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Sample records for haemophilus influenzae strain

  1. Draft Genome Sequences of Eight Nontypeable Haemophilus influenzae Strains Previously Characterized Using an Electrophoretic Typing Scheme.

    Science.gov (United States)

    Mussa, Huda J; VanWagoner, Timothy M; Morton, Daniel J; Seale, Thomas W; Whitby, Paul W; Stull, Terrence L

    2015-11-25

    Nontypeable Haemophilus influenzae is an important cause of human disease. Strains were selected for genome sequencing to represent the breadth of nontypeable strains within the species, as previously defined by the electrophoretic mobility of 16 metabolic enzymes.

  2. Differentiation of Haemophilus aegyptius and Haemophilus influenzae.

    Science.gov (United States)

    Mazloum, H A; Kilian, M; Mohamed, Z M; Said, M D

    1982-04-01

    This study aimed at clarifying the relationship of Haemophilus aegyptius and Haemophilus influenzae isolated from acute conjunctivitis in Egypt. Twenty-nine freshly isolated strains selected from a large clinical material were examined for morphological and growth characteristics, biochemical properties and susceptibility to selected antibiotics. H. aegyptius strains were clearly differentiated from strains of H. influenzae by their inability to grow on tryptic soy agar containing X + V factors, by their susceptibility to trooleandomycin, by a distinct bacillary morphology, and, in part, by not fermenting xylose. The results confirm that H. aegyptius is distinct from H. influenzae and provides reproducible means of differentiating the two species.

  3. About Haemophilus influenzae Disease

    Science.gov (United States)

    ... Hib Vaccination Hib Vaccination Meningitis Pneumonia Sepsis About Haemophilus influenzae Disease Recommend on Facebook Tweet Share Compartir H. ... severe, such as a bloodstream infection. Types of Haemophilus influenzae Infections Infections caused by these bacteria... Causes, How ...

  4. Surface structures and adherence properties of diverse strains of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    St Geme, J W; Gilsdorf, J R; Falkow, S

    1991-10-01

    Haemophilus influenzae biogroup aegyptius is an important cause of conjunctivitis and has recently been associated with Brazilian purpuric fever (BPF), a fulminant systemic disease of children. To gain insight into the bacterial factors involved in the pathogenesis of this disease, we investigated the surface structures and adherence properties of eight different strains of H. influenzae biogroup aegyptius, including both BPF and non-BPF isolates. All eight strains were able to express long peritrichous pili similar to those observed in H. influenzae. As in H. influenzae, piliation correlated with colony binding of human erythrocytes. However, two strains were capable of hemagglutination in the absence of pili; in these strains, hemagglutination was insensitive to protease treatment, suggesting a nonproteinaceous hemagglutinin. All strains possessed short, thin, surface fibers distinct from long pili and demonstrated efficient attachment to cultured human conjunctival cells. Attachment to conjunctival cells occurred independently of long pili or a capacity for hemagglutination.

  5. Draft Genome Sequences of Six Nontypeable Haemophilus influenzae Strains That Establish Bacteremia in the Infant Rat Model of Invasive Disease

    Science.gov (United States)

    VanWagoner, Timothy M.; Seale, Thomas W.; Mussa, Huda J.; Cole, Brett K.; Whitby, Paul W.; Stull, Terrence L.

    2015-01-01

    Haemophilus influenzae is an important cause of invasive disease. The infant rat is the accepted model of invasive H. influenzae disease. Here, we report the genome sequences of six nontypeable H. influenzae strains that establish bacteremia in the infant rat. PMID:26404588

  6. Occurrence of Haemophilus influenzae strains in three Brazilian states since the introduction of a conjugate Haemophilus influenzae type b vaccine

    Directory of Open Access Journals (Sweden)

    A.E.C.C. de Almeida

    2005-05-01

    Full Text Available Few vaccines in history have induced such a dramatic decline in incidence over such a short period of time as the Haemophilus influenzae type b (Hib conjugate. This vaccine was introduced in 1988 in the United States, but only in 1999 was Hib immunization introduced by the Brazilian Ministry of Health as part of the routine infant National Immunization Program. The authors analyzed 229 H. influenzae (Hi isolates from Public Health Laboratories in three Brazilian states: Pernambuco (Northeast, N = 54, Santa Catarina (South, N = 19, and Rio de Janeiro (Southeast, N = 156. The isolates were collected from Brazilian children 0-10 years of age with meningitis and other infections from 1990 to 2003 and were part of the research collection of the National Institute of Quality Control in Health, FIOCRUZ. Bacterial strains were characterized by serotyping and biotyping. During the pre-vaccination period the prevalence infection due to Hib was of 165 isolates and only 2 non-b Hi among all the notified meningitis infections caused by Hi. Our results showed a significant decrease in the prevalence of Hib meningitis from 165 to 33 isolates after 1999. However, during the post-vaccination period of 2001-2003 we observed an increase in the number of non-b Hi isolates: only 2 non-b strains isolated from 1990 to 1999 and 29 from 1999 to 2003. Based on the present data, the authors emphasize the need for more sensitive epidemiological and bacteriological studies aiming the improvement of the available Hib vaccine, in order to protect the susceptible population to infections due to other serological types of Hi and the reevaluation of immunization schedules used by the National Immunization Program.

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

    Science.gov (United States)

    de Gier, Camilla; Pickering, Janessa L; Richmond, Peter C; Thornton, Ruth B; Kirkham, Lea-Ann S

    2016-09-01

    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).

  8. Complete genome sequence of Haemophilus somnus (Histophilus somni) strain 129Pt and comparison to Haemophilus ducreyi 35000HP and Haemophilus influenzae Rd.

    Science.gov (United States)

    Challacombe, Jean F; Duncan, A J; Brettin, Thomas S; Bruce, David; Chertkov, Olga; Detter, J Chris; Han, Cliff S; Misra, Monica; Richardson, Paul; Tapia, Roxanne; Thayer, Nina; Xie, Gary; Inzana, Thomas J

    2007-03-01

    Haemophilus somnus can be either a commensal of bovine mucosal surfaces or an opportunistic pathogen. Pathogenic strains of H. somnus are a significant cause of systemic disease in cattle. We report the genome sequence of H. somnus 129Pt, a nonpathogenic commensal preputial isolate, and the results of a genome-wide comparative analysis of H. somnus 129Pt, Haemophilus influenzae Rd, and Haemophilus ducreyi 35000HP. We found unique genes in H. somnus 129Pt involved in lipooligosaccharide biosynthesis, carbohydrate uptake and metabolism, cation transport, amino acid metabolism, ubiquinone and menaquinone biosynthesis, cell surface adhesion, biosynthesis of cofactors, energy metabolism, and electron transport. There were also many genes in common among the three organisms. Our comparative analyses of H. somnus 129Pt, H. influenzae Rd, and H. ducreyi 35000HP revealed similarities and differences in the numbers and compositions of genes involved in metabolism, host colonization, and persistence. These results lay a foundation for research on the host specificities and niche preferences of these organisms. Future comparisons between H. somnus 129Pt and virulent strains will aid in the development of protective strategies and vaccines to protect cattle against H. somnus disease.

  9. Stable, conserved outer membrane epitope of strains of Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever.

    OpenAIRE

    Lesse, A J; Gheesling, L L; Bittner, W E; Myers, S.D.; Carlone, G M

    1992-01-01

    Brazilian purpuric fever is a rapidly fatal childhood disease associated with a clonal strain of Haemophilus influenzae biogroup aegyptius. We describe a conserved, surface-exposed epitope present on 95% of H. influenzae biogroup aegyptius isolates that are associated with Brazilian purpuric fever. This epitope, defined by reaction with the monoclonal antibody 8G3, is on or associated with the 48-kDa heat-modifiable P1 protein. The epitope is absent on strains of H. influenzae biogroup aegypt...

  10. Brazilian purpuric fever: evolutionary genetic relationships of the case clone of Haemophilus influenzae biogroup aegyptius to encapsulated strains of Haemophilus influenzae.

    Science.gov (United States)

    Musser, J M; Selander, R K

    1990-01-01

    As a first step toward identifying the evolutionary origin of a pathogenic clone of Haemophilus influenzae biogroup aegyptius causing Brazilian purpuric fever, chromosomal variation and genetic relationships were indexed among 17 isolates of biogroup aegyptius and 2209 previously characterized encapsulated H. influenzae strains recovered from 30 countries on six continents. Biogroup aegyptius isolates form three distinct evolutionary lineages of the species H. influenzae and isolates of the case clone are genetically not closely related to other isolates classified as biogroup aegyptius. The Brazilian purpuric fever case clone was found to be genetically allied with H. influenzae isolates producing serotype c polysaccharide capsule. The population genetic evidence suggests that biogroup aegyptius isolates may represent cell lineages occasionally transmitted from nonhuman hosts or spawned from a much larger base population consisting of genetically diverse nonpathogenic precursor clones.

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

    Science.gov (United States)

    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

    1988-08-01

    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.

  12. Variable number of tandem repeats in clinical strains of Haemophilus influenzae

    NARCIS (Netherlands)

    A.F. van Belkum (Alex); S. Scherer; D. Willemse; L. van Alphen (Loek); H.A. Verbrugh (Henri); W.B. van Leeuwen (Willem)

    1997-01-01

    textabstractAn algorithm capable of identifying short repeat motifs was developed and used to screen the whole genome sequence available for Haemophilus influenzae, since some of these repeats have been shown to affect bacterial virulence. Various di- to hexanucleotide

  13. Genotyping of Haemophilus influenzae type b strains and their incidence in the clinical samples isolated from Iranian patients

    Science.gov (United States)

    Bagherzadeh Khodashahri, Somayeh; Siadat, Seyed Davar; Rahbar, Mohammad; Abdollahpour-Alitappeh, Meghdad; Vaziri, Farzam; Rahnamaye-Farzami, Mrjan; Mohammadzadeh, Mona; Davari, Mehdi; Fateh, Abolfazl; Masoumi, Morteza

    2015-01-01

    Background and Objective: Haemophilus influenzae type b (Hib) is divided into two distinct genotypes, type I and type II, based on the structure of capsular polysaccharides. The capsulation locus of Haemophilus influenzae type b consists of three functionally distinct regions, designated regions 1 to 3. Region III contains hcsA and hcsB genes; however, notable sequence variation in this region can be used to recognize different Hib genotypes. The purpose of this study was to investigate the prevalence and genotype of the Hib strains isolated from patients with invasive disease in Iran. Materials and Methods: In the present study, 8 pairs of primers were used for identification and serotyping of encapsulated Haemophilus influenzae strains, as well as confirmation of species identification. Additionally, in order to identify the capsular genotypes of Haemophilus influenzae type b (type I and II), two additional primer pairs were used to amplify the hcsA gene. Results: Out of 50 isolates of H. influenzae, four were found to be type b. Interestingly, among these 4 Hib isolates, 2 strains belonged to the type-II category. Conclusion: Our study shows that the prevalence of both Hib types I and II seems to be high in Iran. PMID:26668700

  14. Brazilian purpuric fever caused by Haemophilus influenzae biogroup aegyptius strains lacking the 3031 plasmid.

    Science.gov (United States)

    Tondella, M L; Quinn, F D; Perkins, B A

    1995-01-01

    Brazilian purpuric fever (BPF) is a life-threatening pediatric infection caused by Haemophilus influenzae biogroup aegyptius (Hae), an organism formerly associated with only self-limited purulent conjunctivitis. Strains of Hae causing BPF have a 24-MDa plasmid with a specific AccI restriction pattern designated 3031. This plasmid was thought to code for a virulence factor because it had been detected only among Hae strains isolated from BPF cases or their contacts. From 3 typical BPF cases recently identified in São Paulo State, sterile-site Hae isolates were obtained; these isolates were similar to earlier BPF-associated Hae except they did not possess a 3031 plasmid. HindIII restricted chromosomal DNA from these strains was probed with purified 3031 plasmid DNA under high-stringency conditions. There was no evidence that 3031 plasmid DNA had become chromosomally integrated. It appears that the 3031 plasmid does not code for BPF-specific virulence factors.

  15. Carcinoembryonic antigens are targeted by diverse strains of typable and non-typable Haemophilus influenzae.

    Science.gov (United States)

    Virji, M; Evans, D; Griffith, J; Hill, D; Serino, L; Hadfield, A; Watt, S M

    2000-05-01

    Haemophilus influenzae (Hi), a commensal of the human respiratory mucosa, is an important cause of localized and systemic infections. We show that distinct strains belonging to typable (THi) and non-typable (NTHi) H. influenzae target human carcinoembryonic antigens (the membrane associated CEA family of cell adhesion molecules, are now termed CEACAMs). All strains of H. influenzae biogroup aegyptius (Hi-aeg) and more than 70% of THi and NTHi strains tested specifically recognize CEACAMI-Fc soluble constructs. Furthermore, transfection of Chinese hamster ovary cells with human CEACAM1 cDNA alone was sufficient for promoting Hi interactions with the transfected cells. The majority of the Hi-aeg strains tested interacted with soluble constructs containing only the N-terminal domain. In contrast, several THi and NTHi strains reacted with soluble constructs only when additional extracellular A and B domains of the receptor were present. The use of monoclonal antibodies confirmed that THi and NTHi strains also interact primarily at the N-domain. We used site-directed mutants of CEACAM1 that contained substitutions at surface exposed amino acids and a molecular model of the N-domain to identify the residues involved in interactions with Hi ligands. The studies show that a common region exposed at the CFG face of the molecule is targeted by diverse Hi strains. However, mutation at distinct sites within this area affected the interactions of distinct strains signifying the potential for tissue tropism via this receptor. Analyses of the molecular basis of interaction with human cell lines and purified CEA show that Hi strains, especially those belonging to Hi-aeg, interact with multiple CEACAMs. Because Neisseria meningitidis (Nm) strains are also known to bind at the CFG face of the receptor, we used Nm and Hi strains in co-infection experiments and demonstrate competition between these mucosal pathogens in colonization of target cells via CEACAMs.

  16. Stable, conserved outer membrane epitope of strains of Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever.

    Science.gov (United States)

    Lesse, A J; Gheesling, L L; Bittner, W E; Myers, S D; Carlone, G M

    1992-04-01

    Brazilian purpuric fever is a rapidly fatal childhood disease associated with a clonal strain of Haemophilus influenzae biogroup aegyptius. We describe a conserved, surface-exposed epitope present on 95% of H. influenzae biogroup aegyptius isolates that are associated with Brazilian purpuric fever. This epitope, defined by reaction with the monoclonal antibody 8G3, is on or associated with the 48-kDa heat-modifiable P1 protein. The epitope is absent on strains of H. influenzae biogroup aegyptius that are not associated with Brazilian purpuric fever but is present on one strain of H. influenzae biotype II. None of 81 other Haemophilus strains tested reacted with 8G3. The sensitivity and specificity of the 8G3 monoclonal antibody in detecting Brazilian case-clone strains of H. influenzae biogroup aegyptius associated with Brazilian purpuric fever are 95 and 99%, respectively. Immunoelectron microscopy revealed that the epitope is surface exposed, and N-terminal amino acid sequencing of an 8G3-reactive P1 protein from a strain of H. influenzae biogroup aegyptius showed 100% correlation with the published N-terminal amino acid sequence of a P1 protein of H. influenzae type b. The virulence of the organism in an infant rat model of bacteremia was not dependent on the expression of this epitope.

  17. Invasive Disease Caused by Nontypeable Haemophilus influenzae

    Science.gov (United States)

    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. Clarithromycin Resistance Mechanisms of Epidemic β-Lactamase-Nonproducing Ampicillin-Resistant Haemophilus influenzae Strains in Japan.

    Science.gov (United States)

    Seyama, Shoji; Wajima, Takeaki; Nakaminami, Hidemasa; Noguchi, Norihisa

    2016-05-01

    The aim of this study was to clarify the clarithromycin resistance mechanisms of β-lactamase-nonproducing ampicillin-resistant Haemophilus influenzae strains. In all clarithromycin-resistant strains, the transcript level of acrB was significantly elevated, and these strains had a frameshift mutation in acrR Introduction of the acrR mutation into H. influenzae Rd generated a clarithromycin-resistant transformant with the same MIC as the donor strain. Our results indicate that the acrR mutation confers clarithromycin resistance by the increasing the transcription of acrB.

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

    OpenAIRE

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

  20. Carriage of antibiotic-resistant Haemophilus influenzae strains in children undergoing adenotonsillectomy.

    Science.gov (United States)

    Trafny, Elżbieta A; Olszewska-Sosińska, Olga; Antos-Bielska, Małgorzata; Kozłowska, Krystyna; Stępińska, Małgorzata; Lau-Dworak, Magdalena; Zielnik-Jurkiewicz, Beata

    2014-07-01

    Haemophilus influenzae is one of the major pathogenic bacteria in upper respiratory tract of children. In this study, the presence of various H. influenzae genotypes were followed-up for at least 13 weeks, starting from one week before surgery. Forty-one children with chronic adenoid hypertrophy were prospectively enrolled to the study. The consecutive swabs of adenoid and tonsils, two before adenotonsillectomy and two after the surgery together with homogenates of adenotonsillar tissues and lysates of the CD14(+) cells fraction were acquired from 34 children undergoing adenotonsillectomy. Up to ten isolates from each patient at each collection period were genotyped using a PFGE method and their capsular type and antibiotic susceptibility was determined. Of the 1001 isolates examined, we identified 325 isolates grouped into 16 persistent genotypes, which colonized throats for more than seven weeks and were not eliminated by the surgery. The other 506 isolates grouped into 48 transient genotypes that had been eliminated by the surgery. The resistance to ampicillin were found in 23.8% of the transient strains, and 4.7% of the newly acquired strains following the surgical intervention. In contrast, none of the persistent strains were resistant to ampicillin; however, these strains showed apparently higher level of resistance to co-trimoxazole when compared to transient strains. The transient and persistent strains did not significantly differ in bacterial viability in the biofilms formed in vitro. Some of the strains were identified in two or three different patients and were considered as the strains circulating in the region between 2010 and 2012.

  1. N-Nitrosocarbaryl-induced mutagenesis in Haemophilus influenzae strains deficient in repair and recombination.

    Science.gov (United States)

    Beattie, K L

    1975-02-01

    Mutagenesis was studied in repair- and recombination-deficient strains of Haemophilus influenzae after treatment with N-nitrosocarbaryl (NC). Three different strains of H. influenzae carrying mutations affecting excision-repair of UV-induced pyrimidine dimers exhibited normal repair of premutational lesions (as detected by decreased mutation yield resulting from post-treatment DNA synthesis delay) and normal nonreplicative mutation fixation. This indicated that neither of these phenomena are caused by the smae repair mechanism that removes UV-induced pyrimidine dimers from the DNA. The recombination-deficient mutant recI is apparently deficient in the replication-dependent mode of NC-induced mutation fixation. This conclusion is based on the following results: (I) NC-induced mutagenesis is lower in the recI strain than in rec+ cells. (2) Repair of premutational lesions (which depends on the existence of replication-dependent mutation fixation for its detection) was not detected in the recI strain. (3) When nonreplicative mutation fixation and final mutation frequency were measured in the same experiment, about I/4 to I/3 of the final mutation yield could be accounted for by nonreplicative mutation fixation in the rec+ strain, whereas all of the mutation could be accounted for in the recI strain by the nonreplicative mutation fixation. (4) When mutation fixation in strain dna9 recI was followed at the permissive (36 degrees) and nonpermissive (41 degrees) temperatures, it became apparent that in the recI strain replication-dependent mutation fixation occurs at early times, but these newly fixed mutations are unstable and disappear at later times, leaving only the mutations fixed by the nonreplicative process. The recI strain exhibits normal repair of NC-induced single-strand breaks or alkali-labile bonds in the DNA labeled before treatment, but is slow in joining discontinuties present in DNA synthesized after treatment. The results are consistent with the idea that

  2. Delineation of the species Haemophilus influenzae by phenotype, multilocus sequence phylogeny, and detection of marker genes

    DEFF Research Database (Denmark)

    Nørskov-Lauritsen, Niels; Overballe, MD; 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...

  3. Comparison of outer membrane protein and biochemical profiles of Haemophilus aegyptius and Haemophilus influenzae biotype III.

    OpenAIRE

    Carlone, G M; Sottnek, F O; Plikaytis, B. D.

    1985-01-01

    Haemophilus aegyptius and Haemophilus influenzae biotype III are morphologically and biochemically similar; however, their outer membrane protein (Sarkosyl insoluble) profiles are distinct. Of 18 strains of H. aegyptius examined, 15 had a type 1 protein profile, and 3 had a type 2 profile, whereas the 5 strains of H. influenzae biotype III examined had three other protein profile types. All Haemophilus strains examined had 31- and 76-kilodalton (kDa) proteins and minor proteins with molecular...

