP-I) embryos or adhere to or infect ZP-free embryos. The effect of H. somnus on embryonic development in vitro was also investigated. Electrophoretic comparisons of outer membrane proteins of H. somnus revealed 2 major protein bands common to 10 H. somnus isolates. A monoclonal antibody produced against the outer membrane proteins reacted to one of the major protein bands. The sensitivity of a nucleic acid probe for detection of vesicular stomatitis virus (VSV) was validated in cells in culture andmore » used to determine if the synthetic double-stranded complex of polyriboinosinic and polyribocytidylic acids (poly I:C) would induce viral resistance in cultured bovine embryos. Two {sup 32}P-nick translated probes of high specific activity prepared from plasmids containing nucleic acid sequences of VSV virus were employed for viral mRNA detection in the tissue culture cells using a DNA-hybridization dot-blot technique. Using one of the probes, the technique was applied to detect differences in viral replication between four groups of bovine embryos (nonexposed, exposed to VSV virus, poly I:C-treated, and poly I:C-treated and exposed to VSV). The nucleic acid probe was sufficiently sensitive to detect differences in quantities of VSV mRNA among embryo treatment groups, resulting in the demonstration that resistance to viral infection was induced in day 9 bovine embryos.« less

  4. Detection of the Haemophilus somnus antibodies in the bulls' reproductive tract fluids using the ELISA. I. Elaboration of the ELISA for the detection of the specific antibodies in the IgG, IgM and IgA classes.

    PubMed

    Stefaniak, T

    1993-01-01

    The conditions of the ELISA for detecting the Haemophilus somnus antibodies in IgG, IgM and IgA classes were elaborated. The test was adapted for examining the seminal plasma, preputial washings and blood serum samples of bulls. In order to obtain the more precise evaluation of results, the tests were made for two different dilutions of the examined material. The arising out of this method difficulty in the evaluation of the intensity of reaction was solved by introducing the specific, semi-quantitative method of classification, using the eleven-degree scale. The mean arithmetic classificational values calculated from absorbance readings were called "absorbance index". The introduced parameter proved to be especially useful while comparing the reaction of antibodies in reproductive tract fluids samples.

  5. Cloning and Characterization of the Lipooligosaccharide Galactosyltransferase II Gene of Haemophilus ducreyi

    PubMed Central

    Sun, Shuhua; Schilling, Birgit; Tarantino, Laurie; Tullius, Michael V.; Gibson, Bradford W.; Munson, Robert S.

    2000-01-01

    Haemophilus ducreyi is the etiologic agent of chancroid, a genital ulcer disease. The lipooligosaccharide (LOS) is considered to be a major virulence determinant and has been implicated in the adherence of H. ducreyi to keratinocytes. Strain A77, an isolate from the Paris collection, is serum sensitive, poorly adherent to fibroblasts, and deficient in microcolony formation. Structural analysis indicates that the LOS of strain A77 lacks the galactose residue found in the N-acetyllactosamine portion of the strain 35000HP LOS as well as the sialic acid substitution. From an H. ducreyi 35000HP genomic DNA library, a clone complementing the defect in A77 was identified by immunologic screening with monoclonal antibody (MAb) 3F11, a MAb which recognizes the N-acetyllactosamine portion of strain 35000HP LOS. The clone contained a 4-kb insert that was sequenced. One open reading frame which encodes a protein with a molecular weight of 33,400 was identified. This protein has homology to glycosyltransferases of Haemophilus influenzae, Haemophilus somnus, Neisseria species, and Pasteurella haemolytica. The putative H. ducreyi glycosyltransferase gene was insertionally inactivated, and an isogenic mutant of strain 35000HP was constructed. The most complex LOS glycoform produced by the mutant has a mobility on sodium dodecyl sulfate-polyacrylamide gel identical to that of the LOS of strain A77 and lacks the 3F11-binding epitope. Structural studies confirm that the most complex glycoform of the LOS isolated from the mutant lacks the galactose residue found in the N-acetyllactosamine portion of the strain 35000HP LOS. Although previously published data suggested that the serum-sensitive phenotype of A77 was due to the LOS mutation, we observed that the complemented A77 strain retained its serum-sensitive phenotype and that the galactosyltransferase mutant retained its serum-resistant phenotype. Thus, the serum sensitivity of strain A77 cannot be attributed to the

  6. The SomnuSeal Oral Mask Is Reasonably Tolerated by Otherwise CPAP Noncompliant Patients with OSA

    PubMed Central

    Katz, N.; Adir, Y.; Etzioni, T.; Kurtz, E.; Pillar, G.

    2013-01-01

    Compliance with CPAP is the major limiting factor in treating patients with OSA. The novel SomnuSeal mask is an oral self-adaptable mask located between the teeth and the lips ensuring that there are no air leaks or skin abrasions. Fifty patients with AHI > 20, who failed previous CPAP trials, were asked to sleep with the mask for one month. In all patients, the mask was connected to an AutoPAP machine with a heated humidifier. Efficacy, convenience, and compliance (average usage for 4 or more hours per night) were monitored. Fifty patients (41 m and 9 f, mean age 57 ± 12 years, BMI 33.6 ± 4.9 kg/m2, and AHI 47 ± 23/h) participated. Eleven were classified as compliant (average mask usage of 26 nights, 4.7 hours per night), five were only partially compliant (average usage of 13 nights, 2.9 hours per night), and 34 could not comply with it. In all patients who slept with it, the efficacy (assessed by residual AHI derived from the CPAP device) was good with an AHI of less than 8/hour. Interestingly, the required optimal pressure decreased from an average of 9.3 cmH2O to 4.6 cmH2O. The SomnuSeal oral interface is effective and may result in converting noncompliant untreated patients with OSA into well-treated ones. PMID:24228181

  7. Haemophilus influenzae and the lung (Haemophilus and the lung)

    PubMed Central

    2012-01-01

    Haemophilus influenzae is present as a commensal organism in the nasopharynx of most healthy adults from where it can spread to cause both systemic and respiratory tract infection. This bacterium is divided into typeable forms (such as type b) or nontypeable forms based on the presence or absence of a tough polysaccharide capsule. Respiratory disease is predominantly caused by the nontypeable forms (NTHi). Haemophilus influenzae has evolved a number of strategies to evade the host defense including the ability to invade into local tissue. Pathogenic properties of this bacterium as well as defects in host defense may result in the spread of this bacterium from the upper airway to the bronchi of the lung. This can result in airway inflammation and colonization particularly in chronic obstructive pulmonary disease. Treatment of respiratory tract infection with Haemophilus influenzae is often only partially successful with ongoing infection and inflammation. Improvement in patient outcome will be dependent on a better understanding of the pathogenesis and host immune response to this bacterium. PMID:23369277

  8. Haemophilus influenzae serotype a meningitis.

    PubMed

    de Pádua, Rubia Andreia Falleiros; de Lima Scodro, Regiane Bertin; Ghiraldi, Luciana Dias; Siqueira, Vera Lúcia Dias; Yamashita, Yandara Keiko; Helbel, César; Cardoso, Rosilene Fressatti

    2009-01-01

    This work describes a case of Haemophilus influenzae serotype a meningitis in Brazil, after almost a decade since the introduction of Haemophilus influenzae serotype b conjugate vaccine. Uncertainty about the replacement of H. influenzae serotypes as a cause of invasive diseases justifies continuous surveillance, coupled with investigations of carriage rates and requirements of chemoprophylaxis in contact persons.

  9. Haemophilus haemolyticus isolates causing clinical disease.

    PubMed

    Anderson, Raydel; Wang, Xin; Briere, Elizabeth C; Katz, Lee S; Cohn, Amanda C; Clark, Thomas A; Messonnier, Nancy E; Mayer, Leonard W

    2012-07-01

    We report seven cases of Haemophilus haemolyticus invasive disease detected in the United States, which were previously misidentified as nontypeable Haemophilus influenzae. All cases had different symptoms and presentations. Our study suggests that a testing scheme that includes reliable PCR assays and standard microbiological methods should be used in order to improve H. haemolyticus identification.

  10. Chancroid and Haemophilus ducreyi.

    PubMed Central

    Morse, S A

    1989-01-01

    Haemophilus ducreyi is the causative agent of chancroid, one of the genital ulcerative diseases. H. ducreyi is the major cause of genital ulcer disease in Africa and Southeast Asia and is of increasing concern in the United States. Definitive diagnosis of chancroid requires the isolation and identification of H. ducreyi, but isolation of this organism is difficult and the available medium is not optimal for all strains. Fluorescent antibody and serologic tests are of limited value. In general, our knowledge of this organism is rather limited, and indeed, recent studies have questioned the placement of H. ducreyi in the genus Haemophilus. H. ducreyi has relatively few biochemical activities, and epidemiologic studies are limited because there are limited phenotypic markers available for strain typing. Specific virulence factors of H. ducreyi have yet to be identified. Antimicrobial resistance in H. ducreyi is of special concern, as this organism has acquired both gram-negative and gram-positive resistance determinants. In addition, some of these determinants can be mobilized and transferred to other Haemophilus species or to Neisseria gonorrhoeae. Images PMID:2650859

  11. Haemophilus haemolyticus Isolates Causing Clinical Disease

    PubMed Central

    Wang, Xin; Briere, Elizabeth C.; Katz, Lee S.; Cohn, Amanda C.; Clark, Thomas A.; Messonnier, Nancy E.; Mayer, Leonard W.

    2012-01-01

    We report seven cases of Haemophilus haemolyticus invasive disease detected in the United States, which were previously misidentified as nontypeable Haemophilus influenzae. All cases had different symptoms and presentations. Our study suggests that a testing scheme that includes reliable PCR assays and standard microbiological methods should be used in order to improve H. haemolyticus identification. PMID:22573587

  12. Molecular tools for differentiation of non-typeable Haemophilus influenzae from Haemophilus haemolyticus

    PubMed Central

    Pickering, Janessa; Richmond, Peter C.; Kirkham, Lea-Ann S.

    2014-01-01

    Non-typeable Haemophilus influenzae (NTHi) and Haemophilus haemolyticus are closely related bacteria that reside in the upper respiratory tract. NTHi is associated with respiratory tract infections that frequently result in antibiotic prescription whilst H. haemolyticus is rarely associated with disease. NTHi and H. haemolyticus can be indistinguishable by traditional culture methods and molecular differentiation has proven difficult. This current review chronologically summarizes the molecular approaches that have been developed for differentiation of NTHi from H. haemolyticus, highlighting the advantages and disadvantages of each target and/or technique. We also provide suggestions for the development of new tools that would be suitable for clinical and research laboratories. PMID:25520712

  13. Meningitis due to Haemophilus influenzae type f.

    PubMed

    Cardoso, Marta Pessoa; Pasternak, Jacyr; Giglio, Alfredo Elias; Casagrande, Rejane Rimazza Dalberto; Troster, Eduardo Juan

    2013-12-01

    With the decline in the rate of infections caused by Haemophilus influenzae serotype b since the widespread vaccination, non-b serotypes should be considered as potential pathogenic agents in children with invasive disease younger than 5 years old. We report the case of an immunocompetent 1-year-old boy with Haemophilus influenzae type f meningitis. The agent was identified in cerebrospinal fluid and blood cultures. Serotyping was performed by tests using polyclonal sera and confirmed by polymerase chain reaction. All Haemophilus influenzae isolates associated with invasive disease should be serotyped and notified as a way to evaluate the changes and trends in serotype distribution of this disease.

  14. Molecular basis of antimicrobial resistance in non-typable Haemophilus influenzae.

    PubMed

    Sánchez, L; Leranoz, S; Puig, M; Lorén, J G; Nikaido, H; Viñas, M

    1997-09-01

    Strains of the facultative anaerobe Haemophilus influenzae, both type b and non typable strains, are frequently multiresistant. The measurement of the antibiotic permeability of Haemophilus influenzae outer membrane (OM) shows that antibiotics can cross through the OM easily. Thus, enzymatic activity or efflux pumps could be responsible for multiresistance. An efflux system closely related to AcrAB of Escherichia coli is present in Haemophilus influenzae. However, their role in multiresistance seems irrelevant. Classical mechanisms such as plasmid exchange seems to be playing a major role in the multidrug resistance in Haemophilus influenzae.

  15. Culture and PCR Detection of Haemophilus influenzae and Haemophilus haemolyticus in Australian Indigenous Children with Bronchiectasis

    PubMed Central

    Binks, M. J.; Grimwood, K.; Chang, A. B.; Leach, A. J.; Smith-Vaughan, H.

    2012-01-01

    A PCR for protein D (hpd#3) was used to differentiate nontypeable Haemophilus influenzae (NTHI) from Haemophilus haemolyticus. While 90% of nasopharyngeal specimens and 100% of lower-airway specimens from 84 Indigenous Australian children with bronchiectasis had phenotypic NTHI isolates confirmed as H. influenzae, only 39% of oropharyngeal specimens with phenotypic NTHI had H. influenzae. The nasopharynx is therefore the preferred site for NTHI colonization studies, and NTHI is confirmed as an important lower-airway pathogen. PMID:22553240

  16. 21 CFR 866.3300 - Haemophilus spp. serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Haemophilus spp. serological reagents. 866.3300 Section 866.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3300 Haemophilus...

  17. 21 CFR 866.3300 - Haemophilus spp. serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Haemophilus spp. serological reagents. 866.3300 Section 866.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3300 Haemophilus...

  18. 21 CFR 866.3300 - Haemophilus spp. serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Haemophilus spp. serological reagents. 866.3300 Section 866.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3300 Haemophilus...

  19. 21 CFR 866.3300 - Haemophilus spp. serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Haemophilus spp. serological reagents. 866.3300 Section 866.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3300 Haemophilus...

  20. 21 CFR 866.3300 - Haemophilus spp. serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Haemophilus spp. serological reagents. 866.3300 Section 866.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3300 Haemophilus...

  1. About Haemophilus influenzae Disease

    MedlinePlus

    ... Links Global Hib Vaccination Hib Vaccination Meningitis Pneumonia Sepsis About Haemophilus influenzae Disease Recommend on Facebook Tweet ... Links Global Hib Vaccination Hib Vaccination Meningitis Pneumonia Sepsis File Formats Help: How do I view different ...

  2. Evaluation of new biomarker genes for differentiating Haemophilus influenzae from Haemophilus haemolyticus.

    PubMed

    Theodore, M Jordan; Anderson, Raydel D; Wang, Xin; Katz, Lee S; Vuong, Jeni T; Bell, Melissa E; Juni, Billie A; Lowther, Sara A; Lynfield, Ruth; MacNeil, Jessica R; Mayer, Leonard W

    2012-04-01

    PCR detecting the protein D (hpd) and fuculose kinase (fucK) genes showed high sensitivity and specificity for identifying Haemophilus influenzae and differentiating it from H. haemolyticus. Phylogenetic analysis using the 16S rRNA gene demonstrated two distinct groups for H. influenzae and H. haemolyticus.

  3. Evaluation of New Biomarker Genes for Differentiating Haemophilus influenzae from Haemophilus haemolyticus

    PubMed Central

    Anderson, Raydel D.; Wang, Xin; Katz, Lee S.; Vuong, Jeni T.; Bell, Melissa E.; Juni, Billie A.; Lowther, Sara A.; Lynfield, Ruth; MacNeil, Jessica R.; Mayer, Leonard W.

    2012-01-01

    PCR detecting the protein D (hpd) and fuculose kinase (fucK) genes showed high sensitivity and specificity for identifying Haemophilus influenzae and differentiating it from H. haemolyticus. Phylogenetic analysis using the 16S rRNA gene demonstrated two distinct groups for H. influenzae and H. haemolyticus. PMID:22301020

  4. Haemophilus Infections - Multiple Languages

    MedlinePlus

    ... gaw Karen) Khmer (ភាសាខ្មែរ) Kinyarwanda (Rwanda) Korean (한국어) Nepali (नेपाली) Oromo (Afan Oromoo) ... PDF Centers for Disease Control and Prevention Kinyarwanda (Rwanda) Expand Section Vaccine Information Statement (VIS) -- Haemophilus Influenzae ...

  5. Types of Haemophilus influenzae Infections

    MedlinePlus

    ... Links Global Hib Vaccination Hib Vaccination Meningitis Pneumonia Sepsis Types of Haemophilus influenzae Infections Recommend on Facebook ... Links Global Hib Vaccination Hib Vaccination Meningitis Pneumonia Sepsis File Formats Help: How do I view different ...

  6. Haemophilus influenzae Type b (Hib) vaccine - what you need to know

    MedlinePlus

    ... taken in its entirety from the CDC Hib (Haemophilus Influenzae Type b) Vaccine Information Statement (VIS): www. ... statements/hib.pdf . CDC review information for Hib (Haemophilus Influenzae Type b) VIS: Page last reviewed: April ...

  7. Classification, Identification, and Clinical Significance of Haemophilus and Aggregatibacter Species with Host Specificity for Humans

    PubMed Central

    2014-01-01

    SUMMARY The aim of this review is to provide a comprehensive update on the current classification and identification of Haemophilus and Aggregatibacter species with exclusive or predominant host specificity for humans. Haemophilus influenzae and some of the other Haemophilus species are commonly encountered in the clinical microbiology laboratory and demonstrate a wide range of pathogenicity, from life-threatening invasive disease to respiratory infections to a nonpathogenic, commensal lifestyle. New species of Haemophilus have been described (Haemophilus pittmaniae and Haemophilus sputorum), and the new genus Aggregatibacter was created to accommodate some former Haemophilus and Actinobacillus species (Aggregatibacter aphrophilus, Aggregatibacter segnis, and Aggregatibacter actinomycetemcomitans). Aggregatibacter species are now a dominant etiology of infective endocarditis caused by fastidious organisms (HACEK endocarditis), and A. aphrophilus has emerged as an important cause of brain abscesses. Correct identification of Haemophilus and Aggregatibacter species based on phenotypic characterization can be challenging. It has become clear that 15 to 20% of presumptive H. influenzae isolates from the respiratory tracts of healthy individuals do not belong to this species but represent nonhemolytic variants of Haemophilus haemolyticus. Due to the limited pathogenicity of H. haemolyticus, the proportion of misidentified strains may be lower in clinical samples, but even among invasive strains, a misidentification rate of 0.5 to 2% can be found. Several methods have been investigated for differentiation of H. influenzae from its less pathogenic relatives, but a simple method for reliable discrimination is not available. With the implementation of identification by matrix-assisted laser desorption ionization–time of flight mass spectrometry, the more rarely encountered species of Haemophilus and Aggregatibacter will increasingly be identified in clinical microbiology

  8. Identifying Haemophilus haemolyticus and Haemophilus influenzae by SYBR Green real-time PCR.

    PubMed

    Latham, Roger; Zhang, Bowen; Tristram, Stephen

    2015-05-01

    SYBR Green real time PCR assays for protein D (hpd), fuculose kinase (fucK) and [Cu, Zn]-superoxide dismutase (sodC) were designed for use in an algorithm for the identification of Haemophilus influenzae and H. haemolyticus. When tested on 127 H. influenzae and 60 H. haemolyticus all isolates were identified correctly. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  9. Genome Sequences for Five Strains of the Emerging Pathogen Haemophilus haemolyticus

    PubMed Central

    Jordan, I. King; Conley, Andrew B.; Antonov, Ivan V.; Arthur, Robert A.; Cook, Erin D.; Cooper, Guy P.; Jones, Bernard L.; Knipe, Kristen M.; Lee, Kevin J.; Liu, Xing; Mitchell, Gabriel J.; Pande, Pushkar R.; Petit, Robert A.; Qin, Shaopu; Rajan, Vani N.; Sarda, Shruti; Sebastian, Aswathy; Tang, Shiyuyun; Thapliyal, Racchit; Varghese, Neha J.; Ye, Tianjun; Katz, Lee S.; Wang, Xin; Rowe, Lori; Frace, Michael; Mayer, Leonard W.

    2011-01-01

    We report the first whole-genome sequences for five strains, two carried and three pathogenic, of the emerging pathogen Haemophilus haemolyticus. Preliminary analyses indicate that these genome sequences encode markers that distinguish H. haemolyticus from its closest Haemophilus relatives and provide clues to the identity of its virulence factors. PMID:21952546

  10. An isolate of Haemophilus haemolyticus produces a bacteriocin-like substance that inhibits the growth of nontypeable Haemophilus influenzae.

    PubMed

    Latham, Roger D; Gell, David A; Fairbairn, Rory L; Lyons, A Bruce; Shukla, Shakti D; Cho, Kum Yin; Jones, David A; Harkness, Nick M; Tristram, Stephen G

    2017-04-01

    Nontypeable Haemophilus influenzae (NTHi) frequently colonises the upper respiratory tract and is an important cause of respiratory infections. Resistance to antibiotics is an emerging trend in NTHi and alternative prevention or treatment strategies are required. Haemophilus haemolyticus is a common commensal occupying the same niche as NTHi and, if able to produce substances that inhibit NTHi growth, may have a role as a probiotic. In this study, ammonium sulphate extracts from broth culture of 100 H. haemolyticus isolates were tested for the presence of substances inhibitory to NTHi using a well diffusion assay. One isolate produced a substance that consistently inhibited the growth of NTHi. The substance was inactivated by protease enzymes and had a molecular size of ca. 30 kDa as determined by size exclusion chromatography. When the substance was tested against bacteria from eight Gram-negative and three Gram-positive genera, only Haemophilus spp. were inhibited. Quantitative PCR testing showed the substance to be different to 'haemocin', the previously described bacteriocin of H. influenzae type b. These molecular characteristics, together with narrow-spectrum activity, suggest the substance may be a novel bacteriocin, and there is potential for this H. haemolyticus isolate to function as a probiotic for reduction of colonisation and subsequent infection with NTHi. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  11. MALDI-TOF MS Distinctly Differentiates Nontypable Haemophilus influenzae from Haemophilus haemolyticus

    PubMed Central

    Zhang, Huifang; Zhang, Yongchan; Gao, Yuan; Xu, Li; Lv, Jing; Wang, Yingtong; Zhang, Jianzhong; Shao, Zhujun

    2013-01-01

    Nontypable Haemophilus influenzae (NTHi) and Haemophilus haemolyticus exhibit different pathogenicities, but to date, there remains no definitive and reliable strategy for differentiating these strains. In this study, we evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a potential method for differentiating NTHi and H. haemolyticus. The phylogenetic analysis of concatenated 16S rRNA and recombinase A (recA) gene sequences, outer membrane protein P6 gene sequencing and single-gene PCR were used as reference methods. The original reference database (ORD, provided with the Biotyper software) and new reference database (NRD, extended with Chinese strains) were compared for the evaluation of MALDI-TOF MS. Through a search of the ORD, 76.9% of the NTHi (40/52) and none of the H. haemolyticus (0/20) strains were identified at the species level. However, all NTHi and H. haemolyticus strains used for identification were accurately recognized at the species level when searching the NRD. From the dendrogram clustering of the main spectra projections, the Chinese and foreign H. influenzae reference strains were categorized into two distinct groups, and H. influenzae and H. haemolyticus were also separated into two categories. Compared to the existing methods, MALDI-TOF MS has the advantage of integrating high throughput, accuracy and speed. In conclusion, MALDI-TOF MS is an excellent method for differentiating NTHi and H. haemolyticus. This method can be recommended for use in appropriately equipped laboratories. PMID:23457514

  12. Haemophilus influenzae Genome Database (HIGDB): a single point web resource for Haemophilus influenzae.

    PubMed

    Swetha, Rayapadi G; Kala Sekar, Dinesh Kumar; Ramaiah, Sudha; Anbarasu, Anand; Sekar, Kanagaraj

    2014-12-01

    Haemophilus influenzae (H. Influenzae) is the causative agent of pneumonia, bacteraemia and meningitis. The organism is responsible for large number of deaths in both developed and developing countries. Even-though the first bacterial genome to be sequenced was that of H. Influenzae, there is no exclusive database dedicated for H. Influenzae. This prompted us to develop the Haemophilus influenzae Genome Database (HIGDB). All data of HIGDB are stored and managed in MySQL database. The HIGDB is hosted on Solaris server and developed using PERL modules. Ajax and JavaScript are used for the interface development. The HIGDB contains detailed information on 42,741 proteins, 18,077 genes including 10 whole genome sequences and also 284 three dimensional structures of proteins of H. influenzae. In addition, the database provides "Motif search" and "GBrowse". The HIGDB is freely accessible through the URL: http://bioserver1.physics.iisc.ernet.in/HIGDB/. The HIGDB will be a single point access for bacteriological, clinical, genomic and proteomic information of H. influenzae. The database can also be used to identify DNA motifs within H. influenzae genomes and to compare gene or protein sequences of a particular strain with other strains of H. influenzae. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Development of Competence of Haemophilus influenzae

    PubMed Central

    Spencer, Hugh T.; Herriott, Roger M.

    1965-01-01

    Spencer, Hugh T. (The Johns Hopkins University School of Hygiene and Public Health, Baltimore, Md.), and Roger M. Herriott. Development of competence of Haemophilus influenzae. J. Bacteriol. 90:911–920. 1965.—A chemically defined nongrowth medium was developed for the induction of competence of Haemophilus influenzae by a stepdown procedure. Cells grown logarithmically in Heart Infusion Broth became competent after being transferred to a medium which consisted of amino acids, sodium fumarate, and inorganic salts. Chloramphenicol (2 μg/ml) or l-valine (1 μg/ml) in the nongrowth medium inhibited development of competence. The inhibitory action of l-valine was reversed by comparable concentrations of l-isoleucine. Kinetic studies of the development of competence showed a variable capacity of competent cells to take up deoxyribonucleic acid and reaffirmed earlier findings that competence was not transmissible in H. influenzae. Addition of nicotinamide adenine dinucleotide, thiamine, calcium pantothenate, uracil, and hypoxanthine to the medium for competence resulted in a minimal growth medium in which reduced levels of competence were developed. PMID:5294817

  14. Low occurrence of 'non-haemolytic Haemophilus haemolyticus' misidentified as Haemophilus influenzae in cystic fibrosis respiratory specimens, and frequent recurrence of persistent H. influenzae clones despite antimicrobial treatment.

    PubMed

    Fenger, Mette G; Ridderberg, Winnie; Olesen, Hanne V; Nørskov-Lauritsen, Niels

    2012-12-01

    Non-influenzae commensal Haemophilus species of low pathogenicity may be difficult to discriminate from Haemophilus influenzae. We investigated the level of misidentifications in respiratory specimens from cystic fibrosis patients and evaluated the colonisation dynamics of genuine H. influenzae isolates. One hundred and ninety-two presumptive H. influenzae isolates were re-examined by assessment of marker genes sodC and fucK, and isolates with aberrant genotypes were subjected to multilocus sequence typing. Misidentifications (3%) were mainly caused by failure to identify porphyrin-synthesising strains, and only a single strain (0.5%) could be classified as 'non-haemolytic Haemophilus haemolyticus'. Sequential isolates of confirmed H. influenzae isolates from individual patients were typed by pulsed-field gel electrophoresis. Despite the routine prescription of antimicrobial therapy, the majority of H. influenzae isolates were identical with at least one of the strains cultured from the two preceding positive samples from the same patient. Copyright © 2012 Elsevier GmbH. All rights reserved.

  15. Minimum inhibitory concentrations of tulathromycin against respiratory bacterial pathogens isolated from clinical cases in European cattle and swine and variability arising from changes in in vitro methodology.

    PubMed

    Godinho, Kevin S; Keane, Sue G; Nanjiani, Ian A; Benchaoui, Hafid A; Sunderland, Simon J; Jones, M Anne; Weatherley, Andrew J; Gootz, Thomas D; Rowan, Tim G

    2005-01-01

    The in vitro activity of tulathromycin was evaluated against common bovine and porcine respiratory pathogens collected from outbreaks of clinical disease across eight European countries from 1998 to 2001. Minimum inhibitory concentrations (MICs) for one isolate of each bacterial species from each outbreak were determined using a broth microdilution technique. The lowest concentrations inhibiting the growth of 90% of isolates (MIC90) for tulathromycin were 2 microg/ml for Mannheimia (Pasteurella) haemolytica, 1 microg/ml for Pasteurella multocida (bovine), and 2 microg/ml for Pasteurella multocida (porcine) and ranged from 0.5 to 4 microg/ml for Histophilus somni (Haemophilus somnus) and from 4 to 16 microg/ml for Actinobacillus pleuropneumoniae. Isolates were retested in the presence of serum. The activity of tulathromycin against fastidious organisms was affected by culture conditions, and MICs were reduced in the presence of serum.

  16. 64 FR 9042 - New Vaccine Information Materials for Hepatitis B, Haemophilus influenzae type b (Hib), and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    1999-02-23

    ... children under 5 years old in the United States. Meningitis is an infection of the brain and spinal cord... Information Materials for Hepatitis B, Haemophilus influenzae type b (Hib), and Varicella (Chickenpox... vaccine information materials for the newly covered vaccines hepatitis B, Haemophilus influenzae type b...

  17. Nicotinamide Ribosyl Uptake Mutants in Haemophilus influenzae

    PubMed Central

    Herbert, Mark; Sauer, Elizabeta; Smethurst, Graeme; Kraiβ, Anita; Hilpert, Anna-Karina; Reidl, Joachim

    2003-01-01

    The gene for the nicotinamide riboside (NR) transporter (pnuC) was identified in Haemophilus influenzae. A pnuC mutant had only residual NR uptake and could survive in vitro with high concentrations of NR, but could not survive in vivo. PnuC may represent a target for the development of inhibitors for preventing H. influenzae disease. PMID:12933892

  18. Nicotinamide ribosyl uptake mutants in Haemophilus influenzae.

    PubMed

    Herbert, Mark; Sauer, Elizabeta; Smethurst, Graeme; Kraiss, Anita; Hilpert, Anna-Karina; Reidl, Joachim

    2003-09-01

    The gene for the nicotinamide riboside (NR) transporter (pnuC) was identified in Haemophilus influenzae. A pnuC mutant had only residual NR uptake and could survive in vitro with high concentrations of NR, but could not survive in vivo. PnuC may represent a target for the development of inhibitors for preventing H. influenzae disease.

  19. Haemophilus meningitis in an African neonate: time for active surveillance and institution of appropriate control measure.

    PubMed

    Adeboye, M A; Obasa, T O; Fadeyi, A; Adesiyun, O O; Mokuolu, O A

    2010-01-01

    Childhood routine immunization in Nigeria, like most developing nations, do not include vaccination against Haemophilus influenzae type b (Hib) infection. This is probably because infection with Hib is uncommon in children younger than two months due to passive acquisition of maternal antibodies which protects newborn till about four to six months of life. To illustrate a case of neonatal meningitis caused by Haemophilus influenzae and to highlight its other peculiarities. A 22-day old baby presented with excessive crying, refusal of feed, progressive abdominal distension, fever and vomiting. Besides clinical assessment, body fluids were cultured. The baby had tachypnoea (90 bpm), tachycardia (182 bpm), and tympanitic and hypoactive abdomen. The musculoskeletal and central nervous systems appeared clinically normal. Haemophilus influenzae was isolated by culture from the cerebrospinal fluid. The baby responded well to treatment with ceftriaxone and gentamycin. Neurological examination has remained normal after discharge for up to three months at follow-up visit. There is the need to provide serological and molecular facilities for typing Nigerian Haemophilus infulenzae strain(s) to enhance the development of appropriate vaccine that will be most suitable for prevention of infection due to this organism in Nigeria. However, presently available Haemophilus influenzae vaccine needs to be listed in the National Programme for Immunization (NPI) for the control of infections associated with this organism especially in childhood.

  20. Phylogenomic and Molecular Demarcation of the Core Members of the Polyphyletic Pasteurellaceae Genera Actinobacillus, Haemophilus, and Pasteurella

    PubMed Central

    Naushad, Sohail; Adeolu, Mobolaji; Goel, Nisha; Khadka, Bijendra; Al-Dahwi, Aqeel; Gupta, Radhey S.

    2015-01-01

    The genera Actinobacillus, Haemophilus, and Pasteurella exhibit extensive polyphyletic branching in phylogenetic trees and do not represent coherent clusters of species. In this study, we have utilized molecular signatures identified through comparative genomic analyses in conjunction with genome based and multilocus sequence based phylogenetic analyses to clarify the phylogenetic and taxonomic boundary of these genera. We have identified large clusters of Actinobacillus, Haemophilus, and Pasteurella species which represent the “sensu stricto” members of these genera. We have identified 3, 7, and 6 conserved signature indels (CSIs), which are specifically shared by sensu stricto members of Actinobacillus, Haemophilus, and Pasteurella, respectively. We have also identified two different sets of CSIs that are unique characteristics of the pathogen containing genera Aggregatibacter and Mannheimia, respectively. It is now possible to demarcate the genera Actinobacillus sensu stricto, Haemophilus sensu stricto, and Pasteurella sensu stricto on the basis of discrete molecular signatures. The other members of the genera Actinobacillus, Haemophilus, and Pasteurella that do not fall within the “sensu stricto” clades and do not contain these molecular signatures should be reclassified as other genera. The CSIs identified here also provide useful diagnostic targets for the identification of current and novel members of the indicated genera. PMID:25821780

  1. Chronic cutaneous ulcers secondary to Haemophilus ducreyi infection.

    PubMed

    Peel, Trisha N; Bhatti, Deepak; De Boer, Jim C; Stratov, Ivan; Spelman, Denis W

    2010-03-15

    Haemophilus ducreyi is a well recognised causative agent of genital ulcers and chancroid. We report two unusual cases of non-sexually transmitted H. ducreyi infection leading to chronic lower limb ulcers. Both patients were Australian expatriates visiting Australia from the Pacific Islands--one from Papua New Guinea and the other from Vanuatu.

  2. Nasopharyngeal and Adenoid Colonization by Haemophilus influenzae and Haemophilus parainfluenzae in Children Undergoing Adenoidectomy and the Ability of Bacterial Isolates to Biofilm Production

    PubMed Central

    Kosikowska, Urszula; Korona-Głowniak, Izabela; Niedzielski, Artur; Malm, Anna

    2015-01-01

    Abstract Haemophili are pathogenic or opportunistic bacteria often colonizing the upper respiratory tract mucosa. The prevalence of Haemophilus influenzae (with serotypes distribution), and H. parainfluenzae in the nasopharynx and/or the adenoid core in children with recurrent pharyngotonsillitis undergoing adenoidectomy was assessed. Haemophili isolates were investigated for their ability to biofilm production. Nasopharyngeal swabs and the adenoid core were collected from 164 children who underwent adenoidectomy (2–5 years old). Bacteria were identified by the standard methods. Serotyping of H. influenzae was performed using polyclonal and monoclonal antisera. Biofilm formation was detected spectrophotometrically using 96-well microplates and 0.1% crystal violet. Ninety seven percent (159/164) children who underwent adenoidectomy were colonized by Haemophilus spp. The adenoid core was colonized in 99.4% (158/159) children, whereas the nasopharynx in 47.2% (75/159) children (P < 0.0001). In 32% (51/159) children only encapsulated (typeable) isolates of H. influenzae were identified, in 22.6% (36/159) children only (nonencapsulated) H. influenzae NTHi (nonencapsulated) isolates were present, whereas 7.5% (12/159) children were colonized by both types. 14.5% (23/159) children were colonized by untypeable (rough) H. influenzae. In 22% (35/159) children H. influenzae serotype d was isolated. Totally, 192 isolates of H. influenzae, 96 isolates of H. parainfluenzae and 14 isolates of other Haemophilus spp. were selected. In 20.1% (32/159) children 2 or 3 phenotypically different isolates of the same species (H. influenzae or H. parainfluenzae) or serotypes (H. influenzae) were identified in 1 child. 67.2% (129/192) isolates of H. influenzae, 56.3% (54/96) isolates of H. parainfluenzae and 85.7% (12/14) isolates of other Haemophilus spp. were positive for biofilm production. Statistically significant differences (P = 0.0029) among H. parainfluenzae

  3. Comparative Genomic Analysis of Haemophilus haemolyticus and Nontypeable Haemophilus influenzae and a New Testing Scheme for Their Discrimination

    PubMed Central

    Hu, Fang; Rishishwar, Lavanya; Sivadas, Ambily; Mitchell, Gabriel J.; Jordan, I. King; Murphy, Timothy F.; Gilsdorf, Janet R.; Mayer, Leonard W.

    2016-01-01

    Haemophilus haemolyticus has been recently discovered to have the potential to cause invasive disease. It is closely related to nontypeable Haemophilus influenzae (NT H. influenzae). NT H. influenzae and H. haemolyticus are often misidentified because none of the existing tests targeting the known phenotypes of H. haemolyticus are able to specifically identify H. haemolyticus. Through comparative genomic analysis of H. haemolyticus and NT H. influenzae, we identified genes unique to H. haemolyticus that can be used as targets for the identification of H. haemolyticus. A real-time PCR targeting purT (encoding phosphoribosylglycinamide formyltransferase 2 in the purine synthesis pathway) was developed and evaluated. The lower limit of detection was 40 genomes/PCR; the sensitivity and specificity in detecting H. haemolyticus were 98.9% and 97%, respectively. To improve the discrimination of H. haemolyticus and NT H. influenzae, a testing scheme combining two targets (H. haemolyticus purT and H. influenzae hpd, encoding protein D lipoprotein) was also evaluated and showed 96.7% sensitivity and 98.2% specificity for the identification of H. haemolyticus and 92.8% sensitivity and 100% specificity for the identification of H. influenzae, respectively. The dual-target testing scheme can be used for the diagnosis and surveillance of infection and disease caused by H. haemolyticus and NT H. influenzae. PMID:27707939

  4. Haemophilus haemolyticus Interaction with Host Cells Is Different to Nontypeable Haemophilus influenzae and Prevents NTHi Association with Epithelial Cells

    PubMed Central

    Pickering, Janessa L.; Prosser, Amy; Corscadden, Karli J.; de Gier, Camilla; Richmond, Peter C.; Zhang, Guicheng; Thornton, Ruth B.; Kirkham, Lea-Ann S.

    2016-01-01

    Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that resides in the upper respiratory tract and contributes to a significant burden of respiratory related diseases in children and adults. Haemophilus haemolyticus is a respiratory tract commensal that can be misidentified as NTHi due to high levels of genetic relatedness. There are reports of invasive disease from H. haemolyticus, which further blurs the species boundary with NTHi. To investigate differences in pathogenicity between these species, we optimized an in vitro epithelial cell model to compare the interaction of 10 H. haemolyticus strains with 4 NTHi and 4 H. influenzae-like haemophili. There was inter- and intra-species variability but overall, H. haemolyticus had reduced capacity to attach to and invade nasopharyngeal and bronchoalveolar epithelial cell lines (D562 and A549) within 3 h when compared with NTHi. H. haemolyticus was cytotoxic to both cell lines at 24 h, whereas NTHi was not. Nasopharyngeal epithelium challenged with some H. haemolyticus strains released high levels of inflammatory mediators IL-6 and IL-8, whereas NTHi did not elicit an inflammatory response despite higher levels of cell association and invasion. Furthermore, peripheral blood mononuclear cells stimulated with H. haemolyticus or NTHi released similar and high levels of IL-6, IL-8, IL-10, IL-1β, and TNFα when compared with unstimulated cells but only NTHi elicited an IFNγ response. Due to the relatedness of H. haemolyticus and NTHi, we hypothesized that H. haemolyticus may compete with NTHi for colonization of the respiratory tract. We observed that in vitro pre-treatment of epithelial cells with H. haemolyticus significantly reduced NTHi attachment, suggesting interference or competition between the two species is possible and warrants further investigation. In conclusion, H. haemolyticus interacts differently with host cells compared to NTHi, with different immunostimulatory and cytotoxic

  5. In vitro selection of resistance in haemophilus influenzae by 4 quinolones and 5 beta-lactams.

    PubMed

    Clark, Catherine; Kosowska, Klaudia; Bozdogan, Bülent; Credito, Kim; Dewasse, Bonifacio; McGhee, Pamela; Jacobs, Michael R; Appelbaum, Peter C

    2004-05-01

    We tested abilities of ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin, amoxicillin, amoxicillin/clavulanate, cefixime, cefpodoxime, and cefdinir to select resistant mutants in 5 beta-lactamase positive and 5 beta-lactamase negative Haemophilus influenzae strains by single and multistep methodology. In multistep tests, amoxicillin, amoxicillin/clavulanate and cefpodoxime exposure did not cause >4-fold minimum inhibitory concentration (MIC) increase after 50 days. One mutant selected by cefdinir had one amino acid substitution (Gly490Glu) in PBP3 and became resistant to cefdinir. Cefixime exposure caused 8-fold MIC-increase in 1 strain with TEM but the mutant remained cefixime susceptible and had no alteration in PBP3 or TEM. Among 10 strains tested, ciprofloxacin, moxifloxacin, gatifloxacin, levofloxacin caused >4-fold MIC increase in 6, 6, 5, and 2 strain, respectively. Despite the increases in quinolone MICs, none of the mutants became resistant to quinolones by established criteria. Quinolone selected mutants had quindone resistance-determining region (QRDR) alterations in GyrA, GyrB, ParC, ParE. Four quinolone mutants had no QRDR alterations. Among beta-lactams cefdinir and cefixime selected one mutant each with higher MICs however amoxicillin, amoxicillin/clavulanate, and cefpodoxime exposure did not select resistant mutants.

  6. An animal source for the ROB-1 beta-lactamase of Haemophilus influenzae type b.

    PubMed

    Medeiros, A A; Levesque, R; Jacoby, G A

    1986-02-01

    The most common cause of ampicillin resistance in Haemophilus influenzae type b is production of TEM-1 beta-lactamase; however, a novel enzyme with a similar substrate profile but a quite different isoelectric point has also been described. This beta-lactamase, designated ROB-1, has not been found previously in any other organism. In a survey of 46 ampicillin-resistant H. influenzae type b isolates, we found a second human isolate that produces ROB-1 and discovered that ampicillin-resistant isolates of the porcine pathogen Haemophilus pleuropneumoniae also produced ROB-1. In both Haemophilus species ROB-1 production was determined by plasmids that had considerable DNA sequence homology. However, the ROB-1 and TEM-1 beta-lactamase genes were not related. Our findings suggest that this form of ampicillin resistance has an animal reservoir and that conditions fostering its prevalence in animal strains may play a role in the spread of resistance to human pathogens.

  7. Shielding of a lipooligosaccharide IgM epitope allows evasion of neutrophil-mediated killing of an invasive strain of nontypeable Haemophilus influenzae.

    PubMed

    Langereis, Jeroen D; Weiser, Jeffrey N

    2014-07-22

    Nontypeable Haemophilus influenzae is a frequent cause of noninvasive mucosal inflammatory diseases but may also cause invasive diseases, such as sepsis and meningitis, especially in children and the elderly. Infection by nontypeable Haemophilus influenzae is characterized by recruitment of neutrophilic granulocytes. Despite the presence of a large number of neutrophils, infections with nontypeable Haemophilus influenzae are often not cleared effectively by the antimicrobial activity of these immune cells. Herein, we examined how nontypeable Haemophilus influenzae evades neutrophil-mediated killing. Transposon sequencing (Tn-seq) was used on an isolate resistant to neutrophil-mediated killing to identify genes required for its survival in the presence of human neutrophils and serum, which provided a source of complement and antibodies. Results show that nontypeable Haemophilus influenzae prevents complement-dependent neutrophil-mediated killing by expression of surface galactose-containing oligosaccharide structures. These outer-core structures block recognition of an inner-core lipooligosaccharide epitope containing glucose attached to heptose HepIII-β1,2-Glc by replacement with galactose attached to HepIII or through shielding HepIII-β1,2-Glc by phase-variable attachment of oligosaccharide chain extensions. When the HepIII-β1,2-Glc-containing epitope is expressed and exposed, nontypeable Haemophilus influenzae is opsonized by naturally acquired IgM generally present in human serum and subsequently phagocytosed and killed by human neutrophils. Clinical nontypeable Haemophilus influenzae isolates containing galactose attached to HepIII that are not recognized by this IgM are more often found to cause invasive infections. Importance: Neutrophils are white blood cells that specialize in killing pathogens and are recruited to sites of inflammation. However, despite the presence of large numbers of neutrophils in the middle ear cavity and lungs of patients with

  8. [An adult case of haemophilus parainfluenzae bacteremia and meningitis].

    PubMed

    Kangas, Ida

    2010-01-04

    A case of bacteremia and meningitis caused by Haemophilus parainfluenzae in an adult patient without known immunodeficiency and normal complement system is presented. H. parainfluenzae has not previously been reported as the cause of meningitis in Denmark. Patients with invasive H. parainfluenzae infection should be examined for complement factor 7 defect.

  9. Impact of Haemophilus influenzae type b vaccination on the incidence of invasive Haemophilus influenzae disease in France, 15 years after its introduction.

    PubMed

    Georges, S; Lepoutre, A; Dabernat, H; Levy-Bruhl, D

    2013-09-01

    We assessed the impact of Haemophilus influenzae type b (Hib) vaccination, introduced in France in early 1993, on the incidence of invasive Haemophilus influenzae (Hi) disease up to 2008.The incidence of Hi meningitis fell from 0·9/100000 in 1991–1992 to 0·09/100 000 in 1996–2008,with a marked decline (96%) in children aged <5 years, including infants aged <3 months, from 12 to 0·4 /100 000. The incidence of invasive Hi disease also decreased in children aged <15 years from 6 to 0·7 /100 000, remained stable in the 15–64 years age group at about 0·5/100 000,and increased slightly from 2·0 to 2·4 /100 000 in persons aged >64 years. No emergence of non-encapsulated or encapsulated non-vaccine serotypes was observed. These findings confirm the major direct impact of Hib vaccination on the incidence of Hi invasive disease in children and the indirect benefit of vaccination for infants too young to be vaccinated.

  10. Comparative Genomic Analysis of Haemophilus haemolyticus and Nontypeable Haemophilus influenzae and a New Testing Scheme for Their Discrimination.

    PubMed

    Hu, Fang; Rishishwar, Lavanya; Sivadas, Ambily; Mitchell, Gabriel J; Jordan, I King; Murphy, Timothy F; Gilsdorf, Janet R; Mayer, Leonard W; Wang, Xin

    2016-12-01

    Haemophilus haemolyticus has been recently discovered to have the potential to cause invasive disease. It is closely related to nontypeable Haemophilus influenzae (NT H. influenzae). NT H. influenzae and H. haemolyticus are often misidentified because none of the existing tests targeting the known phenotypes of H. haemolyticus are able to specifically identify H. haemolyticus Through comparative genomic analysis of H. haemolyticus and NT H. influenzae, we identified genes unique to H. haemolyticus that can be used as targets for the identification of H. haemolyticus A real-time PCR targeting purT (encoding phosphoribosylglycinamide formyltransferase 2 in the purine synthesis pathway) was developed and evaluated. The lower limit of detection was 40 genomes/PCR; the sensitivity and specificity in detecting H. haemolyticus were 98.9% and 97%, respectively. To improve the discrimination of H. haemolyticus and NT H. influenzae, a testing scheme combining two targets (H. haemolyticus purT and H. influenzae hpd, encoding protein D lipoprotein) was also evaluated and showed 96.7% sensitivity and 98.2% specificity for the identification of H. haemolyticus and 92.8% sensitivity and 100% specificity for the identification of H. influenzae, respectively. The dual-target testing scheme can be used for the diagnosis and surveillance of infection and disease caused by H. haemolyticus and NT H. influenzae. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  11. Haemophilus parainfluenzae urethritis among homosexual men.

    PubMed

    Hsu, Meng-Shiuan; Wu, Mei-Yu; Lin, Tsui-Hsien; Liao, Chun-Hsing

    2015-08-01

    Haemophilus parainfluenzae is a common inhabitant of the human upper respiratory tract of the normal oral microflora. We report three men who had been having unprotected sex with men (MSM) and subsequently acquired H. parainfluenzae urethritis, which was confirmed by 16S rRNA gene sequencing analysis. Two men were treated with ceftriaxone and doxycycline, and the third man was treated with clarithromycin. All three patients responded to treatment. This case series highlights the potential role of H. parainfluenzae as a sexually transmitted genitourinary pathogen. Copyright © 2012. Published by Elsevier B.V.

  12. Quorum signaling and sensing by nontypeable Haemophilus influenzae.

    PubMed

    Swords, W Edward

    2012-01-01

    Quorum signals are diffusible factors produced by bacteria that coordinate communal responses. For nontypeable Haemophilus influenzae (NTHi), a series of recent papers indicate that production and sensing of quorum signals are determinants of biofilm formation/maturation and persistence in vivo. In this mini-review I will summarize the current knowledge about quorum signaling/sensing by this organism, and identify specific topics for additional study.

  13. Quorum signaling and sensing by nontypeable Haemophilus influenzae

    PubMed Central

    Swords, W. Edward

    2012-01-01

    Quorum signals are diffusible factors produced by bacteria that coordinate communal responses. For nontypeable Haemophilus influenzae (NTHi), a series of recent papers indicate that production and sensing of quorum signals are determinants of biofilm formation/maturation and persistence in vivo. In this mini-review I will summarize the current knowledge about quorum signaling/sensing by this organism, and identify specific topics for additional study. PMID:22919689

  14. Inhibitory effect of 1,2,4-triazole-ciprofloxacin hybrids on Haemophilus parainfluenzae and Haemophilus influenzae biofilm formation in vitro under stationary conditions.

    PubMed

    Kosikowska, Urszula; Andrzejczuk, Sylwia; Plech, Tomasz; Malm, Anna

    2016-10-01

    Haemophilus parainfluenzae and Haemophilus influenzae, upper respiratory tract microbiota representatives, are able to colonize natural and artificial surfaces as biofilm. The aim of the present study was to assay the effect of ten 1,2,4-triazole-ciprofloxacin hybrids on planktonic or biofilm-forming haemophili cells in vitro under stationary conditions on the basis of MICs (minimal inhibitory concentrations) and MBICs (minimal biofilm inhibitory concentrations). In addition, anti-adhesive properties of these compounds were examined. The reference strains of H. parainfluenzae and H. influenzae were included. The broth microdilution microtiter plate (MTP) method with twofold dilution of the compounds, or ciprofloxacin (reference agent) in 96-well polystyrene microplates, was used. The optical density (OD) reading was made spectrophotometrically at a wavelength of 570 nm (OD570) both to measure bacterial growth and to detect biofilm-forming cells under the same conditions with 0.1% crystal violet. The following values of parameters were estimated for 1,2,4-triazole-ciprofloxacin hybrids - MIC = 0.03-15.63 mg/L, MBIC = 0.03-15.63 mg/L, MBIC/MIC = 0.125-8, depending on the compound, and for ciprofloxacin - MIC = 0.03-0.06 mg/L, MBIC = 0.03-0.12 mg/L, MBIC/MIC = 1-2. The observed strong anti-adhesive properties (95-100% inhibition) of the tested compounds were reversible during long-term incubation at subinhibitory concentrations. Thus, 1,2,4-triazole-ciprofloxacin hybrids may be considered as starting compounds for designing improved agents not only against planktonic but also against biofilm-forming Haemophilus spp. cells. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  15. Clinical and microbiological features of Haemophilus influenzae vulvovaginitis in young girls

    PubMed Central

    Cox, R A; Slack, M P E

    2002-01-01

    Aims: To define the clinical and microbiological features of vulvovaginitis in prepubertal girls whose genital swabs yielded Haemophilus influenzae. Methods: Laboratory based study and retrospective collection of clinical data from the requesting doctors. Results: Thirty eight isolates of non-capsulate Haemophilus influenzae and one of H parainfluenzae were isolated from 32 girls aged 18 months to 11 years. No other pathogens, such as β haemolytic streptococci or yeasts, were present with H influenzae. The most common biotype was biotype II, comprising 57% of the 26 isolates biotyped. Six children had more than one episode of vulvovaginitis caused by H influenzae and a total of 14 children had recurrent vaginal symptoms. Conclusion: Children who have H influenzae vulvovaginitis are at risk of recurrent symptoms. Biotype II is the one most commonly associated with this condition. PMID:12461068

  16. Virulence, transmission, and heterologous protection of four isolates of Haemophilus parasuis

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis causes Glässer's disease, a syndrome of polyserositis, meningitis, and arthritis in swine. Previous studies with H. parasuis have revealed virulence disparity among isolates and inconsistent heterologous protection. In this study, virulence, direct transmission, and heterologous...

  17. Invasive Disease Caused by Nontypeable Haemophilus influenzae

    PubMed Central

    de Jonge, Marien I.

    2015-01-01

    The incidence of severe Haemophilus influenza infections, such as sepsis and meningitis, has declined substantially since the introduction of the H. influenzae serotype b vaccine. However, the H. influenzae type b vaccine fails to protect against nontypeable H. influenzae strains, which have become increasingly frequent causes of invasive disease, especially among children and the elderly. We summarize recent literature supporting the emergence of invasive nontypeable H. influenzae and describe mechanisms that may explain its increasing prevalence over the past 2 decades. PMID:26407156

  18. Delineation of the Species Haemophilus influenzae by Phenotype, Multilocus Sequence Phylogeny, and Detection of Marker Genes▿ †

    PubMed Central

    Nørskov-Lauritsen, Niels; Overballe, Merete D.; Kilian, Mogens

    2009-01-01

    To obtain more information on the much-debated definition of prokaryotic species, we investigated the borders of Haemophilus influenzae by comparative analysis of H. influenzae reference strains with closely related bacteria including strains assigned to Haemophilus haemolyticus, cryptic genospecies biotype IV, and the never formally validated species “Haemophilus intermedius”. Multilocus sequence phylogeny based on six housekeeping genes separated a cluster encompassing the type and the reference strains of H. influenzae from 31 more distantly related strains. Comparison of 16S rRNA gene sequences supported this delineation but was obscured by a conspicuously high number of polymorphic sites in many of the strains that did not belong to the core group of H. influenzae strains. The division was corroborated by the differential presence of genes encoding H. influenzae adhesion and penetration protein, fuculokinase, and Cu,Zn-superoxide dismutase, whereas immunoglobulin A1 protease activity or the presence of the iga gene was of limited discriminatory value. The existence of porphyrin-synthesizing strains (“H. intermedius”) closely related to H. influenzae was confirmed. Several chromosomally encoded hemin biosynthesis genes were identified, and sequence analysis showed these genes to represent an ancestral genotype rather than recent transfers from, e.g., Haemophilus parainfluenzae. Strains previously assigned to H. haemolyticus formed several separate lineages within a distinct but deeply branching cluster, intermingled with strains of “H. intermedius” and cryptic genospecies biotype IV. Although H. influenzae is phenotypically more homogenous than some other Haemophilus species, the genetic diversity and multicluster structure of strains traditionally associated with H. influenzae make it difficult to define the natural borders of that species. PMID:19060144

  19. Comparative virulence and genomic analysis of 10 strains of Haemophilus parasuis

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis is the cause of Glasser's disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. An enormous difference exists in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to asympto...

  20. Haemophilus influenzae Type a Meningitis in Immunocompetent Child, Oman, 2015.

    PubMed

    Sawardekar, Kiran P

    2017-07-01

    Meningitis caused by Haemophilus influenzae type b (Hib) was eliminated in Oman after the introduction of Hib vaccine in 2001. However, a case of H. influenzae type a meningitis was diagnosed in a child from Oman in 2015, which highlights the need to monitor the incidence of invasive non-Hib H. influenzae disease.

  1. Duplex Quantitative PCR Assay for Detection of Haemophilus influenzae That Distinguishes Fucose- and Protein D-Negative Strains

    PubMed Central

    de Gier, Camilla; Pickering, Janessa L.; Richmond, Peter C.; Thornton, Ruth B.

    2016-01-01

    We have developed a specific Haemophilus influenzae quantitative PCR (qPCR) that also identifies fucose-negative and protein D-negative strains. Analysis of 100 H. influenzae isolates, 28 Haemophilus haemolyticus isolates, and 14 other bacterial species revealed 100% sensitivity (95% confidence interval [CI], 96% to 100%) and 100% specificity (95% CI, 92% to 100%) for this assay. The evaluation of 80 clinical specimens demonstrated a strong correlation between semiquantitative culture and the qPCR (P < 0.001). PMID:27335148

  2. Bacterial meningitis and Haemophilus influenzae type b conjugate vaccine, Malawi.

    PubMed

    McCormick, David W; Molyneux, Elizabeth M

    2011-04-01

    A retrospective database review showed that Haemophilus influenzae type b conjugate vaccine decreased the annual number of cases of H. influenzae type b meningitis in children in Blantyre, Malawi. Among young bacterial meningitis patients, HIV prevalence was high (36.7% during 1997-2009), and pneumococcus was the most common etiologic agent (57% in 2009).

  3. Haemophilus influenzae Type a Meningitis in Immunocompetent Child, Oman, 2015

    PubMed Central

    2017-01-01

    Meningitis caused by Haemophilus influenzae type b (Hib) was eliminated in Oman after the introduction of Hib vaccine in 2001. However, a case of H. influenzae type a meningitis was diagnosed in a child from Oman in 2015, which highlights the need to monitor the incidence of invasive non-Hib H. influenzae disease. PMID:28628438

  4. Vaccine-induced waning of Haemophilus influenzae empyema and meningitis, Angola.

    PubMed

    Peltola, Heikki; Pelkonen, Tuula; Bernardino, Luis; Monteiro, Lurdes; Silvestre, Silvia da Conceição; Anjos, Elizabete; Cruzeiro, Manuel Leite; Pitkäranta, Anne; Roine, Irmeli

    2014-11-01

    In Angola during 2003-2012, we detected Haemophilus influenzae in 18% of 2,634 and 26% of 2,996 bacteriologically positive pleural or cerebrospinal fluid samples, respectively, from children. After vaccination launch in 2006, H. influenzae empyema declined by 83% and meningitis by 86%. Severe H. influenzae pneumonia and meningitis are preventable by vaccination.

  5. Direct Whole-Genome Sequencing of Cutaneous Strains of Haemophilus ducreyi

    PubMed Central

    Fookes, Maria; Wagner, Josef; Ghinai, Rosanna; Sokana, Oliver; Sarkodie, Yaw-Adu; Solomon, Anthony W.; Mabey, David C.W.; Thomson, Nicholas R.

    2018-01-01

    Haemophilus ducreyi, which causes chancroid, has emerged as a cause of pediatric skin disease. Isolation of H. ducreyi in low-income settings is challenging, limiting phylogenetic investigation. Next-generation sequencing demonstrates that cutaneous strains arise from class I and II H. ducreyi clades and that class II may represent a distinct subspecies. PMID:29553314

  6. ABA-insensitive3, ABA-insensitive5, and DELLAs Interact to activate the expression of SOMNUS and other high-temperature-inducible genes in imbibed seeds in Arabidopsis.

    PubMed

    Lim, Soohwan; Park, Jeongmoo; Lee, Nayoung; Jeong, Jinkil; Toh, Shigeo; Watanabe, Asuka; Kim, Junghyun; Kang, Hyojin; Kim, Dong Hwan; Kawakami, Naoto; Choi, Giltsu

    2013-12-01

    Seeds monitor the environment to germinate at the proper time, but different species respond differently to environmental conditions, particularly light and temperature. In Arabidopsis thaliana, light promotes germination but high temperature suppresses germination. We previously reported that light promotes germination by repressing SOMNUS (SOM). Here, we examined whether high temperature also regulates germination through SOM and found that high temperature activates SOM expression. Consistent with this, som mutants germinated more frequently than the wild type at high temperature. The induction of SOM mRNA at high temperature required abscisic acid (ABA) and gibberellic acid biosynthesis, and ABA-insensitive3 (ABI3), ABI5, and DELLAs positively regulated SOM expression. Chromatin immunoprecipitation assays indicated that ABI3, ABI5, and DELLAs all target the SOM promoter. At the protein level, ABI3, ABI5, and DELLAs all interact with each other, suggesting that they form a complex on the SOM promoter to activate SOM expression at high temperature. We found that high-temperature-inducible genes frequently have RY motifs and ABA-responsive elements in their promoters, some of which are targeted by ABI3, ABI5, and DELLAs in vivo. Taken together, our data indicate that ABI3, ABI5, and DELLAs mediate high-temperature signaling to activate the expression of SOM and other high-temperature-inducible genes, thereby inhibiting seed germination.

  7. Effects of various media on the activity of NXL103 (formerly XRP 2868), a new oral streptogramin, against Haemophilus influenzae.

    PubMed

    Pankuch, Glenn A; Hoellman, Dianne; Bryskier, André; Lowther, John; Appelbaum, Peter C

    2006-11-01

    The activity of NXL103 against 108 strains of Haemophilus influenzae was tested using Haemophilus test media (HTM) obtained from various sources. With the exception of those obtained with stored HTM, MICs did not differ significantly, with MIC(50) and MIC(90) values of 0.5 and 0.5 to 1 microg/ml, respectively, in each medium.

  8. Vaccine-Induced Waning of Haemophilus influenzae Empyema and Meningitis, Angola

    PubMed Central

    Peltola, Heikki; Bernardino, Luis; Monteiro, Lurdes; Silvestre, Silvia da Conceição; Anjos, Elizabete; Cruzeiro, Manuel Leite; Pitkäranta, Anne; Roine, Irmeli

    2014-01-01

    In Angola during 2003–2012, we detected Haemophilus influenzae in 18% of 2,634 and 26% of 2,996 bacteriologically positive pleural or cerebrospinal fluid samples, respectively, from children. After vaccination launch in 2006, H. influenzae empyema declined by 83% and meningitis by 86%. Severe H. influenzae pneumonia and meningitis are preventable by vaccination. PMID:25340259

  9. Bacterial Meningitis and Haemophilus influenzae Type b Conjugate Vaccine, Malawi

    PubMed Central

    Molyneux, Elizabeth M.

    2011-01-01

    A retrospective database review showed that Haemophilus influenzae type b conjugate vaccine decreased the annual number of cases of H. influenzae type b meningitis in children in Blantyre, Malawi. Among young bacterial meningitis patients, HIV prevalence was high (36.7% during 1997–2009), and pneumococcus was the most common etiologic agent (57% in 2009). PMID:21470461

  10. Haemophilus ducreyi associated with skin ulcers among children, Solomon Islands.

    PubMed

    Marks, Michael; Chi, Kai-Hua; Vahi, Ventis; Pillay, Allan; Sokana, Oliver; Pavluck, Alex; Mabey, David C; Chen, Cheng Y; Solomon, Anthony W

    2014-10-01

    During a survey of yaws prevalence in the Solomon Islands, we collected samples from skin ulcers of 41 children. Using PCR, we identified Haemophilus ducreyi infection in 13 (32%) children. PCR-positive and PCR-negative ulcers were phenotypically indistinguishable. Emergence of H. ducreyi as a cause of nongenital ulcers may affect the World Health Organization's yaws eradication program.

  11. Naturally Acquired Antibodies against Haemophilus influenzae Type a in Aboriginal Adults, Canada

    PubMed Central

    Nix, Eli B.; Williams, Kylie; Cox, Andrew D.; St. Michael, Frank; Romero-Steiner, Sandra; Schmidt, Daniel S.; McCready, William G.

    2015-01-01

    In the post-Haemophilus influenzae type b (Hib) vaccine era that began in the 1980's, H. influenzae type a (Hia) emerged as a prominent cause of invasive disease in North American Aboriginal populations. To test whether a lack of naturally acquired antibodies may underlie increased rates of invasive Hia disease, we compared serum bactericidal activity against Hia and Hib and IgG and IgM against capsular polysaccharide between Canadian Aboriginal and non-Aboriginal healthy and immunocompromised adults. Both healthy and immunocompromised Aboriginal adults exhibited significantly higher bactericidal antibody titers against Hia than did non-Aboriginal adults (p = 0.042 and 0.045 respectively), with no difference in functional antibody activity against Hib. IgM concentrations against Hia were higher than IgG in most study groups; the inverse was true for antibody concentrations against Hib. Our results indicate that Aboriginal adults possess substantial serum bactericidal activity against Hia that is mostly due to IgM antibodies. The presence of sustained IgM against Hia suggests recent Hia exposure. PMID:25626129

  12. Invasive Haemophilus influenzae Infection in Patients With Cancer.

    PubMed

    Singh, Vivek; Nanjappa, Sowmya; Pabbathi, Smitha; Greene, John N

    2017-01-01

    A major cause of morbidity and mortality in patients with cancer is infection. Since the introduction of the Haemophilus influenzae type b (Hib) vaccine in the United States in the 1990s, invasive H influenzae infection has become less common. We report on 5 patients with cancer and invasive H influenzae infection. A literature review was also performed of the dominant Haemophilus subtype and the clinical features associated with the infection and concomitant cancer. Of the 17 cases found in the literature, had hematological malignancies and 1 case each had thymoma, schwannoma, teratoma, and pancreatic, Merkel cell, pharyngeal, laryngeal, and rectal carcinomas. Two cases occurred with AIDS and Kaposi sarcoma. Pneumonia with bacteremia was seen in 8 cases, whereas pleuritis, neck cellulitis, septic arthritis, meningitis, and mediastinitis were diagnosed in the others. No focus of infection was identified in 2 cases. Nontypable H influenzae (NTHi) occurred in 4 cases, and Hib was isolated in 2 cases; serotyping was not reported in the others. Leukocytosis occurred in 7 cases and lymphopenia in 3; no cases presented with neutropenia. Four isolates were positive for beta-lactamase. Susceptibility data were unavailable in 5 case patients. Among serotyped cases, 67% were of the NTHi strain - a finding consistent with the change in the epidemiology of H influenzae since the introduction of the Hib vaccine.

  13. Treatment of Haemophilus bacteremia with benzylpenicillin is associated with increased (30-day) mortality.

    PubMed

    Thønnings, Sara; Østergaard, Christian

    2012-07-09

    Optimal antibiotic treatment strategies of Haemophilus infections are still needed. Therefore, 30-day case fatality rate (CFR) of Haemophilus bacteremia and efficacy of various antibiotic treatment regimes were studied. All episodes of Haemophilus bacteremia in the former Copenhagen County during the period 2000-9 were included in the study. Clinical and biochemical findings and outcome were collected retrospectively from medical records. 105 consecutive episodes were identified (median age: 69 years, with only 4 children <16 years), 72% were due to non-typeable -, 16% to typeable H. influenzae, and 11% to other Haemophilus species. Pneumonia was the most common primary focus (in 48%), and 58% of the patients had Charlson comorbidity index > 1. Definitive antibiotic therapy was in 26 cases benzylpenicillin, in 12 cases aminopenicillins, in 50 cases cefuroxime and in 16 cases broadspectrum antibiotics, whereas 1 palliative case died without start of therapy. Whereas the use of broadspectrum antibiotics was related to the severity of the disease (admittance to ICU, need for assisted ventilation or hemodialysis, septic shock), no significant difference in clinical features was demonstrated for therapy with benzylpenicillin, aminopenicillin or cefuroxime, except benzylpenicillin was rarely administered to immunosuppressed patients. The CFR was 22% (23/105). The choice of empiric antibiotic therapy was not significantly associated with mortality (adequate vs. inadequate treatment: 23% (21/93) vs. 17% (2/12), respectively, P > 0.05). In contrast, definite antibiotic therapy with cefuroxime or aminopenicillins resulted in a significantly lower CFR than treatment with benzylpenicillin (12% (6/50) or 0% (0/12) vs. 39% (10/26), respectively, Log rank test P < 0.02). When adjustments were made for other identified risk factors in bivariate logistic regression analysis, treatment with cefuroxime was still were found to be associated with a significantly lower

  14. Treatment of Haemophilus bacteremia with benzylpenicillin is associated with increased (30-day) mortality

    PubMed Central

    2012-01-01

    Background Optimal antibiotic treatment strategies of Haemophilus infections are still needed. Therefore, 30-day case fatality rate (CFR) of Haemophilus bacteremia and efficacy of various antibiotic treatment regimes were studied. Methods All episodes of Haemophilus bacteremia in the former Copenhagen County during the period 2000-9 were included in the study. Clinical and biochemical findings and outcome were collected retrospectively from medical records. Results 105 consecutive episodes were identified (median age: 69 years, with only 4 children <16 years), 72% were due to non-typeable -, 16% to typeable H. influenzae, and 11% to other Haemophilus species. Pneumonia was the most common primary focus (in 48%), and 58% of the patients had Charlson comorbidity index > 1. Definitive antibiotic therapy was in 26 cases benzylpenicillin, in 12 cases aminopenicillins, in 50 cases cefuroxime and in 16 cases broadspectrum antibiotics, whereas 1 palliative case died without start of therapy. Whereas the use of broadspectrum antibiotics was related to the severity of the disease (admittance to ICU, need for assisted ventilation or hemodialysis, septic shock), no significant difference in clinical features was demonstrated for therapy with benzylpenicillin, aminopenicillin or cefuroxime, except benzylpenicillin was rarely administered to immunosuppressed patients. The CFR was 22% (23/105). The choice of empiric antibiotic therapy was not significantly associated with mortality (adequate vs. inadequate treatment: 23% (21/93) vs. 17% (2/12), respectively, P > 0.05). In contrast, definite antibiotic therapy with cefuroxime or aminopenicillins resulted in a significantly lower CFR than treatment with benzylpenicillin (12% (6/50) or 0% (0/12) vs. 39% (10/26), respectively, Log rank test P < 0.02). When adjustments were made for other identified risk factors in bivariate logistic regression analysis, treatment with cefuroxime was still were found to be associated

  15. Effects of Various Media on the Activity of NXL103 (Formerly XRP 2868), a New Oral Streptogramin, against Haemophilus influenzae

    PubMed Central

    Pankuch, Glenn A.; Hoellman, Dianne; Bryskier, André; Lowther, John; Appelbaum, Peter C.

    2006-01-01

    The activity of NXL103 against 108 strains of Haemophilus influenzae was tested using Haemophilus test media (HTM) obtained from various sources. With the exception of those obtained with stored HTM, MICs did not differ significantly, with MIC50 and MIC90 values of 0.5 and 0.5 to 1 μg/ml, respectively, in each medium. PMID:17065630

  16. Antimicrobial Susceptibility of Haemophilus parainfluenzae

    PubMed Central

    Mayo, Joan B.; McCarthy, Laurence R.

    1977-01-01

    Fifty random clinical isolates of Haemophilus parainfluenzae were tested for their susceptibility to 10 antibiotics by a microtiter broth dilution method. Three of the strains tested were resistant to ampicillin, whereas eight were resistant to tetracycline. All strains tested were susceptible to chloramphenicol, kanamycin, gentamicin, cephalothin, and colistin. The ranges of minimal inhibitory concentrations for the three remaining antibiotics were: 0.5 to ≥128 μg of penicillin G per ml, 0.03 to 4 μg of carbenicillin per ml, and 1 to 16 μg of erythromycin per ml. Elevated minimal inhibitory concentrations for penicillin and carbenicillin were noted for the three ampicillin-resistant strains. Tests for beta-lactamase production demonstrated the presence of this enzyme in each of the three ampicillin-resistant strains. PMID:587028

  17. Comparative Analyses of the Lipooligosaccharides from Nontypeable Haemophilus influenzae and Haemophilus haemolyticus Show Differences in Sialic Acid and Phosphorylcholine Modifications

    PubMed Central

    Post, Deborah M. B.; Ketterer, Margaret R.; Coffin, Jeremy E.; Reinders, Lorri M.; Munson, Robert S.; Bair, Thomas; Murphy, Timothy F.; Foster, Eric D.; Gibson, Bradford W.

    2016-01-01

    Haemophilus haemolyticus and nontypeable Haemophilus influenzae (NTHi) are closely related upper airway commensal bacteria that are difficult to distinguish phenotypically. NTHi causes upper and lower airway tract infections in individuals with compromised airways, while H. haemolyticus rarely causes such infections. The lipooligosaccharide (LOS) is an outer membrane component of both species and plays a role in NTHi pathogenesis. In this study, comparative analyses of the LOS structures and corresponding biosynthesis genes were performed. Mass spectrometric and immunochemical analyses showed that NTHi LOS contained terminal sialic acid more frequently and to a higher extent than H. haemolyticus LOS did. Genomic analyses of 10 strains demonstrated that H. haemolyticus lacked the sialyltransferase genes lic3A and lic3B (9/10) and siaA (10/10), but all strains contained the sialic acid uptake genes siaP and siaT (10/10). However, isothermal titration calorimetry analyses of SiaP from two H. haemolyticus strains showed a 3.4- to 7.3-fold lower affinity for sialic acid compared to that of NTHi SiaP. Additionally, mass spectrometric and immunochemical analyses showed that the LOS from H. haemolyticus contained phosphorylcholine (ChoP) less frequently than the LOS from NTHi strains. These differences observed in the levels of sialic acid and ChoP incorporation in the LOS structures from H. haemolyticus and NTHi may explain some of the differences in their propensities to cause disease. PMID:26729761

  18. Typing of Haemophilus influenzae by Coagglutination and Conventional Slide Agglutination

    PubMed Central

    Shively, Roxanne G.; Shigel, Janet T.; Peterson, Ellena M.; De La Maza, Luis M.

    1981-01-01

    Coagglutination was compared with conventional slide agglutination for the typing of 297 clinical isolates of Haemophilus sp. A 100% correlation was found with the H. influenzae type b isolates. Coagglutination showed no false-positive reactions with the nontypable strains of H. influenzae and H. parainfluenzae isolates; however, conventional slide agglutination exhibited many false-positive and non-interpretable reactions. PMID:6977555

  19. Haemophilus ducreyi Associated with Skin Ulcers among Children, Solomon Islands

    PubMed Central

    Chi, Kai-Hua; Vahi, Ventis; Pillay, Allan; Sokana, Oliver; Pavluck, Alex; Mabey, David C.; Chen, Cheng Y.; Solomon, Anthony W.

    2014-01-01

    During a survey of yaws prevalence in the Solomon Islands, we collected samples from skin ulcers of 41 children. Using PCR, we identified Haemophilus ducreyi infection in 13 (32%) children. PCR-positive and PCR-negative ulcers were phenotypically indistinguishable. Emergence of H. ducreyi as a cause of nongenital ulcers may affect the World Health Organization’s yaws eradication program. PMID:25271477

  20. Necrotizing fasciitis caused by Haemophilus influenzae type b in a patient with rectal cancer treated with combined bevacizumab and chemotherapy: a case report.

    PubMed

    Ugai, Tomotaka; Norizuki, Masataro; Mikawa, Takahiro; Ohji, Goh; Yaegashi, Makito

    2014-04-12

    Recently, necrotizing fasciitis has been reported in patients treated with bevacizumab, usually secondary to wound healing complications, gastrointestinal perforations, or fistula formation. The risk of invasive Haemophilus influenzae type b infection is significantly increased in immunocompromised hosts. However, necrotizing fasciitis due to Haemophilus influenzae type b in a patient treated with combined bevacizumab and chemotherapy has not been previously reported. A 59-year-old woman was admitted to the intensive care unit after sudden onset of fever, chills, and right thigh pain. She received chemotherapy with fluorouracil, irinotecan, and bevacizumab for colon cancer 10 days prior to admission. The advancing erythematous margin and her worsening clinical condition prompted us to suspect necrotizing fasciitis and consult the orthopedics department for a fascia biopsy and debridement. Surgical exploration revealed a murky dishwater-colored pus exudate from the incision site and the lack of a shiny appearance of the fascia that also suggested necrotizing fasciitis. After 2 days, the final results of the blood and exudate cultures confirmed the presence of Haemophilus influenzae type b. A diagnosis of necrotizing fasciitis due to Haemophilus influenzae type b was made. The patient required recurrent surgical debridement and drainage, but she recovered from the septic shock. We report a case of necrotizing fasciitis due to Haemophilus influenzae type b in a patient without injury and with rectal cancer treated with combined bevacizumab and chemotherapy. Physicians should consider invasive Haemophilus influenzae type b disease in the presence of necrotizing fasciitis in patients treated with this combined treatment modality.

  1. Penicillin-binding proteins in Haemophilus influenzae.

    PubMed Central

    Makover, S D; Wright, R; Telep, E

    1981-01-01

    The penicillin-binding proteins (PBPs) of Haemophilus influenzae were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Eight major PBPs, ranging in molecular weights from 90,000 to 27,000, were detected. The pattern of molecular weights was different from that determined fro Escherichia coli or Pseudomonas aeruginosa. A study on the binding of several beta-lactam antibodies to the PBPs at their minimal inhibitory concentrations and at lower and higher concentrations revealed that all had highest affinity for PBP 2. Amdinocillin (mecillinam) was an exception; it had highest affinity for PBP 3. The morphological effects of several penicillins, cephalosporins, and amdinocillin on H. influenzae were similar to those reported for E. coli. Images PMID:6972731

  2. ABA-INSENSITIVE3, ABA-INSENSITIVE5, and DELLAs Interact to Activate the Expression of SOMNUS and Other High-Temperature-Inducible Genes in Imbibed Seeds in Arabidopsis[W

    PubMed Central

    Lim, Soohwan; Park, Jeongmoo; Lee, Nayoung; Jeong, Jinkil; Toh, Shigeo; Watanabe, Asuka; Kim, Junghyun; Kang, Hyojin; Kim, Dong Hwan; Kawakami, Naoto; Choi, Giltsu

    2013-01-01

    Seeds monitor the environment to germinate at the proper time, but different species respond differently to environmental conditions, particularly light and temperature. In Arabidopsis thaliana, light promotes germination but high temperature suppresses germination. We previously reported that light promotes germination by repressing SOMNUS (SOM). Here, we examined whether high temperature also regulates germination through SOM and found that high temperature activates SOM expression. Consistent with this, som mutants germinated more frequently than the wild type at high temperature. The induction of SOM mRNA at high temperature required abscisic acid (ABA) and gibberellic acid biosynthesis, and ABA-INSENSITIVE3 (ABI3), ABI5, and DELLAs positively regulated SOM expression. Chromatin immunoprecipitation assays indicated that ABI3, ABI5, and DELLAs all target the SOM promoter. At the protein level, ABI3, ABI5, and DELLAs all interact with each other, suggesting that they form a complex on the SOM promoter to activate SOM expression at high temperature. We found that high-temperature-inducible genes frequently have RY motifs and ABA-responsive elements in their promoters, some of which are targeted by ABI3, ABI5, and DELLAs in vivo. Taken together, our data indicate that ABI3, ABI5, and DELLAs mediate high-temperature signaling to activate the expression of SOM and other high-temperature-inducible genes, thereby inhibiting seed germination. PMID:24326588

  3. Whole-Genome Sequences of Nonencapsulated Haemophilus influenzae Strains Isolated in Italy

    PubMed Central

    Giufrè, Maria; De Chiara, Matteo; Censini, Stefano; Guidotti, Silvia; Torricelli, Giulia; De Angelis, Gabriella; Cardines, Rita; Pizza, Mariagrazia; Muzzi, Alessandro; Soriani, Marco

    2015-01-01

    Haemophilus influenzae is an important human pathogen involved in invasive disease. Here, we report the whole-genome sequences of 11 nonencapsulated H. influenzae (ncHi) strains isolated from both invasive disease and healthy carriers in Italy. This genomic information will enrich our understanding of the molecular basis of ncHi pathogenesis. PMID:25814593

  4. Potential use of outer membrane proteins as subunit vaccines against Haemophilus parasuis

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis is a Gram-negative bacterium belonging to the Pasteurellaceae family that causes Glässer's disease in pigs, a disease characterized by polyserositis, meningitis and arthritis. There are at least 15 serotypes of H. parasuis and vaccines are largely limited to bacterins that provi...

  5. Haemophilus influenzae type b meningitis in a vaccinated and immunocompetent child.

    PubMed

    Almeida, Ana F; Trindade, Eunice; B Vitor, Artur; Tavares, Margarida

    Invasive Haemophilus influenzae type b (Hib) disease decreased dramatically after the introduction of conjugate vaccine in routine immunization schedules. We report a case of a fifteen-months-old girl, previously healthy and vaccinated, admitted in the emergency room with fever and vomiting. She was irritable and the Brudzinski's sign was positive. The cerebrospinal fluid (CSF) analysis showed pleocytosis and high protein level. Empiric intravenous antibiotics (ceftriaxone and vancomycin) were administered for suspected bacterial meningitis during 10 days. Serotyping of the Haemophilus influenzae strain found in CSF revealed a serotype b. After one year of follow-up no Hib meningitis sequelae were noted. Despite vaccination compliance and absence of risk factors, invasive Hib disease can occur due to vaccine failure. Efforts to keep the low incidence of invasive Hib disease should be directed to the maintenance of high vaccination coverage rates, combined with the notification and surveillance strategies already implemented in each country. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  6. The Lung Immune Response to Nontypeable Haemophilus influenzae (Lung Immunity to NTHi)

    PubMed Central

    King, Paul T.; Sharma, Roleen

    2015-01-01

    Haemophilus influenzae is divided into typeable or nontypeable strains based on the presence or absence of a polysaccharide capsule. The typeable strains (such as type b) are an important cause of systemic infection, whilst the nontypeable strains (designated as NTHi) are predominantly respiratory mucosal pathogens. NTHi is present as part of the normal microbiome in the nasopharynx, from where it may spread down to the lower respiratory tract. In this context it is no longer a commensal and becomes an important respiratory pathogen associated with a range of common conditions including bronchitis, bronchiectasis, pneumonia, and particularly chronic obstructive pulmonary disease. NTHi induces a strong inflammatory response in the respiratory tract with activation of immune responses, which often fail to clear the bacteria from the lung. This results in recurrent/persistent infection and chronic inflammation with consequent lung pathology. This review will summarise the current literature about the lung immune response to nontypeable Haemophilus influenzae, a topic that has important implications for patient management. PMID:26114124

  7. Nucleotide Sequences of Genes Coding for Fimbrial Proteins in a Cryptic Genospecies of Haemophilus spp. Isolated from Neonatal and Genital Tract Infections

    PubMed Central

    Gousset, Nathalie; Rosenau, Agnes; Sizaret, Pierre-Yves; Quentin, Roland

    1999-01-01

    Nineteen isolates belonging to a cryptic genospecies of Haemophilus (referred to here as genital strains) isolated from genital tract infections (6 strains) and from neonatal infections (13 strains) were studied for fimbrial genes. Sixteen strains exhibit peritrichous fimbriae observed by electron microscopy. By PCR with primers corresponding to the extreme ends of the Haemophilus influenzae type b (Hib) hifA and hifD genes and Southern blotting, a hifA-like gene (named ghfA) and a hifD-like gene (named ghfD) were identified in 6 of the 19 strains. Five of these six strains were from the genital tracts of adults, and one was from a neonate. For each gene, the nucleotide sequence was identical for the six strains. A hifE-like gene (named ghfE) was amplified from only one of the 19 genital strains of Haemophilus, but the ghfE probe gave a signal in Southern hybridization with the five other strains positive for ghfA and ghfD. Therefore, these strains may carry a ghfE-like gene. The Hib fimbrial gene cluster is located between the purE and pepN genes as previously described. For the 13 genital Haemophilus strains that lack fimbrial genes, this region corresponds to a noncoding sequence. Another major fimbrial gene designated the fimbrin gene was previously identified in a nontypeable H. influenzae strain. A fimbrin-like gene was identified for all of our 19 genital strains. This gene is similar to the ompP5 gene of many Haemophilus strains. Therefore, other, unidentified genes may explain the piliation observed in electron microscopy on genital Haemophilus strains which do not possess LKP-like fimbrial genes. Fimbrial genes were significantly associated with strains isolated from the genital tract. They may confer on the strain the ability to survive in the genital tract. PMID:9864189

  8. Evolving epidemiology of invasive Haemophilus infections in the post-vaccination era: results from a long-term population-based study.