  4. MULTIPLE HAEMOPHILUS-INFLUENZAE STRAINS AND STRAIN VARIANTS COEXIST IN THE RESPIRATORY-TRACT OF PATIENTS WITH CYSTIC-FIBROSIS

    NARCIS (Netherlands)

    MOLLER, LVM; REGELINK, AG; GRASSELIER, H; DANKERTROELSE, JE; VANALPHEN, L

    1995-01-01

    To investigate the epidemiology of nontypeable Haemophilus influenzae in the respiratory tract of cystic fibrosis (CF) patients, H. influenzae isolates from sputum specimens of 40 CF patients were analyzed longitudinally for 2 years. The isolates were characterized by analysis of the major outer mem

  5. A novel branching pattern in the lipopolysaccharide expressed by non-typeable Haemophilus influenzae strain 1232.

    Science.gov (United States)

    Vitiazeva, Varvara; Li, Jianjun; Hood, Derek W; Moxon, E Richard; Schweda, Elke K H

    2013-08-30

    We report the novel branching pattern in lipopolysaccharide (LPS) expressed by non-typeable Haemophilus influenzae (NTHi) strain 1232. The strain expressed the β-d-Glcp-(1→4)-[α-d-Galp-(1→4)-β-d-Galp-(1→7)]-d-α-d-Hepp-(1→6)-β-d-Glcp chain linked to the proximal heptose (HepI) of the conserved triheptosyl inner-core moiety of NTHi LPS: l-α-d-HepIIIp-(1→2)-[PEtn→6]-l-α-d-HepIIp-(1→3)-l-α-d-HepIp-(1→5)-[PPEtn→4]-α-Kdop-(2→6)-lipid A. The structure has been elucidated using NMR spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and capillary electrophoresis coupled to electrospray ionization tandem mass spectrometry (CE-ESI-MS(n)) on O-deacylated LPS and core oligosaccharide (OS) materials, as well as HPLC-ESI-MS(n) on permethylated, dephosphorylated OS. It was also found that a tetrasaccharide unit bearing sialic acid [α-Neu5Ac-(2→3)-β-d-Galp-(1→4)-β-d-GlcNAcp-(1→3)-β-d-Galp-(1→] could substitute O-4 of the β-d-Glcp linked to HepI. In addition, the distal heptose (HepIII) was substituted by PCho→6-β-d-Galp-(1→ at the O-2 position.

  6. Aminoglycoside resistance in Haemophilus influenzae.

    Science.gov (United States)

    Gomez-Lus, R; Vergara, Y

    1995-04-01

    From September 1, 1990 to December 31, 1993 a total of 425 Haemophilus influenzae strains from clinical specimens were isolated in the Microbiology Laboratory of the Zaragoza University Hospital. Of these strains, 16 (33.33%) were resistant to kanamycin, neomycin, paromomycin, lividomycin and streptomycin. Demonstration of APH (3')-I activity by the phosphocellulose paper binding assay, based on the incorporation of radiolabel into lividomycin was sixfold greater than into butirosin. Two DNA probes were prepared to screen for the genes encoding APH(3') activity in kanamycin-resistant H. influenzae. Homology was observed between the aphA1 DNA probe and total cellular DNA from all 16 APH(3')-I producers. On the other hand, streptomycin-resistance was not through metabolic modification of the antibiotic.

  7. TEM-1 AND ROB-1 PRESENCE AND ANTIMICROBIAL RESISTANCE IN HAEMOPHILUS INFLUENZAE STRAINS, ISTANBUL, TURKEY.

    Science.gov (United States)

    Kuvat, Nuray; Nazik, Hasan; Berkiten, Rahmiye; Öngen, Betigül

    2015-03-01

    Resistance of 235 Haemophilus influenzae clinical isolates from Istanbul Medical Faculty Hospital, Turkey were determined against 19 antibiotics by disc diffusion method, and minimum inhibitory concentrations (MICs) of those found resistant to ampicillin, cefuroxim, chloramphenicol and meropenem were measured using E-test. Ampicillin-resistant isolates producing beta-lactamase as demonstrated by a nitrocefin assay were analyzed for the presence of TEM-1 and ROB-1 genes by PCR. Eleven percent of the isolates were resistant to ampicillin (10 µg/ml), of which 73% were beta-lactamase positive and carried TEM-1 gene, but none were positive for ROB-1 gene. All isolates susceptible to amoxicillin-clavulanate (20/10 µg/ml), azithromycin (15 µg/ml), aztreonam (30 µg/ml), cefotaxime (30 µg/ml), ceftriaxone (30 µg/ml), ciprofloxacin (5 µg/ml), levofloxacin (5 µg/ml), and telithromycin (15 µg/ml) but 24%, 15%, 4%, 4%, 2%, 1%, 1%, 0.5%, 0.5% and 0.5% were resistant to trimethoprim-sulfamethoxazole (1.25/23.75 µg/ml), tetracycline (30 µg/ml), cefaclor (30 µg/ml), clarithromycin (15 µg/ml), cefuroxime (30 µg/ml), meropenem (10 µg/ml), chloramphenicol (30 µg/ml), ampicillin-sulbactam (10/10 µg/ml), nalidixic acid (30 µg/ml), and fosfomycin (30 µg/ml), respectively. MIC values of three cefuroxime-resistant isolates was 24, 48 and > 256 µg/ml, respectively; of two meropenem-resistant strains > 256 µg/ml; and of two chloramphenicol-susceptible isolates (by disc diffusion method) 6 µg/ml (considered as intermediate susceptible). Multiple- antibiotics resistance was detected in 15% of the strains, with resistance to 2, 3, 4, 5 and 6 antibiotics in 8.5%, 4%, 2%, 0.5% and 0.5% of the isolates, respectively. By identifying beta-lactamase-negative ampicillin-resistant H. influenzae, empirical therapy with beta-lactam/beta-lactamase inhibitor combinations and second generation cephalosporins would be inappropriate for such patients (approximately 3%). Our findings will

  8. Antimicrobial resistance among invasive Haemophilus influenzae strains: results of a Brazilian study carried out from 1996 through 2000

    Directory of Open Access Journals (Sweden)

    Casagrande S.T.

    2002-01-01

    Full Text Available A total of 1712 strains of Haemophilus influenzae isolated from patients with invasive diseases were obtained from ten Brazilian states from 1996 to 2000. ß-Lactamase production was assessed and the minimum inhibitory concentrations (MIC of ampicillin, chloramphenicol, ceftriaxone and rifampin were determined using a method for broth microdilution of Haemophilus test medium. The prevalence of strains producing ß-lactamase ranged from 6.6 to 57.7%, with an overall prevalence of 18.4%. High frequency of ß-lactamase-mediated ampicillin resistance was observed in Distrito Federal (25%, São Paulo (21.7% and Paraná (18.5%. Of the 1712 strains analyzed, none was ß-lactamase negative, ampicillin resistant. A total of 16.8% of the strains were resistant to chloramphenicol, and 13.8% of these also presented resistance to ampicillin, and only 3.0% were resistant to chloramphenicol alone. All strains were susceptible to ceftriaxone and rifampin and the MIC90 were 0.015 µg/ml and 0.25 µg/ml, respectively. Ceftriaxone is the drug of choice for empirical treatment of bacterial meningitis in pediatric patients who have not been screened for drug susceptibility. The emergence of drug resistance is a serious challenge for the management of invasive H. influenzae disease, which emphasizes the fundamental role of laboratory-based surveillance for antimicrobial resistance.

  9. Haemophilus influenzae Disease (Including Hib) Symptoms

    Science.gov (United States)

    ... Search The CDC Cancel Submit Search The CDC Haemophilus influenzae Disease (Including Hib) Note: Javascript is disabled or ... and Symptoms Recommend on Facebook Tweet Share Compartir Haemophilus influenzae , including Hib, disease causes different symptoms depending on ...

  10. rRNA gene restriction patterns of Haemophilus influenzae biogroup aegyptius strains associated with Brazilian purpuric fever.

    Science.gov (United States)

    Irino, K; Grimont, F; Casin, I; Grimont, P A

    1988-08-01

    The rRNA gene restriction patterns of 92 isolates of Haemophilus influenzae biogroup aegyptius, associated with conjunctivitis or Brazilian purpuric fever in the State of São Paulo, Brazil, were studied with 16 + 23S rRNA from Escherichia coli as a probe. All strains were classified into 15 patterns. Isolates from Brazilian purpuric fever cases were seen only in patterns 3 (most frequently) and 4 (rarely), whereas isolates from conjunctivitis were found in all 15 patterns. The study demonstrated that rRNA from E. coli can serve as a probe for molecular epidemiology.

  11. Haemophilus haemolyticus: A Human Respiratory Tract Commensal to Be Distinguished from Haemophilus influenzae

    DEFF Research Database (Denmark)

    Murphy, T.F.; Brauer, A.L.; Sethi, S.

    2007-01-01

    Background. Haemophilus influenzae is a common pathogen in adults with chronic obstructive pulmonary disease (COPD). In a prospective study, selected isolates of apparent H. influenzae had an altered phenotype. We tested the hypothesis that these variant strains were genetically different from ty...... distinguish H. haemolyticus from H. influenzae. H. haemolyticus is a respiratory tract commensal. The recognition that some strains of apparent H. influenzae are H. haemolyticus substantially strengthens the association of true H. influenzae with clinical infection....

  12. Human microvascular endothelial cell toxicity caused by Brazilian purpuric fever-associated strains of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Weyant, R S; Quinn, F D; Utt, E A; Worley, M; George, V G; Candal, F J; Ades, E W

    1994-02-01

    An in vitro cytotoxicity model that uses an immortalized human microvascular endothelial cell line (HMEC-1) differentiates Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius (HAE) strains from non-BPF-associated HAE strains. Toxic strains produced a characteristic HMEC-1 phenotype at an MOI of 1000 bacteria/TCC to produce an observable effect. The cytotoxic phenotype was characterized by the presence of large clumps of HMEC-1 cells, which detached from the monolayer within 48 h of inoculation by HAE cells. The cytotoxic phenotype was observed with 100% of BPF-associated HAE (40/40) and 14% of non-BPF-associated HAE (8/57; P < .001). The ability to study a BPF-associated phenotype in vitro using human microvascular cells should enhance our knowledge of BPF pathogenesis.

  13. Hydrogen peroxide scavenging is not a virulence determinant in the pathogenesis of Haemophilus influenzae type b strain Eagan

    Directory of Open Access Journals (Sweden)

    Van Beeumen Jozef J

    2006-01-01

    Full Text Available Abstract Background A potentially lethal flux of hydrogen peroxide (H2O2 is continuously generated during aerobic metabolism. It follows that aerobic organisms have equipped themselves with specific H2O2 dismutases and H2O2 reductases, of which catalase and the alkyl hydroperoxide reductase (AhpR are the best-studied prokaryotic members. The sequenced Haemophilus influenzae Rd genome reveals one catalase, designated HktE, and no AhpR. However, Haemophilus influenzae type b strain Eagan (Hib, a causative agent of bacterial sepsis and meningitis in young children, disrupted in its hktE gene is not attenuated in virulence, and retains the ability to rapidly scavenge H2O2. This redundancy in H2O2-scavenging is accounted for by peroxidatic activity which specifically uses glutathione as the reducing substrate. Results We show here that inside acatalasaemic H. influenzae all of the residual peroxidatic activity is catalyzed by PGdx, a hybrid peroxiredoxin-glutaredoxin glutathione-dependent peroxidase. In vitro kinetic assays on crude hktE- pgdx- H. influenzae Rd extracts revealed the presence of NAD(PH:peroxide oxidoreductase activity, which, however, appears to be physiologically insignificant because of its low affinity for H2O2 (Km = 1.1 mM. Hydroperoxidase-deficient hktE- pgdx- H. influenzae Rd showed a slightly affected aerobic growth phenotype in rich broth, while, in chemically defined medium, growth was completely inhibited by aerobic conditions, unless the medium contained an amino acid/vitamin supplement. To study the role of PGdx in virulence and to assess the requirement of H2O2-scavenging during the course of infection, both a pgdx single mutant and a pgdx/hktE double mutant of Hib were assayed for virulence in an infant rat model. The ability of both mutant strains to cause bacteremia was unaffected. Conclusion Catalase (HktE and a sole peroxidase (PGdx account for the majority of scavenging of metabolically generated H2O2 in the H

  14. MICROBIOLOGICAL CHARACTERISATION OF Haemophilus influenzae STRAINS ISOLATED FROM PATIENTS WITH INVASIVE AND RESPIRATORY DISEASES

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    Tomislav Kostyanev

    2010-01-01

    Full Text Available A total of 175 H. influenzae strains were collected between 1994 and 2009 from all aged patient groups. The strains were isolated from patients with invasive and community-acquired respiratory tract infections. All strains were identified according to standard microbiological methods. Serotyping was done by a coagglutination test and by molecular PCR capsular genotyping. Beta-lactamase production was determined by the chromogenic cephalosporin test with nitrocephin as substrate. Most of the isolated H. influenzae strains were from children under 5 years of age (57.7%. Overall, 61 strains belonged to serotype b (34.9% by the means of PCR capsular typing, 1 strain was type f, and 113 isolates (64.6% were non-typeable (non-encapsulated H. influenzae. Among the infants and children with meningitis or other invasive infections, aged 2 month to 5 years, all strains, except one, were serotype b. In respiratory tract infections (pneumonia, otitis media, sinusitis and people with chronic pulmonary diseases - exacerbations of COPD, bronchiectasis, cystic fibrosis the most common - 96.5% were non-typeable strains in both groups children and adults. Overall, the prevalence of beta-lactamase production was 19.4%. But, it was much higher for invasive strains from CSF isolates - 37.7%, 25% in blood samples, and 37.5% in otitis media causative strains. Beta-lactamase production was less frequent in respiratory tract isolates - in sputum 13.3% and in URT samples - 2.3%. The rate of beta-lactamase production in CSF isolates has not changed for the last 10 years.PCR capsular genotyping method has to be performed for all non-b-type strains. The implementation of Hib vaccine in our country will be accompanied by a reduction in invasive diseases caused by H. influenzae type b in children, but it is not useful in preventing infections caused by non-typeable H. influenzae strains.

  15. Purification and characterization of a pilin specific for Brazilian purpuric fever-associated Haemophilus influenzae biogroup aegyptius (H. aegyptius) strains.

    Science.gov (United States)

    Weyant, R S; Bibb, W F; Stephens, D S; Holloway, B P; Moo-Penn, W F; Birkness, K A; Helsel, L O; Mayer, L W

    1990-04-01

    Brazilian purpuric fever (BPF) is a recently described fatal pediatric disease caused by systemic infection with Haemophilus influenzae biogroup aegyptius. Previous studies have shown that all H. influenzae biogroup aegyptius strains isolated from BPF cases and case contacts share several unique phenotypic and genotypic characteristics that differentiate them from other H. influenzae biogroup aegyptius strains isolated from conjunctivitis cases in Brazil. One key characteristic of this BPF clone is reactivity in a BPF-specific monoclonal antibody enzyme-linked immunosorbent assay. We have purified and partially characterized a pilin, referred to as the 25-kilodalton (kDa) protein. Aggregates of this protein contain a heat-labile epitope which is recognized by a monoclonal antibody used in the BPF-specific enzyme-linked immunosorbent assay. The protein has a molecular weight of approximately 25,000, is insoluble in most detergents, and fractionates with outer membrane vesicles after LiCl extraction. Biochemical analysis of the 25-kDa protein shows it to have an amino acid composition similar but not identical to that of the H. influenzae type b pilin. The sequence of 20 N-terminal amino acids of the 25-kDa protein shows almost complete homology with the N terminus of the H. influenzae type b pilin and the types 1 and P pilins of Escherichia coli. Transmission electron microscopic analysis of the purified protein shows the presence of filamentous structures similar in morphology to those of H. influenzae pili. Reactivity between the 25-kDa protein and the BPF-specific monoclonal antibody is demonstrated by Western blotting (immunoblotting) and colloidal gold-enhanced immunoelectron microscopy. Hemadsorption analysis shows that expression of this protein is associated with increases in piliated cells and enhanced binding of these cells to human erythrocytes. These studies indicate that expression of the 25-kDa protein is a characteristic unique to the BPF clone and

  16. Repair of ultraviolet-damaged transforming DNA in a mismatch repair-deficient strain of Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Bagci, H.; Stuy, J.H. (Florida State Univ., Tallahassee (USA). Dept. of Biological Science)

    1982-03-01

    Ultraviolet inactivation of Haemophilus influenzae transforming DNA followed inverse square root kinetics in both mismatch repair-proficient (hex/sup +/) and deficient (hex-1) recipients. No DNA concentration effect was seen with UV-excision repair-deficient (uvr/sup -/) strains. Low-efficiency genetic markers remained more sensitive than high-efficiency ones when they were assayed on excision repair-deficient hex/sup +/ uvr/sup -/ strains. They were equally resistant when hex/sup -/ uvr/sup -/ recipients were used. This was explained by assuming that recombinational repair of UV lesions in the donor strand and mismatch repair of the recipient strand may overlap and cause double strand interruptions. This will eliminate low-efficiency transformants.

  17. Expression of an immunoreactive 72 kDa protein in strains of Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever.

    Science.gov (United States)

    Lesse, A J; Bittner, W E

    1993-10-01

    Brazilian purpuric fever (BPF) is a newly described pediatric syndrome that results in significant morbidity and mortality. BPF is caused by specific phenotypic strains of Haemophilus influenzae biogroup aegyptius that are capable of intravascular survival. Immunoblotting of outer membrane proteins of H. influenzae biogroup aegyptius with normal human serum showed that most virulent strains of H. influenzae biogroup aegyptius associated with BPF expressed an immunologically prominent protein at 72 kDa. A corresponding protein in avirulent isolates migrated at 79 kDa. Although a minor component on SDS-PAGE analysis of the outer membrane, specific antibody against this protein is present in high concentrations in normal human serum.

  18. Deoxyribonucleic acid relatedness between Haemophilus aegyptius and Haemophilus influenzae.

    Science.gov (United States)

    Casin, I; Grimont, F; Grimont, P A

    1986-01-01

    Haemophilus aegyptius should be considered a junior subjective synonym of Haemophilus influenzae. Both nomenspecies are indistinguishable by DNA/DNA hybridization (S1 nuclease method). No single phenotypic test can unambigously separate H. aegyptius from the other biotypes of H. influenzae.

  19. Synthesis of histamine by Haemophilus influenzae.

    Science.gov (United States)

    Sheinman, B D; Devalia, J L; Davies, R J; Crook, S J; Tabaqchali, S

    1986-03-29

    Recent findings suggest that bacteria might contribute to histamine concentrations in the sputum of patients with infective lung disease. Ten isolates of Haemophilus influenzae from patients with acute exacerbation of chronic bronchitis and emphysema, together with two reference strains, were incubated at 37 degrees C for 72 hours. Serial estimations of histamine concentrations by high pressure liquid chromatography showed significant increases at 24 and 48 hours; no increases were evident in the control samples. These findings suggest that H influenzae might contribute to inflammation and limited airflow in infective lung disease by producing histamine.

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

    DEFF Research Database (Denmark)

    Ronit, Andreas; Berg, Ronan M G; Bruunsgaard, Helle;

    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...

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

    Science.gov (United States)

    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.

  2. Meningitis due to Haemophilus influenzae type f.

    Science.gov (United States)

    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.

  3. Heat sensitivity of Haemophilus influenzae containing defective prophage

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.

    1977-12-01

    Strains of Haemophilus influenzae that carry a defective prophage are more sensitive to heat than is a strain that does not, even in the presence of a rec-I mutation, which normally renders prophage noninducible. The prophage of HPlcl, a nondefective phage, does not affect the heat sensitivity.

  4. Prevalence of Haemophilus influenzae carriers in the Catalan preschool population. Working Group on Invasive Disease Caused by Haemophilus influenzae.

    Science.gov (United States)

    Fontanals, D; Bou, R; Pons, I; Sanfeliu, I; Domínguez, A; Pineda, V; Renau, J; Muñoz, C; Latorre, C; Sanchez, F

    2000-04-01

    This study was designed to determine the prevalence of healthy Haemophilus influenzae carriers in a random sample of the preschool population in Catalonia. Oropharyngeal swabs were collected and cultured on chocolate agar supplemented with 260 microg/ml of bacitracin. Four hundred two of the 734 (54.8%) children studied were detected as Haemophilus influenzae carriers: 7 (0.9%) carried serotype b, 14 (1.9%) serotype e, 6 (0.8%) serotype f, and 375 (51%) carried nontypable strains. The results show that, although the prevalence of Haemophilus influenzae carriers is similar to figures reported from other countries, the prevalence of Haemophillus influenzae serotype b carriers is lower and corresponds with the low incidence of invasive disease observed in the Catalan community.

  5. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  6. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2014. In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000...

  7. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  8. NNDSS - Table II. Giardiasis to Haemophilus influenza

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Giardiasis to Haemophilus influenza - 2016. In this Table, provisional* cases of selected†notifiable diseases (≥1,000 cases reported during the...

  9. Haemophilus influenzae Disease (Including Hib) Diagnosis and Treatment

    Science.gov (United States)

    ... Search The CDC Cancel Submit Search The CDC Haemophilus influenzae Disease (Including Hib) Note: Javascript is disabled or ... Compartir On this Page Diagnosis Treatment Complications Diagnosis Haemophilus influenzae , including Hib, disease is usually diagnosed with one ...

  10. Transcriptional profile of Haemophilus influenzae: effects of iron and heme.

    Science.gov (United States)

    Whitby, Paul W; Vanwagoner, Timothy M; Seale, Thomas W; Morton, Daniel J; Stull, Terrence L

    2006-08-01

    Haemophilus influenzae requires either heme or a porphyrin and iron source for growth. Microarray studies of H. influenzae strain Rd KW20 identified 162 iron/heme-regulated genes, representing approximately 10% of the genome, with > or =1.5-fold changes in transcription in response to iron/heme availability in vitro. Eighty genes were preferentially expressed under iron/heme restriction; 82 genes were preferentially expressed under iron/heme-replete conditions.

  11. Nicotinamide ribosyl uptake mutants in Haemophilus influenzae.

    Science.gov (United States)

    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.

  12. 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.

    Science.gov (United States)

    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.

  13. Haemophilus influenzae triggers autophagy in HEp-2 cells.

    Science.gov (United States)

    Espinoza-Mellado, María del Rosario; Reyes-Picaso, Carolina; Garcés-Pérez, Miriam S; Jardón-Serrano, Cynthia V; López-Villegas, Edgar O; Giono-Cerezo, Silvia

    2016-03-01

    The MAP-LC3 system regulates the intracellular formation of autophagy-associated vacuoles. These vacuoles contain the LC3 protein; thus it has been utilized as a marker to identify autophagosomes. The aim of our study was to investigate whether Haemophilus influenzae strains and their supernatants could activate autophagy in human larynx carcinoma cell line (HEp-2). We demonstrate that higher expression of the LC3B-II protein was induced, particularly by nontypeable Haemophilus influenzae (NTHi) 49766 and by supernatants, containing <50 kDa proteins, of both strains. Ultrastructural studies demonstrate vacuoles with a double membrane and/or membrane material inside, showing similar features to those of autophagic vacuoles. Together, our findings demonstrate that H. influenzae strains and their supernatants trigger an autophagic process.