    PubMed

    Berndsen, M R; Erlendsdóttir, H; Gottfredsson, M

    2012-09-01

    Historically, Haemophilus influenzae (Hi) serotype b (Hib) caused most invasive Haemophilus infections worldwide, mainly in children. In 1989 routine childhood vaccination against Hib was initiated in Iceland. We conducted a population-based study of all patients in the country with Haemophilus spp. isolated from sterile sites (n = 202), from 1983 to 2008. Epidemiology, clinical characteristics of the infections and serotypes of the isolates were compared during the pre-vaccination (1983-1989) and post-vaccination era (1990-2008). Following the vaccination, the overall incidence of Hib decreased from 6.4 to 0.3/100,000 per year (p <0.05) whereas the incidence did not change significantly for infections caused by Haemophilus sensu lato not serotype b, hereafter referred to as non-type b Hi (0.9 vs 1.2, respectively). The most frequent diagnosis prior to 1990 was meningitis caused by Hib, which was subsequently replaced by pneumonia and bacteraemia caused by non-type b Hi. Most commonly, non-type b Hi were non-typeable (NTHi; 40/59), followed by Hi serotype f (14/59) and Hi serotype a (3/59). Pregnancy was associated with a markedly increased susceptibility to invasive Haemophilus infections (RR 25.7; 95% CI 8.0-95.9, p <0.0001) compared with non-pregnant women. The case fatality rate for Hib was 2.4% but 14% for non-type b Hi, highest at the extremes of age. Hib vaccination gives young children excellent protection and decreases incidence in the elderly due to herd effect in the community. Replacement with other species or serotypes has not been noted. Pregnant women are an overlooked risk group. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

  9. Postreplication Repair of Ultraviolet Damage in Haemophilus influenzae

    PubMed Central

    Leclerc, J. Eugene; Setlow, Jane K.

    1972-01-01

    The deoxyribonucleic acid (DNA) synthesized following ultraviolet (UV) irradiation of wild-type (Rd) and recombination-defective strains of Haemophilus influenzae has been analyzed by alkaline sucrose gradient sedimentation. Strain Rd and a UV-resistant, recombination-defective strain Rd(DB117) rec− are able to carry out postreplication repair, i.e., close the single-strand gaps in the newly synthesized DNA; in the UV-sensitive, recombination-defective strain DB117, the gaps remain open. The lack of postreplication repair in this strain may be the result of degradation of the newly synthesized DNA. PMID:4537422

  10. Comparative genomic and transcriptional analysis of virulent and non-virulent Haemophilus parasuis isolates

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis is a respiratory pathogen of swine and the etiological agent of Glässer's disease, a systemic infection resulting in polyserositis, meningitis, and arthritis. H. parasuis isolates can exhibit different virulence capabilities ranging from lethal systemic disease to subclinical ca...

  11. Beta- Lactam Antibiotics Stimulate Biofilm Formation in Non-Typeable Haemophilus influenzae by Up-Regulating Carbohydrate Metabolism

    PubMed Central

    Wu, Siva; Li, Xiaojin; Gunawardana, Manjula; Maguire, Kathleen; Guerrero-Given, Debbie; Schaudinn, Christoph; Wang, Charles; Baum, Marc M.; Webster, Paul

    2014-01-01

    Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10 µg/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended. PMID:25007395

  12. Epidemiology of Haemophilus ducreyi Infections.

    PubMed

    González-Beiras, Camila; Marks, Michael; Chen, Cheng Y; Roberts, Sally; Mitjà, Oriol

    2016-01-01

    The global epidemiology of Haemophilus ducreyi infections is poorly documented because of difficulties in confirming microbiological diagnoses. We evaluated published data on the proportion of genital and nongenital skin ulcers caused by H. ducreyi before and after introduction of syndromic management for genital ulcer disease (GUD). Before 2000, the proportion of GUD caused by H. ducreyi ranged from 0.0% to 69.0% (35 studies in 25 countries). After 2000, the proportion ranged from 0.0% to 15.0% (14 studies in 13 countries). In contrast, H. ducreyi has been recently identified as a causative agent of skin ulcers in children in the tropical regions; proportions ranged from 9.0% to 60.0% (6 studies in 4 countries). We conclude that, although there has been a sustained reduction in the proportion of GUD caused by H. ducreyi, this bacterium is increasingly recognized as a major cause of nongenital cutaneous ulcers.

  13. Draft genome sequences for ten isolates of the swine respiratory pathogen Haemophilus Parasuis

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis is a swine pathogen that causes pneumonia and Glässer’s disease, a systemic syndrome of polyserositis, arthritis, and meningitis. We report here the draft genomes of ten geographically diverse isolates collectively representing the full virulence spectrum of H. parasuis. These...

  14. The evidence for non-typeable Haemophilus influenzae as a causative agent of childhood pneumonia.

    PubMed

    Slack, Mary P E

    2017-01-01

    Haemophilus influenzae type b (Hib) was a major cause of bacterial pneumonia in children prior to the introduction of Hib-conjugate vaccines. The widespread use of Hib-conjugate vaccines has resulted in a significant decline in the number of cases of invasive Hib disease, including bacteraemic pneumonia, in areas where the vaccine has been implemented. In many countries, non-typeable H. influenzae (NTHI) is now the most common cause of invasive haemophilus infection in all ages. NTHI are a recognized cause of bacteraemic and non-bacteraemic pneumonia in children and in adults. Less than 10% of cases of pediatric pneumonia are bacteraemic, and children generally do not expectorate lower respiratory tract secretions, so determining the microbial cause of a non-bacteraemic pneumonia is challenging. In this commentary the evidence that NTHI is a cause of pneumonia in children is briefly reviewed.

  15. Detection of Cryptic Genospecies Misidentified as Haemophilus influenzae in Routine Clinical Samples by Assessment of Marker Genes fucK, hap, and sodC▿

    PubMed Central

    Nørskov-Lauritsen, Niels

    2009-01-01

    Clinical isolates of Haemophilus influenzae were assessed for the presence of fucK, hap, and sodC by hybridization with gene-specific probes, and isolates diverging from the expected H. influenzae genotype were characterized by phenotype and 16S rRNA gene sequencing. Two of 480 isolates were finally classified as variant strains (“nonhemolytic Haemophilus haemolyticus”). PMID:19535530

  16. Detection of cryptic genospecies misidentified as Haemophilus influenzae in routine clinical samples by assessment of marker genes fucK, hap, and sodC.

    PubMed

    Nørskov-Lauritsen, Niels

    2009-08-01

    Clinical isolates of Haemophilus influenzae were assessed for the presence of fucK, hap, and sodC by hybridization with gene-specific probes, and isolates diverging from the expected H. influenzae genotype were characterized by phenotype and 16S rRNA gene sequencing. Two of 480 isolates were finally classified as variant strains ("nonhemolytic Haemophilus haemolyticus").

  17. Virtual screening of phytochemicals to novel targets in Haemophilus ducreyi towards the treatment of Chancroid.

    PubMed

    Tripathi, Pranav; Chaudhary, Ritu; Singh, Ajeet

    2014-01-01

    Conventionally, drugs are discovered by testing chemically synthesized compounds against a battery of in vivo biological screens. Information technology and Omic science enabled us for high throughput screening of compound libraries against biological targets and hits are then tested for efficacy in cells or animals. Chancroid, caused by Haemophilus ducreyi is a public health problem and has been recognized as a cofactor for Human Immunodeficiency Virus (HIV) transmission. It facilitates HIV transmission by providing an accessible portal entry, promoting viral shedding, and recruiting macrophages as well as CD4 cells to the skin. So, there is a requirement to develop an efficient drug to combat Chancroid that can also diminish HIV infection. In-silico screening of potential inhibitors against the target may facilitate in detection of the novel lead compounds for developing an effective chemo preventive strategy against Haemophilus ducreyi. The present study has investigated the effects of approximately 1100 natural compounds that inhibit three vital enzymes viz. Phosphoenolpyruvate phosphotransferase, Acetyl-coenzyme A carboxylase and Fructose 1, 6-bisphosphatase of Haemophilus ducreyi in reference to a commercial drug Rifabutin. Results reveal that the lead compound uses less energy to bind to target. The lead compound parillin has also been predicted as less immunogenic in comparison to Rifabutin. Further, better molecular dynamics, pharmacokinetics, pharmacodynamics and ADME-T properties establish it as an efficient chancroid preventer.

  18. Comparative studies of the genome, virulence, and protection of 10 Haemophilus parasuis strains

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis is the cause of Glässer’s disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. An enormous difference exists in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to asympto...

  19. On the evolution of the sexually transmitted bacteria Haemophilus ducreyi and Klebsiella granulomatis.

    PubMed

    Lagergård, Teresa; Bölin, Ingrid; Lindholm, Leif

    2011-08-01

    Haemophilus ducreyi and Klebsiella (Calymmatobacterium) granulomatis are sexually transmitted bacteria that cause characteristic, persisting ulceration on external genitals called chancroid and granuloma inguinale, respectively. Those ulcers are endemic in developing countries or exist, as does granuloma inguinale, only in some geographic "hot spots."H. ducreyi is placed in the genus Haemophilus (family Pasteurellacae); however, this phylogenetic position is not obvious. The multiple ways in which the bacterium may be adapted to its econiche through specialized nutrient acquisitions; defenses against the immune system; and virulence factors that increase attachment, fitness, and persistence within genital tissue are discussed below. The analysis of K. granulomatis phylogeny demonstrated a high degree of identity with other Klebsiella species, and the name K. granulomatis comb. nov. was proposed. Because of the difficulty in growing this bacterium on artificial media, its characteristics have not been sufficiently defined. More studies are needed to understand bacterial genetics related to the pathogenesis and evolution of K. granulomatis. © 2011 New York Academy of Sciences.

  20. Phylogeny of 54 representative strains of species in the family Pasteurellaceae as determined by comparison of 16S rRNA sequences.

    PubMed Central

    Dewhirst, F E; Paster, B J; Olsen, I; Fraser, G J

    1992-01-01

    Virtually complete 16S rRNA sequences were determined for 54 representative strains of species in the family Pasteurellaceae. Of these strains, 15 were Pasteurella, 16 were Actinobacillus, and 23 were Haemophilus. A phylogenetic tree was constructed based on sequence similarity, using the Neighbor-Joining method. Fifty-three of the strains fell within four large clusters. The first cluster included the type strains of Haemophilus influenzae, H. aegyptius, H. aphrophilus, H. haemolyticus, H. paraphrophilus, H. segnis, and Actinobacillus actinomycetemcomitans. This cluster also contained A. actinomycetemcomitans FDC Y4, ATCC 29522, ATCC 29523, and ATCC 29524 and H. aphrophilus NCTC 7901. The second cluster included the type strains of A. seminis and Pasteurella aerogenes and H. somnus OVCG 43826. The third cluster was composed of the type strains of Pasteurella multocida, P. anatis, P. avium, P. canis, P. dagmatis, P. gallinarum, P. langaa, P. stomatis, P. volantium, H. haemoglobinophilus, H. parasuis, H. paracuniculus, H. paragallinarum, and A. capsulatus. This cluster also contained Pasteurella species A CCUG 18782, Pasteurella species B CCUG 19974, Haemophilus taxon C CAPM 5111, H. parasuis type 5 Nagasaki, P. volantium (H. parainfluenzae) NCTC 4101, and P. trehalosi NCTC 10624. The fourth cluster included the type strains of Actinobacillus lignieresii, A. equuli, A. pleuropneumoniae, A. suis, A. ureae, H. parahaemolyticus, H. parainfluenzae, H. paraphrohaemolyticus, H. ducreyi, and P. haemolytica. This cluster also contained Actinobacillus species strain CCUG 19799 (Bisgaard taxon 11), A. suis ATCC 15557, H. ducreyi ATCC 27722 and HD 35000, Haemophilus minor group strain 202, and H. parainfluenzae ATCC 29242. The type strain of P. pneumotropica branched alone to form a fifth group. The branching of the Pasteurellaceae family tree was quite complex. The four major clusters contained multiple subclusters. The clusters contained both rapidly and slowly evolving

  1. A humoral immune response confers protection against Haemophilus ducreyi infection.

    PubMed

    Cole, Leah E; Toffer, Kristen L; Fulcher, Robert A; San Mateo, Lani R; Orndorff, Paul E; Kawula, Thomas H

    2003-12-01

    Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. Neither naturally occurring chancroid nor experimental infection with H. ducreyi results in protective immunity. Likewise, a single inoculation of H. ducreyi does not protect pigs against subsequent infection. Accordingly, we used the swine model of chancroid infection to examine the impact of multiple inoculations on a host's immune response. After three successive inoculations with H. ducreyi, pigs developed a modestly protective immune response evidenced by the decreased recovery of viable bacteria from lesions. All lesions biopsied 2 days after the first and second inoculations contained viable H. ducreyi cells, yet only 55% of the lesions biopsied 2 days after the third inoculation did. Nearly 90% of the lesions biopsied 7 days after the first inoculation contained viable H. ducreyi cells, but this percentage dropped to only 16% after the third inoculation. Between the first and third inoculations, the average recovery of CFU from lesions decreased approximately 100-fold. The reduced recovery of bacteria corresponded directly with a fivefold increase in H. ducreyi-specific antibody titers and the emergence of bactericidal activity. These immune sera were protective when administered to naïve pigs prior to challenge with H. ducreyi. These data suggest that pigs mount an effective humoral immune response to H. ducreyi after multiple exposures to the organism.

  2. Haemophilus influenzae meningitis 5 years after introduction of the Haemophilus influenzae type b conjugate vaccine in Brazil.

    PubMed

    Ribeiro, Guilherme S; Lima, Josilene B T; Reis, Joice N; Gouveia, Edilane L; Cordeiro, Soraia M; Lobo, Tatiana S; Pinheiro, Ricardo M; Ribeiro, Cássio T; Neves, Alan B; Salgado, Kátia; Silva, Hagamenon R; Reis, Mitermayer G; Ko, Albert I

    2007-05-30

    The long-term impact of Haemophilus influenzae type b (Hib) conjugate vaccine, introduced throughout Latin America in the late 1990s, has not been evaluated. Active surveillance for H. influenzae meningitis was performed from August 9, 1996 to August 8, 2004 in Metropolitan Salvador, Brazil. Five years after the introduction of Hib conjugate vaccine, Hib meningitis incidence decreased from 2.39 to 0.06 cases per 100,000 population (98%) overall, and from 60.9 to 3.1 cases per 100,000 population (95%) in children <1 year of age. A transient serotype replacement phenomenon was observed associated with a small increase of meningitis due to two H. influenzae type a clonal groups. These findings indicate that Hib immunization campaign has led to the virtual elimination of Hib disease in this region.

  3. Successful protection against heterologous strains of Haemophilus parasuis: the quest for cross protective factors

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis (H. parasuis) infection in swine causes polyserositis, arthritis, and meningitis. Within the 15 serovars, there is a combination of virulent and nonvirulent strains, which has left the pathogenicity and subsequent protection from H. parasuis disease unclear. Here we used bacteri...

  4. The quest for cross protective factors of Haemophilus parasuis using 2-D gel electrophoresis

    USDA-ARS?s Scientific Manuscript database

    In swine, Haemophilus parasuis (H. parasuis) infection causes polyserositis, arthritis, and meningitis. A range of virulent to nonvirulent strains exists between and within the 15 serovars. Because of this, the pathogenicity and subsequent protection from H. parasuis disease has yet to be elucidated...

  5. Haemophilus Responses to Nutritional Immunity: Epigenetic and Morphological Contribution to Biofilm Architecture, Invasion, Persistence and Disease Severity

    PubMed Central

    Szelestey, Blake R.; Heimlich, Derek R.; Raffel, Forrest K.; Justice, Sheryl S.; Mason, Kevin M.

    2013-01-01

    In an effort to suppress microbial outgrowth, the host sequesters essential nutrients in a process termed nutritional immunity. However, inflammatory responses to bacterial insult can restore nutritional resources. Given that nutrient availability modulates virulence factor production and biofilm formation by other bacterial species, we hypothesized that fluctuations in heme-iron availability, particularly at privileged sites, would similarly influence Haemophilus biofilm formation and pathogenesis. Thus, we cultured Haemophilus through sequential heme-iron deplete and heme-iron replete media to determine the effect of transient depletion of internal stores of heme-iron on multiple pathogenic phenotypes. We observed that prior heme-iron restriction potentiates biofilm changes for at least 72 hours that include increased peak height and architectural complexity as compared to biofilms initiated from heme-iron replete bacteria, suggesting a mechanism for epigenetic responses that participate in the changes observed. Additionally, in a co-infection model for human otitis media, heme-iron restricted Haemophilus, although accounting for only 10% of the inoculum (90% heme-iron replete), represented up to 99% of the organisms recovered at 4 days. These data indicate that fluctuations in heme-iron availability promote a survival advantage during disease. Filamentation mediated by a SulA-related ortholog was required for optimal biofilm peak height and persistence during experimental otitis media. Moreover, severity of disease in response to heme-iron restricted Haemophilus was reduced as evidenced by lack of mucosal destruction, decreased erythema, hemorrhagic foci and vasodilatation. Transient restriction of heme-iron also promoted productive invasion events leading to the development of intracellular bacterial communities. Taken together, these data suggest that nutritional immunity, may, in fact, foster long-term phenotypic changes that better equip bacteria for

  6. Pediatric invasive disease due to Haemophilus influenzae serogroup A in Riyadh, Saudi Arabia: case series.

    PubMed

    Roaa, Zailaie; Abdulsalam, Alawfi; Shahid, Ghazi; Kamaldeen, Baba; Tariq, Al Fawaz

    2016-05-31

    We describe the first two cases of invasive disease caused by Haemophilus influenzae serotype A in Saudi Arabia. This is the first known reported invasive Haemophilus influenzae serotype A from Saudi Arabia. A ten-month-old and three-month-old male not known to have any past history of any medical illness and who had received H. influenzae type b (Hib) vaccine presented to our hospital mainly with fever of few days' duration. A provisional diagnosis of meningitis with sepsis was made and laboratory tests were requested. The chest radiograph was normal. The laboratory results revealed leukocytosis, but leukopenia was noticed in the younger infant. Blood culture and cerebrospinal fluid specimens yielded a pure culture of Haemophilus influenzae and serotyping showed the isolates to be serogroup A. Both patients were started on vancomycin and third-generation cephalosporin. On receiving the blood culture result, vancomycin was stopped. Fever subsided after 48 hours, while in the second case, it continued for 12 days from the admission date. The repeat blood cultures were negative. Antibiotic therapy was given for 10 days for the first case with an unremarkable hospital course, while the second case was complicated by seizure and received a longer duration of antibiotics. Both infants were discharged home in good condition. Invasive non-typeable H. influenzae strains are emerging and there is a need for surveillance of this disease. This has implications in future vaccine development.

  7. Virulence factors and mechanisms of antibiotic resistance of haemophilus influenzae.

    PubMed

    Kostyanev, Tomislav S; Sechanova, Lena P

    2012-01-01

    Haemophilus influenzae is a small gram-negative coccobacillus known as one of the major causes of meningitis, otitis media, sinusitis and epiglottitis, especially in childhood, as well as infections of the lower respiratory tract, eye infections and bacteremia. It has several virulence factors that play a crucial role in patient inflammatory response. Its capsule, the adhesion proteins, pili, the outer membrane proteins, the IgA1 protease and, last but not least, the lipooligosaccharide, increase the virulence of H. influenzae by participating actively in the host invasion the host by the microrganism. Some of these factors are used in vaccine preparations. In the post-vaccine era, an increase has been noticed in many European countries of invasive infections caused by non-encapsulated strains of H. influenzae which have a number of virulence factors, some of which are subject of serious research aiming at creating new vaccines. Numerous mechanisms of antibiotic resistance in H. influenzae are known which can compromise the empirical treatment of infections caused by this microorganism. The increasing incidence of resistance to aminopenicillins, induced not only by enzyme mechanisms but also by a change of their target is turning into a significant problem. Resistance to other antibiotics such as macrolides, tetracyclines, chloramphenicol, trimethoprim/sulfamethoxazole, and fluoroquinolones, commonly used to treat Haemophilus infections has also been described.

  8. Complicated meningitis caused by a rare serotype of Haemophilus influenzae in Portugal.

    PubMed

    Calado, Rita; Betencourt, Célia; Gonçalves, Helder; Cristino, Nuno; Calhau, Paulo; Lavado, Paula Bajanca

    2011-01-01

    We report a case of meningitis due to Haemophilus influenzae serotype d strain in an infant. As far as we know, this is the first report of a serotype d strain, responsible for childhood invasive disease in Europe, demonstrating an emerging of H. influenzae non-b serotype, in the post-vaccination era. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Analysis of major antigens of Haemophilus (Actinobacillus) pleuropneumoniae and related organisms.

    PubMed Central

    MacInnes, J I; Rosendal, S

    1987-01-01

    Outer membrane protein (OMP)-enriched extracts and whole-cell protein preparations of Haemophilus (Actinobacillus) pleuropneumoniae and related organisms were examined by polyacrylamide gel electrophoresis and immunoblotting. Both the OMP-enriched and whole-cell protein profiles of Actinobacillus suis, A. pleuropneumoniae (NAD-independent biovar), A. lignieresii, and Pasteurella haemolytica were very similar to those of H. pleuropneumoniae serotypes 1 to 8. Antisera prepared against H. pleuropneumoniae typically recognized three major OMP antigens with approximate molecular weights of 17,000 (17K), 32K, and 42K in immunoblots of H. pleuropneumoniae serotypes 1 to 8, Actinobacillus spp., and P. haemolytica. Antisera prepared against Actinobacillus spp. and Haemophilus sp. "minor group" also recognized these 17K, 32K, and 42K antigens. Using absorbed sera, we demonstrated that the 17K antigen had an epitope (or epitopes) common to all the gram-negative organisms examined, including Escherichia coli. The 32K and 42K antigens had epitopes common to members of the family Pasteurellaceae but, in the case of the 32K antigen, also contained unique epitopes. These results provide a basis for understanding the lack of specificity of serodiagnostic tests for H. pleuropneumoniae infection and provide another line of evidence for the association of H. pleuropneumoniae with the genus Actinobacillus. Images PMID:3298061

  10. Vaccine development for protection against systemic infections with Streptococcus suis and Haemophilus parasuis in swine

    USDA-ARS?s Scientific Manuscript database

    Both Streptococcus suis and Haemophilus parasuis are important invasive bacterial pathogens of swine, commonly causing meningitis, arthritis, polyserositis, and septicemia. Due to the presence of many serotypes and high genotypic variability, efficacious vaccines are not readily available. We are us...

  11. Identification of novel Haemophilus parasuis serovar 5 vaccine candidates using an immunoproteomic approach.

    PubMed

    Li, Gang; Xie, Fang; Li, Jianjun; Liu, Jiao; Li, Dapeng; Zhang, Yanhe; Langford, Paul R; Li, Yanwen; Liu, Siguo; Wang, Chunlai

    2017-06-23

    Haemophilus parasuis is the aetiological agent of Glässer's disease, which is responsible for cases of fibrinous polyserositis, polyarthritis and meningitis. No vaccine is known that provides cross-protection against all serovars. The identification of novel immunoprotective antigens would undoubtedly contribute to the development of efficient subunit vaccines. In the present study, an immunoproteomic approach was used to analyze secreted proteins of H. parasuis and six proteins with high immunogenicity were identified. Five of them were successfully expressed, and their immunogenicity and protective efficacy were assessed in a mouse challenge model. All five proteins elicited strong humoral antibody and cellular immune responses in mice. They all effectively reduced the growth of H. parasuis in mouse organs and conferred different levels of protection (40-80%) against challenge. IgG subtype analysis revealed that the five proteins induce a bias toward a Th1-type immune response, and a significant increase was observed in the cytokine levels of IL-2, IFN-γ and Th2-specific IL-4 in the culture supernatants of splenocytes isolated from immunized mice. The results suggest that both Th1 and Th2 responses are involved in mediating protection. These data suggest that the five proteins could be potential subunit vaccine candidates for use to prevent H. parasuis infection. Haemophilus parasuis can cause huge financial loss in the swine industry worldwide. There are still no vaccines which can provide cross-protection against all serovars. To address this need, we applied an immunoproteomic approach involving 2-DE, MALDI-TOF/TOF MS and Western-blot to identify the secreted proteins which may be able to provide immunoprotection to this disease. We identified six immunogenic proteins, and the immunogenicity and protective efficacy were validated. This result provides a foundation for developing novel subunit vaccines against Haemophilus parasuis. Copyright © 2017

  12. Haemophilus influenzae type f meningitis in a previously healthy boy

    PubMed Central

    Ronit, Andreas; Berg, Ronan M G; Bruunsgaard, Helle; Plovsing, Ronni R

    2013-01-01

    Non-serotype b strains of Haemophilus influenzae are extremely rare causes of acute bacterial meningitis in immunocompetent individuals. We report a case of acute bacterial meningitis in a 14-year-old boy, who was previously healthy and had been immunised against H influenzae serotype b (Hib). The causative pathogen was identified as H influenzae serotype f (Hif), and was successfully treated with ceftriaxone. An immunological evaluation revealed transient low levels of immunoglobulins but no apparent immunodeficiency was found 2 years after the clinical insult. PMID:23645639

  13. Haemophilus influenzae type f meningitis in a previously healthy boy.

    PubMed

    Ronit, Andreas; Berg, Ronan M G; Bruunsgaard, Helle; Plovsing, Ronni R

    2013-05-02

    Non-serotype b strains of Haemophilus influenzae are extremely rare causes of acute bacterial meningitis in immunocompetent individuals. We report a case of acute bacterial meningitis in a 14-year-old boy, who was previously healthy and had been immunised against H influenzae serotype b (Hib). The causative pathogen was identified as H influenzae serotype f (Hif), and was successfully treated with ceftriaxone. An immunological evaluation revealed transient low levels of immunoglobulins but no apparent immunodeficiency was found 2 years after the clinical insult.

  14. Chancroid and Haemophilus ducreyi: an update.

    PubMed Central

    Trees, D L; Morse, S A

    1995-01-01

    Haemophilus ducreyi is a fastidious gram-negative bacillus that causes the sexually transmitted infection chancroid. Chancroid is a major genital ulcerative disease in Africa, Southeast Asia, the Caribbean, and Latin America and is of increasing concern in the United States. Genital ulcerative disease and chancroid in particular have been associated with facilitating the transmission of human immunodeficiency virus. The diagnosis of chancroid based on the clinical appearance of the genital lesion or on the isolation of H. ducreyi on selective medium is relatively insensitive. However, recent advances in nonculture diagnostic tests have enhanced our ability to diagnose chancroid. There has been renewed interest in understanding the pathogenesis of H. ducreyi. In vitro and in vivo models have been developed to help identify important virulence determinants. Through the use of biochemical and molecular techniques, macromolecular components that may be important in virulence have been identified. PMID:7553570

  15. Chancroid and Haemophilus ducreyi: an update.

    PubMed

    Trees, D L; Morse, S A

    1995-07-01

    Haemophilus ducreyi is a fastidious gram-negative bacillus that causes the sexually transmitted infection chancroid. Chancroid is a major genital ulcerative disease in Africa, Southeast Asia, the Caribbean, and Latin America and is of increasing concern in the United States. Genital ulcerative disease and chancroid in particular have been associated with facilitating the transmission of human immunodeficiency virus. The diagnosis of chancroid based on the clinical appearance of the genital lesion or on the isolation of H. ducreyi on selective medium is relatively insensitive. However, recent advances in nonculture diagnostic tests have enhanced our ability to diagnose chancroid. There has been renewed interest in understanding the pathogenesis of H. ducreyi. In vitro and in vivo models have been developed to help identify important virulence determinants. Through the use of biochemical and molecular techniques, macromolecular components that may be important in virulence have been identified.

  16. Clinical findings and management of patients with meningitis with an emphasis on Haemophilus influenzae meningitis in rural Tanzania.

    PubMed

    Storz, Corinna; Schutz, Cornelia; Tluway, Anthony; Matuja, William; Schmutzhard, Erich; Winkler, Andrea S

    2016-07-15

    The spectrum of meningitis pathogens differs depending on the age of patients and the geographic region, amongst other. Although meningitis vaccination programs have led to the reduction of incidence rates, an imbalance between low- and high-income countries still exists. In a hospital-based study in rural northern Tanzania, we consecutively recruited patients with confirmed meningitis and described their clinical and laboratory characteristics. A total of 136 patients with meningitis were included. Fever (85%), meningism (63%) and impairment of consciousness (33%) were the most frequent clinical symptoms/signs. Nearly 10% of all patients tested were positive for malaria. The majority of the patients with bacterial meningitis (39%), especially those under 5years of age, were confirmed to be infected with Haemophilus influenzae (26%), Streptococcus pneumoniae (19%) and Neisseria meningitidis (15%). Haemophilus influenzae represented the dominant causative organism in children under 2years of age. Our study emphasizes the importance of recognizing warning symptoms like fever, meningism and impairment of consciousness, implementing laboratory tests to determine responsible pathogens and evaluating differential diagnoses in patients with meningitis in sub-Saharan Africa. It also shows that Haemophilus influenza meningitis is still an important cause for meningitis in the young, most probabaly due to lack of appropriate vaccination coverage. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. The Association of Chronic Hepatitis C with Respiratory Microbiota Disturbance on the Basis of Decreased Haemophilus Spp. Colonization

    PubMed Central

    Kosikowska, Urszula; Biernasiuk, Anna; Korona-Głowniak, Izabela; Kiciak, Sławomir; Tomasiewicz, Krzysztof; Malm, Anna

    2016-01-01

    Background Haemophilus species are the most common microbiota in humans. The aim of this paper was to investigate Haemophilus spp., mainly H. parainfluenzae prevalence, in the upper respiratory tract of chronic hepatitis C (CHC-positive) patients with or without therapy using pegylated interferon alfa and ribavirin. Material/Methods We collected 462 samples from 54 healthy people and 100 CHC-positive patients at various stages: before (group A), during (group B), and after (group C) antiviral therapy. Identification of bacterial isolates including biotypes and antimicrobials susceptibility was accomplished by means of standard microbiological methods. Results In 70.4% of healthy people (control group) and in 27.0% of CHC-positive patients, the presence of haemophili, mainly H. parainfluenzae was observed, and those differences were statistically significant (p<0.0001). Statistically significant differences in Haemophilus spp. colonization were also observed among healthy people and CHC-positive patients from group A (p=0.0012) and from B or C groups (p<0.0001). Resistance to ampicillin in beta-lactamase-positive isolates and multidrug resistance (MDR) of H. parainfluenzae was detected mainly in group A. Conclusions The obtained data suggest that chronic hepatitis C, together with antiviral therapy, may influence the respiratory tract microbiota composition as found using haemophili, mainly H. parainfluenzae. PMID:26912163

  18. Difficult identification of Haemophilus influenzae, a typical cause of upper respiratory tract infections, in the microbiological diagnostic routine.

    PubMed

    Hinz, Rebecca; Zautner, Andreas Erich; Hagen, Ralf Matthias; Frickmann, Hagen

    2015-03-01

    Haemophilus influenzae is a key pathogen of upper respiratory tract infections. Its reliable discrimination from nonpathogenic Haemophilus spp. is necessary because merely colonizing bacteria are frequent at primarily unsterile sites. Due to close phylogenetic relationship, it is not easy to discriminate H. influenzae from the colonizer Haemophilus haemolyticus. The frequency of H. haemolyticus isolations depends on factors like sampling site, patient condition, and geographic region. Biochemical discrimination has been shown to be nonreliable. Multiplex PCR including marker genes like sodC, fucK, and hpd or sequencing of the 16S rRNA gene, the P6 gene, or multilocus-sequence-typing is more promising. For the diagnostic routine, such techniques are too expensive and laborious. If available, matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry is a routine-compatible option and should be used in the first line. However, the used database should contain well-defined reference spectra, and the spectral difference between H. influenzae and H. haemolyticus is small. Fluorescence in-situ hybridization is an option for less well-equipped laboratories, but the available protocol will not lead to conclusive results in all instances. It can be used as a second line approach. Occasional ambiguous results have to be resolved by alternative molecular methods like 16S rRNA gene sequencing.

  19. Structure and Function of the Haemophilus influenzae Autotransporters

    PubMed Central

    Spahich, Nicole A.; St. Geme, Joseph W.

    2011-01-01

    Autotransporters are a large class of proteins that are found in the outer membrane of Gram-negative bacteria and are almost universally implicated in virulence. These proteins consist of a C-terminal β-domain that is embedded in the outer membrane and an N-terminal domain that is exposed on the bacterial surface and is endowed with effector function. In this article, we review and compare the structural and functional characteristics of the Haemophilus influenzae IgA1 protease and Hap monomeric autotransporters and the H. influenzae Hia and Hsf trimeric autotransporters. All of these proteins play a role in colonization of the upper respiratory tract and in the pathogenesis of H. influenzae disease. PMID:22919571

  20. Changes in the prevalence and biofilm formation of Haemophilus influenzae and Haemophilus parainfluenzae from the respiratory microbiota of patients with sarcoidosis.

    PubMed

    Kosikowska, Urszula; Rybojad, Paweł; Stępień-Pyśniak, Dagmara; Żbikowska, Anna; Malm, Anna

    2016-08-26

    Healthy condition and chronic diseases may be associated with microbiota composition and its properties. The prevalence of respiratory haemophili with respect to their phenotypes including the ability to biofilm formation in patients with sarcoidosis was assayed. Nasopharynx and sputum specimens were taken in 31 patients with sarcoidosis (average age 42.6 ± 13), and nasopharynx specimens were taken in 37 healthy people (average age 44.6 ± 11.6). Haemophili were identified by API-NH microtest and by the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system. Biofilm was visualised by crystal violet staining and confocal scanning laser microscopy (CSLM). The statistical analysis was performed with Statgraphics Plus for Windows. In total, 30/31 patients with sarcoidosis and 31/37 healthy people were colonized by Haemophilus influenzae (6/30 vs. 1/31) and Haemophilus parainfluenzae (28/30 vs. 31/31) in the nasopharynx. The overall number of nasopharyngeal haemophili isolates was 59 in patients with sarcoidosis and 67 in healthy volunteers (H. influenzae 6/59 vs. 1/67, P = 0.05; H. parainfluenzae 47/59 vs. 65/67, P = 0.0032). Moreover, the decreased number of H. parainfluenzae biofilm-producing isolates was shown in nasopharyngeal samples in patients with sarcoidosis as compared to healthy people (19/31 vs. 57/65, P = 0.006), especially with respect to isolates classified as strong and very strong biofilm-producers (8/31 vs. 39/65, P = 0.002). The obtained data suggest that the qualitative and quantitative changes within the respiratory microbiota concerning the overall prevalence of H. influenzae together with the decreased number of H. parainfluenzae strains and the decreased rate of H. parainfluenzae biofilm-producing isolates as compared to healthy people may be associated with sarcoidosis.

  1. Haemophilus influenzae type B meningitis in a previously healthy child.

    PubMed

    Horowitz, Ira N; Baorto, Elizabeth; Davis, Jennifer; Barisciano, Lisa

    2010-10-01

    Vaccines have proven successful in virtually eradicating certain infectious diseases that typically attack the pediatric population. Since 1988, when the conjugate vaccine was introduced, the incidence of invasive Haemophilus influenzae type B disease was reduced dramatically. However, immunization rates have decreased in certain parts of the country because of a combination of vaccine shortage and widespread parental perception that vaccines are harmful. We present the case of a previous healthy child, who ultimately succumbed to H. influenzae type B meningitis where multiple factors were likely responsible for his acquisition of the disease.

  2. 63 FR 47026 - Proposed Vaccine Information Materials for Hepatitis B, Haemophilus influenzae type b (Hib...

    Federal Register 2010, 2011, 2012, 2013, 2014

    1998-09-03

    ... United States. Meningitis is an infection of the brain and spinal cord coverings which can lead to..., meningitis (infection of the brain and spinal cord covering), painful swelling of the testicles, and, rarely... Vaccine Information Materials for Hepatitis B, Haemophilus influenzae type b (Hib), Varicella (Chickenpox...

  3. Virulence and draft genome sequence overview of multiple strains of the swine pathogen Haemophilus parasuis

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis is the cause of Glässer’s disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. Characterization of this animal disease is complicated by the enormous differences in the severity of disease caused by H. parasuis str...

  4. Difficult identification of Haemophilus influenzae, a typical cause of upper respiratory tract infections, in the microbiological diagnostic routine

    PubMed Central

    Hinz, Rebecca; Zautner, Andreas Erich; Hagen, Ralf Matthias

    2015-01-01

    Haemophilus influenzae is a key pathogen of upper respiratory tract infections. Its reliable discrimination from nonpathogenic Haemophilus spp. is necessary because merely colonizing bacteria are frequent at primarily unsterile sites. Due to close phylogenetic relationship, it is not easy to discriminate H. influenzae from the colonizer Haemophilus haemolyticus. The frequency of H. haemolyticus isolations depends on factors like sampling site, patient condition, and geographic region. Biochemical discrimination has been shown to be nonreliable. Multiplex PCR including marker genes like sodC, fucK, and hpd or sequencing of the 16S rRNA gene, the P6 gene, or multilocus-sequence-typing is more promising. For the diagnostic routine, such techniques are too expensive and laborious. If available, matrix-assisted laser-desorption–ionization time-of-flight mass spectrometry is a routine-compatible option and should be used in the first line. However, the used database should contain well-defined reference spectra, and the spectral difference between H. influenzae and H. haemolyticus is small. Fluorescence in-situ hybridization is an option for less well-equipped laboratories, but the available protocol will not lead to conclusive results in all instances. It can be used as a second line approach. Occasional ambiguous results have to be resolved by alternative molecular methods like 16S rRNA gene sequencing. PMID:25883794

  5. Molecular Surveillance of True Nontypeable Haemophilus influenzae: An Evaluation of PCR Screening Assays

    PubMed Central

    Binks, Michael J.; Temple, Beth; Kirkham, Lea-Ann; Wiertsema, Selma P.; Dunne, Eileen M.; Richmond, Peter C.; Marsh, Robyn L.; Leach, Amanda J.; Smith-Vaughan, Heidi C.

    2012-01-01

    Background Unambiguous identification of nontypeable Haemophilus influenzae (NTHi) is not possible by conventional microbiology. Molecular characterisation of phenotypically defined NTHi isolates suggests that up to 40% are Haemophilus haemolyticus (Hh); however, the genetic similarity of NTHi and Hh limits the power of simple molecular techniques such as PCR for species discrimination. Methodology/Principal Findings Here we assess the ability of previously published and novel PCR-based assays to identify true NTHi. Sixty phenotypic NTHi isolates, classified by a dual 16S rRNA gene PCR algorithm as NTHi (n = 22), Hh (n = 27) or equivocal (n = 11), were further characterised by sequencing of the 16S rRNA and recA genes then interrogated by PCR-based assays targeting the omp P2, omp P6, lgtC, hpd, 16S rRNA, fucK and iga genes. The sequencing data and PCR results were used to define NTHi for this study. Two hpd real time PCR assays (hpd#1 and hpd#3) and the conventional iga PCR assay were equally efficient at differentiating study-defined NTHi from Hh, each with a receiver operator characteristic curve area of 0.90 [0.83; 0.98]. The hpd#1 and hpd#3 assays were completely specific against a panel of common respiratory bacteria, unlike the iga PCR, and the hpd#3 assay was able to detect below 10 copies per reaction. Conclusions/Significance Our data suggest an evolutionary continuum between NTHi and Hh and therefore no single gene target could completely differentiate NTHi from Hh. The hpd#3 real time PCR assay proved to be the superior method for discrimination of NTHi from closely related Haemophilus species with the added potential for quantification of H. influenzae directly from specimens. We suggest the hpd#3 assay would be suitable for routine NTHi surveillance and to assess the impact of antibiotics and vaccines, on H. influenzae carriage rates, carriage density, and disease. PMID:22470516

  6. Molecular surveillance of true nontypeable Haemophilus influenzae: an evaluation of PCR screening assays.

    PubMed

    Binks, Michael J; Temple, Beth; Kirkham, Lea-Ann; Wiertsema, Selma P; Dunne, Eileen M; Richmond, Peter C; Marsh, Robyn L; Leach, Amanda J; Smith-Vaughan, Heidi C

    2012-01-01

    Unambiguous identification of nontypeable Haemophilus influenzae (NTHi) is not possible by conventional microbiology. Molecular characterisation of phenotypically defined NTHi isolates suggests that up to 40% are Haemophilus haemolyticus (Hh); however, the genetic similarity of NTHi and Hh limits the power of simple molecular techniques such as PCR for species discrimination. Here we assess the ability of previously published and novel PCR-based assays to identify true NTHi. Sixty phenotypic NTHi isolates, classified by a dual 16S rRNA gene PCR algorithm as NTHi (n = 22), Hh (n = 27) or equivocal (n = 11), were further characterised by sequencing of the 16S rRNA and recA genes then interrogated by PCR-based assays targeting the omp P2, omp P6, lgtC, hpd, 16S rRNA, fucK and iga genes. The sequencing data and PCR results were used to define NTHi for this study. Two hpd real time PCR assays (hpd#1 and hpd#3) and the conventional iga PCR assay were equally efficient at differentiating study-defined NTHi from Hh, each with a receiver operator characteristic curve area of 0.90 [0.83; 0.98]. The hpd#1 and hpd#3 assays were completely specific against a panel of common respiratory bacteria, unlike the iga PCR, and the hpd#3 assay was able to detect below 10 copies per reaction. Our data suggest an evolutionary continuum between NTHi and Hh and therefore no single gene target could completely differentiate NTHi from Hh. The hpd#3 real time PCR assay proved to be the superior method for discrimination of NTHi from closely related Haemophilus species with the added potential for quantification of H. influenzae directly from specimens. We suggest the hpd#3 assay would be suitable for routine NTHi surveillance and to assess the impact of antibiotics and vaccines, on H. influenzae carriage rates, carriage density, and disease.

  7. [Haemophilus influenzae b among bacterial meningitis in Bamako (2002-2004)].

    PubMed

    Diawara, A; Sangho, H; Sissoko, M; Bougoudogo, F; Doumbo, O

    2008-01-01

    In Mali little study exist on the meningitis with Haemophilus influenzae b (Hib). This weak data availability on Hib meningitis, didn't permit to introduce the immunization against this pathology in the Expanded Program Immunization (EPI) of Mali. The present survey aims to improve the availability of the data on Hib meningitis and to advocate for the introduction of immunization against Hib in EPI in Mali. The survey consisted to the exploitation of spinal fluid examination data for the suspected cases of meningitis, sent by the different health centers to National Institute for Public Health Research (INRSP) on the period going from October 1st, 2002 to September 30, 2004. According to the survey, on 230 cases of meningitis whose germs have been identified to the latex and the culture, Hib occupies the 3rd place with 21.3% among the bacterial meningitises. In Bamako Hib occupies the 2nd place (27.4%) according to the source. The persons less than 1 year (59.6%) were the more affected (p < 0.001) and the diseases distribution has been observed during the dry seasons (51.0%) and rainy (49.0%) without meaningful impact of temperature and rainfall (p > 0.05) (p = 0.8249). The cases of Hib identified were more sensitive to ciprofloxacine (100%) and to ceftriaxone (100%). Taken into consideration the cost raised of quinolones and cephalosporines, and in reference to the high mortality and frequent complications known of Hib meningitis, the introduction of immunization against Haemophilus influenzae in the Expanded Program Immunization should contribute to a better control of this disease.

  8. Whole-genome random sequencing and assembly of Haemophilus influenzae Rd

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fleischmann, R.D.; Adams, M.D.; White, O.

    1995-07-28

    An approach for genome analysis based on sequencing and assembly of unselected pieces of DNA from the whole chromosome has been applied to obtain the complete nucleotide sequence (1,830,137 base pairs) of the genome from the bacterium Haemophilus influenzae Rd. This approach eliminates the need for initial mapping efforts and is therefore applicable to the vast array of microbial species for which genome maps are unavailable. The H. influenzae Rd genome sequence (Genome Sequence DataBase accession number L42023) represents the only complete genome sequence from a free-living organism. 46 refs., 4 figs., 4 tabs.

  9. Haemophilus parainfluenzae bacteremia associated with a pacemaker wire localized by gallium scan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rosenbaum, G.S.; Calubiran, O.; Cunha, B.A.

    1990-05-01

    A young woman with a history of sick sinus syndrome and placement of a permanent pacemaker 6 months before admission had fever and Haemophilus parainfluenzae bacteremia. A gallium scan localized the infection to the site of the pacemaker wire. Echocardiograms were negative for any vegetations. The patient responded to cefotaxime and trimethoprim-sulfamethoxazole therapy. We believe that this is the first case of H. parainfluenzae bacteremia associated with a pacemaker wire and localized by gallium scan.

  10. Etiology of acute otitis media and serotype distribution of Streptococcus pneumoniae and Haemophilus influenzae in Chilean children <5 years of age

    PubMed Central

    Rosenblut, Andres; Napolitano, Carla; Pereira, Angelica; Moreno, Camilo; Kolhe, Devayani; Lepetic, Alejandro; Ortega-Barria, Eduardo

    2017-01-01

    Abstract The impact of bacterial conjugate vaccines on acute otitis media (AOM) is affected by several factors including population characteristics, bacterial etiology and vaccine conjugation method, carrier, and coverage. This study estimated the baseline etiology, distribution, and antibiotic susceptibility of bacterial serotypes that causes AOM in children aged <5 years in a public setting in Santiago, Chile. Children aged ≥3 months and <5 years referred to the physician for treatment of AOM episodes (with an onset of symptoms <72 h) were enrolled between September 2009 and September 2010. Middle ear fluid (MEF) was collected by tympanocentesis or by otorrhea for identification and serotyping of bacteria. Antibacterial susceptibility was tested using E-test (etrack: 112671). Of 160 children (mean age 27.10 ± 15.83 months) with AOM episodes, 164 MEF samples (1 episode each from 156 children; 2 episodes each from 4 children) were collected. Nearly 30% of AOM episodes occurred in children aged 12 to 23 months. Streptococcus pneumoniae (41.7% [58/139]) and Haemophilus influenzae (40.3% [56/139]) were predominant among the cultures that showed bacterial growth (85% [139/164]). All Streptococcus pneumoniae positive episodes were serotyped, 19F (21%) and 14 (17%) were the predominant serotypes; all Haemophilus influenzae strains were nontypeable. Streptococcus pneumoniae were resistant to penicillin (5%) and erythromycin (33%); Haemophilus influenzae were resistant to ampicillin (14%) and cefuroxime and cefotaxime (2% each). AOM in Chilean children is predominantly caused by Streptococcus pneumoniae and nontypeable Haemophilus influenzae. Use of a broad spectrum vaccine against these pathogens might aid the reduction of AOM in Chile. PMID:28178138

  11. β-Lactam resistance among Haemophilus influenzae isolates in Poland.

    PubMed

    Kiedrowska, Marlena; Kuch, Alicja; Żabicka, Dorota; Waśko, Izabela; Ronkiewicz, Patrycja; Wasiak, Katarzyna; Bojarska, Katarzyna; Hryniewicz, Waleria; Skoczyńska, Anna

    2017-12-01

    Haemophilus influenzae is a human-specific Gram-negative coccobacillus responsible for a significant number of respiratory tract infections and severe invasive infections such as meningitis and sepsis. The purpose of this study was to characterise the mechanisms of β-lactam resistance among Polish H. influenzae isolates and to evaluate the resistance detection methods applied. This study was conducted on 117 Polish H. influenzae isolates collected in 2012. Minimum inhibitory concentrations were assessed by broth microdilution. All strains were evaluated using the disk diffusion method and the algorithm proposed by the Nordic Committee on Antimicrobial Susceptibility Testing (NordicAST). To detect changes in penicillin-binding protein 3 (PBP3), PCR screening was performed, followed by ftsI gene sequencing. Neither β-lactamase production nor PBP3 alterations were demonstrated in 76 isolates (65.0%). Susceptibility to ampicillin, amoxicillin, amoxicillin/clavulanic acid, cefuroxime (intravenous) and ceftriaxone was observed in 70.9%, 78.6%, 98.3%, 82.9% and 100% of the isolates, respectively. β-Lactamase production characterised 21 isolates (17.9%). Screening PCR identified 20 isolates (17.1%) with PBP3 alterations, and according to subsequent ftsI sequencing all these strains were finally recognised as gBLNAR (genetically β-lactamase-negative, ampicillin-resistant), among which 65.0% were ampicillin-resistant. According to molecular classification of PBP3 alterations, 95.0% of gBLNAR belonged to group II, representing four subgroups IIa-IId. Haemophilus influenzae resistance to antibiotics requires continuous attention, effective detection methods and a rational policy of antibiotic usage. The algorithm proposed by NordicAST can be applied in routine laboratory work, whereas sequencing of the ftsI gene may be useful in molecular epidemiology studies. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All

  12. Serological cross-reactivity between a porcine Actinobacillus strain and Haemophilus pleuropneumoniae.

    PubMed Central

    Rosendal, S; Mittal, K R

    1985-01-01

    During serological screening of a closed SPF-herd free of pleuropneumonia, more than half of the pigs were positive for complement-fixing antibodies to Haemophilus pleuropneumoniae. Actinobacillus bacteria closely related to A. suis were isolated from tonsillar tissue of 14 out of 20 slaughtered pigs submitted for pathological and bacteriological evaluation. None of the pigs had evidence of respiratory disease. Two pigs inoculated endobronchially with a selected Actinobacillus strain developed mild focal pneumonia and complement-fixing antibodies cross-reacting with H. pleuropneumoniae. Five pigs exposed and vaccinated with the Actinobacillus strain and five pigs spontaneously infected with the strain also developed complement-fixing antibodies against H. pleuropneumoniae and appeared to be less susceptible to experimental Haemophilus pleuropneumonia than pigs not exposed to the Actinobacillus infection. The agglutination test applied on serum treated with 2-mercaptoethanol detected antibodies against H. pleuropneumoniae serotype 5 but not against serotype 1 in pigs exposed to the Actinobacillus strain. Antibodies reactive with the Actinobacillus strain were also found in pigs hyperimmunized against H. pleuropneumoniae serotypes 1-5 in 2-mercaptoethanol tube agglutination test and rabbits hyperimmunized against serotypes 1,2 and 7, and strain 73567 in the immunodiffusion test. Conversely rabbits immunized against the Actinobacillus strain had antibodies against H. pleuropneumoniae serotypes 1, 3, 4, 5 and 6. It is concluded that pigs infected with Actinobacillus organisms may become false positive reactors against H. pleuropneumoniae. PMID:3926287

  13. Nontypeable Haemophilus influenzae biofilms: role in chronic airway infections.

    PubMed

    Swords, W Edward

    2012-01-01

    Like many pathogens inhabiting mucosal surfaces, nontypeable Haemophilus influenzae (NTHi) forms multicellular biofilm communities both in vitro and in various infection models. In the past 15 years much has been learned about determinants of biofilm formation by this organism and potential roles in bacterial virulence, especially in the context of chronic and recurrent infections. However, this concept has not been without some degree of controversy, and in the past some have expressed doubts about the relevance of NTHi biofilms to disease. In this review, I will summarize the present information on the composition and potential role(s) of NTHi biofilms in different clinical contexts, as well as highlight potential areas for future work.

  14. Nontypeable Haemophilus influenzae biofilms: role in chronic airway infections

    PubMed Central

    Swords, W. Edward

    2012-01-01

    Like many pathogens inhabiting mucosal surfaces, nontypeable Haemophilus influenzae (NTHi) forms multicellular biofilm communities both in vitro and in various infection models. In the past 15 years much has been learned about determinants of biofilm formation by this organism and potential roles in bacterial virulence, especially in the context of chronic and recurrent infections. However, this concept has not been without some degree of controversy, and in the past some have expressed doubts about the relevance of NTHi biofilms to disease. In this review, I will summarize the present information on the composition and potential role(s) of NTHi biofilms in different clinical contexts, as well as highlight potential areas for future work. PMID:22919686

  15. Diversity of the P2 protein among nontypeable Haemophilus influenzae isolates.

    PubMed Central

    Bell, J; Grass, S; Jeanteur, D; Munson, R S

    1994-01-01

    The genes for outer membrane protein P2 of four nontypeable Haemophilus influenzae strains were cloned and sequenced. The derived amino acid sequences were compared with the outer membrane protein P2 sequence from H. influenzae type b MinnA and the sequences of P2 from three additional nontypeable H. influenzae strains. The sequences were 76 to 94% identical. The sequences had regions with considerable variability separated by regions which were highly conserved. The variable regions mapped to putative surface-exposed loops of the protein. PMID:8188390

  16. Haemophilus influenzae serotype e meningitis in an adult.

    PubMed

    Ulu-Kilic, Ayşegül; Kiliç, Ayşegül Ulu; Altay, Fatma Aybala; Gürbüz, Yunus; Otgun, Selin Nar; Sencan, Irfan

    2010-05-01

    The incidence of Haemophilus influenzae type b (Hib) invasive disease has declined significantly in countries with routine infant Hib immunization. Accordingly, infections caused by other H. influenzae serotypes or by encapsulated H. influenzae strains are of growing interest. H. influenzae serotype e (Hie) is a rare cause of infection. Invasive Hie infections reported in adults are generally in individuals who had previous underlying conditions, in contrast to infections in childhood. We present the first report of Hie meningitis in Turkey. It is of interest that meningitis due to this organism occured as a complication of transsphenoidal hypophysectomy, which to our knowledge has never been documented. Further identification of H. influenzae strains isolated from patients with invasive disease, especially those with predisposing factors and/or who have been vaccinated, is essential.

  17. Complete Deletion of the Fucose Operon in Haemophilus influenzae Is Associated with a Cluster in Multilocus Sequence Analysis-Based Phylogenetic Group II Related to Haemophilus haemolyticus: Implications for Identification and Typing

    PubMed Central

    de Gier, Camilla; Kirkham, Lea-Ann S.

    2015-01-01

    Nonhemolytic variants of Haemophilus haemolyticus are difficult to differentiate from Haemophilus influenzae despite a wide difference in pathogenic potential. A previous investigation characterized a challenging set of 60 clinical strains using multiple PCRs for marker genes and described strains that could not be unequivocally identified as either species. We have analyzed the same set of strains by multilocus sequence analysis (MLSA) and near-full-length 16S rRNA gene sequencing. MLSA unambiguously allocated all study strains to either of the two species, while identification by 16S rRNA sequence was inconclusive for three strains. Notably, the two methods yielded conflicting identifications for two strains. Most of the “fuzzy species” strains were identified as H. influenzae that had undergone complete deletion of the fucose operon. Such strains, which are untypeable by the H. influenzae multilocus sequence type (MLST) scheme, have sporadically been reported and predominantly belong to a single branch of H. influenzae MLSA phylogenetic group II. We also found evidence of interspecies recombination between H. influenzae and H. haemolyticus within the 16S rRNA genes. Establishing an accurate method for rapid and inexpensive identification of H. influenzae is important for disease surveillance and treatment. PMID:26378279

  18. Iron acquisition by Haemophilus influenzae.

    PubMed Central

    Pidcock, K A; Wooten, J A; Daley, B A; Stull, T L

    1988-01-01

    The mechanisms for acquisition of iron by Haemophilus influenzae and their role in pathogenesis are not known. Heme and nonheme sources of iron were evaluated for their effect on growth of type b and nontypable strains of H. influenzae in an iron-restricted, defined medium. All 13 strains acquired iron from heme, hemoglobin, hemoglobin-haptoglobin, and heme-hemopexin. Among nonheme sources of protein-bound iron, growth of H. influenzae was enhanced by partially saturated human transferrin but not by lactoferrin or ferritin. Purified ferrienterochelin and ferridesferrioxamine failed to provide iron to H. influenzae, and the supernatants of H. influenzae E1a grown in iron-restricted medium failed to enhance iron-restricted growth of siderophore-dependent strains of Escherichia coli, Salmonella typhimurium, and Arthrobacter terregens. Marked alterations in the profile of outer membrane proteins of H. influenzae were observed when the level of free iron was varied between 1 microM and 1 mM. Catechols were not detected in the supernatants of strain E1a; however, iron-related hydroxamate production was detected by two biochemical assays. We conclude that the sources of iron for H. influenzae are diverse. The significance of hydroxamate production and iron-related outer membrane proteins to H. influenzae iron acquisition is not yet clear. Images PMID:2964410

  19. Haemophilus influenzae type B in an immunocompetent, fully vaccinated ALL survivor.

    PubMed

    Nevin, John; Kanter Washko, Julie; Arnold, John

    2013-05-01

    A 7-year-old boy with a history of recurrent acute lymphoblastic leukemia (ALL), in remission, presented to primary care clinic after 2 days of progressive right hip pain with weight-bearing activities. He was otherwise asymptomatic at the time of presentation. Blood cultures revealed Gram-negative diplococci, which prompted an MRI that was significant for a hip joint effusion and femoral head bone marrow edema. The patient had no sick contacts and no significant past medical history other than ALL. The patient had been given all recommended childhood vaccinations. Arthrocentesis and needle biopsy of the femoral neck were not diagnostic for malignancy and revealed only mild hip joint inflammation, leading to a diagnosis of osteomyelitis. The organism in the original blood culture was identified as Haemophilus influenzae type b, β-lactamase negative. Review of the patient's medical records showed a history of complete immunization to Haemophilus influenzae type b. An immunologic evaluation was made to determine if the patient retained immunity from his other vaccinations. Pathogen-specific antibody testing revealed detectable antibodies to polio but not measles, mumps, rubella, varicella-zoster virus, tetanus, diphtheria, pertussis, or hepatitis B. This loss of immunologic memory appears to be a rarely described side effect of ALL chemotherapy. There is currently no protocol to evaluate the immunologic memory of patients who underwent chemotherapy for ALL or to revaccinate them after their treatment. It is unclear whether the loss of immunologic memory is genuinely rare or is underdiagnosed because affected patients are protected by herd immunity.

  20. Recombinant C-terminal 311 amino acids of HapS adhesin as a vaccine candidate for nontypeable Haemophilus influenzae: A study on immunoreactivity in Balb/C mouse.

    PubMed

    Tabatabaee Bafroee, Akram Sadat; Siadat, Seyed Davar; Mousavi, Seyed Fazlollah; Aghasadeghi, Mohammad Reza; Khorsand, Hashem; Nejati, Mehdi; Sadat, Seyed Mehdi; Mahdavi, Mehdi

    2016-09-01

    Hap, an auto-transporter protein, is an antigenically conserved adhesion protein which is present on both typeable and nontypeable Haemophilus influenzae. This protein has central role in bacterial attachment to respiratory tract epithelial cells. A 1000bp C-terminal fragment of Hap passenger domain (HapS) from nontypeable Haemophilus influenzae was cloned into a prokaryotic expression vector, pET-24a. BALB/c mice were immunized subcutaneously with purified rC-HapS. Serum IgG responses to purified rC-HapS, serum IgG subclasses were determined by ELISA and functional activity of antibodies was examined by Serum Bactericidal Assay. The output of rC-HapS was approximately 62% of the total bacterial proteins. Serum IgG responses were significantly increased in immunized group with rC-HapS mixed with Freund's adjuvant in comparison with control groups. Analysis of the serum IgG subclasses showed that the IgG1 subclass was predominant after subcutaneous immunization in BALB/c mice (IgG2a/IgG1 < 1). The sera from rC-HapS immunized animals were strongly bactericidal against nontypeable Haemophilus influenzae. These results suggest that rC-HapS may be a potential vaccine candidate for nontypeable Haemophilus influenzae. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. [Haemophilus influenzae type b meningitis in a vaccinated, immunocompetent infant with reactive arthritis].

    PubMed

    Nystrup, Kristin Brønnum; Wilms, Line Kønig

    2015-01-26

    Due to the excellent immunogenicity of the Haemophilus influenzae type b (Hib) conjugate vaccines, vaccine failures are rarely seen in patients following the recommended national immunization programmes. We present an infant with Hib meningitis despite relevant prophylaxis, without known risk factors such as medical co-morbidity, immunosuppression, immunoglobulin deficiency or prematurity. Later, a reactive arthritis developed. In conclusion, Hib-meningitis can occur in vaccinated, immunocompetent patients, and antibiotics covering Hib should be chosen in patients presenting with meningitis.

  2. Development of a Serological Test for Haemophilus ducreyi for Seroprevalence Studies

    PubMed Central

    Elkins, Christopher; Yi, Kyungcheol; Olsen, Bonnie; Thomas, Christopher; Thomas, Kevin; Morse, Stephen

    2000-01-01

    We developed a new enzyme immunoassay (rpEIA) for use in determining the seroprevalence of chancroid. Three highly conserved outer membrane proteins from Haemophilus ducreyi strain 35000 were cloned, overexpressed, and purified from Escherichia coli for use as antigens in the rpEIA. Serum specimens from patients with and without chancroid were assayed to determine optimum sensitivity and specificity and to establish cutoff values. On the basis of these data, rpEIA was found to be both sensitive and specific when used to test a variety of serum specimens from patients with genital ulcers and urethritis and from healthy blood donors. PMID:10747137

  3. Postantibiotic Effects of ABT-773 and Amoxicillin-Clavulanate against Streptococcus pneumoniae and Haemophilus influenzae

    PubMed Central

    Neuhauser, Melinda M.; Prause, Jennifer L.; Danziger, Larry H.; Pendland, Susan L.

    2001-01-01

    This study determined the postantibiotic effect (PAE) of ABT-773 versus that of amoxicillin-clavulanate against clinical isolates of Streptococcus pneumoniae and Haemophilus influenzae. The PAEs of ABT-773 and amoxicillin-clavulanate ranged from 2.3 to 6.0 h and 0 to 2.2 h against S. pneumoniae and from 2.7 to 9.1 h and 0 to 0.8 h against H. influenzae, respectively. PMID:11709352

  4. Effectiveness of haemophilus influenzae type B conjugate vaccine for prevention of meningitis in Senegal.

    PubMed

    Fleming, Jessica A; Dieye, Yakou; Ba, Ousseynou; Mutombo wa Mutombo, Boniface; Diallo, Ndiouga; Faye, Pape Coumba; Ba, Mamadou; Cisse, Moussa Fafa; Diallo, Aissatou Gaye; Ba, Mady; Slack, Mary P E; Weiss, Noel S

    2011-05-01

    A total of 24 cases of hospitalized, laboratory-confirmed Haemophilus influenzae type b (Hib) meningitis were identified through a regional pediatric bacterial meningitis surveillance system. Each case was matched by age and residence to 4 neighborhood controls. The adjusted vaccine effectiveness for ≥ 2 doses was 95.8% (95% confidence interval, 67.9%-99.4%). Hib vaccine appears to be highly effective in preventing Hib meningitis in Senegal.

  5. Susceptibility of Nontypeable Haemophilus influenzae to Human β-Defensins Is Influenced by Lipooligosaccharide Acylation

    PubMed Central

    Starner, Timothy D.; Swords, W. Edward; Apicella, Michael A.; McCray, Paul B.

    2002-01-01

    Nontypeable Haemophilus influenzae (NTHI) lipooligosaccharide htrB mutants exhibited greater than 45-fold-increased sensitivity to human β-defensin 2 (HBD-2) compared to the wild type. Complementation by htrB in trans to acylation competence reversed this increased sensitivity. In contrast, NTHI was more susceptible to HBD-3 and showed no changes in sensitivity as a result of lipooligosaccharide mutations in oligosaccharide and lipid A biosynthesis genes. PMID:12183584

  6. Maternal and perinatal factors associated with subsequent meningococcal, Haemophilus or enteroviral meningitis in children: database study.

    PubMed

    Goldacre, M J; Wotton, C J; Maisonneuve, J J

    2014-02-01

    We used a database of 248 659 births, with follow-up to subsequent disease, in the Oxford record linkage archive (1979-1999) to study the influence of family, maternal, and perinatal factors on subsequent hospital admission for meningococcal, Haemophilus, and enteroviral meningitis in the children. In this summary, we report key findings that were significant in multivariate analysis. Meningococcal meningitis was significantly associated with maternal smoking [odds ratio (OR) 2·1, 95% confidence interval (CI) 1·2-3·7]. Haemophilus meningitis was associated with having older siblings (e.g. second child compared to first-born, OR 3·3, 95% CI 2·0-5·6). Enteroviral meningitis was associated with low birth weight (OR 2·2, 95% CI 1·3-3·6) and male sex (OR 1·7, 95% CI 1·2-2·3). The mothers of six of the 312 children with enteroviral meningitis had previously had enteroviral meningitis themselves. We concluded that several maternal characteristics influence the risk of these types of meningitis.

  7. Evaluation of introduction of the Haemophilus influenzae vaccine in Côte d’Ivoire

    PubMed

    Yohou, Kévin Sylvestre; Aka, Nicaise Lepri; Noufe, Soualihou; Douba, Alfred; Assi Assi, Bernard; Dagnan, Simplice N Cho

    2016-11-25

    Introduction: Côte d’Ivoire introduced the Haemophilus influenzae type b vaccine into the EPI in March 2009. Following this introduction, an evaluation was conducted in 2012 in order to evaluate the vaccine introduction process. Methods: Data collection methods consisted of document review, structured interviews and direct observation. This study collected information from six health region officials, 12 health districts and 36 healthcare institutions. Seventy-two mothers or child carers were also interviewed. Collected data were processed and analysed by Excel, Epi Info and SPSS. Results: A vaccine introduction plan was developed, but was not communicated at the operational level. The planned training for district health care providers was conducted eighteen months after introduction of the vaccine. None of the vaccinating centres had communication support about the new vaccine. Temperature recording was regularly performed in 92% of district deposits and 68% of vaccinating centres. Deteriorated vaccines were observed in 6% of vaccinating centres. Only 3.5% of parents had been informed about introduction of the vaccine. Increased immunization coverage for the third dose of pentavalent vaccine was observed in one half of health districts. Conclusion: Evaluation of the introduction of Haemophilus influenzae type b vaccine highlightsthe strengths and weaknesses of the health system and provides lessons for the introduction of other vaccines into the expanded programme on immunization.

  8. Antimicrobial susceptibility and serotypes of Actinobacillus (Haemophilus) pleuropneumoniae recovered from Missouri swine.

    PubMed

    Fales, W H; Morehouse, L G; Mittal, K R; Bean-Knudsen, C; Nelson, S L; Kintner, L D; Turk, J R; Turk, M A; Brown, T P; Shaw, D P

    1989-01-01

    The antimicrobial susceptibility of 73 Actinobacillus (Haemophilus) pleuropneumoniae isolates from swine in Missouri was determined with a microdilution minimal inhibitory concentration test system. Serotyping was accomplished by means of co-agglutination. Serotype 1 (39/73) and serotype 5 (30/73) were commonly found, whereas serotype 7 (4/73) was infrequently encountered. Most isolates (MIC90) were found susceptible to ampicillin (amoxicillin), cephalothin, penicillin, erythromycin, gentamicin, and kanamycin. Marked resistance was found with oxytetracycline, tylosin, and sulfadimethoxine. The data indicate that use of ampicillin (amoxicillin) or penicillin may correlate well with the favorable outcome of treatment.

  9. In vitro capability of faropenem to select for resistant mutants of Streptococcus pneumoniae and Haemophilus influenzae.

    PubMed

    Kosowska-Shick, Klaudia; Clark, Catherine; Credito, Kim; Dewasse, Bonifacio; Beachel, Linda; Ednie, Lois; Appelbaum, Peter C

    2008-02-01

    When tested against nine strains of pneumococci and six of Haemophilus influenzae of various resistotypes, faropenem failed to select for resistant mutants after 50 days of consecutive subculture in subinhibitory concentrations. Faropenem also yielded low rates of spontaneous mutations against all organisms of both species. By comparison, resistant clones were obtained with macrolides, ketolides, and quinolones.

  10. Identification of a group of Haemophilus influenzae penicillin-binding proteins that may have complementary physiological roles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Malouin, F.; Parr, T.R. Jr.; Bryan, L.E.

    (35S)penicillin bound to different Haemophilus influenzae proteins in assays performed at 20, 37, or 42{degrees}C. Penicillin-binding proteins 3a, 3b, 4, and 4' formed a group characterized by their affinity for moxalactam, cefotaxime, and piperacillin. Penicillin-binding protein 4' showed specific properties that may reflect its complementary role in septation.

  11. Rapid Differentiation of Haemophilus influenzae and Haemophilus haemolyticus by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry with ClinProTools Mass Spectrum Analysis

    PubMed Central

    Cheng, Vincent C. C.; Wong, Chun-Pong; Wong, Sally C. Y.; Yam, Wing-Cheong

    2017-01-01

    ABSTRACT Haemophilus influenzae is associated with severe invasive disease, while Haemophilus haemolyticus is considered part of the commensal flora in the human respiratory tract. Although the addition of a custom mass spectrum library into the matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system could improve identification of these two species, the establishment of such a custom database is technically complicated and requires a large amount of resources, which most clinical laboratories cannot afford. In this study, we developed a mass spectrum analysis model with 7 mass peak biomarkers for the identification of H. influenzae and H. haemolyticus using the ClinProTools software. We evaluated the diagnostic performance of this model using 408 H. influenzae and H. haemolyticus isolates from clinical respiratory specimens from 363 hospitalized patients and compared the identification results with those obtained with the Bruker IVD MALDI Biotyper. The IVD MALDI Biotyper identified only 86.9% of H. influenzae (311/358) and 98.0% of H. haemolyticus (49/50) clinical isolates to the species level. In comparison, the ClinProTools mass spectrum model could identify 100% of H. influenzae (358/358) and H. haemolyticus (50/50) clinical strains to the species level and significantly improved the species identification rate (McNemar's test, P < 0.0001). In conclusion, the use of ClinProTools demonstrated an alternative way for users lacking special expertise in mass spectrometry to handle closely related bacterial species when the proprietary spectrum library failed. This approach should be useful for the differentiation of other closely related bacterial species. PMID:28637909

  12. Characterization of Genetic and Phenotypic Diversity of Invasive Nontypeable Haemophilus influenzae

    PubMed Central

    Erwin, Alice L.; Nelson, Kevin L.; Mhlanga-Mutangadura, Tendai; Bonthuis, Paul J.; Geelhood, Jennifer L.; Morlin, Gregory; Unrath, William C. T.; Campos, Jose; Crook, Derrick W.; Farley, Monica M.; Henderson, Frederick W.; Jacobs, Richard F.; Mühlemann, Kathrin; Satola, Sarah W.; van Alphen, Loek; Golomb, Miriam; Smith, Arnold L.

    2005-01-01

    The ability of unencapsulated (nontypeable) Haemophilus influenzae (NTHi) to cause systemic disease in healthy children has been recognized only in the past decade. To determine the extent of similarity among invasive nontypeable isolates, we compared strain R2866 with 16 additional NTHi isolates from blood and spinal fluid, 17 nasopharyngeal or throat isolates from healthy children, and 19 isolates from middle ear aspirates. The strains were evaluated for the presence of several genetic loci that affect bacterial surface structures and for biochemical reactions that are known to differ among H. influenzae strains. Eight strains, including four blood isolates, shared several properties with R2866: they were biotype V (indole and ornithine decarboxylase positive, urease negative), contained sequence from the adhesin gene hia, and lacked a genetic island flanked by the infA and ksgA genes. Multilocus sequence typing showed that most biotype V isolates belonged to the same phylogenetic cluster as strain R2866. When present, the infA-ksgA island contains lipopolysaccharide biosynthetic genes, either lic2B and lic2C or homologs of the losA and losB genes described for Haemophilus ducreyi. The island was found in most nasopharyngeal and otitis isolates but was absent from 40% of invasive isolates. Overall, the 33 hmw-negative isolates were much more likely than hmw-containing isolates to have tryptophanase, ornithine decarboxylase, or lysine decarboxylase activity or to contain the hif genes. We conclude (i) that invasive isolates are genetically and phenotypically diverse and (ii) that certain genetic loci of NTHi are frequently found in association among NTHi strains. PMID:16113304

  13. Histophilus somni host-parasite relationships.

    PubMed

    Corbeil, Lynette B

    2007-12-01

    Histophilus somni (Haemophilus somnus) is one of the key bacterial pathogens involved in the multifactorial etiology of the Bovine Respiratory Disease Complex. This Gram negative pleomorphic rod also causes bovine septicemia, thrombotic meningencephalitis, myocarditis, arthritis, abortion and infertility, as well as disease in sheep, bison and bighorn sheep. Virulence factors include lipooligosaccharide, immunoglobulin binding proteins (as a surface fibrillar network), a major outer membrane protein (MOMP), other outer membrane proteins (OMPs) and exopolysaccharide. Histamine production, biofilm formation and quorum sensing may also contribute to pathogenesis. Antibodies are very important in protection as shown in passive protection studies. The lack of long-term survival of the organism in macrophages, unlike facultative intracellular bacteria, also suggests that antibodies should be critical in protection. Of the immunoglobulin classes, IgG2 antibodies are most implicated in protection and IgE antibodies in immunopathogenesis. The immunodominant antigen recognized by IgE is the MOMP and by IgG2 is a 40 kDa OMP. Pathogenetic synergy of bovine respiratory syncytial virus (BRSV) and H. somni in calves can be attributed, in part at least, to the higher IgE anti-MOMP antibody responses in dually infected calves. Other antigens are probably involved in stimulating host defense or immunopathology as well.

  14. Haemophilus parainfluenzae meningitis in an adult associated with acute otitis media.

    PubMed

    Cardines, Rita; Giufrè, Maria; Ciofi degli Atti, Marta Luisa; Accogli, Marisa; Mastrantonio, Paola; Cerquetti, Marina

    2009-04-01

    A case of Haemophilus parainfluenzae meningitis in a woman with a 3-day history of acute otitis media is reported. Her medical history included bladder cancer surgery. Unequivocal identification of the isolate was obtained by using molecular techniques such as 16S rRNA sequencing besides to conventional culture methods. To investigate bacterial virulent traits possibly related to invasive properties, in vitro serum resistance of our isolate was analyzed, but it was found serum susceptible. Our study demonstrates that H. parainfluenzae can be considered an opportunistic pathogen able to cause life-threatening infections not only in children but also in patients with underlying conditions.

  15. [Isolation of Haemophilus influenzae serotypes from deep sites in sick children].

    PubMed

    Gatti, B M; Ramirez Gronda, G A; Etchevarría, M; Vescina, C M; Varea, A M; González Ayala, S E

    2004-01-01

    Haemophilus influenzae (Hi) is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.

  16. [Haemophilus influenzae type b in Italy--after thirty years of vaccination may we lower our guard?].

    PubMed

    Terracciano, Elisa; Zaratti, Laura; Franco, Elisabetta

    2015-01-01

    Haemophilus influenzae b (Hib) is responsible for meningitis, systemic infections and acute respiratory illness, especially in children. The use of the conjugate vaccines against Hib reduced the incidence of the disease worldwide. In Italy, after the decrease resulted from vaccination, the disease may reappear due to the reduction in vaccination coverage, the presence of infections in adults and vaccine failures.

  17. Detection of Haemophilus influenzae in respiratory secretions from pneumonia patients by quantitative real-time polymerase chain reaction.

    PubMed

    Abdeldaim, Guma M K; Strålin, Kristoffer; Kirsebom, Leif A; Olcén, Per; Blomberg, Jonas; Herrmann, Björn

    2009-08-01

    A quantitative real-time polymerase chain reaction (PCR) based on the omp P6 gene was developed to detect Haemophilus influenzae. Its specificity was determined by analysis of 29 strains of 11 different Haemophilus spp. and was compared with PCR assays having other target genes: rnpB, 16S rRNA, and bexA. The method was evaluated on nasopharyngeal aspirates from 166 adult patients with community-acquired pneumonia. When 10(4) DNA copies/mL was used as cutoff limit for the method, P6 PCR had a sensitivity of 97.5% and a specificity of 96.0% compared with the culture. Of 20 culture-negative but P6 PCR-positive cases, 18 were confirmed by fucK PCR as H. influenzae. Five (5.9%) of 84 nasopharyngeal aspirates from adult controls tested PCR positive. We conclude that the P6 real-time PCR is both sensitive and specific for identification of H. influenzae in respiratory secretions. Quantification facilitates discrimination between disease-causing H. influenzae strains and commensal colonization.

  18. Photodynamic Action on Native and Denatured Transforming Deoxyribonucleic Acid from Haemophilus influenzae

    PubMed Central

    León, Manuel Ponce-De; Cabrera-Juárez, Emiliano

    1970-01-01

    The photodynamic inactivation of native or denatured transforming deoxyribonucleic acid (DNA) from Haemophilus influenzae is described. The inactivation at the same pH was higher for denatured than native DNA. At acidic pH, the inactivation both for native and denatured DNA was faster than at alkaline pH. The guanine content of photoinactivated native DNA at neutral pH was less than untreated DNA. The inactivation of biological activity was more extensive than the alteration of guanine. The absorption spectrum of photoinactivated native or denatured DNA was only slightly different than the control DNA at the different experimental conditions. PMID:5309576

  19. In Vitro Capability of Faropenem To Select for Resistant Mutants of Streptococcus pneumoniae and Haemophilus influenzae▿ †

    PubMed Central

    Kosowska-Shick, Klaudia; Clark, Catherine; Credito, Kim; Dewasse, Bonifacio; Beachel, Linda; Ednie, Lois; Appelbaum, Peter C.

    2008-01-01

    When tested against nine strains of pneumococci and six of Haemophilus influenzae of various resistotypes, faropenem failed to select for resistant mutants after 50 days of consecutive subculture in subinhibitory concentrations. Faropenem also yielded low rates of spontaneous mutations against all organisms of both species. By comparison, resistant clones were obtained with macrolides, ketolides, and quinolones. PMID:18086853

  20. Partial heterologous protection against Glässer’s disease in pigs colonized with an avirulent isolate of Haemophilus parasuis

    USDA-ARS?s Scientific Manuscript database

    Haemophilus parasuis is a Gram-negative bacterium belonging to the Pasteurellaceae family. This bacterium can exist as a commensal in the upper respiratory tract in swine, but can also cause pneumonia and can systemically invade causing Glässer’s disease, which is characterized by polyserositis, men...

  1. Rapid Differentiation of Haemophilus influenzae and Haemophilus haemolyticus by Use of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry with ClinProTools Mass Spectrum Analysis.

    PubMed

    Chen, Jonathan H K; Cheng, Vincent C C; Wong, Chun-Pong; Wong, Sally C Y; Yam, Wing-Cheong; Yuen, Kwok-Yung

    2017-09-01

    Haemophilus influenzae is associated with severe invasive disease, while Haemophilus haemolyticus is considered part of the commensal flora in the human respiratory tract. Although the addition of a custom mass spectrum library into the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system could improve identification of these two species, the establishment of such a custom database is technically complicated and requires a large amount of resources, which most clinical laboratories cannot afford. In this study, we developed a mass spectrum analysis model with 7 mass peak biomarkers for the identification of H. influenzae and H. haemolyticus using the ClinProTools software. We evaluated the diagnostic performance of this model using 408 H. influenzae and H. haemolyticus isolates from clinical respiratory specimens from 363 hospitalized patients and compared the identification results with those obtained with the Bruker IVD MALDI Biotyper. The IVD MALDI Biotyper identified only 86.9% of H. influenzae (311/358) and 98.0% of H. haemolyticus (49/50) clinical isolates to the species level. In comparison, the ClinProTools mass spectrum model could identify 100% of H. influenzae (358/358) and H. haemolyticus (50/50) clinical strains to the species level and significantly improved the species identification rate (McNemar's test, P < 0.0001). In conclusion, the use of ClinProTools demonstrated an alternative way for users lacking special expertise in mass spectrometry to handle closely related bacterial species when the proprietary spectrum library failed. This approach should be useful for the differentiation of other closely related bacterial species. Copyright © 2017 American Society for Microbiology.

  2. Population Structure in Nontypeable Haemophilus influenzae

    PubMed Central

    LaCross, Nathan C.; Marrs, Carl F.; Gilsdorf, Janet R.