  14. Comparison of outer membrane protein and biochemical profiles of Haemophilus aegyptius and Haemophilus influenzae biotype III.

    Science.gov (United States)

    Carlone, G M; Sottnek, F O; Plikaytis, B D

    1985-11-01

    Haemophilus aegyptius and Haemophilus influenzae biotype III are morphologically and biochemically similar; however, their outer membrane protein (Sarkosyl insoluble) profiles are distinct. Of 18 strains of H. aegyptius examined, 15 had a type 1 protein profile, and 3 had a type 2 profile, whereas the 5 strains of H. influenzae biotype III examined had three other protein profile types. All Haemophilus strains examined had 31- and 76-kilodalton (kDa) proteins and minor proteins with molecular masses between 20 and 100 kDa. H. aegyptius, with a type 1 protein profile, had major outer membrane proteins with apparent molecular masses of 27, 35.5, and 41.5 kDa, and H. aegyptius, with a type 2 protein profile, had 26-, 29-, 39.5-, and 41-kDa proteins. The type strain of H. influenzae biotype III had three major outer membrane proteins with apparent molecular masses of 29, 38.5 and 40 kDa. Four other strains designated as H. influenzae biotype III had major outer membrane proteins between 27 and 41.5 kDa representing two additional protein profiles.

  15. Children with Haemophilus influenzae type b (Hib) vaccine failure have long-term bactericidal antibodies against virulent Hib strains with multiple capsular loci.

    Science.gov (United States)

    Townsend-Payne, Kelly; Ladhani, Shamez N; Findlow, Helen; Slack, Mary; Borrow, Ray

    2016-07-25

    Children who develop invasive Haemophilus influenzae serotype b (Hib) disease after immunisation with a highly-effective conjugate vaccine are more likely to have been infected with Hib strains possessing multiple copies of the capsulation locus. Using a recently-validated serum bactericidal antibody (SBA) assay, we tested convalescent sera from 127 Hib vaccine failure cases against clinical Hib strains expressing 1-5 copies of the capsulation locus. SBA titres correlated weakly with anti-capsular IgG antibody concentrations and there was no association between SBA geometric mean titres and number of capsulation locus copies. After infection, children with Hib vaccine failure were equally protected against Hib strains with 1-5 copies of the capsulation locus.

  16. Outer membrane protein profiling to distinguish between Haemophilus aegyptius and non-capsulate Haemophilus influenzae biotype III.

    Science.gov (United States)

    Leaves, N I; Anderson, E C; Toy, S J

    1994-12-01

    Outer membrane protein profiling was used to assist in determining the identity of an isolate of Haemophilus spp. that was presumptively identified as non-capsulate Haemophilus influenzae biotype III. The possibility that this strain was in fact Haemophilus aegyptius was queried because of clinical information and the source of the isolate. Sodium dodecyl-sulphate polyacrylamide gel electrophoresis was used to establish the identity of the isolate as non-capsulate H. influenzae biotype III and no H. aegyptius. Generally, protein profiling compared very favourably with other standard tests for identifying H. aegyptius: the method was easily and rapidly performed and gave an unequivocal result.

  17. Characterization of the IgA1 protease from the Brazilian purpuric fever strain F3031 of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    McGillivary, Glen; Smoot, Laura M; Actis, Luis A

    2005-09-15

    Brazilian purpuric fever is a severe vascular disease caused by an invasive clone of Haemophilus influenzae biogroup aegyptius, which normally causes self-limiting eye infections. A previous genome subtraction procedure resulted in the isolation of a DNA fragment, which encodes a putative IgA1 protease, specific to the F3031 Brazilian purpuric fever type strain. Cloning and sequencing of the entire F3031 iga1 gene showed that the subtracted DNA fragment encompasses the iga1 region encoding the active site and the cleavage specificity determinant of the protein, which are different from the cognate regions of the proteases produced by other H. influenzae strains. Western and IgA cleavage assays together with clustering analysis showed that the F3031 IgA1 protease is most similar to the type 2 proteases produced by H. influenzae type c and e strains. Analysis of the promoter region of the F3031 iga1 gene revealed the presence of Fur binding sites. However, real-time PCR analysis and transcriptional fusion assays showed that the expression of iga1 is not regulated by iron or hemin under the conditions tested.

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

    Science.gov (United States)

    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

  19. Recurrent Posttraumatic Meningitis due to Nontypable Haemophilus influenzae: Case Report and Review of the Literature

    DEFF Research Database (Denmark)

    Kunze, W; Müller, L; Kilian, Mogens;

    2007-01-01

    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...

  20. Phase-variable expression of the 145-kDa surface protein of Brazilian purpuric fever case-clone strains of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Rubin, L G

    1995-03-01

    Clonally related strains of Haemophilus influenzae biogroup aegyptius have recently been associated with Brazilian purpuric fever (BPF). Antibodies to a 145-kDa minor outer membrane protein (P145) are bactericidal and protect against experimental bacteremia. To determine if P145 is conserved among case-clone strains, case-clone strains were screened for P145 expression. Assays of a large number of colonies of each strain using colony immunoblot revealed colonies reactive with anti-P145 sera in all 17 case-clone strains. P145 was expressed at a low frequency (0.08%-2.2% of colonies) in 14 strains and at a high frequency (> 98%) in 3 strains. Expression of P145 by reactive colonies was confirmed by SDS-PAGE. Also, anti-P145-nonreactive variant colonies of P145-expressing strains were detected in 0.4%-1.5% of colonies. These findings indicate P145 is conserved among BPF case-clone strains and is subject to phase-variable expression.

  1. Plasmid recombination in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, D.

    1982-01-01

    DNA recombination in exponential phase and competent Haemophilus influenzae was measured by an electron microscopic assay that relies on the conversion of plasmid RSF0885 monomers into multimeric forms. Dimer circles were present at a frequency of 2% in plasmid preparations from competent Rd (wild-type) cells; multimers were present at a frequency of 0.2% in preparations from exponential phase cells. Thus, plasmid recombination was stimulated in competent cells. Multimer formation occurred efficiently in cells of the transformation defective mutant rec2, implying that the rec2 gene product is not required for plasmid recombination. However, the absence of multimer plasmids in preparations from competent cells of the transformation defective mutant rec1 suggests that the rec1 gene product is required. Digestion of purified plasmids with restriction endonuclease PvuII, which makes a single cut in the monomer, revealed the presence of recombination intermediates composed of two linear plasmids joined to form two pairs of arms resembling the Greek letter chi. Length measurements of these arms taken from a population of recombination intermediates gave evidence that the plasmids were joined at sites of homology. The distributions of individual DNA strands, at the intersections of the four arms, could be resolved in some recombination intermediates and were of two types. The first type of junction appeared as a single-stranded arm appended to each corner. The second type of junction consisted of a single strand of DNA linking the two linear plasmids at a site of homology. The single-stranded linker was frequently situated at the edge of a short gap on one of the plasmids in the pair. The fine structures of the recombinational joints have been interpreted in terms of previously proposed models of recombination.

  2. Identification of Haemophilus influenzae type b by a monoclonal antibody coagglutination assay.

    OpenAIRE

    Hamel, J.; Brodeur, B R; Belmaaza, A; Montplaisir, S; Musser, J M; Selander, R K

    1987-01-01

    A coagglutination assay using monoclonal antibody is described for the identification of Haemophilus influenzae type b. An immunoglobulin G2a monoclonal antibody, Hb-2, directed against a serotype-specific outer membrane protein of H. influenzae type b was adsorbed to Staphylococcus aureus Cowan 1 cells. In a dot enzyme immunoassay, Hb-2 reacted with 453 of 455 H. influenzae type b isolates and did not react with H. influenzae of other serotypes, untypeable H. influenzae strains, or other bac...

  3. Characterization of the N-Acetyl-5-neuraminic Acid-binding Site of the Extracytoplasmic Solute Receptor (SiaP) of Nontypeable Haemophilus influenzae Strain 2019

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Jason W.; Coussens, Nathan P.; Allen, Simon; Houtman, Jon C.D.; Turner, Keith H.; Zaleski, Anthony; Ramaswamy, S.; Gibson, Bradford W.; Apicella, Michael A. (Iowa); (Buck Inst.)

    2012-11-14

    Nontypeable Haemophilus influenzae is an opportunistic human pathogen causing otitis media in children and chronic bronchitis and pneumonia in patients with chronic obstructive pulmonary disease. The outer membrane of nontypeable H. influenzae is dominated by lipooligosaccharides (LOS), many of which incorporate sialic acid as a terminal nonreducing sugar. Sialic acid has been demonstrated to be an important factor in the survival of the bacteria within the host environment. H. influenzae is incapable of synthesizing sialic acid and is dependent on scavenging free sialic acid from the host environment. To achieve this, H. influenzae utilizes a tripartite ATP-independent periplasmic transporter. In this study, we characterize the binding site of the extracytoplasmic solute receptor (SiaP) from nontypeable H. influenzae strain 2019. A crystal structure of N-acetyl-5-neuraminic acid (Neu5Ac)-bound SiaP was determined to 1.4 {angstrom} resolution. Thermodynamic characterization of Neu5Ac binding shows this interaction is enthalpically driven with a substantial unfavorable contribution from entropy. This is expected because the binding of SiaP to Neu5Ac is mediated by numerous hydrogen bonds and has several buried water molecules. Point mutations targeting specific amino acids were introduced in the putative binding site. Complementation with the mutated siaP constructs resulted either in full, partial, or no complementation, depending on the role of specific residues. Mass spectrometry analysis of the O-deacylated LOS of the R127K point mutation confirmed the observation of reduced incorporation of Neu5Ac into the LOS. The decreased ability of H. influenzae to import sialic acid had negative effects on resistance to complement-mediated killing and viability of biofilms in vitro, confirming the importance of sialic acid transport to the bacterium.

  4. Characterization of the N-acetyl-5-neuraminic acid-binding site of the extracytoplasmic solute receptor (SiaP) of nontypeable Haemophilus influenzae strain 2019.

    Science.gov (United States)

    Johnston, Jason W; Coussens, Nathan P; Allen, Simon; Houtman, Jon C D; Turner, Keith H; Zaleski, Anthony; Ramaswamy, S; Gibson, Bradford W; Apicella, Michael A

    2008-01-11

    Nontypeable Haemophilus influenzae is an opportunistic human pathogen causing otitis media in children and chronic bronchitis and pneumonia in patients with chronic obstructive pulmonary disease. The outer membrane of nontypeable H. influenzae is dominated by lipooligosaccharides (LOS), many of which incorporate sialic acid as a terminal nonreducing sugar. Sialic acid has been demonstrated to be an important factor in the survival of the bacteria within the host environment. H. influenzae is incapable of synthesizing sialic acid and is dependent on scavenging free sialic acid from the host environment. To achieve this, H. influenzae utilizes a tripartite ATP-independent periplasmic transporter. In this study, we characterize the binding site of the extracytoplasmic solute receptor (SiaP) from nontypeable H. influenzae strain 2019. A crystal structure of N-acetyl-5-neuraminic acid (Neu5Ac)-bound SiaP was determined to 1.4A resolution. Thermodynamic characterization of Neu5Ac binding shows this interaction is enthalpically driven with a substantial unfavorable contribution from entropy. This is expected because the binding of SiaP to Neu5Ac is mediated by numerous hydrogen bonds and has several buried water molecules. Point mutations targeting specific amino acids were introduced in the putative binding site. Complementation with the mutated siaP constructs resulted either in full, partial, or no complementation, depending on the role of specific residues. Mass spectrometry analysis of the O-deacylated LOS of the R127K point mutation confirmed the observation of reduced incorporation of Neu5Ac into the LOS. The decreased ability of H. influenzae to import sialic acid had negative effects on resistance to complement-mediated killing and viability of biofilms in vitro, confirming the importance of sialic acid transport to the bacterium.

  5. Invasive Disease Caused by Nontypeable Haemophilus Influenzae

    Centers for Disease Control (CDC) Podcasts

    2015-11-12

    Dr. Elizabeth Briere discusses Nontypeable Haemophilus influenzae which causes a variety of infections in children and adults.  Created: 11/12/2015 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/17/2015.

  6. Nationwide survey of the development of drug resistance in the pediatric field in 2007, 2010, and 2012: drug sensitivity of Haemophilus influenzae serotype b strain in Japan.

    Science.gov (United States)

    Baba, Hiroaki; Sato, Yoshitake; Toyonaga, Yoshikiyo; Hanaki, Hideaki; Sunakawa, Keisuke

    2015-04-01

    Based on the results of surveillance in the pediatric field conducted in 2007, 2010, and 2012, we examined the frequency of Haemophilus influenzae serotype b (Hib) strains, the susceptibility for Hib strains to various types of antimicrobial agent, and the relations to patients' background factors. Among all of Haemophilus influenzae, the frequency of Hib strains was 3.6% (14/386 strains) in 2007, 4.8% (23/484 strains) in 2010, 1.2% (5/411 strains) in 2012, and decreasing in 2012. Hib strains were isolated in patients with the following infections: nine patients with respiratory tract infections (upper respiratory tract infection, bronchitis, and pneumonia), three patients with sepsis, one patient with meningitis, and one patient with purulent inflammation of a tendon sheath in 2007; 11 patients with respiratory tract infections (upper respiratory tract infection, bronchitis, and pneumonia), four patients with sepsis, and eight patients with meningitis in 2010, demonstrating a relatively high frequency in patients with invasive infections. However, in 2012, Hib strains were isolated in only four patients with respiratory tract infections (upper respiratory tract infection) and one patient with bronchial asthma. Evaluation of background factors with pediatric patients in whom Hib strains were isolated showed that approximately 70% were male; majority was children under three years of age; and higher detection rates were also related to the background of patients who were attendant to daycare center, had siblings, had received no antimicrobial agents within the previous one month before collecting specimens. Throughout the surveillance between 2007 and 2012, antimicrobial agents with all phases' MICs ≤ 1 μg/mL were cefditoren, cefcapene, and cefteram in the oral β-lactams; tazobactam/piperacillin, ceftriaxone, cefotaxime, and meropenem in the injectable β-lactams; azithromycin in the macrolide; and levofloxacin in the quinolone. After 2010, MIC ranges were

  7. Transformation of Haemophilus influenzae by recombinant molecules

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.; McCarthy, D.R.; Clayton, N.L.

    1981-01-01

    A gene library of Haemophilus influenzae DNA has been constructed by ligating chromosomal DNA from cells resistant to a number of antibiotics, together with DNA of the H. influenzae plasmid RSF0885. Before ligation both DNAs were cut with the enzyme PvuII. The ligated DNA was allowed to enter competent H. influenzae sensitive to the antibiotics and selection was made for resistance to ampicillin, conferred by the plasmid RSF0885 DNA. Plasmids conferring resistance to various other antibiotics, as well as to ampicillin, have been obtained by this procedure and subsequent selection for chromosomal markers.

  8. Prevalence of genetic differences in phosphorylcholine expression between nontypeable Haemophilus influenzae and Haemophilus haemolyticus

    Directory of Open Access Journals (Sweden)

    Marrs Carl F

    2010-11-01

    Full Text Available Abstract Background Although non-typeable (NT Haemophilus influenzae and Haemophilus haemolyticus are closely related human commensals, H. haemolyticus is non-pathogenic while NT H. influenzae is an important cause of respiratory tract infections. Phase-variable phosphorylcholine (ChoP modification of lipooligosaccharide (LOS is a NT H. influenzae virulence factor that, paradoxically, may also promote complement activation by binding C-reactive protein (CRP. CRP is known to bind more to ChoP positioned distally than proximally in LOS, and the position of ChoP within LOS is dictated by specific licD alleles (designated here as licDI, licDIII, and licDIV that are present in a lic1 locus. The lic1 locus contains the licA-licD genes, and ChoP-host interactions may also be influenced by a second lic1 locus that allows for dual ChoP substitutions in the same strain, or by the number of licA gene tetranucleotide repeats (5'-CAAT-3' that reflect phase-variation mutation rates. Results Using dot-blot hybridization, 92% of 88 NT H. influenzae and 42.6% of 109 H. haemolyticus strains possessed a lic1 locus. Eight percent of NT H. influenzae and none of the H. haemolyticus strains possessed dual copies of lic1. The licDIII and licDIV gene alleles were distributed similarly (18-22% among the NT H. influenzae and H. haemolyticus strains while licDI alleles were present in 45.5% of NT H. influenzae but in less than 1% of H. haemolyticus strains (P H. influenzae had an average of 26.8 tetranucleotide repeats in licA compared to14.8 repeats in H. haemolyticus (P H. influenzae strains that possessed a licDIII allele had increased numbers of repeats compared to NT H. influenzae with other licD alleles (P Conclusions These data demonstrate that genetic similarities and differences of ChoP expression exist between NT H. influenzae and H. haemolyticus and strengthen the hypothesis that, at the population level, these differences may, in part, provide an advantage in

  9. Lineage-specific virulence determinants of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

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

    2012-03-01

    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.

  10. MALDI-TOF MS distinctly differentiates nontypable Haemophilus influenzae from Haemophilus haemolyticus.

    Science.gov (United States)

    Zhu, Bingqing; Xiao, Di; 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.

  11. Increased biofilm formation by nontypeable Haemophilus influenzae isolates from patients with invasive disease or otitis media versus strains recovered from cases of respiratory infections

    NARCIS (Netherlands)

    Puig, C.; Domenech, A.; Garmendia, J.; Langereis, J.D.; Mayer, P.; Calatayud, L.; Linares, J.; Ardanuy, C.; Marti, S.

    2014-01-01

    Biofilm formation by nontypeable (NT) Haemophilus influenzae remains a controversial topic. Nevertheless, biofilm-like structures have been observed in the middle-ear mucosa of experimental chinchilla models of otitis media (OM). To date, there have been no studies of biofilm formation in large coll

  12. Increased biofilm formation by nontypeable Haemophilus influenzae isolates from patients with invasive disease or otitis media versus strains recovered from cases of respiratory infections

    NARCIS (Netherlands)

    Puig, C.; Domenech, A.; Garmendia, J.; Langereis, J.D.; Mayer, P.; Calatayud, L.; Linares, J.; Ardanuy, C.; Marti, S.

    2014-01-01

    Biofilm formation by nontypeable (NT) Haemophilus influenzae remains a controversial topic. Nevertheless, biofilm-like structures have been observed in the middle-ear mucosa of experimental chinchilla models of otitis media (OM). To date, there have been no studies of biofilm formation in large

  13. Identification of Haemophilus influenzae and Haemophilus haemolyticus by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Bruin, J P; Kostrzewa, M; van der Ende, A; Badoux, P; Jansen, R; Boers, S A; Diederen, B M W

    2014-02-01

    Generally accepted laboratory methods that have been used for decades do not reliably distinguish between H. influenzae and H. haemolyticus isolates. H. haemolyticus strains are often incorrectly identified as nontypeable Haemophilus influenzae (NTHi). To distinguish H. influenzae from H. haemolyticus we have created a new database on the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) bio-typer 2 and compared the results with routine determination of Haemophilus (growth requirement for X and V factor), and multilocus sequence typing (MLST). In total we have tested 277 isolates, 244 H. influenzae and 33 H. haemolyticus. Using MLST as the gold standard, the agreement of MALDI-TOF MS was 99.6 %. MALDI-TOF MS allows reliable and rapid discrimination between H. influenzae and H. haemolyticus.

  14. Haemophilus haemolyticus is infrequently misidentified as Haemophilus influenzae in diagnostic specimens in Australia.

    Science.gov (United States)

    Zhang, Bowen; Kunde, Dale; Tristram, Stephen

    2014-12-01

    The commensal Haemophilus haemolyticus is difficult to differentiate from the respiratory pathogen Haemophilus influenzae using phenotypic tests. In a study that used molecular tests to retrospectively identify 447 phenotypically identified H. influenzae isolates from diagnostic specimens in Australia, only 7 (1.5%) H. haemolyticus were identified.

  15. Invasive Haemophilus influenzae Infection in Patients With Cancer.

    Science.gov (United States)

    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.

  16. Identification of a siderophore utilization locus in nontypeable Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Seale Thomas W

    2010-04-01

    Full Text Available Abstract Background Haemophilus influenzae has an absolute aerobic growth requirement for either heme, or iron in the presence of protoporphyrin IX. Both iron and heme in the mammalian host are strictly limited in their availability to invading microorganisms. Many bacterial species overcome iron limitation in their environment by the synthesis and secretion of small iron binding molecules termed siderophores, which bind iron and deliver it into the bacterial cell via specific siderophore receptor proteins on the bacterial cell surface. There are currently no reports of siderophore production or utilization by H. influenzae. Results Comparative genomics revealed a putative four gene operon in the recently sequenced nontypeable H. influenzae strain R2846 that encodes predicted proteins exhibiting significant identity at the amino acid level to proteins involved in the utilization of the siderophore ferrichrome in other bacterial species. No siderophore biosynthesis genes were identified in the R2846 genome. Both comparative genomics and a PCR based analysis identified several additional H. influenzae strains possessing this operon. In growth curve assays strains containing the genes were able to utilize ferrichrome as an iron source. H. influenzae strains lacking the operon were unable to obtain iron from ferrichrome. An insertional mutation in one gene of the operon abrogated the ability of strains to utilize ferrichrome. In addition transcription of genes in the identified operon were repressible by high iron/heme levels in the growth media. Conclusions We have identified an iron/heme-repressible siderophore utilization locus present in several nontypeable H. influenzae strains. The same strains do not possess genes encoding proteins associated with siderophore synthesis. The siderophore utilization locus may enable the utilization of siderophores produced by other microorganisms in the polymicrobial environmental niche of the human nasopharynx

  17. Predicted configurations of oligosaccharide extensions in the lipooligosaccharide of nontypeable Haemophilus influenzae isolates.

    Science.gov (United States)

    McCrea, Kirk W; Xie, Jingping; Daniel, Deborah; Ulrich-Lewis, Justin Theophilus; Zhang, Lixin

    2014-07-01

    Lipooligosaccharide configurations were predicted in nontypeable Haemophilus influenzae isolates based on the presence of seven oligosaccharide extension-initiating genes (or alleles). Predicted configurations with 2 to 3 oligosaccharide extensions were more prevalent among middle ear than throat strains. In addition, strains with these configurations averaged higher levels of serum resistance than strains with other configurations.

  18. Two variants among Haemophilus influenzae serotype b strains with distinct bcs4, hcsA and hcsB genes display differences in expression of the polysaccharide capsule

    Directory of Open Access Journals (Sweden)

    Burger Marina

    2008-02-01

    Full Text Available Abstract Background Despite nearly complete vaccine coverage, a small number of fully vaccinated children in the Netherlands have experienced invasive disease caused by Haemophilus influenzae serotype b (Hib. This increase started in 2002, nine years after the introduction of nationwide vaccination in the Netherlands. The capsular polysaccharide of Hib is used as a conjugate vaccine to protect against Hib disease. To evaluate the possible rise of escape variants, explaining the increased number of vaccine failures we analyzed the composition of the capsular genes and the expressed polysaccharide of Dutch Hib strains collected before and after the introduction of Hib vaccination. Results The DNA sequences of the complete capsular gene clusters of 9 Dutch Hib strains were assessed and two variants, designated type I and type II were found. The two variants displayed considerable sequence divergence in the hcsA and hcsB genes, involved in transport of capsular polysaccharide to the cell surface. Application of hcsA type specific PCRs on 670 Hib strains collected from Dutch patients with invasive Hib disease showed that 5% of the strains collected before 1996 were type II. No endogenous type II Hib strains were isolated after 1995 and all type II strains were isolated from 0–4 year old, non-vaccinated children only. Analysis of a worldwide collection of Hib strains from the pre-vaccination era revealed considerable geographic differences in the distribution of the type I and type II strains with up to 73% of type II strains in the USA. NMR analysis of type I and type II capsule polysaccharides did not reveal structural differences. However, type I strains were shown to produce twice as much surface bound capsular polysaccharide. Conclusion Type II strains were only isolated during the pre-vaccination era from young, non-vaccinated individuals and displayed a lower expression of capsular polysaccharide than type I strains. The higher polysaccharide

  19. Culture and PCR detection of Haemophilus influenzae and Haemophilus haemolyticus in Australian Indigenous children with bronchiectasis.

    Science.gov (United States)

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

    2012-07-01

    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.

  20. A comparative study of preservation and storage of Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Olga C Aulet de Saab

    2001-05-01

    Full Text Available The aim of this study was to compare the efficacy of conservation by freezing the strains of Haemophilus influenzae at -20ºC and -70ºC. Skim milk supplemented with glucose, yeast extract and glycerol allowed highest viability of H. influenzae both at -20ºC and -70ºC from the media analyzed. Trypticase soy broth and brain heart infusion broth supplemented with glycerol, allowed excellent recovery. Use of cotton swaps as supporting material, with or without addition of cryoprotective agents, did not modify H. influenzae viability after six months of storage. Concentration of the initial inoculum positively affected viability when stored at -20ºC. Initial concentration did not influence survival after storage at -70ºC. Thawing at room temperature should not exceed 3 h as to get highest survival percentage.

  1. Transformation of Haemophilus influenzae by plasmid RSF0885

    Energy Technology Data Exchange (ETDEWEB)

    Notani, N.K.; Setlow, J.K.; McCarthy, D.; Clayton, N.L.

    1981-12-01

    Plasmid RSF0885, which conferred ampicillin resistance, transformed competent Haemophilus influenzae cells with low efficiency (maximun, less than 0.01%). As judged by competition experiments and uptake of radioactivity, plasmid RSF0885 deoxyribonucleic acid was taken up into competent H. influenzae cells several orders of magnitude less efficiently than H. influenzae chromosomal deoxyribonucleic acid. Plasmid RSF0885 transformed cells with even lower efficiency than could be accounted for by the low uptake. Transformation was not affected by rec-1 and rec-2 mutations in the recipient, and strains cured of the plasmid did not show increased transformation. Plasmid molecules cut once with a restriction enzyme that made blunt ends did not transform. Transformation was favored by the closed circular form of the plasmid.

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

    Science.gov (United States)

    Murphy, Timothy F

    2015-05-01

    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.

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

    Science.gov (United States)

    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.

  4. Haemophilus influenzae strains possess variations in the global transcriptional profile in response to oxygen levels and this influences sensitivity to environmental stresses.

    Science.gov (United States)

    Jiang, Donald; Tikhomirova, Alexandra; Kidd, Stephen P

    2016-01-01

    An alcohol dehydrogenase, AdhC, is required for Haemophilus influenzae Rd KW20 growth with high oxygen. AdhC protects against both exogenous and metabolically generated, endogenous reactive aldehydes. However, adhC in the strain 86-028NP is a pseudogene. Unlike the Rd KW20 adhC mutant, 86-028NP does grow with high oxygen. This suggests the differences between Rd KW20 and 86-028NP include broader pathways, such as for the maintenance of redox and metabolism that avoids the toxicity related to oxygen. We hypothesized that these differences affect their resistance to relevant toxic chemicals, including reactive aldehydes. Across a range of oxygen concentrations, despite the growth profiles of Rd KW20 and 86-028NP being similar, there was a significant variation in their sensitivity to reactive aldehydes. 86-028NP is more sensitive to methylglyoxal, formaldehyde and glycolaldehyde under high oxygen than low oxygen as well as compared to Rd KW20. Also, as oxygen levels changed the whole genome gene expression profiles of Rd KW20 and 86-028NP revealed distinctions in their transcriptomes (the iron, FNR and ArcAB regulons). These were indicative of a difference in their intracellular redox properties and we show it is this that underpins their survival against reactive aldehydes.

  5. Crystal Structure of a Complex of Surfactant Protein D (SP-D) and Haemophilus influenzae Lipopolysaccharide Reveals Shielding of Core Structures in SP-D-Resistant Strains.

    Science.gov (United States)

    Clark, Howard W; Mackay, Rose-Marie; Deadman, Mary E; Hood, Derek W; Madsen, Jens; Moxon, E Richard; Townsend, J Paul; Reid, Kenneth B M; Ahmed, Abdul; Shaw, Amy J; Greenhough, Trevor J; Shrive, Annette K

    2016-05-01

    The carbohydrate recognition domains (CRDs) of lung collectin surfactant protein D (SP-D) recognize sugar patterns on the surface of lung pathogens and promote phagocytosis. Using Haemophilus influenzae Eagan strains expressing well-characterized lipopolysaccharide (LPS) surface structures of various levels of complexity, we show that bacterial recognition and binding by SP-D is inversely related to LPS chain extent and complexity. The crystal structure of a biologically active recombinant trimeric SP-D CRD complexed with a delipidated Eagan 4A LPS suggests that efficient LPS recognition by SP-D requires multiple binding interactions utilizing the three major ligand-binding determinants in the SP-D binding pocket, with Ca-dependent binding of inner-core heptose accompanied by interaction of anhydro-Kdo (4,7-anhydro-3-deoxy-d-manno-oct-2-ulosonic acid) with Arg343 and Asp325. Combined with enzyme-linked immunosorbent assays (ELISAs) and fluorescence-activated cell sorter (FACS) binding analyses, our results show that extended LPS structures previously thought to be targets for collectins are important in shielding the more vulnerable sites in the LPS core, revealing a mechanism by which pathogens with complex LPS extensions efficiently evade a first-line mucosal innate immune defense. The structure also reveals for the first time the dominant form of anhydro-Kdo.

  6. Comparative analysis of Haemophilus influenzae hifA (pilin) genes.

    Science.gov (United States)

    Clemans, D L; Marrs, C F; Patel, M; Duncan, M; Gilsdorf, J R

    1998-02-01

    Adherence of Haemophilus influenzae to epithelial cells plays a central role in colonization and is the first step in infection with this organism. Pili, which are large polymorphic surface proteins, have been shown to mediate the binding of H. influenzae to cells of the human respiratory tract. Earlier experiments have demonstrated that the major epitopes of H. influenzae pili are highly conformational and immunologically heterogenous; their subunit pilins are, however, immunologically homogenous. To define the extent of structural variation in pilins, which polymerize to form pili, the pilin genes (hifA) of 26 type a to f and 16 nontypeable strains of H. influenzae were amplified by PCR and subjected to restriction fragment length polymorphism (RFLP) analysis with AluI and RsaI. Six different RFLP patterns were identified. Four further RFLP patterns were identified from published hifA sequences from five nontypeable H. influenzae strains. Two patterns contained only nontypeable isolates; one of these contained H. influenzae biotype aegyptius strains F3031 and F3037. Another pattern contained predominantly H. influenzae type f strains. All other patterns were displayed by a variety of capsular and noncapsular types. Sequence analysis of selected hifA genes confirmed the 10 RFLP patterns and showed strong identity among representatives displaying the same RFLP patterns. In addition, the immunologic reactivity of pili with antipilus antisera correlated with the groupings of strains based on hifA RFLP patterns. Those strains that show greater reactivity with antiserum directed against H. influenzae type b strain M43 pili tend to fall into one RFLP pattern (pattern 3); while those strains that show equal or greater reactivity with antiserum directed against H. influenzae type b strain Eagan pili tend to fall in a different RFLP pattern (pattern 1). Sequence analysis of representative HifA pilins from typeable and nontypeable H. influenzae identified several highly

  7. [Pathogenesis of beta-lactam-resistant Haemophilus influenzae isolated from sputum].

    Science.gov (United States)

    Watanuki, Yuji; Odagiri, Shigeki; Takahashi, Hiroshi; Ogura, Takashi; Tomioka, Toshiaki

    2004-10-01

    Haemophlus influenzae persists in the respiratory tract and sometimes causes respiratory tract infections. To evaluate the pathogenesis of beta-lactam-resistant Haemophilus influenzae, we classified 193 Haemophilus influenzae strains isolated from sputum of patients with respiratory tract disease in 24 beta-lactamase positive (BLP) strains, 65 beta-lactamase negative ampicillin resistant (BLNAR) strains and 104 beta-lactamase negative ampicillin sensitive (BLNAS) strains and reviewed the pathogenesis of the strains. The pathogenesis of the strains was evaluated as definite pathogen, presumptive pathogen, colonization and contamination. It was judged to be the definite pathogen that many bacteria isolated from high quality sputum of the patients with respiratory tract infections. Presumptive pathogen was considered to be the bacteria provided from the patient with respiratory infections when the quality of the sputum or quantity of bacteria did not satisfy superscription basis. We considered the bacteria to be colonization or contamination isolated from patients without infections. The breakdown of definite pathogen/presumptive pathogen/colonization/contamination in each by groups was BLP (8/4/8/4), BLNAR (26/14/15/10), BLNAS (36/20/31/17). The ratio of definite or presumptive pathogen was 50% in BLP, 62% in BLNAR and 54% in BLNAS and the significant difference was not recognized in these. Pathogenesis of beta-lactam-resistant Haemophilus influenzae is estimated to be equal with beta-lactam-sensitive Haemophilus influenzae.

  8. [Haemophilus influenzae type B meningitis: typical and atypical presentation].

    Science.gov (United States)

    Sánchez, J M; Zurro, F J; Ferreiro, D; Llana, R; Uría, D F

    1998-02-01

    We present 2 cases of Haemophilus influenzae meningitis. The first is a patient with atypical simptomatology: abdominal pain, fever and two days later pain in the back of his legs. Abdominal pathology was not found. The cerebrospinal fluid (CSF) showed polymorphonuclear cells, hyperproteinorachia and lowered glucose. CSF culture revealed Haemophilus influenzae, blood culture was sterile. The second had suffered surgery at maxilar and ethmoid sinuses four years before, and unknown germ meningitis 6 months before. Haemophilus influenzae was isolated from CSF cultures and CSF rhinorrhea was detected by isotopic cisternography.

  9. PBP profiles of Haemophilus influenzae, H. aegyptius, and the H. influenzae biogroup aegyptius associated with Brazilian Purpuric Fever.

    Science.gov (United States)

    Mendelman, P M; Chaffin, D O

    1989-01-01

    We questioned if PBP analysis could differentiate strains of Haemophilus influenzae, H. aegyptius, and H. influenzae biogroup aegyptius associated with Brazilian Purpuric Fever. A relatively homogeneous PBP pattern was observed for all strains. The amount of penicillin bound to PBP 5 appeared to separate H. influenzae and H. aegyptius isolates, whereas PBP 5 of those strains associated with Brazilian Purpuric Fever bound an intermediate amount. We conclude that based on PBP profiles, the strains tested appear to be difficult to separate taxonomically and may represent a common species.

  10. First Complete Genome Sequence of Haemophilus influenzae Serotype a

    Science.gov (United States)

    Hayden, Kristy

    2017-01-01

    ABSTRACT Haemophilus influenzae is an important human pathogen that primarily infects small children. In recent years, H. influenzae serotype a has emerged as a significant cause of invasive disease among indigenous populations. Here, we present the first complete whole-genome sequence of H. influenzae serotype a. PMID:28104664

  11. Variation in metabolic enzyme activity of persistent Haemophilus influenzae in respiratory tracts of patients with cystic fibrosis.

    OpenAIRE

    Möller, L V; Grasselier, H; Dankert, J.; van Alphen, L

    1996-01-01

    Haemophilus influenzae organisms were isolated from sputum specimens prospectively collected from 40 patients with cystic fibrosis during 2 years to study variations in the metabolic enzyme activities of persistent H. influenzae strains as determined by biotyping. In total, 97 distinct H. influenzae strains without variations in their major outer membrane protein (MOMP) patterns and 73 MOMP variants derived from 30 of these distinct strains were obtained. Twelve distinct strains and 42 MOMP v...

  12. TEM-1-encoding small plasmids impose dissimilar fitness costs on Haemophilus influenzae and Haemophilus parainfluenzae.

    Science.gov (United States)

    Søndergaard, Annette; Lund, Marianne; Nørskov-Lauritsen, Niels

    2015-12-01

    Only two beta-lactamases, TEM-1 and ROB-1, have been observed in Haemophilus influenzae, while four different TEM but no ROB enzymes have been found in Haemophilus parainfluenzae. In order to investigate the mechanisms behind the dissemination of small beta-lactamase-encoding plasmids in H. influenzae and H. parainfluenzae, we assessed the fitness cost of three TEM-1- (pPN223, pA1209, pA1606), one TEM-15- (pSF3) and one ROB-1-bearing (pB1000) plasmid when expressed in either bacterial species. All plasmids were stable in H. influenzae and H. parainfluenzae except pB1000, which showed on average (sample mean) 76% curing in H. parainfluenzae after 5  days of subculture. Competition assays between isogenic strains with and without plasmid showed no competitive disadvantage of pPN223 and pA1606 in H. influenzae, or of pA1209 in H. parainfluenzae. In contrast, pSF3 and pB1000 were associated with significant competitive disadvantages in both species. Some of the competitive disadvantages may be related to differences in plasmid copy number and mRNA expression of the beta-lactamase genes, as revealed by quantitative PCR analysis. In conclusion, plasmids encoding TEM beta-lactamases isolated from H. influenzae and H. parainfluenzae can be stably transferred between species. The fast curing of pB1000 in H. parainfluenzae observed in this study correlates to the fact that ROB-1 has never been reported for this species. TEM-1-encoding plasmids are associated with the lowest level of fitness cost, but different TEM-1 plasmids confer different levels of fitness cost on the two hosts.

  13. Metabolic versatility in Haemophilus influenzae: a metabolomic and genomic analysis

    Directory of Open Access Journals (Sweden)

    Dk Seti Maimonah Pg eOthman

    2014-03-01

    Full Text Available Haemophilus influenzae is a host adapted human pathogen known to contribute to a variety of acute and chronic diseases of the upper and lower respiratory tract as well as the middle ear. At the sites of infection as well as during growth as a commensal the environmental conditions encountered by H. influenzae will vary significantly, especially in terms of oxygen availability, however, the mechanisms by which the bacteria can adapt their metabolism to cope with such changes have not been studied in detail. Using targeted metabolomics the spectrum of metabolites produced during growth of H. influenzae on glucose in RPMI-based medium was found to change from acetate as the main product during aerobic growth to formate as the major product during anaerobic growth. This is likely caused by a switch in the major pyruvate degrading route. Neither lactate nor succinate or fumarate were major products of H. influenzae growth under any condition studied Gene expression studies and enzyme activity data revealed that despite an identical genetic makeup and very similar metabolite production profiles, H. influenzae strain Rd appeared to favour glucose degradation via the PPP, while strain 2019, a clinical isolate, showed higher expression of enzymes involved in glycolysis. Components of the respiratory chain were most highly expressed during microaerophilic and anaerobic growth in both strains, but again clear differences existed in the expression of genes associated e.g. with NADH oxidation, nitrate and nitrite reduction in the two strains studied.Together our results indicate that H. influenzae uses a specialized type of metabolism that could be termed ‘respiration assisted fermentation’ where the respiratory chain likely serves to alleviate redox imbalances caused by incomplete glucose oxidation, and at the same time provides a means of converting a variety of compounds including nitrite and nitrate that arise as part of the host defence mechanisms.

  14. Pneumonia due to Haemophilus influenzae (H. aegyptius) biotype 3.

    Science.gov (United States)

    Marraro, R V; McCleskey, F K; Mitchell, J L

    1977-08-01

    Haemophilus influenzae (H. aegyptius) biotype 3 was isolated from eye, nasopharyngeal, and sputum cultures of a 23-month-old male and from sputum and transtracheal aspirate cultures of his 39-year-old mother, both with diffuse bronchopneumonia.

  15. Duplication of pilus gene complexes of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Read, T D; Dowdell, M; Satola, S W; Farley, M M

    1996-11-01

    Brazilian purpuric fever (BPF) is a recently described pediatric septicemia caused by a strain of Haemophilus influenzae biogroup aegyptius. The pilus specified by this bacterium may be important in BPF pathogenesis, enhancing attachment to host tissue. Here, we report the cloning of two haf (for H. influenzae biogroup aegyptius fimbriae) gene clusters from a cosmid library of strain F3031. We sequenced a 6.8-kb segment of the haf1 cluster and identified five genes (hafA to hafE). The predicted protein products, HafA to HafD, are 72, 95, 98, and 90% similar, respectively, to HifA to HifD of the closely related H. influenzae type b pilus. Strikingly, the putative pilus adhesion, HifE, shares only 44% identity with HafE, suggesting that the proteins may differ in receptor specificity. Insertion of a mini-gammadelta transposon in the hafE gene eliminated hemadsorption. The nucleotide sequences of the haf1 and haf2 clusters are more than 99% identical. Using the recently published sequence of the H. influenzae Rd genome, we determined that the haf1 complex lies at a unique position in the chromosome between the pmbA gene and a hypothetical open reading frame, HI1153. The location of the haf2 cluster, inserted between the purE and pepN genes, is analogous to the hif genes on H. influenzae type b. BPF fimbrial phase switching appears to involve slip-strand mispairing of repeated dinucleotides in the pilus promoter. The BPF-associated H. influenzae biogroup aegyptius pilus system generally resembles other H. influenzae, but the possession of a second fimbrial gene cluster, which appears to have arisen by a recent duplication event, and the novel sequence of the HafE adhesin may be significant in the unusual pathogenesis of BPF.

  16. Long-term mortality in children diagnosed with Haemophilus influenzae meningitis: a Danish nationwide cohort study

    DEFF Research Database (Denmark)

    Roed, Casper; Engsig, Frederik Neess; Omland, Lars Haukali;

    2011-01-01

    The long-term mortality in children diagnosed with Haemophilus influenzae meningitis is poorly documented.......The long-term mortality in children diagnosed with Haemophilus influenzae meningitis is poorly documented....

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

    Science.gov (United States)

    ... taken in its entirety from the CDC Hib (Haemophilus Influenzae Type b) Vaccine Information Statement (VIS): www.cdc. ... statements/hib.pdf . CDC review information for Hib (Haemophilus Influenzae Type b) VIS: Page last reviewed: April 2, ...

  18. Multicentre in-vitro evaluation of the susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin

    NARCIS (Netherlands)

    HoogkampKorstanje, JAA; DirksGo, SIS; Kabel, P; Manson, WL; Stobberingh, EE; Vreede, RW; Davies, BI

    1997-01-01

    Seven laboratories, including a reference laboratory, tested the susceptibility of Moraxella catarrhalis, Streptococcus pneumoniae and Haemophilus influenzae strains to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin with the Etest. A total of 976 strains were collected. The results wit

  19. Multicentre in-vitro evaluation of the susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin

    NARCIS (Netherlands)

    HoogkampKorstanje, JAA; DirksGo, SIS; Kabel, P; Manson, WL; Stobberingh, EE; Vreede, RW; Davies, BI

    Seven laboratories, including a reference laboratory, tested the susceptibility of Moraxella catarrhalis, Streptococcus pneumoniae and Haemophilus influenzae strains to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin with the Etest. A total of 976 strains were collected. The results

  20. Multicentre in-vitro evaluation of the susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin

    NARCIS (Netherlands)

    HoogkampKorstanje, JAA; DirksGo, SIS; Kabel, P; Manson, WL; Stobberingh, EE; Vreede, RW; Davies, BI

    1997-01-01

    Seven laboratories, including a reference laboratory, tested the susceptibility of Moraxella catarrhalis, Streptococcus pneumoniae and Haemophilus influenzae strains to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin with the Etest. A total of 976 strains were collected. The results wit

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  3. Haemophilus influenzae infections in adults: a pathogen in search of respect.