    2013-01-01

    Nontypeable Haemophilus influenzae (NTHi) frequently colonize the human pharynx asymptomatically, and are an important cause of otitis media in children. Past studies have identified typeable H. influenzae as being clonal, but the population structure of NTHi has not been extensively characterized. The research presented here investigated the diversity and population structure in a well-characterized collection of NTHi isolated from the middle ears of children with otitis media or the pharynges of healthy children in three disparate geographic regions. Multilocus sequence typing identified 109 unique sequence types among 170 commensal and otitis media-associated NTHi isolates from Finland, Israel, and the US. The largest clonal complex contained only five sequence types, indicating a high level of genetic diversity. The eBURST v3, ClonalFrame 1.1, and structure 2.3.3 programs were used to further characterize diversity and population structure from the sequence typing data. Little clustering was apparent by either disease state (otitis media or commensalism) or geography in the ClonalFrame phylogeny. Population structure was clearly evident, with support for eight populations when all 170 isolates were analyzed. Interestingly, one population contained only commensal isolates, while two others consisted solely of otitis media isolates, suggesting associations between population structure and disease. PMID:23266487

  3. Population-based incidence of invasive haemophilus influenzae and pneumococcal diseases before the introduction of vaccines in Japan.

    PubMed

    Nakamura, Riko; Togashi, Takehiro

    2013-12-01

    Before the introduction of vaccines, the incidence of bacterial meningitis among children aged 28 days to 5 years was 8.48, Haemophilus influenzae type-b meningitis was 5.65 and Streptococcus pneumoniae meningitis was 1.85 per 100,000 person-years in Hokkaido, Japan. The incidence of bacteremia caused by S. pneumoniae was 60.15 and H. influenzae was 18.80.

  4. Relationship between clinical site of isolation and ability to form biofilms in vitro in nontypeable Haemophilus influenzae.

    PubMed

    Obaid, Najla A; Jacobson, Glenn A; Tristram, Stephen

    2015-03-01

    Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen associated with a range of infections, including various lower respiratory infections, otitis media, and conjunctivitis. There is some debate as to whether or not NTHi produces biofilms and, if so, whether or not this is relevant to pathogenesis. Although many studies have examined the association between in vitro biofilm formation and isolates from a specific infection type, few have made comparisons from isolates from a broad range of isolates grouped by clinical source. In our study 50 NTHi from different clinical sources, otitis media, conjunctivitis, lower respiratory tract infections in both cystic fibrosis and non-cystic fibrosis patients, and nasopharyngeal carriage, plus 10 nasopharyngeal isolates of the commensal Haemophilus haemolyticus were tested for the ability to form biofilm by using a static microtitre plate crystal violet assay. A high degree of variation in biofilm forming ability was observed across all isolates, with no statistically significant differences observed between the groups, with the exception of the isolates from conjunctivitis. These isolates had uniformly lower biofilm forming ability compared with isolates from the other groups (p < 0.005).

  5. Characterization of an antimicrobial peptide produced by Bacillus subtilis subsp. spizezinii showing inhibitory activity towards Haemophilus parasuis.

    PubMed

    Teixeira, Mário Lettieri; Dalla Rosa, Andréia; Brandelli, Adriano

    2013-05-01

    Haemophilus parasuis is the pathogen that causes Glässer's disease, a major illness affecting young pigs. The aim of this work was to investigate the antagonistic activity of antimicrobial substances produced by Bacillus species against H. parasuis. Among the tested strains, only Bacillus subtilis ATCC 6633 inhibited H. parasuis growth. The antibacterial substance was purified by ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-50 and ion-exchange chromatography on DEAE-cellulose. The purification was about 100-fold with a yield of 0.33 %. The purified substance was resistant up to 80 °C and pH ranging 3-7, but the substance lost its activity when it was treated with proteases. The peptide had a molecular mass of 1083 Da and its sequence was determined by MS as NRWCFAGDD, which showed no homology with other known antimicrobial peptides. The complete inhibition of H. parasuis growth was observed at 20 µg peptide ml(-1) after 20 min of exposure. The peptide obtained by chemical synthesis also showed antimicrobial activity on H. parasuis. The identification of antimicrobial substances that can be effective against H. parasuis is very relevant to combat this pathogen that causes important losses in swine production.

  6. Antigen detection and immunological typing of Haemophilus ducreyi with a specific rabbit polyclonal serum.

    PubMed Central

    Roggen, E L; Pansaerts, R; Van Dyck, E; Piot, P

    1993-01-01

    A rabbit polyclonal serum was raised against the 29-kDa species-specific marker, as well as the 30- to 34-kDa immunotype-specific markers of Haemophilus ducreyi described elsewhere (E. Roggen, S. De Breucker, E. Van Dyck, and P. Piot, Infect. Immun. 60:590-595, 1992). These antigens were purified from a cocktail of H. ducreyi isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The immune serum reacted in enzyme-linked immunosorbent assay (ELISA) preferentially with H. ducreyi, at a titer as high as 50,000. To make it specific to H. ducreyi, nonspecific antibodies were removed by adsorption on a mixture of Haemophilus spp., Escherichia coli, Candida albicans, and Corynebacterium spp. In the 29- to 34-kDa region of immunoblot profiles from H. ducreyi isolates (n = 450), the adsorbed serum revealed essentially the same antigens as did a pool of well-characterized human sera. Yet, eight different immunotypes were observed. With this rabbit polyclonal serum, an ELISA-based antigen detection test was developed. The adsorbed serum reacted specifically with all H. ducreyi isolates tested (n = 450), but not with other bacterial species (n = 15). This test was evaluated with a limited number of clinical specimens from African patients with culture-proven chancroid and no evidence for any other ulcerating etiology (n = 10) and a number of chancroid-negative control patients from Belgium (n = 20). Within this context, the test yielded a sensitivity and specificity of 100%. Images PMID:8349759

  7. Basic Characterization of Natural Transformation in a Highly Transformable Haemophilus parasuis Strain SC1401

    PubMed Central

    Dai, Ke; He, Lvqin; Chang, Yung-Fu; Cao, Sanjie; Zhao, Qin; Huang, Xiaobo; Wu, Rui; Huang, Yong; Yan, Qigui; Han, Xinfeng; Ma, Xiaoping; Wen, Xintian; Wen, Yiping

    2018-01-01

    Haemophilus parasuis causes Glässer's disease and pneumonia, incurring serious economic losses in the porcine industry. In this study, natural competence was investigated in H. parasuis. We found competence genes in H. parasuis homologous to ones in Haemophilus influenzae and a high consensus battery of Sxy-dependent cyclic AMP (cAMP) receptor protein (CRP-S) regulons using bioinformatics. High rates of natural competence were found from the onset of stationary-phase growth condition to mid-stationary phase (OD600 from 0.29 to 1.735); this rapidly dropped off as cells reached mid-stationary phase (OD600 from 1.735 to 1.625). As a whole, bacteria cultured in liquid media were observed to have lower competence levels than those grown on solid media plates. We also revealed that natural transformation in this species is stable after 200 passages and is largely dependent on DNA concentration. Transformation competition experiments showed that heterogeneous DNA cannot outcompete intraspecific natural transformation, suggesting an endogenous uptake sequence or other molecular markers may be important in differentiating heterogeneous DNA. We performed qRT-PCR targeting multiple putative competence genes in an effort to compare bacteria pre-cultured in TSB++ vs. TSA++ and SC1401 vs. SH0165 to determine expression profiles of the homologs of competence-genes in H. influenzae. Taken together, this study is the first to investigate natural transformation in H. parasuis based on a highly naturally transformable strain SC1401. PMID:29473023

  8. Haemophilus parainfluenzae Strain ATCC 33392 Forms Biofilms In Vitro and during Experimental Otitis Media Infections

    PubMed Central

    Pang, Bing

    2017-01-01

    ABSTRACT Haemophilus parainfluenzae is a nutritionally fastidious, Gram-negative bacterium with an oropharyngeal/nasopharyngeal carriage niche that is associated with a range of opportunistic infections, including infectious endocarditis and otitis media (OM). These infections are often chronic/recurrent in nature and typically involve bacterial persistence within biofilm communities that are highly resistant to host clearance. This study addresses the primary hypothesis that H. parainfluenzae forms biofilm communities that are important determinants of persistence in vivo. The results from in vitro biofilm studies confirmed that H. parainfluenzae formed biofilm communities within which the polymeric matrix was mainly composed of extracellular DNA and proteins. Using a chinchilla OM infection model, we demonstrated that H. parainfluenzae formed surface-associated biofilm communities containing bacterial and host components that included neutrophil extracellular trap (NET) structures and that the bacteria mainly persisted in these biofilm communities. We also used this model to examine the possible interaction between H. parainfluenzae and its close relative Haemophilus influenzae, which is also commonly carried within the same host environments and can cause OM. The results showed that coinfection with H. influenzae promoted clearance of H. parainfluenzae from biofilm communities during OM infection. The underlying mechanisms for bacterial persistence and biofilm formation by H. parainfluenzae and knowledge about the survival defects of H. parainfluenzae during coinfection with H. influenzae are topics for future work. PMID:28674033

  9. Haemophilus parainfluenzae Strain ATCC 33392 Forms Biofilms In Vitro and during Experimental Otitis Media Infections.

    PubMed

    Pang, Bing; Swords, W Edward

    2017-09-01

    Haemophilus parainfluenzae is a nutritionally fastidious, Gram-negative bacterium with an oropharyngeal/nasopharyngeal carriage niche that is associated with a range of opportunistic infections, including infectious endocarditis and otitis media (OM). These infections are often chronic/recurrent in nature and typically involve bacterial persistence within biofilm communities that are highly resistant to host clearance. This study addresses the primary hypothesis that H. parainfluenzae forms biofilm communities that are important determinants of persistence in vivo The results from in vitro biofilm studies confirmed that H. parainfluenzae formed biofilm communities within which the polymeric matrix was mainly composed of extracellular DNA and proteins. Using a chinchilla OM infection model, we demonstrated that H. parainfluenzae formed surface-associated biofilm communities containing bacterial and host components that included neutrophil extracellular trap (NET) structures and that the bacteria mainly persisted in these biofilm communities. We also used this model to examine the possible interaction between H. parainfluenzae and its close relative Haemophilus influenzae , which is also commonly carried within the same host environments and can cause OM. The results showed that coinfection with H. influenzae promoted clearance of H. parainfluenzae from biofilm communities during OM infection. The underlying mechanisms for bacterial persistence and biofilm formation by H. parainfluenzae and knowledge about the survival defects of H. parainfluenzae during coinfection with H. influenzae are topics for future work. Copyright © 2017 American Society for Microbiology.

  10. Host-pathogen interplay of Haemophilus ducreyi.

    PubMed

    Janowicz, Diane M; Li, Wei; Bauer, Margaret E

    2010-02-01

    Haemophilus ducreyi, the causative agent of the sexually transmitted infection chancroid, is primarily a pathogen of human skin. During infection, H. ducreyi thrives extracellularly in a milieu of professional phagocytes and other antibacterial components of the innate and adaptive immune responses. This review summarizes our understanding of the interplay between this pathogen and its host that leads to development and persistence of disease. H. ducreyi expresses key virulence mechanisms to resist host defenses. The secreted LspA proteins are tyrosine-phosphorylated by host kinases, which may contribute to their antiphagocytic effector function. The serum resistance and adherence functions of DsrA map to separate domains of this multifunctional virulence factor. An influx transporter protects H. ducreyi from killing by the antimicrobial peptide LL37. Regulatory genes have been identified that may coordinate virulence factor expression during disease. Dendritic cells and natural killer cells respond to H. ducreyi and may be involved in determining the differential outcomes of infection observed in humans. A human model of H. ducreyi infection has provided insights into virulence mechanisms that allow this human-specific pathogen to survive immune pressures. Components of the human innate immune system may also determine the ultimate fate of H. ducreyi infection by driving either clearance of the organism or an ineffective response that allows disease progression.

  11. Lineage-specific Virulence Determinants of Haemophilus influenzae Biogroup aegyptius

    PubMed Central

    Strouts, Fiona R.; Power, Peter; Croucher, Nicholas J.; Corton, Nicola; van Tonder, Andries; Quail, Michael A.; Langford, Paul R.; Hudson, Michael J.; Parkhill, Julian; Bentley, Stephen D.

    2012-01-01

    An emergent clone of Haemophilus influenzae biogroup aegyptius (Hae) is responsible for outbreaks of Brazilian purpuric fever (BPF). First recorded in Brazil in 1984, the so-called BPF clone of Hae caused a fulminant disease that started with conjunctivitis but developed into septicemic shock; mortality rates were as high as 70%. To identify virulence determinants, we conducted a pan-genomic analysis. Sequencing of the genomes of the BPF clone strain F3031 and a noninvasive conjunctivitis strain, F3047, and comparison of these sequences with 5 other complete H. influenzae genomes showed that >77% of the F3031 genome is shared among all H. influenzae strains. Delineation of the Hae accessory genome enabled characterization of 163 predicted protein-coding genes; identified differences in established autotransporter adhesins; and revealed a suite of novel adhesins unique to Hae, including novel trimeric autotransporter adhesins and 4 new fimbrial operons. These novel adhesins might play a critical role in host–pathogen interactions. PMID:22377449

  12. Systems properties of the Haemophilus influenzae Rd metabolic genotype.

    PubMed

    Edwards, J S; Palsson, B O

    1999-06-18

    Haemophilus influenzae Rd was the first free-living organism for which the complete genomic sequence was established. The annotated sequence and known biochemical information was used to define the H. influenzae Rd metabolic genotype. This genotype contains 488 metabolic reactions operating on 343 metabolites. The stoichiometric matrix was used to determine the systems characteristics of the metabolic genotype and to assess the metabolic capabilities of H. influenzae. The need to balance cofactor and biosynthetic precursor production during growth on mixed substrates led to the definition of six different optimal metabolic phenotypes arising from the same metabolic genotype, each with different constraining features. The effects of variations in the metabolic genotype were also studied, and it was shown that the H. influenzae Rd metabolic genotype contains redundant functions under defined conditions. We thus show that the synthesis of in silico metabolic genotypes from annotated genome sequences is possible and that systems analysis methods are available that can be used to analyze and interpret phenotypic behavior of such genotypes.

  13. Structure-based functional annotation of putative conserved proteins having lyase activity from Haemophilus influenzae.

    PubMed

    Shahbaaz, Mohd; Ahmad, Faizan; Imtaiyaz Hassan, Md

    2015-06-01

    Haemophilus influenzae is a small pleomorphic Gram-negative bacteria which causes several chronic diseases, including bacteremia, meningitis, cellulitis, epiglottitis, septic arthritis, pneumonia, and empyema. Here we extensively analyzed the sequenced genome of H. influenzae strain Rd KW20 using protein family databases, protein structure prediction, pathways and genome context methods to assign a precise function to proteins whose functions are unknown. These proteins are termed as hypothetical proteins (HPs), for which no experimental information is available. Function prediction of these proteins would surely be supportive to precisely understand the biochemical pathways and mechanism of pathogenesis of Haemophilus influenzae. During the extensive analysis of H. influenzae genome, we found the presence of eight HPs showing lyase activity. Subsequently, we modeled and analyzed three-dimensional structure of all these HPs to determine their functions more precisely. We found these HPs possess cystathionine-β-synthase, cyclase, carboxymuconolactone decarboxylase, pseudouridine synthase A and C, D-tagatose-1,6-bisphosphate aldolase and aminodeoxychorismate lyase-like features, indicating their corresponding functions in the H. influenzae. Lyases are actively involved in the regulation of biosynthesis of various hormones, metabolic pathways, signal transduction, and DNA repair. Lyases are also considered as a key player for various biological processes. These enzymes are critically essential for the survival and pathogenesis of H. influenzae and, therefore, these enzymes may be considered as a potential target for structure-based rational drug design. Our structure-function relationship analysis will be useful to search and design potential lead molecules based on the structure of these lyases, for drug design and discovery.

  14. Genome-Scale Approaches to Identify Genes Essential for Haemophilus influenzae Pathogenesis

    PubMed Central

    Wong, Sandy M. S.; Akerley, Brian J.

    2012-01-01

    Haemophilus influenzae is a Gram-negative bacterium that has no identified natural niche outside of the human host. It primarily colonizes the nasopharyngeal mucosa in an asymptomatic mode, but has the ability to disseminate to other anatomical sites to cause otitis media, upper, and lower respiratory tract infections, septicemia, and meningitis. To persist in diverse environments the bacterium must exploit and utilize the nutrients and other resources available in these sites for optimal growth/survival. Recent evidence suggests that regulatory factors that direct such adaptations also control virulence determinants required to resist and evade immune clearance mechanisms. In this review, we describe the recent application of whole-genome approaches that together provide insight into distinct survival mechanisms of H. influenzae in the context of different sites of pathogenesis. PMID:22919615

  15. Genome-scale approaches to identify genes essential for Haemophilus influenzae pathogenesis.

    PubMed

    Wong, Sandy M S; Akerley, Brian J

    2012-01-01

    Haemophilus influenzae is a Gram-negative bacterium that has no identified natural niche outside of the human host. It primarily colonizes the nasopharyngeal mucosa in an asymptomatic mode, but has the ability to disseminate to other anatomical sites to cause otitis media, upper, and lower respiratory tract infections, septicemia, and meningitis. To persist in diverse environments the bacterium must exploit and utilize the nutrients and other resources available in these sites for optimal growth/survival. Recent evidence suggests that regulatory factors that direct such adaptations also control virulence determinants required to resist and evade immune clearance mechanisms. In this review, we describe the recent application of whole-genome approaches that together provide insight into distinct survival mechanisms of H. influenzae in the context of different sites of pathogenesis.

  16. Diesel exhaust alters the response of cultured primary bronchial epithelial cells from patients with chronic obstructive pulmonary disease (COPD) to non-typeable Haemophilus influenzae.

    PubMed

    Zarcone, Maria C; van Schadewijk, Annemarie; Duistermaat, Evert; Hiemstra, Pieter S; Kooter, Ingeborg M

    2017-01-28

    Exacerbations constitute a major cause of morbidity and mortality in patients suffering from chronic obstructive pulmonary disease (COPD). Both bacterial infections, such as those with non-typeable Haemophilus influenzae (NTHi), and exposures to diesel engine emissions are known to contribute to exacerbations in COPD patients. However, the effect of diesel exhaust (DE) exposure on the epithelial response to microbial stimulation is incompletely understood, and possible differences in the response to DE of epithelial cells from COPD patients and controls have not been studied. Primary bronchial epithelial cells (PBEC) were obtained from age-matched COPD patients (n = 7) and controls (n = 5). PBEC were cultured at the air-liquid interface (ALI) to achieve mucociliary differentiation. ALI-PBECs were apically exposed for 1 h to a stream of freshly generated whole DE or air. Exposure was followed by 3 h incubation in presence or absence of UV-inactivated NTHi before analysis of epithelial gene expression. DE alone induced an increase in markers of oxidative stress (HMOX1, 50-100-fold) and of the integrated stress response (CHOP, 1.5-2-fold and GADD34, 1.5-fold) in cells from both COPD patients and controls. Exposure of COPD cultures to DE followed by NTHi caused an additive increase in GADD34 expression (up to 3-fold). Importantly, DE caused an inhibition of the NTHi-induced expression of the antimicrobial peptide S100A7, and of the chaperone protein HSP5A/BiP. Our findings show that DE exposure of differentiated primary airway epithelial cells causes activation of the gene expression of HMOX1 and markers of integrated stress response to a similar extent in cells from COPD donors and controls. Furthermore, DE further increased the NTHi-induced expression of GADD34, indicating a possible enhancement of the integrated stress response. DE reduced the NTHi-induced expression of S100A7. These data suggest that DE exposure may cause adverse health effects in part by

  17. Activities of a new oral streptogramin, XRP 2868, compared to those of other agents against Streptococcus pneumoniae and haemophilus species.

    PubMed

    Pankuch, Glenn A; Kelly, Linda M; Lin, Gengrong; Bryskier, Andre; Couturier, Catherine; Jacobs, Michael R; Appelbaum, Peter C

    2003-10-01

    MIC methodology was used to test the antibacterial activity of XRP 2868, a new oral combination of two semisynthetic streptogramins, RPR 132552A and RPR 202868, compared to activities of other antibacterial agents against pneumococci, Haemophilus influenzae, and Haemophilus parainfluenzae. For 261 pneumococci, XRP 2868 and pristinamycin MICs were similar, irrespective of penicillin G and erythromycin A susceptibilities (MIC at which 50% of isolates were inhibited [MIC(50)], 0.25 micro g/ml; MIC(90), 0.5 micro g/ml), while quinupristin/dalfopristin had MICs which were 1 to 2 dilutions higher. Single components of both XRP 2868 and quinupristin/dalfopristin had higher MICs. Erythromycin A, azithromycin, clarithromycin, and clindamycin MICs were higher for penicillin G-intermediate and -resistant than -susceptible pneumococci. Against 150 H. influenzae strains, all compounds tested had unimodal MIC distributions. XRP 2868 had an overall MIC(50) of 0.25 micro g/ml and an MIC(90) of 1.0 micro g/ml, with no differences between beta-lactamase-positive, beta-lactamase-negative, and beta-lactamase-negative ampicillin-resistant strains. Of note was the similarly low activity of one of its components, RPR 132552A. Pristinamycin and quinupristin/dalfopristin had MICs of 0.125 to 8.0 micro g/ml; quinupristin alone had MICs of 8.0 to >64.0 micro g/ml, and dalfopristin had MICs of 1.0 to >64.0 micro g/ml. Erythromycin A, azithromycin, and clarithromycin had modal MICs of 4.0, 1.0, and 8.0 micro g/ml, respectively. MICs of all compounds against H. parainfluenzae were 1 to 2 dilutions higher than against H. influenzae. XRP 2868 showed potent activity against pneumococci and Haemophilus strains irrespective of their susceptibility to other agents.

  18. Activities of a New Oral Streptogramin, XRP 2868, Compared to Those of Other Agents against Streptococcus pneumoniae and Haemophilus Species

    PubMed Central

    Pankuch, Glenn A.; Kelly, Linda M.; Lin, Gengrong; Bryskier, Andre; Couturier, Catherine; Jacobs, Michael R.; Appelbaum, Peter C.

    2003-01-01

    MIC methodology was used to test the antibacterial activity of XRP 2868, a new oral combination of two semisynthetic streptogramins, RPR 132552A and RPR 202868, compared to activities of other antibacterial agents against pneumococci, Haemophilus influenzae, and Haemophilus parainfluenzae. For 261 pneumococci, XRP 2868 and pristinamycin MICs were similar, irrespective of penicillin G and erythromycin A susceptibilities (MIC at which 50% of isolates were inhibited [MIC50], 0.25 μg/ml; MIC90, 0.5 μg/ml), while quinupristin/dalfopristin had MICs which were 1 to 2 dilutions higher. Single components of both XRP 2868 and quinupristin/dalfopristin had higher MICs. Erythromycin A, azithromycin, clarithromycin, and clindamycin MICs were higher for penicillin G-intermediate and -resistant than -susceptible pneumococci. Against 150 H. influenzae strains, all compounds tested had unimodal MIC distributions. XRP 2868 had an overall MIC50 of 0.25 μg/ml and an MIC90 of 1.0 μg/ml, with no differences between β-lactamase-positive, β-lactamase-negative, and β-lactamase-negative ampicillin-resistant strains. Of note was the similarly low activity of one of its components, RPR 132552A. Pristinamycin and quinupristin/dalfopristin had MICs of 0.125 to 8.0 μg/ml; quinupristin alone had MICs of 8.0 to >64.0 μg/ml, and dalfopristin had MICs of 1.0 to >64.0 μg/ml. Erythromycin A, azithromycin, and clarithromycin had modal MICs of 4.0, 1.0, and 8.0 μg/ml, respectively. MICs of all compounds against H. parainfluenzae were 1 to 2 dilutions higher than against H. influenzae. XRP 2868 showed potent activity against pneumococci and Haemophilus strains irrespective of their susceptibility to other agents. PMID:14506040

  19. Histophilus somni causes extracellular trap formation by bovine neutrophils and macrophages.

    PubMed

    Hellenbrand, Katrina M; Forsythe, Katelyn M; Rivera-Rivas, Jose J; Czuprynski, Charles J; Aulik, Nicole A

    2013-01-01

    Histophilus somni (formerly Haemophilus somnus) is a Gram-negative pleomorphic coccobacillus that causes respiratory, reproductive, cardiac and neuronal diseases in cattle. H. somni is a member of the bovine respiratory disease complex that causes severe bronchopneumonia in cattle. Previously, it has been reported that bovine neutrophils and macrophages have limited ability to phagocytose and kill H. somni. Recently, it was discovered that bovine neutrophils and macrophages produce extracellular traps in response to Mannheimia haemolytica, another member of the bovine respiratory disease complex. In this study, we demonstrate that H. somni also causes extracellular trap production by bovine neutrophils in a dose- and time-dependent manner, which did not coincide with the release of lactate dehydrogenase, a marker for necrosis. Neutrophil extracellular traps were produced in response to outer membrane vesicles, but not lipooligosacchride alone. Using scanning electron microscopy and confocal microscopy, we observed H. somni cells trapped within a web-like structure. Further analyses demonstrated that bovine neutrophils trapped and killed H. somni in a DNA-dependent manner. Treatment of DNA extracellular traps with DNase I freed H. somni cells and diminished bacterial death. Treatment of bovine monocyte-derived macrophages with H. somni cells also caused macrophage extracellular trap formation. These findings suggest that extracellular traps may play a role in the host response to H. somni infection in cattle. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. [Haemophilus meningitis in properly vaccinated children: report of three cases].

    PubMed

    Metreau, Z; Le Bars, H; Desgranges-Federico, M; Monnier, M; Ryckewaert, A; Chasle, V; Pierre, M; Farges, C; Guitteny, M-A

    2013-05-01

    The 1993 introduction in France of the vaccine against the serotype b of Haemophilus influenzae (Hib) resulted in a fast reduction of invasive infections caused by this species. However, despite the introduction of a booster dose, cases of Hib meningitis can still be observed, even if they are exceptional. We report here on 3 cases of Hib meningitis observed at Rennes University Hospital, which occurred during the winter seasons between 2007 and 2010, in properly vaccinated infants and children aged 9, 14, and 29 months. Progression after treatment was satisfactory in all 3 cases, and no immune deficiency was detected. After 18 years of the vaccination policy in France, these observations demonstrate that a risk, although much lower, of Hib meningitis persists in infants and children, including in vaccinated patients, and that strains still are circulating within the general population. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Haemophilus parasuis serovars isolated from pathological samples in Northern Italy.

    PubMed

    Luppi, A; Bonilauri, P; Dottori, M; Iodice, G; Gherpelli, Y; Merialdi, G; Maioli, G; Martelli, P

    2013-04-01

    From January 2007 to December 2011, a total of 106 Haemophilus parasuis strains isolated from pigs were serotyped by agar gel diffusion test (DG). Serovar 4 was the most prevalent (24.5%), followed by serovar 13 (19.8%) and serovar 5 (11.3%). Twenty-nine strains were non-typeable (27.3%). The strains were divided into two groups, depending on whether they were isolated from specific pathological lesions of systemic disease such as polyserositis, arthritis or meningitis (73 cases of 106) or from the lower respiratory tract of pigs suffering from bronchopneumonia (33 cases of 106). Serovars 4 and 13 had a higher prevalence in systemic infection (polyserositis) than in respiratory disease only. Pasteurella multocida (14/106), Streptococcus suis (7/106), Actinobacillus pleuropneumoniae (4/106), Bordetella bronchiseptica (3/106) and Arcanobacterium pyogenes (3/106) were isolated in association with H. parasuis. © 2012 Blackwell Verlag GmbH.

  2. Haemophilus influenzae Type b Meningitis in the Short Period after Vaccination: A Reminder of the Phenomenon of Apparent Vaccine Failure.

    PubMed

    Greenberg-Kushnir, Noa; Haskin, Orly; Yarden-Bilavsky, Havatzelet; Amir, Jacob; Bilavsky, Efraim

    2012-01-01

    We present two cases of bacterial meningitis caused by Haemophilus influenzae type b (Hib) which developed a few days after conjugate Hib vaccination. This phenomenon of postimmunization provocative time period is reviewed and discussed. These cases serve as a reminder to clinicians of the risk, albeit rare, of invasive Hib disease in the short period after successful immunization.

  3. Epidemiology, clinical features, diagnosis and treatment of Haemophilus ducreyi - a disappearing pathogen?

    PubMed

    Lewis, David A

    2014-06-01

    Chancroid, caused by Haemophilus ducreyi, has declined in importance as a sexually transmitted pathogen in most countries where it was previously endemic. The global prevalence of chancroid is unknown as most countries lack the required laboratory diagnostic capacity and surveillance systems to determine this. H. ducreyi has recently emerged as a cause of chronic skin ulceration in some South Pacific islands. Although no antimicrobial susceptibility data for H. ducreyi have been published for two decades, it is still assumed that the infection will respond successfully to treatment with recommended cephalosporin, macrolide or fluoroquinolone-based regimens. HIV-1-infected patients require careful follow-up due to reports of treatment failure with single dose regimens. Buboes may need additional treatment with either aspiration or excision and drainage.

  4. Synthesis of Deoxyribonucleic Acid After Ultraviolet Irradiation of Sensitive and Resistant Haemophilus influenzae

    PubMed Central

    Modak, Sohan P.; Setlow, Jane K.

    1969-01-01

    Synthesis of deoxyribonucleic acid (DNA) has been measured as a function of ultraviolet (UV) radiation dose in wild-type and seven UV-sensitive strains of Haemophilus influenzae. At the UV doses used, all strains were able to resume DNA synthesis, even those which are unable to excise pyrimidine dimers from their DNA. These excisionless strains showed longer UV-induced delays in DNA synthesis than all but one of the other strains. The longest delay was shown by DB117, a strain which can excise dimers but which is recombination deficient and unable to rejoin X ray-induced single-strand breaks. All strains showed a progressive decrease in sensitivity as they approached the stationary phase. PMID:5305934

  5. Haemophilus influenzae Type b Meningitis in the Short Period after Vaccination: A Reminder of the Phenomenon of Apparent Vaccine Failure

    PubMed Central

    Greenberg-Kushnir, Noa; Haskin, Orly; Yarden-Bilavsky, Havatzelet; Amir, Jacob; Bilavsky, Efraim

    2012-01-01

    We present two cases of bacterial meningitis caused by Haemophilus influenzae type b (Hib) which developed a few days after conjugate Hib vaccination. This phenomenon of postimmunization provocative time period is reviewed and discussed. These cases serve as a reminder to clinicians of the risk, albeit rare, of invasive Hib disease in the short period after successful immunization. PMID:22953084

  6. Molecular characterization of phosphorylcholine expression on the lipooligosaccharide of Histophilus somni.

    PubMed

    Elswaifi, Shaadi F; St Michael, Frank; Sreenivas, Avula; Cox, Andrew; Carman, George M; Inzana, Thomas J

    2009-10-01

    Histophilus somni (Haemophilus somnus) is an important pathogen of cattle that is responsible for respiratory disease, septicemia, and systemic diseases such as thrombotic meningoencephalitis, myocarditis, and abortion. A variety of virulence factors have been identified in H. somni, including compositional and antigenic variation of the lipooligosaccharide (LOS). Phosphorylcholine (ChoP) has been identified as one of the components of H. somni LOS that undergoes antigenic variation. In this study, five genes (lic1ABCD(Hs) and glpQ) with homology to genes responsible for ChoP expression in Haemophilus influenzae LOS were identified in the H. somni genome. An H. somni open reading frame (ORF) with homology to H. influenzae lic1A (lic1A(Hi)) contained a variable number of tandem repeats (VNTR). However, whereas the tetranucleotide repeat 5'-CAAT-3' is present in lic1A(Hi), the VNTR in H. somni lic1A (lic1A(Hs)) consisted of 5'-AACC-3'. Due to the propensity of VNTR to vary during replication and cause the ORF to shift in and out of frame with the upstream start codon, the VNTR were deleted from lic1A(Hs) to maintain the gene constitutively on. This construct was cloned into Escherichia coli, and functional enzyme assays confirmed that lic1A(Hs) encoded a choline kinase, and that the VNTR were not required for expression of a functional gene product. Variation in the number of VNTR in lic1A(Hs) correlated with antigenic variation of ChoP expression in H. somni strain 124P. However, antigenic variation of ChoP expression in strain 738 predominately occurred through variable extension/truncation of the LOS outer core. These results indicated that the lic1(Hs) genes controlled expression of ChoP on the LOS, but that in H. somni there are two potential mechanisms that account for antigenic variation of ChoP.

  7. Molecular characterization of phosphorylcholine expression on the lipooligosaccharide of Histophilus somni

    PubMed Central

    Elswaifi, Shaadi F.; St. Michael, Frank; Sreenivas, Avula; Cox, Andrew; Carman, George M.; Inzana, Thomas J.

    2013-01-01

    Histophilus somni (Haemophilus somnus) is an important pathogen of cattle that is responsible for respiratory disease, septicemia, and systemic diseases such as thrombotic meningoencephalitis, myocarditis, and abortion. A variety of virulence factors have been identified in H. somni, including compositional and antigenic variation of the lipooligosaccharide (LOS). Phosphorylcholine (ChoP) has been identified as one of the components of H. somni LOS that undergoes antigenic variation. In this study, five genes (lic1ABCDHs and glpQ) with homology to genes responsible for ChoP expression in Haemophilus influenzae LOS were identified in the H. somni genome. An H. somni open reading frame (ORF) with homology to H. influenzae lic1A (lic1AHi) contained a variable number of tandem repeats (VNTR). However, whereas the tetranucleotide repeat 5′-CAAT-3′ is present in lic1AHi, the VNTR in H. somni lic1A (lic1AHs) consisted of 5′-AACC-3′. Due to the propensity of VNTR to vary during replication and cause the ORF to shift in and out of frame with the upstream start codon, the VNTR were deleted from lic1AHs to maintain the gene constitutively on. This construct was cloned into Escherichia coli, and functional enzyme assays confirmed that lic1AHs encoded a choline kinase, and that the VNTR were not required for expression of a functional gene product. Variation in the number of VNTR in lic1AHs correlated with antigenic variation of ChoP expression in H. somni strain 124P. However, antigenic variation of ChoP expression in strain 738 predominately occurred through variable extension/truncation of the LOS outer core. These results indicated that the lic1Hs genes controlled expression of ChoP on the LOS, but that in H. somni there are two potential mechanisms that account for antigenic variation of ChoP. PMID:19682567

  8. The cytolethal distending toxin of Haemophilus ducreyi aggravates dermal lesions in a rabbit model of chancroid.

    PubMed

    Wising, Catharina; Mölne, Lena; Jonsson, Ing-Marie; Ahlman, Karin; Lagergård, Teresa

    2005-05-01

    Haemophilus ducreyi, the etiologic agent of the sexually transmitted disease chancroid, produces a cytolethal distending toxin (HdCDT) that inhibits cultured cell proliferation, leading to cell death. A rabbit model of dermal infection was used to investigate the roles of H. ducreyi bacteria and HdCDT in the development, clinical appearance, and persistence of infection. A non-toxin producing H. ducreyi strain, and for comparison purposes a non-capsulated Haemophilus influenzae strain, were inoculated intradermally, with and without co-administration of purified HdCDT. Co-administration of HdCDT resulted in significant aggravation of H. ducreyi-induced inflammatory lesions, and development of ulcers in rabbit skin. Less pronounced inflammatory lesions and lack of epithelial eruption were observed after inoculation with H. influenzae. Histopathological sections of the H. ducreyi-induced lesions, in both the presence and absence of HdCDT, showed dense infiltrates of the same type inflammatory cells, with the exception of a prominent endothelial cell proliferation noted in sections from lesions caused by H. ducreyi and toxin. Signs of chronic inflammation with involvement of T cells, macrophages, eosinophils, and granuloma formation were observed after H. ducreyi inoculation both with and without toxin. In conclusion, H. ducreyi causes a pronounced, chronic inflammation with involvement of T cells and macrophages, and in combination with HdCDT production of ulcers in the rabbit model. These pathogenic mechanisms may promote the development and persistence of chancroid ulcers.

  9. In Vitro Activity of Delafloxacin Tested against Isolates of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis

    PubMed Central

    Rhomberg, Paul R.; Huband, Michael D.; Farrell, David J.

    2016-01-01

    Delafloxacin, an investigational anionic fluoroquinolone, is active against a broad range of Gram-positive and Gram-negative bacteria. In this study, 200 Streptococcus pneumoniae (plus 30 levofloxacin-resistant isolates), 200 Haemophilus influenzae, and 100 Moraxella catarrhalis isolates selected primarily from the United States (2014) were tested against delafloxacin and comparator agents. Delafloxacin was the most potent agent tested. MIC50 and MIC90 values against all S. pneumoniae isolates were 0.008 and 0.015 μg/ml. Delafloxacin susceptibility was not affected by β-lactamase status against H. influenzae and M. catarrhalis. PMID:27458220

  10. Intervertebral discitis caused by nontypeable Haemophilus influenzae in an adult: Case report.

    PubMed

    Boulton, R; Swayamprakasam, A; Raza, M

    2012-01-01

    Haemophilus influenzae is a common cause of bacterial meningitis in children and can cause upper respiratory tract infections in adults, but has yet to be reported solely involving intervertebral discitis. A 67-year-old builder presenting with fever, myalgia and back pain is found to have intervertebral discitis (confirmed on MRI) caused by H. influenzae (identified on blood cultures). A nontypeable form of H. influenzae has not been reported causing discitis. We describe a case in a relatively fit individual who was treated successfully with antimicrobial treatment. A preceding upper respiratory tract infection is the presumed source of infection, predisposed by long-term low-dose steroid therapy. H. influenzae is a rare, but treatable cause of discitis. Copyright © 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  11. Crystallization of recombinant Haemophilus influenzaee (P4) acid phosphatase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ou, Zhonghui; Felts, Richard L.; Reilly, Thomas J.

    2006-05-01

    Lipoprotein e (P4) is a class C acid phosphatase and a potential vaccine candidate for nontypeable H. influenzae infections. This paper reports the crystallization of recombinant e (P4) and the acquisition of a 1.7 Å resolution native X-ray diffraction data set. Haemophilus influenzae infects the upper respiratory tract of humans and can cause infections of the middle ear, sinuses and bronchi. The virulence of the pathogen is thought to involve a group of surface-localized macromolecular components that mediate interactions at the host–pathogen interface. One of these components is lipoprotein e (P4), which is a class C acid phosphatase and amore » potential vaccine candidate for nontypeable H. influenzae infections. This paper reports the crystallization of recombinant e (P4) and the acquisition of a 1.7 Å resolution native X-ray diffraction data set. The space group is P4{sub 2}2{sub 1}2, with unit-cell parameters a = 65.6, c = 101.4 Å, one protein molecule per asymmetric unit and 37% solvent content. This is the first report of the crystallization of a class C acid phosphatase.« less

  12. Localization of Haemophilus ducreyi in naturally acquired chancroidal ulcers.

    PubMed

    Bauer, Margaret E; Townsend, Carisa A; Ronald, Allan R; Spinola, Stanley M

    2006-08-01

    Haemophilus ducreyi causes the sexually transmitted genital ulcer disease chancroid. In human inoculation experiments, bacteria colocalize with neutrophils and macrophages but remain extracellular. The organism also colocalizes with collagen and fibrin but not with keratinocytes, fibroblasts, laminin, or fibronectin. These relationships are established by 48 h postinoculation and persist through the pustular stage of disease. To extend these observations to the ulcerative stage of disease, and to compare results in the human model with those of natural disease, we obtained biopsies from patients with naturally acquired chancroid. All ulcers were culture positive for H. ducreyi and histologically very similar to pustules from the human model. Staining with H. ducreyi-specific monoclonal antibodies demonstrated H. ducreyi within 5 biopsies. The organism was chiefly found within the granulocytic infiltrate of the ulcer. Dual staining for H. ducreyi and eukaryotic tissue components showed that H. ducreyi colocalized with neutrophils and fibrin at the ulcerative stage of disease. No bacteria were associated with keratinocytes, fibroblasts, or collagen. Overall, these findings are consistent with results from the human model. This is the first reported study to localize bacteria specifically identified as H. ducreyi within naturally acquired chancroid.

  13. β-Lactam Resistance in Haemophilus parasuis Is Mediated by Plasmid pB1000 Bearing blaROB-1▿

    PubMed Central

    San Millan, Alvaro; Escudero, Jose Antonio; Catalan, Ana; Nieto, Silvia; Farelo, Fidel; Gibert, Magdalena; Moreno, Miguel Angel; Dominguez, Lucas; Gonzalez-Zorn, Bruno

    2007-01-01

    β-Lactam resistance in Haemophilus parasuis is an emerging phenomenon that has not yet been characterized from a molecular perspective. Clinical high-level β-lactam-resistant isolates from Spain bore a novel plasmid, pB1000, expressing a functionally active ROB-1 β-lactamase. Pulsed-field gel electrophoresis was applied for the first time to H. parasuis and showed that β-lactam resistance is due to clonal spread of a resistant strain, BB1018, bearing pB1000. PMID:17438055

  14. Haemophilus is overrepresented in the nasopharynx of infants hospitalized with RSV infection and associated with increased viral load and enhanced mucosal CXCL8 responses.

    PubMed

    Ederveen, Thomas H A; Ferwerda, Gerben; Ahout, Inge M; Vissers, Marloes; de Groot, Ronald; Boekhorst, Jos; Timmerman, Harro M; Huynen, Martijn A; van Hijum, Sacha A F T; de Jonge, Marien I

    2018-01-11

    While almost all infants are infected with respiratory syncytial virus (RSV) before the age of 2 years, only a small percentage develops severe disease. Previous studies suggest that the nasopharyngeal microbiome affects disease development. We therefore studied the effect of the nasopharyngeal microbiome on viral load and mucosal cytokine responses, two important factors influencing the pathophysiology of RSV disease. To determine the relation between (i) the microbiome of the upper respiratory tract, (ii) viral load, and (iii) host mucosal inflammation during an RSV infection, nasopharyngeal microbiota profiles of RSV infected infants (< 6 months) with different levels of disease severity and age-matched healthy controls were determined by 16S rRNA marker gene sequencing. The viral load was measured using qPCR. Nasopharyngeal CCL5, CXCL10, MMP9, IL6, and CXCL8 levels were determined with ELISA. Viral load in nasopharyngeal aspirates of patients associates significantly to total nasopharyngeal microbiota composition. Healthy infants (n = 21) and RSV patients (n = 54) display very distinct microbial patterns, primarily characterized by a loss in commensals like Veillonella and overrepresentation of opportunistic organisms like Haemophilus and Achromobacter in RSV-infected individuals. Furthermore, nasopharyngeal microbiota profiles are significantly different based on CXCL8 levels. CXCL8 is a chemokine that was previously found to be indicative for disease severity and for which we find Haemophilus abundance as the strongest predictor for CXCL8 levels. The nasopharyngeal microbiota in young infants with RSV infection is marked by an overrepresentation of the genus Haemophilus. We present that this bacterium is associated with viral load and mucosal CXCL8 responses, both which are involved in RSV disease pathogenesis.

  15. In Vitro Activity of Delafloxacin Tested against Isolates of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

    PubMed

    Flamm, Robert K; Rhomberg, Paul R; Huband, Michael D; Farrell, David J

    2016-10-01

    Delafloxacin, an investigational anionic fluoroquinolone, is active against a broad range of Gram-positive and Gram-negative bacteria. In this study, 200 Streptococcus pneumoniae (plus 30 levofloxacin-resistant isolates), 200 Haemophilus influenzae, and 100 Moraxella catarrhalis isolates selected primarily from the United States (2014) were tested against delafloxacin and comparator agents. Delafloxacin was the most potent agent tested. MIC50 and MIC90 values against all S. pneumoniae isolates were 0.008 and 0.015 μg/ml. Delafloxacin susceptibility was not affected by β-lactamase status against H. influenzae and M. catarrhalis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  16. Haemophilus influenzae serotype a invasive disease, Alaska, USA, 1983-2011.

    PubMed

    Bruce, Michael G; Zulz, Tammy; DeByle, Carolynn; Singleton, Ros; Hurlburt, Debby; Bruden, Dana; Rudolph, Karen; Hennessy, Thomas; Klejka, Joseph; Wenger, Jay D

    2013-06-01

    Before introduction of Haemophilus influenzae type b (Hib) vaccines, rates of Hib disease in Alaska's indigenous people were among the highest in the world. Vaccination reduced rates dramatically; however, invasive H. influenzae type a (Hia) disease has emerged. Cases of invasive disease were identified through Alaska statewide surveillance during 1983-2011. Of 866 isolates analyzed for serotype, 32 (4%) were Hia. No Hia disease was identified before 2002; 32 cases occurred during 2002-2011 (p<0.001). Median age of case-patients was 0.7 years; 3 infants died. Incidence of Hia infection (2002-2011) among children <5 years was 5.4/100,000; 27 cases occurred in Alaska Native children (18/100,000) versus 2 cases in non-Native children (0.5/100,000) (risk ratio = 36, p<0.001). From 12/2009 to 12/2011, 15 cases of Hia disease occurred in southwestern Alaska (in children <5 years, rate = 204/100,000). Since introduction of the Hib conjugate vaccine, Hia infection has become a major invasive bacterial disease in Alaska Native children.

  17. Epidemiology of Invasive Haemophilus influenzae Disease, Europe, 2007–2014

    PubMed Central

    Economopoulou, Assimoula; Dias, Joana Gomes; Bancroft, Elizabeth; Ramliden, Miriam; Celentano, Lucia Pastore

    2017-01-01

    We describe the epidemiology of invasive Haemophilus influenzae disease during 2007–2014 in 12 European countries and assess overall H. influenzae disease trends by serotype and patient age. Mean annual notification rate was 0.6 cases/100,000 population, with an increasing annual trend of 3.3% (95% CI 2.3% to 4.3%). The notification rate was highest for patients <1 month of age (23.4 cases/100,000 population). Nontypeable H. influenzae (NTHi) caused 78% of all cases and showed increasing trends among persons <1 month and >20 years of age. Serotype f cases showed an increasing trend among persons >60 years of age. Serotype b cases showed decreasing trends among persons 1–5 months, 1–4 years, and >40 years of age. Sustained success of routine H. influenzae serotype b vaccination is evident. Surveillance systems must adopt a broad focus for invasive H. influenzae disease. Increasing reports of NTHi, particularly among neonates, highlight the potential benefit of a vaccine against NTHi. PMID:28220749

  18. Haemophilus influenzae serotype a as a cause of serious invasive infections.

    PubMed

    Ulanova, Marina; Tsang, Raymond S W

    2014-01-01

    Haemophilus influenzae, particularly H influenzae serotype b (Hib), is an important pathogen that causes serious diseases like meningitis and septicaemia. Since the introduction of Hib conjugate vaccines in the 1990s, the epidemiology of invasive H influenzae disease has changed substantially, with most infections now caused by non-Hib strains. We discuss the importance of H influenzae serotype a (Hia) as a cause of serious morbidity and mortality and its global epidemiology, clinical presentation, microbiology, immunology, prevention, and control. Much like Hib, the capsule of Hia is an important virulence factor contributing to the development of invasive disease. Molecular typing of Hia has identified distinct clonal groups, with some linked to severe disease and high case-fatality rates. Similarities between Hia and Hib capsules, their clinical presentation, and immunology of infection suggest that a bivalent Hia-Hib capsular polysaccharide-protein conjugate vaccine could offer protection against these two important serotypes of H influenzae. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Invasive Disease Due to Nontypeable Haemophilus influenzae among Children in Arkansas

    PubMed Central

    O'Neill, Joshua M.; St. Geme III, Joseph W.; Cutter, David; Adderson, Elisabeth E.; Anyanwu, Juliana; Jacobs, Richard F.; Schutze, Gordon E.

    2003-01-01

    In this study, we reviewed cases of invasive disease due to nontypeable Haemophilus influenzae among children hospitalized at Arkansas Children's Hospital from 1993 to 2001. A total of 28 cases were examined, including 21 associated with bacteremia and 4 associated with meningitis. Of the patients examined, 86% were ≤4 years of age, and 68% had underlying medical conditions. Characterization of the bacterial isolates by multilocus sequence type genotyping revealed significant overall genetic diversity, similar to the diversity in the general population structure for nontypeable H. influenzae. However, four separate pairs of isolates were closely related genetically, a relationship confirmed by pulsed-field gel electrophoresis and Southern hybridization studies using probes for the major H. influenzae adhesin genes. These results suggest that selected strains of nontypeable H. influenzae may have more invasive potential, especially in young children and patients with underlying medical conditions. At this point, the specific factors that contribute to enhanced virulence remain unclear. PMID:12843045

  20. Detection of a Bacteriophage Gene Encoding a Mu-like Portal Protein in Haemophilus parasuis Reference Strains and Field Isolates by Nested Polymerase Chain Reaction

    USDA-ARS?s Scientific Manuscript database

    A nested PCR assay was developed to determine the presence of a gene encoding a bacteriophage Mu-like portal protein, gp29, in 15 reference strains and 31 field isolates of Haemophilus parasuis. Specific primers, based on the gene’s sequence, were utilized. A majority of the virulent reference strai...

  1. American Academy of Dental Sleep Medicine

    MedlinePlus

    ... Coverage New Research AADSM Highlights Members More news... Dental Sleep Medicine: An area of dental practice that focuses on the use of oral ... News RSS Links Find A Dentist Platinum Sponsors Dental Sleep Solutions Nierman Practice Management ProSomnus Sleep Technologies ...

  2. An application of outer membrane protein p6-specific enzyme-linked immunosorbent assay for detection of haemophilus influenzae in middle ear fluids and nasopharyngeal secretions.

    PubMed

    Hotomi, Muneki; Togawa, Akihisa; Kono, Masamitsu; Sugita, Gen; Sugita, Rinya; Fujimaki, Yutaka; Kamide, Yosuke; Uchizono, Akihiro; Kanesada, Keiko; Sawada, Shoichi; Okitsu, Naohiro; Masuda, Hisayo; Tanaka, Hideaki; Tanaka, Yumi; Yamanaka, Noboru

    2013-01-01

    An enzyme-linked immunosorbent assay specific to outer membrane protein P6 (P6-ELISA) was applied for detecting Haemophilus influenzae in middle ear fluids (MEFs) from acute otitis media (AOM) patients and in nasopharyngeal secretions (NPSs) from acute rhinosinusitis patients. P6-ELISA had a sensitivity of 83.3% for MEFs and 71.5% for NPSs and a specificity of 85.6% for MEFs and 92.5% for NPSs, respectively. Real-time PCR exhibited significant differences in the number of ompP1 gene copies among samples determined by P6-ELISA to be positive and negative for H. influenzae. However, because the P6-ELISA test has the reactivity in Haemophilus species include two commensals H. haemolyticus and H. parainfluenzae, it is thus a weak method in order to detect only NTHi correctly. Consequently, diagnosis using the P6-ELISA should be based on an overall evaluation, including the results of other related examinations and clinical symptoms to prevent misleading conclusions in clinical setting.

  3. Haemophilus influenzae type b conjugate vaccine impact against purulent meningitis in Rwanda.

    PubMed

    Muganga, Narcisse; Uwimana, Jeannine; Fidele, Ngabo; Gahimbare, Laetitia; Gessner, Bradford D; Mueller, Judith E; Mhlanga, Bekithemba R; Katsande, Reggis; Herbinger, Karl-Heinz; Rugambwa, Celse

    2007-09-28

    Rwanda introduced Haemophilus influenzae type b (Hib) conjugate vaccine in January 2002 and simultaneously implemented pediatric bacterial meningitis surveillance at a major referral hospital in the capital Kigali. We reviewed clinical and laboratory information collected during January 2002 to June 2006. Due to a variety of laboratory limitations, only eight confirmed Hib cases were identified, all before 2004. However, the proportion of cerebrospinal fluid with purulence decreased from 26.0% during 2002, to 15.9% during 2003, 9.7% during 2004 and 8.4% in 2005 (p<0.001). Vaccine effectiveness of two or three doses of Hib vaccine against purulent meningitis was 52% (95% confidence interval, 5-75%). In an African setting with few resources and in which few confirmed Hib meningitis cases were identified, Hib vaccine impact nevertheless could be demonstrated against the outcome of purulent meningitis and was found to be high.

  4. A comparison of a new oral streptogramin XRP 2868 with quinupristin-dalfopristin against antibiotic-resistant strains of haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae.

    PubMed

    Mabe, Susan; Champney, W Scott

    2005-12-01

    A new streptogramin antibiotic XRP 2868 was compared with quinupristin-dalfopristin for inhibitory activities against antibiotic-resistant Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae. In each organism examined, XRP 2868 had an IC(50) that was twofold to fivefold lower than quinupristin-dalfopristin, for inhibition of cell viability, protein synthesis, and ribosomal subunit formation.

  5. Real-time polymerase chain reaction for detection of encapsulated Haemophilus influenzae using degenerate primers to target the capsule transport gene bexA.

    PubMed

    Law, Dennis K S; Tsang, Raymond S W

    2013-05-01

    A real-time polymerase chain reaction assay that uses degenerate primers and a dual-labelled probe was developed to detect the bexA gene of Haemophilus influenzae, including those belonging to non-b serotypes as well as clonal division II strains. This assay is sensitive and specific, detecting 20 copies of the gene, but negative with a variety of bacteria associated with meningitis and bacteremia or septicemia.

  6. Meningitis and septicemia caused by nontypeable Haemophilus influenzae in a previously healthy 2-year-old girl.

    PubMed

    Ito, Takao; Shibata, Hironori; Nakazawa, Mie; Myokai, Michiko; Ikegaya, Kazuko; Tsuchiya, Ken; Kamimaki, Tsutomu

    2011-08-01

    Nontypeable Haemophilus influenzae (NTHi) commonly colonizes the upper respiratory tract of children and causes otitis media, sinusitis, and bronchitis. Invasive NTHi diseases such as meningitis and septicemia have rarely been reported, especially in children with underlying predisposing conditions such as head trauma and immune compromise. However, we report a previously healthy 2-year-old girl who developed meningitis and septicemia caused by NTHi biotype ΙΙΙ. She was treated with dexamethasone, meropenem, and ceftriaxone, and recovered uneventfully. We wish to emphasize that NTHi should be borne in mind as a potential pathogen that can cause meningitis and septicemia, even in previously healthy children.

  7. Effect of Pneumococcal Vaccination on Nasopharyngeal Carriage of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus in Fijian Children

    PubMed Central

    Manning, Jayne; Russell, Fiona M.; Robins-Browne, Roy M.; Mulholland, E. Kim; Satzke, Catherine

    2012-01-01

    The 7-valent pneumococcal conjugate vaccine (PCV7) reduces carriage of vaccine type Streptococcus pneumoniae but leads to replacement by nonvaccine serotypes and may affect carriage of other respiratory pathogens. We investigated nasopharyngeal carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus in Fijian infants participating in a pneumococcal vaccine trial using quantitative PCR. Vaccination did not affect pathogen carriage rates or densities, whereas significant differences between the two major ethnic groups were observed. PMID:22170924

  8. Rapid Assessment Tool for Haemophilus influenzae type b Disease in Developing Countries1

    PubMed Central

    Nelson, Christopher B.; Watt, James P.; Mohsni, Ezzeddine; Wenger, Jay D.; Levine, Orin S.

    2004-01-01

    Haemophilus influenzae type b (Hib) still causes a substantial number of deaths among children in developing countries, despite the availability of effective conjugate vaccines. A major obstacle in developing a Hib vaccine has been limited awareness about the impact of Hib disease. A tool was developed to estimate the national rates of Hib meningitis and pneumonia by assessing retrospective local data over 7 to 10 days. Data from 11 countries in Africa, the Middle East, and Asia were studied and showed rates of Hib meningitis from >50 cases per 100,000 children >5 years in Ghana and Uganda to <15 per 100,000 in Iran, Jordan, and Uzbekistan. Results were affected by the quality of available data. The Hib rapid assessment tool can be useful to countries that desire a timely assessment of Hib disease rates. PMID:15324548

  9. Biochemical, genetic, and epidemiologic characterization of Haemophilus influenzae biogroup aegyptius (Haemophilus aegyptius) strains associated with Brazilian purpuric fever.

    PubMed Central

    Brenner, D J; Mayer, L W; Carlone, G M; Harrison, L H; Bibb, W F; Brandileone, M C; Sottnek, F O; Irino, K; Reeves, M W; Swenson, J M

    1988-01-01

    Brazilian purpuric fever (BPF) is a recently recognized fulminant pediatric disease characterized by fever, with rapid progression to purpura, hypotensive shock, and death. BPF is usually preceded by purulent conjunctivitis that has resolved before the onset of fever. Both the conjunctivitis and BPF are caused by Haemophilus influenzae biogroup aegyptius (formerly called H. aegyptius). Isolates from 15 BPF cases, mainly from blood or hemorrhagic cerebrospinal fluid, case-associated isolates from 42 persons in towns where BPF cases occurred, and control strains from 32 persons in towns without BPF cases were characterized biochemically, genetically, and epidemiologically. Results indicated that a single clone was responsible for all BPF cases identified in six Brazilian towns from 1984 through 1986. All of 15 (100%) case strains were the same clone as was 1 of 32 (3%) control strains (P = less than 10(-8). Isolates of the clone were preferentially intrarelated by DNA hybridization (99% relatedness, hydroxyapatite method at 60 and 75 degrees C) and were separable from other H. influenzae biogroup aegyptius strains (approximately 90% relatedness at 60 degrees C and 82% relatedness at 75 degrees C). All isolates of the BPF clone and no other strains contained a 24-megadalton plasmid of restriction endonuclease type 3031, were of a single multilocus enzyme mobility type, were of a single sodium dodecyl sulfate-polyacrylamide gel electrophoresis type, and were in one of two ribosomal DNA restriction patterns. All BPF clone isolates reacted with monoclonal antibodies produced from a case strain; only 3 of 62 (5%) other strains reacted with this monoclonal antibody. Ninety percent of BPF clone strains and 27% of other strains were relatively resistant to sulfamethoxazole-trimethoprim. Images PMID:3262623

  10. Incidence of Haemophilus influenzae type b disease in The Gambia 14 years after introduction of routine Haemophilus influenzae type b conjugate vaccine immunization.

    PubMed

    Oluwalana, Claire; Howie, Stephen R C; Secka, Ousman; Ideh, Readon C; Ebruke, Bernard; Sambou, Sana; Erskine, James; Lowe, Yamundow; Corrah, Tumani; Adegbola, Richard A

    2013-07-01

    Haemophilus influenzae type b (Hib) conjugate vaccine was first introduced in Africa in The Gambia in 1997 as a primary 3-dose course in infancy with no booster, and was followed by the disappearance of invasive Hib disease by 2002. A cluster of cases detected non-systematically in post-infant children in 2005-2006 raised the question of the need for a booster dose. The objective of this study was to determine the incidence of invasive Hib disease in Gambian children 14 years after the introduction of Hib conjugate vaccine. This hospital-based clinical and microbiological Hib disease surveillance in 3 hospitals in the western region of The Gambia was undertaken between October 2007 and December 2010 applying the same methods used in a previous Hib vaccine effectiveness study in 1997-2002. The annual incidences of Hib meningitis and all invasive Hib disease in children aged <5 years remained below 5 cases per 100,000 children during 2008-2010. The median age of patients with any invasive Hib disease was 5 months. Hib conjugate vaccination as a primary 3-dose course in The Gambia remains highly effective in controlling invasive Hib disease, and current data do not support the introduction of a booster dose. Copyright © 2013. Published by Mosby, Inc.

  11. Assessing the antibiotic potential of essential oils against Haemophilus ducreyi.

    PubMed

    Lindeman, Zachary; Waggoner, Molly; Batdorff, Audra; Humphreys, Tricia L

    2014-05-27

    Haemophilus ducreyi is the bacterium responsible for the genital ulcer disease chancroid, a cofactor for the transmission of HIV, and it is resistant to many antibiotics. With the goal of exploring possible alternative treatments, we tested essential oils (EOs) for their efficacy as antimicrobial agents against H. ducreyi. We determine the minimum inhibitory concentration (MIC) of Cinnamomum verum (cinnamon), Eugenia caryophyllus (clove) and Thymus satureioides (thyme) oil against 9 strains of H. ducreyi using the agar dilution method. We also determined the minimum lethal concentration for each oil by subculturing from the MIC plates onto fresh agar without essential oil. For both tests, we used a 2-way ANOVA to evaluate whether antibiotic-resistant strains had a different sensitivity to the oils relative to non-resistant strains. All 3 oils demonstrated excellent activity against H. ducreyi, with MICs of 0.05 to 0.52 mg/mL and MLCs of 0.1-0.5 mg/mL. Antibiotic-resistant strains of H. ducreyi were equally susceptible to these 3 essential oils relative to non-resistant strains (p=0.409). E. caryophyllus, C. verum and T. satureioides oils are promising alternatives to antibiotic treatment for chancroid.

  12. Haemophilus ducreyi: from sexually transmitted infection to skin ulcer pathogen.

    PubMed

    Lewis, David A; Mitjà, Oriol

    2016-02-01

    This article provides an overview of the biology, epidemiology, clinical features, diagnostic tests, and treatment of Haemophilus ducreyi infection, with special reference to the decline of chancroid and the recent emergence of H. ducreyi as a pathogen responsible for chronic limb ulceration clinically similar to yaws. Chancroid has declined in importance as a sexually transmitted infection in most countries where it was previously endemic. Chancroid may be caused by either class I or class II H. ducreyi isolates; these two classes diverged from each other approximately 1.95 million years ago. H. ducreyi has recently emerged as a cause of chronic skin ulceration in the Pacific region and Africa. Based on sequencing of whole genomes and defined genetic loci, it appears that the cutaneous H. ducreyi strains diverged from the class I genital strains relatively recently. H. ducreyi should be considered as a major cause of chronic limb ulceration in both adults and children and appropriate molecular diagnostic assays are required to determine ulcer aetiology. The high prevalence of H. ducreyi-related cutaneous ulceration in yaws-endemic countries has challenged the validity of observational surveys to monitor the effectiveness of the WHO's yaws eradication campaign.

  13. [Mechanisms of beta-lactam and quinolone resistance in Haemophilus influenzae].

    PubMed

    Ubukata, Kimiko

    2012-02-01

    Haemophilus influenzae is one of the important pathogens causing respiratory tract infections, pneumonia, and meningitis. Genotypic(g) beta-lactamase-nonproducing ampicillin resistance (gBLNAR) H. influenzae has rapidly increased since 2000 years in Japan. The resistant percentage exceeded 60% in Hib isolates from meningitis in 2009. The affinity of beta-lactam antibiotics for penicillin-binding proteins-3 (PBP3) that involved in septal peptidoglycan synthesis deceased in the resistant strains. Three amino acid substitutions, Ser385Thr, Asn526Lys and Arg517His in PBP3 encoded by ftsI gene are especially responsible for beta-lactam resistance in the gBLNAR. Susceptibilities of cephalosporin agents including cefotaxime for gBLNAR were apparently decreased than the ampicillin and carbapenem antibiotics. Though fluoroquinolone resistant isolates are rare (< 1%) in H. influenzae, strains of levofloxacin and ciprofloxacin MIC with > or = 8 microg/mL were isolated from elderly patients with CAP. These strains possessed amino acid substitutions of Ser84Phe and Asp88Asn in GyrA and Glu88Lys in ParC. It is important to practice rapidly identification of these resistant strains at routine work.

  14. Deletion of HAPS_2096 Increases Sensitivity to Cecropin B in Haemophilus parasuis.

    PubMed

    Chen, Fanjie; Hu, Han; Li, Zhonghua; Huang, Jiacheng; Cai, Xuwang; Wang, Chunmei; He, Qigai; Cao, Jiyue

    2015-01-01

    Cecropin B (CB) is a very effective natural antimicrobial peptide that has shown great potential for future antimicrobial drug development. HAPS_2096 is a Haemophilus parasuis gene that encodes the periplasmic substrate-binding protein of an ATP-binding cassette-type amino acid transporter. In this research, we constructed and verified an HAPS_2096 deletion mutant and a complementary HAPS_2096 mutant of H. parasuis JS0135. A bactericidal assay revealed that the HAPS_2096 deletion mutant was significantly more sensitive than the wild-type strain to 0.25-0.5 µg/ml CB. However, the gene complementation alleviated the CB sensitivity of the mutant. Immunoelectron microscopy observation following a 30-min treatment with a sublethal concentration of CB (0.25 μg/ml) revealed more extensive morphological damage in the mutant strain than in the wild-type strain. Hence, our results suggest that the HAPS_2096 gene contributes to H. parasuis resistance to CB. © 2015 S. Karger AG, Basel.

  15. Modeling Insights into Haemophilus influenzae Type b Disease, Transmission, and Vaccine Programs

    PubMed Central

    Rose, Charles E.; Cohn, Amanda; Coronado, Fatima; Clark, Thomas A.; Wenger, Jay D.; Bulkow, Lisa; Bruce, Michael G.; Messonnier, Nancy E.; Hennessy, Thomas W.

    2012-01-01

    In response to the 2007–2009 Haemophilus influenzae type b (Hib) vaccine shortage in the United States, we developed a flexible model of Hib transmission and disease for optimizing Hib vaccine programs in diverse populations and situations. The model classifies population members by age, colonization/disease status, and antibody levels, with movement across categories defined by differential equations. We implemented the model for the United States as a whole, England and Wales, and the Alaska Native population. This model accurately simulated Hib incidence in all 3 populations, including the increased incidence in England/Wales beginning in 1999 and the change in Hib incidence in Alaska Natives after switching Hib vaccines in 1996. The model suggests that a vaccine shortage requiring deferral of the booster dose could last 3 years in the United States before loss of herd immunity would result in increasing rates of invasive Hib disease in children <5 years of age. PMID:22257582

  16. Modulation of Haemophilus influenzae interaction with hydrophobic molecules by the VacJ/MlaA lipoprotein impacts strongly on its interplay with the airways.

    PubMed

    Fernández-Calvet, Ariadna; Rodríguez-Arce, Irene; Almagro, Goizeder; Moleres, Javier; Euba, Begoña; Caballero, Lucía; Martí, Sara; Ramos-Vivas, José; Bartholomew, Toby Leigh; Morales, Xabier; Ortíz-de-Solórzano, Carlos; Yuste, José Enrique; Bengoechea, José Antonio; Conde-Álvarez, Raquel; Garmendia, Junkal

    2018-05-02

    Airway infection by nontypeable Haemophilus influenzae (NTHi) associates to chronic obstructive pulmonary disease (COPD) exacerbation and asthma neutrophilic airway inflammation. Lipids are key inflammatory mediators in these disease conditions and consequently, NTHi may encounter free fatty acids during airway persistence. However, molecular information on the interplay NTHi-free fatty acids is limited, and we lack evidence on the importance of such interaction to infection. Maintenance of the outer membrane lipid asymmetry may play an essential role in NTHi barrier function and interaction with hydrophobic molecules. VacJ/MlaA-MlaBCDEF prevents phospholipid accumulation at the bacterial surface, being the only system involved in maintaining membrane asymmetry identified in NTHi. We assessed the relationship among the NTHi VacJ/MlaA outer membrane lipoprotein, bacterial and exogenous fatty acids, and respiratory infection. The vacJ/mlaA gene inactivation increased NTHi fatty acid and phospholipid global content and fatty acyl specific species, which in turn increased bacterial susceptibility to hydrophobic antimicrobials, decreased NTHi epithelial infection, and increased clearance during pulmonary infection in mice with both normal lung function and emphysema, maybe related to their shared lung fatty acid profiles. Altogether, we provide evidence for VacJ/MlaA as a key bacterial factor modulating NTHi survival at the human airway upon exposure to hydrophobic molecules.

  17. Increasing incidence of invasive Haemophilus influenzae disease in adults, Utah, USA.

    PubMed

    Rubach, Matthew P; Bender, Jeffrey M; Mottice, Susan; Hanson, Kimberly; Weng, Hsin Y C; Korgenski, Kent; Daly, Judy A; Pavia, Andrew T

    2011-09-01

    Since the introduction of the Haemophilus influenzae type b vaccine, the incidence of invasive H. influenzae type b disease among children has fallen dramatically, but the effect on invasive H. influenzae disease among adults may be more complex. In this population-based study we examined the epidemiology and outcomes of invasive disease caused by typeable and nontypeable H. influenzae among Utah adults during 1998-2008. The overall incidence increased over the study period from 0.14/100,000 person-years in 1998 to 1.61/100,000 person-years in 2008. The average incidence in persons >65 years old was 2.74/100,000 person-years, accounting for 51% of cases and 67% of deaths. The incidence was highest for nontypeable H. influenzae (0.23/100,000 person-years), followed by H. influenzae type f (0.14/100,000 person-years). The case-fatality rate was 22%. The incidence of invasive H. influenzae in Utah adults appears to be increasing. Invasive H. influenzae infection disproportionately affected the elderly and was associated with a high mortality rate.

  18. An Application of Outer Membrane Protein P6-Specific Enzyme-Linked Immunosorbent Assay for Detection of Haemophilus influenzae in Middle Ear Fluids and Nasopharyngeal Secretions

    PubMed Central

    Hotomi, Muneki; Togawa, Akihisa; Kono, Masamitsu; Sugita, Gen; Sugita, Rinya; Fujimaki, Yutaka; Kamide, Yosuke; Uchizono, Akihiro; Kanesada, Keiko; Sawada, Shoichi; Okitsu, Naohiro; Masuda, Hisayo; Tanaka, Hideaki; Tanaka, Yumi; Yamanaka, Noboru

    2013-01-01

    An enzyme-linked immunosorbent assay specific to outer membrane protein P6 (P6-ELISA) was applied for detecting Haemophilus influenzae in middle ear fluids (MEFs) from acute otitis media (AOM) patients and in nasopharyngeal secretions (NPSs) from acute rhinosinusitis patients. P6-ELISA had a sensitivity of 83.3% for MEFs and 71.5% for NPSs and a specificity of 85.6% for MEFs and 92.5% for NPSs, respectively. Real-time PCR exhibited significant differences in the number of ompP1 gene copies among samples determined by P6-ELISA to be positive and negative for H. influenzae. However, because the P6-ELISA test has the reactivity in Haemophilus species include two commensals H. haemolyticus and H. parainfluenzae, it is thus a weak method in order to detect only NTHi correctly. Consequently, diagnosis using the P6-ELISA should be based on an overall evaluation, including the results of other related examinations and clinical symptoms to prevent misleading conclusions in clinical setting. PMID:24015192

  19. Recurrent posttraumatic meningitis due to nontypable Haemophilus influenzae: case report and review of the literature.

    PubMed

    Kunze, W; Müller, L; Kilian, M; Schuhmann, M U; Baumann, L; Handrick, W

    2008-02-01

    We report a case of relapsing Haemophilus influenzae meningitis in a boy at the age of nearly 3 years and 4.2 years who had been successfully vaccinated against H. influenzae serotype b (Hib). The pathogen was a nonencapsulated (nontypable) H. influenzae strain of biotypes III and VI, respectively. A rhinobasal impalement injury with development of a posttraumatic encephalocele is considered to be the predisposing condition. Review of the literature reveals that in patients systemically infected by nonencapsulated H. influenzae strains predisposing factors such as cerebrospinal fluid-shunts, implants and traumas are often found. To obtain further information on potential new disease patterns H. influenzae isolates from cerebrospinal fluid should be examined for capsule production and, if relevant, further characterized by capsular typing.

  20. Comparison of Established Diagnostic Methodologies and a Novel Bacterial smpB Real-Time PCR Assay for Specific Detection of Haemophilus influenzae Isolates Associated with Respiratory Tract Infections

    PubMed Central

    Reddington, Kate; Schwenk, Stefan; Tuite, Nina; Platt, Gareth; Davar, Danesh; Coughlan, Helena; Personne, Yoann; Gant, Vanya; Enne, Virve I.; Zumla, Alimuddin

    2015-01-01

    Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n = 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens. PMID:26109443

  1. Leaning in to the power of the possible: the crucial role of women scientists on preventing Haemophilus influenzae type b disease.

    PubMed

    O'Brien, Katherine L; Anderson, Porter W

    2014-03-01

    Beginning in an era when female scientists were a lonely minority, women have made major contributions to our understanding of Haemophilus influenzae type b (Hib) as a pathogen, its treatment and its prevention. The individual scientific and public health contributions, and their collective impact, are reviewed in the context of the development and successful implementation of highly efficacious Hib vaccines that are now being deployed to nearly every country worldwide for the prevention of life-threatening pediatric Hib disease.

  2. Meningitis due to ampicillin-and chloramphenicol-resistant Haemophilus influenzae type b in Canada. Case report and review

    PubMed Central

    Kabani, Amin; Joffe, Ari; Cadrain, Gisele; Jadavji, Taj

    1990-01-01

    The first report of a case of ampicillin- and chloramphenicol-resistant Haemophilus influenzae type b invasive infection in Canada is described in a four-month-old male with meningitis. He was treated with cefotaxime 200 mg/kg/day divided every 6 h and dexamethasone 0.6 mg/kg/day divided every 6 h, eventually recovering after a complicated course. Follow-up at 21 months showed mild to moderate global developmental delay. While chloramphenicol resistance is rare in North America, a case of meningitis initially unresponsive to ampicillin and chloramphenicol must be considered suspect for resistance. Third generation cephalosporins should be used for resistant cases. PMID:22553448

  3. Individual risk factors associated with nasopharyngeal colonization with Streptococcus pneumoniae and Haemophilus influenzae: a Japanese birth cohort study.

    PubMed

    Otsuka, Taketo; Chang, Bin; Shirai, Takatoshi; Iwaya, Atsushi; Wada, Akihito; Yamanaka, Noboru; Okazaki, Minoru

    2013-07-01

    The first step in a bacterial disease is the establishment of nasopharyngeal carriage. We conducted a birth cohort study to identify factors associated with colonization in healthy children and evaluate the serotype distributions and resistances of Streptococcus pneumoniae/Haemophilus influenzae. Nasopharyngeal cultures were obtained from 349 subjects at 5 time points coinciding with health checkups (4, 7, 10, 18 and 36 months). A total of 551 S. pneumoniae (penicillin resistance rate: 46.3%) and 301 H. influenzae (ampicillin resistance rate: 44.5%) isolates were obtained from 1654 samples. In this study, 47.5% and 60.9% of S. pneumoniae isolates were included in the serotypes of 7- and 13-valent pneumococcal conjugate vaccines, respectively. Analyzing by Cox proportional hazards models, cohabiting older sibling(s) attending day-care (hazard ratios: 2.064-3.518, P < 0.001) and an early start of day-care attendance by the subjects themselves (2.259-2.439, P < 0.001) were associated with a higher risk of early colonization regardless of their susceptibility. Recent exposure to antimicrobials was also significantly associated with increased risk of colonization (odds ratios: 2.032-2.999, P < 0.001) but not with resistance rates. This data indicated that introduction of appropriate antimicrobial usage in areas of overuse of antimicrobials could contribute to lower colonization of S. pneumoniae/H. influenzae, resulting in a decrease in the absolute number of resistant isolates. Strategies to control transmission at day-care centers or from older sibling(s) as well as appropriate use of antimicrobials are essential for reducing colonization and the absolute number of resistant isolates.

  4. Severe soft tissue infection of the lower extremity caused by Haemophilus influenzae (serotype f, biotype II) in an adult patient.

    PubMed

    Hagiya, Hideharu; Murase, Tomoko; Naito, Hiromichi; Hagioka, Shingo; Morimoto, Naoki

    2012-01-01

    The infection caused by non-b-type Haemophilus influenzae has been increasing in this Hib (H.influenzae serotype b) vaccination era. H.influenzae serotype f (Hif) is considered as one of those emerging pathogens. In general, H.influenzae is a common pathogen of such as pneumonia, otitis media, and meningitis, but is rare in soft tissue infection, especially at the extremity. We report a rare case of severe soft tissue infection caused by Hif which occurred at the lower extremity of immunocompetent adult patient.

  5. Biofilm-specific extracellular matrix proteins of nontypeable Haemophilus influenzae.

    PubMed

    Wu, Siva; Baum, Marc M; Kerwin, James; Guerrero, Debbie; Webster, Simon; Schaudinn, Christoph; VanderVelde, David; Webster, Paul

    2014-12-01

    Nontypeable Haemophilus influenzae (NTHi), a human respiratory tract pathogen, can form colony biofilms in vitro. Bacterial cells and the amorphous extracellular matrix (ECM) constituting the biofilm can be separated using sonication. The ECM from 24- and 96-h NTHi biofilms contained polysaccharides and proteinaceous components as detected by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) spectroscopy. More conventional chemical assays on the biofilm ECM confirmed the presence of these components and also DNA. Proteomics revealed eighteen proteins present in biofilm ECM that were not detected in planktonic bacteria. One ECM protein was unique to 24-h biofilms, two were found only in 96-h biofilms, and fifteen were present in the ECM of both 24- and 96-h NTHi biofilms. All proteins identified were either associated with bacterial membranes or cytoplasmic proteins. Immunocytochemistry showed two of the identified proteins, a DNA-directed RNA polymerase and the outer membrane protein OMP P2, associated with bacteria and biofilm ECM. Identification of biofilm-specific proteins present in immature biofilms is an important step in understanding the in vitro process of NTHi biofilm formation. The presence of a cytoplasmic protein and a membrane protein in the biofilm ECM of immature NTHi biofilms suggests that bacterial cell lysis may be a feature of early biofilm formation. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  6. Vaccines for Nontypeable Haemophilus influenzae: the Future Is Now

    PubMed Central

    2015-01-01

    Infections due to nontypeable Haemophilus influenzae result in enormous global morbidity in two clinical settings: otitis media in children and respiratory tract infections in adults with chronic obstructive pulmonary disease (COPD). Recurrent otitis media affects up to 20% of children and results in hearing loss, delays in speech and language development and, in developing countries, chronic suppurative otitis media. Infections in people with COPD result in clinic and emergency room visits, hospital admissions, and respiratory failure. An effective vaccine would prevent morbidity, help control health care costs, and reduce antibiotic use, a major contributor to the global crisis in bacterial antibiotic resistance. The widespread use of the pneumococcal conjugate vaccines is causing a relative increase in H. influenzae otitis media. The partial protection against H. influenzae otitis media induced by the pneumococcal H. influenzae protein D conjugate vaccine represents a proof of principle of the feasibility of a vaccine for nontypeable H. influenzae. An ideal vaccine antigen should be conserved among strains, have abundant epitopes on the bacterial surface, be immunogenic, and induce protective immune responses. Several surface proteins of H. influenzae have been identified as potential vaccine candidates and are in various stages of development. With continued research, progress toward a broadly effective vaccine to prevent infections caused by nontypeable H. influenzae is expected over the next several years. PMID:25787137

  7. Progressive Increase in Antimicrobial Resistance among Invasive Isolates of Haemophilus influenzae Obtained from Children Admitted to a Hospital in Kilifi, Kenya, from 1994 to 2002

    PubMed Central

    Scott, J. Anthony G.; Mwarumba, Salim; Ngetsa, Caroline; Njenga, Salome; Lowe, Brett S.; Slack, Mary P. E.; Berkley, James A.; Mwangi, Isaiah; Maitland, Kathryn; English, Mike; Marsh, Kevin

    2005-01-01

    Etest susceptibilities to amoxicillin, chloramphenicol, and trimethoprim-sulfamethoxazole of 240 invasive isolates of Haemophilus influenzae cultured from children in rural Kenya were 66%, 66%, and 38%, respectively. Resistance increased markedly over 9 years and was concentrated among serotype b isolates. In Africa, the increasing cost of treating resistant infections supports economic arguments for prevention through conjugate H. influenzae type b immunization. PMID:15980390

  8. Evaluation of a real-time polymerase chain reaction assay of the outer membrane protein P2 gene for the detection of Haemophilus parasuis in clinical samples.

    PubMed

    McDowall, Rebeccah; Slavic, Durda; MacInnes, Janet I; Cai, Hugh Y

    2014-04-01

    A real-time polymerase chain reaction (PCR) assay of the outer membrane protein (OMP) P2 gene was developed and used to test 97 putative Haemophilus parasuis pure cultures and 175 clinical tissue samples. With standard culture isolation as the gold standard, the diagnostic sensitivity and specificity of the PCR assay were determined to be 83% and 80%, respectively.

  9. Haemophilus influenzae vulvovaginitis associated with rhinitis caused by the same clone in a prepubertal girl.

    PubMed

    Chen, Xiao; Chen, Lifeng; Zeng, Wenjie; Zhao, Xiaofeng

    2017-06-01

    Vulvovaginitis caused by upper respiratory flora is generally considered to be the most common gynecological problem in prepubertal girls. To date, however, no direct evidence has been obtained for the underlying mechanism of transmission. This report describes a case of non-capsulate Haemophilus influenzae vulvovaginitis in a 6-year-old girl with a history of foreign bodies (cotton wool) in her vagina. Moreover, this girl had recurrent rhinitis for approximately 3 years. On Pulsed Field Gel Electrophoresis (PFGE) analysis the H. influenzae strain isolated from vaginal secretions and the H. influenzae strain isolated from nasal secretions were derived from the same clone. The patient was successfully treated with appropriate antibiotics. The present case might provide the first direct evidence of the nose-hand-vagina method of transmission. © 2017 Japan Society of Obstetrics and Gynecology.

  10. Biofilm-specific extracellular matrix proteins of non-typeable Haemophilus influenzae

    PubMed Central

    Wu, Siva; Baum, Marc M.; Kerwin, James; Guerrero-Given, Debbie; Webster, Simon; Schaudinn, Christoph; VanderVelde, David; Webster, Paul

    2014-01-01

    Non-typeable Haemophilus influenzae (NTHi), a human respiratory tract pathogen can form colony biofilms in vitro. Bacterial cells and the amorphous extracellular matrix (ECM) constituting the biofilm can be separated using sonication. The ECM from 24 hr and 96 hr NTHi biofilms contained polysaccharides and proteinaceous components as detected by NMR and FTIR spectroscopy. More conventional chemical assays on the biofilm ECM confirmed the presence of these components and also DNA. Proteomics revealed eighteen proteins present in biofilm ECM that were not detected in planktonic bacteria. One ECM protein was unique to 24 hr biofilms, two were found only in 96 hr biofilms, and fifteen were present in the ECM of both 24 hr and 96 hr NTHi biofilms. All proteins identified were either associated with bacterial membranes or were cytoplasmic proteins. Immunocytochemistry showed two of the identified proteins, a DNA-directed RNA polymerase and the outer membrane protein OMP P2, associated with bacteria and biofilm ECM. Identification of biofilm-specific proteins present in immature biofilms is an important step in understanding the in vitro process of NTHi biofilm formation. The presence of a cytoplasmic protein and a membrane protein in the biofilm ECM of immature NTHi biofilms suggests that bacterial cell lysis may be a feature of early biofilm formation. PMID:24942343

  11. Transcriptional profiling of Haemophilus parasuis SH0165 response to tilmicosin.

    PubMed

    Liu, Yingyu; Chen, Pin; Wang, Yang; Li, Wentao; Cheng, Shuang; Wang, Chunmei; Zhang, Anding; He, Qigai

    2012-12-01

    The Haemophilus parasuis respiratory tract pathogen poses a severe threat to the swine industry despite available antimicrobial therapies. To gain a more detailed understanding of the molecular mechanisms underlying H. parasuis response to tilmicosin treatment, microarray technology was applied to analyze the variation in gene expression of isolated H. parasuis SH0165 treated in vitro with subinhibitory (0.25 μg/ml) and inhibitory (8 μg/ml) concentrations. Tilmicosin treatment induced differential expression of 405 genes, the encoded products of which are mainly involved in the heat shock response, protein synthesis, and intracellular transportation. The subinhibitory and inhibitory concentrations of tilmicosin induced distinctive gene expression profiles of shared and unique changes, respectively. These changes included 302 genes mainly involved in protein export and the phosphotransferase system to sustain cell growth, and 198 genes mainly related to RNA polymerase, recombination, and repair to inhibit cell growth. In silico analysis of functions related to the differentially expressed genes suggested that adaptation of H. parasuis SH0165 to tilmicosin involves modulation of protein synthesis and membrane transport. Collectively, the genes comprising each transcriptional profile of H. parasuis response to tilmicosin provide novel insights into the physiological functions of this economically significant bacterium and may represent targets of future molecular therapeutic strategies.

  12. Comparative transcriptional profiling of tildipirosin-resistant and sensitive Haemophilus parasuis.

    PubMed

    Lei, Zhixin; Fu, Shulin; Yang, Bing; Liu, Qianying; Ahmed, Saeed; Xu, Lei; Xiong, Jincheng; Cao, Jiyue; Qiu, Yinsheng

    2017-08-08

    Numerous studies have been conducted to examine the molecular mechanism of Haemophilus parasuis resistance to antibiotic, but rarely to tildipirosin. In the current study, transcriptional profiling was applied to analyse the variation in gene expression of JS0135 and tildipirosin-resistant JS32. The growth curves showed that JS32 had a higher growth rate but fewer bacteria than JS0135. The cell membranes of JS32 and a resistant clinical isolate (HB32) were observed to be smoother than those of JS0135. From the comparative gene expression profile 349 up- and 113 downregulated genes were observed, covering 37 GO and 63 KEGG pathways which are involved in biological processes (11), cellular components (17), molecular function (9), cellular processes (1), environmental information processing (4), genetic information processing (9) and metabolism (49) affected in JS32. In addition, the relative overexpression of genes of the metabolism pathway (HAPS_RS09315, HAPS_RS09320), ribosomes (HAPS_RS07815) and ABC transporters (HAPS_RS10945) was detected, particularly the metabolism pathway, and verified with RT-qPCR. Collectively, the gene expression profile in connection with tildipirosin resistance factors revealed unique and highly resistant determinants of H. parasuis to macrolides that warrant further attention due to the significant threat of bacterial resistance.

  13. In vitro evaluation of nicotinamide riboside analogs against Haemophilus influenzae.

    PubMed

    Godek, C P; Cynamon, M H

    1990-08-01

    Exogenous NAD, nicotinamide mononucleotide, or nicotinamide riboside is required for the growth of Haemophilus influenzae. These compounds have been defined as the V-factor growth requirement. We have previously shown that the internalization of nicotinamide riboside is energy dependent and carrier mediated with saturation kinetics. Thionicotinamide riboside, 3-pyridinealdehyde riboside, 3-acetylpyridine riboside, and 3-aminopyridine riboside were prepared from their corresponding NAD analogs. These compounds and several other nicotinamide riboside analogs were evaluated for their ability to support the growth of H. influenzae and for their ability to block the uptake of [carbonyl-14C]nicotinamide riboside by H. influenzae. 3-Aminopyridine riboside blocked the uptake of [carbonyl-14C]nicotinamide riboside and inhibited the growth of H. influenzae when NAD, nicotinamide mononucleotide, or nicotinamide riboside served as the V factor. The antibacterial activity of 3-aminopyridine riboside was found to be specific for H. influenzae but had no effect on the growth of Staphylococcus aureus or Escherichia coli. In additional experiments by reversed-phase high-performance liquid chromatography, it was determined that whole cells of H. influenzae degrade 3-aminopyridine adenine dinucleotide to 3-aminopyridine riboside, which is then internalized. Inside the cell, 3-aminopyridine riboside has the ability to interfere with the growth of H. influenzae by an undetermined mechanism.

  14. Phosphorylcholine Allows for Evasion of Bactericidal Antibody by Haemophilus influenzae

    PubMed Central

    Clark, Sarah E.; Snow, Julian; Li, Jianjun; Zola, Tracey A.; Weiser, Jeffrey N.

    2012-01-01

    The human pathogen Haemophilus influenzae has the ability to quickly adapt to different host environments through phase variation of multiple structures on its lipooligosaccharide (LPS), including phosphorylcholine (ChoP). During colonization with H. influenzae, there is a selection for ChoP+ phase variants. In a murine model of nasopharyngeal colonization, this selection is lost in the absence of adaptive immunity. Based on previous data highlighting the importance of natural antibody in limiting H. influenzae colonization, the effect of ChoP expression on antibody binding and its bactericidal activity was investigated. Flow cytometric analysis revealed that ChoP+ phase variants had decreased binding of antibody to LPS epitopes compared to ChoP− phase variants. This difference in antibody binding correlated with increased survival of ChoP+ phase variants in the presence of antibody-dependent, complement-mediated killing. ChoP+ phase variants were also more resistant to trypsin digestion, suggesting a general effect on the physical properties of the outer membrane. Moreover, ChoP-mediated protection against antibody binding correlated with increased resilience of outer membrane integrity. Collectively, these data suggest that ChoP expression provides a selective advantage during colonization through ChoP-mediated effects on the accessibility of bactericidal antibody to the cell surface. PMID:22396641

  15. The effects of stopper drying on moisture levels of Haemophilus influenzae conjugate vaccine.

    PubMed

    Earle, J P; Bennett, P S; Larson, K A; Shaw, R

    1992-01-01

    The discovery and development of increasingly potent biological and pharmaceutical products have resulted in very small amounts of the active ingredient in final product formulations. Pediatric vaccines with sub-milliliter dose sizes pose unique problems for final formulation and lyophilization, especially when stabilizers used are present in small amounts or are hygroscopic. Lyophilized Haemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate) (PedvaxHIB) has a plug weight of about 3 mg in its final formulation. Microgram amounts of water absorbed by the lyophilized plug can cause drastic changes in the moisture content of the product. In a small percentage of the final containers absorption of moisture by the vaccine may cause aesthetic defects (plug collapse) over time, or at elevated temperatures. This paper describes drying methods developed to control residual moisture levels in stoppers used as final container closures. Results on the moisture stability of the product capped with dried and non-dried stoppers are presented.

  16. Comparison of Established Diagnostic Methodologies and a Novel Bacterial smpB Real-Time PCR Assay for Specific Detection of Haemophilus influenzae Isolates Associated with Respiratory Tract Infections.

    PubMed

    Reddington, Kate; Schwenk, Stefan; Tuite, Nina; Platt, Gareth; Davar, Danesh; Coughlan, Helena; Personne, Yoann; Gant, Vanya; Enne, Virve I; Zumla, Alimuddin; Barry, Thomas

    2015-09-01

    Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n = 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  17. Characterization and vaccine potential of outer membrane vesicles produced by Haemophilus parasuis

    DOE PAGES

    McCaig, William D.; Loving, Crystal L.; Hughes, Holly R.; ...

    2016-03-01

    Haemophilus parasuis is a Gram-negative bacterium that colonizes the upper respiratory tract of swine and is capable of causing a systemic infection, resulting in high morbidity and mortality. H. parasuis isolates display a wide range of virulence and virulence factors are largely unknown. Commercial bacterins are often used to vaccinate swine against H. parasuis, though strain variability and lack of cross-reactivity can make this an ineffective means of protection. Outer membrane vesicles (OMV) are spherical structures naturally released from the membrane of bacteria and OMV are often enriched in toxins, signaling molecules and other bacterial components. Examination of OMV structuresmore » has led to identification of virulence factors in a number of bacteria and they have been successfully used as subunit vaccines. We have isolated OMV from both virulent and avirulent strains of H. parasuis, have examined their protein content and assessed their ability to induce an immune response in the host. Lastly, vaccination with purified OMV derived from the virulent H. parasuis Nagasaki strain provided protection against challenge with a lethal dose of the bacteria.« less

  18. The Haemophilus influenzae Hap Autotransporter Binds to Fibronectin, Laminin, and Collagen IV

    PubMed Central

    Fink, Doran L.; Green, Bruce A.; St. Geme III, Joseph W.

    2002-01-01

    Nontypeable Haemophilus influenzae (NTHI) initiates infection by colonizing the upper respiratory tract mucosa. NTHI disease frequently occurs in the context of respiratory tract inflammation, where organisms encounter damaged epithelium and exposed basement membrane. In this study, we examined interactions between the H. influenzae Hap adhesin and selected extracellular matrix proteins. Hap is an autotransporter protein that undergoes autoproteolytic cleavage, with release of the adhesive passenger domain, Haps, from the bacterial cell surface. We found that Hap promotes bacterial adherence to purified fibronectin, laminin, and collagen IV and that Hap-mediated adherence is enhanced by inhibition of autoproteolysis. Adherence is inhibited by pretreatment of bacteria with a polyclonal antiserum recognizing Haps. Purified Haps binds with high affinity to fibronectin, laminin, and collagen IV but not to collagen II. Binding of Haps to fibronectin involves interaction with the 45-kDa gelatin-binding domain but not the 30-kDa heparin-binding domain of fibronectin. Taken together, these observations suggest that interactions between Hap and extracellular matrix proteins may play an important role in NTHI colonization of the respiratory tract. PMID:12183535

  19. Characterization and vaccine potential of outer membrane vesicles produced by Haemophilus parasuis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McCaig, William D.; Loving, Crystal L.; Hughes, Holly R.

    Haemophilus parasuis is a Gram-negative bacterium that colonizes the upper respiratory tract of swine and is capable of causing a systemic infection, resulting in high morbidity and mortality. H. parasuis isolates display a wide range of virulence and virulence factors are largely unknown. Commercial bacterins are often used to vaccinate swine against H. parasuis, though strain variability and lack of cross-reactivity can make this an ineffective means of protection. Outer membrane vesicles (OMV) are spherical structures naturally released from the membrane of bacteria and OMV are often enriched in toxins, signaling molecules and other bacterial components. Examination of OMV structuresmore » has led to identification of virulence factors in a number of bacteria and they have been successfully used as subunit vaccines. We have isolated OMV from both virulent and avirulent strains of H. parasuis, have examined their protein content and assessed their ability to induce an immune response in the host. Lastly, vaccination with purified OMV derived from the virulent H. parasuis Nagasaki strain provided protection against challenge with a lethal dose of the bacteria.« less

  20. Cost-effectiveness evaluation of vaccination against Haemophilus influenzae invasive diseases in France.

    PubMed

    Livartowski, A; Boucher, J; Detournay, B; Reinert, P

    1996-04-01

    A cost-effectiveness analysis of a vaccination program against Haemophilus influenzae type b (Hib) was conducted using French epidemiological data. The vaccine would be added as a fifth valence to the tetravalent vaccines (DTCP) widely used in France. The permanent sequelae of the Hib invasive diseases which might be avoided by vaccination were weighted to determine Quality Adjusted Life Years gained. In a stable French population of 3,746,000 children aged < 5 years old (1990), and for a followup period of ten years, the cost-effectiveness ratio of such a program for the French national health insurance system would equal 54,084 FF per year of life added or 34,050 FF per QALY. The net cost of the program during that period would be 1.02 billion FF for the French national health insurance system and 920 million FF for patients' families. Comparison of these projections with available information supports, a posteriori, the decision of the French government to authorize the licensing of the pentavalent vaccine.

  1. HtrA Is Important for Stress Resistance and Virulence in Haemophilus parasuis

    PubMed Central

    Zhang, Luhua; Li, Ying; Wen, Yiping; Lau, Gee W.; Huang, Xiaobo; Wu, Rui; Yan, Qigui; Huang, Yong; Zhao, Qin; Ma, Xiaoping

    2016-01-01

    Haemophilus parasuis is an opportunistic pathogen that causes Glässer's disease in swine, with polyserositis, meningitis, and arthritis. The high-temperature requirement A (HtrA)-like protease, which is involved in protein quality control, has been reported to be a virulence factor in many pathogens. In this study, we showed that HtrA of H. parasuis (HpHtrA) exhibited both chaperone and protease activities. Finally, nickel import ATP-binding protein (NikE), periplasmic dipeptide transport protein (DppA), and outer membrane protein A (OmpA) were identified as proteolytic substrates for HpHtrA. The protease activity reached its maximum at 40°C in a time-dependent manner. Disruption of the htrA gene from strain SC1401 affected tolerance to temperature stress and resistance to complement-mediated killing. Furthermore, increased autoagglutination and biofilm formation were detected in the htrA mutant. In addition, the htrA mutant was significantly attenuated in virulence in the murine model of infection. Together, these data demonstrate that HpHtrA plays an important role in the virulence of H. parasuis. PMID:27217419

  2. Evaluation of glutathione-binding protein A of Haemophilus parasuis as a vaccine candidate in a mouse model.

    PubMed

    Zhang, Yanhe; Li, Gang; Xie, Fang; Liu, Siguo; Wang, Chunlai

    2017-01-24

    The virulent strains of Haemophilus parasuis are the causative agents of Glässer's disease, which can cause systemic infection and result in polyserositis, meningitis and arthritis. The development of novel, effective vaccines would be beneficial to preventing H. parasuis infections. Here, we report a novel immunogenic protein, glutathione-binding protein A (GbpA), which can elicit a significant humoral antibody response and confer significant protection against challenge with a lethal dose of a highly virulent H. parasuis strain. The H. parasuis strain can be fully eliminated in the immunized mice. The results indicate that GbpA has the potential to be used as an effective component of a new vaccine against H. parasuis.

  3. The first reported case of possible Haemophilus influenzae type b vaccine failure from Kuwait and literature-review.

    PubMed

    Purohit, Prashant; Al-Obaid, Ina'am Ahmad; Omar, Nehad Gamal Al-Deen

    2014-01-01

    A 17-month-old vaccinated Kuwaiti boy presented with meningitis. The Haemophilus influenzae type b (Hib) capsular antigen was detected in his blood, CSF and urine. The microorganism failed to grow in culture. This case represents the first report of possible Hib vaccine failure from Kuwait. This report examines the possible reasons for this failure by reviewing the literature and emphasizes the need to broaden the definition of vaccine failure with the aim of optimizing the timing of the vaccine booster dose for prematurely born children and establishing continuous surveillance for Hib vaccine failure. Copyright © 2013 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  4. Pediatric invasive Haemophilus influenzae infections in Israel in the era of Haemophilus influenzae type b vaccine: a nationwide prospective study.

    PubMed

    Bamberger, Ellen E; Ben-Shimol, Shalom; Abu Raya, Bahaa; Katz, Amit; Givon-Lavi, Noga; Dagan, Ron; Srugo, Isaac

    2014-05-01

    The conjugated Haemophilus influenzae (Hi) type b vaccine caused a marked decrease in invasive Hi disease rates. Nonencapsulated Hi infection now constitutes most invasive Hi morbidity and mortality. This study examines invasive Hi infection incidence in Israel in the postvaccine era years, 2003-2012, and characterizes the epidemiology, clinical diagnosis and case fatality rates of invasive Hi disease in children <15 years of age. An ongoing, nationwide prospective surveillance program for invasive Hi infections in Israel. Epidemiologic and clinical data were collected. Diagnoses were classified as meningitis, pneumonia, bacteremia/sepsis and other clinical foci. Overall, 389 cases of invasive Hi infections were identified; 242 (62%) nontypable Hi (NTHi), 103 (26%) Hi type b (Hib) and 41 (11%) encapsulated non-b Hi (enbHi). Children <1 year of age accounted for 51% of the overall disease. Invasive Hi disease incidence in children <15 years of age was stable with a mean annual incidence (per 100,000) of 2.0 ± 0.4. The highest incidence of invasive Hi infections was among infants <1 year with rates of 6.2, 4.9, 1.6 and 12.7 for NTHi, Hib, enbHi and total Hi, respectively. The clinical diagnoses of NTHi and enbHi were similar, but differed from Hib with the former presenting mostly as isolated sepsis/bacteremia and the latter primarily as meningitis. Among children with invasive Hib infection, 40% were classified as vaccine failure. In the post-Hib vaccination era, invasive Hi morbidity and mortality are largely attributed to NTHi sepsis. Still, with the changing epidemiology of invasive Hi, continued surveillance of all Hi strains is justified.

  5. Aging and the Immune Response to the Haemophilus influenzae Type b Capsular Polysaccharide: Retention of the Dominant Idiotype and Antibody Function in the Elderly

    PubMed Central

    Lucas, Alexander H.; Reason, Donald C.

    1998-01-01

    Anti-Haemophilus influenzae b polysaccharide (Hib PS) antibodies elicited in elderly subjects following conjugate vaccination expressed a light-chain variable-region (VL)-associated idiotype and had functional activities similar to those previously observed in children and younger adults. These findings indicate that advanced age is not accompanied by shifts in the major VL component of the Hib PS-specific repertoire or by diminution of the protective function of antibodies. PMID:9529108

  6. Evaluation of a real-time polymerase chain reaction assay of the outer membrane protein P2 gene for the detection of Haemophilus parasuis in clinical samples

    PubMed Central

    McDowall, Rebeccah; Slavic, Durda; MacInnes, Janet I.; Cai, Hugh Y.

    2014-01-01

    A real-time polymerase chain reaction (PCR) assay of the outer membrane protein (OMP) P2 gene was developed and used to test 97 putative Haemophilus parasuis pure cultures and 175 clinical tissue samples. With standard culture isolation as the gold standard, the diagnostic sensitivity and specificity of the PCR assay were determined to be 83% and 80%, respectively. PMID:24688178

  7. Nontypeable Haemophilus influenzae initiates formation of neutrophil extracellular traps.

    PubMed

    Juneau, Richard A; Pang, Bing; Weimer, Kristin E D; Armbruster, Chelsie E; Swords, W Edward

    2011-01-01

    Nontypeable Haemophilus influenzae (NTHI) is a leading cause of otitis media infections, which are often chronic and/or recurrent in nature. NTHI and other bacterial species persist in vivo within biofilms during otitis media and other persistent infections. These biofilms have a significant host component that includes neutrophil extracellular traps (NETs). These NETs do not mediate clearance of NTHI, which survives within NET structures by means of specific subpopulations of lipooligosaccharides on the bacterial surface that are determinants of biofilm formation in vitro. In this study, the ability of NTHI and NTHI components to initiate NET formation was examined using an in vitro model system. Both viable and nonviable NTHI strains were shown to promote NET formation, as did preparations of bacterial DNA, outer membrane proteins, and lipooligosaccharide (endotoxin). However, only endotoxin from a parental strain of NTHI exhibited equivalent potency in NET formation to that of NTHI. Additional studies showed that NTHI entrapped within NET structures is resistant to both extracellular killing within NETs and phagocytic killing by incoming neutrophils, due to oligosaccharide moieties within the lipooligosaccharides. Thus, we concluded that NTHI elicits NET formation by means of multiple pathogen-associated molecular patterns (most notably endotoxin) and is highly resistant to killing within NET structures. These data support the conclusion that, for NTHI, formation of NET structures may be a persistence determinant by providing a niche within the middle-ear chamber.

  8. Direct detection of the multidrug resistance genome of Haemophilus influenzae in cerebrospinal fluid of children: implications for treatment of meningitis.

    PubMed

    Saha, Samir K; Darmstadt, Gary L; Baqui, Abdullah H; Islam, Nurul; Qazi, Shamim; Islam, Maksuda; El Arifeen, Shams; Santosham, Mathuram; Black, Robert E; Crook, Derrick W

    2008-01-01

    Multidrug resistance (MDR), specifically to ampicillin and chloramphenicol, has complicated the treatment of Haemophilus influenzae type b (Hib) meningitis. This is worsened by use of prior antibiotics, which limits identification of the causative agent by culture and increases reliance on antigen detection. We aimed to develop a PCR assay for detecting the family of Haemophilus integrating and conjugative elements (ICEs) represented by ICEHin1056 among antibiotic resistant Hib, and then apply this directly to CSF to diagnose Hib meningitis and predict organism susceptibility, irrespective of culture results. Primers specific for orf 51 of ICEHin1056 were designed and multiplexed with Bex primers, specific for H. influenzae, and tested on culture positive and negative cases. Of 73 Hib isolates, orf 51 PCR amplicons, predicting the presence of ICEs, were found in all 33 MDR isolates while only in 1 of 33 sensitive strains. The remaining 7 ampicillin susceptible, chloramphenicol and tetracycline resistant strains did not produce a PCR product to orf 51. PCR amplification from CSF specimens of these culture positive cases produced identical results with 100% and 97% positive and negative predictive values, respectively. Multiplex PCR to detect Bex and orf 51 identified another 16 MDR Hib cases among 81 culture-negative CSF samples. Direct PCR for orf 51 in CSF identified resistance pattern of 51% more Hib strains than culture alone (110 versus 73). The ability to detect MDR, in culture negative Hib meningitis cases has significant implications for better directing antibiotic treatment of meningitis cases and thus for preventing disability and death.

  9. Serotypes, antimicrobial susceptibility, and beta-lactam resistance mechanisms of clinical Haemophilus influenzae isolates from Bulgaria in a pre-vaccination period.

    PubMed

    Setchanova, Lena Petrova; Kostyanev, Tomislav; Markovska, Rumyana; Miloshev, George; Mitov, Ivan Gergov

    2013-02-01

    To determine the serotypes, antimicrobial susceptibility, and beta-lactam resistance mechanisms of Haemophilus influenzae strains isolated from invasive and respiratory tract infections (RTIs) prior to the introduction of Haemophilus influenzae type b (Hib) vaccination in Bulgaria. A total of 259 isolates were serotyped by polymerase chain reaction. Susceptibility to antibiotics and beta-lactamase production were determined, and DNA sequencing of the ftsI gene was performed for ampicillin non-susceptible strains. The invasive H. influenzae infections in children were mainly due to serotype b (94.5% in meningitis and 88.9% in other invasive cases). Non-typeable strains (97.4%) were the most frequently found H. influenzae strains in RTIs both in children and adults. Non-susceptibility to ampicillin occurred in 22% of all strains. Ceftriaxone and levofloxacin were the most active agents tested. Ampicillin resistance occurred in 34.4% of invasive strains, and beta-lactamase production was the only mechanism found. Among respiratory tract isolates, ampicillin non-susceptible strains (18%) were classified into the following groups: beta-lactamase-positive, ampicillin-resistant (BLPAR) strains (7.2%); beta-lactamase-negative, ampicillin-non-susceptible (BLNAR) strains (8.2%); and beta- lactamase-positive, amoxicillin-clavulanate-resistant (BLPACR) strains (2.6%). Among 21 BLNAR and BLPACR strains there were 9 different patterns of multiple-amino acid substitutions in penicillin-binding protein 3. Of these, most isolates (81.0%) belonged to group II, defined by the Asn526Lys substitution. Beta-lactamase production was more common among invasive strains than in respiratory isolates. BLNAR and BLPACR H. influenzae were found only among respiratory tract isolates.

  10. Haemophilus influenzae type B meningitis: Is there a re-emergence? 24 years of experience in a children's hospital.

    PubMed

    Gentile, Angela; Martínez, Ana C; Juarez, María Del V; Lución, María F; Burgo, Candela; Della Latta, María P; Rapapor, Solana; Romanin, Viviana; Turco, Marisa

    2017-06-01

    Haemophilus influenzae type B (Hib) used to be the main cause of bacterial meningitis in children younger than 5 years old. Following the introduction of the Hib vaccine in the immunization schedule (1998), its incidence reduced significantly but it has increased over the last years. The objectives of this study included describing the characteristics and analyzing the epidemic curve of Haemophilus influenzae type B (Hib) meningitis by comparing the pre- and postimmunization periods. Time-series study. All patients hospitalized with Hib meningitis at Hospital de Niños "R. Gutiérrez" (January 1992-May 2016). Hospitalization rates were compared before (pre-immunization) and after (post-immunization) the introduction of the Hib vaccine. The post-immunization period was divided into three similar periods. Eighty-five patients with Hib meningitis were admitted (73.3% in the pre-immunization period). No differences were observed in relation to the clinical and sociodemographic characteristics of cases in both periods. Pre-immunization: 10.5 cases/year; postimmunization: 0.7 cases/year. As of 2014, the rate has increased. Lethality rate: 4.8% (all preimmunization). Post-immunization data (n= 15): 40% had completed their primary immunization schedule, 40% were delayed on the immunization schedule for their age. Overall reduction in the hospital rate of Hib meningitis by 89.8% (95% confidence interval: -82.79-93.96%, p < 0.001) in the post-immunization period. The analysis of the different post-immunization periods shows a decline in reduction over time. A very significant reduction in hospitalizations due to Hib meningitis was observed after the Hib vaccine was introduced; however, over the past years, the number of cases has increased although no changes have been observed in patient characteristics.

  11. Rapid Discrimination of Haemophilus influenzae, H. parainfluenzae, and H. haemolyticus by Fluorescence In Situ Hybridization (FISH) and Two Matrix-Assisted Laser-Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS) Platforms

    PubMed Central

    Frickmann, Hagen; Christner, Martin; Donat, Martina; Berger, Anja; Essig, Andreas; Podbielski, Andreas; Hagen, Ralf Matthias; Poppert, Sven

    2013-01-01

    Background Due to considerable differences in pathogenicity, Haemophilus influenzae, H. parainfluenzae and H. haemolyticus have to be reliably discriminated in routine diagnostics. Retrospective analyses suggest frequent misidentifications of commensal H. haemolyticus as H. influenzae. In a multi-center approach, we assessed the suitability of fluorescence in situ hybridization (FISH) and matrix-assisted laser-desorption-ionization time-of-flight mass-spectrometry (MALDI-TOF-MS) for the identification of H. influenzae, H. parainfluenzae and H. haemolyticus to species level. Methodology A strain collection of 84 Haemophilus spp. comprising 50 H. influenzae, 25 H. parainfluenzae, 7 H. haemolyticus, and 2 H. parahaemolyticus including 77 clinical isolates was analyzed by FISH with newly designed DNA probes, and two different MALDI-TOF-MS systems (Bruker, Shimadzu) with and without prior formic acid extraction. Principal Findings Among the 84 Haemophilus strains analyzed, FISH led to 71 correct results (85%), 13 uninterpretable results (15%), and no misidentifications. Shimadzu MALDI-TOF-MS resulted in 59 correct identifications (70%), 19 uninterpretable results (23%), and 6 misidentifications (7%), using colony material applied directly. Bruker MALDI-TOF-MS with prior formic acid extraction led to 74 correct results (88%), 4 uninterpretable results (5%) and 6 misidentifications (7%). The Bruker MALDI-TOF-MS misidentifications could be resolved by the addition of a suitable H. haemolyticus reference spectrum to the system's database. In conclusion, no analyzed diagnostic procedure was free of errors. Diagnostic results have to be interpreted carefully and alternative tests should be applied in case of ambiguous test results on isolates from seriously ill patients. PMID:23646201

  12. Haemophilus influenzae: an underrated cause of vulvovaginitis in young girls.

    PubMed Central

    Cox, R A

    1997-01-01

    AIMS: To establish the common pathogens associated with infective vulvovaginitis in young girls in the local population and to determine current management of this condition. METHODS: A prospective laboratory based survey was carried out over 19 months. A questionnaire was then sent to local general practitioners and hospital doctors. RESULTS: One hundred and six swabs were received during the study period of which 43 (40.5%) yielded organisms recognised as causes of vulvovaginitis. The most common pathogen was group A beta haemolytic streptococcus (19), with Haemophilus influenzae the second most common (11). Candida was isolated on nine occasions. The users' questionnaire had an overall response rate of 52%. Forty one per cent of respondents nominated candida as the most common cause of this condition. Forty six per cent were aware that beta haemolytic streptococci caused juvenile vulvovaginitis, but only four (3.6%) knew that H influenzae was a possible pathogen. The most popular agent for empirical treatment of vulvovaginitis was topical clotrimazole cream, although 24 respondents (22%) prescribed antibiotics that are active against both group A beta haemolytic streptococci and H influenzae. CONCLUSIONS: Although H influenzae is the second most common infective cause of juvenile vulvovaginitis in the local population, most doctors managing these patients were unaware of its importance and may not be prescribing appropriate empirical treatment. Images PMID:9389978

  13. Structural Determinants of Autoproteolysis of the Haemophilus influenzae Hap Autotransporter▿

    PubMed Central

    Kenjale, Roma; Meng, Guoyu; Fink, Doran L.; Juehne, Twyla; Ohashi, Tomoo; Erickson, Harold P.; Waksman, Gabriel; St. Geme, Joseph W.

    2009-01-01

    Haemophilus influenzae is a gram-negative bacterium that initiates infection by colonizing the upper respiratory tract. The H. influenzae Hap autotransporter protein mediates adherence, invasion, and microcolony formation in assays with respiratory epithelial cells and presumably facilitates colonization. The serine protease activity of Hap is associated with autoproteolytic cleavage and extracellular release of the HapS passenger domain, leaving the Hapβ C-terminal domain embedded in the outer membrane. Cleavage occurs most efficiently at the LN1036-37 peptide bond and to a lesser extent at three other sites. In this study, we utilized site-directed mutagenesis, homology modeling, and assays with a peptide library to characterize the structural determinants of Hap proteolytic activity and cleavage specificity. In addition, we used homology modeling to predict the S1, S2, and S4 subsite residues of the Hap substrate groove. Our results indicate that the P1 and P2 positions at the Hap cleavage sites are critical for cleavage, with leucine preferred over larger hydrophobic residues or other amino acids in these positions. The substrate groove is formed by L263 and N274 at the S1 subsite, R264 at the S2 subsite, and E265 at the S4 subsite. This information may facilitate design of approaches to block Hap activity and interfere with H. influenzae colonization. PMID:19687208

  14. In vitro evaluation of nicotinamide riboside analogs against Haemophilus influenzae.

    PubMed Central

    Godek, C P; Cynamon, M H

    1990-01-01

    Exogenous NAD, nicotinamide mononucleotide, or nicotinamide riboside is required for the growth of Haemophilus influenzae. These compounds have been defined as the V-factor growth requirement. We have previously shown that the internalization of nicotinamide riboside is energy dependent and carrier mediated with saturation kinetics. Thionicotinamide riboside, 3-pyridinealdehyde riboside, 3-acetylpyridine riboside, and 3-aminopyridine riboside were prepared from their corresponding NAD analogs. These compounds and several other nicotinamide riboside analogs were evaluated for their ability to support the growth of H. influenzae and for their ability to block the uptake of [carbonyl-14C]nicotinamide riboside by H. influenzae. 3-Aminopyridine riboside blocked the uptake of [carbonyl-14C]nicotinamide riboside and inhibited the growth of H. influenzae when NAD, nicotinamide mononucleotide, or nicotinamide riboside served as the V factor. The antibacterial activity of 3-aminopyridine riboside was found to be specific for H. influenzae but had no effect on the growth of Staphylococcus aureus or Escherichia coli. In additional experiments by reversed-phase high-performance liquid chromatography, it was determined that whole cells of H. influenzae degrade 3-aminopyridine adenine dinucleotide to 3-aminopyridine riboside, which is then internalized. Inside the cell, 3-aminopyridine riboside has the ability to interfere with the growth of H. influenzae by an undetermined mechanism. Images PMID:2145800

  15. [Surveillance of Haemophilus influenzae serotypes in Argentina from 2005 to 2010 during the Haemophilus influenzae type b conjugate vaccine era].

    PubMed

    Efron, Adriana M; Moscoloni, María A; Reijtman, Vanesa R; Regueira, Mabel

    2013-01-01

    The introduction of the Haemophilus influenzae type b vaccine in the immunization programs of many countries has greatly reduced this invasive disease and the carriage caused by this serotype, also increasing other capsular types and non-capsular isolations. There were 313 isolations of H. influenzae under study, which were recovered from a sterile site coming from pediatric and adult patients carrying the invasive disease. Patients were treated at 90 different hospitals belonging to the Red Nacional de Laboratorios para Meningitis e Infecciones Respiratorias Agudas Bacterianas (National Lab Network for Meningitis and Acute Bacterial Respiratory Infections) from 2005 to 2010 for the following disorders: pneumonia, 40.3% (n=126), meningitis, 30.0% (n=94) and bacteremia, 26.5% (n=83). In pediatric patients (n=279), the highest frequency of isolations corresponded to children under the age of 2 years, 74.5% (n=208). Regarding type distribution, 61.3% corresponded to non-capsular H. influenzae (n=192), 20.1% to type b (n=63), 11.2% to type a (n=35), 4.8% to type f, and 2.6% to other types. Capsular H. influenzae was predominant in meningitis whereas non-capsular H. influenzae in pneumonia and bacteremia. The biotype was determined in 306 isolations. The totality (100%) of type a (n=35) was biotype II whereas 66.7% of type b (n=63) was biotype I. Slide agglutination and PCR tests were used in 220 isolations. There was a match of 0.982 (IC: 0.92-1.00) between them. During the last year, there was a great increase in type b, showing the importance of clinical and laboratory-based surveillance of the invasive disease caused by H. influenzae. Copyright © 2013 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

  16. Cigarette Smoke Exposure Exacerbates Lung Inflammation and Compromises Immunity to Bacterial Infection

    PubMed Central

    Lugade, Amit A.; Bogner, Paul N.; Thatcher, Thomas H.; Sime, Patricia J.; Phipps, Richard P.; Thanavala, Yasmin

    2014-01-01

    The detrimental impact of tobacco on human health is clearly recognized and despite aggressive efforts to prevent smoking, close to one billion individuals worldwide continue to smoke. People with chronic obstructive pulmonary disease (COPD) are susceptible to recurrent respiratory infections with pathogens, including non-typeable Haemophilus influenzae (NTHI), yet the reasons for this increased susceptibility are poorly understood. As mortality rapidly increases with multiple exacerbations, development of protective immunity is critical to improving patient survival. Acute NTHI infection has been studied in the context of cigarette smoke exposure, but this is the first study to investigate chronic infection and the generation of adaptive immune responses to NTHI following chronic smoke exposure. After chronic NTHI infection, mice that had previously been exposed to cigarette smoke developed increased lung inflammation and compromised adaptive immunity relative to air-exposed controls. Importantly, NTHI-specific T cells from mice exposed to cigarette smoke produced lower levels of IFN-γ and IL-4, and B cells produced reduced levels of antibodies against outer membrane lipoprotein P6, with impaired IgG1, IgG2a and IgA class-switching. However, production of IL-17, which is associated with neutrophilic inflammation, was enhanced. Interestingly, cigarette smoke exposed mice exhibited a similar defect in the generation of adaptive immunity following immunization with P6. Our study has conclusively demonstrated that cigarette smoke exposure has a profound suppressive effect on the generation of adaptive immune responses to NTHI and suggests the mechanism by which prior cigarette smoke exposure predisposes COPD patients to recurrent infections, leading to exacerbations and contributing to mortality. PMID:24752444

  17. Incidence of childhood Haemophilus influenzae type b meningitis in Sri Lanka.

    PubMed

    Batuwanthudawe, Ranjith; Rajapakse, Lalani; Somaratne, Pranitha; Dassanayake, Malka; Abeysinghe, Nihal

    2010-05-01

    To demonstrate the burden of Haemophilus influenzae type b (Hib) disease in Sri Lanka and provide information for decision-making in public health planning and vaccine introduction. This was a prospective, population-based study carried out in 2004, to describe the epidemiology and calculate the incidence of meningitis caused by Hib in children <5 years of age in the district of Colombo, Sri Lanka. Hib was identified in cerebrospinal fluid (CSF) specimens by culture and antigen detection (latex agglutination test; LAT). The lumbar puncture rate in children <5 years of age was 1.9%. A causative bacterial organism was identified in 108 meningitis cases, and in 54 (50%) this was Hib. The LAT increased the Hib detection rate in CSF four-fold. In 2004, the annual incidence of Hib meningitis in Colombo was 20.1 cases per 100000 children aged <5 years. This study is the first from Sri Lanka reporting the Hib meningitis incidence rate pre-vaccine introduction. The reported incidence rate is one of the highest from the Asian region, but is likely an underestimation considering the difficulties in the laboratory identification of Hib. Copyright 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Invasive Haemophilus influenzae Serotype f Case Reports in Mazovia Province, Poland

    PubMed Central

    Golebiewska, Anna; Kuch, Alicja; Gawrońska, Agnieszka; Albrecht, Piotr; Skoczyńska, Anna; Radzikowski, Andrzej; Kutylowska, Ewa; Feleszko, Wojciech

    2016-01-01

    Abstract After successful introduction of anti-Haemophilus influenzae (Hi) serotype b vaccination program in Poland, invasive non-b or nontypeable H. influenzae infections have been reported more frequently alike in other countries all over the world. In this paper, we report 2 cases of H. influenzae serotype f (Hif) meningitis with severe clinical presentations which are rarely seen in previously healthy children. The first case is a 6-year-old girl who was admitted to pediatric ward with signs of meningitis. Laboratory tests confirmed bacteremic meningitis caused by Hif. The girl responded very well to administered treatment and recovered without any further complications. No underlying comorbidities were found. The second patient was a 4-year-old boy who, in course of Hif bacteremic meningitis, developed rapid septicemia and, despite aggressive treatment, died within a few hours of hospitalization. The child's past history was unremarkable. By presenting these cases, we would like to remind clinicians that invasive non-b Hi infections can become fatal not only in the group of the youngest children or children with coexisting comorbidities, as most commonly reported in the worldwide literature. At the same time, we want to emphasize the legitimacy of constant monitoring Hi epidemiology in order to take accurate actions if necessary. PMID:26844500

  19. Invasive Haemophilus influenzae Serotype f Case Reports in Mazovia Province, Poland.

    PubMed

    Golebiewska, Anna; Kuch, Alicja; Gawrońska, Agnieszka; Albrecht, Piotr; Skoczyńska, Anna; Radzikowski, Andrzej; Kutylowska, Ewa; Feleszko, Wojciech

    2016-02-01

    After successful introduction of anti-Haemophilus influenzae (Hi) serotype b vaccination program in Poland, invasive non-b or nontypeable H. influenzae infections have been reported more frequently alike in other countries all over the world. In this paper, we report 2 cases of H. influenzae serotype f (Hif) meningitis with severe clinical presentations which are rarely seen in previously healthy children.The first case is a 6-year-old girl who was admitted to pediatric ward with signs of meningitis. Laboratory tests confirmed bacteremic meningitis caused by Hif. The girl responded very well to administered treatment and recovered without any further complications. No underlying comorbidities were found. The second patient was a 4-year-old boy who, in course of Hif bacteremic meningitis, developed rapid septicemia and, despite aggressive treatment, died within a few hours of hospitalization. The child's past history was unremarkable.By presenting these cases, we would like to remind clinicians that invasive non-b Hi infections can become fatal not only in the group of the youngest children or children with coexisting comorbidities, as most commonly reported in the worldwide literature. At the same time, we want to emphasize the legitimacy of constant monitoring Hi epidemiology in order to take accurate actions if necessary.

  20. Characterization of Haemophilus parasuis isolated from Brazilian swine through serotyping, AFLP and PFGE.

    PubMed

    Castilla, Karina Salvagni; de Gobbi, Débora Dirani Sena; Moreno, Luisa Zanolli; Paixão, Renata; Coutinho, Tania Alen; dos Santos, José Lúcio; Moreno, Andrea Micke

    2012-06-01

    Haemophilus parasuis infection in pigs is characterized by fibrinous polyserositis, arthritis and meningitis. Despite the fact that traditional diagnosis is based on herd history, clinical signs, bacterial isolation and serotyping, molecular-based methods are alternatives for species-specific tests and epidemiological studies. The aim of this study was to characterize H. parasuis field strains from different states of Brazil, employing serotyping and genotyping methods. Serotyping revealed that serovar 4 was the most prevalent (26.1%), followed by serovars 5 (17.4%), 14 (8.7%), 13 (4.4%) and 2 (4.4%), whereas 39% of the strains were considered as untypeable. AFLP with a single enzyme and PFGE were able to type all isolates tested, generating 34 and 20 different profiles, respectively, including untypeable strains. Besides the slightly higher discrimination index presented by AFLP, PFGE with Not I restriction enzyme showed a better correlation with epidemiological data, grouping strains of the same serovar, animal or farm origin. The results indicated AFLP and PFGE as valuable tools for typing H. parasuis isolates collected in Brazil. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Selective differential human blood bilayer media for isolation of Gardnerella (Haemophilus) vaginalis.

    PubMed Central

    Totten, P A; Amsel, R; Hale, J; Piot, P; Holmes, K K

    1982-01-01

    New selective and differential human blood bilayer agar media with Tween 80 (HBT medium) or without Tween 80 (HB medium), developed for the isolation of Gardnerella (Haemophilus) vaginalis, permitted significantly higher G. vaginalis isolation rates than have been obtained for other media used for this purpose. HB medium consists of a basal layer of Columbia agar base containing colistin and naladixic acid with added amphotericin B and an overlayer of the same composition plus 5% human blood. HBT agar also contains Proteose Peptone No. 3 (Difco Laboratories) and Tween 80 in the basal layer and the overlayer. Both Tween 80 and the bilayer composition enhanced G. vaginalis production of human blood hemolysis, permitting detection of this organism even in the presence of heavy growth of other vaginal flora. The use of HB or HBT medium thus permitted the demonstration that G. vaginalis was present in vaginal fluid from a large percentage (up to 68%) of normal women. However, the concentration of G. vaginalis was found by semiquantitative analysis to be significantly higher in vaginal fluid from women with nonspecific vaginitis than in fluid from normal women. Images PMID:6764766

  2. Resistance of non-typeable Haemophilus influenzae biofilms is independent of biofilm size

    PubMed Central

    Reimche, Jennifer L.; Kirse, Daniel J.; Whigham, Amy S.; Swords, W. Edward

    2016-01-01

    Abstract The inflammatory middle ear disease known as otitis media can become chronic or recurrent in some cases due to failure of the antibiotic treatment to clear the bacterial etiological agent. Biofilms are known culprits of antibiotic-resistant infections; however, the mechanisms of resistance for non-typeable Haemophilus influenzae biofilms have not been completely elucidated. In this study, we utilized in vitro static biofilm assays to characterize clinical strain biofilms and addressed the hypothesis that biofilms with greater biomass and/or thickness would be more resistant to antimicrobial-mediated eradication than thinner and/or lower biomass biofilms. Consistent with previous studies, antibiotic concentrations required to eliminate biofilm bacteria tended to be drastically higher than concentrations required to kill planktonic bacteria. The size characterizations of the biofilms formed by the clinical isolates were compared to their minimum biofilm eradication concentrations for four antibiotics. This revealed no correlation between biofilm thickness or biomass and the ability to resist eradication by antibiotics. Therefore, we concluded that biofilm size does not play a role in antibiotic resistance, suggesting that reduction of antibiotic penetration may not be a significant mechanism for antibiotic resistance for this bacterial opportunist. PMID:27956464

  3. The burden of nonencapsulated Haemophilus influenzae in children and potential for prevention.

    PubMed

    Gkentzi, Despoina; Slack, Mary P E; Ladhani, Shamez N

    2012-06-01

    In countries with established Haemophilus influenzae serotype b (Hib) immunization programmes, nonencapsulated H. influenzae (ncHi) is responsible for most invasive H. influenzae infections across all age groups and is associated with higher case fatality. A pneumococcal conjugate vaccine has recently been licensed, which may potentially also protect against invasive H. influenzae infections. Invasive ncHi disease is uncommon in childhood but has a much higher incidence in the first month of life. Most neonates with invasive ncHi infections are born prematurely and develop septicaemia in the first 48 h of life which can be fatal. After this period, invasive ncHi incidence falls rapidly and remains low throughout childhood. Most infants and children who develop invasive ncHi disease have significant underlying comorbidities, particularly neurological disease, malignancy and other conditions requiring immunosuppressive therapy. Although characteristically associated with respiratory tract infections, at least a quarter of invasive ncHi infections present with meningitis. A vaccine against ncHi could have an important preventive role in children with comorbidities. Future studies should focus on assessing specific risk factors for neonatal and childhood ncHi disease and long-term outcomes of children with invasive ncHi meningitis.

  4. HtrA Is Important for Stress Resistance and Virulence in Haemophilus parasuis.

    PubMed

    Zhang, Luhua; Li, Ying; Wen, Yiping; Lau, Gee W; Huang, Xiaobo; Wu, Rui; Yan, Qigui; Huang, Yong; Zhao, Qin; Ma, Xiaoping; Wen, Xintian; Cao, Sanjie

    2016-08-01

    Haemophilus parasuis is an opportunistic pathogen that causes Glässer's disease in swine, with polyserositis, meningitis, and arthritis. The high-temperature requirement A (HtrA)-like protease, which is involved in protein quality control, has been reported to be a virulence factor in many pathogens. In this study, we showed that HtrA of H. parasuis (HpHtrA) exhibited both chaperone and protease activities. Finally, nickel import ATP-binding protein (NikE), periplasmic dipeptide transport protein (DppA), and outer membrane protein A (OmpA) were identified as proteolytic substrates for HpHtrA. The protease activity reached its maximum at 40°C in a time-dependent manner. Disruption of the htrA gene from strain SC1401 affected tolerance to temperature stress and resistance to complement-mediated killing. Furthermore, increased autoagglutination and biofilm formation were detected in the htrA mutant. In addition, the htrA mutant was significantly attenuated in virulence in the murine model of infection. Together, these data demonstrate that HpHtrA plays an important role in the virulence of H. parasuis. Copyright © 2016 Zhang et al.

  5. Pediatric orbital cellulitis in the Haemophilus influenzae vaccine era.

    PubMed

    Sharma, Abhishek; Liu, Eugene S; Le, Tran D; Adatia, Feisal A; Buncic, J Raymond; Blaser, Susan; Richardson, Susan

    2015-06-01

    To evaluate the microbiology of pediatric orbital cellulitis in blood cultures and abscess drainage cultures following the introduction of the Haemophilus influenzae serotype b (Hib) vaccine. The medical records of all pediatrics patients (aged <18 years) at a tertiary pediatric hospital during the period January 2000 to July 2011 with a computed tomography orbital imaging querying "orbital cellulitis," "periorbital cellulitis," "preseptal cellulitis," or "post-septal cellulitis" were retrospectively reviewed. The records, microbiology, and radiology of these patients were reviewed to assess the rates and complications of H. influenzae orbital cellulitis, including bacteremia and meningitis. A total of 149 patients were diagnosed with preseptal or orbital cellulitis, of whom 101 (mean age, 7.2 ± 4.0) had true orbital cellulitis. No patients grew H. influenzae from blood cultures. Of the 101 patients, 30 (29.7%) required surgical drainage and had abscess drainage fluid sent for microbiology. Of these, 18 (64.3%) had a positive culture: 4 (13.3%) grew H. influenzae from their abscess drainage fluid samples; 1 grew H. influenzae alone; and 3 had mixed growth that included H. influenzae. The patients positive for H. influenzae were significantly older and had significantly larger abscesses. Although there were no cases of H. influenzae bacteremia or meningitis in our cases of orbital cellulitis, abscess drainage fluid microbiology indicated that H. influenzae remains a cause of orbital cellulitis. H. influenzae abscess volume was significantly larger than other bacterial abscesses and was associated with abscesses of mixed bacterial growth in older children. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  6. Intraperitoneal inoculation of Haemophilus influenzae local isolates in BALB/c mice model in the presence and absence of virulence enhancement agents.

    PubMed

    Mojgani, N; Maldjae, V; Rahbar, M; Mirafzali, S M; Khoshnood, S; Hatami, A

    2013-01-01

    Haemophilus influenzae (Hi), predominantly type b accounts for approximately 4% of cases of community-acquired and nosocomial meningitis, in adults. The objective of this study was to evaluate the pathogenicity of local Hi isolates (type b, f and non-typable) in BALB/c mice in the presence of virulence enhancement agents. Three different concentrations of the Hi isolates were inoculated intraperitoneally in BALB/c mice in the presence of 2% hemoglobin and 4% mucin as virulence enhancing agents (VEA). The ability of the isolates to produce bacteremia, the percent survival and lethal dose (LD50) were recorded in different challenge groups. The 3 Haemophilus influenzae type b (Hib) isolates used in study were able to show virulence in BALB/c mice model only in the presence of VEA and their LD50 decreased significantly when 2% hemoglobin and 4% mucin were used. All survived animals showed bacteremia within 4 h of inoculation which was cleared within 18 h. Significant differences (P<0.01) in the virulence and survival percentage of Hib challenge groups were observed based on their dose of inoculation and VEA. None of the isolates were able to induce infection in the absence of VEA. Non-type b isolates failed to produce disease in the mice models even at the highest inoculated dose (10⁸ cfu) and in the presence of VEA. BALB/c mice appeared suitable for evaluating the virulence of Hib strains, and 2% hemoglobin with 4% mucin an appropriate concentration for inducing infection in this animal model.

  7. [Real-time PCR detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae DNA in clinical specimens].

    PubMed

    Vacková, Z; Lžičařová, D; Stock, N K; Kozáková, J

    2015-10-01

    The study aim was to implement a molecular real-time polymerase chain reaction (PCR) assay recommended by the CDC (Centers for Disease Control and Prevention) for the detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in clinical (culture negative) specimens from patients with suspected invasive bacterial disease. Clinical specimens are referred to the National Reference Laboratory (NRL) for Meningococcal Infections, Unit for Airborne Bacterial Infections, Centre for Epidemiology and Microbiology, National Institute of Public Health from various regions of the Czech Republic. Clinical specimens are, in particular, cerebrospinal fluid, anti-coagulated blood or serum and, exceptionally, post-mortem specimens. The NRL has implemented molecular diagnosis of these bacterial pathogens involved in meningitis and sepsis from clinical specimens since 1999. The first diagnostic method was semi-nested PCR followed by electrophoretic analysis. In 2014, a molecular qualitative real-time PCR assay was implemented.

  8. Crystal Structure of Homoserine Transacetylase from Haemophilus Influenzae Reveals a New Family of alpha/beta-Hydrolases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mirza,I.; Nazi, I.; Korczynska, M.

    2005-01-01

    Homoserine transacetylase catalyzes one of the required steps in the biosynthesis of methionine in fungi and several bacteria. We have determined the crystal structure of homoserine transacetylase from Haemophilus influenzae to a resolution of 1.65 A. The structure identifies this enzyme to be a member of the alpha/beta-hydrolase structural superfamily. The active site of the enzyme is located near the end of a deep tunnel formed by the juxtaposition of two domains and incorporates a catalytic triad involving Ser143, His337, and Asp304. A structural basis is given for the observed double displacement kinetic mechanism of homoserine transacetylase. Furthermore, the propertiesmore » of the tunnel provide a rationale for how homoserine transacetylase catalyzes a transferase reaction vs. hydrolysis, despite extensive similarity in active site architecture to hydrolytic enzymes.« less

  9. Susceptibility of Haemophilus influenzae Isolates from Blood and Cerebrospinal Fluid to Ampicillin, Chloramphenicol, and Trimethoprim-Sulfamethoxazole

    PubMed Central

    McGowan, John E.; Terry, Pamela M.; Nahmias, Andre J.

    1976-01-01

    Susceptibility to ampicillin and chloramphenicol in vitro has been determined for Haemophilus influenzae strains isolated from blood and/or cerebrospinal fluid cultures of patients admitted to two Atlanta hospitals from 1 January 1974 to 31 March 1975. Since the appearance of ampicillin-resistant strains of this organism in early 1974, chloramphenicol has been used in these hospitals as initial therapy for severe infection due to H. influenzae. Strains from five of 94 patients were resistant to ampicillin (minimum inhibitory concentration [MIC] ≥ 12.5 μg/ml), but all strains were susceptible to chloramphenicol (MIC < 2 μg/ml). The first 35 strains studied, including three resistant to ampicillin, were also tested for in vitro susceptibility to trimethoprim-sulfamethoxazole; all were highly susceptible (MIC ≤ 0.0312 μg of trimethoprim and 0.625 μg of sulfamethoxazole per ml). PMID:1083198

  10. Haemophilus ducreyi Partially Activates Human Myeloid Dendritic Cells▿

    PubMed Central

    Banks, Keith E.; Humphreys, Tricia L.; Li, Wei; Katz, Barry P.; Wilkes, David S.; Spinola, Stanley M.

    2007-01-01

    Dendritic cells (DC) orchestrate innate and adaptive immune responses to bacteria. How Haemophilus ducreyi, which causes genital ulcers and regional lymphadenitis, interacts with DC is unknown. H. ducreyi evades uptake by polymorphonuclear leukocyte and macrophage-like cell lines by secreting LspA1 and LspA2. Many H. ducreyi strains express cytolethal distending toxin (CDT), and recombinant CDT causes apoptosis of DC in vitro. Here, we examined interactions between DC and H. ducreyi 35000HP, which produces LspA1, LspA2, and CDT. In human volunteers infected with 35000HP, the ratio of myeloid DC to plasmacytoid DC was 2.8:1 in lesions, compared to a ratio of 1:1 in peripheral blood. Using myeloid DC derived from monocytes as surrogates for lesional DC, we found that DC infected with 35000HP remained as viable as uninfected DC for up to 48 h. Gentamicin protection and confocal microscopy assays demonstrated that DC ingested and killed 35000HP, but killing was incomplete at 48 h. The expression of LspA1 and LspA2 did not inhibit the uptake of H. ducreyi, despite inactivating Src kinases. Infection of DC with live 35000HP caused less cell surface marker activation than infection with heat-killed 35000HP and lipopolysaccharide (LPS) and inhibited maturation by LPS. However, infection of DC with live bacteria caused the secretion of significantly higher levels of interleukin-6 and tumor necrosis factor alpha than infection with heat-killed bacteria and LPS. The survival of H. ducreyi in DC may provide a mechanism by which the organism traffics to lymph nodes. Partial activation of DC may abrogate the establishment of a full Th1 response and an environment that promotes phagocytosis. PMID:17923525

  11. Impact of vaccination against Haemophilus influenzae type b with and without a booster dose on meningitis in four South American countries.

    PubMed

    Garcia, Salvador; Lagos, Rosanna; Muñoz, Alma; Picón, Teresa; Rosa, Raquel; Alfonso, Adriana; Abriata, Graciela; Gentile, Angela; Romanin, Viviana; Regueira, Mabel; Chiavetta, Laura; Agudelo, Clara Inés; Castañeda, Elizabeth; De la Hoz, Fernando; Higuera, Ana Betty; Arce, Patricia; Cohen, Adam L; Verani, Jennifer; Zuber, Patrick; Gabastou, Jean-Marc; Pastor, Desiree; Flannery, Brendan; Andrus, Jon

    2012-01-05

    To inform World Health Organization recommendations regarding use of Haemophilus influenzae type b (Hib) vaccines in national immunization programs, a multi-country evaluation of trends in Hib meningitis incidence and prevalence of nasopharyngeal Hib carriage was conducted in four South American countries using either a primary, three-dose immunization schedule without a booster dose or with a booster dose in the second year of life. Surveillance data suggest that high coverage of Hib conjugate vaccine sustained low incidence of Hib meningitis and low prevalence of Hib carriage whether or not a booster dose was used. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Novel blaROB-1-Bearing Plasmid Conferring Resistance to β-Lactams in Haemophilus parasuis Isolates from Healthy Weaning Pigs

    PubMed Central

    Moleres, Javier; Santos-López, Alfonso; Lázaro, Isidro; Labairu, Javier; Prat, Cristina; Ardanuy, Carmen; González-Zorn, Bruno

    2015-01-01

    Haemophilus parasuis, the causative agent of Glässer's disease, is one of the early colonizers of the nasal mucosa of piglets. It is prevalent in swine herds, and lesions associated with disease are fibrinous polyserositis and bronchopneumonia. Antibiotics are commonly used in disease control, and resistance to several antibiotics has been described in H. parasuis. Prediction of H. parasuis virulence is currently limited by our scarce understanding of its pathogenicity. Some genes have been associated with H. parasuis virulence, such as lsgB and group 1 vtaA, while biofilm growth has been associated with nonvirulent strains. In this study, 86 H. parasuis nasal isolates from farms that had not had a case of disease for more than 10 years were obtained by sampling piglets at weaning. Isolates were studied by enterobacterial repetitive intergenic consensus PCR and determination of the presence of lsgB and group 1 vtaA, biofilm formation, inflammatory cell response, and resistance to antibiotics. As part of the diversity encountered, a novel 2,661-bp plasmid, named pJMA-1, bearing the blaROB-1 β-lactamase was detected in eight colonizing strains. pJMA-1 was shown to share a backbone with other small plasmids described in the Pasteurellaceae, to be 100% stable, and to have a lower biological cost than the previously described plasmid pB1000. pJMA-1 was also found in nine H. parasuis nasal strains from a separate collection, but it was not detected in isolates from the lesions of animals with Glässer's disease or in nontypeable Haemophilus influenzae isolates. Altogether, we show that commensal H. parasuis isolates represent a reservoir of β-lactam resistance genes which can be transferred to pathogens or other bacteria. PMID:25747001

  13. Haemophilus ducreyi Hfq contributes to virulence gene regulation as cells enter stationary phase.

    PubMed

    Gangaiah, Dharanesh; Labandeira-Rey, Maria; Zhang, Xinjun; Fortney, Kate R; Ellinger, Sheila; Zwickl, Beth; Baker, Beth; Liu, Yunlong; Janowicz, Diane M; Katz, Barry P; Brautigam, Chad A; Munson, Robert S; Hansen, Eric J; Spinola, Stanley M

    2014-02-11

    To adapt to stresses encountered in stationary phase, Gram-negative bacteria utilize the alternative sigma factor RpoS. However, some species lack RpoS; thus, it is unclear how stationary-phase adaptation is regulated in these organisms. Here we defined the growth-phase-dependent transcriptomes of Haemophilus ducreyi, which lacks an RpoS homolog. Compared to mid-log-phase organisms, cells harvested from the stationary phase upregulated genes encoding several virulence determinants and a homolog of hfq. Insertional inactivation of hfq altered the expression of ~16% of the H. ducreyi genes. Importantly, there were a significant overlap and an inverse correlation in the transcript levels of genes differentially expressed in the hfq inactivation mutant relative to its parent and the genes differentially expressed in stationary phase relative to mid-log phase in the parent. Inactivation of hfq downregulated genes in the flp-tad and lspB-lspA2 operons, which encode several virulence determinants. To comply with FDA guidelines for human inoculation experiments, an unmarked hfq deletion mutant was constructed and was fully attenuated for virulence in humans. Inactivation or deletion of hfq downregulated Flp1 and impaired the ability of H. ducreyi to form microcolonies, downregulated DsrA and rendered H. ducreyi serum susceptible, and downregulated LspB and LspA2, which allow H. ducreyi to resist phagocytosis. We propose that, in the absence of an RpoS homolog, Hfq serves as a major contributor of H. ducreyi stationary-phase and virulence gene regulation. The contribution of Hfq to stationary-phase gene regulation may have broad implications for other organisms that lack an RpoS homolog. Pathogenic bacteria encounter a wide range of stresses in their hosts, including nutrient limitation; the ability to sense and respond to such stresses is crucial for bacterial pathogens to successfully establish an infection. Gram-negative bacteria frequently utilize the alternative sigma

  14. Comparative Susceptibility of Haemophilus Species to Cefaclor, Cefamandole, and Five Other Cephalosporins and Ampicillin, Chloramphenicol, and Tetracycline

    PubMed Central

    Watanakunakorn, Chatrchai; Glotzbecker, Cheryl

    1979-01-01

    The minimal inhibitory concentration of cefaclor, cephalexin, cephradine, cefamandole, cephalothin, cephapirin, cefazolin, ampicillin, chloramphenicol, and tetracycline for inhibition of 198 freshly isolated clinical strains of Haemophilus species (23 H. influenzae type b, 157 H. influenzae non-type b, 14 H. parainfluenzae, and 4 H. aphrophilus) was determined simultaneously by a slightly modified WHO-ICS agar dilution method. Nine strains were resistant to ampicillin. There was no correlation between ampicillin resistance and minimal inhibitory concentration of other antibiotics. All strains were susceptible to chloramphenicol, and all except five were susceptible to tetracycline. Cefaclor was the most active oral cephalosporin, and cefamandole was the most active parenteral cephalosporin. Among the seven cephalosporins tested, cefamandole was the most effective compound. All but two strains were inhibited by cefamandole at 2 μg or less per ml. PMID:258112

  15. Intercellular adhesion and biocide resistance in nontypeable Haemophilus influenzae biofilms

    PubMed Central

    Izano, Era A.; Shah, Suhagi M.; Kaplan, Jeffrey B.

    2009-01-01

    Respiratory infections caused by nontypeable Haemophilus influenzae (NTHi) are a major medical problem. Evidence suggests that the ability to form biofilms on mucosal surfaces may play a role in NTHi pathogenesis. However, the factors that contribute to NTHi biofilm cohesion remain largely unknown. In this study we investigated the biofilm growth and detachment phenotypes of eight NTHi clinical strains in vitro. We found that the majority of strains produced biofilms within 6 hours when cultured statically in tubes. Biofilm formation was inhibited when culture medium was supplemented with proteinase K or DNase I. Both enzymes also caused significant detachment of pre-formed NTHi biofilms. These findings indicate that both proteinaceous adhesins and extracellular DNA contribute to NTHi biofilm cohesion. Treatment of NTHi biofilms cultured in centrifugal filter devices with DNase I, but not with proteinase K, caused a significant decrease in fluid convection through the biofilms. These results suggest that extracellular DNA is the major volumetric component of the NTHi biofilm matrix. Mechanical or enzymatic disruption of NTHi biofilms cultured in microtiter plates significantly increased their sensitivity to killing by SDS, cetylpyridinium chloride, chlorhexidine gluconate, povidone iodine and sodium hypochlorite. These findings indicate that biocide resistance in NTHi biofilms is mediated to a large part by the cohesive and protective properties of the biofilm matrix. Understanding the mechanisms of biofilm cohesion and biocide resistance in NTHi biofilms may lead to new methods for treating NTHi-associated infections. PMID:19490830

  16. A biphasic epigenetic switch controls immunoevasion, virulence and niche adaptation in non-typeable Haemophilus influenzae.

    PubMed

    Atack, John M; Srikhanta, Yogitha N; Fox, Kate L; Jurcisek, Joseph A; Brockman, Kenneth L; Clark, Tyson A; Boitano, Matthew; Power, Peter M; Jen, Freda E-C; McEwan, Alastair G; Grimmond, Sean M; Smith, Arnold L; Barenkamp, Stephen J; Korlach, Jonas; Bakaletz, Lauren O; Jennings, Michael P

    2015-07-28

    Non-typeable Haemophilus influenzae contains an N(6)-adenine DNA-methyltransferase (ModA) that is subject to phase-variable expression (random ON/OFF switching). Five modA alleles, modA2, modA4, modA5, modA9 and modA10, account for over two-thirds of clinical otitis media isolates surveyed. Here, we use single molecule, real-time (SMRT) methylome analysis to identify the DNA-recognition motifs for all five of these modA alleles. Phase variation of these alleles regulates multiple proteins including vaccine candidates, and key virulence phenotypes such as antibiotic resistance (modA2, modA5, modA10), biofilm formation (modA2) and immunoevasion (modA4). Analyses of a modA2 strain in the chinchilla model of otitis media show a clear selection for ON switching of modA2 in the middle ear. Our results indicate that a biphasic epigenetic switch can control bacterial virulence, immunoevasion and niche adaptation in an animal model system.

  17. Ampicillin resistance of invasive Haemophilus influenzae isolates in Germany 2009-2012.

    PubMed

    Lâm, Thiên-Trí; Claus, Heike; Elias, Johannes; Frosch, Matthias; Vogel, Ulrich

    2015-10-01

    In this retrospective study covering a four-year observation period (2009-2012) the prevalence of aminopenicillin resistance of invasive Haemophilus influenzae (Hi) in Germany was analyzed. The main resistance mechanism against aminopenicillins is conferred by β-lactamase production, which can be inhibited by clavulanate or sulbactam. Apart from that, β-lactamase negative ampicillin resistance (BLNAR) has been reported due to mutations in the penicillin-binding protein PBP3. The prevalence of BLNAR varies considerably in different countries. Representative data from Germany have not been reported. We analyzed 704 culture positive cases with bacteraemia or detection of Hi in cerebrospinal fluid; 82 isolates (11.6%) were phenotypically resistant to ampicillin. Among these isolates, 65 (79.3%) showed β-lactamase production, and 17 isolates (20.7%) were phenotypic BLNAR Hi. The proportion of ampicillin resistant isolates remained stable over the observation period. Analysis of the PBP3 sequences of 133 isolates with different susceptibility phenotypes including susceptible, BLNAR, and β-lactamase positive isolates, revealed a high genetic diversity. Previously described PBP3 mutations were associated to elevated MIC values, albeit not exclusively, since few highly susceptible strains were found to be positive for the mutations. Furthermore, since ampicillin susceptible strains with elevated MIC values frequently harboured these mutations, prediction of the resistance phenotype using ftsI sequencing appears to be impossible. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Overlapping and Complementary Oxidative Stress Defense Mechanisms in Nontypeable Haemophilus influenzae

    PubMed Central

    Baker, Beth D.; Munson, Robert S.

    2014-01-01

    The Gram-negative commensal bacterium nontypeable Haemophilus influenzae (NTHI) can cause respiratory tract diseases that include otitis media, sinusitis, exacerbations of chronic obstructive pulmonary disease, and bronchitis. During colonization and infection, NTHI withstands oxidative stress generated by reactive oxygen species produced endogenously, by the host, and by other copathogens and flora. These reactive oxygen species include superoxide, hydrogen peroxide (H2O2), and hydroxyl radicals, whose killing is amplified by iron via the Fenton reaction. We previously identified genes that encode proteins with putative roles in protection of the NTHI isolate strain 86-028NP against oxidative stress. These include catalase (HktE), peroxiredoxin/glutaredoxin (PgdX), and a ferritin-like protein (Dps). Strains were generated with mutations in hktE, pgdX, and dps. The hktE mutant and a pgdX hktE double mutant were more sensitive than the parent to killing by H2O2. Conversely, the pgdX mutant was more resistant to H2O2 due to increased catalase activity. Supporting the role of killing via the Fenton reaction, binding of iron by Dps significantly mitigated the effect of H2O2-mediated killing. NTHI thus utilizes several effectors to resist oxidative stress, and regulation of free iron is critical to this protection. These mechanisms will be important for successful colonization and infection by this opportunistic human pathogen. PMID:25368297

  19. [Optimized isolation and purification of non-typeable Haemophilus influenzae Haps protein].

    PubMed

    Li, Wan-yi; Kuang, Yu; Li, Ming-yuan; Yang, Yuan; Jiang, Zhong-hua; Yao, Feng; Chen, Chang-chun

    2007-12-01

    To optimize the isolation and purification conditions for Hap(s) protein of non-typeable Haemophilus influenzae. Hap(s) protein was purified by ammonium sulfate precipitation, dialysis desalting and Hitrap weak cation exchange columns of CM Sepharose Fast Flow. The condition of the elution was optimized for pH and ionic strength, the absorbance at 280 nm of the elution samples were detected, and the targeted protein band in the collected samples was observed by SDS-PAGE electrophoresis. The Hitrap ion exchange column was eluted with buffer 1, which resulted in a baseline distribution of absorbance at 280 nm. Buffer 2 elution of the column resulted in the presence of peak absorbance with trails, which was identified to be constituted by some low molecular weight bands by subsequent SDS-PAGE. In serial column elution with buffer 3 with different ionic strength, a peak absorbance was observed with the ionic strength of 100 mmol/L NaCl, and SDS-PAGE confirmed that the peak was generated by the target protein. No obvious peaks or bands in SDS-PAGE occurred with the other ionic strengths. The pH of the buffer only affect the elution of the irrelevant proteins rather than the Hap(s) protein, and elution with the buffer containing 100 mmol/L NaCl can be optimal for eluting the Hap(s) protein.

  20. Susceptibility of Haemophilus influenzae to chloramphenicol and eight beta-lactam antibiotics.

    PubMed Central

    Thirumoorthi, M C; Kobos, D M; Dajani, A S

    1981-01-01

    We examined the minimal inhibitory concentrations and minimal bactericidal concentrations of chloramphenicol, ampicillin, ticarcillin, cefamandole, cefazolin, cefoxitin, cefotaxime, ceforanide, and moxalactam for 100 isolates of Haemophilus influenzae, 25 of which produced beta-lactamase. Susceptibility was not influenced by the capsular characteristic of the organism. The mean minimal inhibitory concentrations of cefamandole, ticarcillin, and ampicillin for beta-lactamase-producing strains were 3-, 120-, and 400-fold higher than their respective mean minimal inhibitory concentrations for beta-lactamase-negative strains. No such difference was noted for the other antibiotics. We performed time-kill curve studies, using chloramphenicol, ampicillin, cefamandole, cefotaxime, and moxalactam with two concentrations of the antimicrobial agents (4 or 20 times the minimal inhibitory concentrations) and two inoculum sizes (10(4) or 10(6) colony-forming units per ml). The inoculum size had no appreciable effect on the rate of killing of beta-lactamase-negative strains. The rates at which beta-lactamase-producing strains were killed by chloramphenicol, cefotaxime, and moxalactam was not influenced by the inoculum size. Whereas cefamandole in high concentrations was able to kill at 10(6) colony-forming units/ml of inoculum, it had only a temporary inhibiting effect at low drug concentrations. Methicillin and the beta-lactamase inhibitor CP-45,899 were able to neutralize the inactivation of cefamandole by a large inoculum of beta-lactamase-producing H. influenzae. PMID:6974541

  1. Use of signature-tagged mutagenesis to identify virulence determinants in Haemophilus ducreyi responsible for ulcer formation.

    PubMed

    Yeung, Angela; Cameron, D William; Desjardins, Marc; Lee, B Craig

    2011-02-01

    Elucidating the molecular mechanisms responsible for chancroid, a genital ulcer disease caused by Haemophilus ducreyi, has been hampered in part by the relative genetic intractability of the organism. A whole genome screen using signature-tagged mutagenesis in the temperature-dependent rabbit model (TDRM) of H. ducreyi infection uncovered 26 mutants with a presumptive attenuated phenotype. Insertions in two previously recognized virulence determinants, hgbA and lspA1, validated this genome scanning technique. Database interrogation allowed assignment of 24 mutants to several functional classes, including transport, metabolism, DNA repair, stress response and gene regulation. The attenuated virulence for a 3 strain with a mutation in hicB was confirmed by individual infection in the TDRM. The results from this preliminary study indicate that this high throughput strategy will further the understanding of the pathogenesis of H. ducreyi infection. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. The Elimination of Haemophilus influenzae type b meningitis following conjugate vaccine introduction in Senegal.

    PubMed

    Cissé, Moussa Fafa; Breugelmans, J Gabrielle; Bâ, Mamadou; Diop, Mouhamed Boss; Faye, Papa Coumba; Mhlanga, Bekithemba; Mueller, Judith E; Koffi, David; Gessner, Bradford D

    2010-06-01

    Senegal introduced routine infant Haemophilus influenzae type b (Hib) conjugate vaccine during 2005. We evaluated acute bacterial meningitis surveillance data among children 0 to 59 months of age collected during January 2003 to September 2007 at the major pediatric referral hospital in the Dakar Region of Senegal. Hib vaccine effectiveness was assessed using a case-control design. A total of 1749 children with suspected bacterial meningitis were included in the current study of whom 142 (8%) had Hib identified. Among children less than age 1 year, the average annual Hib meningitis incidence decreased from 22 to 47 per 100,000 during 2003-2005 to 1.4 per 100,000 during 2007, while pneumococcal meningitis incidence remained stable. Before vaccine introduction, calculated incidences varied over 4-fold between districts within the Dakar Region for the years 2003 to 2005. Following use of Hib vaccine, pneumococcus has now become the most common etiology of pediatric acute bacterial meningitis in Dakar region. Senegal successfully implemented Hib conjugate vaccine into their routine infant immunization program with a resultant near elimination of Hib meningitis burden.

  3. Haemophilus parasuis serovar 5 Nagasaki strain adheres and invades PK-15 cells.

    PubMed

    Frandoloso, Rafael; Martínez-Martínez, Sonia; Gutiérrez-Martín, César B; Rodríguez-Ferri, Elías F

    2012-01-27

    Haemophilus parasuis is the agent responsible for causing Glässer's disease, which is characterized by fibrinous polyserositis, polyarthritis and meningitis in pigs. The purpose of this study was to investigate the in vitro ability of two H. parasuis serovars of different virulence (serovar 5, Nagasaki strain, highly virulent, belonging to serovar 5, and SW114 strain, nonvirulent, belonging to serovar 3) to adhere to and invade porcine kidney epithelial cells (PK-15 line). Nagasaki strain was able to attach at high levels from 60 to 180 min of incubation irrespective of the concentrations compared (10(7)-10(10)CFU), and a substantial increase of surface projections could be seen in PK-15 cells by scanning electron microscopy. This virulent strain was also able to invade effectively these epithelial cells, and the highest invasion capacity was reached at 180 min of infection. On the contrary, nonvirulent SW114 strain hardly adhered to PK-15 cells, and it did not invade these cells, thus suggesting that adherence and invasion of porcine kidney epithelial cells could be a virulence mechanism involved in the lesions caused by H. parasuis Nagasaki strain in this organ. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Resistance of non-typeable Haemophilus influenzae biofilms is independent of biofilm size.

    PubMed

    Reimche, Jennifer L; Kirse, Daniel J; Whigham, Amy S; Swords, W Edward

    2017-02-01

    The inflammatory middle ear disease known as otitis media can become chronic or recurrent in some cases due to failure of the antibiotic treatment to clear the bacterial etiological agent. Biofilms are known culprits of antibiotic-resistant infections; however, the mechanisms of resistance for non-typeable Haemophilus influenzae biofilms have not been completely elucidated. In this study, we utilized in vitro static biofilm assays to characterize clinical strain biofilms and addressed the hypothesis that biofilms with greater biomass and/or thickness would be more resistant to antimicrobial-mediated eradication than thinner and/or lower biomass biofilms. Consistent with previous studies, antibiotic concentrations required to eliminate biofilm bacteria tended to be drastically higher than concentrations required to kill planktonic bacteria. The size characterizations of the biofilms formed by the clinical isolates were compared to their minimum biofilm eradication concentrations for four antibiotics. This revealed no correlation between biofilm thickness or biomass and the ability to resist eradication by antibiotics. Therefore, we concluded that biofilm size does not play a role in antibiotic resistance, suggesting that reduction of antibiotic penetration may not be a significant mechanism for antibiotic resistance for this bacterial opportunist. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Haemophilus influenzae adherent to contact lenses associated with production of acute ocular inflammation.

    PubMed Central

    Sankaridurg, P R; Willcox, M D; Sharma, S; Gopinathan, U; Janakiraman, D; Hickson, S; Vuppala, N; Sweeney, D F; Rao, G N; Holden, B A

    1996-01-01

    Ten episodes of adverse responses to contact lens wear, including contact lens-induced acute red eye (CLARE), in which Haemophilus influenzae was isolated from contact lenses and/or from one of the external ocular sites at the time of the event, are described. All episodes occurred in patients wearing disposable hydrogel lenses on a 6-night extended-wear schedule. Two of the patients had recurrent episodes. H. influenzae was usually isolated in large numbers, and other bacteria or fungi colonizing the contact lens or the external ocular surface were usually present in low numbers. Those patients who were colonized with H. influenzae were more than 100 times as likely to have had a CLARE or infiltrative response than those subjects who were not colonized with this bacterium. H. influenzae colonization of the contact lens and eye may be subsequent to colonization of the nasopharynx because four of the seven patients presented with fever at the time of the event, with concurrent upper respiratory tract infection. Contact lens wearers should be made aware of the potential risk of CLARE associated with the wearing of contact lenses for extended periods during and subsequent to upper respiratory tract infection. PMID:8880493

  6. Lower airway colonization and inflammatory response in COPD: a focus on Haemophilus influenzae

    PubMed Central

    Finney, Lydia J; Ritchie, Andrew; Pollard, Elizabeth; Johnston, Sebastian L; Mallia, Patrick

    2014-01-01

    Bacterial infection of the lower respiratory tract in chronic obstructive pulmonary disease (COPD) patients is common both in stable patients and during acute exacerbations. The most frequent bacteria detected in COPD patients is Haemophilus influenzae, and it appears this organism is uniquely adapted to exploit immune deficiencies associated with COPD and to establish persistent infection in the lower respiratory tract. The presence of bacteria in the lower respiratory tract in stable COPD is termed colonization; however, there is increasing evidence that this is not an innocuous phenomenon but is associated with airway inflammation, increased symptoms, and increased risk for exacerbations. In this review, we discuss host immunity that offers protection against H. influenzae and how disturbance of these mechanisms, combined with pathogen mechanisms of immune evasion, promote persistence of H. influenzae in the lower airways in COPD. In addition, we examine the role of H. influenzae in COPD exacerbations, as well as interactions between H. influenzae and respiratory virus infections, and review the role of treatments and their effect on COPD outcomes. This review focuses predominantly on data derived from human studies but will refer to animal studies where they contribute to understanding the disease in humans. PMID:25342897

  7. Neglected infectious diseases in Aboriginal communities: Haemophilus influenzae serotype a and Helicobacter pylori.

    PubMed

    Ulanova, Marina; Tsang, Raymond; Altman, Eleonora

    2012-11-19

    This report describes proceedings of a workshop entitled "Neglected Infectious Diseases in Aboriginal Communities" which took place in Thunder Bay, Ontario, Canada, on October 12, 2011. This workshop was jointly organized by the National Research Council of Canada (NRC), the National Microbiology Laboratory (Public Health Agency of Canada) and Northern Ontario School of Medicine (NOSM) with participants from the Medical Sciences Division and Clinical Sciences Division of NOSM, NRC, National Microbiology Laboratory (NML), Public Health Laboratory (Thunder Bay), Thunder Bay District Health Unit, and Regional Health Survey at Chiefs of Ontario. The main purpose of the workshop was to summarize the current state of knowledge on two less publicized infectious disease agents afflicting Canadian Aboriginal communities: Haemophilus influenzae serotype a (Hia) and Helicobacter pylori. Another highlight of this workshop was the discussion on novel approaches for vaccination strategies in the control and prevention of such disease agents. In conclusion, a long-term collaborative research framework was established between NRC, NML and NOSM to develop carbohydrate-based vaccines against these pathogens that may benefit the health of Canadian Aboriginal peoples and other population groups at risk. Copyright © 2012. Published by Elsevier Ltd.. All rights reserved.

  8. Characterization and comparison of biofilm development by pathogenic and commensal isolates of Histophilus somni.

    PubMed

    Sandal, Indra; Hong, Wenzhou; Swords, W Edward; Inzana, Thomas J

    2007-11-01

    Histophilus somni (Haemophilus somnus) is an obligate inhabitant of the mucosal surfaces of bovines and sheep and an opportunistic pathogen responsible for respiratory disease, meningoencephalitis, myocarditis, arthritis, and other systemic infections. The identification of an exopolysaccharide produced by H. somni prompted us to evaluate whether the bacterium was capable of forming a biofilm. After growth in polyvinyl chloride wells a biofilm was formed by all strains examined, although most isolates from systemic sites produced more biofilm than commensal isolates from the prepuce. Biofilms of pneumonia isolate strain 2336 and commensal isolate strain 129Pt were grown in flow cells, followed by analysis by confocal laser scanning microscopy and scanning electron microscopy. Both strains formed biofilms that went through stages of attachment, growth, maturation, and detachment. However, strain 2336 produced a mature biofilm that consisted of thick, homogenous mound-shaped microcolonies encased in an amorphous extracellular matrix with profound water channels. In contrast, strain 129Pt formed a biofilm of cell clusters that were tower-shaped or distinct filamentous structures intertwined with each other by strands of extracellular matrix. The biofilm of strain 2336 had a mass and thickness that was 5- to 10-fold greater than that of strain 129Pt and covered 75 to 82% of the surface area, whereas the biofilm of strain 129Pt covered 35 to 40% of the surface area. Since H. somni is an obligate inhabitant of the bovine and ovine host, the formation of a biofilm may be crucial to its persistence in vivo, and our in vitro evidence suggests that formation of a more robust biofilm may provide a selective advantage for strains that cause systemic disease.