    Science.gov (United States)

    Strausbaugh, L J

    1997-02-01

    Despite the success of Haemophilus influenzae type b vaccines in preventing bacterial disease in children, H influenzae remains a common pathogen in adult patients in the United States and Europe. At least half of invasive H influenzae infections are caused by nontypable strains. The spectrum of diseases includes sinusitis, pneumonia, otitis media, epiglotitis, and meningitis. An etiologic diagnosis is most reliably established by positive cultures from a normally sterile site. Although resistance to ampicillin and amoxicillin has steadily increased in clinical H influenzae isolates during the past two decades, a variety of other antimicrobial agents are available for the treatment of infections caused by this bacterium.

  4. Inflammatory response of Haemophilus influenzae biotype aegyptius causing Brazilian Purpuric Fever

    OpenAIRE

    Gisele Cristiane Gentile Cury; Rafaella Fabiana Carneiro Pereira; Luciana Maria de Hollanda; Marcelo Lancellotti

    2015-01-01

    The Brazilian Purpuric Fever (BPF) is a systemic disease with many clinical features of meningococcal sepsis and is usually preceded by purulent conjunctivitis. The illness is caused by Haemophilus influenza biogroup aegyptius, which was associated exclusively with conjunctivitis. In this work construction of the las gene, hypothetically responsible for this virulence, were fusioned with ermAM cassette in Neisseria meningitidis virulent strains and had its DNA transfer to non BPF H. influenza...

  5. The in-vitro activity of pristinamycin against Haemophilus influenzae and Neisseria meningitidis.

    Science.gov (United States)

    Lafaix, C; Bouvet, E; Dublanchet, A; Dabernat, H; Carrere, C; Picq, J J; Etienne, J

    1985-07-01

    The in-vitro activity of erythromycin, oleandomycin, spiramycin, josamycin and pristinamycin was tested by a plate-dilution method against strains of Haemophilus influenzae and Neisseria meningitidis. Pristinamycin was the most active product tested with minimal inhibitory concentrations (MIC) ranging between 0.5 and 4 mg/l for H. influenzae (modal value 1 mg/l) and between 0.03 and 0.12 mg/l for N. meningitidis (modal value 0.06 mg/l).

  6. To tilfaelde af invasive infektioner med Haemophilus influenzae type f

    DEFF Research Database (Denmark)

    Nielsen, Jette Dettmann; Lind, Jens Wentzel; Bruun, Britta;

    2009-01-01

    Two cases of invasive Haemophilus influenzae type f infection are presented: a three-week-old boy with meningitis and a 62-year-old woman with arthritis and bacteremia. Since 1993 vaccination against H. influenzae type b (Hib) has been offered to Danish children. The result has been a remarkable...

  7. [Two cases of invasive Haemophilus influenzae type f infection

    DEFF Research Database (Denmark)

    Nielsen, J.D.; Lind, J.W.; Bruun, B.

    2009-01-01

    Two cases of invasive Haemophilus influenzae type f infection are presented: a three-week-old boy with meningitis and a 62-year-old woman with arthritis and bacteremia. Since 1993 vaccination against H. influenzae type b (Hib) has been offered to Danish children. The result has been a remarkable...

  8. To tilfaelde af invasive infektioner med Haemophilus influenzae type f

    DEFF Research Database (Denmark)

    Nielsen, Jette Dettmann; Lind, Jens; Bruun, Brita

    2009-01-01

    Two cases of invasive Haemophilus influenzae type f infection are presented: a three-week-old boy with meningitis and a 62-year-old woman with arthritis and bacteremia. Since 1993 vaccination against H. influenzae type b (Hib) has been offered to Danish children. The result has been a remarkable...

  9. [Two cases of invasive Haemophilus influenzae type f infection

    DEFF Research Database (Denmark)

    Nielsen, J.D.; Lind, J.W.; Bruun, B.

    2009-01-01

    Two cases of invasive Haemophilus influenzae type f infection are presented: a three-week-old boy with meningitis and a 62-year-old woman with arthritis and bacteremia. Since 1993 vaccination against H. influenzae type b (Hib) has been offered to Danish children. The result has been a remarkable...

  10. Plasmid containing a DNA ligase gene from Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, D.; Griffin, K.; Setlow, J.K.

    1984-05-01

    A ligase gene from Haemophilus influenzae was cloned into the shuttle vector pDM2. Although the plasmid did not affect X-ray sensitivity, it caused an increase in UV sensitivity of the wild-type but not excision-defective H. influenzae and a decrease in UV sensitivity of the rec-1 mutant. 14 references, 2 figures.

  11. Plasmid cloning vehicle for Haemophilus influenzae and Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, D.; Clayton, N.L.; Setlow, J.K.

    1982-09-01

    A new plasmid cloning vehicle (pDM2) was used to introduce a library of Haemophilus influenzae chromosomal fragments into H. influenzae. Transformants of the higly recombination-defective rec-1 mutant were more likely to contain exclusively recombinant plasmids after exposure to ligated DNA mixtures than was the wild type. pDM2 could replicate in Escherichia coli K-12.

  12. Analysis of Haemophilus influenzae serotype f isolated from three Japanese children with invasive H. influenzae infection.

    Science.gov (United States)

    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.

  13. Utility of antimicrobial susceptibility testing of multiple Haemophilus influenzae isolates from throat swabs of children with adenoid hypertrophy.

    Science.gov (United States)

    Antos-Bielska, Małgorzata; Lau-Dworak, Magdalena; Olszewska-Sosińska, Olga; Zielnik-Jurkiewicz, Beata; Trafny, Elżbieta A

    2014-07-01

    Eleven out of 40 children with adenoiditis were colonized with multiple genotypes of Haemophilus influenzae. Heterogeneous antibiotic susceptibility to ampicillin and cotrimoxazole was observed in 6 children. A multiple-colony methodology may potentially help to find the resistant strains of H. influenzae in patients who do not respond to the antibiotic treatment.

  14. Construction of a novel shuttle vector for use in Haemophilus influenzae and H. parainfluenzae

    Science.gov (United States)

    Robinson, Esther; Juhas, Mario; Hood, Derek; Crook, Derrick

    2010-01-01

    Haemophilus influenzae is an important human pathogen. A number of complete genome sequences of various haemophili are available; however, functional studies have been limited by the lack of an effective shuttle vector which functions in all strains. Here, we have constructed a shuttle vector, pEJ6, which transfers genes between Escherichia coli and H. influenzae and H. parainfluenzae. The vector contains an origin of replication from pLS88 which is functional in E. coli and H. influenzae. In addition it contains an RP4 mobilisation region. The vector can be introduced by electroporation and conjugation into capsulate and non-typeable H. influenzae and is functional for allelic replacement and mutant complementation. The vector will be useful for investigating gene function in Haemophilus spp. PMID:20849885

  15. Activity of ciprofloxacin and azithromycin on biofilms produced in vitro by Haemophilus influenzae

    Institute of Scientific and Technical Information of China (English)

    WANG Dong; WANG Ying; LIU You-ning

    2009-01-01

    Background It is recognized that Haemophilus influenzae isolated from patients with otitis media forms biofilms both in vitro and in vivo, suggesting that biofilm formation in vivo might play an important role in the pathogenesis and chronicity of otitis media, but the effect of antibiotics on biofilm has not been well studied. We investigated the impact of ciprofloxacin and azithromycin on bacterial biofilms formed by Haemophilus influenzae in vitro in this study.Methods Eleven strains of Haemophilus influenzae were isolated from sputum specimens collected from patients with acute exacerbation of chronic obstructive pulmonary diseases. Formation of bacterial biofilm was examined by crystal violet assay and a scanning electron microscope. Alterations of biofilms were measured under varying concentrations of azithromycin and ciprofloxacin.Results Striking differences were observed among strains with regard to the ability to form biofilm. Typical membrane-like structure formed by bacterial cells and extracellular matrix was detected. Initial biofilm synthesis was inhibited by azithromycin and ciprofloxacin at concentrations higher than two-fold minimal inhibitory concentration.Disruption of mature biofilms could be achieved at relatively higher concentration, and ciprofloxacin displayed more powerful activity.Conclusions Haemophilus influenzae is capable of forming biofilm in vitro. Sufficient dosage might control early formation of biofilms. Ciprofloxacin exerts better effects on breakdown of biofilm than azithromycin at conventional concentration in clinics.

  16. Is Haemophilus influenzae better satellite for Enterococcus faecalis?

    Directory of Open Access Journals (Sweden)

    Firat Zafer Mengeloglu

    2013-09-01

    Full Text Available Background — Haemophilus influenzae can grow on blood agar media with Staphylococcus aureus which can provide factor V as it is called “Satellite phenomenon”. Objectives — In this study we tested and compared three different beta-haemolytic genus including three Staphylococcus aureus, three coagulase-negative staphylococci, and two Enterococcus faecalis strains in order to determine an alternative microorganism to be used for satellite test to identify H. influenzae conventionally. Materials and Methods — We used suspensions of H. influenzae in two different tribudities as 0.5 and 4 McFarland for each strain. Five totally-blinded reviewers examined the test results and scored both the colony sizes of H. influenzae and the diameter of the growth-zone. The sum of the scores for the colony sizes and the growth-zones were determined as “total diagnostic score” (TDS as being between 0-6 points for each test. Results — A total of 320 test scores were analysed. The mean TDS of E. faecalis group was significantly higher than the other groups (p<0.001. In the S. aureus group, 23 (19.2% tests had 0 points as TDS; but in enterococci group no isolates had lower scores than 3 points. In enterococci group, the rate of isolates which had 5 or 6 points was 77.5% (62/80; but in S. aureus group no isolate had higher than 4 points. Conclusions — Our study shows that using a beta-haemolytic E. faecalis strain will provide significantly more accurate results and will significantly reduce false-negative results for satellite test instead of S. aureus, which is particularly proposed to be used.

  17. Haemophilus influenzae: a forgotten cause of neonatal sepsis?

    Science.gov (United States)

    Dobbelaere, A; Jeannin, P; Bovyn, T; Ide, L

    2015-06-01

    Due to the introduction of the conjugate vaccine against serotype b, neonatal sepsis caused by Haemophilus influenzae became very rare. There is little data in Belgium concerning the prevalence of H. influenzae early onset neonatal sepsis and articles about neonatal sepsis and H. influenzae published in the last decade are scarce. We report two invasive infections with a non-typeable H. influenzae. These cases show that neonatal sepsis caused by non-typeable H. influenzae may be underestimated and we believe that there is need for a better registration of this kind of infection.

  18. Prophage induction and inactivation by uv light. [Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Barnhart, B.J.; Cox, S.H.; Jett, J.H.

    1976-06-01

    Analysis of the induction curves for uv light-irradiated Haemophilus influenzae lysogens and the distribution of pyrimidine dimers in a repair-deficient lysogen suggests that one dimer per prophage-size segment of the host bacterial chromosome is necessary as a preinduction event. The close correlations obtained prompted a renewed consideration of the possibility that direct prophage induction occurs when one dimer is stabilized within the prophage genome. The host excision-repair system apparently functions to reduce the probability of stabilizing within the prophage those dimers that are necessary for induction and inactivation. The presence of the inducible defective prophage in strain Rd depresses the inducibility of prophage HP1c1.

  19. Research on PCR determining of type b Haemophilus influenzae strains and immunogenicity of polysaccharide conjugates%几株b型流感嗜血杆菌多糖结合物的免疫原性检定

    Institute of Scientific and Technical Information of China (English)

    袁玉兰; 郭京蓉; 周继唯; 高华

    2012-01-01

    Objective To determine Haemophilus influenzae type b strains in molecular level using PCR,and to study the immunogenicity of capsular polysaccharide conjugates in mice.Methods Extracting genomes using bacterial DNA extract kit from Hoemophilus influenzae type b strains,and PCR for determining the strains through serotyping-specific and capsular genotyping primers respectively.Various capsular polysaccharides conjugated TT respectively,and the conjugates were administered subcutaneously to mice through dilution.After vaccination with two doses,blood samples were collected for the detection of antibody levels to polyribosylribitol phosphate ( PRP),the capsular polysaccharide of Hib.Results All five Haemophilus influenzae type b strains contain type-specific(482 bp) and capsular type (343 bp)DNA fragment through PCR detecting.The DNA fragments were sequenced.BLAST show that these sequences are 100% homology comparing the above strains respectively,and are 99% and 100% homology comparing the GenBank X78559.1 and M19995.1 respectively.The immunogenicity of mice from various capsular polysaccharide conjugates (PRP-TT) was not significantly different by ELISA detecting.Conclusion Through PCR,Haemophilus influenzae type b strain can be determined in molecular level.The immunogenicity of mice from purified capsular polysaccharide conjugates was not different.The study provides a detection means for the features and heredity stability of Haemophilus influenzae type b strain and reference data for the immunogenicity of different polysaccharide conjugates in vaccine research and development and production.%目的 从分子水平检定b型流感嗜血杆菌,研究不同菌株荚膜多糖结合物的免疫原性.方法 提取基因组,通过型特异和荚膜型基因特异引物,利用PCR检定b型流感嗜血杆菌;不同纯化多糖分别与破伤风类毒素(TT)进行耦联结合,结合物原液经稀释免疫小鼠,通过两针免疫,采血进行免疫效力测定.

  20. 249株流感嗜血杆菌的分离与耐药性分析%Analysis on Isolation and Antibiotic Resistance of 249 Strains of Haemophilus influenzae

    Institute of Scientific and Technical Information of China (English)

    曹敏晖; 曹友德; 李浩; 蔡瑞云

    2011-01-01

    目的 了解流感嗜血杆菌(Hi)的检出状况与耐药情况,指导临床合理用药.方法 统计分析2007-2010年我院Hi的分离与耐药情况.结果 在1052份痰及咽拭子标本中分离出Hi 210株,在242份胆汁标本中分离出Hi 16株,在203份胸腹水标本中分离出Hi 12株,在163份眼、耳拭子标本中分离出Hi 11株.体外药敏结果显示Hi对复方磺胺甲恶哇耐药性最高为63.5%,氨苄西林次之为46.2%,而对阿莫西林/棒酸、利福平、头孢呋辛、头孢噻肟、亚氨培南敏感,耐药率≤2.0%.结论 Hi在呼吸道标本中的检出率最高,眼、耳拭子标本中次之,在胆汁、胸腹水中亦有检出.建议眼、耳拭子及胆汁、胸腹水标本作细菌培养时也应同时接种哥伦比亚血平板(COS)、淋球菌选择性平板(VCA)及嗜血杆菌选择性平板(HAE),Hi感染的治疗应首选复方阿莫西林、头孢二代或三代类抗生素.%Objective To investigate the isolation rate and antibiotic resistance rate of Haemophilus influenzae, and to guide the rational use of antibiotic therapy in clinical practice. Methods The data about the isolation rate and antibiotic resistance rate of Haemophilus influenzae from 2007 to 2010 were analyzed with SPSS11.0 statistical software. Results Totally 210 strains of Haemophilus influenzae were isolated from 1,052 specimens of sputum and pharyngeal secretion, 16 strains isolated from 242 bile specimens, 12 strains isolated from 203 hydrothoraxs specimens, and 11 strains isolated from 163 specimens of eye or ear secretion. In vitro drug- sensitivity test showed that the resistance rate of Haemophilus influenzae to trimethoprime sulfanomicles was the highest (63.5%), followed by ampicillin (46.2%). But the resistance rates to amoxicillin/clavalanic acid, rifampicine, cefuroxime, cefotaxime and imipenem were very low (≤2.0%). Conclusions Heamophilus influenzae could be isolated from the secretions of respiratory track, eye, ear, bile

  1. Epidemiology of Haemophilus influenzae type b invasive disease in Wales.

    Science.gov (United States)

    Howard, A J; Dunkin, K T; Musser, J M; Palmer, S R

    1991-01-01

    OBJECTIVE--To investigate the epidemiology of invasive disease due to Haemophilus influenzae type b, the clones responsible, and the antibiotic resistance of the isolates. DESIGN--Prospective population based analysis of clinical and epidemiological data collected for Gwynedd during 1980-90 and in the whole of Wales during 1988-90. SETTING--19 hospitals in Wales; all medical microbiology laboratories in Wales participated. PATIENTS--82 patients with confirmed invasive infections caused by H influenzae type b in Gwynedd during 1980-90 and 207 in Wales during 1988-90. MAIN OUTCOME MEASURES--Clinical and epidemiological measures; analysis of the clonal types of the isolates based on the electrophoretic mobilities of 17 metabolic enzymes; and antibiotic resistance. RESULTS--The annual incidence of H influenzae type b infections in Gwynedd was 3.2 cases/100,000 and in Wales was 2.5 cases/100,000. Most cases occurred in children aged under 5 years, the highest annual incidence being in those aged under 1 (84.6/100,000 and 56.9/100,000 in Wales). The cumulative risk of acquiring H influenzae type b disease by the fifth birthday was one in 456 in Gwynedd and one in 578 in Wales. Fifteen per cent of cases in Gwynedd and 7% of those in Wales occurred in adults. Predominant clinical conditions were meningitis in children and pneumonia in adults. In Gwynedd 2/70 (3%) children and 5/12 (42%) adults died. Long term neurological sequelae occurred in 8% (4/48) of children who survived haemophilus meningitis. Children presenting with infection were usually the youngest members of their family. No secondary household cases were identified. 100 of 128 (78%) strains were of a single clone, electrophoretic type 12.5, and 4/207 (1.9%) isolates from Wales were resistant to both ampicillin and chloramphenicol. CONCLUSIONS--The annual rate of infection in children aged under 5 in four Welsh counties was 12-44% higher than that previously published for the United Kingdom. The study

  2. Antigenic heterogeneity of immunoglobulin A1 proteases from encapsulated and non-encapsulated Haemophilus influenzae.

    Science.gov (United States)

    Kilian, M; Thomsen, B

    1983-10-01

    Indirect evidence suggests that immunoglobulin A1 (IgA1) proteases may be factors in the pathogenesis of certain infectious diseases, including meningitis, gonorrhoea, and destructive periodontitis. Bacterial IgA1 proteases are therefore potential candidates as vaccines. In this study, IgA1 proteases from 166 clinical isolates and reference strains of Haemophilus influenzae and Haemophilus aegyptius were compared with regard to specific activity and pattern of enzyme inhibition by antisera raised against IgA1 protease from nine selected strains of H. influenzae. A total of 93% of H. influenzae strains and all H. aegyptius strains had detectable IgA1 protease activity. The majority of strains cleaved a prolyl-seryl or a prolyl-threonyl peptide bond in the alpha 1 hinge region, whereas occasional H. influenzae strains possessed two separate IgA1 proteases with these two specific activities. Of the 155 IgA1 protease-producing strains, all except 12 could be assigned to one of 14 IgA1 protease "inhibition types," each defined by a characteristic pattern of inhibition by the nine antisera. There was no correlation between IgA1 protease type and biotype of the strains. However, among 92 encapsulated H. influenzae strains, a close correlation between capsular serotype and IgA1 protease type was observed. With the exception of serotype f, strains of all capsular serotypes produced an exclusive antigenic type of IgA1 protease. All 38 strains of serotype b produced IgA1 protease of inhibition type 1, which was never demonstrated in non-encapsulated H. influenzae strains. These results facilitate the detection of an antibody response against specific IgA1 proteases and are of practical value for a possible future vaccine against H. influenzae serotype b infections.

  3. Interspecies transfer of the penicillin-binding protein 3-encoding gene ftsI between Haemophilus influenzae and Haemophilus haemolyticus can confer reduced susceptibility to β-lactam antimicrobial agents.

    Science.gov (United States)

    Søndergaard, Annette; Witherden, Elizabeth A; Nørskov-Lauritsen, Niels; Tristram, Stephen G

    2015-07-01

    Mutations in ftsI, encoding penicillin-binding protein 3, can cause decreased β-lactam susceptibility in Haemophilus influenzae. Sequencing of ftsI from clinical strains has indicated interspecies recombination of ftsI between H. influenzae and Haemophilus haemolyticus. This study documented apparently unrestricted homologous recombination of ftsI between H. influenzae and H. haemolyticus in vitro. Transfer of ftsI from resistant isolates conferred similar but not identical increases in the MICs of susceptible strains of H. influenzae and H. haemolyticus.

  4. Haemophilus influenzae type a as a cause of paediatric septic arthritis

    Science.gov (United States)

    Ulanova, Marina

    2016-01-01

    Introduction: Incidence rates of invasive Haemophilus influenzae serotype b disease have decreased significantly since the introduction of the Hib vaccine; however, the rates in indigenous populations remain disproportionately high, specifically in the paediatric population. Additionally, with the decline of type b invasive infections, there has been a rebound in the incidence of invasive infections caused by other strains of H. influenzae, particularly serotype a. Case presentation: We present a paediatric case of septic arthritis caused by H. influenzae type a in a toddler that was fully resolved following antibiotic therapy. This report adds to other reports of septic arthritis in indigenous populations as shown through a review of recently documented H. influenzae type a septic arthritis cases. Conclusion: Socio-economic risk factors for invasive H. influenzae type a disease, such as poverty, poor housing conditions, overcrowding, smoking and substance abuse during pregnancy, as well as the need for H. influenzae type a immunization of vulnerable populations, are discussed.

  5. Genetic diversity of the ftsI gene in β-lactamase-nonproducing ampicillin-resistant and β-lactamase-producing amoxicillin-/clavulanic acid-resistant nasopharyngeal Haemophilus influenzae strains isolated from children in South Korea.