  9. Characterization and Comparison of Biofilm Development by Pathogenic and Commensal Isolates of Histophilus somni▿

    PubMed Central

    Sandal, Indra; Hong, Wenzhou; Swords, W. Edward; Inzana, Thomas J.

    2007-01-01

    Histophilus somni (Haemophilus somnus) is an obligate inhabitant of the mucosal surfaces of bovines and sheep and an opportunistic pathogen responsible for respiratory disease, meningoencephalitis, myocarditis, arthritis, and other systemic infections. The identification of an exopolysaccharide produced by H. somni prompted us to evaluate whether the bacterium was capable of forming a biofilm. After growth in polyvinyl chloride wells a biofilm was formed by all strains examined, although most isolates from systemic sites produced more biofilm than commensal isolates from the prepuce. Biofilms of pneumonia isolate strain 2336 and commensal isolate strain 129Pt were grown in flow cells, followed by analysis by confocal laser scanning microscopy and scanning electron microscopy. Both strains formed biofilms that went through stages of attachment, growth, maturation, and detachment. However, strain 2336 produced a mature biofilm that consisted of thick, homogenous mound-shaped microcolonies encased in an amorphous extracellular matrix with profound water channels. In contrast, strain 129Pt formed a biofilm of cell clusters that were tower-shaped or distinct filamentous structures intertwined with each other by strands of extracellular matrix. The biofilm of strain 2336 had a mass and thickness that was 5- to 10-fold greater than that of strain 129Pt and covered 75 to 82% of the surface area, whereas the biofilm of strain 129Pt covered 35 to 40% of the surface area. Since H. somni is an obligate inhabitant of the bovine and ovine host, the formation of a biofilm may be crucial to its persistence in vivo, and our in vitro evidence suggests that formation of a more robust biofilm may provide a selective advantage for strains that cause systemic disease. PMID:17644581

  10. The relationship between biofilm formations and capsule in Haemophilus influenzae.

    PubMed

    Qin, Liang; Kida, Yutaka; Ishiwada, Naruhiko; Ohkusu, Kiyofumi; Kaji, Chiharu; Sakai, Yoshiro; Watanabe, Kiwao; Furumoto, Akitsugu; Ichinose, Akitoyo; Watanabe, Hiroshi

    2014-03-01

    To evaluate the biofilm formation of non-typeable Haemophilus influenzae (NTHi) and H. influenzae type b (Hib) clinical isolates, we conducted the following study. Serotyping and polymerase chain reaction were performed to identify β-lactamase-negative ampicillin (ABPC)-susceptible (BLNAS), β-lactamase-negative ABPC-resistant (BLNAR), TEM-1 type β-lactamase-producing ABPC-resistant (BLPAR)-NTHi, and Hib. Biofilm formation was investigated by microtiter biofilm assay, as well as visually observation with a scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) in a continuous-flow chamber. As a result, totally 99 strains were investigated, and were classified into 4 groups which were 26 gBLNAS, 22 gBLNAR, 28 gBLPAR-NTHi and 23 Hib strains. The mean OD600 in the microtiter biofilm assay of gBLNAS, gBLNAR, gBLPAR-NTHi, and Hib strains were 0.57, 0.50, 0.34, and 0.08, respectively. NTHi strains were similar in terms of biofilm formations, which were observed by SEM and CLSM. Five Hib strains with the alternated type b cap loci showed significantly increased biofilm production than the other Hib strains. In conclusion, gBLNAS, gBLNAR, and gBLPAR-NTHi strains were more capable to produce biofilms compared to Hib strains. Our data suggested that resistant status may not be a key factor but capsule seemed to play an important role in H. influenzae biofilm formation. Copyright © 2013 Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  11. Capsule Typing of Haemophilus influenzae by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

    PubMed

    Månsson, Viktor; Gilsdorf, Janet R; Kahlmeter, Gunnar; Kilian, Mogens; Kroll, J Simon; Riesbeck, Kristian; Resman, Fredrik

    2018-03-01

    Encapsulated Haemophilus influenzae strains belong to type-specific genetic lineages. Reliable capsule typing requires PCR, but a more efficient method would be useful. We evaluated capsule typing by using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Isolates of all capsule types (a-f and nontypeable; n = 258) and isogenic capsule transformants (types a-d) were investigated. Principal component and biomarker analyses of mass spectra showed clustering, and mass peaks correlated with capsule type-specific genetic lineages. We used 31 selected isolates to construct a capsule typing database. Validation with the remaining isolates (n = 227) showed 100% sensitivity and 92.2% specificity for encapsulated strains (a-f; n = 61). Blinded validation of a supplemented database (n = 50) using clinical isolates (n = 126) showed 100% sensitivity and 100% specificity for encapsulated strains (b, e, and f; n = 28). MALDI-TOF mass spectrometry is an accurate method for capsule typing of H. influenzae.

  12. Fifteen novel immunoreactive proteins of Chinese virulent Haemophilus parasuis serotype 5 verified by an immunoproteomic assay.

    PubMed

    Yu, Yanfei; Wu, Guangyan; Zhai, Zhipeng; Yao, Huochun; Lu, Chengping; Zhang, Wei

    2015-01-01

    Haemophilus parasuis (H. parasuis) is associated with meningitis, polyserositis, polyarthritis and bacterial pneumonia. At present, its prevention and control is difficult because of the lack of suitable subunit vaccines. Nowadays, high-throughput methods, immunoproteomics, are available to screen for more vaccine candidates. A protein extraction method for H. parasuis and two-dimensional electrophoresis (2-DE) were optimized to provide high-resolution profiles covering pH 3 to 10. Twenty immunoreactive spots were excised from gels after strict comparison between 2-DE Western blot membranes and the relevant gels. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and MALDI-TOF-TOF-MS successfully identified 16 different proteins. Fifteen of them were reported as immunoreactive proteins in H. parasuis for the first time. In addition, recombinant HP5-7 (ABC transporter, periplasmic-binding protein) showed immunoreactivity both with hyperimmune rabbit serum and convalescent swine serum. Four recombinants of the 14 successfully expressed genes showed immunoreactivity with hyperimmune rabbit serum.

  13. Identification of another module involved in the horizontal transfer of the Haemophilus genomic island ICEHin1056.

    PubMed

    Juhas, Mario; Dimopoulou, Ioanna; Robinson, Esther; Elamin, Abdel; Harding, Rosalind; Hood, Derek; Crook, Derrick

    2013-09-01

    A significant part of horizontal gene transfer is facilitated by genomic islands. Haemophilus influenzae genomic island ICEHin1056 is an archetype of a genomic island that accounts for pandemic spread of antibiotics resistance. ICEHin1056 has modular structure and harbors modules involved in type IV secretion and integration. Previous studies have shown that ICEHin1056 encodes a functional type IV secretion system; however, other modules have not been characterized yet. Here we show that the module on the 5' extremity of ICEHin1056 consists of 15 genes that are well conserved in a number of related genomic islands. Furthermore by disrupting six genes of the investigated module of ICEHin1056 by site-specific mutagenesis we demonstrate that in addition to type IV secretion system module, the investigated module is also important for the successful conjugal transfer of ICEHin1056 from donor to recipient cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Incidence of Haemophilus influenzae type b meningitis in India.

    PubMed

    Minz, S; Balraj, V; Lalitha, M K; Murali, N; Cherian, T; Manoharan, G; Kadirvan, S; Joseph, A; Steinhoff, M C

    2008-07-01

    Vaccine policy depends on locally relevant disease burden estimates. The incidence of Haemophilus influenzae type b (Hib) disease is not well characterized in the South Asian region, home to 30 per cent of the world's children. There are limited data from prospective population incidence studies of Hib in Asia, and no data available from India. We therefore carried out this study to assess the burden of Hib meningitis in India. A prospective surveillance study was carried out during 1997 and 1999 in hospitals for cases of Hib meningitis from 5 administrative areas of an Indian district (Vellore, Tamil Nadu) with 56,153 children under 5 yr of age, over a 24 month period Ninety seven cases of possible meningitis (> 10 WBC/microl in CSF) were reported, an annual incidence of 86 per 100,000 (95%CI 69 to 109) in 0-4 yr old children, and 357 per 100,000 in 0-11 month infants. Eighteen had proven bacterial meningitis, an annual incidence of 15.9 per 100,000. Eight CSF had Hib by culture or antigen testing, an annual incidence of 7.1 per 100,000 (95%CI 3.1 to 14.0) in children 0-59 months. In infants 0-11 months of age, the incidence of Hib meningitis was 32 per 100,000 (95%CI 16 to 67) and in the 0-23 month group it was 19 (95%CI 8 to 37). Our data are the first minimal estimate of the incidence of Hib meningitis for Indian children. The observed incidence data are similar to European reports before Hib vaccine use, suggest substantial disease before 24 months of age, and provide data useful for policy regarding Hib immunization.

  15. Virulence, transmission, and heterologous protection of four isolates of Haemophilus parasuis.

    PubMed

    Brockmeier, Susan L; Loving, Crystal L; Mullins, Michael A; Register, Karen B; Nicholson, Tracy L; Wiseman, Barry S; Baker, Rodney B; Kehrli, Marcus E

    2013-09-01

    Haemophilus parasuis causes Glässer's disease, a syndrome of polyserositis, meningitis, and arthritis in swine. Previous studies with H. parasuis have revealed virulence disparity among isolates and inconsistent heterologous protection. In this study, virulence, direct transmission, and heterologous protection of 4 isolates of H. parasuis (SW114, 12939, MN-H, and 29755) were evaluated using a highly susceptible pig model. In an initial experiment, isolates 12939, MN-H, and 29755 caused Glässer's disease, while strain SW114 failed to cause any clinical signs of disease. One pig from each group challenged with MN-H or 29755 failed to develop clinical disease but was able to transmit H. parasuis to noninfected pigs, which subsequently developed Glässer's disease. Pigs colonized with SW114, 29755, or MN-H that were free of clinical disease were protected from a subsequent challenge with isolate 12939. In a following experiment, pigs vaccinated with strain SW114 given as either a bacterin intramuscularly or a live intranasal vaccine were protected from subsequent challenge with isolate 12939; however, some pigs given live SW114 developed arthritis. Overall these studies demonstrated that pigs infected with virulent isolates of H. parasuis can remain healthy and serve as reservoirs for transmission to naive pigs and that heterologous protection among H. parasuis isolates is possible. In addition, further attenuation of strain SW114 is necessary if it is to be used as a live vaccine.

  16. Molecular phylogenetic analysis of non-sexually transmitted strains of Haemophilus ducreyi.

    PubMed

    Gaston, Jordan R; Roberts, Sally A; Humphreys, Tricia L

    2015-01-01

    Haemophilus ducreyi, the etiologic agent of chancroid, has been previously reported to show genetic variance in several key virulence factors, placing strains of the bacterium into two genetically distinct classes. Recent studies done in yaws-endemic areas of the South Pacific have shown that H. ducreyi is also a major cause of cutaneous limb ulcers (CLU) that are not sexually transmitted. To genetically assess CLU strains relative to the previously described class I, class II phylogenetic hierarchy, we examined nucleotide sequence diversity at 11 H. ducreyi loci, including virulence and housekeeping genes, which encompass approximately 1% of the H. ducreyi genome. Sequences for all 11 loci indicated that strains collected from leg ulcers exhibit DNA sequences homologous to class I strains of H. ducreyi. However, sequences for 3 loci, including a hemoglobin receptor (hgbA), serum resistance protein (dsrA), and a collagen adhesin (ncaA) contained informative amounts of variation. Phylogenetic analyses suggest that these non-sexually transmitted strains of H. ducreyi comprise a sub-clonal population within class I strains of H. ducreyi. Molecular dating suggests that CLU strains are the most recently developed, having diverged approximately 0.355 million years ago, fourteen times more recently than the class I/class II divergence. The CLU strains' divergence falls after the divergence of humans from chimpanzees, making it the first known H. ducreyi divergence event directly influenced by the selective pressures accompanying human hosts.

  17. Simplified PCR for detection of Haemophilus ducreyi and diagnosis of chancroid.

    PubMed Central

    West, B; Wilson, S M; Changalucha, J; Patel, S; Mayaud, P; Ballard, R C; Mabey, D

    1995-01-01

    A simplified PCR was developed for detection of Haemophilus ducreyi in samples from chancroid patients. The strategy included a straightforward chloroform extraction sample preparation method, a one-tube nested PCR to minimize contamination risks, and a colorimetric method for detection of products. Primers were designed from published nucleotide sequences of the 16S rRNA gene of H. ducreyi, with longer outer primers for annealing at a higher temperature and shorter inner primers labelled with biotin and digoxigenin for binding with avidin and colorimetric detection. The PCR technique detected all 35 strains of H. ducreyi tested, from four different geographical regions, and was negative for other, related strains of bacteria and for the common contaminating bacteria tested. Of 25 samples from H. ducreyi culture-positive chancroid patients, 24 were PCR positive and 1 produced a weak reaction. Of 83 samples from clinical cases of chancroid in the Republic of South Africa, 69 were PCR positive. The sensitivity of PCR compared with that of clinical diagnosis was 83%. All 50 negative control samples were negative. Encouraging results were also obtained with a consecutive series of 25 genital ulcer patients in Tanzania, of whom 9 were PCR positive. The adaptations of this simplified PCR strategy, at the sensitivity and specificity levels obtained, mean it will be useful for detection of H. ducreyi in areas where the organism is endemic, particularly where testing by culture is difficult or impossible. PMID:7540625

  18. Plasmid mediated antimicrobial resistance in Ontario isolates of Actinobacillus (Haemophilus) pleuropneumoniae.

    PubMed Central

    Gilbride, K A; Rosendal, S; Brunton, J L

    1989-01-01

    The genetic basis of antimicrobial resistance in Ontario isolates of Actinobacillus (Haemophilus) pleuropneumoniae was studied. Two Ontario isolates of A. pleuropneumoniae were found to be resistant to sulfonamides (Su), streptomycin (Sm) and ampicillin (Amp). Resistance to Su and Sm was specified by a 2.3 megadalton (Mdal) plasmid which appeared to be identical to pVM104, which has been described in isolates of A. pleuropneumoniae from South Dakota. Southern hybridization showed that the 2.3 Mdal Su Sm plasmid was highly related to those Hinc II fragments of RSF1010 known to carry the Su Sm genes, but was unrelated to the remainder of this Salmonella resistance plasmid. Resistance to Su and Amp was specified by a 3.5 Mdal plasmid and appeared identical to pVM105 previously reported. The beta-lactamase enzyme had an isoelectric point of approximately 9.0. Southern hybridization showed no relationship to the TEM beta-lactamase. A third isolate of A. pleuropneumoniae was found to be resistant to chloramphenicol (Cm), Su and Sm by virtue of a 3.0 Mdal plasmid which specified a chloramphenicol acetyl transferase. We conclude that resistance to Su, Sm, Amp and Cm is mediated by small plasmids in A. pleuropneumoniae. Although the Su and Sm resistance determinants are highly related to those found in Enterobacteriaceae, the plasmids themselves and the beta-lactamase determinant are different. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:2914226

  19. Nontypeable Haemophilus influenzae Induces Sustained Lung Oxidative Stress and Protease Expression

    PubMed Central

    King, Paul T.; Sharma, Roleen; O’Sullivan, Kim; Selemidis, Stavros; Lim, Steven; Radhakrishna, Naghmeh; Lo, Camden; Prasad, Jyotika; Callaghan, Judy; McLaughlin, Peter; Farmer, Michael; Steinfort, Daniel; Jennings, Barton; Ngui, James; Broughton, Bradley R. S.; Thomas, Belinda; Essilfie, Ama-Tawiah; Hickey, Michael; Holmes, Peter W.; Hansbro, Philip; Bardin, Philip G.; Holdsworth, Stephen R.

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHi) is a prevalent bacterium found in a variety of chronic respiratory diseases. The role of this bacterium in the pathogenesis of lung inflammation is not well defined. In this study we examined the effect of NTHi on two important lung inflammatory processes 1), oxidative stress and 2), protease expression. Bronchoalveolar macrophages were obtained from 121 human subjects, blood neutrophils from 15 subjects, and human-lung fibroblast and epithelial cell lines from 16 subjects. Cells were stimulated with NTHi to measure the effect on reactive oxygen species (ROS) production and extracellular trap formation. We also measured the production of the oxidant, 3-nitrotyrosine (3-NT) in the lungs of mice infected with this bacterium. NTHi induced widespread production of 3-NT in mouse lungs. This bacterium induced significantly increased ROS production in human fibroblasts, epithelial cells, macrophages and neutrophils; with the highest levels in the phagocytic cells. In human macrophages NTHi caused a sustained, extracellular production of ROS that increased over time. The production of ROS was associated with the formation of macrophage extracellular trap-like structures which co-expressed the protease metalloproteinase-12. The formation of the macrophage extracellular trap-like structures was markedly inhibited by the addition of DNase. In this study we have demonstrated that NTHi induces lung oxidative stress with macrophage extracellular trap formation and associated protease expression. DNase inhibited the formation of extracellular traps. PMID:25793977

  20. Modelling the impact of vaccination on curtailing Haemophilus influenzae serotype 'a'.

    PubMed

    Konini, Angjelina; Moghadas, Seyed M

    2015-12-21

    Haemophilus influenzae serotype a (Hia) is a human-restricted bacterial pathogen transmitted via direct contacts with an infectious individual. Currently, there is no vaccine available for prevention of Hia, and the disease is treated with antibiotics upon diagnosis. With ongoing efforts for the development of an anti-Hia protein-polysaccharide conjugated vaccine, we sought to investigate the effect of vaccination on curtailing Hia infection. We present the first stochastic model of Hia transmission and control dynamics, and parameterize it using available estimates in the literature. Since both naturally acquired and vaccine-induced immunity wane with time, model simulations show three important results. First, vaccination of only newborns cannot eliminate the pathogen from the population, even when a booster program is implemented with a high coverage. Second, achieving and maintaining a sufficiently high level of herd immunity for pathogen elimination requires vaccination of susceptible individuals in addition to a high vaccination coverage of newborns. Third, for a low vaccination rate of susceptible individuals, a high coverage of booster dose may be needed to raise the level of herd immunity for Hia eradication. Our findings highlight the importance of vaccination and timely boosting of the individual׳s immunity within the expected duration of vaccine-induced protection against Hia. When an anti-Hia vaccine becomes available, enhanced surveillance of Hia incidence and herd immunity could help determine vaccination rates and timelines for booster doses necessary to eliminate Hia from affected populations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Chancroid in Sheffield. A report of 22 cases diagnosed by isolating Haemophilus ducreyi in a modified medium.

    PubMed Central

    Hafiz, S; Kinghorn, G R; McEntegart, M G

    1981-01-01

    The causative organism of chancroid, Haemophilus ducreyi, is generally considered to be very fastidious and its isolation, maintenance, and detailed study very demanding. In this study a modified medium was developed, which allowed the organism to be isolated more frequently than previously would have been expected. Twenty-two cases of chancroid were confirmed by the isolation of H ducreyi in 160 patients with genital ulceration examined over a one-year period. The cases were apparently unrelated, and in only five was there a history of recent sexual contact abroad. Concurrent infection with other sexually transmitted diseases was present in 18 (81.8%) patients, and in 14 (63.6%) both H ducreyi and herpes simplex virus were isolated form the same genital ulcers. Thus, these findings indicate that chancroid is underdiagnosed in England and that H ducreyi may frequently occur as a secondary invader of damaged genital skin and mucosa. PMID:6976815

  2. Epidemiological Features and Antibiotic Resistance Patterns of Haemophilus influenzae Originating from Respiratory Tract and Vaginal Specimens in Pediatric Patients.

    PubMed

    Li, Jian-Ping; Hua, Chun-Zhen; Sun, Li-Ying; Wang, Hong-Jiao; Chen, Zhi-Min; Shang, Shi-Qiang

    2017-12-01

    Haemophilus influenzae (H. influenzae) is a common pathogen of respiratory tract infections in children, however, as a possible cause of vulvovaginitis in prepubertal girls, its epidemiological features, antibiotic-resistance patterns, and treatment are seldom noted. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Specimens obtained from patients were inoculated on Haemophilus selective medium; and drug-sensitivities tests were determined using the disk diffusion method. A cefinase disk was used to detect β-lactamase. A total of 610 H. influenzae strains, 81.6% (498/610) from the respiratory tract and 18.0% (110/610) from the vagina, were identified in the Children's Hospital in 2015. The age of the children with respiratory tract strains were significantly younger than those with vaginal strains (P < .001). The H. influenzae isolation rate in May was the highest. The β-lactamase positive rate was 51.5% (314/610), and 52.5% (320/610) were resistant to ampicillin. The susceptibilities rates to cefuroxime, ampicillin/sulbactam, cefotaxime, clarithromycin, and sulfamethoxazole-trimethoprim were 72.1% (440/610), 95.9%, 96.4% (588/610), 81.8% (499/610), and 36.4% (222/610), respectively. Higher resistance to ampicillin, cefuroxime, clarithromycin, and sulfamethoxazole-trimethoprim were found in respiratory tract strains, compared with vaginal strains (P < .05). All of the patients with H. influenzae in the respiratory tract were cured with oral or intravenous β-lactam antibiotics. Of all patients with vaginal strains, 50% (55/110) were cured with topical ofloxacin gel, and 44.5% (49/110) were cured with oral β-lactam antibiotics. The drug-resistance rates of H. influenzae isolated from vagina were lower than those from the respiratory tract. Topical ofloxacin gel or oral β-lactam antibiotics are effective treatments to eliminate the H. influenza causing infection in the vagina. Copyright © 2017 North American Society for Pediatric and

  3. Experimental infection of human volunteers with Haemophilus ducreyi: fifteen years of clinical data and experience.

    PubMed

    Janowicz, Diane M; Ofner, Susan; Katz, Barry P; Spinola, Stanley M

    2009-06-01

    Haemophilus ducreyi causes chancroid, which facilitates transmission of human immunodeficiency virus type 1. To better understand the biology of H. ducreyi, we developed a human inoculation model. In the present article, we describe clinical outcomes for 267 volunteers who were infected with H. ducreyi. There was a relationship between papule formation and estimated delivered dose. The outcome (either pustule formation or resolution) of infected sites for a given subject was not independent; the most important determinants of pustule formation were sex and host effects. When 41 subjects were infected a second time, their outcomes segregated toward their initial outcome, confirming the host effect. Subjects with pustules developed local symptoms that required withdrawal from the study after a mean of 8.6 days. There were 191 volunteers who had tissue biopsy performed, 173 of whom were available for follow-up analysis; 28 (16.2%) of these developed hypertrophic scars, but the model was otherwise safe. Mutant-parent trials confirmed key features in H. ducreyi pathogenesis, and the model has provided an opportunity to study differential human susceptibility to a bacterial infection.

  4. The emerging Haemophilus influenzae serotype a infection and a potential vaccine: Implementation science in action

    PubMed Central

    Barreto, L; Cox, AD; Ulanova, M; Bruce, MG; Tsang, RSW

    2017-01-01

    Haemophilus influenzae serotype b (Hib) was a major cause of meningitis in children until Hib conjugate vaccine was introduced into the routine infant immunization program and Hib disease in children was almost eliminated. In Alaska, northern Canada and other countries with Indigenous peoples, H. influenzae serotype a (Hia) has emerged as a significant cause of pneumonia, meningitis and septic arthritis especially in children under 24 months of age. A joint government initiative between the Public Health Agency of Canada (PHAC) and the National Research Council of Canada (NRC) was carried out to assess whether an Hia vaccine could be developed for the common good. The initiative included strategic partnerships with clinician researchers in Thunder Bay, Ontario who provide health services to Indigenous people and the Artic Investigations Program (AIP) of the United States Centers for Disease Control and Prevention (CDC) in Alaska. This government initiated and funded research identified that the development of an Hia vaccine is possible and ongoing surveillance that includes strain characterization is essential to understand the potential spread of Hia in North America and around the world. PMID:29770070

  5. The emerging Haemophilus influenzae serotype a infection and a potential vaccine: Implementation science in action.

    PubMed

    Barreto, L; Cox, A D; Ulanova, M; Bruce, M G; Tsang, Rsw

    2017-05-04

    Haemophilus influenzae serotype b (Hib) was a major cause of meningitis in children until Hib conjugate vaccine was introduced into the routine infant immunization program and Hib disease in children was almost eliminated. In Alaska, northern Canada and other countries with Indigenous peoples, H. influenzae serotype a (Hia) has emerged as a significant cause of pneumonia, meningitis and septic arthritis especially in children under 24 months of age. A joint government initiative between the Public Health Agency of Canada (PHAC) and the National Research Council of Canada (NRC) was carried out to assess whether an Hia vaccine could be developed for the common good. The initiative included strategic partnerships with clinician researchers in Thunder Bay, Ontario who provide health services to Indigenous people and the Artic Investigations Program (AIP) of the United States Centers for Disease Control and Prevention (CDC) in Alaska. This government initiated and funded research identified that the development of an Hia vaccine is possible and ongoing surveillance that includes strain characterization is essential to understand the potential spread of Hia in North America and around the world.

  6. Introduction of Haemophilus influenzae type B conjugate vaccine into routine immunization in Ghana and its impact on bacterial meningitis in children younger than five years.

    PubMed

    Renner, Lorna Awo; Newman, Mercy J; Ahadzie, Lawson; Antwi-Agyei, Kwadwo Odei; Eshetu, Messeret

    2007-04-01

    This report shows the impact of a pentavalent vaccine that includes Haemophilus influenzae type b (Hib) conjugate vaccine on bacterial meningitis in children younger than 5 years in Ghana. A review of the first 3 years of a pediatric bacterial meningitis surveillance program, started in August 2001 in Accra, Ghana, was undertaken. There was a significant reduction, P = 0.042 and 0.017, in percentage of purulent meningitis in children younger than 1 year, comparing the first year when the vaccine was introduced, to the second and third years, respectively.

  7. Immunogenicity and thermal stability of a combined vaccine against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases.

    PubMed

    Saydam, Manolya; Burkin, Karena; Care, Rory; Rigsby, Peter; Bolgiano, Barbara; Mawas, Fatme

    2010-08-31

    The immunogenicity, structure and stability of a combined conjugate vaccine against Haemophilus influenzae type b and meningococcal serogroup C (Hib/MenC) were investigated. A rat model for immunogenicity showed that antibody responses to Hib and MenC in the combined vaccine were similar to or higher than those of individual conjugates given alone, or concomitantly at separate sites. At elevated temperatures, the combination vaccine was slightly more stable than a monovalent Hib-TT vaccine, with respect to molecular size, which could be attributed to differences in the formulations. Following 5 weeks incubation at 56 degrees C, there was some dissociation of high molecular weight conjugate without significant loss of saccharide integrity; however, this did not significantly affect the vaccine immunogenicity, demonstrating the stability of this lyophilized vaccine. (c) 2010 Elsevier Ltd. All rights reserved.

  8. Cost benefit analysis of Haemophilus influenzae type b vaccination programme in Israel.

    PubMed Central

    Ginsberg, G M; Kassis, I; Dagan, R

    1993-01-01

    STUDY OBJECTIVE--The recent availability of Haemophilus influenzae type b (HIB) conjugate vaccines prompted an examination of the costs and benefits of four and three dose HIB prevention programmes targeting all newborns in Israel. MEASUREMENTS AND MAIN RESULTS--A four dose programme would reduce the number of childhood (aged 0-13) HIB cases from 184.2 to 31.3 per year, yielding a benefit ($1.03 million) to cost ($3.55 million) ratio of just 0.29/l for health services only, based on a vaccine price of $7.74 per dose. When benefits resulting from a reduction in mild handicaps and severe neurological sequelae are included, the benefit ($4.48 million) to cost ratio rises to 1.26/l and it reaches 1.45/l when the $0.66 million indirect benefits of reduced work absences and mortality are also included. Break even vaccine costs are $2.24 when health service benefits only are considered and $11.21 when all the benefits are included. CONCLUSION--In the absence of other projects with higher benefit to cost ratios, Israel should start to provide a nationwide HIB vaccination programme since the monetary benefits to society of such a programme will exceed the costs to society. A barrier to implementation may occur, however, because the costs of the programme exceed the benefits to the health services alone. PMID:8120505

  9. Haemophilus influenzae type b (Hib) vaccine: an effective control strategy in India.

    PubMed

    Verma, Ramesh; Khanna, Pardeep; Chawla, Suraj; Bairwa, Mohan; Prinja, Shankar; Rajput, Meena

    2011-11-01

    Haemophilus influenzae type b (Hib) is an encapsulated, non-motile and non-spore-forming Gram-negative coccobacillus which causes severe pneumonia, meningitis and other life threatening illnesses. Hib disease affects almost exclusively (95%) children aged less than 5 years throughout the world. The mean age of onset is 6-24 months after which it declines gradually until age 5 years. The World Health Organization (WHO) estimates that Hib is responsible for 3 million cases of serious illnesses and approximately 386,000 deaths worldwide each year in children aged under 5 years. In the latest position paper on Hib vaccine, WHO recommended the inclusion of Hib conjugate vaccines in all routine infant immunization programs without waiting for local disease-burden data. The WHO and the Global Alliance for Vaccine Immunization (GAVI) have been working to expand supplies of Hib vaccine, reduce vaccine cost, and assist especially low-income countries with vaccine introduction. Hib vaccine is safe, highly effective and readily available in the market. Hib vaccine has been shown to be > 95% efficacious in diverse populations around the world. Globally, hundreds of millions of doses of Hib vaccine have been administered in the last 2 decades. More than 160 countries are using Hib vaccine in national immunization programmes and around 25 countries planning to introduce. Hib vaccination fits into the India's national immunization schedule.

  10. Spectrum and burden of severe Haemophilus influenzae type b diseases in Asia.

    PubMed Central

    Peltola, H.

    1999-01-01

    The validity of the commonly held view that Haemophilus influenzae type b (Hib) diseases are rare in Asia is challenged in this article by a thorough analysis of the data available, often in languages other than English. The entire spectrum of Hib disease, not only meningitis, was taken into account, and over 100 reports from 25 countries were explored. Hib was the leading agent among nontuberculous childhood meningitis cases in two-thirds of 48 studies from 22 countries. Data from six countries showed that all the classical manifestations of invasive Hib diseases are also found in Asia, except epiglottitis, which was nearly absent. In Hong Kong Special Administrative Region of China Hib disease is rare, but otherwise the incidences seemed not to deviate much from those in Europe until recently, around 25 per 100,000 for meningitis and at least 40 per 100,000 per year for the classical Hib manifestations combined at age 0-4 years. In total, more than 200,000 cases of Hib disease are estimated to occur annually in Asia. Because nonbacteraemic Hib pneumonia remains mostly undetected, the total burden is probably significantly greater. The issue will be fully elucidated only by prospective epidemiological and clinical studies, but awaiting them should not delay large-scale vaccinations against Hib throughout Asia. PMID:10612883

  11. Rapid and Accurate Diagnosis of Acute Pyogenic Meningitis Due to Streptococcus Pneumoniae, Haemophilus influenzae Type b and Neisseria meningitidis Using A Multiplex PCR Assay.

    PubMed

    Seth, Rajeev; Murthy, Peela Sree Ramchandra; Sistla, Sujatha; Subramanian, Mahadevan; Tamilarasu, Kadhiravan

    2017-09-01

    Acute bacterial meningitis is one of the major causes of morbidity and mortality in children and geriatric population, especially in developing countries. Methods of identification are standard culture and other phenotypic tests in many resource poor settings. To use molecular methods for the improvement of aetiological diagnosis of acute pyogenic meningitis in patients. CSF samples of 125 patients were included for the study. Gram staining and culture were performed according to standard procedures. Antigen was detected using commercial latex agglutination test kit. Multiplex PCR was performed using previously published primers and protocols. Fischer's exact test was used for finding association between presence of the disease and clinical/biochemical parameters, considering two tailed p<0.05 as statistically significant. Sensitivity, specificity, positive and negative predictive values were calculated using Graphpad QuicCalc software. A total of 39 cases (31.2%) were confirmed to be of acute pyogenic meningitis based on biochemical methods. Only 10/39 was positive for the three organisms tested. Multiplex PCR was able to detect one additional isolate each of Streptococcus pneumoniae and Haemophilus influenzae type b. When compared with multiplex PCR as the gold standard, culture and latex agglutination tests had same sensitivity (80%), specificity (100%), PPV (100%) and NPV (97.8%), whereas Gram stain had poor sensitivity (40%) and good specificity (95.6%). Detection rates were higher in multiplex PCR for the two organisms Streptococcus pneumoniae and Haemophilus influenzae type b. Multiplex PCR was more sensitive than culture or antigen detection, and employing this assay can significantly increase the speed and accuracy of identification of the pathogen.

  12. SAFETY OF A CRM197-CONJUGATED HAEMOPHILUS INFLUENZAE TYPE B VACCINE IN KOREAN CHILDREN.

    PubMed

    Song, Hyoyoung; Bock, Hans; Guadagno, Alana; Costantini, Marco; Baehner, Frank; Kim, Yeon Ho; Ahn, Seung In; Son, Ki Hyuk; Yim, Dong-Seok

    2015-07-01

    Haemophilus influenzae type b (Hib) is a major cause of meningitis and pneumonia with high morbidity and mortality rates in young children. The introduction of effective and well-tolerated conjugate Hib vaccines, has nearly eradicated this disease in many countries. We investigated the safety of the Hib PRP-CRM197 vaccine in a multi-center post-marketing surveillance (PMS) study. Korean children (N = 764) aged 1-33 months were enrolled when receiving a routine primary immunization or a booster vaccine with Hib PRP-CRM197 and solicited and unsolicited adverse events (AEs) were recorded using a diary card for 7 and 28 days after each vaccination, respectively. In this study, AEs were reported by 66% of subjects but were generally mild, with 42% of subjects reporting solicited AEs and 46% reporting unsolicited AEs. Among the unsolicited AEs, 98% were determined to be unrelated to the study vaccine. The studied Hib PRP-CRM197 vaccine was well tolerated by the study group and found to have a similar safety profile to that reported in other clinical studies. This vaccine is suitable for routine immunization against Hib disease among Korean children. AEs due to this vaccine will continue to be monitored.

  13. High rates of recombination in otitis media isolates of non-typeable Haemophilus influenzae✩

    PubMed Central

    Cody, Alison J.; Field, Dawn; Feil, Edward J.; Stringer, Suzanna; Deadman, Mary E.; Tsolaki, Anthony G.; Gratz, Brett; Bouchet, Valérie; Goldstein, Richard; Hood, Derek W.; Moxon, E. Richard

    2008-01-01

    Non-typeable (NT) or capsule-deficient, Haemophilus influenzae (Hi) is a common commensal of the upper respiratory tract of humans and can be pathogenic resulting in diseases such as otitis media, sinusitis and pneumonia. The lipopolysaccharide (LPS) of NTHi is a major virulence factor that displays substantial intra-strain and inter-strain variation of its oligosaccharide structures. To investigate the genetic basis of LPS variation we sequenced internal regions of each of seven genes required for the biosynthesis of either the inner or the outer core oligosaccharide structures. These sequences were obtained from 25 representative NTHi isolates from episodes of otitis media. We found abundant evidence of recombination among LPS genes of NTHi, a finding in marked contrast to previous analyses of biosynthetic genes for capsular polysaccharide, a well-documented virulence factor of Hi. We found mosaic sequences, linkage equilibrium between loci and a lack of congruence between gene trees. These high rates were not confined to LPS genes since evidence for similar amounts of recombination was also found in eight housekeeping genes in a subset of the same 25 isolates. These findings provide a population based foundation for a better understanding of the role of NTHi LPS as a virulence factor and its potential as a candidate vaccine. PMID:12797973

  14. Structural determinants of the interaction between the Haemophilus influenzae Hap autotransporter and fibronectin.

    PubMed

    Spahich, Nicole A; Kenjale, Roma; McCann, Jessica; Meng, Guoyu; Ohashi, Tomoo; Erickson, Harold P; St Geme, Joseph W

    2014-06-01

    Haemophilus influenzae is a Gram-negative cocco-bacillus that initiates infection by colonizing the upper respiratory tract. Hap is an H. influenzae serine protease autotransporter protein that mediates adherence, invasion and microcolony formation in assays with human epithelial cells and is presumed to facilitate the process of colonization. Additionally, Hap mediates adherence to fibronectin, laminin and collagen IV, extracellular matrix (ECM) proteins that are present in the respiratory tract and are probably important targets for H. influenzae colonization. The region of Hap responsible for adherence to ECM proteins has been localized to the C-terminal 511 aa of the Hap passenger domain (HapS). In this study, we characterized the structural determinants of the interaction between HapS and fibronectin. Using defined fibronectin fragments, we established that Hap interacts with the fibronectin repeat fragment called FNIII(1-2). Using site-directed mutagenesis, we found a series of motifs in the C-terminal region of HapS that contribute to the interaction with fibronectin. Most of these motifs are located on the F1 and F3 faces of the HapS structure, suggesting that the F1 and F3 faces may be responsible for the HapS-fibronectin interaction. © 2014 The Authors.

  15. Structural determinants of the interaction between the Haemophilus influenzae Hap autotransporter and fibronectin

    PubMed Central

    Spahich, Nicole A.; Kenjale, Roma; McCann, Jessica; Meng, Guoyu; Ohashi, Tomoo; Erickson, Harold P.

    2014-01-01

    Haemophilus influenzae is a Gram-negative cocco-bacillus that initiates infection by colonizing the upper respiratory tract. Hap is an H. influenzae serine protease autotransporter protein that mediates adherence, invasion and microcolony formation in assays with human epithelial cells and is presumed to facilitate the process of colonization. Additionally, Hap mediates adherence to fibronectin, laminin and collagen IV, extracellular matrix (ECM) proteins that are present in the respiratory tract and are probably important targets for H. influenzae colonization. The region of Hap responsible for adherence to ECM proteins has been localized to the C-terminal 511 aa of the Hap passenger domain (HapS). In this study, we characterized the structural determinants of the interaction between HapS and fibronectin. Using defined fibronectin fragments, we established that Hap interacts with the fibronectin repeat fragment called FNIII(1–2). Using site-directed mutagenesis, we found a series of motifs in the C-terminal region of HapS that contribute to the interaction with fibronectin. Most of these motifs are located on the F1 and F3 faces of the HapS structure, suggesting that the F1 and F3 faces may be responsible for the HapS–fibronectin interaction. PMID:24687948

  16. Immunologic memory in Haemophilus influenzae type b conjugate vaccine failure.

    PubMed

    McVernon, J; Johnson, P D R; Pollard, A J; Slack, M P E; Moxon, E R

    2003-05-01

    To compare the convalescent antibody response to invasive Haemophilus influenzae type b (Hib) disease between conjugate vaccine immunised and unimmunised children, to look for evidence of priming for immunologic memory. Unmatched case-control study in the UK and Eire 1992-2001 and Victoria, Australia 1988-1990. A total of 93 children were identified as having invasive Hib disease following three doses of conjugate vaccine in infancy through post licensure surveillance throughout the UK and Eire; 92 unvaccinated children admitted to an Australian paediatric hospital with invasive Hib disease were used as historical controls. Convalescent serum was taken for measurement of Hib antibody concentration, and clinical information relating to potential disease risk factors was collected. The geometric mean concentrations of convalescent Hib antibodies were compared between immunised and unimmunised children, using raw and adjusted data. Hib conjugate vaccine immunised children had higher serum Hib antibody responses to disease (geometric mean concentration (GMC) 10.81 microg/ml (95% CI 6.62 to 17.66) than unimmunised children (1.06 microg/ml (0.61 to 1.84)) (p < 0.0001). However, following adjustment for the significant confounding influences of age at presentation and timing of serum collection, a difference persisted only in children presenting with meningitis (vaccinated GMC 3.78 microg/ml (2.78 to 5.15); unvaccinated GMC 1.48 microg/ml (0.90 to 2.21); p = 0.003). Higher antibody responses to invasive Hib disease in vaccinated children with meningitis reflect priming for immunologic memory by the vaccine. Although a majority of children in the UK are protected from Hib disease by immunisation, the relative roles of immunologic memory and other immune mechanisms in conferring protection remain unclear.

  17. Molecular characterization and antibiotic susceptibility of Haemophilus influenzae clinical isolates.

    PubMed

    K L Ç, Hüseyin; Akyol, Selcan; Parkan, Õmür Mustafa; Dinç, Gõkçen; Sav, Hafize; Aydemir, Gonca

    2017-03-01

    Haemophilus influenzae can cause invasive and severe infections in both adults and children such as otitis media, sinusitis, pneumonia, meningitis and bacteremia. The emerging antibiotic resistance in recent years against ampicillin and several other antibiotics among strains of H. influenzae gives cause for serious concern. Here, we investigate ß-lactamase (BL) activity in clinical isolates of H. influenzae, profile their resistance to antibiotics, and characterize the clonal relationship of the isolates. Antibiotic susceptibilities of 92 clinical isolates of H. influenzae (March 2011-May 2012) were determined using the disk diffusion method according to the Clinical & Laboratory Standards Institute (CLSI), and BL activity was detected using the nitrocefin disk method. The Rep-PCR method was used to characterize clonality of the isolates. All strains were found to be susceptible to levofloxacin and cefotaxime. Four isolates out of 92 (4.3%) were found resistant to ampicillin, one isolate (1.1%) was resistant to amoxicillin/clavulanic acid, 21 isolates (22.8%) were resistant to trimethoprim-sulfamethoxazole (SXT), and three isolates (3.3%) showed BL activity. One strain was BL-negative but resistant to ampicillin. The three isolates with BL activity and four isolates with resistance to ampicillin did not have a clonal relationship. Three distinct clones [clone A (with subclones A1 and A2), clone B, and clone C] were identified among the SXT-resistant strains. Most of the H. influenzae isolates in this study were susceptible to the antibiotics while SXT resistance was relatively more prevalent, which suggests that significant obstacles in the therapeutic use of antibiotics against H. influenzae strains are not expected in our region.

  18. Antimicrobial activity of a novel bioengineered honey against non-typeable Haemophilus influenzae biofilms: an in vitro study.

    PubMed

    Newby, Rachel S; Dryden, Matthew; Allan, Raymond N; Salib, Rami J

    2018-06-01

    The opportunistic pathogen non-typeable Haemophilus influenzae (NTHi) plays an important role in many chronic respiratory diseases including otitis media, chronic rhinosinusitis, cystic fibrosis and chronic obstructive pulmonary disease. Biofilm formation has been implicated in NTHi colonisation, persistence of infection and recalcitrance towards antimicrobials. There is therefore a pressing need for the development of novel treatment strategies that are effective against NTHi biofilm-associated diseases. SurgihoneyRO is a honey-based product that has been bioengineered to enable the slow release of H 2 O 2 , a reactive oxygen species to which H. influenzae is susceptible. Treatment of established NTHi biofilms with SurgihoneyRO significantly reduced biofilm viability through enhanced H 2 O 2 production and was shown to be more effective than the conventional antibiotic co-amoxiclav. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  19. Streptococcus pneumoniae and Haemophilus influenzae type b carriage in Chinese children aged 12-18 months in Shanghai, China: a cross-sectional study.

    PubMed

    Hu, Jiayu; Sun, Xiaodong; Huang, Zhuoying; Wagner, Abram L; Carlson, Bradley; Yang, Jianping; Tang, Suwen; Li, Yunyi; Boulton, Matthew L; Yuan, Zhengan

    2016-04-14

    The bacteria Streptococcus pneumoniae (pneumococcus) and Haemophilus influenzae type b (Hib) are leading causes of childhood pneumonia and meningitis and are major contributors to worldwide mortality in children younger than 5 years of age. Asymptomatic nasopharyngeal carriage of pneumococcus and Hib was determined for healthy children in Shanghai in 2009. Children from 5 immunization clinics were enrolled in this study. Specimens from the nasopharynx were collected and cultured in Columbia and chocolate agar to identify pneumococcal and Hib carriage. Pneumococcal specimens were serotyped with the Neufeld test, and antibiotic resistance for pneumococcal and Hib specimens used the E-test method. Significance of risk factors for carriage was assessed through chi-square tests. Among 614 children, 16.6% had pneumococcal carriage and 8.0% Hib carriage. The predominant serotype of pneumococcus that was isolated was 19 F (52.9%); serotype coverage was 68.6% for both 7-valent pneumococcal conjugate vaccine (PCV) and PCV-10, and 82.3% for PCV-13. Household residency and father's education were both significantly related to pneumococcal and Hib carriage. The majority of S. pneumoniae isolates were sensitive to most antimicrobials but there were high levels of resistance to azithromycin (51.0 %) and erythromycin (51.0%). Haemophilus influenzae isolates were sensitive to almost all antimicrobials tested although 12.2% of isolates were resistant to ampicillin. The pneumococcal and Hib vaccines require payment, and the children with the highest burden of disease may not be receiving these vaccines. Moreover, the presence of high antibiotic susceptibility towards pneumococcus, and to a lesser extent towards Hib, underscores the need for preventive protection against these diseases. Public funding of pneumococcal and Hib vaccines would be one mechanism to increase uptake of these vaccines.

  20. Invasive disease caused by Haemophilus influenzae in Sweden 1997-2009; evidence of increasing incidence and clinical burden of non-type b strains.

    PubMed

    Resman, F; Ristovski, M; Ahl, J; Forsgren, A; Gilsdorf, J R; Jasir, A; Kaijser, B; Kronvall, G; Riesbeck, K

    2011-11-01

    Introduction of a conjugated vaccine against encapsulated Haemophilus influenzae type b (Hib) has led to a dramatic reduction of invasive Hib disease. However, an increasing incidence of invasive disease by H. influenzae non-type b has recently been reported. Non-type b strains have been suggested to be opportunists in an invasive context, but information on clinical consequences and related medical conditions is scarce. In this retrospective study, all H. influenzae isolates (n = 410) from blood and cerebrospinal fluid in three metropolitan Swedish regions between 1997 and 2009 from a population of approximately 3 million individuals were identified. All available isolates were serotyped by PCR (n = 250). We observed a statistically significant increase in the incidence of invasive H. influenzae disease, ascribed to non-typeable H. influenzae (NTHi) and encapsulated strains type f (Hif) in mainly individuals >60 years of age. The medical reports from a subset of 136 cases of invasive Haemophilus disease revealed that 48% of invasive NTHi cases and 59% of invasive Hif cases, respectively, met the criteria of severe sepsis or septic shock according to the ACCP/SCCM classification of sepsis grading. One-fifth of invasive NTHi cases and more than one-third of invasive Hif cases were admitted to intensive care units. Only 37% of patients with invasive non-type b disease had evidence of immunocompromise, of which conditions related to impaired humoral immunity was the most common. The clinical burden of invasive non-type b H. influenzae disease, measured as days of hospitalization/100 000 individuals at risk and year, increased significantly throughout the study period. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

  1. Susceptibilities of Haemophilus influenzae and Moraxella catarrhalis to ABT-773 Compared to Their Susceptibilities to 11 Other Agents

    PubMed Central

    Credito, Kim L.; Lin, Gengrong; Pankuch, Glenn A.; Bajaksouzian, Saralee; Jacobs, Michael R.; Appelbaum, Peter C.

    2001-01-01

    The activity of the ketolide ABT-773 against Haemophilus and Moraxella was compared to those of 11 other agents. Against 210 Haemophilus influenzae strains (39.0% β-lactamase positive), microbroth dilution tests showed that azithromycin and ABT-773 had the lowest MICs (0.5 to 4.0 and 1.0 to 8.0 μg/ml, respectively), followed by clarithromycin and roxithromycin (4.0 to >32.0 μg/ml). Of the β-lactams, ceftriaxone had the lowest MICs (≤0.004 to 0.016 μg/ml), followed by cefixime and cefpodoxime (0.008 to 0.125 and ≤0.125 to 0.25 μg/ml, respectively), amoxicillin-clavulanate (0.125 to 4.0 μg/ml), and cefuroxime (0.25 to 8.0 μg/ml). Amoxicillin was only active against β-lactamase-negative strains, and cefprozil had the highest MICs of all oral cephalosporins tested (0.5 to >32.0 μg/ml). Against 50 Moraxella catarrhalis strains, all of the compounds except amoxicillin and cefprozil were active. Time-kill studies against 10 H. influenzae strains showed that ABT-773, at two times the MIC, was bactericidal against 9 of 10 strains, with 99% killing of all strains at the MIC after 24 h; at 12 h, ABT-773 gave 90% killing of all strains at two times the MIC. At 3 and 6 h, killing by ABT-773 was slower, with 99.9% killing of four strains at two times the MIC after 6 h. Similar results were found for azithromycin, with slightly slower killing by erythromycin, clarithromycin, and roxithromycin, especially at earlier times. β-Lactams were bactericidal against 8 to 10 strains at two times the MIC after 24 h, with slower killing at earlier time periods. Most compounds gave good killing of five M. catarrhalis strains, with β-lactams killing more rapidly than other drugs. ABT-773 and azithromycin gave the longest postantibiotic effects (PAEs) of the ketolide-macrolide-azalide group tested (4.4 to >8.0 h), followed by clarithromycin, erythromycin, and roxithromycin. β-Lactam PAEs were similar and shorter than those of the ketolide-macrolide-azalide group for all strains

  2. Susceptibilities of Haemophilus influenzae and Moraxella catarrhalis to ABT-773 compared to their susceptibilities to 11 other agents.

    PubMed

    Credito, K L; Lin, G; Pankuch, G A; Bajaksouzian, S; Jacobs, M R; Appelbaum, P C

    2001-01-01

    The activity of the ketolide ABT-773 against Haemophilus and Moraxella was compared to those of 11 other agents. Against 210 Haemophilus influenzae strains (39.0% beta-lactamase positive), microbroth dilution tests showed that azithromycin and ABT-773 had the lowest MICs (0.5 to 4.0 and 1.0 to 8.0 microg/ml, respectively), followed by clarithromycin and roxithromycin (4.0 to >32.0 microg/ml). Of the beta-lactams, ceftriaxone had the lowest MICs (32.0 microg/ml). Against 50 Moraxella catarrhalis strains, all of the compounds except amoxicillin and cefprozil were active. Time-kill studies against 10 H. influenzae strains showed that ABT-773, at two times the MIC, was bactericidal against 9 of 10 strains, with 99% killing of all strains at the MIC after 24 h; at 12 h, ABT-773 gave 90% killing of all strains at two times the MIC. At 3 and 6 h, killing by ABT-773 was slower, with 99.9% killing of four strains at two times the MIC after 6 h. Similar results were found for azithromycin, with slightly slower killing by erythromycin, clarithromycin, and roxithromycin, especially at earlier times. beta-Lactams were bactericidal against 8 to 10 strains at two times the MIC after 24 h, with slower killing at earlier time periods. Most compounds gave good killing of five M. catarrhalis strains, with beta-lactams killing more rapidly than other drugs. ABT-773 and azithromycin gave the longest postantibiotic effects (PAEs) of the ketolide-macrolide-azalide group tested (4.4 to >8.0 h), followed by clarithromycin, erythromycin, and roxithromycin. beta-Lactam PAEs were similar and shorter than those of the ketolide

  3. Relationship between naturally occurring human mucosal and serum antibody to the capsular polysaccharide of Haemophilus influenzae type b.

    PubMed

    Pichichero, M E; Insel, R A

    1982-08-01

    The prevalence of natural mucosal antibody to the capsular polysaccharide (polyribosylribitolphosphate [PRP]) of Haemophilus influenzae type b in adults at multiple secretory sites and the relationship between natural serum and mucosal antibodies with respect to their amount and fine binding specificity were examined. All of 16 lactating women had antibody to PRP in serum and mammary samples; 11 of 14 studied had nasal antibody and 12 of 14 had salivary antibody. The amount of serum antibody to PRP in an individual positively correlated with the amount of mucosal antibody at each of the three secretory sites examined, and the antibody amount between certain secretions were also positively correlated. Antibody to PRP that is cross-reactive with Escherichia coli K100 or Streptococcus pneumoniae type 6 capsular polysaccharides was detected in the secretions of seven and one subjects, respectively, but the amount was not correlated with serum cross-reactive antibody.

  4. The Epidemiologic and Pharmacodynamic Cutoff Values of Tilmicosin against Haemophilus parasuis.

    PubMed

    Zhang, Peng; Hao, Haihong; Li, Jun; Ahmad, Ijaz; Cheng, Guyue; Chen, Dongmei; Tao, Yanfei; Huang, Lingli; Wang, Yulian; Dai, Menghong; Liu, Zhenli; Yuan, Zonghui

    2016-01-01

    The aim of this study was to establish antimicrobial susceptibility breakpoints for tilmicosin against Haemophilus parasuis, which is an important pathogen of respiratory tract infections. The minimum inhibitory concentrations (MICs) of 103 H. parasuis isolates were determined by the agar dilution method. The wild type (WT) distribution and epidemiologic cutoff value (ECV) were evaluated by statistical analysis. The new bronchoaveolar lavage was used to establish intrapulmonary pharmacokinetic (PK) model in swine. The pharmacokinetic (PK) parameters of tilmicosin, both in pulmonary epithelial lining fluid (PELF) and in plasma, were determined using high performance liquid chromatography method and WinNonlin software. The pharmacodynamic cutoff (COPD) was calculated using Monte Carlo simulation. Our results showed that 100% of WT isolates were covered when the ECV was set at 16 μg/mL. The tilmicosin had concentration-dependent activity against H. parasuis. The PK data indicated that tilmicosin concentrations in PELF was rapidly increased to high levels at 4 h and kept stable until 48 h after drug administration, while the tilmicosin concentration in plasma reached maximum levels at 4 h and continued to decrease during 4-72 h. Using Monte Carlo simulation, COPD was defined as 1 μg/mL. Conclusively, the ECV and COPD of tilmicosin against H. parasuis were established for the first time based on the MIC distribution and PK-PD analysis in the target tissue, respectively. These values are of great importance for detection of tilmicosin-resistant H. parasuis and for effective treatment of clinical intrapulmonary infection caused by H. parasuis.

  5. The Epidemiologic and Pharmacodynamic Cutoff Values of Tilmicosin against Haemophilus parasuis

    PubMed Central

    Zhang, Peng; Hao, Haihong; Li, Jun; Ahmad, Ijaz; Cheng, Guyue; Chen, Dongmei; Tao, Yanfei; Huang, Lingli; Wang, Yulian; Dai, Menghong; Liu, Zhenli; Yuan, Zonghui

    2016-01-01

    The aim of this study was to establish antimicrobial susceptibility breakpoints for tilmicosin against Haemophilus parasuis, which is an important pathogen of respiratory tract infections. The minimum inhibitory concentrations (MICs) of 103 H. parasuis isolates were determined by the agar dilution method. The wild type (WT) distribution and epidemiologic cutoff value (ECV) were evaluated by statistical analysis. The new bronchoaveolar lavage was used to establish intrapulmonary pharmacokinetic (PK) model in swine. The pharmacokinetic (PK) parameters of tilmicosin, both in pulmonary epithelial lining fluid (PELF) and in plasma, were determined using high performance liquid chromatography method and WinNonlin software. The pharmacodynamic cutoff (COPD) was calculated using Monte Carlo simulation. Our results showed that 100% of WT isolates were covered when the ECV was set at 16 μg/mL. The tilmicosin had concentration-dependent activity against H. parasuis. The PK data indicated that tilmicosin concentrations in PELF was rapidly increased to high levels at 4 h and kept stable until 48 h after drug administration, while the tilmicosin concentration in plasma reached maximum levels at 4 h and continued to decrease during 4–72 h. Using Monte Carlo simulation, COPD was defined as 1 μg/mL. Conclusively, the ECV and COPD of tilmicosin against H. parasuis were established for the first time based on the MIC distribution and PK-PD analysis in the target tissue, respectively. These values are of great importance for detection of tilmicosin-resistant H. parasuis and for effective treatment of clinical intrapulmonary infection caused by H. parasuis. PMID:27047487

  6. Effect of enrofloxacin on Haemophilus parasuis infection, disease and immune response.

    PubMed

    Macedo, Nubia; Cheeran, Maxim C J; Rovira, Albert; Holtcamp, Andrew; Torremorell, Montserrat

    2017-02-01

    Haemophilus parasuis, the causative agent of Glasser's disease, is a pathogen that colonizes the upper respiratory tract (URT) of pigs, invades the bloodstream and causes polyserositis. Because antimicrobials are highly effective against H. parasuis, we hypothesized that they could have a detrimental effect on the establishment of an immune response if given at the time of URT colonization. In this study, we characterized clinical outcomes and antibody and IFN-γ responses to H. parasuis in pigs treated with enrofloxacin before or after low dose inoculation with a pathogenic H. parasuis strain. Pigs that were only inoculated with the agent (EXP group) and pigs that were treated with enrofloxacin and then inoculated (ABT/EXP group) developed signs of disease starting at 4days post inoculation (DPI), presented a significant increase in serum IgG and were protected against a subsequent homologous challenge. In contrast, pigs treated with antibiotic after inoculation (EXP/ABT group) neither showed signs of disease nor seroconverted (IgG) after low dose inoculation. EXP/ABT pigs as well as naïve control pigs [enrofloxacin only (ABT) and challenge only (CHA)] were susceptible to challenge. Variable levels of antibodies in bronchioalveolar fluid and IFN-γ in peripheral blood mononuclear cells were observed after H. parasuis inoculation, but were not associated with protection. In summary, only pigs treated before low dose H. parasuis inoculation seroconverted and were protected against subsequent challenge. Results from this study can help determine timing of antimicrobial use and contribute to our current understanding of judicious antibiotic use. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Microbial genome count in cerebrospinal fluid compared with clinical characteristics in pneumococcal and Haemophilus influenzae type b meningitis in children.

    PubMed

    Roine, Irmeli; Saukkoriipi, Annika; Leinonen, Maija; Peltola, Heikki

    2009-01-01

    Cerebrospinal fluid genome counts were determined by quantitative real-time polymerase chain reaction from 121 children: 36 with Streptococcus pneumoniae and 85 with Haemophilus influenzae meningitis. To examine the interactions of genome count and to determine its prognostic importance, we projected the results against findings on admission and different outcomes. The genome count varied vastly in both meningitides ranging from 0 to 9,250,000/microL. The genome quantity was weakly associated with only some of the patient findings on admission. High counts predicted neurologic (odds ratio [OR]=1.36; 95% confidence interval [CI], 1.09-1.69; P=0.006 for 1 log increase) but not audiologic sequelae. They also predicted death in S .pneumoniae (OR=2.05; 95% CI, 1.08-3.87; P=0.03) but not in H. influenzae meningitis.

  8. The antibacterial activity and action mechanism of emodin from Polygonum cuspidatum against Haemophilus parasuis in vitro.

    PubMed

    Li, Li; Song, Xu; Yin, Zhongqiong; Jia, Renyong; Li, Zhengwen; Zhou, Xun; Zou, Yuanfeng; Li, Lixia; Yin, Lizi; Yue, Guizhou; Ye, Gang; Lv, Cheng; Shi, Wenjing; Fu, Yuping

    2016-01-01

    Haemophilus parasuis is the causative agent of Glässer's disease, which leads to serious economic loss to the swine industry. Although antibiotics are widely used to control infections, outbreaks of this disease repeatedly happen. In this study, emodin from Polygonum cuspidatum showed potent inhibitory effect against H. parasuis. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of emodin were 32 and 64μg/mL, respectively. The antibacterial kinetic curves indicated the antibacterial activity of emodin was in a concentration-dependent manner. Cell membrane permeability and flow cytometry assays proved that emodin could destroy cell membrane integrity and increase membrane permeability, and fluorescence spectra assay indicated emodin has influenced conformation of membrane protein. Under transmission electron microscopy, serious lesions of H. parasuis exposed to emodin (64μg/mL) were found, including irregular cell shape, plasmolysis, ruptured cell wall and membrane and cytoplasmic vacuolation. These results suggested that emodin could be used as candidate for treating Glässer's disease. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Reliability of Haemophilus influenzae biofilm measurement via static method, and determinants of in vitro biofilm production.

    PubMed

    Obaid, Najla A; Tristram, Stephen; Narkowicz, Christian K; Jacobson, Glenn A

    2016-12-01

    Information is lacking regarding the precision of microtitre plate (MTP) assays used to measure biofilm. This study investigated the precision of an MTP assay to measure biofilm production by nontypeable Haemophilus influenzae (NTHi) and the effects of frozen storage and inoculation technique on biofilm production. The density of bacterial final growth was determined by absorbance after 18-20 h incubation, and biofilm production was then measured by absorbance after crystal violet staining. Biofilm formation was categorised as high and low for each strain. For the high biofilm producing strains of NTHi, interday reproducibility of NTHi biofilm formation measured using the MTP assay was excellent and met the acceptance criteria, but higher variability was observed in low biofilm producers. Method of inoculum preparation was a determinant of biofilm formation with inoculum prepared directly from solid media showing increased biofilm production for at least one of the high producing strains. In general, storage of NTHi cultures at -80 °C for up to 48 weeks did not have any major effect on their ability to produce biofilm.

  10. Molecular cloning, sequencing, and expression of the outer membrane protein P2 gene of Haemophilus parasuis.

    PubMed

    Li, Peng; Bai, Juan; Li, Jun-xing; Zhang, Guo-long; Song, Yan-hua; Li, Yu-feng; Wang, Xian-wei; Jiang, Ping

    2012-10-01

    Haemophilus parasuis is the etiological agent of Glässer's disease characterized by fibrinous polyserositis, polyarthritis, and meningitis in young pigs. But it is difficult to develop universal serological diagnostic tools and effective vaccines against this disease because of the serovar diversity of the isolates. In this study, enterobacterial repetitive intergenic consensus-polymerase chain reaction, were performed to investigate the gene profile of 111 isolates of H. parasuis from China. And a specific common gene of H. parasuis was cloned and identified as the outer-membrane protein (OMP) P2 gene. Sequencing results of OMP P2 genes of 22 isolates showed that they had high homology and could be divided into 2 genetic types. Moreover, the OMPP2 protein was expressed in Escherichia coli expressing system. And the purified recombinant protein provided partial protection against H. parasuis infection in mice. It suggested the OMP P2 was an immunogenic protein and had great potential to serve as a vaccine and diagnostic antigen. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Immunoglobulin deficiency in patients with Streptococcus pneumoniae or Haemophilus influenzae invasive infections.

    PubMed

    Martinot, Martin; Oswald, Laetitia; Parisi, Elisabeth; Etienne, Elodie; Argy, Nicolas; Grawey, Isabelle; De Briel, Dominique; Zadeh, Mahsa Mohseni; Federici, Laure; Blaison, Gilles; Koebel, Christelle; Jaulhac, Benoit; Hansmann, Yves; Christmann, Daniel

    2014-02-01

    Immunoglobulin (Ig) deficiency is a well-known risk factor for Streptococcus pneumoniae or Haemophilus influenzae infections and noteworthy invasive diseases. However, the proportion of these deficiencies in cases of invasive disease is unknown. The objective of this study was to evaluate the rate of Ig deficiency in cases of invasive disease. A prospective study was conducted from January 2008 to October 2010 in two French hospitals. Measurement of Ig levels was carried out in patients hospitalized for invasive diseases. A total of 119 patients were enrolled in the study, with nine cases of H. influenzae and 110 cases of S. pneumoniae invasive disease. There were 18 cases of meningitis, 79 of invasive pneumonia, and 22 other invasive diseases. Forty-five patients (37.8%) had an Ig abnormality, 37 of whom had an Ig deficiency (20 IgG <6g/l, four isolated IgA <0.7g/l, and 13 isolated IgM <0.5g/l), while eight had an elevated monoclonal paraprotein. Nineteen of these 45 patients had a clearly defined Ig abnormality, with five primary deficiencies (three common variable immunodeficiencies and two complete IgA deficiencies) and 14 secondary deficiencies, mainly lymphoproliferative disorders. All these deficiencies were either not known or not substituted. Humoral deficiency is frequent in patients with S. pneumoniae or H. influenzae invasive disease and Ig dosage should be proposed systematically after such infections. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Recognition of Nucleoside Monophosphate Substrates by Haemophilus influenzae Class C Acid Phosphatase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Singh, Harkewal; Schuermann, Jonathan P.; Reilly, Thomas J.

    2010-12-08

    The e (P4) phosphatase from Haemophilus influenzae functions in a vestigial NAD{sup +} utilization pathway by dephosphorylating nicotinamide mononucleotide to nicotinamide riboside. P4 is also the prototype of class C acid phosphatases (CCAPs), which are nonspecific 5{prime},3{prime}-nucleotidases localized to the bacterial outer membrane. To understand substrate recognition by P4 and other class C phosphatases, we have determined the crystal structures of a substrate-trapping mutant P4 enzyme complexed with nicotinamide mononucleotide, 5{prime}-AMP, 3{prime}-AMP, and 2{prime}-AMP. The structures reveal an anchor-shaped substrate-binding cavity comprising a conserved hydrophobic box that clamps the nucleotide base, a buried phosphoryl binding site, and three solvent-filled pocketsmore » that contact the ribose and the hydrogen-bonding edge of the base. The span between the hydrophobic box and the phosphoryl site is optimal for recognizing nucleoside monophosphates, explaining the general preference for this class of substrate. The base makes no hydrogen bonds with the enzyme, consistent with an observed lack of base specificity. Two solvent-filled pockets flanking the ribose are key to the dual recognition of 5{prime}-nucleotides and 3{prime}-nucleotides. These pockets minimize the enzyme's direct interactions with the ribose and provide sufficient space to accommodate 5{prime} substrates in an anti conformation and 3{prime} substrates in a syn conformation. Finally, the structures suggest that class B acid phosphatases and CCAPs share a common strategy for nucleotide recognition.« less

  13. Immunologic memory in Haemophilus influenzae type b conjugate vaccine failure

    PubMed Central

    McVernon, J; Johnson, P; Pollard, A; Slack, M; Moxon, E

    2003-01-01

    Aims: To compare the convalescent antibody response to invasive Haemophilus influenzae type b (Hib) disease between conjugate vaccine immunised and unimmunised children, to look for evidence of priming for immunologic memory. Methods: Unmatched case-control study in the UK and Eire 1992–2001 and Victoria, Australia 1988–1990. A total of 93 children were identified as having invasive Hib disease following three doses of conjugate vaccine in infancy through post licensure surveillance throughout the UK and Eire; 92 unvaccinated children admitted to an Australian paediatric hospital with invasive Hib disease were used as historical controls. Convalescent serum was taken for measurement of Hib antibody concentration, and clinical information relating to potential disease risk factors was collected. The geometric mean concentrations of convalescent Hib antibodies were compared between immunised and unimmunised children, using raw and adjusted data. Results: Hib conjugate vaccine immunised children had higher serum Hib antibody responses to disease (geometric mean concentration (GMC) 10.81 µg/ml (95% CI 6.62 to 17.66) than unimmunised children (1.06 µg/ml (0.61 to 1.84)) (p < 0.0001). However, following adjustment for the significant confounding influences of age at presentation and timing of serum collection, a difference persisted only in children presenting with meningitis (vaccinated GMC 3.78 µg/ml (2.78 to 5.15); unvaccinated GMC 1.48 µg/ml (0.90 to 2.21); p = 0.003). Conclusions: Higher antibody responses to invasive Hib disease in vaccinated children with meningitis reflect priming for immunologic memory by the vaccine. Although a majority of children in the UK are protected from Hib disease by immunisation, the relative roles of immunologic memory and other immune mechanisms in conferring protection remain unclear. PMID:12716702

  14. Chemical composition and biological activities of a phenol-water extract from Haemophilus influenzae type a.

    PubMed Central

    Raichvarg, D; Brossard, C; Agneray, J

    1979-01-01

    Ribonucleic acid was removed from a phenol-water extract of Haemophilus influenzae type a by streptomycin sulfate. This preparation was called purified preparation or PP. It contained neutral sugars (glucose, galactose, mannose, pentose), glucosamine, amino acids, and fatty acids. Heptose and 2-keto-3-deoxyoctonic acid were not present. The biological properties and immunogenicity were compared with the activities of lipopolysaccharide of Escherichia coli or Salmonella typhimurium. Higher doses were necessary to obtain lethality in mice and Sanarelli and Shwartzman reactions with our preparations than were necessary with lipopolysaccharide. The Limulus test and pyrogen assay in rabbits gave the same results with purified preparation and lipopolysaccharide, but pyrogenicity of purified preparation was not destroyed by NaOH treatment. Purified preparation was not as immunogenic at low doeses for rabbits as lipopolysaccharide. The results were different from those obtained with lipopolysaccharide but similar to those known from peptidoglycan studies. The contamination of purified preparation with peptidoglycan was negligible and cannot explain the biological activities of purified preparation. We suggest that the phenol-water extract from H. influenzae is not a classical endotoxin, but rather an endotoxin-like substance. PMID:317593

  15. Genome sequencing of disease and carriage isolates of nontypeable Haemophilus influenzae identifies discrete population structure

    PubMed Central

    De Chiara, Matteo; Hood, Derek; Muzzi, Alessandro; Pickard, Derek J.; Perkins, Tim; Pizza, Mariagrazia; Dougan, Gordon; Rappuoli, Rino; Moxon, E. Richard; Soriani, Marco; Donati, Claudio

    2014-01-01

    One of the main hurdles for the development of an effective and broadly protective vaccine against nonencapsulated isolates of Haemophilus influenzae (NTHi) lies in the genetic diversity of the species, which renders extremely difficult the identification of cross-protective candidate antigens. To assess whether a population structure of NTHi could be defined, we performed genome sequencing of a collection of diverse clinical isolates representative of both carriage and disease and of the diversity of the natural population. Analysis of the distribution of polymorphic sites in the core genome and of the composition of the accessory genome defined distinct evolutionary clades and supported a predominantly clonal evolution of NTHi, with the majority of genetic information transmitted vertically within lineages. A correlation between the population structure and the presence of selected surface-associated proteins and lipooligosaccharide structure, known to contribute to virulence, was found. This high-resolution, genome-based population structure of NTHi provides the foundation to obtain a better understanding, of NTHi adaptation to the host as well as its commensal and virulence behavior, that could facilitate intervention strategies against disease caused by this important human pathogen. PMID:24706866

  16. Genome sequencing of disease and carriage isolates of nontypeable Haemophilus influenzae identifies discrete population structure.

    PubMed

    De Chiara, Matteo; Hood, Derek; Muzzi, Alessandro; Pickard, Derek J; Perkins, Tim; Pizza, Mariagrazia; Dougan, Gordon; Rappuoli, Rino; Moxon, E Richard; Soriani, Marco; Donati, Claudio

    2014-04-08

    One of the main hurdles for the development of an effective and broadly protective vaccine against nonencapsulated isolates of Haemophilus influenzae (NTHi) lies in the genetic diversity of the species, which renders extremely difficult the identification of cross-protective candidate antigens. To assess whether a population structure of NTHi could be defined, we performed genome sequencing of a collection of diverse clinical isolates representative of both carriage and disease and of the diversity of the natural population. Analysis of the distribution of polymorphic sites in the core genome and of the composition of the accessory genome defined distinct evolutionary clades and supported a predominantly clonal evolution of NTHi, with the majority of genetic information transmitted vertically within lineages. A correlation between the population structure and the presence of selected surface-associated proteins and lipooligosaccharide structure, known to contribute to virulence, was found. This high-resolution, genome-based population structure of NTHi provides the foundation to obtain a better understanding, of NTHi adaptation to the host as well as its commensal and virulence behavior, that could facilitate intervention strategies against disease caused by this important human pathogen.

  17. Insights on persistent airway infection by non-typeable Haemophilus influenzae in chronic obstructive pulmonary disease

    PubMed Central

    Ahearn, Christian P.; Gallo, Mary C.

    2017-01-01

    Abstract Non-typeable Haemophilus influenzae (NTHi) is the most common bacterial cause of infection of the lower airways in adults with chronic obstructive pulmonary disease (COPD). Infection of the COPD airways causes acute exacerbations, resulting in substantial morbidity and mortality. NTHi has evolved multiple mechanisms to establish infection in the hostile environment of the COPD airways, allowing the pathogen to persist in the airways for months to years. Persistent infection of the COPD airways contributes to chronic airway inflammation that increases symptoms and accelerates the progressive loss of pulmonary function, which is a hallmark of the disease. Persistence mechanisms of NTHi include the expression of multiple redundant adhesins that mediate binding to host cellular and extracellular matrix components. NTHi evades host immune recognition and clearance by invading host epithelial cells, forming biofilms, altering gene expression and displaying surface antigenic variation. NTHi also binds host serum factors that confer serum resistance. Here we discuss the burden of COPD and the role of NTHi infections in the course of the disease. We provide an overview of NTHi mechanisms of persistence that allow the pathogen to establish a niche in the hostile COPD airways. PMID:28449098

  18. Baicalin Inhibits Haemophilus Parasuis-Induced High-Mobility Group Box 1 Release during Inflammation.

    PubMed

    Fu, Shulin; Liu, Huashan; Chen, Xiao; Qiu, Yinsheng; Ye, Chun; Liu, Yu; Wu, Zhongyuan; Guo, Ling; Hou, Yongqing; Hu, Chien-An Andy

    2018-04-27

    Haemophilus parasuis ( H. parasuis ) can cause Glässer’s disease in pigs. However, the molecular mechanism of the inflammation response induced by H. parasuis remains unclear. The high-mobility group box 1 (HMGB1) protein is related to the pathogenesis of various infectious pathogens, but little is known about whether H. parasuis can induce the release of HMGB1 in piglet peripheral blood monocytes. Baicalin displays important anti-inflammatory and anti-microbial activities. In the present study, we investigated whether H. parasuis can trigger the secretion of HMGB1 in piglet peripheral blood monocytes and the anti-inflammatory effect of baicalin on the production of HMGB1 in peripheral blood monocytes induced by H. parasuis during the inflammation response. In addition, host cell responses stimulated by H. parasuis were determined with RNA-Seq. The RNA-Seq results showed that H. parasuis infection provokes the expression of cytokines and the activation of numerous pathways. In addition, baicalin significantly reduced the release of HMGB1 in peripheral blood monocytes induced by H. parasuis . Taken together, our study showed that H. parasuis can induce the release of HMGB1 and baicalin can inhibit HMGB1 secretion in an H. parasuis -induced peripheral blood monocytes model, which may provide a new strategy for preventing the inflammatory disorders induced by H. parasuis .

  19. Specific binding of Haemophilus influenzae to minor gangliosides of human respiratory epithelial cells.

    PubMed Central

    Fakih, M G; Murphy, T F; Pattoli, M A; Berenson, C S

    1997-01-01

    Gangliosides are sialylated glycosphingolipids that serve as receptors for various bacteria. To investigate endogenous gangliosides of human respiratory epithelial cells as potential receptors for Haemophilus influenzae, three strains, including nontypeable H. influenzae (NTHI) 1479, and isogenic fimbriated (f+) and nonfimbriated (f0) H. influenzae type b 770235, were 3H labeled and overlaid on two-dimensional thin-layer chromatography (TLC) plates containing either purified HEp-2 gangliosides or murine brain gangliosides. NTHI 1479 bound exclusively to two distinct minor ganglioside doublets, with mobilities near that of GM1. These minor gangliosides comprised only 14.2 and 9.4% of the total, respectively. NTHI 1479 also bound to a distinct ganglioside of human macrophages whose chromatographic mobilities closely resemble those of one of the NTHI-binding gangliosides of HEp-2 cells. H. influenzae type b 770235 f+ and f0 each bound to a different minor HEp-2 ganglioside doublet, with proportionately weaker affinity for a major ganglioside doublet. Remarkably, none of the three strains bound to any murine brain gangliosides. Moreover, when 80 to 90% of sialic acid residues were enzymatically removed from HEp-2 gangliosides, NTHI 1479 binding was proportionately impaired, compared with untreated controls. Our findings support a role for specific gangliosides of specific cells as receptors for H. influenzae strains. Our findings further demonstrate that individual minor gangliosides possess unique biological properties. PMID:9125549

  20. Antibacterial activity of Artemisia asiatica essential oil against some common respiratory infection causing bacterial strains and its mechanism of action in Haemophilus influenzae.

    PubMed

    Huang, Jiehui; Qian, Chao; Xu, Hongjie; Huang, Yanjie

    2018-01-01

    The main objective of the current study was to investigate the chemical composition of the essential oil of Artemisia asiatica together with investigating the antibacterial effects it exerts on several common respiratory infection causing bacteria including Haemophilus influenzae. Its mechanism of action was studied using various state-of-the-art assays like scanning electron microscopy, DNA, RNA and protein leakage assays, growth curve assays etc. The essential oil was extracted from the leaves of A. asiatica by supercritical CO 2 fluid extraction technology. Chemical composition of essential oils was analyzed by gas chromatography-mass-spectrometry (GC-MS). The antibacterial activity was evaluated against 6 bacteria by the paper disc diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) values of the essential oil were estimated by agar dilution method. The antibacterial mechanism was evaluated by growth curve, the integrity of cell membrane and scanning electronmicroscope (SEM). Gas chromatographic analysis of the A. asiatica essential oil led to the identification of 16 chemical constituents accounting for 97.2% of the total oil composition. The major components were found to be Piperitone, (z)-davanone, p-cymene and 1, 8-cineole. The essential oil showed maximum growth inhibition against Haemophilus influenzae with a zone of inhibition of 24.5 mm and MIC/MBC values of 1.9/4.5 mg/mL respectively. Bacteria treated with the essential oil led to a rapid decrease in the number of viable cells. On adding the essential oil of A. asiatica to the bacterial culture, the constituents of the bacterial cell got released into the medium and this cell constituent release increased with increasing doses of the essential oil. SEM showed that the bacterial cells treated with the essential oil showed damaged cell wall, deformed cell morphology and shrunken cells. Copyright © 2017. Published by Elsevier Ltd.

  1. Limited Interactions between Streptococcus Suis and Haemophilus Parasuis in In Vitro Co-Infection Studies

    PubMed Central

    Mathieu-Denoncourt, Annabelle; Letendre, Corinne; Auger, Jean-Philippe; Segura, Mariela; Aragon, Virginia; Lacouture, Sonia; Gottschalk, Marcelo

    2018-01-01

    Streptococcus suis and Haemophilus parasuis are normal inhabitants of the porcine upper respiratory tract but are also among the most frequent causes of disease in weaned piglets worldwide, causing inflammatory diseases such as septicemia, meningitis and pneumonia. Using an in vitro model of infection with tracheal epithelial cells or primary alveolar macrophages (PAMs), it was possible to determine the interaction between S. suis serotype 2 and H. parasuis strains with different level of virulence. Within H. parasuis strains, the low-virulence F9 strain showed higher adhesion levels to respiratory epithelial cells and greater association levels to PAMs than the high-virulence Nagasaki strain. Accordingly, the low-virulence F9 strain induced, in general, higher levels of pro-inflammatory cytokines than the virulent Nagasaki strain from both cell types. In general, S. suis adhesion levels to respiratory epithelial cells were similar to H. parasuis Nagasaki strain. Yet, S. suis strains induced a significantly lower level of pro-inflammatory cytokine expression from epithelial cells and PAMs than those observed with both H. parasuis strains. Finally, this study has shown that, overall and under the conditions used in the present study, S. suis and H. parasuis have limited in vitro interactions between them and use probably different host receptors, regardless to their level of virulence. PMID:29316613

  2. Comparative genome analysis identifies novel nucleic acid diagnostic targets for use in the specific detection of Haemophilus influenzae.

    PubMed

    Coughlan, Helena; Reddington, Kate; Tuite, Nina; Boo, Teck Wee; Cormican, Martin; Barrett, Louise; Smith, Terry J; Clancy, Eoin; Barry, Thomas

    2015-10-01

    Haemophilus influenzae is recognised as an important human pathogen associated with invasive infections, including bloodstream infection and meningitis. Currently used molecular-based diagnostic assays lack specificity in correctly detecting and identifying H. influenzae. As such, there is a need to develop novel diagnostic assays for the specific identification of H. influenzae. Whole genome comparative analysis was performed to identify putative diagnostic targets, which are unique in nucleotide sequence to H. influenzae. From this analysis, we identified 2H. influenzae putative diagnostic targets, phoB and pstA, for use in real-time PCR diagnostic assays. Real-time PCR diagnostic assays using these targets were designed and optimised to specifically detect and identify all 55H. influenzae strains tested. These novel rapid assays can be applied to the specific detection and identification of H. influenzae for use in epidemiological studies and could also enable improved monitoring of invasive disease caused by these bacteria. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Biofilm formation by virulent and non-virulent strains of Haemophilus parasuis.

    PubMed

    Bello-Ortí, Bernardo; Deslandes, Vincent; Tremblay, Yannick D N; Labrie, Josée; Howell, Kate J; Tucker, Alexander W; Maskell, Duncan J; Aragon, Virginia; Jacques, Mario

    2014-11-27

    Haemophilus parasuis is a commensal bacterium of the upper respiratory tract of healthy pigs. It is also the etiological agent of Glässer's disease, a systemic disease characterized by polyarthritis, fibrinous polyserositis and meningitis, which causes high morbidity and mortality in piglets. The aim of this study was to evaluate biofilm formation by well-characterized virulent and non-virulent strains of H. parasuis. We observed that non-virulent strains isolated from the nasal cavities of healthy pigs formed significantly (p < 0.05) more biofilms than virulent strains isolated from lesions of pigs with Glässer's disease. These differences were observed when biofilms were formed in microtiter plates under static conditions or formed in the presence of shear force in a drip-flow apparatus or a microfluidic system. Confocal laser scanning microscopy using different fluorescent probes on a representative subset of strains indicated that the biofilm matrix contains poly-N-acetylglucosamine, proteins and eDNA. The biofilm matrix was highly sensitive to degradation by proteinase K. Comparison of transcriptional profiles of biofilm and planktonic cells of the non-virulent H. parasuis F9 strain revealed a significant number of up-regulated membrane-related genes in biofilms, and genes previously identified in Actinobacillus pleuropneumoniae biofilms. Our data indicate that non-virulent strains of H. parasuis have the ability to form robust biofilms in contrast to virulent, systemic strains. Biofilm formation might therefore allow the non-virulent strains to colonize and persist in the upper respiratory tract of pigs. Conversely, the planktonic state of the virulent strains might allow them to disseminate within the host.

  4. Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

    PubMed Central

    Nelson, Kevin L.; Nguyen, Victoria; Burnham, Carey-Ann D.; Clarridge, Jill E.; Qin, Xuan; Smith, Arnold L.

    2013-01-01

    The incidence of invasive infections due to Haemophilus influenzae has decreased significantly in developed countries with high rates of vaccination against H. influenzae serotype b (Hib). This vaccine provides no protection against H. influenzae serotype f (Hif), typically associated with invasive infections in adults with chronic disease and/or immunodeficiency, and rarely in otherwise healthy adults and children. The specific properties of Hif associated with virulence remain largely uncharacterized. A panel of 26 Hif strains consisting of both invasive disease-associated and mucosal surface non-invasive disease-associated isolates was surveyed by DNA fingerprinting, biotyping and PCR detection of hmw1, hmw2, hsf, the hif fimbrial locus and the lipo-oligosaccharide (LOS) biosynthetic island, and assessment of β-lactamase expression and determination of resistance to the bactericidal activity of normal adult human serum. Repetitive sequence-based PCR fingerprinting differentiated the 26 strains into three clusters, with the majority of isolates (22/26, 84.6 %) clustered into a single indistinguishable group. Most isolates (24/26, 92.3 %) were of biotype I and two isolates produced β-lactamase with detection of a conjugative plasmid, and the isolates displayed a range of resistances to the bactericidal activity of human serum. All 26 isolates carried the adhesin hsf, 21 carried a partial hif fimbrial operon and 4 had the adhesin genes hmw1/2. A LOS biosynthetic island was detected in 20 isolates consisting of the genes lic2BC. It was concluded that Hif has many recognized virulence properties and comprises a relatively homogeneous group independent of the anatomical source from which it was isolated. PMID:23242639

  5. Quantitative fucK gene polymerase chain reaction on sputum and nasopharyngeal secretions to detect Haemophilus influenzae pneumonia.

    PubMed

    Abdeldaim, Guma M K; Strålin, Kristoffer; Olcén, Per; Blomberg, Jonas; Mölling, Paula; Herrmann, Björn

    2013-06-01

    A quantitative polymerase chain reaction (PCR) for the fucK gene was developed for specific detection of Haemophilus influenzae. The method was tested on sputum and nasopharyngeal aspirate (NPA) from 78 patients with community-acquired pneumonia (CAP). With a reference standard of sputum culture and/or serology against the patient's own nasopharyngeal isolate, H. influenzae etiology was detected in 20 patients. Compared with the reference standard, fucK PCR (using the detection limit 10(5) DNA copies/mL) on sputum and NPA showed a sensitivity of 95.0% (19/20) in both cases, and specificities of 87.9% (51/58) and 89.5% (52/58), respectively. In a receiver operating characteristic curve analysis, sputum fucK PCR was found to be significantly superior to sputum P6 PCR for detection of H. influenzae CAP. NPA fucK PCR was positive in 3 of 54 adult controls without respiratory symptoms. In conclusion, quantitative fucK real-time PCR provides a sensitive and specific identification of H. influenzae in respiratory secretions. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Inactivation of the Haemophilus ducreyi luxS gene affects the virulence of this pathogen in human subjects.

    PubMed

    Labandeira-Rey, Maria; Janowicz, Diane M; Blick, Robert J; Fortney, Kate R; Zwickl, Beth; Katz, Barry P; Spinola, Stanley M; Hansen, Eric J

    2009-08-01

    Haemophilus ducreyi 35000HP contains a homologue of the luxS gene, which encodes an enzyme that synthesizes autoinducer 2 (AI-2) in other gram-negative bacteria. H. ducreyi 35000HP produced AI-2 that functioned in a Vibrio harveyi-based reporter system. A H. ducreyi luxS mutant was constructed by insertional inactivation of the luxS gene and lost the ability to produce AI-2. Provision of the H. ducreyi luxS gene in trans partially restored AI-2 production by the mutant. The luxS mutant was compared with its parent for virulence in the human challenge model of experimental chancroid. The pustule-formation rate in 5 volunteers was 93.3% (95% confidence interval, 81.7%-99.9%) at 15 parent sites and 60.0% (95% confidence interval, 48.3%-71.7%) at 15 mutant sites (1-tailed P < .001). Thus, the luxS mutant was partially attenuated for virulence. This is the first report of AI-2 production contributing to the pathogenesis of a genital ulcer disease.

  7. Haemophilus parasuis encodes two functional cytolethal distending toxins: CdtC contains an atypical cholesterol recognition/interaction region.

    PubMed

    Zhou, Mingguang; Zhang, Qiang; Zhao, Jianping; Jin, Meilin

    2012-01-01

    Haemophilus parasuis is the causative agent of Glässer's disease of pigs, a disease associated with fibrinous polyserositis, polyarthritis and meningitis. We report here H. parasuis encodes two copies of cytolethal distending toxins (Cdts), which these two Cdts showed the uniform toxin activity in vitro. We demonstrate that three Cdt peptides can form an active tripartite holotoxin that exhibits maximum cellular toxicity, and CdtA and CdtB form a more active toxin than CdtB and CdtC. Moreover, the cellular toxicity is associated with the binding of Cdt subunits to cells. Further analysis indicates that CdtC subunit contains an atypical cholesterol recognition/interaction amino acid consensus (CRAC) region. The mutation of CRAC site resulted in decreased cell toxicity. Finally, western blot analysis show all the 15 H. parasuis reference strains and 109 clinical isolates expressed CdtB subunit, indicating that Cdt is a conservative putative virulence factor for H. parasuis. This is the first report of the molecular and cellular basis of Cdt host interactions in H. parasuis.

  8. A cohort study of developmental polychlorinated biphenyl (PCB) exposure in relation to post-vaccination antibody response at 6-months of age

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jusko, Todd A., E-mail: juskota@niehs.nih.gov; Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA; De Roos, Anneclaire J.

    2010-05-15

    Background: Extensive experimental data in animals indicate that exposure to polychlorinated biphenyls (PCBs) during pregnancy leads to changes in offspring immune function during the postnatal period. Whether developmental PCB exposure influences immunologic development in humans has received little study. Methods: The study population was 384 mother-infant pairs recruited from two districts of eastern Slovakia for whom prospectively collected maternal, cord, and 6-month infant blood specimens were available. Several PCB congeners were measured in maternal, cord, and 6-month infant sera by high-resolution gas chromatography with electron capture detection. Concentrations of IgG-specific anti-haemophilus influenzae type b, tetanus toxoid, and diphtheria toxoid weremore » assayed in 6-month infant sera using ELISA methods. Multiple linear regression was used to estimate the relation between maternal, cord, and 6-month infant PCB concentrations and the antibody concentrations evaluated at 6-months of age. Results: Overall, there was little evidence of an association between infant antibody concentrations and PCB measures during the pre- and early postnatal period. In addition, our results did not show specificity in terms of associations limited to a particular developmental period (e.g. pre- vs. postnatal), a particular antibody, or a particular PCB congener. Conclusions: At the PCB concentrations measured in this cohort, which are high relative to most human populations today, we did not detect an association between maternal or early postnatal PCB exposure and specific antibody responses at 6-months of age.« less

  9. Effects of the 10-Valent Pneumococcal Nontypeable Haemophilus influenzae Protein D–Conjugate Vaccine on Nasopharyngeal Bacterial Colonization in Young Children: A Randomized Controlled Trial

    PubMed Central

    van den Bergh, Menno R.; Spijkerman, Judith; Swinnen, Kristien M.; François, Nancy A.; Pascal, Thierry G.; Borys, Dorota; Schuerman, Lode; IJzerman, Ed P. F.; Bruin, Jacob P.; van der Ende, Arie; Veenhoven, Reinier H.; Sanders, Elisabeth A. M.

    2013-01-01

    Background. This study evaluated the effects of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D–conjugate vaccine (PHiD-CV) on nasopharyngeal bacterial colonization compared with the 7-valent pneumococcal conjugate vaccine (7vCRM) in young children. Methods. A randomized controlled trial in the Netherlands, initiated 2 years after 7vCRM introduction, was conducted between 1 April 2008 and 1 December 2010. Infants (N = 780) received either PHiD-CV or 7vCRM (2:1) at 2, 3, 4, and 11–13 months of age. Nasopharyngeal samples taken at 5, 11, 14, 18, and 24 months of age were cultured to detect Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Staphylococcus aureus. Polymerase chain reaction assays quantified H. influenzae and S. pneumoniae and confirmed H. influenzae as nontypeable (NTHi). Primary outcome measure was vaccine efficacy (VE) against NTHi colonization. Results. In both groups, NTHi colonization increased with age from 33% in 5-month-olds to 65% in 24-month-olds. Three months postbooster, VE against colonization was 0.5% (95% confidence interval [CI], −21.8% to 18.4%) and VE against acquisition 10.9% (95% CI, −31.3% to 38.9%). At each sampling moment, no differences between groups in either NTHi prevalence or H. influenzae density were detected. Streptococcus pneumoniae (range, 39%–57%), M. catarrhalis (range, 63%­–69%), and S. aureus (range, 9%–30%) colonization patterns were similar between groups. Conclusions. PHiD-CV had no differential effect on nasopharyngeal NTHi colonization or H. influenzae density in healthy Dutch children up to 2 years of age, implying that herd effects for NTHi are not to be expected. Other bacterial colonization patterns were also similar. Clinical Trials Registration NCT00652951. PMID:23118268

  10. Prevalence of, Antibody Response to, and Immunity Induced by Haemophilus ducreyi Hemolysin

    PubMed Central

    Dutro, Susan M.; Wood, Gwendolyn E.; Totten, Patricia A.

    1999-01-01

    Haemophilus ducreyi, the etiologic agent of chancroid, a genital ulcer disease, produces a cell-associated hemolysin whose role in virulence is not well defined. Hemolysin is encoded by two genes, hhdA and hhdB, which, based on their homology to Serratia marcescens shlA and shlB genes, are believed to encode the hemolysin structural protein and a protein required for secretion and modification of this protein, respectively. In this study, we determined the prevalence and expression of the hemolysin genes in 90 H. ducreyi isolates obtained from diverse geographic locations from 1952 to 1996 and found that all strains contained DNA homologous to the hhdB and hhdA genes. In addition, all strains expressed a hemolytic activity. We also determined that hemolysin is expressed in vivo and is immunogenic, as indicated by the induction of antibodies to hemolysin in both the primate and rabbit disease models as well as in human patients with naturally acquired chancroid. Wild-type strain 35000 and isogenic hemolysin-negative mutants showed no difference in lesion development in the temperature-dependent rabbit model. However, immunization of rabbits with the purified hemolysin protein reduced the recovery of wild-type H. ducreyi, but not hemolysin-negative mutants, from lesions. Our study indicates that hemolysin is a possible candidate for vaccine development due to its immunogenicity, expression in vitro and in vivo by most, if not all, strains, and the effect of immunization on reducing the recovery of viable H. ducreyi in experimental disease in rabbits. PMID:10377108

  11. Preparation, characterization, and immunogenicity of Haemophilus influenzae type b polysaccharide-protein conjugates

    PubMed Central

    1980-01-01

    A method is presented for covalently bonding Haemophilus influenzae type b capsular polysaccharide (HIB Ps) to several proteins. The method is efficient and relies upon the use of adipic dihydrazide as a spacer between the capsular polysaccharide and the carrier protein. In contrast to the poor immunogenicity of the purified HIB Ps in mice and rabbits, the HIB Ps-protein conjugates induced serum anti-type b antibodies having bactericidal activity at levels shown to be protective in humans when low doses were injected subcutaneously in a saline solution. The antibody response in mice was related to the dose of the conjugates, increased with the number of injections, and could be primed by the previous injection of the carrier protein. The HIB Ps- protein conjugates were immunogenic in three different mouse strains. The importance of the carrier molecule for the enhanced immunogenicity of the HIB Ps-protein conjugates was shown by the failure of HIB Ps hybrids prepared with either the homologous polysaccharide or pneumococcus type 3 polysaccharide to induce antibodie in mice. Rabbits injected with the HIB Ps-protein conjugates emulsified in Freund's adjuvant produced high levels of serum anti-type b antibodies which induced a bactericidal effect upon H. influenzae type b organisms. It is proposed that the HIB Ps component of the polysaccharide protein conjugates has been converted to a thymic-dependent immunogen. This method may be used to prepare protein-polysaccharide conjugates with HIB Ps and other polysaccharides to be considered for human use. PMID:6967514

  12. Human milk lactoferrin inactivates two putative colonization factors expressed by Haemophilus influenzae.

    PubMed

    Qiu, J; Hendrixson, D R; Baker, E N; Murphy, T F; St Geme, J W; Plaut, A G

    1998-10-13

    Haemophilus influenzae is a major cause of otitis media and other respiratory tract disease in children. The pathogenesis of disease begins with colonization of the upper respiratory mucosa, a process that involves evasion of local immune mechanisms and adherence to epithelial cells. Several studies have demonstrated that human milk is protective against H. influenzae colonization and disease. In the present study, we examined the effect of human milk on the H. influenzae IgA1 protease and Hap adhesin, two autotransported proteins that are presumed to facilitate colonization. Our results demonstrated that human milk lactoferrin efficiently extracted the IgA1 protease preprotein from the bacterial outer membrane. In addition, lactoferrin specifically degraded the Hap adhesin and abolished Hap-mediated adherence. Extraction of IgA1 protease and degradation of Hap were localized to the N-lobe of the bilobed lactoferrin molecule and were inhibited by serine protease inhibitors, suggesting that the lactoferrin N-lobe may contain serine protease activity. Additional experiments revealed no effect of lactoferrin on the H. influenzae P2, P5, and P6 outer-membrane proteins, which are distinguished from IgA1 protease and Hap by the lack of an N-terminal passenger domain or an extracellular linker region. These results suggest that human milk lactoferrin may attenuate the pathogenic potential of H. influenzae by selectively inactivating IgA1 protease and Hap, thereby interfering with colonization. Future studies should examine the therapeutic potential of lactoferrin, perhaps as a supplement in infant formulas.

  13. Haemophilus ducreyi Outer Membrane Determinants, Including DsrA, Define Two Clonal Populations

    PubMed Central

    White, Catherine Dinitra; Leduc, Isabelle; Olsen, Bonnie; Jeter, Chrystina; Harris, Chavala; Elkins, Christopher

    2005-01-01

    The Haemophilus ducreyi outer membrane component DsrA (for ducreyi serum resistance A) is necessary for complete resistance to normal human serum (NHS). When DsrA expression in 19 temporally and geographically diverse clinical isolates of H. ducreyi was examined by Western blotting, 5 of the strains expressed a different immunotype of the DsrA protein (DsrAII) than the well-characterized prototypical strain 35000HP (DsrAI). The predicted DsrA proteins expressed by the DsrAII strains were 100% identical to each other but only 48% identical to that of strain 35000HP. In addition to the DsrAII protein, class II strains also expressed variant forms of other outer membrane proteins (OMPs) including NcaA (necessary for collagen adhesion A), DltA (ducreyi lectin A), Hlp (H. ducreyi lipoprotein), major OMP, and/or OmpA2 (for OMP A2) and synthesized a distinct, faster-migrating lipooligosaccharide. Based on these data, strains expressing DsrAI were termed class I, and those expressing DsrAII were termed class II. Expression of dsrAII from strain CIP 542 ATCC in the class I dsrAI mutant FX517 (35000HP background), which does not express a DsrA protein, rendered this strain resistant to 50% NHS. This demonstrates that DsrAII protein is also critical to serum resistance. Taken together, these results indicate that there are two clonal populations of H. ducreyi. The implications of two classes of H. ducreyi strains differing in important antigenic outer membrane components are discussed. PMID:15784585

  14. Defining Potential Vaccine Targets of Haemophilus ducreyi Trimeric Autotransporter Adhesin DsrA

    PubMed Central

    Fusco, William G.; Choudhary, Neelima R.; Stewart, Shelley M.; Alam, S. Munir; Sempowski, Gregory D.; Elkins, Christopher

    2015-01-01

    Haemophilus ducreyi is the causative agent of the sexually transmitted genital ulcer disease chancroid. Strains of H. ducreyi are grouped in two classes (I and II) based on genotypic and phenotypic differences, including those found in DsrA, an outer membrane protein belonging to the family of multifunctional trimeric autotransporter adhesins. DsrA is a key serum resistance factor of H. ducreyi that prevents binding of natural IgM at the bacterial surface and functions as an adhesin to fibronectin, fibrinogen, vitronectin, and human keratinocytes. Monoclonal antibodies (MAbs) were developed to recombinant DsrA (DsrAI) from prototypical class I strain 35000HP to define targets for vaccine and/or therapeutics. Two anti-DsrAI MAbs bound monomers and multimers of DsrA from genital and non-genital/cutaneous H. ducreyi strains in a Western blot and reacted to the surface of the genital strains; however, these MAbs did not recognize denatured or native DsrA from class II strains. In a modified extracellular matrix protein binding assay using viable H. ducreyi, one of the MAbs partially inhibited binding of fibronectin, fibrinogen, and vitronectin to class I H. ducreyi strain 35000HP, suggesting a role for anti-DsrA antibodies in preventing binding of H. ducreyi to extracellular matrix proteins. Standard ELISA and surface plasmon resonance using a peptide library representing full-length, mature DsrAI revealed the smallest nominal epitope bound by one of the MAbs to be MEQNTHNINKLS. Taken together, our findings suggest that this epitope is a potential target for an H. ducreyi vaccine. PMID:25897604

  15. Defining Potential Vaccine Targets of Haemophilus ducreyi Trimeric Autotransporter Adhesin DsrA.

    PubMed

    Fusco, William G; Choudhary, Neelima R; Stewart, Shelley M; Alam, S Munir; Sempowski, Gregory D; Elkins, Christopher; Leduc, Isabelle

    2015-04-01

    Haemophilus ducreyi is the causative agent of the sexually transmitted genital ulcer disease chancroid. Strains of H. ducreyi are grouped in two classes (I and II) based on genotypic and phenotypic differences, including those found in DsrA, an outer membrane protein belonging to the family of multifunctional trimeric autotransporter adhesins. DsrA is a key serum resistance factor of H. ducreyi that prevents binding of natural IgM at the bacterial surface and functions as an adhesin to fibronectin, fibrinogen, vitronectin, and human keratinocytes. Monoclonal antibodies (MAbs) were developed to recombinant DsrA (DsrA(I)) from prototypical class I strain 35000HP to define targets for vaccine and/or therapeutics. Two anti-DsrAI MAbs bound monomers and multimers of DsrA from genital and non-genital/cutaneous H. ducreyi strains in a Western blot and reacted to the surface of the genital strains; however, these MAbs did not recognize denatured or native DsrA from class II strains. In a modified extracellular matrix protein binding assay using viable H. ducreyi, one of the MAbs partially inhibited binding of fibronectin, fibrinogen, and vitronectin to class I H. ducreyi strain 35000HP, suggesting a role for anti-DsrA antibodies in preventing binding of H. ducreyi to extracellular matrix proteins. Standard ELISA and surface plasmon resonance using a peptide library representing full-length, mature DsrAI revealed the smallest nominal epitope bound by one of the MAbs to be MEQNTHNINKLS. Taken together, our findings suggest that this epitope is a potential target for an H. ducreyi vaccine.

  16. Crystal structure of the Haemophilus influenzae Hap adhesin reveals an intercellular oligomerization mechanism for bacterial aggregation

    PubMed Central

    Meng, Guoyu; Spahich, Nicole; Kenjale, Roma; Waksman, Gabriel; St Geme, Joseph W

    2011-01-01

    Bacterial biofilms are complex microbial communities that are common in nature and are being recognized increasingly as an important determinant of bacterial virulence. However, the structural determinants of bacterial aggregation and eventual biofilm formation have been poorly defined. In Gram-negative bacteria, a major subgroup of extracellular proteins called self-associating autotransporters (SAATs) can mediate cell–cell adhesion and facilitate biofilm formation. In this study, we used the Haemophilus influenzae Hap autotransporter as a prototype SAAT to understand how bacteria associate with each other. The crystal structure of the H. influenzae HapS passenger domain (harbouring the SAAT domain) was determined to 2.2 Å by X-ray crystallography, revealing an unprecedented intercellular oligomerization mechanism for cell–cell interaction. The C-terminal SAAT domain folds into a triangular-prism-like structure that can mediate Hap–Hap dimerization and higher degrees of multimerization through its F1–F2 edge and F2 face. The intercellular multimerization can give rise to massive buried surfaces that are required for overcoming the repulsive force between cells, leading to bacterial cell–cell interaction and formation of complex microcolonies. PMID:21841773

  17. Multilocus sequence typing and virulence analysis of Haemophilus parasuis strains isolated in five provinces of China.

    PubMed

    Wang, Liyan; Ma, Lina; Liu, Yongan; Gao, Pengcheng; Li, Youquan; Li, Xuerui; Liu, Yongsheng

    2016-10-01

    Haemophilus parasuis is the etiological agent of Glässers disease, which causes high morbidity and mortality in swine herds. Although H. parasuis strains can be classified into 15 serovars with the Kielstein-Rapp-Gabrielson serotyping scheme, a large number of isolates cannot be classified and have been designated 'nontypeable' strains. In this study, multilocus sequence typing (MLST) of H. parasuis was used to analyze 48 H. parasuis field strains isolated in China and two strains from Australia. Twenty-six new alleles and 29 new sequence types (STs) were detected, enriching the H. parasuis MLST databases. A BURST analysis indicated that H. parasuis lacks stable population structure and is highly heterogeneous, and that there is no association between STs and geographic area. When an UPGMA dendrogram was constructed, two major clades, clade A and clade B, were defined. Animal experiments, in which guinea pigs were challenged intraperitoneally with the bacterial isolates, supported the hypothesis that the H. parasuis STs in clade A are generally avirulent or weakly virulent, whereas the STs in clade B tend to be virulent. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Action for child survival: elimination of Haemophilus influenzae type b meningitis in Uganda.

    PubMed

    Lewis, Rosamund F; Kisakye, Annet; Gessner, Bradford D; Duku, Chaplain; Odipio, John Bosco; Iriso, Robert; Nansera, Denis; Braka, Fiona; Makumbi, Issa; Kekitiinwa, Addy

    2008-04-01

    To guide immunization policy, we determined the public health benefit of introducing Haemophilus influenzae type b (Hib) vaccine in Uganda and estimated the vaccine effectiveness. Surveillance data for acute bacterial meningitis among children aged 0-59 months were reviewed from three hospital sentinel sites, for July 2001 to June 2007, to determine the incidence of Hib meningitis, the effectiveness of Hib vaccine with a case-control design, and the number of vaccine-preventable cases and deaths of Hib disease in Uganda. Of the 13 978 children from 17 districts with suspected bacterial meningitis, 269 had confirmed Hib meningitis, declining from 69 patients in the prevaccine year (2001-2002) to three in 2006-2007. Hib meningitis incidence dropped from 88 cases per 100,000 children aged < 5 years in the year before vaccine introduction to 13 within 4 years, and to near zero in the fifth year. Vaccine effectiveness for 2 or more doses was 93% (95% confidence interval, CI: 69-99) against confirmed Hib meningitis and 53% (95% CI: 11-68) against purulent meningitis of unknown cause. In Uganda, Hib vaccine prevents an estimated 28 000 cases of pneumonia and meningitis, 5000 deaths and 1000 severe meningitis sequelae each year. Infant immunization with Hib vaccine has virtually eliminated Hib meningitis in Uganda within 5 years. Ensuring long-term benefits of Hib vaccine urgently requires sustainable vaccine financing, high-quality ongoing surveillance, and a health sector able to deliver a robust immunization programme.

  19. Biofilm Growth Increases Phosphorylcholine Content and Decreases Potency of Nontypeable Haemophilus influenzae Endotoxins

    PubMed Central

    West-Barnette, Shayla; Rockel, Andrea; Swords, W. Edward

    2006-01-01

    Nontypeable Haemophilus influenzae (NTHI) is a common respiratory commensal and opportunistic pathogen. NTHI is normally contained within the airways by host innate defenses that include recognition of bacterial endotoxins by Toll-like receptor 4 (TLR4). NTHI produces lipooligosaccharide (LOS) endotoxins which lack polymeric O side chains and which may contain host glycolipids. We recently showed that NTHI biofilms contain variants with sialylated LOS glycoforms that are essential to biofilm formation. In this study, we show that NTHI forms biofilms on epithelial cell layers. Confocal analysis revealed that sialylated variants were distributed throughout the biofilm, while variants expressing phosphorylcholine (PCho) were found within the biofilm. Consistent with this observation, PCho content of LOS purified from NTHI biofilms was increased compared to LOS from planktonic cultures. Hypothesizing that the observed changes in endotoxin composition could affect bioactivity, we compared inflammatory responses to NTHI LOS purified from biofilm and planktonic cultures. Our results show that endotoxins from biofilms induced weaker host innate responses. While we observed a minimal effect of sialylation on LOS bioactivity, there was a significant decrease in bioactivity associated with PCho substitutions. We thus conclude that biofilm growth increases the proportion of PCho+ variants in an NTHI population, resulting in a net decrease in LOS bioactivity. Thus, in addition to their well-documented resistance phenotypes, our data show that biofilm communities of NTHI bacteria contain variants that evoke less potent host responses. PMID:16495557

  20. Impact and cost-effectiveness of Haemophilus influenzae type b conjugate vaccination in India.

    PubMed

    Clark, Andrew D; Griffiths, Ulla K; Abbas, Syed Shahid; Rao, Krishna D; Privor-Dumm, Lois; Hajjeh, Rana; Johnson, Hope; Sanderson, Colin; Santosham, Mathuram

    2013-07-01

    To estimate the potential health impact and cost-effectiveness of nationwide Haemophilus influenzae type b (Hib) vaccination in India. A decision support model was used, bringing together estimates of demography, epidemiology, Hib vaccine effectiveness, Hib vaccine costs, and health care costs. Scenarios favorable and unfavorable to the vaccine were evaluated. State-level analyses indicate where the vaccine might have the greatest impact and value. Between 2012 and 2031, Hib conjugate vaccination is estimated to prevent over 200 000 child deaths (∼1% of deaths in children <5 years of age) in India at an incremental cost of US$127 million per year. From a government perspective, state-level cost-effectiveness ranged from US$192 to US$1033 per discounted disability adjusted life years averted. With the inclusion of household health care costs, cost-effectiveness ranged from US$155-US$939 per discounted disability adjusted life year averted. These values are below the World Health Organization thresholds for cost effectiveness of public health interventions. Hib conjugate vaccination is a cost-effective intervention in all States of India. This conclusion does not alter with plausible changes in key parameters. Although investment in Hib conjugate vaccination would significantly increase the cost of the Universal Immunization Program, about 15% of the incremental cost would be offset by health care cost savings. Efforts should be made to expedite the nationwide introduction of Hib conjugate vaccination in India. Copyright © 2013. Published by Mosby, Inc.

  1. Impact and Cost-Effectiveness of Haemophilus influenzae Type b Conjugate Vaccination in India

    PubMed Central

    Clark, Andrew D.; Griffiths, Ulla K.; Abbas, Syed Shahid; Rao, Krishna D.; Privor-Dumm, Lois; Hajjeh, Rana; Johnson, Hope; Sanderson, Colin; Santosham, Mathuram

    2017-01-01

    Objective To estimate the potential health impact and cost-effectiveness of nationwide Haemophilus influenzae type b (Hib) vaccination in India. Study design A decision support model was used, bringing together estimates of demography, epidemiology, Hib vaccine effectiveness, Hib vaccine costs, and health care costs. Scenarios favorable and unfavorable to the vaccine were evaluated. State-level analyses indicate where the vaccine might have the greatest impact and value. Results Between 2012 and 2031, Hib conjugate vaccination is estimated to prevent over 200 000 child deaths (~1% of deaths in children <5 years of age) in India at an incremental cost of US$127 million per year. From a government perspective, state-level cost-effectiveness ranged from US$192 to US$1033 per discounted disability adjusted life years averted. With the inclusion of household health care costs, cost-effectiveness ranged from US$155-US$939 per discounted disability adjusted life year averted. These values are below the World Health Organization thresholds for cost effectiveness of public health interventions. Conclusions Hib conjugate vaccination is a cost-effective intervention in all States of India. This conclusion does not alter with plausible changes in key parameters. Although investment in Hib conjugate vaccination would significantly increase the cost of the Universal Immunization Program, about 15% of the incremental cost would be offset by health care cost savings. Efforts should be made to expedite the nationwide introduction of Hib conjugate vaccination in India. PMID:23773596

  2. Tracing phylogenomic events leading to diversity of Haemophilus influenzae and the emergence of Brazilian Purpuric Fever (BPF)-associated clones.

    PubMed

    Papazisi, Leka; Ratnayake, Shashikala; Remortel, Brian G; Bock, Geoffrey R; Liang, Wei; Saeed, Alexander I; Liu, Jia; Fleischmann, Robert D; Kilian, Mogens; Peterson, Scott N

    2010-11-01

    Here we report the use of a multi-genome DNA microarray to elucidate the genomic events associated with the emergence of the clonal variants of Haemophilus influenzae biogroup aegyptius causing Brazilian Purpuric Fever (BPF), an important pediatric disease with a high mortality rate. We performed directed genome sequencing of strain HK1212 unique loci to construct a species DNA microarray. Comparative genome hybridization using this microarray enabled us to determine and compare gene complements, and infer reliable phylogenomic relationships among members of the species. The higher genomic variability observed in the genomes of BPF-related strains (clones) and their close relatives may be characterized by significant gene flux related to a subset of functional role categories. We found that the acquisition of a large number of virulence determinants featuring numerous cell membrane proteins coupled to the loss of genes involved in transport, central biosynthetic pathways and in particular, energy production pathways to be characteristics of the BPF genomic variants. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Comparison of enzyme immunoassays for antibodies to Haemophilus ducreyi in a community outbreak of chancroid in the United States.

    PubMed

    Chen, C Y; Mertz, K J; Spinola, S M; Morse, S A

    1997-06-01

    The performance of two EIAs (adsorption EIA and lipooligosaccharide [LOS] EIA) that detect antibodies to Haemophilus ducreyi was evaluated with serum specimens obtained from 163 patients (96 with genital ulcer disease [GUD]). Paired serum specimens (initial and follow-up) were obtained from 52 of the GUD patients. By use of initial serum specimens from 82 GUD patients whose etiologic agents for their ulcers had been identified, the adsorption EIA had a sensitivity and specificity for chancroid of 53% and 71%, while the LOS EIA had a sensitivity and specificity of 48% and 89%, respectively. Sensitivity and specificity of the adsorption EIA increased to 78% and 84%, respectively, when the results of follow-up serum specimens were used to calculate optimal performance. The proportion of patients testing positive for H. ducreyi who had anti-H. ducreyi IgG antibodies, as determined by adsorption EIA, increased with the duration of infection, thus limiting the role of EIAs in the diagnosis of chancroid.

  4. In vitro stimulation of peripheral blood mononuclear cells (PBMC) from HIV- and HIV+ chancroid patients by Haemophilus ducreyi antigens.

    PubMed Central

    Van Laer, L; Vingerhoets, J; Vanham, G; Kestens, L; Bwayo, J; Otido, J; Piot, P; Roggen, E

    1995-01-01

    The cellular immune responses to fractionated Haemophilus ducreyi antigens, coated on latex beads, were assessed in patients with chancroid and in controls, using an in vitro lymphocyte proliferation assay. Several fractions of H. ducreyi antigen revealed stimulating activity. However, only the molecular size ranges 91-78 kD, 59-29 kD, and 25-21 kD induced proliferation that may be specifically related to H. ducreyi infection. Lymphocytes from four HIV- patients, successfully treated for chancroid, were not stimulated by H. ducreyi antigen. In general, lymphocytes from HIV+ chancroid patients were less responsive to H. ducreyi antigen compared with those from HIV- chancroid patients. However, two HIV-infected patients showed exceptionally strong responses to high molecular weight fractions. To our knowledge this is the first report demonstrating that H. ducreyi contains specific T cell-stimulating antigens. Based on this work, further identification and purification of the T cell antigens is feasible. PMID:7586673

  5. In vitro stimulation of peripheral blood mononuclear cells (PBMC) from HIV- and HIV+ chancroid patients by Haemophilus ducreyi antigens.

    PubMed

    Van Laer, L; Vingerhoets, J; Vanham, G; Kestens, L; Bwayo, J; Otido, J; Piot, P; Roggen, E

    1995-11-01

    The cellular immune responses to fractionated Haemophilus ducreyi antigens, coated on latex beads, were assessed in patients with chancroid and in controls, using an in vitro lymphocyte proliferation assay. Several fractions of H. ducreyi antigen revealed stimulating activity. However, only the molecular size ranges 91-78 kD, 59-29 kD, and 25-21 kD induced proliferation that may be specifically related to H. ducreyi infection. Lymphocytes from four HIV- patients, successfully treated for chancroid, were not stimulated by H. ducreyi antigen. In general, lymphocytes from HIV+ chancroid patients were less responsive to H. ducreyi antigen compared with those from HIV- chancroid patients. However, two HIV-infected patients showed exceptionally strong responses to high molecular weight fractions. To our knowledge this is the first report demonstrating that H. ducreyi contains specific T cell-stimulating antigens. Based on this work, further identification and purification of the T cell antigens is feasible.

  6. Haemophilus influenzae pneumonia in human immunodeficiency virus-infected patients. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

    PubMed

    Cordero, E; Pachón, J; Rivero, A; Girón, J A; Gómez-Mateos, J; Merino, M D; Torres-Tortosa, M; González-Serrano, M; Aliaga, L; Collado, A; Hernández-Quero, J; Barrera, A; Nuño, E

    2000-03-01

    Although Haemophilus influenzae is a common etiologic agent of pneumonia in patients infected with human immunodeficiency virus (HIV), the characteristics of this pneumonia have not been adequately assessed. We have prospectively studied features of H. influenzae pneumonia in 26 consecutive HIV-infected inpatients. Most of these patients were severely immunosuppressed; 73.1% had a CD4+ cell count <100/microL. A subacute clinical presentation was observed in 27% of the patients and was associated with a higher degree of immunosuppression (P=.04). Bilateral lung infiltrates were noted radiographically in 57.7% of the cases. The mortality attributable to H. influenzae pneumonia was 11.5%. Thus, pneumonia caused by H. influenzae affects mainly patients with advanced HIV disease, and since its clinical and radiological features may be diverse, this etiology should be considered when pneumonia occurs in patients with advanced HIV infection. The mortality rate associated with H. influenzae pneumonia is not higher than that occurring in the general population.

  7. Quantitation of antibodies to Haemophilus influenzae type b in humans by enzyme-linked immunosorbent assay.

    PubMed Central

    Dahlberg, T

    1981-01-01

    The enzyme-linked immunosorbent assay was adapted to detect serum immunoglobulin G, immunoglobulin M, immunoglobulin A, and secretory immunoglobulin A antibodies to Haemophilus influenzae type b capsular polysaccharide in humans. I studied serum samples from 92 healthy children of various ages, 50 healthy adults, 24 patients with various H. influenzae type b infections, and 16 patients with clinical signs of epiglottis and cellulitis suspected to be caused by H. influenzae type b. The mean antibody titers of the sera from healthy children increased with age and reached adult levels in children more than 6 years old. A significant antibody response to capsular polysaccharide was observed in serum samples from the majority of patients with infections due to H. influenzae type b and in 4 of 16 patients with clinical signs of epiglottis and cellulitis. In addition to the enzyme-linked immunosorbent assay, the antibody responses of patients were tested by a bactericidal assay. When the two methods were compared, there was no evident correlation (r, about 0.22). The enzyme-linked immunosorbent assay was further adapted to test secretory immunoglobulin A antibodies specific to capsular polysaccharide in nasopharynx secretions and in milk samples from lactating women. Antibodies were detected in 12 of 24 secretions and 9 of 11 milk samples. PMID:7019237

  8. Haemophilus influenzae activity in a single medical center in Israel in the post-vaccine era.

    PubMed

    Megged, Orli; Bar-Meir, Maskit; Schlesinger, Yechiel

    2012-07-01

    The incidence of invasive disease due to Haemophilus influenzae has decreased since the implementation of vaccination against serotype B. To describe the epidemiological, clinical and microbiological characteristics of patients with H. influenzae meningitis or bacteremia in the vaccine era in Israel. We reviewed the medical records of all patients admitted to Shaare Zedek Medical Center between 1997 and 2010 who had blood or cerebrospinal fluid culture positive for H. influenzae. The study group comprised 104 patients - 57 children and 47 adults. Overall, 21 (20%) of the infections were due to serotype b. The children had shorter hospitalizations (6vs. 12 days, P = 0.005) and lower mortality rate (5% vs. 28%, P = 0.003) as compared to the adults. Bacteremic pneumonia was the most common diagnosis in adults (45% vs. 28% in children, P = 0.08) while meningitis was more common in children (17% vs. 3.5%, P = 0.09). There was a seasonal pattern, with infections being more common during the winter and spring. Invasive H. influenzae disease is uncommon but still exists in both children and adults. The disease course tends to be more severe in adults. Even in the global vaccination era, serotype b constitutes a significant portion of invasive disease.

  9. Methodology optimization and diversification for the investigation of virulence potential in Haemophilus influenzae clinical strains.

    PubMed

    Giucă, Mihaela Cristina; Străuţ, Monica; Surdeanu, Maria; Nica, Maria; Ungureanu, Vasilica; Mihăescu, Grigore

    2011-01-01

    Ten Haemophilus influenzae strains were isolated from patients aged between 1.6 - 24 years, with various diagnoses (acute meningitis, acute upper respiratory infection, otitis media and acute sinusitis). Identification was based on phenotypic and molecular characteristics; antibiotic susceptibility testing was performed by diffusion method according to CLSI standards 2011 for seven antibiotics. The results of molecular testing showed that all the studied strains produced an amplicon of 1000 bp with ompP2 primers indicating that all strains were H. influenzae. For six strains, the PCR amplicon obtained with bexA specific primers, proving that the strains were capsulated. The results of phenotypic testing showed that four strains were ampicillin nonsusceptible and (beta-lactamase-positive. The virulence potential of H. influenzae clinical strains was investigated by phenotypic methods, including the assessment of the soluble virulence factors on specific media containing the biochemical substratum for the investigated enzymatic factor, as well as the adherence and invasion capacity to HeLa cells monolayer using Cravioto modified method. The studied strains exhibited mainly a diffuse adherence pattern and different adherence indexes. Interestingly, two strains isolated from the same pacient (blood and CSF) showed a different degree of invasiveness, the strain isolated from blood being 20 times more invasive than the one isolated from CSF.

  10. Loop-mediated isothermal amplification assay for detection of Haemophilus influenzae type b in cerebrospinal fluid.

    PubMed

    Kim, Dong Wook; Kilgore, Paul Evan; Kim, Eun Jin; Kim, Soon Ae; Anh, Dang Duc; Seki, Mitsuko

    2011-10-01

    Haemophilus influenzae type b (Hib) is one of the leading causes of meningitis in developing countries. To establish and evaluate a novel loop-mediated isothermal amplification (LAMP) assay for Hib, we designed a LAMP primer set targeting the Hib-specific capsulation locus. LAMP detected 10 copies of purified DNA in a 60-min reaction. This indicated that the detection limit of LAMP was >100-fold lower than the detection limits of both a PCR for the detection of bexA and a nested PCR for Hib (Hib PCR). No H. influenzae, other than Hib or control bacteria, was detected. Linear determination ranged from 10 to 1,000,000 microorganisms per reaction mixture using real-time turbidimetry. We evaluated the Hib LAMP assay using a set of 52 randomly selected cerebrospinal fluid (CSF) specimens obtained from children with suspected meningitis. For comparison, the CSF specimens were tested using a conventional Hib PCR assay. Hib was detected in 30 samples using LAMP and in 22 samples using the Hib PCR assay. The Hib PCR showed a clinical sensitivity of 73.3% and a clinical specificity of 100% relative to the Hib LAMP assay. These results suggest that further development and evaluation of the Hib LAMP will enhance the global diagnostic capability for Hib detection.

  11. Structural Analysis of Substrate, Reaction Intermediate, and Product Binding in Haemophilus influenzae Biotin Carboxylase

    PubMed Central

    Broussard, Tyler C.; Pakhomova, Svetlana; Neau, David B.; Bonnot, Ross; Waldrop, Grover L.

    2015-01-01

    Acetyl-CoA carboxylase catalyzes the first and regulated step in fatty acid synthesis. In most Gram-negative and Gram-positive bacteria, the enzyme is composed of three proteins: biotin carboxylase, a biotin carboxyl carrier protein (BCCP), and carboxyltransferase. The reaction mechanism involves two half-reactions with biotin carboxylase catalyzing the ATP-dependent carboxylation of biotin-BCCP in the first reaction. In the second reaction, carboxyltransferase catalyzes the transfer of the carboxyl group from biotin-BCCP to acetyl-CoA to form malonyl-CoA. In this report, high-resolution crystal structures of biotin carboxylase from Haemophilus influenzae were determined with bicarbonate, the ATP analogue AMPPCP; the carboxyphosphate intermediate analogues, phosphonoacetamide and phosphonoformate; the products ADP and phosphate; and the carboxybiotin analogue N1′-methoxycarbonyl biotin methyl ester. The structures have a common theme in that bicarbonate, phosphate, and the methyl ester of the carboxyl group of N1′-methoxycarbonyl biotin methyl ester all bound in the same pocket in the active site of biotin carboxylase and as such utilize the same set of amino acids for binding. This finding suggests a catalytic mechanism for biotin carboxylase in which the binding pocket that binds tetrahedral phosphate also accommodates and stabilizes a tetrahedral dianionic transition state resulting from direct transfer of CO2 from the carboxyphosphate intermediate to biotin. PMID:26020841

  12. “Pathotyping” Multiplex PCR Assay for Haemophilus parasuis: a Tool for Prediction of Virulence

    PubMed Central

    Weinert, Lucy A.; Peters, Sarah E.; Wang, Jinhong; Hernandez-Garcia, Juan; Chaudhuri, Roy R.; Luan, Shi-Lu; Angen, Øystein; Aragon, Virginia; Williamson, Susanna M.; Rycroft, Andrew N.; Wren, Brendan W.; Maskell, Duncan J.; Tucker, Alexander W.

    2017-01-01

    ABSTRACT Haemophilus parasuis is a diverse bacterial species that is found in the upper respiratory tracts of pigs and can also cause Glässer's disease and pneumonia. A previous pangenome study of H. parasuis identified 48 genes that were associated with clinical disease. Here, we describe the development of a generalized linear model (termed a pathotyping model) to predict the potential virulence of isolates of H. parasuis based on a subset of 10 genes from the pangenome. A multiplex PCR (mPCR) was constructed based on these genes, the results of which were entered into the pathotyping model to yield a prediction of virulence. This new diagnostic mPCR was tested on 143 field isolates of H. parasuis that had previously been whole-genome sequenced and a further 84 isolates from the United Kingdom from cases of H. parasuis-related disease in pigs collected between 2013 and 2014. The combination of the mPCR and the pathotyping model predicted the virulence of an isolate with 78% accuracy for the original isolate collection and 90% for the additional isolate collection, providing an overall accuracy of 83% (81% sensitivity and 93% specificity) compared with that of the “current standard” of detailed clinical metadata. This new pathotyping assay has the potential to aid surveillance and disease control in addition to serotyping data. PMID:28615466

  13. Pharmacokinetics of tilmicosin in healthy pigs and in pigs experimentally infected with Haemophilus parasuis

    PubMed Central

    Zhang, Ling; Zhao, Li; Liu, Yonghong; Liu, Junfeng

    2017-01-01

    A comparative in vivo pharmacokinetic (PK) study of tilmicosin (TIL) was conducted in 6 crossbred healthy pigs and 6 crossbred pigs infected with Haemophilus (H.) parasuis following oral administration of a single 40 mg/kg dose. The infected model was established by intranasal inoculation and confirmed by clinical signs, blood biochemistry, and microscopic examinations. Plasma TIL concentrations were determined by a validated high-performance liquid chromatography method with ultraviolet detection at 285 nm. PK parameters were calculated by using WinNonlin software. After TIL administration, the main PK parameters of TIL in healthy and H. parasuis-infected pigs were as follows: Area under the concentration-time curve, maximal drug concentration, half-life of the absorption phase, half-life of the distribution phase, and half-life of the elimination phase were 34.86 ± 9.69 vs. 28.73 ± 6.18 µg · h/mL, 1.77 ± 0.33 vs. 1.67 ± 0.28 µg/mL, 2.27 ± 0.45 vs. 2.24 ± 0.44 h, 5.35 ± 1.40 vs. 4.61 ± 0.35 h, and 43.53 ± 8.17 vs. 42.05 ± 9.36 h, respectively. These results of this exploratory study suggest that there were no significant differences between the PK profiles of TIL in the healthy and H. parasuis-infected pigs. PMID:28385011

  14. Pharmacokinetics of tilmicosin in healthy pigs and in pigs experimentally infected with Haemophilus parasuis.

    PubMed

    Zhang, Ling; Zhao, Li; Liu, Yonghong; Liu, Junfeng; Li, Xianqiang

    2017-12-31

    A comparative in vivo pharmacokinetic (PK) study of tilmicosin (TIL) was conducted in 6 crossbred healthy pigs and 6 crossbred pigs infected with Haemophilus ( H .) parasuis following oral administration of a single 40 mg/kg dose. The infected model was established by intranasal inoculation and confirmed by clinical signs, blood biochemistry, and microscopic examinations. Plasma TIL concentrations were determined by a validated high-performance liquid chromatography method with ultraviolet detection at 285 nm. PK parameters were calculated by using WinNonlin software. After TIL administration, the main PK parameters of TIL in healthy and H. parasuis -infected pigs were as follows: Area under the concentration-time curve, maximal drug concentration, half-life of the absorption phase, half-life of the distribution phase, and half-life of the elimination phase were 34.86 ± 9.69 vs. 28.73 ± 6.18 μgㆍh/mL, 1.77 ± 0.33 vs. 1.67 ± 0.28 μg/mL, 2.27 ± 0.45 vs. 2.24 ± 0.44 h, 5.35 ± 1.40 vs. 4.61 ± 0.35 h, and 43.53 ± 8.17 vs. 42.05 ± 9.36 h, respectively. These results of this exploratory study suggest that there were no significant differences between the PK profiles of TIL in the healthy and H. parasuis -infected pigs.

  15. Characterization of nasopharyngeal isolates of type b Haemophilus influenzae from Delhi

    PubMed Central

    Saikia, Kandarpa K.; Das, Bimal K.; Bewal, Ramesh K.; Kapil, Arti; Arora, N.K.; Sood, Seema

    2012-01-01

    Background & objectives: Haemophilus influenzae is an important cause of mortality and morbidity among young children in developing countries. Increasing incidence of antibiotic resistance especially production of extended spectrum beta lactamase (ESBL) has made treatment and management of H. influenzae infection more difficult. Nasopharyngeal H. influenzae isolates are excellent surrogate for determination of antibiotic resistance prevalent among invasive H. influenzae isolates. In this study, we characterized nasopharyngeal H. influenzae isolates obtained from healthy school going children in Delhi. Methods: Nasopharyngeal H. influenzae isolates were collected from healthy school going children and subjected to serotyping, fimbrial typing and antibiogram profiling. ESBL production was recorded using phenotypic as well as molecular methods. Multi locus sequence typing (MLST) of 13 representative nasopharyngeal H. influenzae isolates was performed as per guidelines. Results: A significant proportion (26 of 80, 32.5%) of nasopharyngeal isolates of H. influenzae were identified as serotype b. Fimbrial gene (hifA) was detected in 23 (28.75%) isolates. Resistance against commonly prescribed antibiotics (Amp, Tet, Chloro, Septran, Cephalexin) were observed to be high among the nasopharyngeal commensal H. influenzae. Extended spectrum beta lactamase (ESBL) production was observed in a five (6.25%) isolates by both double disk diffusion and molecular typing. MLST identified several novel alleles as well as novel sequence types. Interpretation & conclusions: Our findings showed high resistance against common antibiotics and detection of ESBL in nasopharyngeal H. influenzae isolates collected from normal healthy school going children in Delhi. Detection of H. influenzae type b capsular gene and the presence of fimbrial gene (hif A) suggest virulence potential of these isolates. Discovery of novel alleles and presence of new sequence types (STs) among nasopharyngeal H

  16. Cost-effectiveness of Haemophilus influenzae type b vaccine in Vietnam

    PubMed Central

    Le, Phuc; Griffiths, Ulla K.; Anh, Dang Duc; Franzini, Luisa; Chan, Wenyaw; Swint, J. Michael

    2015-01-01

    Background With GAVI support, Vietnam introduced Haemophilus influenzae type b (Hib) vaccine in 2010 without evidence on cost-effectiveness. We aimed to analyze the cost-effectiveness of Hib vaccine from societal and governmental perspectives. Method We constructed a decision-tree cohort model to estimate the costs and effectiveness of Hib vaccine versus no Hib vaccine for the 2011 birth cohort. The disease burden was estimated from local epidemiologic data and literature. Vaccine delivery costs were calculated from governmental reports and 2013 vaccine prices. A prospective cost-of-illness study was conducted to estimate treatment costs. The human capital approach was employed to estimate productivity loss. The incremental costs of Hib vaccine were divided by cases, deaths, and disability-adjusted life years (DALY) averted. We used the WHO recommended cost-effectiveness thresholds of an intervention being highly cost-effective if incremental costs per DALY were below GDP per capita. Result From the societal perspective, incremental costs per discounted case, death and DALY averted were US$ 6,252, US$ 26,476 and US$ 1,231, respectively; the break-even vaccine price was US$ 0.69/dose. From the governmental perspective, the results were US$ 6,954, US$ 29,449, and US$ 1,373, respectively; the break-even vaccine price was US$ 0.48/dose. Vietnam's GDP per capita was US$ 1,911 in 2013. In deterministic sensitivity analysis, morbidity and mortality parameters were among the most influential factors. In probabilistic sensitivity analysis, Hib vaccine had an 84% and 78% probability to be highly cost-effective from the societal and governmental perspectives, respectively. Conclusion Hib vaccine was highly cost-effective from both societal and governmental perspectives. However, with GAVI support ending in 2016, the government will face a six-fold increase in its vaccine budget at the 2013 vaccine price. The variability of vaccine market prices adds an element of uncertainty

  17. Haemophilus influenzae type b-Neisseria meningitidis serogroups C and Y tetanus toxoid conjugate vaccine for infants and toddlers.

    PubMed

    Bryant, Kristina A; Marshall, Gary S

    2011-07-01

    The highest rates of invasive meningococcal disease occur in children under 2 years of age, yet as of early 2011 no vaccine was licensed for the youngest infants. However, a novel vaccine consisting of capsular polysaccharides from Haemophilus influenzae type b (Hib) and Neisseria meningitidis serogroups C and Y conjugated to tetanus toxoid (HibMenCY-TT; MenHibrix, GlaxoSmithKline) is in the late stages of development. In clinical trials involving more than 7800 children, HibMenCY-TT was shown to be safe and immunogenic when administered at 2, 4, 6 and 12-15 months of age. Anti-polyribosylribitol phosphate antibody responses were noninferior to those elicited by licensed monovalent Hib vaccines, and most vaccinees developed bactericidal antibodies against N. meningitidis serogroups C and Y. The majority of subjects retained antibody responses as far as 3 years after vaccination. If licensed, HibMenCY-TT not only represents an incremental option for protection against invasive Hib, but also has the potential to prevent invasive meningococcal disease without increasing the number of injections.

  18. Coupling of NAD+ biosynthesis and nicotinamide ribosyl transport: characterization of NadR ribonucleotide kinase mutants of Haemophilus influenzae.

    PubMed

    Merdanovic, Melisa; Sauer, Elizabeta; Reidl, Joachim

    2005-07-01

    Previously, we characterized a pathway necessary for the processing of NAD+ and for uptake of nicotinamide riboside (NR) in Haemophilus influenzae. Here we report on the role of NadR, which is essential for NAD+ utilization in this organism. Different NadR variants with a deleted ribonucleotide kinase domain or with a single amino acid change were characterized in vitro and in vivo with respect to cell viability, ribonucleotide kinase activity, and NR transport. The ribonucleotide kinase mutants were viable only in a nadV+ (nicotinamide phosphoribosyltransferase) background, indicating that the ribonucleotide kinase domain is essential for cell viability in H. influenzae. Mutations located in the Walker A and B motifs and the LID region resulted in deficiencies in both NR phosphorylation and NR uptake. The ribonucleotide kinase function of NadR was found to be feedback controlled by NAD+ under in vitro conditions and by NAD+ utilization in vivo. Taken together, our data demonstrate that the NR phosphorylation step is essential for both NR uptake across the inner membrane and NAD+ synthesis and is also involved in controlling the NAD+ biosynthesis rate.

  19. Development of a diagnostic real-time polymerase chain reaction assay for the detection of invasive Haemophilus influenzae in clinical samples.

    PubMed

    Meyler, Kenneth L; Meehan, Mary; Bennett, Desiree; Cunney, Robert; Cafferkey, Mary

    2012-12-01

    Since the introduction of the Haemophilus influenzae serotype b vaccine, invasive H. influenzae disease has become dominated by nontypeable (NT) strains. Several widely used molecular diagnostic methods have been shown to lack sensitivity or specificity in the detection of some of these strains. Novel real-time assays targeting the fucK, licA, and ompP2 genes were developed and evaluated. The fucK assay detected all strains of H. influenzae tested (n = 116) and had an analytical sensitivity of 10 genome copies/polymerase chain reaction (PCR). This assay detected both serotype b and NT H. influenzae in 12 previously positive specimens (culture and/or bexA PCR) and also detected H. influenzae in a further 5 of 883 culture-negative blood and cerebrospinal fluid (CSF) samples. The fucK assay has excellent potential as a diagnostic test for detection of typeable and nontypeable strains of invasive H. influenzae in clinical samples of blood and CSF. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Dose-specific efficacy of Haemophilus influenzae type b conjugate vaccines: a systematic review and meta-analysis of controlled clinical trials

    PubMed Central

    GRIFFITHS, U. K.; CLARK, A.; GESSNER, B.; MINERS, A.; SANDERSON, C.; SEDYANINGSIH, E. R.; MULHOLLAND, K. E.

    2012-01-01

    SUMMARY Global coverage of infant Haemophilus influenzae type b (Hib) vaccination has increased considerably during the past decade, partly due to GAVI Alliance donations of the vaccine to low-income countries. In settings where large numbers of children receive only one or two vaccine doses rather than the recommended three doses, dose-specific efficacy estimates are needed to predict impact. The objective of this meta-analysis is to determine Hib vaccine efficacy against different clinical outcomes after receiving one, two or three doses of vaccine. Studies were eligible for inclusion if a prospective, controlled design had been used to evaluate commercially available Hib conjugate vaccines. Eight studies were included. Pooled vaccine efficacies against invasive Hib disease after one, two or three doses of vaccine were 59%, 92% and 93%, respectively. The meta-analysis provides robust estimates for use in decision-analytical models designed to predict the impact of Hib vaccine. PMID:22583474

  1. Development of a Multiplex PCR Assay for Rapid Molecular Serotyping of Haemophilus parasuis

    PubMed Central

    Peters, Sarah E.; Wang, Jinhong; Hernandez-Garcia, Juan; Weinert, Lucy A.; Luan, Shi-Lu; Chaudhuri, Roy R.; Angen, Øystein; Aragon, Virginia; Williamson, Susanna M.; Langford, Paul R.; Rycroft, Andrew N.; Wren, Brendan W.; Maskell, Duncan J.; Tucker, Alexander W.

    2015-01-01

    Haemophilus parasuis causes Glässer's disease and pneumonia in pigs. Indirect hemagglutination (IHA) is typically used to serotype this bacterium, distinguishing 15 serovars with some nontypeable isolates. The capsule loci of the 15 reference strains have been annotated, and significant genetic variation was identified between serovars, with the exception of serovars 5 and 12. A capsule locus and in silico serovar were identified for all but two nontypeable isolates in our collection of >200 isolates. Here, we describe the development of a multiplex PCR, based on variation within the capsule loci of the 15 serovars of H. parasuis, for rapid molecular serotyping. The multiplex PCR (mPCR) distinguished between all previously described serovars except 5 and 12, which were detected by the same pair of primers. The detection limit of the mPCR was 4.29 × 105 ng/μl bacterial genomic DNA, and high specificity was indicated by the absence of reactivity against closely related commensal Pasteurellaceae and other bacterial pathogens of pigs. A subset of 150 isolates from a previously sequenced H. parasuis collection was used to validate the mPCR with 100% accuracy compared to the in silico results. In addition, the two in silico-nontypeable isolates were typeable using the mPCR. A further 84 isolates were analyzed by mPCR and compared to the IHA serotyping results with 90% concordance (excluding those that were nontypeable by IHA). The mPCR was faster, more sensitive, and more specific than IHA, enabling the differentiation of 14 of the 15 serovars of H. parasuis. PMID:26424843

  2. Increase of β-Lactam-Resistant Invasive Haemophilus influenzae in Sweden, 1997 to 2010

    PubMed Central

    Resman, Fredrik; Ristovski, Mikael; Forsgren, Arne; Kaijser, Bertil; Kronvall, Göran; Medstrand, Patrik; Melander, Eva; Odenholt, Inga

    2012-01-01

    The proportions of Haemophilus influenzae resistant to ampicillin and other β-lactam antibiotics have been low in Sweden compared to other countries in the Western world. However, a near-doubled proportion of nasopharyngeal Swedish H. influenzae isolates with resistance to β-lactams has been observed in the last decade. In the present study, the epidemiology and mechanisms of antimicrobial resistance of H. influenzae isolates from blood and cerebrospinal fluid in southern Sweden from 1997 to 2010 (n = 465) were studied. Antimicrobial susceptibility testing was performed using disk diffusion, and isolates with resistance to any tested β-lactam were further analyzed in detail. We identified a significantly increased (P = 0.03) proportion of β-lactam-resistant invasive H. influenzae during the study period, which was mainly attributed to a significant recent increase of β-lactamase-negative β-lactam-resistant isolates (P = 0.04). Furthermore, invasive β-lactamase-negative β-lactam-resistant H. influenzae isolates from 2007 and onwards were found in higher proportions than the corresponding proportions of nasopharyngeal isolates in a national survey. Multiple-locus sequence typing (MLST) of this group of isolates did not completely separate isolates with different resistance phenotypes. However, one cluster of β-lactamase-negative ampicillin-resistant (BLNAR) isolates was identified, and it included isolates from all geographical areas. A truncated variant of a β-lactamase gene with a promoter deletion, blaTEM-1-PΔ dominated among the β-lactamase-positive H. influenzae isolates. Our results show that the proportions of β-lactam-resistant invasive H. influenzae have increased in Sweden in the last decade. PMID:22687505

  3. Divergent Mechanisms for Passive Pneumococcal Resistance to β-Lactam Antibiotics in the Presence of Haemophilus influenzae

    PubMed Central

    Weimer, Kristin E.D.; Juneau, Richard A.; Murrah, Kyle A.; Pang, Bing; Armbruster, Chelsie E.; Richardson, Stephen H.

    2011-01-01

    Background. Otitis media, for which antibiotic treatment failure is increasingly common, is a leading pediatric public health problem. Methods. In vitro and in vivo studies using the chinchilla model of otitis media were performed using a β-lactamase-producing strain of nontypeable Haemophilus influenzae (NTHi 86-028NP) and an isogenic mutant deficient in β-lactamase production (NTHi 86-028NP bla) to define the roles of biofilm formation and β-lactamase production in antibiotic resistance. Coinfection studies were done with Streptococcus pneumoniae to determine if NTHi provides passive protection by means of β-lactamase production, biofilm formation, or both. Results. NTHi 86-028NP bla was resistant to amoxicillin killing in biofilm studies in vitro; however, it was cleared by amoxicillin treatment in vivo, whereas NTHi 86-028NP was unaffected in either system. NTHi 86-028NP protected pneumococcus in vivo in both the effusion fluid and bullar homogenate. NTHi 86-028NP bla and pneumococcus were both recovered from the surface-associated bacteria of amoxicillin-treated animals; only NTHi 86-028NP bla was recovered from effusion. Conclusions. Based on these studies, we conclude that NTHi provides passive protection for S. pneumoniae in vivo through 2 distinct mechanisms: production of β-lactamase and formation of biofilm communities. PMID:21220774

  4. Divergent mechanisms for passive pneumococcal resistance to β-lactam antibiotics in the presence of Haemophilus influenzae.

    PubMed

    Weimer, Kristin E D; Juneau, Richard A; Murrah, Kyle A; Pang, Bing; Armbruster, Chelsie E; Richardson, Stephen H; Swords, W Edward

    2011-02-15

    Otitis media, for which antibiotic treatment failure is increasingly common, is a leading pediatric public health problem. In vitro and in vivo studies using the chinchilla model of otitis media were performed using a β-lactamase-producing strain of nontypeable Haemophilus influenzae (NTHi 86-028NP) and an isogenic mutant deficient in β-lactamase production (NTHi 86-028NP bla) to define the roles of biofilm formation and β-lactamase production in antibiotic resistance. Coinfection studies were done with Streptococcus pneumoniae to determine if NTHi provides passive protection by means of β-lactamase production, biofilm formation, or both. NTHi 86-028NP bla was resistant to amoxicillin killing in biofilm studies in vitro; however, it was cleared by amoxicillin treatment in vivo, whereas NTHi 86-028NP was unaffected in either system. NTHi 86-028NP protected pneumococcus in vivo in both the effusion fluid and bullar homogenate. NTHi 86-028NP bla and pneumococcus were both recovered from the surface-associated bacteria of amoxicillin-treated animals; only NTHi 86-028NP bla was recovered from effusion. Based on these studies, we conclude that NTHi provides passive protection for S. pneumoniae in vivo through 2 distinct mechanisms: production of β-lactamase and formation of biofilm communities.

  5. PnuC and the utilization of the nicotinamide riboside analog 3-aminopyridine in Haemophilus influenzae.

    PubMed

    Sauer, Elizabeta; Merdanovic, Melisa; Mortimer, Anne Price; Bringmann, Gerhard; Reidl, Joachim

    2004-12-01

    The utilization pathway for the uptake of NAD and nicotinamide riboside was previously characterized for Haemophilus influenzae. We now report on the cellular location, topology, and substrate specificity of PnuC. pnuC of H. influenzae is only distantly related to pnuC of Escherichia coli and Salmonella enterica serovar Typhimurium. When E. coli PnuC was expressed in an H. influenzae pnuC mutant, it was able to take up only nicotinamide riboside and not nicotinamide mononucleotide. Therefore, we postulated that PnuC transporters in general possess specificity for nicotinamide riboside. Earlier studies showed that 3-aminopyridine derivatives (e.g., 3-aminopyridine adenine dinucleotide) are inhibitory for H. influenzae growth. By testing characterized strains with mutations in the NAD utilization pathway, we show that 3-aminopyridine riboside is inhibitory to H. influenzae and is taken up by the NAD-processing and nicotinamide riboside route. 3-Aminopyridine riboside is utilized effectively in a pnuC+ background. In addition, we demonstrate that 3-aminopyridine adenine dinucleotide resynthesis is produced by NadR. 3-Aminopyridine riboside-resistant H. influenzae isolates were characterized, and mutations in nadR could be detected. We also tested other species of the family Pasteurellaceae, Pasteurella multocida and Actinobacillus actinomycetemcomitans, and found that 3-aminopyridine riboside does not act as a growth inhibitor; hence, 3-aminopyridine riboside represents an anti-infective agent with a very narrow host range.

  6. [Impact of vaccination on admissions for Haemophilus influenzae b meningitis from 2004 to 2008 in Bobo Dioulasso, Burkina Faso].

    PubMed

    Kaboré, N F; Poda, G E A; Barro, M; Cessouma, R; Héma, A; Ouedraogo, A S; Sawadogo, A B; Nacro, B

    2012-01-01

    Vaccination against Haemophilus influenzae type b was introduced in Burkina Faso on 1st January 2006. This study thus sought to determine the impact of the first 30 months of vaccination on admissions for Hib meningitis in the department of pediatrics at the Sourô-Sanou University Hospital in Bobo Dioulasso. Retrospective study of children aged zero to 14 years hospitalized from 1st January 2004 to 30th June 2008 for acute bacterial meningitis (laboratory-confirmed). During the study period, 416 children were admitted for acute bacterial meningitis. The bacterium isolated was identified in 386 cases and unidentified in 30 cases. Hib meningitis accounted for 42.3 % of the cases of identified bacterial meningitis before the introduction of the vaccine (2004 to 2005). This rate declined to 11.8 % for the first 30 months of vaccination (p < 0.001). No cases of Hib meningitis have been reported in the first half of 2008. Admissions for Hib meningitis in the Department of Pediatrics have practically disappeared two years after the introduction of the Hib vaccine into Burkina Faso's expanded program on immunization.

  7. Reevaluation of interpretive criteria for Haemophilus influenzae by using meropenem (10-microgram), imipenem (10-microgram), and ampicillin (2- and 10-microgram) disks.

    PubMed Central

    Zerva, L; Biedenbach, D J; Jones, R N

    1996-01-01

    A collection of 300 Haemophilus influenzae clinical strains was used to assess in vitro susceptibility to carbapenems (meropenem, imipenem) by MIC and disk diffusion methods and to compare disk diffusion test results with two potencies of ampicillin disks (2 and 10 micrograms). The isolates included ampicillin-susceptible or- intermediate (167 strains), beta-lactamase-positive (117 strains), and beta-lactamase-negative ampicillin-resistant (BLNAR; 16 strains) organisms. Disk diffusion testing was performed with 10-micrograms meropenem disks from two manufacturers. Meropenem was highly active against H. influenzae strains (MIC50, 0.06 microgram/ml; MIC90, 0.25 microgram/ml; MIC50 and MIC90, MICs at which 50 and 90%, respectively, of strains are inhibited) and was 8- to 16-fold more potent than imipenem (MIC50, 1 microgram/ml; MIC90, 2 micrograms/ml). Five non-imipenem-susceptible strains were identified (MIC, 8 micrograms/ml), but the disk diffusion test indicated susceptibility (zone diameters, 18 to 21 mm). MIC values of meropenem, doxycycline, ceftazidime, and ceftriaxone for BLNAR strains were two- to fourfold greater than those for other strains. The performance of both meropenem disks was comparable and considered acceptable. A single susceptible interpretive zone diameter of > or = 17 mm (MIC, < = or 4 micrograms/ml) was proposed for meropenem. Testing with the 2-micrograms ampicillin disk was preferred because of an excellent correlation between MIC values and zone diameters (r = 0.94) and superior interpretive accuracy with the susceptible criteria at > or = 17 mm (MIC, < or = 1 microgram/ml) and the resistant criteria at < or = 13 mm (MIC, > or = 4 micrograms/ml). Among the BLNAR strains tested, 81.3% were miscategorized as susceptible or intermediate when the 10-micrograms ampicillin disk was used, while the 2-micrograms disk produced only minor interpretive errors (12.5%). Use of these criteria for testing H. influenzae against meropenem and ampicillin

  8. [Bacterial meningitis caused by beta-lactamase-negative, ampicillin-resistant nontypeable Haemophilus influenzae in a 1-year-old girl: a case report].

    PubMed

    Abe, Katsuaki; Hoshino, Tadashi; Imuta, Naoko; Nishi, Junichiro; Ishiwada, Naruhiko

    2014-05-01

    We present herein the case report of bacterial meningitis caused by nontypeable Haemophilus influenzae (NTHi) in a 1-year-7-month-old girl with no medically significant history. NTHi from cerebrospinal fluid (CSF) was the beta-lactamase non-producing ampicillin resistant strain (BLNAR). Some beta-lactams were administrated, but fever was prolonged. Finally, rifampicin seemed to be effective. In NTHi, compared with H. influenzae type b (Hib), the prevalence of BLNAR is high. Hence, complicated cases may increase in the near future if the use of the Hib vaccine becomes widespread, and meningitis caused by NTHi increases. It may be necessary to consider combination therapy or use of non-beta-lactams that have a different antimicrobial mechanism from beta-lactams. PCR analysis revealed the possibility that the CSF isolate lacked the P5 protein gene. Though deficiency of P5 fimbriae is known to reduce the affinity of NTHi for the human respiratory epithelium, determining whether P5 deficient NTHi induced meningitis will require further study.

  9. A clinical trial examining the effect of increased total CRM(197) carrier protein dose on the antibody response to Haemophilus influenzae type b CRM(197) conjugate vaccine.

    PubMed

    Usonis, Vytautas; Bakasenas, Vytautas; Lockhart, Stephen; Baker, Sherryl; Gruber, William; Laudat, France

    2008-08-18

    CRM(197) is a carrier protein in certain conjugate vaccines. When multiple conjugate vaccines with the same carrier protein are administered simultaneously, reduced response to vaccines and/or antigens related to the carrier protein may occur. This study examined responses of infants who, in addition to diphtheria toxoid/tetanus toxoid/acellular pertussis vaccine (DTaP) received either diphtheria CRM(197)-based Haemophilus influenzae type b conjugate vaccine (HbOC) or HbOC and a diphtheria CRM(197)-based combination 9-valent pneumococcal conjugate vaccine/meningococcal group C conjugate vaccine. Administration of conjugate vaccines with CRM(197) carrier protein load >50 microg did not reduce response to CRM(197) conjugate vaccines or immunogenicity to immunologically cross-reactive diphtheria toxoid.

  10. In vitro and in vivo synergism between amoxicillin and clavulanic acid against ampicillin-resistant Haemophilus influenzae type b.

    PubMed Central

    Yogev, R; Melick, C; Kabat, W J

    1981-01-01

    Eight strans of ampicillin-resistant beta-lactamase-producing Haemophilus influenzae type b were studied in vitro for synergy between amoxicillin and clavulanic acid. The minimal inhibitory concentrations for amoxicillin alone were 6.25 to 12.5 microgram/ml, and for clavulanic acid alone they were 12.5 to 25 microgram/ml. However, seven of eight strains were inhibited by a combination of 0.36 microgram of amoxicillin and 0.36 microgram of clavulanic acid per ml. Infant rat models of bacteremia and meningitis were used to test the efficacy of amoxicillin and clavulanic acid alone and in combination upon four strains of ampicillin-resistant H. influenzae. Neither amoxicillin alone (27 animals) nor clavulanic acid alone (20 animals) sterilized the blood or cerebrospinal fluid of the animals. In contrast, 30 of 33 blood cultures and 29 of 33 cerebrospinal fluid cultures were sterile when a combination of the two drugs in the same dosages was used. The observed in vitro and in vivo synergism between amoxicillin and clavulanic acid suggests that the combination may be effective therapy for invasive infections in humans caused by ampicillin-resistant H. influenzae type b. PMID:6973952

  11. Nonencapsulated Streptococcus pneumoniae causes otitis media during single-species infection and during polymicrobial infection with nontypeable Haemophilus influenzae

    PubMed Central

    Murrah, Kyle A.; Pang, Bing; Richardson, Stephen; Perez, Antonia; Reimche, Jennifer; King, Lauren; Wren, John; Swords, W. Edward

    2014-01-01

    Streptococcus pneumoniae strains lacking capsular polysaccharide have been increasingly reported in carriage and disease contexts. Since most cases of otitis media involve more than one bacterial species, we aimed to determine the capacity of a nonencapsulated S. pneumoniae clinical isolate to induce disease in the context of a single-species infection and as a polymicrobial infection with nontypeable Haemophilus influenzae. Using the chinchilla model of otitis media, we found that nonencapsulated S. pneumoniae colonizes the nasopharynx following intranasal inoculation, but does not readily ascend into the middle ear. However, when we inoculated nonencapsulated S. pneumoniae directly into the middle ear, the bacteria persisted for two weeks post-inoculation and induced symptoms consistent with chronic otitis media. During coinfection with nontypeable H. influenzae, both species persisted for one week and induced polymicrobial otitis media. We also observed that nontypeable H. influenzae conferred passive protection from killing by amoxicillin upon S. pneumoniae from within polymicrobial biofilms in vitro. Therefore, based on these results, we conclude that nonencapsulated pneumococci are a potential causative agent of chronic/recurrent otitis media, and can also cause mutualistic infection with other opportunists, which could complicate treatment outcomes. PMID:26014114

  12. Seventeen Sxy-dependent cyclic AMP receptor protein site-regulated genes are needed for natural transformation in Haemophilus influenzae.

    PubMed

    Sinha, Sunita; Mell, Joshua C; Redfield, Rosemary J

    2012-10-01

    Natural competence is the ability of bacteria to actively take up extracellular DNA. This DNA can recombine with the host chromosome, transforming the host cell and altering its genotype. In Haemophilus influenzae, natural competence is induced by energy starvation and the depletion of nucleotide pools. This induces a 26-gene competence regulon (Sxy-dependent cyclic AMP receptor protein [CRP-S] regulon) whose expression is controlled by two regulators, CRP and Sxy. The role of most of the CRP-S genes in DNA uptake and transformation is not known. We have therefore created in-frame deletions of each CRP-S gene and studied their competence phenotypes. All but one gene (ssb) could be deleted. Although none of the remaining CRP-S genes were required for growth in rich medium or survival under starvation conditions, DNA uptake and transformation were abolished or reduced in most of the mutants. Seventeen genes were absolutely required for transformation, with 14 of these genes being specifically required for the assembly and function of the type IV pilus DNA uptake machinery. Only five genes were dispensable for both competence and transformation. This is the first competence regulon for which all genes have been mutationally characterized.

  13. Prevention and control of haemophilus influenzae type b disease: recommendations of the advisory committee on immunization practices (ACIP).

    PubMed

    Briere, Elizabeth C; Rubin, Lorry; Moro, Pedro L; Cohn, Amanda; Clark, Thomas; Messonnier, Nancy

    2014-02-28

    This report compiles and summarizes all recommendations from CDC's Advisory Committee on Immunization Practices (ACIP) regarding prevention and control of Haemophilus influenzae type b (Hib) disease in the United States. As a comprehensive summary of previously published recommendations, this report does not contain any new recommendations; it is intended for use by clinicians, public health officials, vaccination providers, and immunization program personnel as a resource. ACIP recommends routine vaccination with a licensed conjugate Hib vaccine for infants aged 2 through 6 months (2 or 3 doses, depending on vaccine product) with a booster dose at age 12 through 15 months. ACIP also recommends vaccination for certain persons at increased risk for Hib disease (i.e., persons who have early component complement deficiencies, immunoglobulin deficiency, anatomic or functional asplenia, or HIV infection; recipients of hematopoietic stem cell transplant; and recipients of chemotherapy or radiation therapy for malignant neoplasms). This report summarizes current information on Hib epidemiology in the United States and describes Hib vaccines licensed for use in the United States. Guidelines for antimicrobial chemoprophylaxis of contacts of persons with Hib disease also are provided.

  14. Coupling of NAD+ Biosynthesis and Nicotinamide Ribosyl Transport: Characterization of NadR Ribonucleotide Kinase Mutants of Haemophilus influenzae

    PubMed Central

    Merdanovic, Melisa; Sauer, Elizabeta; Reidl, Joachim

    2005-01-01

    Previously, we characterized a pathway necessary for the processing of NAD+ and for uptake of nicotinamide riboside (NR) in Haemophilus influenzae. Here we report on the role of NadR, which is essential for NAD+ utilization in this organism. Different NadR variants with a deleted ribonucleotide kinase domain or with a single amino acid change were characterized in vitro and in vivo with respect to cell viability, ribonucleotide kinase activity, and NR transport. The ribonucleotide kinase mutants were viable only in a nadV+ (nicotinamide phosphoribosyltransferase) background, indicating that the ribonucleotide kinase domain is essential for cell viability in H. influenzae. Mutations located in the Walker A and B motifs and the LID region resulted in deficiencies in both NR phosphorylation and NR uptake. The ribonucleotide kinase function of NadR was found to be feedback controlled by NAD+ under in vitro conditions and by NAD+ utilization in vivo. Taken together, our data demonstrate that the NR phosphorylation step is essential for both NR uptake across the inner membrane and NAD+ synthesis and is also involved in controlling the NAD+ biosynthesis rate. PMID:15968050

  15. Dual orientation of the outer membrane lipoprotein P6 of nontypeable haemophilus influenzae.

    PubMed

    Michel, Lea Vacca; Snyder, Joy; Schmidt, Rachel; Milillo, Jennifer; Grimaldi, Kyle; Kalmeta, Breanna; Khan, M Nadeem; Sharma, Sharad; Wright, Leslie Kate; Pichichero, Michael E

    2013-07-01

    The majority of outer membrane (OM) lipoproteins in Gram-negative bacteria are tethered to the membrane via an attached lipid moiety and oriented facing in toward the periplasmic space; a few lipoproteins have been shown to be surface exposed. The outer membrane lipoprotein P6 from the Gram-negative pathogenic bacterium nontypeable Haemophilus influenzae (NTHi) is surface exposed and a leading vaccine candidate for prevention of NTHi infections. However, we recently found that P6 is not a transmembrane protein as previously thought (L. V. Michel, B. Kalmeta, M. McCreary, J. Snyder, P. Craig, M. E. Pichichero, Vaccine 29:1624-1627, 2011). Here we pursued studies to show that P6 has a dual orientation, existing infrequently as surface exposed and predominantly as internally oriented toward the periplasmic space. Flow cytometry using three monoclonal antibodies with specificity for P6 showed surface staining of whole NTHi cells. Confocal microscopy imaging confirmed that antibodies targeted surface-exposed P6 of intact NTHi cells and not internal P6 in membrane-compromised or dead cells. Western blots of two wild-type NTHi strains and a mutant NTHi strain that does not express P6 showed that P6 antibodies do not detect a promiscuous epitope on NTHi. Depletion of targets to nonlipidated P6 significantly decreased bactericidal activity of human serum. Protease digestion of surface-exposed P6 demonstrated that P6 is predominantly internally localized in a manner similar to its homologue Pal in Escherichia coli. We conclude that P6 of NTHi is likely inserted into the OM in two distinct orientations, with the predominant orientation facing in toward the periplasm.

  16. Clinical characteristics of Haemophilus influenzae meningitis in Denmark in the post-vaccination era.

    PubMed

    Pedersen, T I; Howitz, M; Ostergaard, C

    2010-05-01

    The introduction of Haemophilus influenzae type b (Hib) vaccine into the Danish childhood vaccination programme in 1993 may have influenced the epidemiology of H. influenzae meningitis (i.e. increasing frequency of other non-vaccine types; presentation in other age groups). Based on nationwide registration, clinical information and laboratory findings were collected from all 65 confirmed cases of H. influenzae meningitis during the period 1994-2005. Twenty-nine patients (45%) were <13 years old [median 15 months (range 0-147)], and 36 patients (55%) were >24 years old [median 62 years (range 25-96)]. Hib accounted for 31% (20/65) of the cases, and significantly more children were infected with Hib compared with adults [53% (16/29) vs. 11% (4/36), respectively, p 0.0003]. Overall, 38% of cases had an otogenic focus and this was thus the most frequent primary focus of infection. Among children infected with Hib, two cases (13%) were identified as true vaccine failures. Six patients (9%) died; one premature infant infected with serotype f and five adults (age 83-96 years) with non-typeable H. influenzae. Hearing loss was reported in 16% of the surviving children and in 10% of the surviving adults. The presence of a lung focus was an independent prognostic factor for an unfavourable outcome (p 0.03). In conclusion, meningitis caused by Hib has been infrequent in Denmark after introduction of the Hib vaccine in the childhood vaccination programme, and no increase in meningitis cases due to non-b type H. influenzae has been observed. Cases with H. influenzae meningitis frequently had an otogenic focus, with low risk of an unfavourable outcome.

  17. Biofilm formation in Haemophilus parasuis: relationship with antibiotic resistance, serotype and genetic typing.

    PubMed

    Zhang, Jianmin; Xu, Chenggang; Shen, Haiyan; Li, Jingyi; Guo, Lili; Cao, Guojie; Feng, Saixiang; Liao, Ming

    2014-10-01

    Biofilms are surface-associated microbial communities, which are encased in self-synthesized extracellular environment. Biofilm formation may trigger drug resistance and inflammation, resulting in persistent infections. Haemophilus parasuis is the etiological agent of a systemic disease, Glässer's disease, characterized by fibrinous polyserositis, arthritis and meningitis in pigs. The purpose of this study was to examine the correlation between biofilm and antibiotic resistance among the clinical isolates of H. parasuis. In the present study, we tested biofilm-forming ability of 110 H. parasuis isolates from various farms using polystyrene microtiter plate assays. Seventy-three isolates of H. parasuis (66.4%) showed biofilm formation and most of them performed weak biofilm-forming ability (38/73). All isolates were tested for antimicrobial susceptibility to 18 antimicrobial agents by the broth microdilution method. H. parasuis isolates showed very high resistance (>90%) to sulfanilamide, nalidixic acid, and trimethoprim. Resistance to eight antibiotics such as penicillin (41.1% vs 8.1%), ampicillin (31.5% vs 8.1%), amoxicillin (28.8% vs 5.4%), gentamicin (46.6% vs 24.3%), cefazolin (19.2% vs 2.7%), doxycycline (19.2% vs 8.1%), cefotaxime (11% vs 2.7%), and cefaclor (13.7% vs 5.4%) was comparatively higher among biofilm producers than non-biofilm producers. Pulsed-field gel electrophoresis (PFGE) analyses could distinguish various isolates. Our data indicated that H. parasuis field isolates were able to form biofilms in vitro. In addition, biofilm positive strains had positive correlation with resistance to β-lactams antibiotics. Thus, biofilm formation may play important roles during H. parasuis infections. Copyright © 2014. Published by Elsevier Ltd.