    Science.gov (United States)

    Park, Chulmin; Kim, Kyung-Hyo; Shin, Na-Young; Byun, Ji-Hyun; Kwon, Eun-Young; Lee, Jae-Wook; Kwon, Hyo Jin; Choi, Eu Yoon; Lee, Dong-Gun; Sohn, Woo Yun; Kang, Jin Han

    2013-06-01

    Haemophilus influenzae frequently colonizes the nasopharynx of children and adults, which can lead to a variety of infections. We investigated H. influenzae carriage in the nasopharynx of 360 children, in terms of (1) the prevalence of strains with decreased susceptibility, and (2) the presence of amino acid substitutions in PBP3. One hundred twenty-three strains were isolated (34.2%, 123/360), 122 of which were classified as nontypable H. influenzae (NTHi). Of these, β-lactamase-nonproducing ampicillin-susceptible strains accounted for 26.2%, β-lactamase-producing-ampicillin-resistant strains for 9.0%, β-lactamase-nonproducing ampicillin-resistant (BLNAR) strains for 40.2%, and β-lactamase-producing amoxicillin-/clavulanic acid-resistant (BLPACR) for 24.6%, respectively. Pulsed field gel electrophoresis (PFGE) patterns were so diverse that they were clustered into 41 groups. The amino acid substitutions in the transpeptidase domain (292 amino acids) of ftsI in BLNAR isolates showed that group IIb accounted for 30.6%, IIc for 8.2%, IId for 16.3%, III for 32.7%, and the others for 12.2%. Moreover, groups IIb (56.7%; 17/30) and III (23.3%; 7/30) were prevalent among BLPACR strains. They were subclassified into more diverse sequence subtypes by analysis of the entire PBP3 (610 amino acids). Groups IIb, IIc, IId, and III exhibited 13, four, six, and four sequence subtypes, respectively. Such a genetic diversity is likely indicative of significant potential for decreased antimicrobial susceptibility in nasopharyngeal-colonizing NTHi strains.

  6. A review of the role of Haemophilus influenzae in community-acquired pneumonia

    Directory of Open Access Journals (Sweden)

    Mary PE Slack

    2015-06-01

    Full Text Available In an era when Haemophilus influenzae type b (Hib conjugate vaccine is widely used, the incidence of Hib as a cause of community-acquired pneumonia (CAP has dramatically declined. Non-typeable H. influenzae (NTHi strains and, occasionally, other encapsulated serotypes of H. influenzae are now the cause of the majority of invasive H. influenzae infections, including bacteraemic CAP. NTHi have long been recognised as an important cause of lower respiratory tract infection, including pneumonia, in adults, especially those with underlying diseases. The role of NTHi as a cause of non-bacteraemic CAP in children is less clear. In this review the evidence for the role of NTHi and capsulated strains of H. influenzae will be examined.

  7. Analysis of non-typeable Haemophilus influenzae in invasive disease reveals lack of the capsule locus.

    Science.gov (United States)

    Lâm, T-T; Claus, H; Frosch, M; Vogel, U

    2016-01-01

    Among invasive Haemophilus influenzae, unencapsulated strains have largely surpassed the previously predominant serotype b (Hib) because of Hib vaccination. Isolates without the genomic capsule (cap) locus are designated non-typeable H. influenzae (NTHi). They are different from capsule-deficient variants that show deletion of the capsule transport gene bexA within the cap locus. The frequency of capsule-deficient variants in invasive disease is unknown. We analysed 783 unencapsulated invasive isolates collected over 5 years in Germany and found no single capsule-deficient isolate. Invasive unencapsulated strains in Germany were exclusively NTHi. A negative serotyping result by slide agglutination was therefore highly predictive for NTHi.

  8. Clonal relationship of recent invasive Haemophilus influenzae serotype f isolates from Denmark and the United States

    DEFF Research Database (Denmark)

    Bruun, B; Gahrn-Hansen, B; Westh, H

    2004-01-01

    Surveillance performed after the introduction of general Haemophilus influenzae serotype b (Hib) vaccination in Denmark identified 13 cases of invasive bacteraemic H. influenzae serotype f (Hif) disease in adults over a period of 7 years. Bacteraemic respiratory tract infections accounted for 61...... % of cases, but meningitis, epiglottitis and osteoarthritis were also seen. Recent Danish isolates were compared to recent American isolates, historical Hif strains and non-Hif invasive strains. Results of conventional serotyping were confirmed by PCR detection of the serotype-f-specific cap and bexA gene...

  9. Immunogenicity and Efficacy of Different Haemophilus influenzae type b Vaccines

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    Mojgani, N.

    2014-11-01

    Full Text Available Haemophilus influenzae, a major cause of meningitis in young children leading to death and other neurological sequelae. The disease leaves 15 to 35% of the survivors with permanent disabilities, such as, mental retardation or deafness. Despite the availability of new and more powerful antibiotics children with Hib meningitis still suffer from high mortality or morbidity. The emergence of multiresistant Hib strains causes increasing difficulties in selecting proper antibiotics for the treatment. Since 1970, the capsular polysaccharide polyribosylribitol phosphate (PRP in H. influenzae b has been the target for vaccine development. The first Hib polysaccharide vaccine licensed in 1985, proved immunogenic in human adults, but failed to elicit an immune response in children under 2 years of age who were at greatest risk of developing the invasive Hib infection. These factors led to one of the most exciting advances in pediatrics, the development of Hib conjugate vaccines. Unlike most other vaccines for preventing a particular disease which are generally similar for all types, the specific characteristics of the available Hib conjugate vaccines licensed vary from each other in structure and immunological properties. In this review the immunogenicity and efficacy of Hib vaccines including a PRP vaccine; b Conjugate vaccines; and c Combination vaccines is evaluated.

  10. [Severe Haemophilus influenzae b infection in healthy male adult

    DEFF Research Database (Denmark)

    Vilmar, A.C.; Gjorup, I.; David, Kim Peter

    2008-01-01

    Haemophilus influenzae b (Hib) can be the cause of serious infections, and is mainly observed affecting children and immuno-compromised patients. We report a case of a healthy 49-year old male with a severe Hib infection complicated by septicaemia, meningitis and anuria. The risk of invasive Hib...

  11. Levofloxacin-resistant haemophilus influenzae, Taiwan, 2004-2010.

    Science.gov (United States)

    Kuo, Shu-Chen; Chen, Pei-Chen; Shiau, Yih-Ru; Wang, Hui-Ying; Lai, Jui-Fen; Huang, Wen; Lauderdale, Tsai-Ling Yang

    2014-08-01

    Levofloxacin resistance in Haemophilus influenzae has increased significantly in Taiwan, from 2.0% in 2004 to 24.3% in 2010 (p<0.001). Clinical and molecular investigations of 182 levofloxacin-resistant isolates revealed that the increase was mainly the result of the spread of several clones in the elderly population in different regions.

  12. Susceptibility of Haemophilus aegyptius to trooleandomycin: lack of taxonomic value.

    Science.gov (United States)

    Martel, A Y; Sottnek, F O; Thomas, M L; Albritton, W L

    1986-04-01

    Two hundred and nine strains of Haemophilus influenzae and Haemophilus aegyptius were screened for trooleandomycin susceptibility. Four strains were shown to be sensitive to the drug. Of these four, two were Haemophilus aegyptius (ATCC 11116, NCTC 8134), and the other two were Haemophilus influenzae biotype I (1-605) and IV (80-212. One strain of Haemophilus aegyptius (NCTC 8135) was resistant to trooleandomycin. Restriction enzyme assays and DNA homology were carried out to establish relationships between the strains. It is concluded that trooleandomycin susceptibility has no taxonomic value to differentiate between Haemophilus aegyptius and biotype III Haemophilus influenzae.

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

    Science.gov (United States)

    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.

  14. Comparative Profile of Heme Acquisition Genes in Disease-Causing and Colonizing Nontypeable Haemophilus influenzae and Haemophilus haemolyticus.

    Science.gov (United States)

    Hariadi, Nurul I; Zhang, Lixin; Patel, Mayuri; Sandstedt, Sara A; Davis, Gregg S; Marrs, Carl F; Gilsdorf, Janet R

    2015-07-01

    Nontypeable Haemophilus influenzae (NTHI) are Gram-negative bacteria that colonize the human pharynx and can cause respiratory tract infections, such as acute otitis media (AOM). Since NTHI require iron from their hosts for aerobic growth, the heme acquisition genes may play a significant role in avoiding host nutritional immunity and determining virulence. Therefore, we employed a hybridization-based technique to compare the prevalence of five heme acquisition genes (hxuA, hxuB, hxuC, hemR, and hup) between 514 middle ear strains from children with AOM and 235 throat strains from healthy children. We also investigated their prevalences in 148 Haemophilus haemolyticus strains, a closely related species that colonizes the human pharynx and is considered to be nonpathogenic. Four out of five genes (hxuA, hxuB, hxuC, and hemR) were significantly more prevalent in the middle ear strains (96%, 100%, 100%, and 97%, respectively) than in throat strains (80%, 92%, 93%, and 85%, respectively) of NTHI, suggesting that strains possessing these genes have a virulence advantage over those lacking them. All five genes were dramatically more prevalent in NTHI strains than in H. haemolyticus, with 91% versus 9% hxuA, 98% versus 11% hxuB, 98% versus 11% hxuC, 93% versus 20% hemR, and 97% versus 34% hup, supporting their potential role in virulence and highlighting their possibility to serve as biomarkers to distinguish H. influenzae from H. haemolyticus. In summary, this study demonstrates that heme acquisition genes are more prevalent in disease-causing NTHI strains isolated from the middle ear than in colonizing NTHI strains and H. haemolyticus isolated from the pharynx.

  15. DNA sequence analysis and restriction fragment length polymorphisms of the P1 gene of Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever.

    OpenAIRE

    Reed, R B; Frost, J B; Kort, K; Myers, S.D.; Lesse, A J

    1996-01-01

    Brazilian purpuric fever (BPF) is a fulminant pediatric disease caused by specific strains of Haemophilus influenzae biogroup aegyptius. A conserved epitope on the P1 protein of strains of H. influenzae biogroup aegyptius is seen on most virulent isolates. The P1 protein from a Brazilian case-clone strain of H. influenzae biogroup aegyptius was analyzed by cloning and sequencing the gene. Three major variable regions are present within the P1 gene of the BPF clone in an architecture similar t...

  16. Haemophilus Influenzae Type b (Hib) Vaccine: What You Need to Know

    Science.gov (United States)

    VACCINE INFORMATION STATEMENT Hib Vaccine ( Haemophilus Influenzae Type b) What You Need to Know Many Vaccine Information Statements are available in Spanish and other languages. See www. immunize. ...

  17. Non-Type B Haemophilus Influenzae Meningitis: A Case Report

    Directory of Open Access Journals (Sweden)

    Fatma Deniz Aygun

    2016-02-01

    Full Text Available Haemophilus influenza is one of the most common cause of bacterial meningitis in children. H.influenzae, especially type b (Hib serotype causes invasive infections in children under five years of age. The widespread use of Hib conjugate vaccines has led to a dramatic decline in the incidence of invasive Hib infections. But, the invasive diseases are still reported, particularly nontypeable H. influenzae (noncapsulated remain as an important pathogen. However, there is no evidence that nontypeable H. influenzae infections have increased in frequency. Nontypeable H. Ižnfluenzae serotype is encountered as a cause of acute bacterial meningitis among all ages. In this paper, we present to draw attention to the causative bacterium, in a case of bacterial meningitis caused by nontypeable H. influenzae infection in a child immunized with Hib vaccine.

  18. Insertion sequence IS1016 and absence of Haemophilus capsulation genes in the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Dobson, S R; Kroll, J S; Moxon, E R

    1992-02-01

    Brazilian purpuric fever (BPF) strains of Haemophilus influenzae biogroup aegyptius form a clone of organisms distinct from more innocuous, conjunctivitis-associated isolates. There has been controversy over whether the virulence of BPF strains might derive from the presence of a polysaccharide capsule analogous to that found in conventional invasive H. influenzae, a controversy fuelled by the observation (G. M. Carlone, L. Gorelkin, L. L. Gheesling, A. L. Erwin, S. K. Hoiseth, M. H. O. Mulks, S. P. Connor, R. S. Weyant, J. Myrick, L. Rubin, R. S. Mumford III, E. H. White, R. J. Arko, B. Swaminathan, L. M. Graves, L. W. Mayer, M. K. Robinson, S. P. Caudill, and the Brazilian Purpuric Fever Study Group, J. Clin, Microbiol. 27:609-614, 1989) that a capsulation DNA probe from H. influenzae type b hybridized uniquely to BPF strains. In this work, the basis for this hybridization has been established as the possession by BPF strains, but not by non-BPF strains, of the Haemophilus insertion element IS1016. Although IS1016 is associated with the capsulation locus in some Haemophilus spp., a Southern hybridization study suggests that in BPF strains there are no capsulation genes.

  19. A PCR-high-resolution melt assay for rapid differentiation of nontypeable Haemophilus influenzae and Haemophilus haemolyticus.

    Science.gov (United States)

    Pickering, Janessa; Binks, Michael J; Beissbarth, Jemima; Hare, Kim M; Kirkham, Lea-Ann S; Smith-Vaughan, Heidi

    2014-02-01

    We have developed a PCR-high-resolution melt (PCR-HRM) assay to discriminate nontypeable Haemophilus influenzae (NTHi) colonies from Haemophilus haemolyticus. This method is rapid and robust, with 96% sensitivity and 92% specificity compared to the hpd#3 assay. PCR-HRM is ideal for high-throughput screening for NTHi surveillance and clinical trials.

  20. Meningitis y artritis por Haemophilus influenzae en un adulto

    Directory of Open Access Journals (Sweden)

    Javier Molina

    1988-02-01

    Full Text Available Tradicionalmente el Haemophilus influenzae ha sido considerado un germen causante de infecciones en niños; en adultos se lo ha relacionado con Infecciones respiratorias, pero en los últimos tiempos se han descrito en ellos infecciones severas cuando hay algunos factores predisponentes. Se describe un paciente drogadicto de 30 años con cuadro de meningitis y artritis y prueba de látex y cultivo de LCR positivos para HaemophiIus influenzae, quien recibió tratamiento con ampicilina, 2 gramos Intravenosos cada 4 horas y evolucionó a la mejoría sin secuelas. Se plantea la necesidad de tener en cuenta al Haemophilus influenzae como patógeno del adulto y más en aquellas personas con factores predisponentes.

    Haemophilus influenzae has traditionally been considered as an infectious agent that predominantly affects children; instead, in adults It has been Linked either to respiratory infections or to gevere infections occurring when predisposing factors are present. We describe a 30 year-old drug adict patient that presented with meningitis and arthritis; both latex test and cerebrospinal fluid culture were positive for Haemophilus influenzae. He was treated with ampicilin 2 gm, I. V. every four hours and improved without sequelae. This microorganism must be considered among those affecting adult patients specially when predisposing factors for infection are present.

  1. Distribution and Diversity of hmw1A Among Invasive Nontypeable Haemophilus influenzae Isolates in Iran

    Science.gov (United States)

    Shahini Shams Abadi, Milad; Siadat, Seyed Davar; Vaziri, Farzam; Davari, Mehdi; Fateh, Abolfazl; Pourazar, Shahin; Abdolrahimi, Farid; Ghazanfari, Morteza

    2016-01-01

    Background: The pathogenesis of nontypeable Haemophilus influenzae (NTHi) begins with adhesion to the rhinopharyngeal mucosa. Almost 38–80% of NTHi clinical isolates produce proteins that belong to the High Molecular Weight (HMW) family of adhesins, which are believed to facilitate colonization. Methods: In the present study, the prevalence of hmwA, which encodes the HMW adhesin, was determined for a collection of 32 NTHi isolates. Restriction Fragment Length Polymorphism (RFLP) was performed to advance our understanding of hmwA binding sequence diversity. Results: The results demonstrated that hmwA was detected in 61% of NTHi isolates. According to RFLP, isolates were divided into three groups. Conclusion: Based on these observations, it is hypothesized that some strains of nontypeable Haemophilus influenzae infect some specific areas more than other parts. PMID:27141269

  2. 用于Hib结合疫苗生产的新型候选菌株的评价%Evaluation on a new candidate strain for Haemophilus influenzae type b conjugate vaccine production

    Institute of Scientific and Technical Information of China (English)

    王伟; 马雷钧; 王月红; 朱为; 马相虎

    2011-01-01

    目的 观察b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)760705株在连续传代过程中的稳定性.方法 将Hib 760705株工作种子批菌种连续传代,对第5、第8、第10代Hib培养物进行全面检测,包括培养特性(细菌培养、卫星试验)、染色镜检、生化反应,以检测第5、第8、第10代Hib的生物学特性.同时采用血清凝集试验和聚合酶链反应荚膜分型方法进行b型荚膜多糖稳定性检测.结果 Hib 760705株工作种子批培养物在连续传代过程中具有典型的细菌学特性,能够稳定地产生b型荚膜多糖.结论 Hib 760705株有明确的来源和背景,可以稳定传代,具备作为Hib结合疫苗生产用候选菌株的条件.%Objective To observe the passage stability of Haemophilus influenzae type b(Hib) strain 760705. Methods Hib strain 760705 was cultured for 10 passages from the working seed lot, and the subcultures of the 5th, 8th and 10th passages were detected for biological charactristics comprehensively,including cultural characteristics( bacterial culture and satellite test), staining and microscopic examination,and biochemical reactions. Serological agglutination test and polymerase chain reaction for capsular typing were applied to confirm the generation stability of type b capsular polysaccharide. Results The subcultures of Hib strain 760705 had typical bacteriological characteristics and capability of yielding type b capsular polysaccharide. Conclusions Hib strain 760705 has a clear origin and background and can be subcultured stably, thus suggesting that it can be a candidate strain for Hib conjugate vaccine production.

  3. Repair of ultraviolet-irradiated transforming DNA in A recA mutant of Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Stuy, J.H.; Walter, R.B. (Florida State Univ., Tallahassee (USA). Dept. of Biological Science)

    1983-04-01

    Ultraviolet-irradiated transforming DNA was assayed on a wild-type strain of Haemophilus influenzae strain Rd, on an excision repair-deficient (uvr-2) mutant, on a recombination repair-deficient (recA4) mutant, and on a strain carrying both mutations. The donor DNA had a point mutation genetic marker (strAl) and a long nonhomologous plasmid-derived DNA segment inserted in the HPl prophage. The shape of the inactivation curves suggested that only recombination was responsible for the inverse square root kinetics observed with excision repair-proficient recipients.

  4. Distinct antigenic and genetic properties of the immunoglobulin A1 protease produced by Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever in Brazil.

    OpenAIRE

    Lomholt, H; Kilian, M

    1995-01-01

    All examined Haemophilus influenzae biogroup aegyptius isolates of the clone associated with Brazilian purpuric fever (the BPF clone) produced type 2 immunoglobulin A1 (IgA1) proteases encoded by identical iga genes that were distinct from the iga genes of other Brazilian H. influenzae biogroup aegyptius isolates. A partial nucleotide sequence analysis revealed close similarities to the iga genes of H. influenzae serotype c and one noncapsular H. influenzae biotype III strain isolated from a ...

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

    Science.gov (United States)

    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 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

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

    Science.gov (United States)

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

    2017-02-01

    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 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.

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

    Science.gov (United States)

    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

  8. Quorum signaling and sensing by nontypeable Haemophilus influenzae

    OpenAIRE

    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.

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

    OpenAIRE

    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...

  10. Inducible repair system in Haemophilus influenzae unaccompanied by mutation.

    OpenAIRE

    Notani, N. K.; Setlow, J K

    1980-01-01

    Weigle reactivation of ultraviolet-irradiated HPlc1 phage was observed after ultraviolet or mitomycin C treatment of Haemophilus influenzae cells. The amount of reactivation was considerably increased when the treated cells were incubated in growth medium before infection. The presence of chloramphenicol during this incubation abolished the reactivation. No mutation of this phage accompanied the reactivation. When cells were treated so as to produce a maximal reactivation of phage, neither re...

  11. Inducible repair system in Haemophilus influenzae unaccompanied by mutation. [uv

    Energy Technology Data Exchange (ETDEWEB)

    Notani, N.K.; Setlow, J.K.

    1980-07-01

    Weigle reactivation of ultraviolet-irradiated HPlc1 phage was observed after ultraviolet or mitomycin C treatment of Haemophilus influenzae cells. The amount of reactivation was considerably increased when the treated cells were incubated in growth medium before infection. The presence of chloramphenicol during this incubation abolished the reactivation. No mutation of this phage accompanied the reactivation. When cells were treated so as to produce a maximal reactivation of phage, neither reactivation nor mutation of cells was observed. It is concluded that H. influenzae has an inducible repair system that is not accompanied by mutation.

  12. The capsule biosynthesis locus of Haemophilus influenzae show conspicuous similarity to the corresponding locus in Haemophilus sputorum and may have been recruited from this species by horizontal gene transfer

    DEFF Research Database (Denmark)

    Nielsen, Signe Maria; de Gier, Camilla; Dimopoulou, Chrysoula

    2015-01-01

    in export and processing of the capsular material, show high similarity to the corresponding genes in capsulate lineages of the pathogenic species Haemophilus influenzae; indeed, standard bexA and bexB PCRs for detection of capsulated strains of H. influenzae give positive results with strains of H....... sputorum was only distantly related to H. influenzae. In contrast to H. influenzae, the capsule locus in H. sputorum is not associated with transposases or other transposable elements. Our data suggest that the capsule locus of capsulate lineages of H. influenzae may relatively recently have been recruited...

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

    Science.gov (United States)

    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; Apicella, Michael A

    2016-01-04

    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.