  18. Invasive Haemophilus influenzae disease in the vaccine era in Rio de Janeiro, Brazil.

    PubMed

    Tuyama, Mari; Corrêa-Antônio, Jessica; Schlackman, Jessica; Marsh, Jane W; Rebelo, Maria C; Cerqueira, Elaine O; Nehab, Márcio; Kegele, Fabíola; Carmo, Getúlio F; Thielmann, Dominique Ca; Barroso, Paulo F; Harrison, Lee H; Barroso, David E

    2017-03-01

    Haemophilus influenzae (Hi) serotype b (Hib) conjugate vaccine was incorporated into the infant immunisation schedule in Brazil in 1999, where Hib was one of the major etiologic sources of community-acquired bacterial meningitis. The purpose of this study is to describe the molecular epidemiology of invasive Hi disease in Rio de Janeiro state, Brazil, before and after vaccine introduction. Surveillance data from 1986 to 2014 were analysed. Hi isolates recovered from cerebrospinal fluid (CSF) or blood from 1993 to 2014 were serotyped by slide agglutination, genotyped by multilocus sequence typing (MLST), and the capsule type evaluation, differentiation of serologically non-typeable isolates, and characterisation of the capsule (cap) locus was done by polymerase chain reaction. Antimicrobial susceptibility testing was performed using E-test. From 1986 to 1999 and from 2000 to 2014, 2580 and 197 (42% without serotype information) confirmed cases were reported, respectively. The case fatality rate was 17% and did not correlate with the strain. Hib and b- variant isolates belonged to ST-6, whereas serotype a isolates belonged to the ST-23 clonal complex. Serotype a appeared to emerge during the 2000s. Non-encapsulated isolates were non-clonal and distinct from the encapsulated isolates. Ampicillin-resistant isolates were either of serotype b or were non-encapsulated, and all of them were β-lactamase-positive but amoxicillin-clavulanic acid susceptible. Although Hi meningitis became a relatively rare disease in Rio de Janeiro after the introduction of the Hib conjugate vaccine, the isolates recovered from patients have become more diverse. These results indicate the need to implement an enhanced surveillance system to continue monitoring the impact of the Hib conjugate vaccine.

  19. Relationship between Azithromycin Susceptibility and Administration Efficacy for Nontypeable Haemophilus influenzae Respiratory Infection

    PubMed Central

    Euba, Begoña; Moleres, Javier; Viadas, Cristina; Barberán, Montserrat; Caballero, Lucía; Grilló, María-Jesús; Bengoechea, José Antonio; de-Torres, Juan Pablo; Liñares, Josefina; Leiva, José

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHI) is an opportunistic pathogen that is an important cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). COPD is an inflammatory disease of the airways, and exacerbations are acute inflammatory events superimposed on this background of chronic inflammation. Azithromycin (AZM) is a macrolide antibiotic with antibacterial and anti-inflammatory properties and a clinically proven potential for AECOPD prevention and management. Relationships between AZM efficacy and resistance by NTHI and between bactericidal and immunomodulatory effects on NTHI respiratory infection have not been addressed. In this study, we employed two pathogenic NTHI strains with different AZM susceptibilities (NTHI 375 [AZM susceptible] and NTHI 353 [AZM resistant]) to evaluate the prophylactic and therapeutic effects of AZM on the NTHI-host interplay. At the cellular level, AZM was bactericidal toward intracellular NTHI inside alveolar and bronchial epithelia and alveolar macrophages, and it enhanced NTHI phagocytosis by the latter cell type. These effects correlated with the strain MIC of AZM and the antibiotic dose. Additionally, the effect of AZM on NTHI infection was assessed in a mouse model of pulmonary infection. AZM showed both preventive and therapeutic efficacies by lowering NTHI 375 bacterial counts in lungs and bronchoalveolar lavage fluid (BALF) and by reducing histopathological inflammatory lesions in the upper and lower airways of mice. Conversely, AZM did not reduce bacterial loads in animals infected with NTHI 353, in which case a milder anti-inflammatory effect was also observed. Together, the results of this work link the bactericidal and anti-inflammatory effects of AZM and frame the efficacy of this antibiotic against NTHI respiratory infection. PMID:25712355

  20. DNA aptamers for the detection of Haemophilus influenzae type b by cell SELEX.

    PubMed

    Bitaraf, F S; Rasooli, I; Mousavi Gargari, S L

    2016-03-01

    Haemophilus influenzae type b (Hib) causes acute bacterial meningitis (ABM) in children, with a mortality rate of about 3-6 % of the affected patients. ABM can lead to death during a period of hours to several days and, hence, rapid and early detection of the infection is crucial. Aptamers, the short single-stranded DNA or RNA with high affinity to target molecules, are selected by a high-flux screening technique known as in vitro screening and systematic evolution of ligands by exponential enrichment technology (SELEX). In this study, whole-cell SELEX was applied for the selection of target-specific aptamers with high affinity to Hib. ssDNA aptamers prepared by lambda exonuclease were incubated with the target cells (Hib). The aptameric binding rate to Hib was characterized for binding affinity after seven SELEX rounds by flow cytometry. The aptamers with higher binding affinity were cloned. Four of 68 aptamer clones were selected for sequencing. The dissociation constant (Kd) of the high-affinity aptamer clones 45 and 63 were 47.10 and 28.46 pM, respectively. These aptamers did not bind to other bacterial species, including the seven meningitis-causing bacteria. They showed distinct affinity to various H. influenzae strains only. These aptamers showed the highest affinity to Hib and the lowest affinity to H. influenzae type c and to other meningitis-causing bacteria. Clone 63 could detect Hib in patients' cerebrospinal fluid (CSF) samples at 60 colony-forming units (CFU)/mL. The results indicate applicability of the aptamers for rapid and early detection of infections brought about by Hib.

  1. Characterization of Chinese Haemophilus parasuis Isolates by Traditional Serotyping and Molecular Serotyping Methods

    PubMed Central

    Ma, Lina; Wang, Liyan; Chu, Yuefeng; Li, Xuerui; Cui, Yujun; Chen, Shengli; Zhou, Jianhua; Li, Chunling; Lu, Zhongxin; Liu, Jixing; Liu, Yongsheng

    2016-01-01

    Haemophilus parasuis is classified mainly through serotyping, but traditional serotyping always yields non-typable (NT) strains and unreliable results via cross-reactions. Here, we surveyed the serotype prevalence of Chinese H. parasuis isolates using traditional serotyping (gel immuno-diffusion test, GID) and molecular serotyping (multiplex PCR, mPCR). We also investigated why discrepant results between these methods were obtained, and investigated mPCR failure through whole-genome sequencing. Of the 100 isolate tested, 73 (73%) and 93 (93%) were serotyped by the GID test and mPCR, respectively, with a concordance rate of 66% (66/100). Additionally, mPCR reduced the number of NT isolates from 27 (27%) for the GID testing, to seven (7%). Eleven isolates were sequenced, including nine serotype-discrepant isolates from mPCR and GID typing (excluding strains that were NT by GID only) and two NT isolates from both methods, and their in silico serotypes were obtained from genome sequencing based on their capsule loci. The mPCR results were supported by the in silico serotyping of the seven serotype-discrepant isolates. The discrepant results and NT isolates determined by mPCR were attributed to deletions and unknown sequences in the serotype-specific region of each capsule locus. Compared with previous investigations, this study found a similar predominant serotype profile, but a different prevalence frequency for H. parasuis, and the five most prevalent serotypes or strain groups were serotypes 5, 4, NT, 7 and 13 for mPCR, and serotypes 5, NT, 4, 7 and 13/10/14 for GID. Additionally, serotype 7 was recognized as a principal serotype in this work. PMID:28005999

  2. A chalcone with potent inhibiting activity against biofilm formation by nontypeable Haemophilus influenzae.

    PubMed

    Kunthalert, Duangkamol; Baothong, Sudarat; Khetkam, Pichit; Chokchaisiri, Suwadee; Suksamrarn, Apichart

    2014-10-01

    Nontypeable Haemophilus influenzae (NTHi), an important human respiratory pathogen, frequently causes biofilm infections. Currently, resistance of bacteria within the biofilm to conventional antimicrobials poses a major obstacle to effective medical treatment on a global scale. Novel agents that are effective against NTHi biofilm are therefore urgently required. In this study, a series of natural and synthetic chalcones with various chemical substituents were evaluated in vitro for their antibiofilm activities against strong biofilm-forming strains of NTHi. Of the test chalcones, 3-hydroxychalcone (chalcone 8) exhibited the most potent inhibitory activity, its mean minimum biofilm inhibitory concentration (MBIC50 ) being 16 μg/mL (71.35 μM), or approximately sixfold more active than the reference drug, azithromycin (MBIC50 419.68 μM). The inhibitory activity of chalcone 8, which is a chemically modified chalcone, appeared to be superior to those of the natural chalcones tested. Significantly, chalcone 8 inhibited biofilm formation by all studied NTHi strains, indicating that the antibiofilm activities of this compound occur across multiple strong-biofilm forming NTHi isolates of different clinical origins. According to antimicrobial and growth curve assays, chalcone 8 at concentrations that decreased biofilm formation did not affect growth of NTHi, suggesting the biofilm inhibitory effect of chalcone 8 is non-antimicrobial. In terms of structure-activity relationship, the possible substituent on the chalcone backbone required for antibiofilm activity is discussed. These findings indicate that 3-hydroxychalcone (chalcone 8) has powerful antibiofilm activity and suggest the potential application of chalcone 8 as a new therapeutic agent for control of NTHi biofilm-associated infections. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.

  3. Sialylation of lipooligosaccharides is dispensable for the virulence of Haemophilus ducreyi in humans.

    PubMed

    Spinola, Stanley M; Li, Wei; Fortney, Kate R; Janowicz, Diane M; Zwickl, Beth; Katz, Barry P; Munson, Robert S

    2012-02-01

    Sialylated glycoconjugates on the surfaces of mammalian cells play important roles in intercellular communication and self-recognition. The sialic acid preferentially expressed in human tissues is N-acetylneuraminic acid (Neu5Ac). In a process called molecular mimicry, many bacterial pathogens decorate their cell surface glycolipids with Neu5Ac. Incorporation of Neu5Ac into bacterial glycolipids promotes bacterial interactions with host cell receptors called Siglecs. These interactions affect bacterial adherence, resistance to serum killing and phagocytosis, and innate immune responses. Haemophilus ducreyi, the etiologic agent of chancroid, expresses lipooligosaccharides (LOS) that are highly sialylated. However, an H. ducreyi sialyltransferase (lst) mutant, whose LOS contain reduced levels of Neu5Ac, is fully virulent in human volunteers. Recently, a second sialyltransferase gene (Hd0053) was discovered in H. ducreyi, raising the possibility that Hd0053 compensated for the loss of lst during human infection. CMP-Neu5Ac is the obligate nucleotide sugar donor for all bacterial sialyltransferases; LOS derived from an H. ducreyi CMP-Neu5Ac synthetase (neuA) mutant has no detectable Neu5Ac. Here, we compared an H. ducreyi neuA mutant to its wild-type parent in several models of pathogenesis. In human inoculation experiments, the neuA mutant formed papules and pustules at rates that were no different than those of its parent. When grown in media with and without Neu5Ac supplementation, the neuA mutant and its parent had similar phenotypes in bactericidal, macrophage uptake, and dendritic cell activation assays. Although we cannot preclude a contribution of LOS sialylation to ulcerative disease, these data strongly suggest that sialylation of LOS is dispensable for H. ducreyi pathogenesis in humans.

  4. Haemophilus influenzae OxyR: Characterization of Its Regulation, Regulon and Role in Fitness

    PubMed Central

    Whitby, Paul W.; Morton, Daniel J.; VanWagoner, Timothy M.; Seale, Thomas W.; Cole, Brett K.; Mussa, Huda J.; McGhee, Phillip A.; Bauer, Chee Yoon S.; Springer, Jennifer M.; Stull, Terrence L.

    2012-01-01

    To prevent damage by reactive oxygen species, many bacteria have evolved rapid detection and response systems, including the OxyR regulon. The OxyR system detects reactive oxygen and coordinates the expression of numerous defensive antioxidants. In many bacterial species the coordinated OxyR-regulated response is crucial for in vivo survival. Regulation of the OxyR regulon of Haemophilus influenzae was examined in vitro, and significant variation in the regulated genes of the OxyR regulon among strains of H. influenzae was observed. Quantitative PCR studies demonstrated a role for the OxyR-regulated peroxiredoxin/glutaredoxin as a mediator of the OxyR response, and also indicated OxyR self-regulation through a negative feedback loop. Analysis of transcript levels in H. influenzae samples derived from an animal model of otitis media demonstrated that the members of the OxyR regulon were actively upregulated within the chinchilla middle ear. H. influenzae mutants lacking the oxyR gene exhibited increased sensitivity to challenge with various peroxides. The impact of mutations in oxyR was assessed in various animal models of H. influenzae disease. In paired comparisons with the corresponding wild-type strains, the oxyR mutants were unaffected in both the chinchilla model of otitis media and an infant model of bacteremia. However, in weanling rats the oxyR mutant was significantly impaired compared to the wild-type strain. In contrast, in all three animal models when infected with a mixture of equal numbers of both wild-type and mutant strains the mutant strain was significantly out competed by the wild-type strain. These findings clearly establish a crucial role for OxyR in bacterial fitness. PMID:23226321

  5. Dual RNA-seq of Nontypeable Haemophilus influenzae and Host Cell Transcriptomes Reveals Novel Insights into Host-Pathogen Cross Talk.

    PubMed

    Baddal, Buket; Muzzi, Alessandro; Censini, Stefano; Calogero, Raffaele A; Torricelli, Giulia; Guidotti, Silvia; Taddei, Anna R; Covacci, Antonello; Pizza, Mariagrazia; Rappuoli, Rino; Soriani, Marco; Pezzicoli, Alfredo

    2015-11-17

    The ability to adhere and adapt to the human respiratory tract mucosa plays a pivotal role in the pathogenic lifestyle of nontypeable Haemophilus influenzae (NTHi). However, the temporal events associated with a successful colonization have not been fully characterized. In this study, by reconstituting the ciliated human bronchial epithelium in vitro, we monitored the global transcriptional changes in NTHi and infected mucosal epithelium simultaneously for up to 72 h by dual RNA sequencing. The initial stage of colonization was characterized by the binding of NTHi to ciliated cells. Temporal profiling of host mRNA signatures revealed significant dysregulation of the target cell cytoskeleton elicited by bacterial infection, with a profound effect on the intermediate filament network and junctional complexes. In response to environmental stimuli of the host epithelium, NTHi downregulated its central metabolism and increased the expression of transporters, indicating a change in the metabolic regime due to the availability of host substrates. Concurrently, the oxidative environment generated by infected cells instigated bacterial expression of stress-induced defense mechanisms, including the transport of exogenous glutathione and activation of the toxin-antitoxin system. The results of this analysis were validated by those of confocal microscopy, Western blotting, Bio-plex, and real-time quantitative reverse transcription-PCR (qRT-PCR). Notably, as part of our screening for novel signatures of infection, we identified a global profile of noncoding transcripts that are candidate small RNAs (sRNAs) regulated during human host infection in Haemophilus species. Our data, by providing a robust and comprehensive representation of the cross talk between the host and invading pathogen, provides important insights into NTHi pathogenesis and the development of efficacious preventive strategies. Simultaneous monitoring of infection-linked transcriptome alterations in an invading

  6. Efficacy of simulated cefditoren versus amoxicillin-clavulanate free concentrations in countering intrastrain ftsI gene diffusion in Haemophilus influenzae.

    PubMed

    González, Natalia; Aguilar, Lorenzo; Sevillano, David; Giménez, Maria-Jose; Alou, Luis; Cafini, Fabio; Torrico, Martha; López, Ana-Maria; Coronel, Pilar; Prieto, Jose

    2011-06-01

    This study explores the effects of cefditoren (CDN) versus amoxicillin-clavulanic acid (AMC) on the evolution (within a single strain) of total and recombined populations derived from intrastrain ftsI gene diffusion in β-lactamase-positive (BL⁺) and β-lactamase-negative (BL⁻) Haemophilus influenzae. DNA from β-lactamase-negative, ampicillin-resistant (BLNAR) isolates (DNA(BLNAR)) and from β-lactamase-positive, amoxicillin-clavulanate-resistant (BLPACR) (DNA(BLPACR)) isolates was extracted and added to a 10⁷-CFU/ml suspension of one BL⁺ strain (CDN MIC, 0.007 μg/ml; AMC MIC, 1 μg/ml) or one BL⁻ strain (CDN MIC, 0.015 μg/ml; AMC MIC, 0.5 μg/ml) in Haemophilus Test Medium (HTM). The mixture was incubated for 3 h and was then inoculated into a two-compartment computerized device simulating free concentrations of CDN (400 mg twice a day [b.i.d.]) or AMC (875 and 125 mg three times a day [t.i.d.]) in serum over 24 h. Controls were antibiotic-free simulations. Colony counts were performed; the total population and the recombined population were differentiated; and postsimulation MICs were determined. At time zero, the recombined population was 0.00095% of the total population. In controls, the BL⁻ and BL⁺ total populations and the BL⁻ recombined population increased (from ≈3 log₁₀ to 4.5 to 5 log₁₀), while the BL⁺ recombined population was maintained in simulations with DNA(BLPACR) and was decreased by ≈2 log₁₀ with DNA(BLNAR). CDN was bactericidal (percentage of the dosing interval for which experimental antibiotic concentrations exceeded the MIC [ft>MIC], >88%), and no recombined populations were detected from 4 h on. AMC was bactericidal against BL⁻ strains (ft>MIC, 74.0%) in DNA(BLNAR) and DNA(BLPACR) simulations, with a small final recombined population (MIC, 4 μg/ml; ft>MIC, 30.7%) in DNA(BLPACR) simulations. When AMC was used against the BL⁺ strain (in DNA(BLNAR) or DNA(BLPACR) simulations), the bacterial load was

  7. Comparative efficacy of several disinfectants in suspension and carrier tests against Haemophilus parasuis serovars 1 and 5.

    PubMed

    Rodríguez Ferri, E F; Martínez, S; Frandoloso, R; Yubero, S; Gutiérrez Martín, C B

    2010-06-01

    The comparative efficacy of 16 active compounds (including the most commonly used chemical groups) and 10 commercial formulations against Haemophilus parasuis serovars 1 and 5 was studied. These organisms were tested in suspension and carrier tests in the presence and absence of serum as representative of organic matter. Chloramine-T and half of the formulations from commercial sources (most of them including quaternary ammonium compounds) were effective in both in vitro tests, regardless of the presence or absence of organic load. All 26 disinfectants except for an iodophor (0.1% available iodine) resulted in at least 3-log(10) reduction in colony-forming units in suspension test, and most of them resulted in the maximal level of detection (>6-log(10) reduction). On the other hand, disinfectants were not as effective in carrier test as in suspension test, and the presence of serum considerably reduced the activities of most of the compounds tested, especially in carrier test. These results suggest the importance of selecting suitable disinfection for routine use on surfaces contaminated with H. parasuis, particularly when organic matter is present. Chloramine-T and formulations 2 and 7-10 are recommended for a complete inactivation of H. parasuis in swine herds. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Mapping the Laminin Receptor Binding Domains of Neisseria meningitidis PorA and Haemophilus influenzae OmpP2

    PubMed Central

    Mahdavi, Jafar; Oldfield, Neil J.; Wheldon, Lee M.; Wooldridge, Karl G.; Ala'Aldeen, Dlawer A. A.

    2012-01-01

    Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae are major bacterial agents of meningitis. They each bind the 37/67-kDa laminin receptor (LamR) via the surface protein adhesins: meningococcal PilQ and PorA, H. influenzae OmpP2 and pneumococcal CbpA. We have previously reported that a surface-exposed loop of the R2 domain of CbpA mediates LamR-binding. Here we have identified the LamR-binding regions of PorA and OmpP2. Using truncated recombinant proteins we show that binding is dependent on amino acids 171–240 and 91–99 of PorA and OmpP2, respectively, which are predicted to localize to the fourth and second surface-exposed loops, respectively, of these proteins. Synthetic peptides corresponding to the loops bound LamR and could block LamR-binding to bacterial ligands in a dose dependant manner. Meningococci expressing PorA lacking the apex of loop 4 and H. influenzae expressing OmpP2 lacking the apex of loop 2 showed significantly reduced LamR binding. Since both loops are hyper-variable, our data may suggest a molecular basis for the range of LamR-binding capabilities previously reported among different meningococcal and H. influenzae strains. PMID:23049988

  9. Mapping the laminin receptor binding domains of Neisseria meningitidis PorA and Haemophilus influenzae OmpP2.

    PubMed

    Abouseada, Noha M; Assafi, Mahde Saleh A; Mahdavi, Jafar; Oldfield, Neil J; Wheldon, Lee M; Wooldridge, Karl G; Ala'Aldeen, Dlawer A A

    2012-01-01

    Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae are major bacterial agents of meningitis. They each bind the 37/67-kDa laminin receptor (LamR) via the surface protein adhesins: meningococcal PilQ and PorA, H. influenzae OmpP2 and pneumococcal CbpA. We have previously reported that a surface-exposed loop of the R2 domain of CbpA mediates LamR-binding. Here we have identified the LamR-binding regions of PorA and OmpP2. Using truncated recombinant proteins we show that binding is dependent on amino acids 171-240 and 91-99 of PorA and OmpP2, respectively, which are predicted to localize to the fourth and second surface-exposed loops, respectively, of these proteins. Synthetic peptides corresponding to the loops bound LamR and could block LamR-binding to bacterial ligands in a dose dependant manner. Meningococci expressing PorA lacking the apex of loop 4 and H. influenzae expressing OmpP2 lacking the apex of loop 2 showed significantly reduced LamR binding. Since both loops are hyper-variable, our data may suggest a molecular basis for the range of LamR-binding capabilities previously reported among different meningococcal and H. influenzae strains.

  10. SapF-mediated heme-iron utilization enhances persistence and coordinates biofilm architecture of Haemophilus

    PubMed Central

    Vogel, Andrew R.; Szelestey, Blake R.; Raffel, Forrest K.; Sharpe, Samantha W.; Gearinger, Rachel L.; Justice, Sheryl S.; Mason, Kevin M.

    2012-01-01

    Non-typeable Haemophilus influenzae (NTHI) is a common commensal bacterium that resides in the human upper respiratory tract of healthy individuals. NTHI is also a known causative agent of multiple diseases including sinusitis, otitis media, as well as exacerbates disease severity of patients with cystic fibrosis and chronic obstructive pulmonary disease. We have previously shown that the Sap transporter mediates resistance to host antimicrobial peptides (AMPs) and import of the iron-containing compound heme. Here, we analyzed the contribution of the Sap structural ATPase protein, SapF, in these essential functions. In contrast to SapD, SapF was dispensable for NTHI survival when exposed to AMPs in vitro. SapF was responsible for heme utilization and recovery of depleted internal heme-iron stores. Further, a loss of SapF resulted in morphological plasticity and enhanced community development and biofilm architecture, suggesting the potential role of heme-iron availability in coordinating the complexity of NTHI biofilm architecture. SapF was required for colonization of the nasopharynx and acute infection of the middle ear, as SapF deficiency correlated with a statistically significant decrease in NTHI persistence in vivo. These data suggest that SapF is required for proper heme utilization which directly impacts NTHI survival. Thus, these studies further support a role for the Sap complex in the transport of multiple substrates and further defines substrate specificity for the two ATPase subunits. Given the multiple essential functions provided by the Sap transporter, this complex could prove to be an effective therapeutic target for the treatment of NTHI diseases. PMID:22919633

  11. Development and technology transfer of Haemophilus influenzae type b conjugate vaccines for developing countries.

    PubMed

    Beurret, Michel; Hamidi, Ahd; Kreeftenberg, Hans

    2012-07-13

    This paper describes the development of a Haemophilus influenzae type b (Hib) conjugate vaccine at the National Institute for Public Health and the Environment/Netherlands Vaccine Institute (RIVM/NVI, Bilthoven, The Netherlands), and the subsequent transfer of its production process to manufacturers in developing countries. In 1998, at the outset of the project, the majority of the world's children were not immunized against Hib because of the high price and limited supply of the conjugate vaccines, due partly to the fact that local manufacturers in developing countries did not master the Hib conjugate production technology. To address this problem, the RIVM/NVI has developed a robust Hib conjugate vaccine production process based on a proven model, and transferred this technology to several partners in India, Indonesia, Korea and China. As a result, emerging manufacturers in developing countries acquired modern technologies previously unavailable to them. This has in turn facilitated their approach to producing other conjugate vaccines. As an additional spin-off from the project, a World Health Organization (WHO) Hib quality control (QC) course was designed and conducted at the RIVM/NVI, resulting in an increased regulatory capacity for conjugate vaccines in developing countries at the National Regulatory Authority (NRA) level. For the local populations, this has translated into an increased and sustainable supply of affordable Hib conjugate-containing combination vaccines. During the course of this project, developing countries have demonstrated their ability to produce large quantities of high-quality modern vaccines after a successful transfer of the technology. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. First isolation of Haemophilus parasuis and other NAD-dependent Pasteurellaceae of swine from European wild boars.

    PubMed

    Olvera, A; Cerdà-Cuéllar, M; Mentaberre, G; Casas-Diaz, E; Lavin, S; Marco, I; Aragon, V

    2007-11-15

    Haemophilus parasuis is a colonizer of the upper respiratory tract of pigs and the etiological agent of Glässer's disease, which is characterized by a fibrinous polyserositis, meningitis and arthritis. Glässer's disease has never been reported in wild boar (Sus scrofa), although antibodies against H. parasuis have been detected. The goal of this study was to confirm the presence of this bacterium in wild boar by bacterial isolation and to compare the strains to H. parasuis from domesticated pigs. Therefore, nasal swabs from 42 hunted wild boars were processed for bacterial isolation and subsequent H. parasuis identification by specific PCR, biochemical tests and 16S rRNA gene sequencing. Two different strains of H. parasuis from two wild boars were isolated. These strains belonged to serotype 2 and were included by 16S rRNA gene sequencing and MLST analysis in a cluster with other H. parasuis strains of nasal origin from domestic pigs. During this study, Actinobacillus minor and Actinobacillus indolicus, which are NAD-dependent Pasteurellaceae closely related to H. parasuis, were also isolated. Our results indicate similarities in the respiratory microbiota of wild boars and domestic pigs, and although H. parasuis was isolated from wild boars, more studies are needed to determine if this could be a source of H. parasuis infection for domestic pigs.

  13. Follow-up of cases of Haemophilus influenzae type b meningitis to determine its long-term sequelae.

    PubMed

    Ahmed, A S M Nawshad Uddin; Khan, Naila Z; Hussain, Manzoor; Amin, M Ruhul; Hanif, Mohammed; Mahbub, Mustafa; El-Arifeen, Shams; Baqui, Abdullah H; Qazi, Shamim A; Saha, Samir K

    2013-07-01

    To measure physical and neurologic impact of Haemophilus influenzae type b (Hib) meningitis on surviving children through short- and long-term follow-up. Cases of Hib meningitis, diagnosed at a tertiary level pediatric hospital, were subjected to short- and long-term follow-up and compared with age, sex, and area of residence matched healthy controls. Follow-up assessments included thorough physical and neurodevelopmental assessments using a standardized protocol by a multidisciplinary team. Assessments of short-term follow-up cohort (n = 64) revealed hearing, vision, mental, and psychomotor deficits in 7.8%, 3%, 20%, and 25% of the cases, respectively. Deficits were 10%, 1.4%, 21%, and 25% in long-term follow-up cohort (n = 71), in that order. Mental and psychomotor deficits were found in 2% of the controls, none of whom had vision or hearing deficits. In addition to risk of death, Hib meningitis in children causes severe disabilities in survivors. These data facilitated a comprehensive understanding of the burden of Hib meningitis, specifically in developing countries where disabled children remain incapacitated because of lack of resources and facilities. The evidence generated from this study is expected to provide a compelling argument in favor of introduction and continuation of Hib conjugate vaccine in the national immunization program for children. Copyright © 2013. Published by Mosby, Inc.

  14. Impact of Haemophilus influenzae Type b conjugate vaccine in Mongolia: prospective population-based surveillance, 2002-2010.

    PubMed

    Scott, Susana; Altanseseg, Dorjpurev; Sodbayer, Demberelsuren; Nymadawa, Pagvajav; Bulgan, Davaadash; Mendsaikhan, Jamsran; Watt, James P; Slack, Mary P E; Carvalho, Maria G; Hajjeh, Rana; Edmond, Karen M

    2013-07-01

    Bacterial meningitis is associated with high mortality and long-term complications. This study assessed the impact of Haemophilus influenzae type b (Hib) conjugate vaccine on childhood bacterial meningitis in Ulaanbaatar, Mongolia. Prospective, active, population-based surveillance for suspected meningitis in children aged 2-59 months was conducted (February 2002-January 2011) in 6 hospitals. Clinical data, blood, and cerebrospinal fluid were collected. The impact of Hib conjugate vaccine was assessed by comparing Hib and all cause meningitis data in the 3 years preceding pentavalent conjugate vaccine implementation (2002-2004) with 3 years postimplementation (2008-2010). Five hundred eleven cases of suspected meningitis were identified from 2002-2011. Pentavalent conjugate vaccine coverage in December 2005 in Ulaanbaatar city was 97%. The proportion of suspected cases confirmed as Hib meningitis decreased from 25% (50/201) in the prevaccination era to 2% (4/193) in the postvaccination era (P < .0001). The annual incidence of Hib decreased from 28 cases per 100,000 children in 2002-2005 to 2 per 100,000 in 2008-2010 (P < .0001). This article demonstrates the marked impact of Hib conjugate vaccine introduction on meningitis in Mongolia. It is important to sustain this surveillance system to monitor the long-term impact of Hib conjugate vaccine, as well as other interventions such as pneumococcal and meningococcal vaccines. Copyright © 2013. Published by Mosby, Inc.

  15. Analysis of Haemophilus influenzae serotype f isolated from three Japanese children with invasive H. influenzae infection.

    PubMed

    Hoshino, Tadashi; Hachisu, Yushi; Kikuchi, Takashi; Tokutake, Shoko; Okui, Hideyuki; Kutsuna, Satoru; Fukasawa, Chie; Murayama, Kei; Oohara, Asami; Shimizu, Hiroyuki; Ito, Midori; Takahashi, Yoshiko; Ishiwada, Naruhiko

    2015-04-01

    In Japan, publicly subsidized Haemophilus influenzae serotype b vaccines became available in 2011; consequently, the incidence of invasive H. influenzae infection in paediatric patients of less than 5 years of age decreased dramatically. In 2013, the first case of H. influenzae serotype f (Hif) meningitis in a Japanese infant was reported, and another case of Hif meningitis in a Japanese infant was observed in 2013. We experienced a fatal paediatric case of Hif bacteraemia in 2004; therefore, we conducted an analysis of the three Hif strains isolated from these three Japanese children with invasive Hif infections. All three strains were β-lactamase-non-producing, ampicillin-sensitive strains, with MICs of 1 µg ml(-1) or less. However, one of the three strains showed slightly elevated MICs for ampicillin (1 µg ml(-1)), cefotaxime (0.25 µg ml(-1)) and meropenem (0.13 µg ml(-1)). A molecular analysis by multilocus sequence typing identified all three strains as sequence type (ST) 124, which is a predominant invasive Hif strain in many countries. SmaI-digested PFGE showed variable DNA fragmentation patterns among the strains, suggesting that some highly virulent strains have originated from a single ST124 clone and caused invasive Hif infections in Japan. Additional studies are needed to determine the factors that have led to the clonal expansion of virulent ST124 strains. © 2015 The Authors.

  16. Carbon storage regulator A contributes to the virulence of Haemophilus ducreyi in humans by multiple mechanisms.

    PubMed

    Gangaiah, Dharanesh; Li, Wei; Fortney, Kate R; Janowicz, Diane M; Ellinger, Sheila; Zwickl, Beth; Katz, Barry P; Spinola, Stanley M

    2013-02-01

    The carbon storage regulator A (CsrA) controls a wide variety of bacterial processes, including metabolism, adherence, stress responses, and virulence. Haemophilus ducreyi, the causative agent of chancroid, harbors a homolog of csrA. Here, we generated an unmarked, in-frame deletion mutant of csrA to assess its contribution to H. ducreyi pathogenesis. In human inoculation experiments, the csrA mutant was partially attenuated for pustule formation compared to its parent. Deletion of csrA resulted in decreased adherence of H. ducreyi to human foreskin fibroblasts (HFF); Flp1 and Flp2, the determinants of H. ducreyi adherence to HFF cells, were downregulated in the csrA mutant. Compared to its parent, the csrA mutant had a significantly reduced ability to tolerate oxidative stress and heat shock. The enhanced sensitivity of the mutant to oxidative stress was more pronounced in bacteria grown to stationary phase compared to that in bacteria grown to mid-log phase. The csrA mutant also had a significant survival defect within human macrophages when the bacteria were grown to stationary phase but not to mid-log phase. Complementation in trans partially or fully restored the mutant phenotypes. These data suggest that CsrA contributes to virulence by multiple mechanisms and that these contributions may be more profound in bacterial cell populations that are not rapidly dividing in the human host.

  17. In vitro chloramphenicol detection in a Haemophilus influenza model using an aptamer-polymer based electrochemical biosensor.

    PubMed

    Yadav, Saurabh K; Agrawal, Bharati; Chandra, Pranjal; Goyal, Rajendra N

    2014-05-15

    A sensitive and selective electrochemical biosensor is developed for the determination of chloramphenicol (CAP) exploring its direct electron transfer processes in in-vitro model and pharmaceutical samples. This biosensor exploits a selective binding of CAP with aptamer, immobilized onto the poly-(4-amino-3-hydroxynapthalene sulfonic acid) (p-AHNSA) modified edge plane pyrolytic graphite. The electrochemical reduction of CAP was observed in a well-defined peak. A quartz crystal microbalance (QCM) study is performed to confirm the interaction between the polymer film and the aptamer. Cyclic voltammetry (CV) and square wave voltammetry (SWV) were used to detect CAP. The in-vitro CAP detection is performed using the bacterial strain of Haemophilus influenza. A significant accumulation of CAP by the drug sensitive H. influenza strain is observed for the first time in this study using a biosensor. Various parameters affecting the CAP detection in standard solution and in in vitro detection are optimized. The detection of CAP is linear in the range of 0.1-2500 nM with the detection limit and sensitivity of 0.02 nM and 0.102 µA/nM, respectively. CAP is also detected in the presence of other common antibiotics and proteins present in the real sample matrix, and negligible interference is observed. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Cost-benefit analysis of a Haemophilus influenzae type b meningitis prevention programme in The Philippines.

    PubMed

    Limcangco, M R; Armour, C L; Salole, E G; Taylor, S J

    2001-01-01

    Haemophilus influenzae type b (Hib) meningitis is associated with high mortality and serious sequelae in children under 5 years of age. Vaccines which can prevent this infection are available. To evaluate the costs and benefits of a 3-dose immunisation schedule in Manila, Philippines. Government and societal perspectives. A cost-benefit analysis based on a birth cohort of 100,000 children. The state of health of the cohort with and without a Hib immunisation programme was modelled over a 5-year period. A survey of medical records of patients with Hib in Manila provided data on the extent and cost of sequelae following infection. A 3-dose Hib vaccination programme given at ages 2, 3 and 4 months. The model predicted that vaccinating children against Hib meningitis would prevent 553 cases per year in a birth cohort of 100,000, at a cost of 56,200 Philippine pesos (PHP) [$US1,605; 1998 exchange rate] per case (base case assumptions of 90% vaccine efficacy rate, 95 per 100,000 Hib incidence rate, 85% vaccination coverage). Results from the cost-benefit analyses indicated that the saving to the government would be around PHP39 million ($US1.11 million), and the saving to society would be PHP255 million ($US7.28 million). There would be a positive economic benefit for the Philippine government and for the Filipino society if a Hib vaccination programme was introduced in Manila.

  19. Longitudinal surveillance of Haemophilus influenzae isolates from pediatric patients with meningitis throughout Japan, 2000-2011.

    PubMed

    Ubukata, Kimiko; Chiba, Naoko; Morozumi, Miyuki; Iwata, Satoshi; Sunakawa, Keisuke

    2013-02-01

    In Japan, β-lactamase-nonproducing, ampicillin-resistant organisms have been evident among Haemophilus influenzae type b (Hib) isolates since 2000, when no appropriate vaccine had been approved. We therefore performed molecular analysis of agents causing H. influenzae meningitis nationwide over the following 10 years. Some 285 institutions have participated in surveillance since 2000. The capsular type and resistance genes of 1,353 isolates and 23 cerebrospinal fluid samples from pediatric patients with meningitis we had received from 2000 to 2011 were analyzed by polymerase chain reaction. Blood and spinal fluid test results obtained when patients were admitted were examined for correlation with outcomes. Hib was found in 98.9 % of isolates. We received more than 100 Hib isolates per year until vaccination began in December 2008, when these isolates decreased, especially since establishment of a special fund to promote vaccination in November 2010. Decreased incidence among infants 7 months to 2 years old has been particularly notable. However, the rate of ampicillin-resistant organisms has increased to more than 60 % of all isolates since 2009. We received 587 replies to a questionnaire concerning outcomes, indicating 2 % mortality and 17.7 % serious morbidity. Age of 6 months or younger and presence of disseminated intravascular coagulation at admission were related to an unfavorable outcome (p < 0.05), but ampicillin resistance was not. Combination therapy with third-generation cephem and carbapenem agents was used initially for 72 % of patients. Routine immunization can prevent Hib meningitis in children.

  20. Intranasal Immunization with Nontypeable Haemophilus influenzae Outer Membrane Vesicles Induces Cross-Protective Immunity in Mice

    PubMed Central

    Roier, Sandro; Leitner, Deborah R.; Iwashkiw, Jeremy; Schild-Prüfert, Kristina; Feldman, Mario F.; Krohne, Georg; Reidl, Joachim; Schild, Stefan

    2012-01-01

    Abstract Haemophilus influenzae is a Gram-negative human-restricted bacterium that can act as a commensal and a pathogen of the respiratory tract. Especially nontypeable H. influenzae (NTHi) is a major threat to public health and is responsible for several infectious diseases in humans, such as pneumonia, sinusitis, and otitis media. Additionally, NTHi strains are highly associated with exacerbations in patients suffering from chronic obstructive pulmonary disease. Currently, there is no licensed vaccine against NTHi commercially available. Thus, this study investigated the utilization of outer membrane vesicles (OMVs) as a potential vaccine candidate against NTHi infections. We analyzed the immunogenic and protective properties of OMVs derived from various NTHi strains by means of nasopharyngeal immunization and colonization studies with BALB/c mice. The results presented herein demonstrate that an intranasal immunization with NTHi OMVs results in a robust and complex humoral and mucosal immune response. Immunoprecipitation revealed the most important immunogenic proteins, such as the heme utilization protein, protective surface antigen D15, heme binding protein A, and the outer membrane proteins P1, P2, P5 and P6. The induced immune response conferred not only protection against colonization with a homologous NTHi strain, which served as an OMV donor for the immunization mixtures, but also against a heterologous NTHi strain, whose OMVs were not part of the immunization mixtures. These findings indicate that OMVs derived from NTHi strains have a high potential to act as a vaccine against NTHi infections. PMID:22880074

  1. Haemophilus influenzae type b disease in Auckland children during the Hib vaccination era: 1995-2009.

    PubMed

    Leung, Bonnie; Taylor, Susan; Drinkovic, Dragana; Roberts, Sally; Carter, Phil; Best, Emma

    2012-11-09

    To characterise Haemophilus influenzae type b (Hib) invasive disease in the era of Hib vaccination, in children of the greater Auckland region of New Zealand. Identification of sterile site culture positive Hib via the Auckland hospital laboratories databases and national laboratory surveillance database in the time period; 1995 to 2009. There were a total of 26 cases in the Auckland Region. Over the 15-year period, the annual incidence of invasive Hib disease was 0.61 per 100,000 (95% CI: 0.4-0.9) for children aged under 15 years and 1.65 per 100,000 (95% CI: 1.1-2.5) for children aged under 5 years. Ninety-two percent were under 5 years and 54% were under 1 year. Sixty percent of the children were of Maori and Pacific ethnicity. The predominant diagnosis was meningitis, accounting for 15 cases (60%). There were no fatalities. Forty-eight percent of affected children were completely unimmunised with the Hib vaccine which has been fully funded on the National Immunisation Schedule since 1994. Since the introduction of the Hib vaccine, the disease rates have greatly reduced in the Auckland region. Although ethnic disparities have improved amongst the cases that occur, immunisation rates in cases are low and infants remain most at risk. Current emphasis on intensifying immunisation programmes to achieve higher vaccination rates and timeliness of delivery will help in efforts to achieve elimination of the disease in New Zealand.

  2. Poor clinical outcome for meningitis caused by Haemophilus influenzae serotype A strains containing the IS1016-bexA deletion.

    PubMed

    Lima, Josilene B T; Ribeiro, Guilherme S; Cordeiro, Soraia M; Gouveia, Edilane L; Salgado, Kátia; Spratt, Brian G; Godoy, Daniel; Reis, Mitermayer G; Ko, Albert I; Reis, Joice N

    2010-11-15

    Since the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines, meningitis caused by serotypes other than Hib has gained in importance. We conducted active hospital-based surveillance for meningitis over an 11-year period in Salvador, Brazil. H. influenzae isolates were serotyped and analyzed by polymerase chain reaction, pulsed-field gel electrophoresis, and DNA sequencing to identify strains with a specific deletion (IS1016) in the bexA gene (IS1016-bexA). We identified 43 meningitis cases caused by non-type b H. influenzae: 28 (65%) were caused by type a (Hia), 9 (21%) were caused by noncapsulated strains, and 3 (7%) each were caused by types e and f. Hia isolates clustered in 2 clonal groups; clonal group A strains (n = 9) had the IS1016-bexA deletion. Among children <5 years of age, meningitis caused by Hia from clonal group A had higher case-fatality than meningitis caused by clonal group B. Despite small numbers, these results indicate that the presence of the IS1016-bexA deletion is associated with enhanced virulence in non-type b H. influenzae.

  3. Coinfection with Haemophilus influenzae promotes pneumococcal biofilm formation during experimental otitis media and impedes the progression of pneumococcal disease.

    PubMed

    Weimer, Kristin E D; Armbruster, Chelsie E; Juneau, Richard A; Hong, Wenzhou; Pang, Bing; Swords, W Edward

    2010-10-01

    Otitis media is an extremely common pediatric infection and is mostly caused by bacteria that are carried within the nasopharyngeal microbiota. It is clear that most otitis media cases involve simultaneous infection with multiple agents. Chinchillas were infected with nontypeable Haemophilus influenzae, Streptococcus pneumoniae, or a combination of both organisms, and the course of disease was compared. In vitro experiments were also performed to address how coinfection impacts biofilm formation. The incidence of systemic disease was reduced in coinfected animals, compared with those infected with pneumococcus alone. Pneumococci were present within surface-attached biofilms in coinfected animals, and a greater proportion of translucent colony type was observed in the coinfected animals. Because this colony type has been associated with pneumococcal biofilms, the impact of coinfection on pneumococcal biofilm formation was investigated. The results clearly show enhanced biofilm formation in vitro by pneumococci in the presence of H. influenzae. Based on these data, we conclude that coinfection with H. influenzae facilitates pneumococcal biofilm formation and persistence on the middle ear mucosal surface. This enhanced biofilm persistence correlates with delayed emergence of opaque colony variants within the bacterial population and a resulting decrease in systemic infection.

  4. Genomic Variability of Haemophilus influenzae Isolated from Mexican Children Determined by Using Enterobacterial Repetitive Intergenic Consensus Sequences and PCR

    PubMed Central

    Gomez-De-Leon, Patricia; Santos, Jose I.; Caballero, Javier; Gomez, Demostenes; Espinosa, Luz E.; Moreno, Isabel; Piñero, Daniel; Cravioto, Alejandro

    2000-01-01

    Genomic fingerprints from 92 capsulated and noncapsulated strains of Haemophilus influenzae from Mexican children with different diseases and healthy carriers were generated by PCR using the enterobacterial repetitive intergenic consensus (ERIC) sequences. A cluster analysis by the unweighted pair-group method with arithmetic averages based on the overall similarity as estimated from the characteristics of the genomic fingerprints, was conducted to group the strains. A total of 69 fingerprint patterns were detected in the H. influenzae strains. Isolates from patients with different diseases were represented by a variety of patterns, which clustered into two major groups. Of the 37 strains isolated from cases of meningitis, 24 shared patterns and were clustered into five groups within a similarity level of 1.0. One fragment of 1.25 kb was common to all meningitis strains. H. influenzae strains from healthy carriers presented fingerprint patterns different from those found in strains from sick children. Isolates from healthy individuals were more variable and were distributed differently from those from patients. The results show that ERIC-PCR provides a powerful tool for the determination of the distinctive pathogenicity potentials of H. influenzae strains and encourage its use for molecular epidemiology investigations. PMID:10878033

  5. Vaccination with Haemophilus influenzae type b conjugate vaccine reduces bacterial meningitis in Morocco.

    PubMed

    Braikat, Mohamed; Barkia, Abdelaziz; El Mdaghri, Naima; Rainey, Jeanette J; Cohen, Adam L; Teleb, Nadia

    2012-03-28

    Haemophilus influenzae type b (Hib) is a leading cause of bacterial meningitis and pneumonia and can be prevented by Hib vaccine. We conducted a vaccine impact evaluation to support continued use of Hib vaccine in Morocco following introduction in 2007. Bacterial meningitis surveillance data from 2004 to 2009 were obtained from 11 sentinel hospitals located in eight provinces and one prefecture in Morocco to examine Hi meningitis reporting for cases aged <5 years. We defined the years of 2004-2006 as the pre-vaccine period and 2008-2009 as the post-vaccine period and compared the mean annual number of confirmed Hi meningitis cases for these time periods using a Chi-square test. We calculated the minimum incidence of Hi meningitis during the evaluation period in Grand Casa Prefecture, where the catchment population could be estimated. From 2004 to 2009, 1844 suspected meningitis case-patients aged <5 years were reported; 354 (19.2%) were confirmed with bacterial meningitis, including 105 (29.7%) Hi cases. The mean annual number of confirmed Hi meningitis cases decreased by 75%, from 24 in the pre-vaccine period to 6 during the post-vaccine period (p<0.001). Assuming Hi cases with unknown age were <5 years of age, the estimated minimum incidence of confirmed Hi meningitis in Grand Casa Prefecture decreased by 93%, from 15 cases per 100,000 children in the pre-vaccine period to 1 case per 100,000 children in the post-vaccine period. Hib vaccine introduction likely significantly reduced the occurrence of Hi meningitis among children aged <5 years at the 11 sentinel hospitals included in this evaluation in Morocco, suggesting that continued use of Hib vaccine in Morocco would be beneficial. Published by Elsevier Ltd.

  6. Invasive Haemophilus influenzae disease in the vaccine era in Rio de Janeiro, Brazil

    PubMed Central

    Tuyama, Mari; Corrêa-Antônio, Jessica; Schlackman, Jessica; Marsh, Jane W; Rebelo, Maria C; Cerqueira, Elaine O; Nehab, Márcio; Kegele, Fabíola; Carmo, Getúlio F; Thielmann, Dominique CA; Barroso, Paulo F; Harrison, Lee H; Barroso, David E

    2017-01-01

    BACKGROUND Haemophilus influenzae (Hi) serotype b (Hib) conjugate vaccine was incorporated into the infant immunisation schedule in Brazil in 1999, where Hib was one of the major etiologic sources of community-acquired bacterial meningitis. OBJECTIVES The purpose of this study is to describe the molecular epidemiology of invasive Hi disease in Rio de Janeiro state, Brazil, before and after vaccine introduction. METHODS Surveillance data from 1986 to 2014 were analysed. Hi isolates recovered from cerebrospinal fluid (CSF) or blood from 1993 to 2014 were serotyped by slide agglutination, genotyped by multilocus sequence typing (MLST), and the capsule type evaluation, differentiation of serologically non-typeable isolates, and characterisation of the capsule (cap) locus was done by polymerase chain reaction. Antimicrobial susceptibility testing was performed using E-test. FINDINGS From 1986 to 1999 and from 2000 to 2014, 2580 and 197 (42% without serotype information) confirmed cases were reported, respectively. The case fatality rate was 17% and did not correlate with the strain. Hib and b- variant isolates belonged to ST-6, whereas serotype a isolates belonged to the ST-23 clonal complex. Serotype a appeared to emerge during the 2000s. Non-encapsulated isolates were non-clonal and distinct from the encapsulated isolates. Ampicillin-resistant isolates were either of serotype b or were non-encapsulated, and all of them were β-lactamase-positive but amoxicillin-clavulanic acid susceptible. MAIN CONCLUSIONS Although Hi meningitis became a relatively rare disease in Rio de Janeiro after the introduction of the Hib conjugate vaccine, the isolates recovered from patients have become more diverse. These results indicate the need to implement an enhanced surveillance system to continue monitoring the impact of the Hib conjugate vaccine. PMID:28225904

  7. The pharmacokinetic-pharmacodynamic modeling and cut-off values of tildipirosin against Haemophilus parasuis

    PubMed Central

    Lei, Zhixin; Liu, Qianying; Yang, Bing; Ahmed, Saeed; Cao, Jiyue; He, Qigai

    2018-01-01

    The goal of this study was to establish the epidemiological, pharmacodynamic cut-off values, optimal dose regimens for tildipirosin against Haemophilus parasuis. The minimum inhibitory concentrations (MIC) of 164 HPS isolates were determined and SH0165 whose MIC (2 μg/ml ) were selected for PD analysis. The ex vivo MIC in plasma of SH0165 was 0.25 μg/ml which was 8 times lower than that in TSB. The bacteriostatic, bactericidal and elimination activity (AUC24h/MIC) in serum were 26.35, 52.27 and 73.29 h based on the inhibitory sigmoid Emax modeling. The present study demonstrates that 97.9% of the wild-type (WT) isolates were covered when the epidemiological cut-off value (ECV) was set at 8 μg/ml. The parameters including AUC24h, AUC, T1/2, Cmax, CLb and MRT in PELF were 19.56, 60.41, 2.32, 4.02, 56.6, and 2.63 times than those in plasma, respectively. Regarding the Monte Carlo simulation, the COPD was defined as 0.5 μg/ml in vitro, and the optimal doses to achieve bacteriostatic, bactericidal and elimination effect were 1.85, 3.67 and 5.16 mg/kg for 50% target, respectively, and 2.07, 4.17 and 5.78 mg/kg for 90% target, respectively. The results of this study offer a more optimised alternative for clinical use and demonstrated that 4.17 mg/kg of tildipirosin by intramuscular injection could have an effect on bactericidal activity against HPS. These values are of great significance for the effective treatment of HPS infections, but it also be deserved to be validated in clinical practice in the future research. PMID:29416722

  8. Haemophilus ducreyi cutaneous ulcer contracted at Seram Island, Indonesia, presented in the Netherlands.

    PubMed

    van Hattem, Jarne M; Langeveld, Tessa J C; Bruisten, Sylvia M; Kolader, Marion; Grobusch, Martin P; de Vries, Henry J C; de Bree, Godelieve J

    2018-04-01

    We describe the first case of a cutaneous ulcer caused by Haemophilus ducreyi imported from Indonesia to the Netherlands. Skin infections caused by H. ducreyi are uncommon in travellers and have been described in just a few case reports and were all contracted on the Pacific Islands. A 22-year-old healthy male visited the Center of Tropical Medicine and Travel Medicine in February 2017 with a cutaneous ulcer of the right lateral malleolus 4 weeks after returning from Indonesia (Seram and Ambon Islands). He had noticed a small skin abrasion on the right ankle after slipping on a rock during a jungle trip on Seram Island. Back in the Netherlands, a painful ulcer developed at the same body location, and despite treatment with flucloxacillin, his complaints worsened. A swab that was taken for culture showed growth of small grey colonies that were characterised as H. ducreyi with matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry. Treatment with ciprofloxacin for the diagnosis of H. ducreyi cutaneous ulcer was started, and the ulcer clearly diminished, leaving only a small healing ulcer. H. ducreyi is normally the causative agent of genital ulcers but is increasingly recognised as a cause of chronic skin ulcers, e.g., in Papua New Guinea. In our patient, the infection was very likely contracted in the Maluku province of Indonesia and imported into the Netherlands. No reports of infection with H. ducreyi from Indonesia could be found in literature, but this case indicates that H. ducreyi is present in at least one of the northeastern islands of Indonesia, which is important for local healthcare. Additionally, it illustrates the role of this agent as a cause of cutaneous ulcers in previously healthy travellers.

  9. Fine tangled pili expressed by Haemophilus ducreyi are a novel class of pili.

    PubMed Central

    Brentjens, R J; Ketterer, M; Apicella, M A; Spinola, S M

    1996-01-01

    Haemophilus ducreyi synthesizes fine, tangled pili composed predominantly of a protein whose apparent molecular weight is 24,000 (24K). A hybridoma, 2D8, produced a monoclonal antibody (MAb) that bound to a 24K protein in H. ducreyi strains isolated from diverse geographic locations. A lambda gt11 H. ducreyi library was screened with MAb 2D8. A 3.5-kb chromosomal insert from one reactive plaque was amplified and ligated into the pCRII vector. The recombinant plasmid, designated pHD24, expressed a 24K protein in Escherichia coli INV alpha F that bound MAb 2D8. The coding sequence of the 24K gene was localized by exonuclease III digestion. The insert contained a 570-bp open reading frame, designated ftpA (fine, tangled pili). Translation of ftpA predicted a polypeptide with a molecular weight of 21.1K. The predicted N-terminal amino acid sequence of the polypeptide encoded by ftpA was identical to the N-terminal amino acid sequence of purified pilin and lacked a cleavable signal sequence. Primer extension analysis of ftpA confirmed the lack of a leader peptide. The predicted amino acid sequence lacked homology to known pilin sequences but shared homology with the sequences of E. coli Dps and Treponema pallidum antigen TpF1 or 4D, proteins which associate to form ordered rings. An isogenic pilin mutant, H. ducreyi 35000ftpA::mTn3(Cm), was constructed by shuttle mutagenesis and did not contain pili when examined by electron microscopy. We conclude that H. ducreyi synthesizes fine, tangled pili that are composed of a unique major subunit, which may be exported by a signal sequence independent mechanism. PMID:8550517

  10. Characterization of lactate utilization and its implication on the physiology of Haemophilus influenzae.

    PubMed

    Lichtenegger, Sabine; Bina, Isabelle; Roier, Sandro; Bauernfeind, Stilla; Keidel, Kristina; Schild, Stefan; Anthony, Mark; Reidl, Joachim

    2014-05-01

    Haemophilus influenzae is a Gram-negative bacillus and a frequent commensal of the human nasopharynx. Earlier work demonstrated that in H. influenzae type b, l-lactate metabolism is associated with serum resistance and in vivo survival of the organism. To further gain insight into lactate utilization of the non-typeable (NTHi) isolate 2019 and laboratory prototype strain Rd KW20, deletion mutants of the l-lactate dehydrogenase (lctD) and permease (lctP) were generated and characterized. It is shown, that the apparent KM of l-lactate uptake is 20.1μM as determined for strain Rd KW20. Comparison of the COPD isolate NTHi 2019-R with the corresponding lctP knockout strain for survival in human serum revealed no lactate dependent serum resistance. In contrast, we observed a 4-fold attenuation of the mutant strain in a murine model of nasopharyngeal colonization. Characterization of lctP transcriptional control shows that the lactate utilization system in H. influenzae is not an inductor inducible system. Rather negative feedback regulation was observed in the presence of l-lactate and this is dependent on the ArcAB regulatory system. Additionally, for 2019 it was found that lactate may have signaling function leading to increased cell growth in late log phase under conditions where no l-lactate is metabolized. This effect seems to be ArcA independent and was not observed in strain Rd KW20. We conclude that l-lactate is an important carbon-source and may act as host specific signal substrate which fine tunes the globally acting ArcAB regulon and may additionally affect a yet unknown signaling system and thus may contribute to enhanced in vivo survival. Copyright © 2014 Elsevier GmbH. All rights reserved.

  11. Structure of a small-molecule inhibitor complexed with GlmU from Haemophilus influenzae reveals an allosteric binding site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mochalkin, Igor; Lightle, Sandra; Narasimhan, Lakshmi

    2008-04-02

    N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) is an essential enzyme in aminosugars metabolism and an attractive target for antibiotic drug discovery. GlmU catalyzes the formation of uridine-diphospho-N-acetylglucosamine (UDP-GlcNAc), an important precursor in the peptidoglycan and lipopolisaccharide biosynthesis in both Gram-negative and Gram-positive bacteria. Here we disclose a 1.9 {angstrom} resolution crystal structure of a synthetic small-molecule inhibitor of GlmU from Haemophilus influenzae (hiGlmU). The compound was identified through a high-throughput screening (HTS) configured to detect inhibitors that target the uridyltransferase active site of hiGlmU. The original HTS hit exhibited a modest micromolar potency (IC{sub 50} - 18 {mu}M in a racemic mixture) againstmore » hiGlmU and no activity against Staphylococcus aureus GlmU (saGlmU). The determined crystal structure indicated that the inhibitor occupies an allosteric site adjacent to the GlcNAc-1-P substrate-binding region. Analysis of the mechanistic model of the uridyltransferase reaction suggests that the binding of this allosteric inhibitor prevents structural rearrangements that are required for the enzymatic reaction, thus providing a basis for structure-guided design of a new class of mechanism-based inhibitors of GlmU.« less

  12. Nonencapsulated Streptococcus pneumoniae causes otitis media during single-species infection and during polymicrobial infection with nontypeable Haemophilus influenzae.

    PubMed

    Murrah, Kyle A; Pang, Bing; Richardson, Stephen; Perez, Antonia; Reimche, Jennifer; King, Lauren; Wren, John; Swords, W Edward

    2015-07-01

    Streptococcus pneumoniae strains lacking capsular polysaccharide have been increasingly reported in carriage and disease contexts. Since most cases of otitis media involve more than one bacterial species, we aimed to determine the capacity of a nonencapsulated S. pneumoniae clinical isolate to induce disease in the context of a single-species infection and as a polymicrobial infection with nontypeable Haemophilus influenzae. Using the chinchilla model of otitis media, we found that nonencapsulated S. pneumoniae colonizes the nasopharynx following intranasal inoculation, but does not readily ascend into the middle ear. However, when we inoculated nonencapsulated S. pneumoniae directly into the middle ear, the bacteria persisted for two weeks post-inoculation and induced symptoms consistent with chronic otitis media. During coinfection with nontypeable H. influenzae, both species persisted for one week and induced polymicrobial otitis media. We also observed that nontypeable H. influenzae conferred passive protection from killing by amoxicillin upon S. pneumoniae from within polymicrobial biofilms in vitro. Therefore, based on these results, we conclude that nonencapsulated pneumococci are a potential causative agent of chronic/recurrent otitis media, and can also cause mutualistic infection with other opportunists, which could complicate treatment outcomes. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Impact of protein D-containing pneumococcal conjugate vaccines on non-typeable Haemophilus influenzae acute otitis media and carriage.

    PubMed

    Clarke, Christopher; Bakaletz, Lauren O; Ruiz-Guiñazú, Javier; Borys, Dorota; Mrkvan, Tomas

    2017-07-01

    Protein D-containing vaccines may decrease acute otitis media (AOM) burden and nasopharyngeal carriage of non-typeable Haemophilus influenzae (NTHi). Protein D-containing pneumococcal conjugate vaccine PHiD-CV (Synflorix, GSK Vaccines) elicits robust immune responses against protein D. However, the phase III Clinical Otitis Media and PneumoniA Study (COMPAS), assessing PHiD-CV efficacy against various pneumococcal diseases, was not powered to demonstrate efficacy against NTHi; only trends of protective efficacy against NTHi AOM in children were shown. Areas covered: This review aims to consider all evidence available to date from pre-clinical and clinical phase III studies together with further evidence emerging from post-marketing studies since PHiD-CV has been introduced into routine clinical practice worldwide, to better describe the clinical utility of protein D in preventing AOM due to NTHi and its impact on NTHi nasopharyngeal carriage. Expert commentary: Protein D is an effective carrier protein in conjugate vaccines and evidence gathered from pre-clinical, clinical and observational studies suggest that it also elicits immune response that can help to reduce the burden of AOM due to NTHi. There remains a need to develop improved vaccines for prevention of NTHi disease, which could be achieved by combining protein D with other antigens.

  14. Seventeen Sxy-Dependent Cyclic AMP Receptor Protein Site-Regulated Genes Are Needed for Natural Transformation in Haemophilus influenzae

    PubMed Central

    Mell, Joshua C.; Redfield, Rosemary J.

    2012-01-01

    Natural competence is the ability of bacteria to actively take up extracellular DNA. This DNA can recombine with the host chromosome, transforming the host cell and altering its genotype. In Haemophilus influenzae, natural competence is induced by energy starvation and the depletion of nucleotide pools. This induces a 26-gene competence regulon (Sxy-dependent cyclic AMP receptor protein [CRP-S] regulon) whose expression is controlled by two regulators, CRP and Sxy. The role of most of the CRP-S genes in DNA uptake and transformation is not known. We have therefore created in-frame deletions of each CRP-S gene and studied their competence phenotypes. All but one gene (ssb) could be deleted. Although none of the remaining CRP-S genes were required for growth in rich medium or survival under starvation conditions, DNA uptake and transformation were abolished or reduced in most of the mutants. Seventeen genes were absolutely required for transformation, with 14 of these genes being specifically required for the assembly and function of the type IV pilus DNA uptake machinery. Only five genes were dispensable for both competence and transformation. This is the first competence regulon for which all genes have been mutationally characterized. PMID:22821979

  15. Porcine coronin 1A contributes to nuclear factor-kappa B (NF-κB) inactivation during Haemophilus parasuis infection.

    PubMed

    Liu, Chong; Wang, Yang; Zhang, Hengling; Cheng, Shuang; Charreyre, Catherine; Audonnet, Jean Christophe; Chen, Pin; He, Qigai

    2014-01-01

    Haemophilus parasuis (H.parasuis) is the etiological agent of porcine polyserositis and arthritis (Glässer's disease) characterized by fibrinous polyserositis, meningitis and polyarthritis, causing severe economic losses to the swine industry. Currently, the molecular basis of this infection is largely unkonwn. Coronin 1A (Coro1A) plays important roles in host against bacterial infection, yet little is known about porcine Coro1A. In this study, we investigated the molecular characterization of porcine Coro1A, revealing that porcine Coro1A was widely expressed in different tissues. Coro1A could be induced by lipopolysaccharide (LPS), polyinosinic acid-polycytidylic acid [poly (I:C)] and H.parasuis in porcine kidney-15 (PK-15) cells. Functional analyses revealed that porcine Coro1A suppressed the NF-κB activation during H.parasuis infection by inhibiting the degradation of IκBα and nuclear translocation of p65. Overexpression of porcine Coro1A inhibited the transcription of NF-κB-mediated downstream genes [Interleukin-6 (IL-6), Interleukin-8 (IL-8) and COX-2] through down-regulation of NF-κB. The results indicated that porcine Coro1A is an important immunity related gene that helps to inhibit NF-kB activation during H. parasuis infection.

  16. Efficacy of humanlike Augmentin SR (2000/125 mg) twice daily treatment on Haemophilus influenzae experimental pneumonia in rabbits.

    PubMed

    Croisier, Delphine; Benoit, Martha; Durand, David; Lequeu, Catherine; Piroth, Lionel; Portier, Henri; Chavanet, Pascal

    2007-01-01

    We investigated the efficacy of 2 formulations of Augmentin on experimental pneumonia due to Haemophilus influenzae (HI) in rabbits. Two strains were used (H128 and 401285) with amoxicillin/clavulanic acid MICs of 1/0.5 mg/l and 4/2 mg/l. Pneumonia was induced in immunocompetent rabbits by inoculation of 10 log(10) CFU HI. The treatments were infused by using computer controlled pumps in order to mimic the human pharmacokinetic (PK) profile of either conventional Augmentin treatment (875/125 mg twice daily) or the sustained release formulation (SR: 2000/125 mg twice daily). After 2 d of treatment, the bacterial concentrations in the lungs were similar for both strains and both treatments: isolate H128, conventional Augmentin reduced bacterial numbers to 3.8+/-2.1 log(10) CFU/g and Augmentin SR to 3.1+/-2.4 log(10) CFU/g; isolate 401285, conventional Augmentin to 3.5+/-2. Thus, both treatments demonstrated similar efficacy against H. influenzae pneumonia in this model, even when induced by a strain with an amoxicillin/clavulanic acid MIC of 4/2 mg/l. These results support current breakpoints for conventional Augmentin against H. influenzae and suggest that Augmentin SR is at least as effective against these isolates.

  17. The Role of Regulatory T Cell in Nontypeable Haemophilus influenzae-Induced Acute Exacerbation of Chronic Obstructive Pulmonary Disease

    PubMed Central

    Guan, Xuewa; Lu, Yanjiao; Wang, Guoqiang; Fang, Keyong; Wang, Ziyan; Pang, Zhiqiang; Guo, Yingqiao; Lu, Junying; Yuan, Yuze; Ran, Nan

    2018-01-01

    Chronic obstructive pulmonary disease (COPD) is associated with irreversible persistent airflow limitation and enhanced inflammation. The episodes of acute exacerbation (AECOPD) largely depend on the colonized pathogens such as nontypeable Haemophilus influenzae (NTHi), one of the most commonly isolated bacteria. Regulatory T cells (Tregs) are critical in controlling inflammatory immune responses and maintaining tolerance; however, their role in AECOPD is poorly understood. In this study, we hypothesized a regulatory role of Tregs, as NTHi participated in the progress of COPD. Immunological pathogenesis was investigated in a murine COPD model induced by cigarette smoke (CS). NTHi was administrated through intratracheal instillation for an acute exacerbation. Weight loss and lung function decline were observed in smoke-exposed mice. Mice in experimental groups exhibited serious inflammatory responses via histological and cytokine assessment. Expression levels of Tregs and Th17 cells with specific cytokines TGF-β1 and IL-17 were detected to assess the balance of pro-/anti-inflammatory influence partially. Our findings suggested an anti-inflammatory activity of Tregs in CS-induced model. But this activity was suppressed after NTHi administration. Collectively, these data suggested that NTHi might play a necessary role in downregulating Foxp3 to impair the function of Tregs, helping development into AECOPD. PMID:29725272

  18. [A case of pulmonary abscess in which Haemophilus parainfluenzae and Streptococcus intermedius were isolated by percutaneous needle aspiration].

    PubMed

    Miyamoto, Atsushi; Tsuboi, Eiyasu; Takaya, Hisashi; Sugino, Keishi; Sakamoto, Susumu; Kawabata, Masateru; Kishi, Kazuma; Narui, Koji; Homma, Sakae; Nakatani, Tatsuo; Nakata, Koichiro; Yoshimura, Kunihiko

    2006-08-01

    Some microbes, including the Bacteroides species, Staphylococcus aureus and Streptococcus milleri groups, can cause pulmonary abscess. Haemophilus parainfluenzae is usually categorized as one of the normal flora which colonizes in the ears and the nasopharynx, and it has been long considered that H. parainfluenzae has little pathogenicity in the lower respiratory tract and lung parenchymal. In this report, we present a case of pulmonary abscess caused by both H. parainfluenzae and Streptococcus intermedius. The patient was a 75-year-old man who had had total esophageo-gastrectomy because of esophageal cancer. He presented with purulent sputum, and chest X-ray film showed a dense consolidation in the right upper lung field. CT-guided transcutaneous fine needle aspiration was performed as a diagnostic procedure. Since both H. parainfluenzae and S. intermedius had been isolated from the lesion, pulmonary abscess caused by these two pathogens was diagnosed. The patient was treated with panipenem/betamipron, and his symptoms and pulmonary infiltrates on the chest X-ray film improved thereafter. So far, very few cases have been reported in which H. parainfluenzae caused lower respiratory tract infection. Although S. intermedius is known as one of the pathogens of pulmonary abscess, it is possible that H. parainfluenzae could also be pathogenic in infectious diseases of the lung.

  19. Nonencapsulated or nontypeable Haemophilus influenzae are more likely than their encapsulated or serotypeable counterparts to have mutations in their fucose operon.

    PubMed

    Shuel, Michelle L; Karlowsky, Kathleen E; Law, Dennis K S; Tsang, Raymond S W

    2011-12-01

    Population biology of Haemophilus influenzae can be studied by multilocus sequence typing (MLST), and isolates are assigned sequence types (STs) based on nucleotide sequence variations in seven housekeeping genes, including fucK. However, the ST cannot be assigned if one of the housekeeping genes is absent or cannot be detected by the current protocol. Occasionally, strains of H. influenzae have been reported to lack the fucK gene. In this study, we examined the prevalence of this mutation among our collection of H. influenzae isolates. Of the 704 isolates studied, including 282 encapsulated and 422 nonencapsulated isolates, nine were not typeable by MLST owing to failure to detect the fucK gene. All nine fucK-negative isolates were nonencapsulated and belonged to various biotypes. DNA sequencing of the fucose operon region confirmed complete deletion of genes in the operon in seven of the nine isolates, while in the remaining two isolates, some of the genes were found intact or in parts. The significance of these findings is discussed.

  20. Experimental infection with Haemophilus ducreyi in persons who are infected with HIV does not cause local or augment systemic viral replication.

    PubMed

    Janowicz, Diane M; Tenner-Racz, Klara; Racz, Paul; Humphreys, Tricia L; Schnizlein-Bick, Carol; Fortney, Kate R; Zwickl, Beth; Katz, Barry P; Campbell, James J; Ho, David D; Spinola, Stanley M

    2007-05-15

    We infected 11 HIV-seropositive volunteers whose CD4(+) cell counts were >350 cells/ microL (7 of whom were receiving antiretrovirals) with Haemophilus ducreyi. The papule and pustule formation rates were similar to those observed in HIV-seronegative historical control subjects. No subject experienced a sustained change in CD4(+) cell count or HIV RNA level. The cellular infiltrate in biopsy samples obtained from the HIV-seropositive and HIV-seronegative subjects did not differ with respect to the percentage of leukocytes, neutrophils, macrophages, or T cells. The CD4(+):CD8(+) cell ratio in biopsy samples from the HIV-seropositive subjects was 1:3, the inverse of the ratio seen in the HIV-seronegative subjects (P<.0001). Although CD4(+) cells proliferated in lesions, in situ hybridization and reverse-transcription polymerase chain reaction for HIV RNA was negative. We conclude that experimental infection in HIV-seropositive persons is clinically similar to infection in HIV-seronegative persons and does not cause local or augment systemic viral replication. Thus, prompt treatment of chancroid may abrogate increases in viral replication associated with natural disease.

  1. Accelerating policy decisions to adopt haemophilus influenzae type B vaccine: a global, multivariable analysis.

    PubMed

    Shearer, Jessica C; Stack, Meghan L; Richmond, Marcie R; Bear, Allyson P; Hajjeh, Rana A; Bishai, David M

    2010-03-16

    Adoption of new and underutilized vaccines by national immunization programs is an essential step towards reducing child mortality. Policy decisions to adopt new vaccines in high mortality countries often lag behind decisions in high-income countries. Using the case of Haemophilus influenzae type b (Hib) vaccine, this paper endeavors to explain these delays through the analysis of country-level economic, epidemiological, programmatic and policy-related factors, as well as the role of the Global Alliance for Vaccines and Immunisation (GAVI Alliance). Data for 147 countries from 1990 to 2007 were analyzed in accelerated failure time models to identify factors that are associated with the time to decision to adopt Hib vaccine. In multivariable models that control for Gross National Income, region, and burden of Hib disease, the receipt of GAVI support speeded the time to decision by a factor of 0.37 (95% CI 0.18-0.76), or 63%. The presence of two or more neighboring country adopters accelerated decisions to adopt by a factor of 0.50 (95% CI 0.33-0.75). For each 1% increase in vaccine price, decisions to adopt are delayed by a factor of 1.02 (95% CI 1.00-1.04). Global recommendations and local studies were not associated with time to decision. This study substantiates previous findings related to vaccine price and presents new evidence to suggest that GAVI eligibility is associated with accelerated decisions to adopt Hib vaccine. The influence of neighboring country decisions was also highly significant, suggesting that approaches to support the adoption of new vaccines should consider supply- and demand-side factors.

  2. Trimeric autotransporter DsrA is a major mediator of fibrinogen binding in Haemophilus ducreyi.

    PubMed

    Fusco, William G; Elkins, Christopher; Leduc, Isabelle

    2013-12-01

    Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. In both natural and experimental chancroid, H. ducreyi colocalizes with fibrin at the base of the ulcer. Fibrin is obtained by cleavage of the serum glycoprotein fibrinogen (Fg) by thrombin to initiate formation of the blood clot. Fg binding proteins are critical virulence factors in medically important Gram-positive bacteria. H. ducreyi has previously been shown to bind Fg in an agglutination assay, and the H. ducreyi Fg binding protein FgbA was identified in ligand blotting with denatured proteins. To better characterize the interaction of H. ducreyi with Fg, we examined Fg binding to intact, viable H. ducreyi bacteria and identified a novel Fg binding protein. H. ducreyi bound unlabeled Fg in a dose-dependent manner, as measured by two different methods. In ligand blotting with total denatured cellular proteins, digoxigenin (DIG)-Fg bound only two H. ducreyi proteins, the trimeric autotransporter DsrA and the lectin DltA; however, only the isogenic dsrA mutant had significantly less cell-associated Fg than parental strains in Fg binding assays with intact bacteria. Furthermore, expression of DsrA, but not DltA or an empty vector, rendered the non-Fg-binding H. influenzae strain Rd capable of binding Fg. A 13-amino-acid sequence in the C-terminal section of the passenger domain of DsrA appears to be involved in Fg binding by H. ducreyi. Taken together, these data suggest that the trimeric autotransporter DsrA is a major determinant of Fg binding at the surface of H. ducreyi.

  3. Trimeric Autotransporter DsrA Is a Major Mediator of Fibrinogen Binding in Haemophilus ducreyi

    PubMed Central

    Fusco, William G.; Elkins, Christopher

    2013-01-01

    Haemophilus ducreyi is the etiologic agent of the sexually transmitted genital ulcer disease chancroid. In both natural and experimental chancroid, H. ducreyi colocalizes with fibrin at the base of the ulcer. Fibrin is obtained by cleavage of the serum glycoprotein fibrinogen (Fg) by thrombin to initiate formation of the blood clot. Fg binding proteins are critical virulence factors in medically important Gram-positive bacteria. H. ducreyi has previously been shown to bind Fg in an agglutination assay, and the H. ducreyi Fg binding protein FgbA was identified in ligand blotting with denatured proteins. To better characterize the interaction of H. ducreyi with Fg, we examined Fg binding to intact, viable H. ducreyi bacteria and identified a novel Fg binding protein. H. ducreyi bound unlabeled Fg in a dose-dependent manner, as measured by two different methods. In ligand blotting with total denatured cellular proteins, digoxigenin (DIG)-Fg bound only two H. ducreyi proteins, the trimeric autotransporter DsrA and the lectin DltA; however, only the isogenic dsrA mutant had significantly less cell-associated Fg than parental strains in Fg binding assays with intact bacteria. Furthermore, expression of DsrA, but not DltA or an empty vector, rendered the non-Fg-binding H. influenzae strain Rd capable of binding Fg. A 13-amino-acid sequence in the C-terminal section of the passenger domain of DsrA appears to be involved in Fg binding by H. ducreyi. Taken together, these data suggest that the trimeric autotransporter DsrA is a major determinant of Fg binding at the surface of H. ducreyi. PMID:24042118

  4. Protective effect of breastfeeding: an ecologic study of Haemophilus influenzae meningitis and breastfeeding in a Swedish population.

    PubMed

    Silfverdal, S A; Bodin, L; Olcén, P

    1999-02-01

    In Orebro County, Sweden, a 2.5-fold increase in the incidence of Haemophilus influenzae (HI) meningitis was found between 1970 and 1980. In a case-control study of possible risk factors for invasive HI infection conducted in the same area, 1987-1992, breastfeeding was found to be a strong protective factor. In order to study the relation between incidence rates of HI meningitis between 1956-1992 and breastfeeding rates in the population an ecologic study was performed. A strong (negative) correlation between breastfeeding and incidence of HI infection 5 to 10 years later (rho(xy) (s) approximately -0.6) was seen, whereas no relation seems to exist for the time lag 15 years and beyond. The correlation for contemporary data was intermediate. There were similar results for the breastfeeding proportions at 2, 4 as well as 6 months of age. Our ecologic data are consistent with results from our case-control study. The time-lag for the delayed effect on the population level could be estimated although sparse data make the estimates vulnerable to sampling fluctuations. Limitations with ecologic studies are discussed. There seems to be an association between high breastfeeding rate in the population and a reduced incidence of HI meningitis 5 to 10 years later. These results do have implications on strategies for breastfeeding promotion, especially in countries where Hib vaccination is too costly and not yet implemented.

  5. Haemophilus influenzae genome evolution during persistence in the human airways in chronic obstructive pulmonary disease.

    PubMed

    Pettigrew, Melinda M; Ahearn, Christian P; Gent, Janneane F; Kong, Yong; Gallo, Mary C; Munro, James B; D'Mello, Adonis; Sethi, Sanjay; Tettelin, Hervé; Murphy, Timothy F

    2018-04-03

    Nontypeable Haemophilus influenzae (NTHi) exclusively colonize and infect humans and are critical to the pathogenesis of chronic obstructive pulmonary disease (COPD). In vitro and animal models do not accurately capture the complex environments encountered by NTHi during human infection. We conducted whole-genome sequencing of 269 longitudinally collected cleared and persistent NTHi from a 15-y prospective study of adults with COPD. Genome sequences were used to elucidate the phylogeny of NTHi isolates, identify genomic changes that occur with persistence in the human airways, and evaluate the effect of selective pressure on 12 candidate vaccine antigens. Strains persisted in individuals with COPD for as long as 1,422 d. Slipped-strand mispairing, mediated by changes in simple sequence repeats in multiple genes during persistence, regulates expression of critical virulence functions, including adherence, nutrient uptake, and modification of surface molecules, and is a major mechanism for survival in the hostile environment of the human airways. A subset of strains underwent a large 400-kb inversion during persistence. NTHi does not undergo significant gene gain or loss during persistence, in contrast to other persistent respiratory tract pathogens. Amino acid sequence changes occurred in 8 of 12 candidate vaccine antigens during persistence, an observation with important implications for vaccine development. These results indicate that NTHi alters its genome during persistence by regulation of critical virulence functions primarily by slipped-strand mispairing, advancing our understanding of how a bacterial pathogen that plays a critical role in COPD adapts to survival in the human respiratory tract.

  6. Long-term mortality in children diagnosed with Haemophilus influenzae meningitis: a Danish nationwide cohort study.

    PubMed

    Roed, Casper; Engsig, Frederik Neess; Omland, Lars Haukali; Skinhoj, Peter; Obel, Niels

    2011-08-01

    The long-term mortality in children diagnosed with Haemophilus influenzae meningitis is poorly documented. We performed a nationwide, population-based cohort study including all Danish children diagnosed at the age between 0 and <5 years with H. influenzae meningitis from 1977 through 1996 and who were alive 1 year after diagnosis. Data were retrieved from medical databases in Denmark. For each H. influenzae meningitis patient, 6 age- and gender-matched population controls were indentified. We constructed Kaplan-Meier survival curves and used Cox regression analysis to estimate mortality rate ratios (MRR) and analyze causes of death. The risk of inpatient admission and of requiring hospital outpatient services during follow-up was calculated. We identified 1242 H. influenzae meningitis patients and 7452 population controls, with a median follow-up time of 21.3 years. The MRR for patients with H. influenzae meningitis was 1.08 (95% confidence interval, 0.57-2.05), adjusted MRR was 0.97 (95% confidence interval, 0.50-1.89). No increased mortality due to infections, respiratory diseases, or cancer was observed. The overall risk of inpatient admission and of requiring hospital outpatient services for the H. influenzae meningitis patients was increased the first 15 years of follow-up, mainly due to the nervous system diseases and ear diseases, thereafter the risk decreased to that of the population controls. In a developed country, children younger than 5 years surviving the acute phase of H. influenzae meningitis have no increased long-term mortality and only moderately increased morbidity.

  7. Haemophilus influenzae Type b Disease and Vaccine Booster Dose Deferral, United States, 1998–2009

    PubMed Central

    Briere, Elizabeth C.; Jackson, Michael; Shah, Shetul G.; Cohn, Amanda C.; Anderson, Raydel D.; MacNeil, Jessica R.; Coronado, Fatima M.; Mayer, Leonard W.; Clark, Thomas A.; Messonnier, Nancy E.

    2015-01-01

    BACKGROUND Since the introduction of effective vaccines, the incidence of invasive Haemophilus influenzae type b (Hib) disease among children <5 years of age has decreased by 99% in the United States. In response to a limited vaccine supply that began in 2007, Hib booster doses were deferred for 18 months. METHODS We reviewed national passive and active surveillance (demographic and serotype) and vaccination status data for invasive H. influenzae disease in children aged <5 years before (1998–2007) and during (2008–2009) the vaccine shortage years to assess the impact of the vaccine deferral on Hib disease. We estimated the average annual number of Hib cases misclassified as unknown (not completed or missing) serotype. RESULTS From 1998 to 2007 and 2008 to 2009, the annual average incidence of Hib disease per 100 000 population was 0.2 and 0.18, respectively; no significant difference in incidence was found by age group, gender, or race. Among Hib cases in both time periods, most were unvaccinated or too young to have received Hib vaccine. During 2001 to 2009, there were <53 Hib cases per year, with an estimated 6 to 12 Hib cases misclassified as unknown serotype. CONCLUSIONS The booster deferral did not have a significant impact on the burden of invasive Hib disease in children <5 years of age. Continued surveillance and serotype data are important to monitor changes in Hib incidence, especially during vaccine deferrals. Hib booster deferral is a reasonable short-term approach to a Hib vaccine shortage. PMID:22869828

  8. RbsB (NTHI_0632) mediates quorum signal uptake in nontypeable Haemophilus influenzae strain 86-028NP

    PubMed Central

    Armbruster, Chelsie E.; Pang, Bing; Murrah, Kyle; Juneau, Richard A.; Perez, Antonia C.; Weimer, Kristin E.D.; Swords, W. Edward

    2011-01-01

    Summary Nontypeable Haemophilus influenzae (NTHI) is a respiratory commensal and opportunistic pathogen, which persists within biofilms on airway mucosal surfaces. For many species, biofilm formation is impacted by quorum signaling. Our prior work shows that production of autoinducer-2 (AI-2) promotes biofilm development and persistence for NTHI 86-028NP. NTHI 86-028NP encodes an ABC transporter annotated as a ribose transport system that includes a protein (RbsB) with similarity to the Escherichia coli LsrB and Aggregatibacter actinomycetemcomitans RbsB proteins that bind AI-2. In this study, inactivation of rbsB significantly reduced uptake of AI-2 and the AI-2 precursor dihydroxypentanedione (DPD) by NTHI 86-028NP. Moreover, DPD uptake was not competitively inhibited by ribose or other pentose sugars. Transcript levels of rbsB increased in response to DPD and as bacteria approached stationary-phase growth. The NTHI 86-028NP rbsB mutant also formed biofilms with significantly reduced thickness and total biomass and reduced surface phosphorylcholine, similar to a luxS mutant. Infection studies revealed that loss of rbsB impaired bacterial persistence in the chinchilla middle-ear, similar to our previous results with luxS mutants. Based on these data, we conclude that in NTHI 86-028NP, RbsB is a LuxS/AI-2 regulated protein that is required for uptake of and response to AI-2. PMID:21923771

  9. RbsB (NTHI_0632) mediates quorum signal uptake in nontypeable Haemophilus influenzae strain 86-028NP.

    PubMed

    Armbruster, Chelsie E; Pang, Bing; Murrah, Kyle; Juneau, Richard A; Perez, Antonia C; Weimer, Kristin E D; Swords, W Edward

    2011-11-01

    Nontypeable Haemophilus influenzae (NTHI) is a respiratory commensal and opportunistic pathogen, which persists within biofilms on airway mucosal surfaces. For many species, biofilm formation is impacted by quorum signalling. Our prior work shows that production of autoinducer-2 (AI-2) promotes biofilm development and persistence for NTHI 86-028NP. NTHI 86-028NP encodes an ABC transporter annotated as a ribose transport system that includes a protein (RbsB) with similarity to the Escherichia coli LsrB and Aggregatibacter actinomycetemcomitans RbsB proteins that bind AI-2. In this study, inactivation of rbsB significantly reduced uptake of AI-2 and the AI-2 precursor dihydroxypentanedione (DPD) by NTHI 86-028NP. Moreover, DPD uptake was not competitively inhibited by ribose or other pentose sugars. Transcript levels of rbsB increased in response to DPD and as bacteria approached stationary-phase growth. The NTHI 86-028NP rbsB mutant also formed biofilms with significantly reduced thickness and total biomass and reduced surface phosphorylcholine, similar to a luxS mutant. Infection studies revealed that loss of rbsB impaired bacterial persistence in the chinchilla middle ear, similar to our previous results with luxS mutants. Based on these data, we conclude that in NTHI 86-028NP, RbsB is a LuxS/AI-2 regulated protein that is required for uptake of and response to AI-2. © 2011 Blackwell Publishing Ltd.

  10. Position-based scanning for comparative genomics and identification of genetic islands in Haemophilus influenzae type b.

    PubMed

    Bergman, Nicholas H; Akerley, Brian J

    2003-03-01

    Bacteria exhibit extensive genetic heterogeneity within species. In many cases, these differences account for virulence properties unique to specific strains. Several such loci have been discovered in the genome of the type b serotype of Haemophilus influenzae, a human pathogen able to cause meningitis, pneumonia, and septicemia. Here we report application of a PCR-based scanning procedure to compare the genome of a virulent type b (Hib) strain with that of the laboratory-passaged Rd KW20 strain for which a complete genome sequence is available. We have identified seven DNA segments or H. influenzae genetic islands (HiGIs) present in the type b genome and absent from the Rd genome. These segments vary in size and content and show signs of horizontal gene transfer in that their percent G+C content differs from that of the rest of the H. influenzae genome, they contain genes similar to those found on phages or other mobile elements, or they are flanked by DNA repeats. Several of these loci represent potential pathogenicity islands, because they contain genes likely to mediate interactions with the host. These newly identified genetic islands provide areas of investigation into both the evolution and pathogenesis of H. influenzae. In addition, the genome scanning approach developed to identify these islands provides a rapid means to compare the genomes of phenotypically diverse bacterial strains once the genome sequence of one representative strain has been determined.

  11. The Haemophilus ducreyi LspA1 protein inhibits phagocytosis by using a new mechanism involving activation of C-terminal Src kinase.

    PubMed

    Dodd, Dana A; Worth, Randall G; Rosen, Michael K; Grinstein, Sergio; van Oers, Nicolai S C; Hansen, Eric J

    2014-05-20

    Haemophilus ducreyi causes chancroid, a sexually transmitted infection. A primary means by which this pathogen causes disease involves eluding phagocytosis; however, the molecular basis for this escape mechanism has been poorly understood. Here, we report that the LspA virulence factors of H. ducreyi inhibit phagocytosis by stimulating the catalytic activity of C-terminal Src kinase (Csk), which itself inhibits Src family protein tyrosine kinases (SFKs) that promote phagocytosis. Inhibitory activity could be localized to a 37-kDa domain (designated YL2) of the 456-kDa LspA1 protein. The YL2 domain impaired ingestion of IgG-opsonized targets and decreased levels of active SFKs when expressed in mammalian cells. YL2 contains tyrosine residues in two EPIYG motifs that are phosphorylated in mammalian cells. These tyrosine residues were essential for YL2-based inhibition of phagocytosis. Csk was identified as the predominant mammalian protein interacting with YL2, and a dominant-negative Csk rescued phagocytosis in the presence of YL2. Purified Csk phosphorylated the tyrosines in the YL2 EPIYG motifs. Phosphorylated YL2 increased Csk catalytic activity, resulting in positive feedback, such that YL2 can be phosphorylated by the same kinase that it activates. Finally, we found that the Helicobacter pylori CagA protein also inhibited phagocytosis in a Csk-dependent manner, raising the possibility that this may be a general mechanism among diverse bacteria. Harnessing Csk to subvert the Fcγ receptor (FcγR)-mediated phagocytic pathway represents a new bacterial mechanism for circumventing a crucial component of the innate immune response and may potentially affect other SFK-involved cellular pathways. Phagocytosis is a critical component of the immune system that enables pathogens to be contained and cleared. A number of bacterial pathogens have developed specific strategies to either physically evade phagocytosis or block the intracellular signaling required for

  12. Bacteriophage of Haemophilus influenzae III. Morphology, DNA Homology, and Immunity Properties of HP1c1, S2, and the Defective Bacteriophage from Strain Rd

    PubMed Central

    Boling, Maxon E.; Allison, David P.; Setlow, Jane K.

    1973-01-01

    The phages HP1c1 and S2 and a defective phage of Haemophilus influenzae have been compared. The morphology of the phages and the mol wt of their DNAs are similar, although the defective phage appears to have a different tail plate region. Electron microscope observation indicates that the defective phage does not attach to the cell surface, and its DNA appears to lack cohesive ends. The homology of the DNAs of the phages has been measured by hydridization. DNA from the defective phage shows little or no homology with the other phage DNAs. HP1c1 and S2 DNAs show a high level of homology. Each of these phages can form plaques on lawns of the lysogen of the other phage but at reduced plating efficiencies, suggesting that the two phages have related but not identical immunity systems. Images PMID:4540713

  13. Impact of introduction of the Haemophilus influenzae type b conjugate vaccine into childhood immunization on meningitis in Bangladeshi infants.

    PubMed

    Sultana, Nadira K; Saha, Samir K; Al-Emran, Hassan M; Modak, Joyanta K; Sharker, M A Yushuf; El-Arifeen, Shams; Cohen, Adam L; Baqui, Abdullah H; Luby, Stephen P

    2013-07-01

    Some Asian countries have been reluctant to adopt Haemophilus influenzae type b (Hib) conjugate vaccination because of uncertainty over disease burden. We assessed the impact of introduction of Hib conjugate vaccine into the Expanded Program on Immunization in Bangladesh on purulent and laboratory-confirmed H influenzae meningitis. Within a well-defined catchment area around 2 surveillance hospitals in Dhaka, Bangladesh, we compared the incidence of Hib meningitis confirmed by culture, latex agglutination, and polymerase chain reaction assay among infants 1 year before and 1 year after introduction of Hib conjugate vaccine. We adjusted the incidence rate for the proportion of children who sought care at the surveillance hospitals. Among infants, the incidence of confirmed Hib meningitis decreased from 92-16 cases per 100,000 within 1 year of vaccine introduction (vaccine preventable incidence = 76; 95% CI 18, 135 per 100,000). The incidence of purulent meningitis decreased from 1659-1159 per 100,000 (vaccine preventable incidence = 500; 95% CI: 203, 799 per 100,000). During the same time period, there was no significant difference in the incidence of meningitis due to Streptococcus pneumoniae. Introduction of conjugate Hib conjugate vaccine into Bangladesh Expanded Program on Immunization markedly reduced the burden of Hib and purulent meningitis. Copyright © 2013. Published by Mosby, Inc.

  14. Coinfection with Haemophilus influenzae promotes pneumococcal biofilm formation during experimental otitis media and impedes the progression of pneumococcal disease

    PubMed Central

    Weimer, Kristin E.D.; Armbruster, Chelsie E.; Juneau, Richard A.; Hong, Wenzhou; Pang, Bing; Swords, W. Edward

    2010-01-01

    Background Otitis media is an extremely common pediatric infection, and is mostly caused by bacteria that are carried within the nasopharyngeal microbiota. It is clear that most otitis media cases involve simultaneous infection with multiple agents. Methods Chinchillas were infected with nontypeable Haemophilus influenzae, Streptococcus pneumoniae, or a combination of both organisms, and the course of disease was compared. In vitro experiments were also performed to address how coinfection impacts biofilm formation. Results The incidence of systemic disease was reduced in coinfected animals as compared to those infected with pneumococcus alone. Pneumococci were present within surface-attached biofilms in coinfected animals, and a greater proportion of translucent colony type was observed in the coinfected animals. As this colony type has been associated with pneumococcal biofilms, the impact of coinfection on pneumococcal biofilm formation was investigated. The results clearly show enhanced biofilm formation in vitro by pneumococci in the presence of H. influenzae. Conclusions Based on these data, we conclude that coinfection with H. influenzae facilitates pneumococcal biofilm formation and persistence on the middle-ear mucosal surface. This enhanced biofilm persistence correlates with delayed emergence of opaque colony variants within the bacterial population, and a resulting decrease in systemic infection. PMID:20715928

  15. Evaluation of recombinant protein superoxide dismutase of Haemophilus parasuis strain SH0165 as vaccine candidate in a mouse model.

    PubMed

    Guo, Ling; Xu, Lei; Wu, Tao; Fu, Shulin; Qiu, Yinsheng; Hu, Chien-An Andy; Ren, Xinglong; Liu, Rongrong; Ye, Mengdie

    2017-04-01

    Haemophilus parasuis can cause a severe membrane inflammation disorder. It has been documented that superoxide dismutase (SOD) is a potential target to treat systemic inflammatory diseases. Therefore, we constructed an experimental H. parasuis subunit vaccine SOD and determined the protective efficacy of SOD using a lethal dose challenge against H. parasuis serovar 4 strain MD0322 and serovar 5 strain SH0165 in a mouse model. The results demonstrated that SOD could induce a strong humoral immune response in mice and provide significant immunoprotection efficacy against a lethal dose of H. parasuis serovar 4 strain MD0322 or serovar 5 strain SH0165 challenge. IgG subtype analysis indicated SOD protein could trigger a bias toward a Th1-type immune response and induce the proliferation of splenocytes and secretion of IL-2 and IFN-γ of splenocytes. In addition, serum in mice from the SOD-immunized group could inhibit the growth of strain MD0322 and strain SH0165 in the whole-blood killing bacteria assay. This is the first report that immunization of mice with SOD protein could provide protective effect against a lethal dose of H. parasuis serovar 4 and serovar 5 challenge in mice, which may provide a novel approach against heterogeneous serovar infection of H. parasuis in future.

  16. Epidemiology of paediatric meningitis in central Côte d'Ivoire after the implementation of Haemophilus influenzae type b vaccination.

    PubMed

    Touré, Fidèle S; Kouame, Samson; Tia, Honoré; Monemo, Pacôme; Cissé, Amadou; Diané, Bamourou; Becker, Sören L; Akoua-Koffi, Chantal

    2017-07-01

    Infectious meningitis accounts for enormous morbidity worldwide, but there is a paucity of data on its regional epidemiology in resource-constrained settings of sub-Saharan Africa. Here, we present a study on the aetiology of paediatric meningitis in central Côte d'Ivoire. Between June 2012 and December 2013, all cerebrospinal fluid (CSF) samples drawn at the University Teaching Hospital Bouaké were examined for the presence of bacterial and fungal pathogens. A causative agent was detected in 31 out of 833 CSF specimens (3.7%), with the most prevalent pathogens being Streptococcus pneumoniae (n=15) and Neisseria meningitidis (n=5). With the exception of neonates, these two bacteria were the most common agents in all age groups. Of note, only a single case of Haemophilus influenzae meningitis was detected. Hence, this study reports a considerable shift in the epidemiology of paediatric meningitis in central Côte d'Ivoire. Following the implementation of a nation-wide childhood vaccination programme against H. influenzae type b, this pathogen was much less frequently reported than in previous studies. The integration of specific vaccines against S. pneumoniae and N. meningitidis into the childhood vaccination programme in Côted'Ivoire holds promise to further reduce the burden due to infectious meningitis.

  17. The cytolethal distending toxin from the chancroid bacterium Haemophilus ducreyi induces cell-cycle arrest in the G2 phase.

    PubMed

    Cortes-Bratti, X; Chaves-Olarte, E; Lagergård, T; Thelestam, M

    1999-01-01

    The potent cytolethal distending toxin produced by Haemophilus ducreyi is a putative virulence factor in the pathogenesis of chancroid. We studied its action on eukaryotic cells, with the long-term goal of understanding the pathophysiology of the disease. Intoxication of cultured human epithelial-like cells, human keratinocytes, and hamster fibroblasts was irreversible, and appeared as a gradual distention of three- to fivefold the size of control cells. Organized actin assemblies appeared concomitantly with cell enlargement, promoted by a mechanism that probably does not involve small GTPases of the Rho protein family. Intoxicated cells did not proliferate. Similar to cells treated with other cytolethal distending toxins, these cells accumulated in the G2 phase of the cell cycle, demonstrating an increased level of the tyrosine phosphorylated (inactive) form of the cyclin-dependent kinase p34(cdc2). DNA synthesis was not affected until several hours after this increase, suggesting that the toxin acts directly on some kinase/phosphatase in the signaling network controlling the p34(cdc2) activity. We propose that this toxin has an important role both in the generation of chancroid ulcers and in their slow healing. The toxin may also be an interesting new tool for molecular studies of the eukaryotic cell- cycle machinery.

  18. The cytolethal distending toxin from the chancroid bacterium Haemophilus ducreyi induces cell-cycle arrest in the G2 phase

    PubMed Central

    Cortes-Bratti, Ximena; Chaves-Olarte, Esteban; Lagergård, Teresa; Thelestam, Monica

    1999-01-01

    The potent cytolethal distending toxin produced by Haemophilus ducreyi is a putative virulence factor in the pathogenesis of chancroid. We studied its action on eukaryotic cells, with the long-term goal of understanding the pathophysiology of the disease. Intoxication of cultured human epithelial-like cells, human keratinocytes, and hamster fibroblasts was irreversible, and appeared as a gradual distention of three- to fivefold the size of control cells. Organized actin assemblies appeared concomitantly with cell enlargement, promoted by a mechanism that probably does not involve small GTPases of the Rho protein family. Intoxicated cells did not proliferate. Similar to cells treated with other cytolethal distending toxins, these cells accumulated in the G2 phase of the cell cycle, demonstrating an increased level of the tyrosine phosphorylated (inactive) form of the cyclin-dependent kinase p34cdc2. DNA synthesis was not affected until several hours after this increase, suggesting that the toxin acts directly on some kinase/phosphatase in the signaling network controlling the p34cdc2 activity. We propose that this toxin has an important role both in the generation of chancroid ulcers and in their slow healing. The toxin may also be an interesting new tool for molecular studies of the eukaryotic cell- cycle machinery. PMID:9884340

  19. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains

    PubMed Central

    Gangaiah, Dharanesh; Webb, Kristen M.; Humphreys, Tricia L.; Fortney, Kate R.; Toh, Evelyn; Tai, Albert; Katz, Samantha S.; Pillay, Allan; Chen, Cheng-Yen; Roberts, Sally A.; Munson, Robert S.; Spinola, Stanley M.

    2015-01-01

    Background Although cutaneous ulcers (CU) in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU) and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin? Methodology/Principal Findings To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya) and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin. Conclusions/Significance These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions. PMID:26147869

  20. Immunization against Haemophilus Influenzae Type b in Iran; Cost-utility and Cost-benefit Analyses

    PubMed Central

    Moradi-Lakeh, Maziar; Shakerian, Sareh; Esteghamati, Abdoulreza

    2012-01-01

    Background: Haemophilus Influenzae type b (Hib) is an important cause of morbidity and mortality in children. Although its burden is considerably preventable by vaccine, routine vaccination against Hib has not been defined in the National Immunization Program of Iran. This study was performed to assess the cost-benefit and cost-utility of running an Hib vaccination program in Iran. Methods: Based on a previous systematic review and meta-analysis for vaccine efficacy, we estimated the averted DALYs (Disability adjusted life years) and cost-benefit of vaccination. Different acute invasive forms of Hib infection and the permanent sequels were considered for estimating the attributed DALYs. We used a societal perspective for economic evaluation and included both direct and indirect costs of alternative options about vaccination. An annual discount rate of 3% and standard age-weighting were used for estimation. To assess the robustness of the results, a sensitivity analysis was performed. Results: The incidence of Hib infection was estimated 43.0 per 100000, which can be reduced to 6.7 by vaccination. Total costs of vaccination were estimated at US$ 15,538,129. Routine vaccination of the 2008 birth cohort would prevent 4079 DALYs at a cost per averted-DALY of US$ 4535. If we consider parents’ loss of income and future productivity loss of children, it would save US$ 8,991,141, with a benefit-cost ratio of 2.14 in the base-case analysis. Sensitivity analysis showed a range of 0.78 to 3.14 for benefit-to-cost ratios. Conclusion: Considering costs per averted DALY, vaccination against Hib is a cost-effective health intervention in Iran, and allocating resources for routine vaccination against Hib seems logical. PMID:22708030

  1. Immunogenicity and protective efficacy of recombinant Haemophilus parasuis SH0165 putative outer membrane proteins.

    PubMed

    Fu, Shulin; Zhang, Minmin; Xu, Juan; Ou, Jiwen; Wang, Yan; Liu, Huazhen; Liu, Jinlin; Chen, Huanchun; Bei, Weicheng

    2013-01-02

    Haemophilus parasuis (H. parasuis), the causative agent of swine polyserositis, polyarthritis, and meningitis, is one of the most important bacterial diseases of pigs worldwide. Little vaccines currently exist that have a significant effect on infections with all pathogenic serovars of H. parasuis. H. parasuis putative outer membrane proteins (OMPs) are potentially essential components of more effective vaccines. Recently, the genomic sequence of H. parasuis serovar 5 strain SH0165 was completed in our laboratory, which allow us to target OMPs for the development of recombinant vaccines. In this study, we focused on 10 putative OMPs and all the putative OMPs were cloned, expressed and purified as HIS fusion proteins. Primary screening for immunoprotective potential was performed in mice challenged with an LD50 challenge. Out of these 10 OMPs three fusion proteins rGAPDH, rOapA, and rHPS-0675 were found to be protective in a mouse model of H. parasuis infection. We further evaluated the immune responses and protective efficacy of rGAPDH, rOapA, and rHPS-0675 in pig models. All three proteins elicited humoral antibody responses and conferred different levels of protection against challenge with a lethal dose of H. parasuis SH0165 in pig models. In addition, the antisera against the three individual proteins and the synergistic protein efficiently inhibited bacterial growth in a whole blood assay. The data demonstrated that the three proteins showed high value individually and the combination of rGAPDH, rOapA, and rHPS-0675 offered the best protection. Our results indicate that rGAPDH, rOapA, and rHPS-0675 induced protection against H. parasuis SH0165 infection, which may facilitate the development of a multi-component vaccine. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Immune response to oligopeptide permease A (OppA) protein in pigs naturally and experimentally infected with Haemophilus parasuis.

    PubMed

    Macedo, Nubia; Oliveira, Simone; Torremorell, Montserrat; Rovira, Albert

    2016-08-01

    Haemophilus parasuis is an important swine pathogen that causes Glasser's disease, characterized by pneumonia, polyserositis and meningitis. Protection against H. parasuis infection is associated with the presence of homologous antibodies in serum. However, a H. parasuis antigen that can elicit a protective immune response against all H. parasuis strains has yet to be found. A novel immunogenic and species-specific H. parasuis protein was identified by screening H. parasuis whole cell proteins using swine convalescent sera. One protein of 52kDa was clearly immunodominant and conserved among different H. parasuis strains. This protein was further identified as an oligopeptide permease A (OppA). Because OppA elicited a specific antibody response in pigs that recovered from H. parasuis infection, we investigated its potential role in diagnostics and protective immunity. An ELISA test using recombinant OppA (rOppA) as its coating antigen was further developed and tested. H. parasuis specific antibodies to rOppA were detected in serum from convalescent pigs but not in serum from specific pathogen free (SPF) or conventional pigs. Pigs immunized with rOppA protein had robust serological responses. However, the antibodies were not protective against challenge infection. We conclude that OppA is a universal species-specific H. parasuis immunogen, and a good marker for previous systemic infection with H. parasuis. Copyright © 2016. Published by Elsevier Ltd.

  3. Immunization with the Haemophilus ducreyi hemoglobin receptor HgbA protects against infection in the swine model of chancroid.

    PubMed

    Afonina, Galyna; Leduc, Isabelle; Nepluev, Igor; Jeter, Chrystina; Routh, Patty; Almond, Glen; Orndorff, Paul E; Hobbs, Marcia; Elkins, Christopher

    2006-04-01

    The etiologic agent of chancroid is Haemophilus ducreyi. To fulfill its obligate requirement for heme, H. ducreyi uses two TonB-dependent receptors: the hemoglobin receptor (HgbA) and a receptor for free heme (TdhA). Expression of HgbA is necessary for H. ducreyi to survive and initiate disease in a human model of chancroid. In this study, we used a swine model of H. ducreyi infection to demonstrate that an experimental HgbA vaccine efficiently prevents chancroid, as determined by several parameters. Histological sections of immunized animals lacked typical microscopic features of chancroid. All inoculated sites from mock-immunized pigs yielded viable H. ducreyi cells, whereas no viable H. ducreyi cells were recovered from inoculated sites of HgbA-immunized pigs. Antibodies from sera of HgbA-immunized animals bound to and initiated antibody-dependent bactericidal activity against homologous H. ducreyi strain 35000HP and heterologous strain CIP542 ATCC; however, an isogenic hgbA mutant of 35000HP was not killed, proving specificity. Anti-HgbA immunoglobulin G blocked hemoglobin binding to the HgbA receptor, suggesting a novel mechanism of protection through the limitation of heme/iron acquisition by H. ducreyi. Such a vaccine strategy might be applied to other bacterial pathogens with strict heme/iron requirements. Taken together, these data suggest continuing the development of an HgbA subunit vaccine to prevent chancroid.

  4. Immunization with the Haemophilus ducreyi Hemoglobin Receptor HgbA Protects against Infection in the Swine Model of Chancroid

    PubMed Central

    Afonina, Galyna; Leduc, Isabelle; Nepluev, Igor; Jeter, Chrystina; Routh, Patty; Almond, Glen; Orndorff, Paul E.; Hobbs, Marcia; Elkins, Christopher

    2006-01-01

    The etiologic agent of chancroid is Haemophilus ducreyi. To fulfill its obligate requirement for heme, H. ducreyi uses two TonB-dependent receptors: the hemoglobin receptor (HgbA) and a receptor for free heme (TdhA). Expression of HgbA is necessary for H. ducreyi to survive and initiate disease in a human model of chancroid. In this study, we used a swine model of H. ducreyi infection to demonstrate that an experimental HgbA vaccine efficiently prevents chancroid, as determined by several parameters. Histological sections of immunized animals lacked typical microscopic features of chancroid. All inoculated sites from mock-immunized pigs yielded viable H. ducreyi cells, whereas no viable H. ducreyi cells were recovered from inoculated sites of HgbA-immunized pigs. Antibodies from sera of HgbA-immunized animals bound to and initiated antibody-dependent bactericidal activity against homologous H. ducreyi strain 35000HP and heterologous strain CIP542 ATCC; however, an isogenic hgbA mutant of 35000HP was not killed, proving specificity. Anti-HgbA immunoglobulin G blocked hemoglobin binding to the HgbA receptor, suggesting a novel mechanism of protection through the limitation of heme/iron acquisition by H. ducreyi. Such a vaccine strategy might be applied to other bacterial pathogens with strict heme/iron requirements. Taken together, these data suggest continuing the development of an HgbA subunit vaccine to prevent chancroid. PMID:16552053

  5. Comparison of Haemophilus parasuis reference strains and field isolates by using random amplified polymorphic DNA and protein profiles

    PubMed Central

    2012-01-01

    Background Haemophilus parasuis is the causative agent of Glässer’s disease and is a pathogen of swine in high-health status herds. Reports on serotyping of field strains from outbreaks describe that approximately 30% of them are nontypeable and therefore cannot be traced. Molecular typing methods have been used as alternatives to serotyping. This study was done to compare random amplified polymorphic DNA (RAPD) profiles and whole cell protein (WCP) lysate profiles as methods for distinguishing H. parasuis reference strains and field isolates. Results The DNA and WCP lysate profiles of 15 reference strains and 31 field isolates of H. parasuis were analyzed using the Dice and neighbor joining algorithms. The results revealed unique and reproducible DNA and protein profiles among the reference strains and field isolates studied. Simpson’s index of diversity showed significant discrimination between isolates when three 10mer primers were combined for the RAPD method and also when both the RAPD and WCP lysate typing methods were combined. Conclusions The RAPD profiles seen among the reference strains and field isolates did not appear to change over time which may reflect a lack of DNA mutations in the genes of the samples. The recent field isolates had different WCP lysate profiles than the reference strains, possibly because the number of passages of the type strains may affect their protein expression. PMID:22703293

  6. Trends in Haemophilus influenzae type b infections in adults in England and Wales: surveillance study

    PubMed Central

    McVernon, Jodie; Trotter, Caroline L; Slack, Mary P E; Ramsay, Mary E

    2004-01-01

    Objective To describe invasive Haemophilus influenzae type b (Hib) infections in individuals aged 15 years or older in England and Wales between 1991 and 2003. Design Prospective, laboratory based surveillance of invasive Hib infections and cross sectional seroprevalence study. Setting England and Wales. Participants Cases were confirmed by isolation of H influenzae from a normally sterile site, or from a non-sterile site in cases with a diagnosis of epiglottitis. Excess serum samples collected from English 30-39 year olds as part of a national serosurvey were identified for the years 1990, 1994, 1997, 2000, and 2002. Main outcome measures The number of invasive Hib infections from 1991 to 2003. Population immunity to H influenzae type b in English adults was also measured. Results After routine infant immunisation was introduced in October 1992, adult Hib infections decreased initially but then rose from a low in 1998 to reach prevaccine levels in 2003. An associated fall in median Hib antibody concentrations occurred, from 1.29 μg/ml (95% confidence interval 0.90 to 1.64) in 1991 to 0.70 μg/ml (0.57 to 0.89) in 1994 (P = 0.006), with no significant change observed thereafter. Conclusions Although immunisation of infants resulted in an initial decline in Hib infections in adults, a resurgence in reported cases occurred in 2002-3. This rise was associated with an increase in cases in children and evidence of reduced immunity in older unimmunised cohorts. Childhood immunisation programmes may have unanticipated effects on the epidemiology of disease in older age groups, and surveillance strategies must be targeted at entire populations. PMID:15374916

  7. Impact of Haemophilus influenzae type b conjugate vaccine on bacterial meningitis in the Dominican Republic.

    PubMed

    Lee, Ellen H; Corcino, Miriam; Moore, Arelis; Garib, Zacarias; Peña, Chabela; Sánchez, Jacqueline; Fernández, Josefina; Feris-Iglesias, Jesús M; Flannery, Brendan

    2008-09-01

    Widespread use of Haemophilus influenzae type b (Hib) vaccines has dramatically reduced the burden of Hib disease throughout the Americas. Few studies have evaluated the impact of Hib vaccination on non-culture-confirmed disease. This study analyzed trends in probable bacterial meningitis before and after the introduction of Hib vaccine in the Dominican Republic and estimated vaccine effectiveness against Hib meningitis. Meningitis cases among children < 5 years of age were identified from admission records of the main pediatric hospital in Santo Domingo during 1998-2004. Laboratory criteria were used to classify meningitis cases with probable bacterial etiology; confirmed cases had positive bacterial culture or antigen detection in cerebrospinal fluid. Cumulative incidence rates of confirmed and probable bacterial meningitis were calculated for children living in the National District. Confirmed cases of Hib meningitis were enrolled in a case-control study with age- and neighborhood-matched control children to calculate vaccine effectiveness. Before vaccine introduction, annual rates of meningitis with probable bacterial etiology were 49 cases per 100 000 children < 5 years old; Hib accounted for 60% of confirmed bacterial cases. During 2002-2004, after vaccine introduction, annual rates of probable bacterial meningitis were 65% lower at 16 cases per 100 000, and Hib accounted for 26% of confirmed cases. Rates of Hib meningitis and probable bacterial meningitis with no determined etiology declined by 13 and 17 cases per 100 000, respectively. Introduction of Hib vaccine substantially reduced the incidence of confirmed and probable bacterial meningitis in the Dominican Republic. The estimated impact of Hib vaccination was twice as great when non-culture-confirmed disease was included.

  8. Antimicrobial resistance genes in Actinobacillus pleuropneumoniae, Haemophilus parasuis and Pasteurella multocida isolated from Australian pigs.

    PubMed

    Dayao, Dae; Gibson, J S; Blackall, P J; Turni, C

    2016-07-01

    To identify genes associated with the observed antimicrobial resistance in Actinobacillus pleuropneumoniae, Haemophilus parasuis and Pasteurella multocida isolated from Australian pigs. Isolates with known phenotypic resistance to β-lactams, macrolides and tetracycline were screened for the presence of antimicrobial resistance genes. A total of 68 A. pleuropneumoniae, 62 H. parasuis and 20 P. multocida isolates exhibiting phenotypic antimicrobial resistance (A. pleuropneumoniae and P. multocida) or elevated minimal inhibitory concentrations (MICs) (H. parasuis) to any of the following antimicrobial agents - ampicillin, erythromycin, penicillin, tetracycline, tilmicosin and tulathromycin - were screened for a total of 19 associated antimicrobial resistance genes (ARGs) by PCR. The gene bla ROB-1 was found in all ampicillin- and penicillin-resistant isolates, but none harboured the bla TEM-1 gene. The tetB gene was found in 76% (74/97) of tetracycline-resistant isolates, 49/53 A. pleuropneumoniae, 17/30 H. parasuis and 8/14 P. multocida. One A. pleuropneumoniae isolate harboured the tetH gene, but none of the 97 isolates had tetA, tetC, tetD, tetE, tetL, tetM or tetO. A total of 92 isolates were screened for the presence of macrolide resistance genes. None was found to have ermA, ermB, ermC, erm42, mphE, mefA, msrA or msrE. The current study has provided a genetic explanation for the resistance or elevated MIC of the majority of isolates of Australian porcine respiratory pathogens to ampicillin, penicillin and tetracycline. However, the macrolide resistance observed by phenotypic testing remains genetically unexplained and further studies are required. © 2016 Australian Veterinary Association.

  9. Economic evaluation of delivering Haemophilus influenzae type b vaccine in routine immunization services in Kenya.

    PubMed

    Akumu, Angela Oloo; English, Mike; Scott, J Anthony G; Griffiths, Ulla K

    2007-07-01

    Haemophilus influenzae type b (Hib) vaccine was introduced into routine immunization services in Kenya in 2001. We aimed to estimate the cost-effectiveness of Hib vaccine delivery. A model was developed to follow the Kenyan 2004 birth cohort until death, with and without Hib vaccine. Incidence of invasive Hib disease was estimated at Kilifi District Hospital and in the surrounding demographic surveillance system in coastal Kenya. National Hib disease incidence was estimated by adjusting incidence observed by passive hospital surveillance using assumptions about access to care. Case fatality rates were also assumed dependent on access to care. A price of US$ 3.65 per dose of pentavalent diphtheria-tetanus-pertussis-hep B-Hib vaccine was used. Multivariate Monte Carlo simulations were performed in order to assess the impact on the cost-effectiveness ratios of uncertainty in parameter values. The introduction of Hib vaccine reduced the estimated incidence of Hib meningitis per 100,000 children aged < 5 years from 71 to 8; of Hib non-meningitic invasive disease from 61 to 7; and of non-bacteraemic Hib pneumonia from 296 to 34. The costs per discounted disability adjusted life year (DALY) and per discounted death averted were US$ 38 (95% confidence interval, CI: 26-63) and US$ 1197 (95% CI: 814-2021) respectively. Most of the uncertainty in the results was due to uncertain access to care parameters. The break-even pentavalent vaccine price--where incremental Hib vaccination costs equal treatment costs averted from Hib disease--was US$ 1.82 per dose. Hib vaccine is a highly cost-effective intervention in Kenya. It would be cost-saving if the vaccine price was below half of its present level.

  10. Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

    PubMed

    An, So Jung; Woo, Joo Sung; Chae, Myung Hwa; Kothari, Sudeep; Carbis, Rodney

    2015-03-24

    The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg. When conjugation was performed without the ADH spacer the induction of an anti-PRP response was equivalent to that seen by conjugate with the ADH spacer, however, a negligible anti-HBsAg response was induced. For comparison, PRP was conjugated to diphtheria toxoid (DT) and Vi polysaccharide purified from Salmonella Typhi conjugated to HBsAg both using an ADH spacer. The PRPAH-DT conjugate induced strong anti-PRP and anti-DT responses, the Vi-AHHBsAg conjugate induced a good anti-HBsAg response but not as strong as that induced by the PRPAH-HBsAg conjugate. This study demonstrated that in mice it was possible to induce robust antibody responses to both polysaccharide and carrier protein provided the conjugate has certain physico-chemical properties. A PRPAH-HBsAg conjugate with the capacity to induce anti-PRP and anti-HBsAg responses could be incorporated into a multivalent pediatric vaccine and simplify formulation of such a vaccine. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Overexpression and Purification of C-terminal Fragment of the Passenger Domain of Hap Protein from Nontypeable Haemophilus influenzae in a Highly Optimized Escherichia coli Expression System

    PubMed Central

    Tabatabaee, Akram; Siadat, Seyed Davar; Moosavi, Seyed Fazllolah; Aghasadeghi, Mohammad Reza; Memarnejadian, Arash; Pouriayevali, Mohammad Hassan; Yavari, Neda

    2013-01-01

    Background Nontypeable Haemophilus influenzae (NTHi) is a common cause of respiratory tract disease and initiates infection by colonization in nasopharynx. The Haemophilus influenzae (H. influenzae) Hap adhesin is an auto transporter protein that promotes initial interaction with human epithelial cells. Hap protein contains a 110 kDa internal passenger domain called “HapS” and a 45 kDa C-terminal translocator domain called “Hapβ”. Hap adhesive activity has been recently reported to be connected to its Cell Binding Domain (CBD) which resides within the 311 C-terminal residues of the internal passenger domain of the protein. Furthermore, immunization with this CBD protein has been shown to prevent bacterial nasopharynx colonization in animal models. Methods To provide enough amounts of pure HapS protein for vaccine studies, we sought to develop a highly optimized system to overexpress and purify the protein in large quantities. To this end, pET24a-cbd plasmid harboring cbd sequence from NTHi ATCC49766 was constructed and its expression was optimized by testing various expression parameters such as growth media, induction temperature, IPTG inducer concentration, induction stage and duration. SDS-PAGE and Western-blotting were used for protein analysis and confirmation and eventually the expressed protein was easily purified via immobilized metal affinity chromatography (IMAC) using Ni-NTA columns. Results The highest expression level of target protein was achieved when CBD expressing E. coli BL21 (DE3) cells were grown at 37°C in 2xTY medium with 1.0 mM IPTG at mid-log phase (OD600 nm equal to 0.6) for 5 hrs. Amino acid sequence alignment of expressed CBD protein with 3 previously published CBD amino acid sequences were more than %97 identical and antigenicity plot analysis further revealed 9 antigenic domains which appeared to be well conserved among different analyzed CBD sequences. Conclusion Due to the presence of high similarity among CBD from NTHi ATCC

  12. Emergence and Disappearance of a Virulent Clone of Haemophilus influenzae Biogroup aegyptius, Cause of Brazilian Purpuric Fever

    PubMed Central

    Harrison, Lee H.; Simonsen, Vera; Waldman, Eliseu A.

    2008-01-01

    Summary: In 1984, children presented to the emergency department of a hospital in the small town of Promissão, São Paulo State, Brazil, with an acute febrile illness that rapidly progressed to death. Local clinicians and public health officials recognized that these children had an unusual illness, which led to outbreak investigations conducted by Brazilian health officials in collaboration with the U.S. Centers for Disease Control and Prevention. The studies that followed are an excellent example of the coordinated and parallel studies that are used to investigate outbreaks of a new disease, which became known as Brazilian purpuric fever (BPF). In the first outbreak investigation, a case-control study confirmed an association between BPF and antecedent conjunctivitis but the etiology of the disease could not be determined. In a subsequent outbreak, children with BPF were found to have bacteremia caused by Haemophilus influenzae biogroup aegyptius (H. aegyptius), an organism previously known mainly to cause self-limited purulent conjunctivitis. Molecular characterization of blood and other isolates demonstrated the clonal nature of the H. aegyptius strains that caused BPF, which were genetically distant from the diverse strains that cause only conjunctivitis. This led to an intense effort to identify the factors causing the unusual invasiveness of the BPF clone, which has yet to definitively identify the virulence factor or factors involved. After a series of outbreaks and sporadic cases through 1993, no additional cases of BPF have been reported. PMID:18854482

  13. Experimental design to optimize an Haemophilus influenzae type b conjugate vaccine made with hydrazide-derivatized tetanus toxoid.

    PubMed

    Laferriere, Craig; Ravenscroft, Neil; Wilson, Seanette; Combrink, Jill; Gordon, Lizelle; Petre, Jean

    2011-10-01

    The introduction of type b Haemophilus influenzae conjugate vaccines into routine vaccination schedules has significantly reduced the burden of this disease; however, widespread use in developing countries is constrained by vaccine costs, and there is a need for a simple and high-yielding manufacturing process. The vaccine is composed of purified capsular polysaccharide conjugated to an immunogenic carrier protein. To improve the yield and rate of the reductive amination conjugation reaction used to make this vaccine, some of the carboxyl groups of the carrier protein, tetanus toxoid, were modified to hydrazides, which are more reactive than the ε -amine of lysine. Other reaction parameters, including the ratio of the reactants, the size of the polysaccharide, the temperature and the salt concentration, were also investigated. Experimental design was used to minimize the number of experiments required to optimize all these parameters to obtain conjugate in high yield with target characteristics. It was found that increasing the reactant ratio and decreasing the size of the polysaccharide increased the polysaccharide:protein mass ratio in the product. Temperature and salt concentration did not improve this ratio. These results are consistent with a diffusion controlled rate limiting step in the conjugation reaction. Excessive modification of tetanus toxoid with hydrazide was correlated with reduced yield and lower free polysaccharide. This was attributed to a greater tendency for precipitation, possibly due to changes in the isoelectric point. Experimental design and multiple regression helped identify key parameters to control and thereby optimize this conjugation reaction.

  14. Haemophilus parasuis CpxRA two-component system confers bacterial tolerance to environmental stresses and macrolide resistance.

    PubMed

    Cao, Qi; Feng, Fenfen; Wang, Huan; Xu, Xiaojuan; Chen, Huanchun; Cai, Xuwang; Wang, Xiangru

    2018-01-01

    Haemophilus parasuis is an opportunistic pathogen localized in the upper respiratory tracts of pigs, its infection begins from bacterial survival under complex conditions, like hyperosmosis, oxidative stress, phagocytosis, and sometimes antibiotics as well. The two-component signal transduction (TCST) system serves as a common stimulus-response mechanism that allows microbes to sense and respond to diverse environmental conditions via a series of phosphorylation reactions. In this study, we investigated the role of TCST system CpxRA in H. parasuis in response to different environmental stimuli by constructing the ΔcpxA and ΔcpxR single deletion mutants as well as the ΔcpxRA double deletion mutant from H. parasuis serotype 4 isolate JS0135. We demonstrated that H. parasuis TCST system CpxRA confers bacterial tolerance to stresses and bactericidal antibiotics. The CpxR was found to play essential roles in mediating oxidative stress, osmotic stresses and alkaline pH stress tolerance, as well as macrolide resistance (i.e. erythromycin), but the CpxA deletion did not decrease bacterial resistance to abovementioned stresses. Moreover, we found via RT-qPCR approach that HAPS_RS00160 and HAPS_RS09425, both encoding multidrug efflux pumps, were significantly decreased in erythromycin challenged ΔcpxR and ΔcpxRA mutants compared with wild-type strain JS0135. These findings characterize the role of the TCST system CpxRA in H. parasuis conferring stress response tolerance and bactericidal resistance, which will deepen our understanding of the pathogenic mechanism in H. parasuis. Copyright © 2017 Elsevier GmbH. All rights reserved.

  15. Evidence of the presence of nucleic acids and β-glucan in the matrix of non-typeable Haemophilus influenzae in vitro biofilms

    PubMed Central

    Domenech, Mirian; Pedrero-Vega, Elena; Prieto, Alicia; García, Ernesto

    2016-01-01

    Non-typeable Haemophilus influenzae (NTHi) is a Gram-negative bacterium that frequently colonizes the human nasopharynx; it is a common cause of chronic and recurrent otitis media in children and of exacerbations of chronic obstructive pulmonary disease. To date, no exopolysaccharide clearly contributing to NTHi biofilms has been identified. Consequently, there is some debate as to whether NTHi forms biofilms during colonization and infection. The present work shows that NTHi can form biofilms in vitro, producing an extracellular matrix composed of proteins, nucleic acids, and a β-glucan. Extracellular DNA, visualized by immunostaining and using fluorochromes, is an important component of this matrix and appears to be essential in biofilm maintenance. Extracellular RNA appears to be required only in the first steps of biofilm formation. Evidence of a matrix polysaccharide was obtained by staining with Calcofluor white M2R and by disaggregating biofilms with cellulase. Using strain 54997, residues of Glcp(1→4) in the NTHi biofilm were confirmed by gas-liquid chromatography-mass spectrometry. Evidence that N-acetyl-L-cysteine shows notable killing activity towards in vitro NTHi biofilm-forming bacteria is also provided. PMID:27805043

  16. Evidence of the presence of nucleic acids and β-glucan in the matrix of non-typeable Haemophilus influenzae in vitro biofilms.

    PubMed

    Domenech, Mirian; Pedrero-Vega, Elena; Prieto, Alicia; García, Ernesto

    2016-11-02

    Non-typeable Haemophilus influenzae (NTHi) is a Gram-negative bacterium that frequently colonizes the human nasopharynx; it is a common cause of chronic and recurrent otitis media in children and of exacerbations of chronic obstructive pulmonary disease. To date, no exopolysaccharide clearly contributing to NTHi biofilms has been identified. Consequently, there is some debate as to whether NTHi forms biofilms during colonization and infection. The present work shows that NTHi can form biofilms in vitro, producing an extracellular matrix composed of proteins, nucleic acids, and a β-glucan. Extracellular DNA, visualized by immunostaining and using fluorochromes, is an important component of this matrix and appears to be essential in biofilm maintenance. Extracellular RNA appears to be required only in the first steps of biofilm formation. Evidence of a matrix polysaccharide was obtained by staining with Calcofluor white M2R and by disaggregating biofilms with cellulase. Using strain 54997, residues of Glcp(1→4) in the NTHi biofilm were confirmed by gas-liquid chromatography-mass spectrometry. Evidence that N-acetyl-L-cysteine shows notable killing activity towards in vitro NTHi biofilm-forming bacteria is also provided.

  17. [Incidence of meningitis caused by Haemophilus influenzae in the state of Rio Grande do Sul 1999-2010: impact of vaccination campaign].

    PubMed

    Schossler, João Guilherme Stadler; Beck, Sandra Trevisan; de Campos, Marli Matiko Anraku; Farinha, Lourdes Boufleur

    2013-05-01

    This article seeks to analyze and update the epidemiological situation of meningitis caused by Haemophilus influenzae type b in the past 10 years in the state of Rio Grande do Sul (RS). It is a retrospective, descriptive study, which used the data notification system of meningitis and vaccination campaign coverage, stored in the Epidemiological TABNET online database, for the period from 1999 to 2010. Cases notified and confirmed were used and the selection criteria were the year when the symptoms were detected, age, diagnosis, and evolution. Nineteen health centers in the state of Rio Grande do Sul were analyzed. The z-test was used to evaluate comparisons between the proportions. In the period studied, 3043 confirmed cases of bacterial meningitis were reported, of which 6.77% were caused by H. influenzae. The incidence and mortality rates of meningitis caused by H. influenzae, without taking age group into consideration, fell significantly (95.6%) after 1999. Children under one year old continue to be the most affected (52%), there being no change in lethality. The results presented revealed a positive impact of Hib vaccination strategies in the state of Rio Grande do Sul over the past ten years.

  18. Histopathologic lesions in conventional pigs experimentally infected with Haemophilus parasuis serovar 5.

    PubMed

    Palzer, A; Austin-Busse, R-L; Ladinig, A; Balka, G; Zoels, S; Ritzmann, M

    2015-01-01

    In the present study various tissues of pigs were investigated for the presence of histopathologic lesions after an experimental infection with Haemophilus (H.) parasuis serovar 5. Conventional pigs (n = 36) were divided into a control group B (n = 9) and a challenge group A (n = 27), which was infected intratracheally. Pigs that did not die prior to study termination were euthanized on day 14 post inoculation. Postmortem samples of the lung, heart, liver, kidney, spleen, left tarsal joint capsule and brain were collected. All but one pig with detectable histopathologic lesions (n = 11) showed typical macroscopic changes. Histopathologic examination of all tissue samples identified pyelitis (n = 10), synovitis (n = 7) and meningitis (n = 7) and all those animals were euthanized prior to study termination. No histopathologic lesions were found in pigs of the control group. The correlations between pyelitis and meningitis, pyelitis and synovitis and synovitis and meningitis were significant (p < 0.001). No significant correlation could be observed between the histopathologic and the clinical examination of the joints. The investigation of samples from the joints by PCR was not significantly correlated with the observed synovitis. The clinical observation of neurologic signs was significantly correlated with meningitis (p = 0.03). A significant correlation (p < 0.001) could be detected between meningitis and the detection of H. parasuis by PCR in brain samples. H. parasuis constantly causes clinical signs and pathologic lesions as soon as it infects the brain while it can infect the joints without causing histopathologic lesions. Pigs with histopathologic lesions do not always show typical clinical signs. Only few studies described the finding of kidney lesions in pigs with Glässer's disease and this is the first study to describe a pyelitis in pigs experimentally infected with H. parasuis. The observed pyelitis mainly occurred in acute cases.

  19. Haemophilus influenzae type b (Hib) seroprevalence and current epidemiology in England and Wales.

    PubMed

    Collins, Sarah; Litt, David; Almond, Rachael; Findlow, Jamie; Linley, Ezra; Ramsay, Mary; Borrow, Ray; Ladhani, Shamez

    2018-04-01

    The implementation of the Hib conjugate vaccine in the United Kingdom in 1992 resulted in a rapid decline in invasive Hib disease across all age groups. However, a resurgence in 2000-2002 prompted the introduction of additional control measures, including a routine 12-month booster in 2006. Here we describe results from a national serosurvey in children eligible for the 12-month booster and recent Haemophilus influenzae epidemiology in England and Wales. A national serosurvey was performed to determine the prevalence of anti-polyribosyl-phosphate (anti-PRP) IgG antibodies in 1000 residual samples from children up to 8 years of age in 2013-2014. Data were compared to previous national serosurveys performed by the same laboratory. Current epidemiology of invasive H. influenzae disease in England and Wales is also reported. Median anti-PRP IgG concentrations were highest among 1 year olds at 4.4 µg/mL (IQR, 1.3-14.9; n = 99) and then declined rapidly but remained ≥1.0 µg/mL across the age-groups in the cohort eligible for the 12-month booster. Overall, 89% of children (719/817) had anti-PRP concentrations ≥0.15 µg/mL, the putative threshold for short-term protection against invasive Hib disease. During 2012-2016, annual Hib disease incidence remained below one case per million population, responsible for only 67 of 3523 laboratory-confirmed H. influenzae cases, including one case of Hib meningitis during the 5-year period. There were only two deaths within 30 days over the five-year period (case fatality rate, 3.0%). Hib control in England and Wales is currently the best achieved since the vaccine was introduced more than two decades ago. However, Hib antibodies wane rapidly after the 12 months booster. Although most children remain protected against disease, antibody levels may not be high enough to prevent carriage among toddlers. Ongoing monitoring is essential to inform future vaccination policy. Copyright © 2018 The British Infection Association. All

  20. Antibiotic susceptibility profile of Haemophilus influenzae and transfer of co-trimoxazole resistance determinants.

    PubMed

    Mohd-Zain, Z; Kamsani, N H; Ismail, I S; Ahmad, N

    2012-09-01

    Prior to the implementation of Haemophilus influenzae type b vaccination worldwide, H. influenzae has been one of the main causative agents of community acquired pneumonia and meningitis in children. Due to the lack of information on the characteristics of the H. influenzae isolates that have previously been collected in Malaysia, the H. influenzae were assessed of their microbial susceptibility to commonly used antibiotics. Emphasis was made on strains that were resistance to co-trimoxazole (SXT) and their mode of transfer of the antibiotic resistance determinants were examined. A collection of 34 H. influenzae isolates was serotyped and antimicrobial susceptibility tests were performed to 11 antibiotics. To the isolates that were found to be resistant to co-trimoxazole, minimum inhibition concentration (MIC) to SXT was performed using Etest while agar dilution method was used to measure the individual MICs of trimethoprim (TMP) and sulfamethoxazole (SUL). These isolates were also examined for presence of plasmid by PCR and isolation method. Conjugal transfers of SXT-resistant genes to SXT-susceptible hosts were performed to determine their rate of transfer. Result showed that 20.6% of the total number of isolates was serotype B while the remaining was non-typeable. Antimicrobial susceptibility profile of all the isolates revealed that 58.8% was resistant to at least one antibiotic. Majority of these isolates were equally resistant to ampicillin and tetracycline (29.4% each), followed by resistance to SXT (26.5%). From nine isolates that were found to be SXT-resistant, five contained plasmid/s. Conjugal transfer experiment showed that these five isolates with plasmid transferred SXT-resistance determinants at a higher frequency than those without. From these observations, it is postulated that plasmid is not involved in the transfer of SXT-resistance genes but presence of plasmid facilitates their transfer. The information obtained from this study provides some

  1. Five-year Antibody Persistence and Safety After a Single Dose of Combined Haemophilus influenzae Type B Neisseria meningitidis Serogroup C-Tetanus Toxoid Conjugate Vaccine in Haemophilus influenzae Type B-primed Toddlers.

    PubMed

    Booy, Robert; Nolan, Terry; Reynolds, Graham; Richmond, Peter; Nissen, Michael; Marshall, Helen; Stoney, Tanya; Van Der Wielen, Marie; Kolhe, Devayani; Miller, Jacqueline M

    2015-12-01

    Antibody persistence is evaluated in healthy Australian children 4 and 5 years postvaccination with a single dose of combined Haemophilus influenzae type b-Neisseria meningitidis serogroup C tetanus toxoid conjugate vaccine (Hib-MenC-TT) compared with separately administered Hib-TT and MenC-CRM197 vaccines (Hib + MCC). This is another follow-up of a phase III, open, randomized, controlled study (NCT00326118), in which 433 Hib-primed but MenC naïve toddlers aged 12-18 months were randomized 3:1 to receive Hib-MenC-TT or Hib + MCC vaccines. Protection against (1) MenC was measured by serum bactericidal antibody assay using rabbit complement (rSBA) and (2) Hib was measured by enzyme-linked immunosorbent assay of antibodies to polyribosylribitol phosphate (anti-PRP). Study children were assessed for any potentially vaccine-related serious adverse events at each persistence study visit. The according-to-protocol cohorts for persistence at years 4 and 5 included 282 and 263 children, respectively. The percentages of children with rSBA-MenC titers ≥1:8 at years 4 and 5 were 12.5% and 19.0%, respectively, in the Hib-MenC group; and 12.3% and 25.0% in the Hib + MCC group. All children in each group had anti-PRP concentrations ≥0.15 μg/mL at year 5. Exploratory analyses suggested no potential differences between groups in rSBA-MenC or anti-PRP antibody persistence. No vaccine-related serious adverse events were reported. Antibody persistence was similar for years 4 and 5 after Hib-MenC-TT or Hib + MCC vaccination, with the majority of children retaining anti-PRP antibody concentrations ≥0.15 μg/mL at both timepoints. The percentage of children retaining rSBA-MenC titers ≥1:8 was low (≤25%), suggesting that a MenC booster dose may be warranted before adolescence.

  2. [Invasive infections caused by Haemophilus influenzae type b after the institution of the conjugated vaccine on the expanded programm on immunization in Chile].

    PubMed

    Cruces R, Pablo; Donoso F, Alejandro; Camacho A, Jorge; Llorente H, Marcela

    2006-03-01

    After almost a decade since the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines in Chile (in a 2-4-6 month schedule), Hib invasive infections have dramatically decreased, albeit they remain to occasionally produce disease in pediatric patients. We report our experience with children whom developed Hib invasive disease in children since 2000 to 2004. Medical records of children with Hib were reviewed in order to describe the epidemiology, main clinical and laboratory findings, management and complications. Twenty three patients (17 male), between 1 and 71 months (median 30 months) were identified: pneumonia (7), meningitis (4), pleuropneumonia (2), empyema (2), sepsis (2), cellulitis (2), meningitis and pleuropneumonia (1), purpura fulminans (1), miositis (1) and epiglottitis (1). No deaths were observed and four patients presented severe sequelae at hospital discharge. Twenty patients were considered vaccine failures. Hib remains as a sporadic cause of severe disease in Chile and thus for physicians should still keep it in mind. Case analysis and active surveillance are necessary to monitor the current immunization regimen.

  3. Immune interaction between components of acellular pertussis-diphtheria-tetanus (DTaP) vaccine and Haemophilus influenzae b (Hib) conjugate vaccine in a rat model.

    PubMed

    Mawas, Fatme; Dickinson, Robert; Douglas-Bardsley, Alexandra; Xing, Dorothy K L; Sesardic, Dorothea; Corbel, Michael J

    2006-04-24

    We have previously shown that, consistent with clinical trial results, the immune response to a Haemophilus influenzae b (Hib) conjugate vaccine in a rat model was compromised and modulated when given combined with a DTaP3 vaccine, as compared to both vaccines given separately. The present study extended our investigation to evaluate the immunogenicity of all DTaP3 components in combined versus separate administration of Hib with DTaP3 and investigated immune interactions between Hib and individual components of DTaP3. Rats were immunised with Hib and DTaP3 or with Hib and individual DTaP3 components. Cellular and humoral immune responses to Hib and DTaP3 components were evaluated. Our results indicate that the immunogenicity of DTaP3 components was similar or greater in combined versus separate administration of Hib and DTaP3. Moreover, combined administration of Hib and TT reduced immunogenicity of both Hib and TT. Hib immunogenicity was also significantly reduced when given combined with FHA and following adsorption to Al(OH)3.

  4. Antibiotic non-susceptibility among Streptococcus pneumoniae and Haemophilus influenzae isolates identified in African cohorts: a meta-analysis of three decades of published studies.

    PubMed

    Ginsburg, Amy Sarah; Tinkham, Laura; Riley, Katherine; Kay, Noa A; Klugman, Keith P; Gill, Christopher J

    2013-12-01

    Management of community-acquired pneumonia caused by Streptococcus pneumoniae and Haemophilus influenzae type B (Hib) can be complicated by emerging antimicrobial non-susceptibility. We conducted a meta-analysis to examine the antibiotic susceptibility of community-acquired invasive infections with S. pneumoniae and Hib in Africa from 1978 to 2011. With the notable exceptions of widespread trimethoprim/sulfamethoxazole (SXT) and tetracycline non-susceptibility, the majority of pneumococci remain susceptible to ampicillin/amoxicillin. However, 23.8% of pneumococcal meningitis isolates are non-susceptible to penicillin. Similarly, Hib isolates show non-susceptibility to SXT, tetracycline, erythromycin and chloramphenicol. β-Lactamase production among Hib isolates is increasing, a new observation for Africa, but is mitigated somewhat by Hib vaccination scale-up. In summary, pneumococcal susceptibility to amoxicillin remains high throughout Africa, and amoxicillin can be effectively and safely used as first-line treatment for childhood pneumonia. Data support first-line treatment of bacterial meningitis with ceftriaxone or cefotaxime. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  5. Immunogenicity and safety of measles-mumps-rubella and varicella vaccines coadministered with a fourth dose of Haemophilus influenzae type b and Neisseria meningitidis serogroups C and Y-tetanus toxoid conjugate vaccine in toddlers: a pooled analysis of randomized trials.

    PubMed

    Bryant, Kristina; McVernon, Jodie; Marchant, Colin; Nolan, Terry; Marshall, Gary; Richmond, Peter; Marshall, Helen; Nissen, Michael; Lambert, Stephen; Aris, Emmanuel; Mesaros, Narcisa; Miller, Jacqueline

    2012-08-01

    A pooled analysis was conducted of 1257 toddlers who received a fourth dose of Haemophilus influenzae type b-Neisseria meningitidis serogroups C and Y-tetanus toxoid conjugate vaccine (HibMenCY-TT) or Hib conjugate vaccine (Hib polysaccharide conjugated to N. meningitidis outer membrane protein) coadministered with measles-mumps-rubella (MMR) and varicella (VAR) vaccines (NCT00134719/NCT00289783). Noninferiority of immunological responses to MMR and VAR was demonstrated between groups and incidences of MMR- and VAR-specific solicited symptoms were similar, indicating that HibMenCY-TT can be coadministered with MMR and VAR.

  6. A glycoconjugate of Haemophilus influenzae Type b capsular polysaccharide with tetanus toxoid protein: hydrodynamic properties mainly influenced by the carbohydrate.

    PubMed

    Abdelhameed, Ali Saber; Adams, Gary G; Morris, Gordon A; Almutairi, Fahad M; Duvivier, Pierre; Conrath, Karel; Harding, Stephen E

    2016-02-26

    Three important physical properties which may affect the performance of glycoconjugate vaccines against serious disease are molar mass (molecular weight), heterogeneity (polydispersity), and conformational flexibility in solution. The dilute solution behaviour of native and activated capsular polyribosylribitol (PRP) polysaccharides extracted from Haemophilus influenzae type b (Hib), and the corresponding glycoconjugate made by conjugating this with the tetanus toxoid (TT) protein have been characterized and compared using a combination of sedimentation equilibrium and sedimentation velocity in the analytical ultracentrifuge with viscometry. The weight average molar mass of the activated material was considerably reduced (Mw ~ 0.24 × 10(6) g.mol(-1)) compared to the native (Mw ~ 1.2 × 10(6) g.mol(-1)). Conjugation with the TT protein yielded large polydisperse structures (of Mw ~ 7.4 × 10(6) g.mol(-1)), but which retained the high degree of flexibility of the native and activated polysaccharide, with frictional ratio, intrinsic viscosity, sedimentation conformation zoning behaviour and persistence length all commensurate with highly flexible coil behaviour and unlike the previously characterised tetanus toxoid protein (slightly extended and hydrodynamically compact structure with an aspect ratio of ~3). This non-protein like behaviour clearly indicates that it is the carbohydrate component which mainly influences the physical behaviour of the glycoconjugate in solution.

  7. Levels of Antibodies Specific to Tetanus Toxoid, Haemophilus influenzae Type b, and Pneumococcal Capsular Polysaccharide in Healthy Children and Adults

    PubMed Central

    Schauer, Uwe; Stemberg, Frank; Rieger, Christian H. L.; Büttner, Wolfgang; Borte, Michael; Schubert, Simone; Möllers, Helga; Riedel, Frank; Herz, Udo; Renz, Harald; Herzog, Wilhelm

    2003-01-01

    Antibody levels specific for capsular polysaccharides of Streptococcus pneumoniae and Haemophilus influenzae type b (Hib) and for tetanus toxoid were measured in serum samples of 386 age-stratified subjects. The study group consists of healthy adult blood donors and hospitalized children undergoing elective surgery, excluding individuals with a history of infection. In children, anti-tetanus toxoid antibody levels displayed two peaks of 1.20 IU/ml (20.4 mg/liter) and 1.65 IU/ml (28.1 mg/liter) related to the schedule of routine childhood immunization in the first year and at 8 years of age. Eighty percent of the antibodies are of the immunoglobulin G1 (IgG1) isotype. For pneumococcal capsular polysaccharide (PCP), the specific antibody levels represent the acquisition of natural immunity. The initial concentration of 9.2 mg/liter was low in infancy (0.5 to 1 years of age) and remained low until 3 to 4 years of age (14.6 mg/liter). During this period PCP antibodies were almost 100% of the IgG2 subclass. Thereafter, IgG anti-PCP antibody titers increased steadily to adult levels (59.5 mg/liter). The data are intended to provide reference ranges to aid in the interpretation of specific antibody determinations in the clinical setting. PMID:12626443

  8. Patterns of binding of aluminum-containing adjuvants to Haemophilus influenzae type b and meningococcal group C conjugate vaccines and components

    PubMed Central

    Otto, Robert B.D.; Burkin, Karena; Amir, Saba Erum; Crane, Dennis T.; Bolgiano, Barbara

    2015-01-01

    The basis of Haemophilus influenzae type b (Hib) and Neisseria meningitidis serogroup C (MenC) glycoconjugates binding to aluminum-containing adjuvants was studied. By measuring the amount of polysaccharide and protein in the non-adsorbed supernatant, the adjuvant, aluminum phosphate, AlPO4, was found to be less efficient than aluminum hydroxide, Al(OH)3 at binding to the conjugates, at concentrations relevant to licensed vaccine formulations and when equimolar. At neutral pH, binding of TT conjugates to AlPO4 was facilitated through the carrier protein, with only weak binding of AlPO4 to CRM197 being observed. There was slightly higher binding of either adjuvant to tetanus toxoid conjugates, than to CRM197 conjugates. This was verified in AlPO4 formulations containing DTwP–Hib, where the adsorption of TT-conjugated Hib was higher than CRM197-conjugated Hib. At neutral pH, the anionic Hib and MenC polysaccharides did not appreciably bind to AlPO4, but did bind to Al(OH)3, due to electrostatic interactions. Phosphate ions reduced the binding of the conjugates to the adjuvants. These patterns of adjuvant adsorption can form the basis for future formulation studies with individual and combination vaccines containing saccharide-protein conjugates. PMID:26194164

  9. Diagnosis of Streptococcus pneumoniae and Haemophilus influenzae type b meningitis by identifying DNA from cerebrospinal fluid-impregnated filter paper strips.

    PubMed

    Peltola, Heikki; Roine, Irmeli; Leinonen, Maija; Kuisma, Leena; Mata, Antonio González; Arbo, Antonio; Goyo, José; Saukkoriipi, Annika

    2010-02-01

    Bacterial meningitis remains often etiologically unconfirmed, especially in resource-poor settings. We tested the potential of real-time polymerase chain reaction to identify Streptococcus pneumoniae (Pnc) and Haemophilus influenzae type b (Hib) from cerebrospinal fluid impregnated on filter paper strips. Pnc and Hib genome equivalents were blindly quantified by polymerase chain reaction from 129 liquid cerebrospinal fluid (CSF) samples-the standard-and strips stored at room temperature for months. Genome counts were compared by simple regression. The strips showed a sensitivity and specificity of 92% and 99% for Pnc, and of 70% and 100% for Hib, respectively. The positive and negative predictive values were 94% and 97% for Pnc, and 100% and 89% for Hib, respectively. For Pnc, the positive and negative likelihood ratio was 92 and 0.08, and the overall accuracy 98%, whereas for Hib they were 70 and 0.30, and 91%, respectively. Genome counting showed good correlation between the filter paper and liquid CSF samples, r(2) being 0.87 for Pnc and 0.68 for Hib (P < 0.0001 for both). Although not replacing bacterial culture, filter paper strips offer an easy way to collect and store CSF samples for later bacteriology. They can also be transported in standard envelops by regular mail.

  10. Evaluation of ceftobiprole activity against a variety of gram-negative pathogens, including Escherichia coli, Haemophilus influenzae (β-lactamase positive and β-lactamase negative), and Klebsiella pneumoniae, in a rabbit meningitis model.

    PubMed

    Stucki, A; Cottagnoud, M; Acosta, F; Egerman, U; Läuffer, J; Cottagnoud, P

    2012-02-01

    Ceftobiprole medocaril, a new cephalosporin, is highly active against a broad spectrum of Gram-positive and Gram-negative clinical pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant pneumococci. In this study, we tested ceftobiprole against various Gram-negative pathogens in a rabbit meningitis model and determined its penetration into the cerebrospinal fluid (CSF). In this animal model, ceftobiprole produced an antibacterial activity similar to that of cefepime against an Escherichia coli strain, a Klebsiella pneumoniae strain, and a β-lactamase-negative Haemophilus influenzae strain. Against a β-lactamase-positive H. influenzae strain, ceftobiprole was significantly superior. The penetration of ceftobiprole through inflamed meninges reached about 16% of serum levels compared to about 2% of serum levels through uninflamed meninges.

  11. Evaluation of Ceftobiprole Activity against a Variety of Gram-Negative Pathogens, Including Escherichia coli, Haemophilus influenzae (β-Lactamase Positive and β-Lactamase Negative), and Klebsiella pneumoniae, in a Rabbit Meningitis Model

    PubMed Central

    Stucki, A.; Cottagnoud, M.; Acosta, F.; Egerman, U.; Läuffer, J.

    2012-01-01

    Ceftobiprole medocaril, a new cephalosporin, is highly active against a broad spectrum of Gram-positive and Gram-negative clinical pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant pneumococci. In this study, we tested ceftobiprole against various Gram-negative pathogens in a rabbit meningitis model and determined its penetration into the cerebrospinal fluid (CSF). In this animal model, ceftobiprole produced an antibacterial activity similar to that of cefepime against an Escherichia coli strain, a Klebsiella pneumoniae strain, and a β-lactamase-negative Haemophilus influenzae strain. Against a β-lactamase-positive H. influenzae strain, ceftobiprole was significantly superior. The penetration of ceftobiprole through inflamed meninges reached about 16% of serum levels compared to about 2% of serum levels through uninflamed meninges. PMID:22064544

  12. 67 FR 64386 - Enhancement of Surveillance for Trimethoprim-Sulfamethoxazole Resistant Invasive Respiratory and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2002-10-18

    ... cerebrospinal fluid infections caused by key Pathogens-Streptococcus Pneumoniae, Haemophilus Influenzae, and non... pathogens causing meningitis (pneumococcus, Haemophilus Influenzae, and Meningococcus). The infrastructure... testing, for meningitis agents including pneumococcus and Haemophilus Influenzae. Laboratory staff have...

  13. Virulence and Draft Genome Sequence Overview of Multiple Strains of the Swine Pathogen Haemophilus parasuis

    PubMed Central

    Brockmeier, Susan L.; Register, Karen B.; Kuehn, Joanna S.; Nicholson, Tracy L.; Loving, Crystal L.; Bayles, Darrell O.; Shore, Sarah M.; Phillips, Gregory J.

    2014-01-01

    Haemophilus parasuis is the cause of Glässer's disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. Investigation of this animal disease is complicated by the enormous differences in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to subclinical carriage. To identify differences in genotype that could account for virulence phenotypes, we established the virulence of, and performed whole genome sequence analysis on, 11 H. parasuis strains. Virulence was assessed by evaluating morbidity and mortality following intranasal challenge of Caesarean-derived, colostrum-deprived (CDCD) pigs. Genomic DNA from strains Nagasaki (serotype 5), 12939 (serotype 1), SW140 (serotype 2), 29755 (serotype 5), MN-H (serotype 13), 84-15995 (serotype 15), SW114 (serotype 3), H465 (serotype 11), D74 (serotype 9), and 174 (serotype 7) was used to generate Illumina paired-end libraries for genomic sequencing and de novo assembly. H. parasuis strains Nagasaki, 12939, SH0165 (serotype 5), SW140, 29755, and MN-H exhibited a high level of virulence. Despite minor differences in expression of disease among these groups, all pigs challenged with these strains developed clinical signs consistent with Glässer's disease between 1–7 days post-challenge. H. parasuis strains 84-15995 and SW114 were moderately virulent, in that approximately half of the pigs infected with each developed Glässer's disease. H. parasuis strains H465, D74, and 174 were minimally virulent or avirulent in the CDCD pig model. Comparative genomic analysis among strains identified several noteworthy differences in coding regions. These coding regions include predicted outer membrane, metabolism, and pilin or adhesin related genes, some of which likely contributed to the differences in virulence and systemic disease observed following challenge. These data will be useful for identifying H. parasuis virulence factors and

  14. Virulence and draft genome sequence overview of multiple strains of the swine pathogen Haemophilus parasuis.

    PubMed

    Brockmeier, Susan L; Register, Karen B; Kuehn, Joanna S; Nicholson, Tracy L; Loving, Crystal L; Bayles, Darrell O; Shore, Sarah M; Phillips, Gregory J

    2014-01-01

    Haemophilus parasuis is the cause of Glässer's disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. Investigation of this animal disease is complicated by the enormous differences in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to subclinical carriage. To identify differences in genotype that could account for virulence phenotypes, we established the virulence of, and performed whole genome sequence analysis on, 11 H. parasuis strains. Virulence was assessed by evaluating morbidity and mortality following intranasal challenge of Caesarean-derived, colostrum-deprived (CDCD) pigs. Genomic DNA from strains Nagasaki (serotype 5), 12939 (serotype 1), SW140 (serotype 2), 29755 (serotype 5), MN-H (serotype 13), 84-15995 (serotype 15), SW114 (serotype 3), H465 (serotype 11), D74 (serotype 9), and 174 (serotype 7) was used to generate Illumina paired-end libraries for genomic sequencing and de novo assembly. H. parasuis strains Nagasaki, 12939, SH0165 (serotype 5), SW140, 29755, and MN-H exhibited a high level of virulence. Despite minor differences in expression of disease among these groups, all pigs challenged with these strains developed clinical signs consistent with Glässer's disease between 1-7 days post-challenge. H. parasuis strains 84-15995 and SW114 were moderately virulent, in that approximately half of the pigs infected with each developed Glässer's disease. H. parasuis strains H465, D74, and 174 were minimally virulent or avirulent in the CDCD pig model. Comparative genomic analysis among strains identified several noteworthy differences in coding regions. These coding regions include predicted outer membrane, metabolism, and pilin or adhesin related genes, some of which likely contributed to the differences in virulence and systemic disease observed following challenge. These data will be useful for identifying H. parasuis virulence factors and

  15. Protective Efficacy of an Inactive Vaccine Based on the LY02 Isolate against Acute Haemophilus parasuis Infection in Piglets.

    PubMed

    Li, Xiao-Hua; Zhao, Guo-Zhen; Qiu, Long-Xin; Dai, Ai-Ling; Wu, Wang-Wei; Yang, Xiao-Yan

    2015-01-01

    Haemophilus parasuis can cause Glässer's disease characterized by fibrinous polyserositis, polyarthritis, and meningitis. The current prevention of Glässer's disease is mainly based on the inactive vaccines; however, the protective efficacy usually fails in heterogeneous or homologous challenges. Here, the predominant lineage of H. parasuis (LY02 strain) in Fujian province, China, characterized as serovar 5, was used to evaluate the protective immunity against acute H. parasuis infection in piglets after inactivation. Following challenging with H. parasuis, only mild lesions in the pigs immunized with the killed vaccine were observed, whereas the typical symptoms of Glässer's disease presented in the nonimmunized piglets. A strong IgG immune response was induced by the inactive vaccine. CD4(+) and CD8(+) T lymphocyte levels were increased, indicating the potent cellular immune responses were elicited. The significantly high levels of IL-2, IL-4, TGF-β, and IFN-γ in sera from pigs immunized with this killed vaccine suggested that the mixed Th1 and Th2 immune responses were induced, associated with the high protection against H. parasuis infection compared to the nonimmunized animals. This study indicated that the inactivated LY02 strain of H. parasuis could serve as a potential vaccine candidate to prevent the prevalence of H. parasuis in Fujian province, China.

  16. Hib Photos

    MedlinePlus

    ... fluid culture positive for Haemophilus influenzae , type b (Gram stain) www.vaccineinformation.org/photos/hib_aap001.jpg Copyright American Academy of Pediatrics Haemophilus influenzae type b. ... gram-negative Haemophilus influenzae bacteria www.vaccineinformation.org/photos/ ...

  17. Evaluation of the effectiveness of Haemophilus influenzae type b conjugate vaccine introduction against radiologically-confirmed hospitalized pneumonia in young children in Ukraine.

    PubMed

    Pilishvili, Tamara; Chernyshova, Liudmyla; Bondarenko, Anastasia; Lapiy, Fedir; Sychova, Irina; Cohen, Adam; Flannery, Brendan; Hajjeh, Rana

    2013-07-01

    Haemophilus influenzae type b (Hib) conjugate vaccine was included into the national vaccination schedule of Ukraine in 2006. The objective of this study was to demonstrate the effectiveness of Hib conjugate vaccine against radiologically-confirmed hospitalized pneumonia in children. Children <2 years old with radiologically confirmed pneumonia admitted to 11 participating hospitals in Kiev and Dnepropetrovsk between April 2007 and June 2009 were included in a case-control evaluation. Four controls were matched to each case by date of birth (within 14 days) and outpatient clinic. We estimated ORs for vaccination and vaccine effectiveness ((1 - OR)*100%) using conditional logistic regression, adjusting for comorbid conditions and contraindications for vaccination. We enrolled 188 case-children and 735 controls. Median age was 16 months (range 4-24 months). Fifty-one percent of cases and 67% of controls received ≥1 doses of Hib conjugate vaccine; 26% of cases and 37% of controls received ≥3 doses. The effectiveness of ≥1 dose Hib conjugate vaccine was estimated at 45% (95% CI 18%-63%). Our study showed that Hib infections are important causes of hospitalized radiologically confirmed pneumonia in young children in Ukraine. Copyright © 2013. Published by Mosby, Inc.

  18. Characterization of Encapsulated and Noncapsulated Haemophilus influenzae and Determination of Phylogenetic Relationships by Multilocus Sequence Typing

    PubMed Central

    Meats, Emma; Feil, Edward J.; Stringer, Suzanna; Cody, Alison J.; Goldstein, Richard; Kroll, J. Simon; Popovic, Tanja; Spratt, Brian G.

    2003-01-01

    A multilocus sequence typing (MLST) scheme has been developed for the unambiguous characterization of encapsulated and noncapsulated Haemophilus influenzae isolates. The sequences of internal fragments of seven housekeeping genes were determined for 131 isolates, comprising a diverse set of 104 serotype a, b, c, d, e, and f isolates and 27 noncapsulated isolates. Many of the encapsulated isolates had previously been characterized by multilocus enzyme electrophoresis (MLEE), and the validity of the MLST scheme was established by the very similar clustering of isolates obtained by these methods. Isolates of serotypes c, d, e, and f formed monophyletic groups on a dendrogram constructed from the differences in the allelic profiles of the isolates, whereas there were highly divergent lineages of both serotype a and b isolates. Noncapsulated isolates were distinct from encapsulated isolates and, with one exception, were within two highly divergent clusters. The relationships between the major lineages of encapsulated H. influenzae inferred from MLEE data could not be discerned on a dendrogram constructed from differences in the allelic profiles, but were apparent on a tree reconstructed from the concatenated nucleotide sequences. Recombination has not therefore completely eliminated phylogenetic signal, and in support of this, for encapsulated isolates, there was significant congruence between many of the trees reconstructed from the sequences of the seven individual loci. Congruence was less apparent for noncapsulated isolates, suggesting that the impact of recombination is greater among noncapsulated than encapsulated isolates. The H. influenzae MLST scheme is available at www.mlst.net, it allows any isolate to be compared with those in the MLST database, and (for encapsulated isolates) it assigns isolates to their phylogenetic lineage, via the Internet. PMID:12682154

  19. Detection of Haemophilus parasuis isolates from South China by loop-mediated isothermal amplification and isolate characterisation.

    PubMed

    Zhang, Jian-Min; Shen, Hai-Yan; Liao, Ming; Ren, Tao; Guo, Li-Li; Xu, Cheng-Gang; Feng, Sai-Xiang; Fan, Hui-Ying; Li, Jing-Yi; Chen, Ji-Dang; Zhang, Bin

    2012-04-24

    Haemophilus parasuis is the etiological agent of Glässer's disease, which is characterised by fibrinous polyserositis, meningitis and polyarthritis, causing severe economic losses to the swine industry. In this study, a loop-mediated isothermal amplification (LAMP) test was developed to improve the specificity, facility and speed of diagnosis of H. parasuis isolates. The LAMP assay rapidly amplified the target gene within 50 min incubation at 63 °C in a laboratory water bath. The LAMP amplicon could be visualised directly in the reaction tubes following the addition of SYBR Green I dye. The detection limit of this LAMP method was 10 CFU/mL, which was 10 times more sensitive than the earlier 16S rRNA polymerase chain reaction (PCR) test conducted by Oliveira, Galina and Pijoan (2001), and no cross-reactivity was observed from other non-H. parasuis strains. This LAMP test was evaluated further on 187 clinical specimens from pigs suspected of being infected with H. parasuis. Forty-three were found positive by bacterial isolation of H. parasuis, as well as by the 16S rRNA PCR and LAMP tests. The 43 H. parasuis isolates were classified into 9 serovars and had 37 genetic patterns when analysed by pulsed-field gel electrophoresis (PFGE). This displayed that various H. parasuis serovars and genotypes were widely distributed in South China. Therefore, the speed, specificity and sensitivity of the LAMP test, the lack of a need for expensive equipment, and the visual readout showed great potential for a correct clinical diagnosis of H. parasuis in favour of controlling Glässer's disease.

  20. Transformed Recombinant Enrichment Profiling Rapidly Identifies HMW1 as an Intracellular Invasion Locus in Haemophilus influenza.

    PubMed

    Mell, Joshua Chang; Viadas, Cristina; Moleres, Javier; Sinha, Sunita; Fernández-Calvet, Ariadna; Porsch, Eric A; St Geme, Joseph W; Nislow, Corey; Redfield, Rosemary J; Garmendia, Junkal

    2016-04-01

    Many bacterial species actively take up and recombine homologous DNA into their genomes, called natural competence, a trait that offers a means to identify the genetic basis of naturally occurring phenotypic variation. Here, we describe "transformed recombinant enrichment profiling" (TREP), in which natural transformation is used to generate complex pools of recombinants, phenotypic selection is used to enrich for specific recombinants, and deep sequencing is used to survey for the genetic variation responsible. We applied TREP to investigate the genetic architecture of intracellular invasion by the human pathogen Haemophilus influenzae, a trait implicated in persistence during chronic infection. TREP identified the HMW1 adhesin as a crucial factor. Natural transformation of the hmw1 operon from a clinical isolate (86-028NP) into a laboratory isolate that lacks it (Rd KW20) resulted in ~1,000-fold increased invasion into airway epithelial cells. When a distinct recipient (Hi375, already possessing hmw1 and its paralog hmw2) was transformed by the same donor, allelic replacement of hmw2AHi375 by hmw1A86-028NP resulted in a ~100-fold increased intracellular invasion rate. The specific role of hmw1A86-028NP was confirmed by mutant and western blot analyses. Bacterial self-aggregation and adherence to airway cells were also increased in recombinants, suggesting that the high invasiveness induced by hmw1A86-028NP might be a consequence of these phenotypes. However, immunofluorescence results found that intracellular hmw1A86-028NP bacteria likely invaded as groups, instead of as individual bacterial cells, indicating an emergent invasion-specific consequence of hmw1A-mediated self-aggregation.

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