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

    Science.gov (United States)

    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

  15. Glycerophosphorylcholine regulates Haemophilus influenzae glpQ gene expression.

    Science.gov (United States)

    Alrousan, Enas; Fan, Xin

    2015-05-01

    An important virulence strategy adopted by Haemophilus influenzae to establish a niche on the mucosal surface of the host is the phosphorylcholine (ChoP) decoration of its lipopolysaccharides, which promotes adherence to the host cells. Haemophilus influenzae is able to use glycerophosphorylcholine (GPC) from host for ChoP synthesis. Utilization of GPC requires glpQ, which encodes a glycerophosphodiester phosphodiesterase enzyme. In this study, we investigate the transcriptional regulation of glpQ gene using real-time PCR and transcriptional fusion of H. influenzae glpQ promoter to the Escherichia coli lacZ reporter gene. The glpQ promoter activities were examined under environmental conditions including changes in temperature, oxygen, high salt and minimal growth medium. Our data showed that under room temperature and anaerobic conditions, the glpQ gene expression levels were significantly higher than under other growth conditions. In addition, the glpQ gene expression levels were upregulated in the presence of GPC. These results suggest that H. influenzae may upregulate glpQ expression in response to different environments it encounters during infection, from the airway surfaces (room temperature) to deep tissues (anaerobic). Upregulation of glpQ by GPC may allow efficient use of abundant GPC from mammalian cells by H. influenzae as a source of nutrient and for ChoP decoration of lipopolysaccharide that facilitates bacterial adhesion to host cells and growth during infection.

  16. Inflammatory response of Haemophilus influenzae biotype aegyptius causing Brazilian Purpuric Fever

    Directory of Open Access Journals (Sweden)

    Gisele Cristiane Gentile Cury

    2014-12-01

    Full Text Available The Brazilian Purpuric Fever (BPF is a systemic disease with many clinical features of meningococcal sepsis and is usually preceded by purulent conjunctivitis. The illness is caused by Haemophilus influenza biogroup aegyptius, which was associated exclusively with conjunctivitis. In this work construction of the las gene, hypothetically responsible for this virulence, were fusioned with ermAM cassette in Neisseria meningitidis virulent strains and had its DNA transfer to non BPF H. influenzae strains. The effect of the las transfer was capable to increase the cytokines TNFα and IL10 expression in Hec-1B cells line infected with these transformed mutants (in eight log scale of folding change RNA expression. This is the first molecular study involving the las transfer to search an elucidation of the pathogenic factors by horizontal intergeneric transfer from meningococci to H. influenzae.

  17. Inflammatory response of Haemophilus influenzae biotype aegyptius causing Brazilian Purpuric Fever.

    Science.gov (United States)

    Cury, Gisele Cristiane Gentile; Pereira, Rafaella Fabiana Carneiro; de Hollanda, Luciana Maria; Lancellotti, Marcelo

    2014-01-01

    The Brazilian Purpuric Fever (BPF) is a systemic disease with many clinical features of meningococcal sepsis and is usually preceded by purulent conjunctivitis. The illness is caused by Haemophilus influenza biogroup aegyptius, which was associated exclusively with conjunctivitis. In this work construction of the las gene, hypothetically responsible for this virulence, were fusioned with ermAM cassette in Neisseria meningitidis virulent strains and had its DNA transfer to non BPF H. influenzae strains. The effect of the las transfer was capable to increase the cytokines TNFα and IL10 expression in Hec-1B cells line infected with these transformed mutants (in eight log scale of folding change RNA expression). This is the first molecular study involving the las transfer to search an elucidation of the pathogenic factors by horizontal intergeneric transfer from meningococci to H. influenzae.

  18. Inflammatory response of Haemophilus influenzae biotype aegyptius causing Brazilian Purpuric Fever

    Science.gov (United States)

    Cury, Gisele Cristiane Gentile; Pereira, Rafaella Fabiana Carneiro; de Hollanda, Luciana Maria; Lancellotti, Marcelo

    2014-01-01

    The Brazilian Purpuric Fever (BPF) is a systemic disease with many clinical features of meningococcal sepsis and is usually preceded by purulent conjunctivitis. The illness is caused by Haemophilus influenza biogroup aegyptius, which was associated exclusively with conjunctivitis. In this work construction of the las gene, hypothetically responsible for this virulence, were fusioned with ermAM cassette in Neisseria meningitidis virulent strains and had its DNA transfer to non BPF H. influenzae strains. The effect of the las transfer was capable to increase the cytokines TNFα and IL10 expression in Hec-1B cells line infected with these transformed mutants (in eight log scale of folding change RNA expression). This is the first molecular study involving the las transfer to search an elucidation of the pathogenic factors by horizontal intergeneric transfer from meningococci to H. influenzae. PMID:25763053

  19. Haemophilus influenzae Pyomyositis in a Patient with Diabetic Ketoacidosis: A Unique Case and Review of Literature

    Directory of Open Access Journals (Sweden)

    Kamolyut Lapumnuaypol

    2017-01-01

    Full Text Available Haemophilus influenzae is a Gram-negative bacillus commonly known to cause upper respiratory tract infections. Skin and soft tissue infections are very uncommon. Of these, the majority were associated with necrotizing fasciitis requiring emergent debridement. We report a case of pyomyositis caused by Haemophilus influenzae in an adult with diabetes.

  20. [Haemophilus influenzae purulent meningitis in adults: looking for a predisposing factor].

    Science.gov (United States)

    Boukadida, Jalel; Hannachi, Neila

    2002-05-01

    We bring back an adult case of purulent meningitis to Haemophilus influenzae. We insist on the particular aspects of the host of this meningitis type at the adult. These aspects must be searched every time that Haemophilus influenzae is isolated in cerebrospinal fluid in adult's meningitis.

  1. Haemophilus influenzae Pyomyositis in a Patient with Diabetic Ketoacidosis: A Unique Case and Review of Literature

    Science.gov (United States)

    George, Gemlyn; Climaco, Antoinette

    2017-01-01

    Haemophilus influenzae is a Gram-negative bacillus commonly known to cause upper respiratory tract infections. Skin and soft tissue infections are very uncommon. Of these, the majority were associated with necrotizing fasciitis requiring emergent debridement. We report a case of pyomyositis caused by Haemophilus influenzae in an adult with diabetes. PMID:28352482

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

    Science.gov (United States)

    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.

  3. Activities of ceftobiprole, a novel broad-spectrum cephalosporin, against Haemophilus influenzae and Moraxella catarrhalis.

    Science.gov (United States)

    Bogdanovich, Tatiana; Clark, Catherine; Ednie, Lois; Lin, Gengrong; Smith, Kathy; Shapiro, Stuart; Appelbaum, Peter C

    2006-06-01

    Ceftobiprole, a broad-spectrum pyrrolidinone-3-ylidenemethyl cephem currently in phase III clinical trials, had MICs between 0.008 microg/ml and 8.0 microg/ml for 321 clinical isolates of Haemophilus influenzae and between Ceftobiprole MIC(50) and MIC(90) values for H. influenzae were 0.06 microg/ml and 0.25 microg/ml for beta-lactamase-positive strains (n = 262), 0.03 microg/ml and 0.25 microg/ml for beta-lactamase-negative strains (n = 40), and 0.5 microg/ml and 2.0 microg/ml for beta-lactamase-negative ampicillin-resistant strains (n = 19), respectively. Ceftobiprole MIC(50) and MIC(90) values for beta-lactamase-positive M. catarrhalis strains (n = 40) were 0.12 microg/ml and 0.5 microg/ml, respectively, whereas the ceftobiprole MIC range for beta-lactamase-negative M. catarrhalis strains (n = 9) was ceftobiprole, whereas amoxicillin-clavulanate MICs usually were higher than those of ceftobiprole. Azithromycin and telithromycin had unimodal MIC distributions against H. influenzae, with MIC(90) values of azithromycin and telithromycin of 2 microg/ml and 4 microg/ml, respectively. Except for selected quinolone-nonsusceptible H. influenzae strains, moxifloxacin proved highly active, with MIC(90) values of 0.12 microg/ml. Time-kill analyses showed that ceftobiprole, ceftriaxone, cefpodoxime, amoxicillin-clavulanate, azithromycin, telithromycin, and moxifloxacin were bactericidal at 2x MIC by 24 h against all 10 H. influenzae strains surveyed. Only modest increases in MICs were found for H. influenzae or M. catarrhalis clones after 50 serial passages in the presence of subinhibitory concentrations of ceftobiprole, and single-passage selection showed that the selection frequency of H. influenzae or M. catarrhalis clones with elevated ceftobiprole MICs is quite low.

  4. Antibiotic resistance of streptococcus pneumoniae and haemophilus influenzae isolated from respiratory tract specimens

    Directory of Open Access Journals (Sweden)

    Hikmet Eda Aliskan

    2016-06-01

    Full Text Available Purpose: Streptococcus pneumoniae and Haemophilus influenzae are two of the major pathogens in respiratory infections, treatment is usually started empirically. The aim of this study was to detect in vitro resistance rates of S. pneumoniae and H. influenzae strains isolated from different lower respiratory clinical samples to the antibotics which are used for therapy of infections due to these pathogens. Material and Methods: Seventy seven S.pneumoniae and 117 H.influenzae strains, isolated from patients were included in the study. S.pneumoniae isolates which gave an inhibition zone diameter of >20 mm for oxacillin were considered susceptible for penicilin. For the isolates which had an oxacillin zone diameter of 2 mg/l and 31.1 % were intermediately resistant to parenteral penicillin. Resistance rates to antibiotics were as follows: erythromycin 40 %, trimethoprim/sulphametoxazole (TMP/SMX 54.5 % and ofloxacin 6.4%. beta-lactamases were detected in 15.6% of the H.influenzae isolates by nitrocefin positivity. Conclusion: H.influenzae strains (8.6% were identified as beta-lactamase negative ampicillin resistant (BLNAR strains. Resistance rates for other antibiotics were as follows: ampicillin 28.6%, cefaclor 36.5% , cefuroxime 30.1%, clarithromycin 9.6%, cloramphenicol 7% and TMP-SMX 43.9%. [Cukurova Med J 2016; 41(2.000: 201-207

  5. Haemophilus influenzae stores and distributes hemin by using protein E.

    Science.gov (United States)

    Al Jubair, Tamim; Singh, Birendra; Fleury, Christophe; Blom, Anna M; Mörgelin, Matthias; Thunnissen, Marjolein M; Riesbeck, Kristian

    2014-07-01

    The human pathogen Haemophilus influenzae causes mainly respiratory tract infections such as acute otitis media in children and exacerbations in patients with chronic obstructive pulmonary disease. We recently revealed the crystal structure of H. influenzeae protein E (PE), a multifunctional adhesin that is involved in direct interactions with lung epithelial cells and host proteins. Based upon the PE structure we here suggest a hypothetical binding pocket that is compatible in size with a hemin molecule. An H. influenzae mutant devoid of PE bound significantly less hemin in comparison to the PE-expressing wild type counterpart. In addition, E. coli expressing PE at the surface resulted in a hemin-binding phenotype. An interaction between hemin and recombinant soluble PE was also demonstrated by native-PAGE and UV-visible spectrophotometry. Surface plasmon resonance revealed an affinity (Kd) of 1.6 × 10(-6)M for the hemin-PE interaction. Importantly, hemin that was bound to PE at the H. influenzae surface, was donated to co-cultured luciferase-expressing H. influenzae that were starved of hemin. When hemin is bound to PE it thus may serve as a storage pool for H. influenzae. To our knowledge this is the first report showing that H. influenzae can share hemin via a surface-located outer membrane protein.

  6. Airway dysbiosis: Haemophilus influenzae and Tropheryma in poorly controlled asthma.

    Science.gov (United States)

    Simpson, Jodie L; Daly, Joshua; Baines, Katherine J; Yang, Ian A; Upham, John W; Reynolds, Paul N; Hodge, Sandra; James, Alan L; Hugenholtz, Philip; Willner, Dana; Gibson, Peter G

    2016-03-01

    Asthma is a chronic inflammatory disorder of the airways where bacteria may act as protagonists of chronic inflammation. Little is known about the relation of airway inflammation to the presence of specific bacterial taxa. We sought to describe the sputum microbiome in adults with poorly controlled asthma.DNA was extracted from induced sputum and microbial communities were profiled using 16S rRNA pyrosequencing. Bacterial species were characterised, and the relationship between microbial populations, asthma inflammatory subtypes and other covariates was explored. Real-time PCR was used to identify Tropheryma whipplei and Haemophilus influenzae in sputum.Adults with neutrophilic asthma had reduced bacterial diversity and species richness. Tropheryma was identified and confirmed with real-time PCR in 12 (40%) participants. Haemophilus occurred most often in a group of younger atopic males with an increased proportion of neutrophils. PCR confirmed the presence of H. influenzae in 35 (76%) participants with poorly controlled asthma.There are phenotype-specific alterations to the airway microbiome in asthma. Reduced bacterial diversity combined with a high prevalence of H. influenzae was observed in neutrophilic asthma, whereas eosinophilic asthma had abundant T. whipplei.

  7. Genetics and complementation of Haemophilus influenzae mutants deficient in adenosine 5'-triphosphate-dependent nuclease

    Energy Technology Data Exchange (ETDEWEB)

    Kooistra, J.; Small, G.D.; Setlow, J.K.; Shapanka, R.

    1976-04-01

    Eight different mutations in Haemophilus influenzae leading to deficiency in adenosine 5'-triphosphate (ATP)-dependent nuclease have been investigated in strains in which the mutations of the originally mutagenized strains have been transferred into the wild type. Sensitivity to mitomycin C and deoxycholate and complementation between extracts and deoxyribonucleic acid (DNA)-dependent ATPase activity have been measured. Genetic crosses have provided information on the relative position of the mutations on the genome. There are three complementation groups, corresponding to three genetic groups. The strains most sensitive to mitomycin and deoxycholate, derived from mutants originally selected on the basis of sensitivity to mitomycin C or methyl methanesulfonate, are in one group. Apparently all these sensitive strains lack DNA-dependent ATPase activity, as does a strain intermediate in sensitivity to deoxycholate, which is the sole representative of another group. There are four strains that are relatively resistant to deoxycholate and mitomycin C, and all of these contain the ATPase activity.

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

    Science.gov (United States)

    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.

  9. Similarity in properties and mapping of three rec mutants of Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Kooistra, J.; Setlow, J.K.

    1976-07-01

    Three Rec/sup -/ mutants of Haemophilus influenzae have been studied with respect to their transformability, ultraviolet and mitomycin C sensitivities, spontaneous and ultraviolet-induced deoxyribonucleic acid breakdown, inducibility of lysogens, and the linkage of the three mutations to a streptomycin resistance marker. The data indicate that the three mutations cause the same phenotypic changes, and that they are all on the same gene. Transformability of the mutants is different when two different media are used for competence development, although transformability with the two competence methods is not different in a Rec/sup -/ strain that is mutant at another gene.

  10. Genetic control of prophage induction in Haemophilus influenzae after exposure to psoralen plus near-uv light

    Energy Technology Data Exchange (ETDEWEB)

    George, M.; Notani, N.K.

    1980-09-01

    Prophage S2 could be induced by psoralen plus near-uv light (PNUV) from a wild-type strain of Haemophilus influenzae, from uv light-sensitive strains uvr-1 and uvr-2, and PNUV-sensitive strains PSO1 and PSO7, but not from a recombination-deficient strain, rec-1. The levels of prophage induction were comparable in the wild type and an ATP-dependent DNase-deficient strain, KW31, even though the PNUV-induced degradation in the latter strain was considerably lower. Prophage induction could be observed even with chloramphenicol present before, during, and 30 min after PNUV treatment.

  11. [Peritonitis in the course of peritoneal dialisis caused by Haemophilus influenzae with BLNAR phenotype].

    Science.gov (United States)

    Miklaszewska, Monika; Klepacka, Joanna; Drozdz, Dorota; Zachwieja, Katarzyna; Pietrzyk, Jacek A; Kadłubowski, Marcin; Hryniewicz, Waleria

    2009-04-01

    Most common bacterial species causing peritonitis in the course of peritoneal dialysis (PDP) are coagulase-negative staphylococci, Staphylococcus aureus and streptococci. Haemophilus influenzae is rarely associated with PDP. Hereby we present the first known case of APD-associated peritonitis caused by non-type able H. influenzae (NTHi) presenting the beta-lactamase negative, ampicillin-resistant (BLNAR) phenotype. An 18 year old boy who had been treated with the APD for 12 months due to SLE was admitted in good general condition with diagnosis of PDP. Standard diagnostic and therapeutical procedures were initiated. Dialysis fluid was turbid with cytosis of 435 WBC/ml. From dialysis fluid pure culture of Gram-negative coccobacillus was isolated. The isolate was identified as a BLNAR phenotype. The same bacterium was isolated from nasal swab. Blood cultures were negative. After evaluation of antimicrobial susceptibility the treatment was changed for the oral ciprofloxacin. The treatment was successful. Control tests 2 days later revealed cytosis of 15 WBC/mm3 and control cultures of peritoneal fluid were negative. After two weeks of treatment the patient was discharged in a good condition. Haemophilus influenzae is a bacterium frequently colonizing the nasopharyngeal cavity. A PCR-based method allowed to classify isolates as NTHi. Infection was probably of the respiratory origin as the isolates (from peritoneal fluid and nasal swab) were undistinguishable. There are only few reports describing this species as an ethiologic agent of peritonitis. This case prove that Haemophilus species should be taken into account as a possible aethiologic agent of PDP, especially in patients on immunosupression with carrier state of H. influenzae in the upper respiratory tract. This kind of microorganism requires specific conditions during its growing in vitro. Identification of its sensitivity to antibiotics is essential in order to detect strains of BLNAR phenotype, as it is a

  12. Haemophilus haemolyticus interaction with host cells is different to nontypeable Haemophilus influenzae and prevents NTHi association with epithelial cells

    Directory of Open Access Journals (Sweden)

    Janessa Lea Pickering

    2016-05-01

    Full Text Available 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-strain variability but overall, H. haemolyticus had reduced capacity to attach to and invade nasopharyngeal and bronchoalveolar epithelial cell lines (D562 and A549 within 3h when compared with NTHi. H. haemolyticus was cytotoxic to both cell lines at 24h, 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

  13. 128株流感嗜血菌对抗菌药物耐药性分析%Drug resistance of 128 strains of haemophilus influenzae to antibiotics

    Institute of Scientific and Technical Information of China (English)

    张有忠; 都青; 李娜

    2011-01-01

    目的 对襄樊市中医院2008-2009年临床微生物室分离出的流感嗜血菌耐药性及耐药趋势进行回顾性分析,为指导临床合理用药提供科学依据;同时优化检测方法,提高检出率.方法 对128株流感嗜血菌进行β-内酰胺酶测定,采用K-B法进行体外药敏试验.结果 128例流感嗜血菌中,产β-内酰胺酶率为28.69%,对氨苄西林、氨苄西林/舒巴坦、头孢噻肟、磺胺甲噁唑/甲氧苄啶、头孢呋辛、环丙沙星、阿奇霉素、左氧氟沙星、氯霉素、亚胺培南的耐药率分别为47.66%、15.63%、28.91%、56.25%、27.34%、19.53%、19.53%、29.69%、46.09%、0.结论 流感嗜血菌对亚胺培南、氨苄西林/舒巴坦、环丙沙星、阿奇霉素的敏感性较高,临床医师可选择这些药物进行治疗.%OBJECTIVE To retrospectively analyze the drug resistance trend and drug resistance of Haemophiius influenzae isolated from clinical microorganism room in the Xiangfan Traditional Chinese Medicine H ospital in the whole year of 2009, to provide scientific data for the clinical on rational drug use and optimize the detection method and improve the detection rate. METHODS The determination of β-lactamase was performed on 128 strains of HI and drug sensitivity was tested in vitro by using the method of Kirty-Bauer. RESULTS In 128 strains of H. influenzae, the β-lactamase producing rate was 28.69%, the drug resistant rates to ampicillin, ampicillin sulbactam,cefotaxime, cotrimoxazole, cefuroxime, ciprofloxacin, azithromycin, levofloxacin, chloramphenicol and imipenem were 47. 66%, 15. 63%, 28. 91%, 56. 25%, 27. 34%, 19. 53%, 19. 53%, 29.69%, 46. 09% and 0,respectively. CONCLUSION H. influenzae is sensitive to imipenem, ampicillin/sulbactam, ciprofloxacin and azithromycin, the clinicians can choose these drugs for the treatment.

  14. Epidemiology of Haemophilus influenzae bacteremia: A multi-national population-based assessment

    DEFF Research Database (Denmark)

    Laupland, Kevin B; Schønheyder, Henrik C; Østergaard, Christian

    2011-01-01

    independently associated with death at 30-days in logistic regression analysis included male gender, hospital-onset disease, older age, and lower respiratory tract, central nervous system, or unknown focus of infection. CONCLUSIONS: Haemophilus influenzae is an important cause of morbidity and mortality......OBJECTIVES: Haemophilus influenzae is an important cause of invasive infection but contemporary data in non-selected populations is limited. METHODS: Population-based surveillance for Haemophilus influenzae bacteremia was conducted in seven regions in Australia, Canada, and Denmark during 2000...

  15. PnuC and the utilization of the nicotinamide riboside analog 3-aminopyridine in Haemophilus influenzae.

    Science.gov (United States)

    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.

  16. The dppBCDF gene cluster of Haemophilus influenzae: Role in heme utilization

    Directory of Open Access Journals (Sweden)

    Morton Daniel J

    2009-08-01

    Full Text Available Abstract Background Haemophilus influenzae requires a porphyrin source for aerobic growth and possesses multiple mechanisms to obtain this essential nutrient. This porphyrin requirement may be satisfied by either heme alone, or protoporphyrin IX in the presence of an iron source. One protein involved in heme acquisition by H. influenzae is the periplasmic heme binding protein HbpA. HbpA exhibits significant homology to the dipeptide and heme binding protein DppA of Escherichia coli. DppA is a component of the DppABCDF peptide-heme permease of E. coli. H. influenzae homologs of dppBCDF are located in the genome at a point distant from hbpA. The object of this study was to investigate the potential role of the H. influenzae dppBCDF locus in heme utilization. Findings An insertional mutation in dppC was constructed and the impact of the mutation on the utilization of both free heme and various proteinaceous heme sources as well as utilization of protoporphyrin IX was determined in growth curve studies. The dppC insertion mutant strain was significantly impacted in utilization of all tested heme sources and protoporphyin IX. Complementation of the dppC mutation with an intact dppCBDF gene cluster in trans corrected the growth defects seen in the dppC mutant strain. Conclusion The dppCBDF gene cluster constitutes part of the periplasmic heme-acquisition systems of H. influenzae.

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

    Science.gov (United States)

    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.

  18. Molecular Serotype-Specific Identification of Non-type b Haemophilus influenzae by Loop-Mediated Isothermal Amplification

    Directory of Open Access Journals (Sweden)

    Chika Takano

    2017-10-01

    Full Text Available Over the past four decades, the incidence of meningitis caused by Haemophilus influenzae in children has decreased due to widespread vaccination against H. influenzae type b (Hib. The incidence of invasive diseases due to H. influenzae types not included in the vaccines, however, has increased. At present, there are a limited number of diagnostics available to detect non-type b H. influenzae. To address this issue, we developed a rapid, simple, and cost-effective method for detecting serotypes of H. influenzae. We designed LAMP primer sets based on published sequences for H. influenzae capsular types a, c, d, e, and f. The assay was evaluated to determine test reactivity, specificity, and sensitivity. To support its use in patients with suspected meningitis, we evaluated the detection limit of the non-Hib serotype specific LAMP assay using bacterial genomic DNA-spiked cerebrospinal fluid (CSF specimens. The reactivity and specificity of the LAMP assays were confirmed using six serotypes and non-typeable H. influenzae strains, plus eight strains of other Haemophilus species and non-Haemophilus genera. The detection limits of the LAMP assay for capsular types a, c, d, e, and f were 102, 102, 102, 103, and 10 copies per reaction, while those of the PCR assay were 104, 104, 103, 103, and 104 genome copies per reaction, respectively. Using DNA-spiked CSF specimens, the detection limit of the LAMP assay was equivalent to that using purified DNA as the template. However, the detection limit of the PCR was reduced from 103 to 104 genome copies per reaction for serotype d and from 103 to 105 genome copies per reaction for serotype e. To the best of our knowledge, this is the first report of a serotype-specific identification assay for H. influenzae using the LAMP method. Our results suggest the potential of LAMP methods for patients with suspected meningitis in resource-limited laboratories or public health surveillance systems.

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

    Science.gov (United States)

    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.

  20. Resistance to serum bactericidal activity distinguishes Brazilian purpuric fever (BPF) case strains of Haemophilus influenzae biogroup aegyptius (H. aegyptius) from non-BPF strains. Brazilian Purpuric Fever Study Group.

    OpenAIRE

    Porto, M H; Noel, G J; Edelson, P J

    1989-01-01

    We studied the ability of normal human serum to lyse H. influenzae biogroup aegyptius (H. aegyptius) isolates recovered from patients with Brazilian purpuric fever (BPF clone) or non-BPF clone strains. BPF clone isolates, although similar to non-BPF clone isolates with regard to the ability to fix C3 to their surfaces, could be distinguished from non-BPF clone strains by their resistance to lysis in vitro following incubation with normal adult human serum.

  1. Resistance to serum bactericidal activity distinguishes Brazilian purpuric fever (BPF) case strains of Haemophilus influenzae biogroup aegyptius (H. aegyptius) from non-BPF strains. Brazilian Purpuric Fever Study Group.

    Science.gov (United States)

    Porto, M H; Noel, G J; Edelson, P J

    1989-04-01

    We studied the ability of normal human serum to lyse H. influenzae biogroup aegyptius (H. aegyptius) isolates recovered from patients with Brazilian purpuric fever (BPF clone) or non-BPF clone strains. BPF clone isolates, although similar to non-BPF clone isolates with regard to the ability to fix C3 to their surfaces, could be distinguished from non-BPF clone strains by their resistance to lysis in vitro following incubation with normal adult human serum.

  2. Nationwide survey of the development of drug resistance in the pediatric field in 2007 and 2010: drug sensitivity of Haemophilus influenzae in Japan (second report)

    OpenAIRE

    Hoshino, Tadashi; Sato, Yoshitake; Toyonaga, Yoshikiyo; Hanaki, Hideaki; Sunakawa, Keisuke; ,

    2013-01-01

    The Drug-Resistant Pathogen Surveillance Group in Pediatric Infectious Disease conducted national surveillance for Haemophilus influenzae in 2007 (phase 3) and 2010 (phase 4), following the previous surveillance conducted from 2000 to 2001 (phase 1) and in 2004 (phase 2). We examined the antimicrobial susceptibility for H. influenzae derived from clinical specimens of pediatric patients collected nationwide from 27 institutions during phases 3 (386 strains) and 4 (484 strains). The frequency ...

  3. A basis for vaccine development: Comparative characterization of Haemophilus influenzae outer membrane vesicles.

    Science.gov (United States)

    Roier, Sandro; Blume, Thomas; Klug, Lisa; Wagner, Gabriel E; Elhenawy, Wael; Zangger, Klaus; Prassl, Ruth; Reidl, Joachim; Daum, Günther; Feldman, Mario F; Schild, Stefan

    2015-05-01

    Outer membrane vesicles (OMVs) are spherical and bilayered particles that are naturally released from the outer membrane (OM) of Gram-negative bacteria. They have been proposed to possess several biological roles in pathogenesis and interbacterial interactions. Additionally, OMVs have been suggested as potential vaccine candidates against infections caused by pathogenic bacteria like Haemophilus influenzae, a human pathogen of the respiratory tract. Unfortunately, there is still a lack of fundamental knowledge regarding OMV biogenesis, protein sorting into OMVs, OMV size and quantity, as well as OMV composition in H. influenzae. Thus, this study comprehensively characterized and compared OMVs and OMs derived from heterologous encapsulated as well as nonencapsulated H. influenzae strains. Semiquantitative immunoblot analysis revealed that certain OM proteins are enriched or excluded in OMVs suggesting the presence of regulated protein sorting mechanisms into OMVs as well as interconnected OMV biogenesis mechanisms in H. influenzae. Nanoparticle tracking analysis, transmission electron microscopy, as well as protein and lipooligosaccharide quantifications demonstrated that heterologous H. influenzae strains differ in their OMV size and quantity. Lipidomic analyses identified palmitic acid as the most abundant fatty acid, while phosphatidylethanolamine was found to be the most dominant phospholipid present in OMVs and the OM of all strains tested. Proteomic analysis confirmed that H. influenzae OMVs contain vaccine candidate proteins as well as important virulence factors. These findings contribute to the understanding of OMV biogenesis as well as biological roles of OMVs and, in addition, may be important for the future development of OMV based vaccines against H. influenzae infections. Copyright © 2015. Published by Elsevier GmbH.

  4. Comparison of laboratory-based and phylogenetic methods to distinguish between Haemophilus influenzae and H. haemolyticus

    Science.gov (United States)

    Sandstedt, Sara A.; Zhang, Lixin; Patel, Mayurika; McCrea, Kirk W.; Qin, Zhaohui; Marrs, Carl F.; Gilsdorf, Janet R.

    2008-01-01

    Summary New methods to distinguish between nontypeable Haemophilus influenzae and nonhemolytic Haemophilus haemolyticus were compared. The results of iga variable region hybridization to dotblots and library-on-a-slide microarrays were more similar to a “gold standard” multigene phylogenetic tree than iga conserved region hybridization or P6 7F3 epitope immunoblots. PMID:18652852

  5. Implications of Haemophilus influenzae biogroup aegyptius hemagglutinins in the pathogenesis of Brazilian purpuric fever.

    Science.gov (United States)

    Barbosa, Sônia F C; Hoshino-Shimizu, Sumie; Alkmin, Maria das Graças A; Goto, Hiro

    2003-07-01

    Brazilian purpuric fever (BPF) is an acute disease caused by Haemophilus influenzae biogroup aegyptius; it is characterized by fever, purpura, and hypotensive shock and is usually fatal. The factors responsible for bacterial virulence and pathogenesis are poorly known. Hemagglutinins have been frequently associated with bacterial virulence, and, in the present study, hemagglutinating activity was detected in extracellular products from H. influenzae biogroup aegyptius strains isolated from patients with BPF. A 60-kilodalton (kDa) molecule absorbable by human O-type erythrocytes was identified by an immunoblot assay; a corresponding fraction was chromatographically purified, and its pathogenic effect was evaluated. Rabbits injected intravenously with either the whole bacterial extracellular product or the 60-kDa fraction showed reactions similar to those seen in patients with BPF: purpura, congestion, and fibrin thrombi in the inner organs. We suggest that this hemagglutinating factor is one of the major pathogenic components of BPF.

  6. Haemophilus influenzae OxyR: characterization of its regulation, regulon and role in fitness.

    Directory of Open Access Journals (Sweden)

    Paul W Whitby

    Full Text Available 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.

  7. Haemophilus influenzae OxyR: Characterization of Its Regulation, Regulon and Role in Fitness

    Science.gov (United States)

    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

  8. Onderzoek naar de gevoeligheid van streptococcus pneumoniae, haemophilus influenzae en Moraxella catarrhalis voor antibiotica

    NARCIS (Netherlands)

    de Neeling AJ; Overbeek BP; Timmerman CP; de Jong J; Dessens-Kroon M; van Klingeren B

    1992-01-01

    The susceptibility to antibiotics of three respiratory pathogens, Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis, was determined. The isolates were obtainied in three regional laboratories in the Netherlands and tested using the microdilution method. After incubation th

  9. Nucleotide sequence analysis of hypervariable junctions of Haemophilus influenzae pilus gene clusters.

    Science.gov (United States)

    Read, T D; Satola, S W; Farley, M M

    2000-12-01

    Haemophilus influenzae pili are surface structures that promote attachment to human epithelial cells. The five genes that encode pili, hifABCDE, are found inserted in genomes either between pmbA and hpt (hif-1) or between purE and pepN (hif-2). We determined the sequence between the ends of the pilus clusters and bordering genes in a number of H. influenzae strains. The junctions of the hif-1 cluster (limited to biogroup aegyptius isolates) are structurally simple. In contrast, hif-2 junctions are highly diverse, complex assemblies of conserved intergenic sequences (including genes hicA and hicB) with evidence of frequent recombination. Variation at hif-2 junctions seems to be tied to multiple copies of a 23-bp Haemophilus intergenic dyad sequence. The hif-1 cluster appears to have originated in biogroup aegyptius strains from invasion of the hpt-pmbA region by a DNA template containing the hif-2 genes with termini in the hairpin loop of flanking intergenic dyad sequences. The pilus gene clusters are an interesting model of a mobile "pathogenicity island" not associated with a phage, transposon, or insertion element.

  10. 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.

    Science.gov (United States)

    de Gier, Camilla; Kirkham, Lea-Ann S; Nørskov-Lauritsen, Niels

    2015-12-01

    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.

  11. Expression of IgA Proteases by Haemophilus influenzae in the Respiratory Tract of Adults With Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Murphy, Timothy F; Kirkham, Charmaine; Jones, Megan M; Sethi, Sanjay; Kong, Yong; Pettigrew, Melinda M

    2015-12-01

    Immunoglobulin (Ig)A proteases of Haemophilus influenzae are highly specific endopeptidases that cleave the hinge region of human IgA1 and also mediate invasion and trafficking in human respiratory epithelial cells, facilitating persistence of H. influenzae. Little is known about the expression of IgA proteases in clinical settings of H. influenzae infection. We identified and characterized IgA protease genes in H. influenzae and studied their expression and proteolytic specificity, in vitro and in vivo in 169 independent strains of H. influenzae collected longitudinally over 10 years from adults with chronic obstructive pulmonary disease. The H. influenzae pangenome has 2 alleles of IgA protease genes; all strains have igaA, and 40% of strains have igaB. Each allele has 2 variants with differing proteolytic specificities for human IgA1. A total of 88% of 169 strains express IgA protease activity. Expression of the 4 forms of IgA protease varies among strains. Based on the presence of IgA1 fragments in sputum samples, each of the different forms of IgA protease is selectively expressed in the human airways during infection. Four variants of IgA proteases are variably expressed by H. influenzae during infection of the human airways. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

    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.

  13. Phosphorylcholine allows for evasion of bactericidal antibody by Haemophilus influenzae.

    Directory of Open Access Journals (Sweden)

    Sarah E Clark

    Full Text Available 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.

  14. Investigations into genome diversity of Haemophilus influenzae using whole genome sequencing of clinical isolates and laboratory transformants

    Directory of Open Access Journals (Sweden)

    Power Peter M

    2012-11-01

    Full Text Available Abstract Background Haemophilus influenzae is an important human commensal pathogen associated with significant levels of disease. High-throughput DNA sequencing was used to investigate differences in genome content within this species. Results Genomic DNA sequence was obtained from 85 strains of H. influenzae and from other related species, selected based on geographical site of isolation, disease association and documented genotypic and phenotypic differences. When compared by Mauve alignment these indicated groupings of H. influenzae that were consistent with previously published analyses; capsule expressing strains fell into two distinct groups and those of serotype b (Hib were found in two closely positioned lineages. For 18 Hib strains representing both lineages we found many discrete regions (up to 40% of the total genome displaying sequence variation when compared to a common reference strain. Evidence that this naturally occurring pattern of inter-strain variation in H. influenzae can be mediated by transformation was obtained through sequencing DNA obtained from a pool of 200 independent transformants of a recipient (strain Rd using donor DNA from a heterologous Hib strain (Eagan. Conclusion Much of the inter-strain variation in genome sequence in H. influenzae is likely the result of inter-strain exchanges of DNA, most plausibly through transformation.

  15. Mutations affecting gyrase in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.; Cabrera-Juarez, E.; Albritton, W.L.; Spikes, D.; Mutschler, A.

    1985-11-01

    Mutants separately resistant to novobiocin, coumermycin, nalidixic acid, and oxolinic acid contained gyrase activity as measured in vitro that was resistant to the antibiotics, indicating that the mutations represented structural alterations of the enzyme. One Novr mutant contained an altered B subunit of the enzyme, as judged by the ability of a plasmid, pNov1, containing the mutation to complement a temperature-sensitive gyrase B mutation in Escherichia coli and to cause novobiocin resistance in that strain. Three other Novr mutations did not confer antibiotic resistance to the gyrase but appeared to increase the amount of active enzyme in the cell. One of these, novB1, could only act in cis, whereas a new mutation, novC, could act in trans. An RNA polymerase mutation partially substituted for the novB1 mutation, suggesting that novB1 may be a mutation in a promoter region for the B subunit gene. Growth responses of strains containing various combinations of mutations on plasmids or on the chromosome indicated that low-level resistance to novobiocin or coumermycin may have resulted from multiple copies of wild-type genes coding for the gyrase B subunit, whereas high-level resistance required a structural change in the gyrase B gene and was also dependent on alteration in a regulatory region. When there was mismatch at the novB locus, with the novB1 mutation either on a plasmid or the chromosome, and the corresponding wild-type gene present in trans, chromosome to plasmid recombination during transformation was much higher than when the genes matched, probably because plasmid to chromosome recombination, eliminating the plasmid, was inhibited by the mismatch.

  16. Tipificación capsular mediante PCR de aislamientos de Haemophilus influenzae no tipificables por aglutinación PCR-based capsular typing of Haemophilus influenzae isolates non-typeable by agglutination

    Directory of Open Access Journals (Sweden)

    G. Weltman

    2005-12-01

    Full Text Available Haemophilus influenzae es reconocido como un agente patógeno responsable de infecciones localizadas y sistémicas. Se han descrito 6 tipos de polisacáridos capsulares antigénicamente distintos (a, b, c, d, e, y f que se pueden identificar por aglutinación en lámina con antisueros específicos. También existen cepas no capsuladas (NC fenotípicamente no tipificables (NT. La introducción de la vacuna conjugada produjo una marcada disminución de las enfermedades invasivas causadas por H. influenzae tipo b. En este contexto, la tipificación capsular mediante PCR es el método más apropiado para distinguir las cepas no capsuladas de las mutantes b deficientes en cápsula (b- y detectar la presencia de cepas pertenecientes a otros serotipos que no puedan ser tipificables por aglutinación. Se determinó el genotipo capsular a 38 aislamientos de Haemophilus influenzae no tipificables por aglutinación, derivados al servicio de Bacteriología Clínica del INEI-ANLIS "Dr. Carlos G. Malbrán" en el período 2002-2004. El 78,9% de los aislamientos provenían de hemocultivos y la mayor parte de ellos estaban asociados a foco respiratorio. El 100% de los aislamientos fueron identificados como H. influenzae no capsulados mediante la técnica de PCR.Haemophilus influenzae is recognized as a pathogenic agent responsible of localized and systemic infections. Six antigenically different capsular polysaccharide types have been described (a, b, c, d, e, and f which can be identified by slide agglutination with specific antisera. Besides there are non capsulated strains that cannot be typed by slide agglutination. The introduction of the conjugated vaccine produced an important reduction of invasive diseases caused by H. influenzae type b. Capsular typing by PCR is the most appropriated method for distinguishing non capsulated strains from capsule deficient type b mutants (b- and for detecting strains of other serotypes that cannot be detected by slide

  17. Aislamiento de distintos serotipos de Haemophilus influenzae en muestras profundas de pacientes pediátricos Isolation of Haemophilus influenzae serotypes from sterile sites in sick children

    Directory of Open Access Journals (Sweden)

    B.M. Gatti

    2004-03-01

    Full Text Available Haemophilus influenzae (Hi es responsable de diversas enfermedades humanas como sepsis, meningitis, celulitis y osteoartritis. En este trabajo se investigó la recuperación de distintos serotipos de Hi en muestras profundas de pacientes pediátricos. Se estudiaron 179 aislamientos de 146 niños durante el periodo 1996-2002 en el Laboratorio de Microbiología del Hospital de Niños Superiora Sor María Ludovica, Argentina. La distribución de los serotipos fue la siguiente: 1 a, 112 b, 1 c,1 d, 4 e, 3 f y 24 no tipificables. A partir del establecimiento de la estrategia de vacunación universal anti Hi b en 1998 se observa una disminución notable del serotipo b y un aumento relativo de otros y no tipificables.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.

  18. Comparison of lipopolysaccharides from Brazilian purpuric fever isolates and conjunctivitis isolates of Haemophilus influenzae biogroup aegyptius. Brazilian Purpuric Fever Study Group.

    OpenAIRE

    Erwin, A L; Munford, R S

    1989-01-01

    Haemophilus influenzae biogroup aegyptius (H. aegyptius) has been identified as the etiologic agent of the recently described disease Brazilian purpuric fever (BPF). Although there is heterogeneity among the strains associated with conjunctivitis, isolates from patients with BPF appear to be derived from a single clone. The clinical presentation of BPF suggests that bacterial lipopolysaccharides (LPS) are involved in its pathogenesis. We prepared LPS from H. influenzae biogroup aegyptius and ...

  19. Gyrase activity and number of copies of the gyrase B subunit gene in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Juarez, E.; Setlow, J.K.

    1985-11-01

    Gyrase activities in extracts of various strains of Haemophilus influenzae can differ by more than an order of magnitude. Measurements of in vitro activity and copy number indicated that most of these differences arose from variations in the number of copies of the gene for the gyrase B subunit, with some strains containing multicopy plasmids coding for that subunit. The quantitative relationship between gyrase and copy number depended on the mutations in the plasmids and in the host. The possibility that the in vivo gyrase activity did not reflect the in vitro data was explored by measurement of alkaline phosphatase and ATPase activity in the extracts. Alkaline phosphatase activity increased with increasing gyrase activity measured in vitro, but ATPase activity did not. The authors conclude that extra supercoiling enhanced transcription of the alkaline phosphatase gene but not the ATPase gene and that it is unlikely that there is much discrepancy between gyrase activity assayed in vitro and the activity in the cell.

  20. [Activity of cefpodoxime and other oral beta-lactams against Haemophilus influenzae and Streptococcus pneumoniae with different susceptibilities to penicillin].

    Science.gov (United States)

    Fenoll, A; Robledo, O; Lerma, M; Giménez, M J; Cebrián, L; Casal, J; Aguilar, L; Gómez-Lus, M L

    2006-03-01

    This study explores the influence on the intrinsic activity of different oral beta-lactams of beta-lactamase production in Haemophilus influenzae and penicillin resistance in Streptococcus pneumoniae. Three substudies were performed: a) a general susceptibility study, analyzing 550 strains received by the Spanish Laboratorio de Referencia de Neumococos throughout February and March 2005; b) a study on the influence of penicillin resistance on the activity of beta-lactams, analyzing 251 penicillin-susceptible strains (MICor=2 mg/l) randomly chosen among those received by the Spanish Laboratorio de Referencia de Neumococos throughout 2005; and c) an H. influenzae susceptibility study analyzing 150 strains received by Instituto Valenciano de Microbiologia throughout 2005. A total of 71% of S. pneumoniae strains were susceptible to penicillin, 21% exhibited intermediate resistance and 8% strains presented full resistance. H. influenzae beta-lactamase production rate was 18.6%. Of the non-beta-lactamase-producing strains, 3% were not susceptible to ampicillin. Cefpodoxime and cefixime exhibited the highest intrinsic activity against H. influenzae, while amoxicillin and cefpodoxime were the most active compounds against S. pneumoniae. All H. influenzae strains were susceptible to oral cephalosporins and amoxicillin/clavulanic acid. The increase in penicillin resistance in S. pneumoniae influenced cefixime, cefaclor and cefuroxime to a higher degree than amoxicillin and cefpodoxime.

  1. Intranasal immunization with nontypeable Haemophilus influenzae outer membrane vesicles induces cross-protective immunity in mice.

    Directory of Open Access Journals (Sweden)

    Sandro Roier

    Full Text Available 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.

  2. Molecular insights of co-trimoxazole resistance genes in Haemophilus influenzae isolated in Malaysia.

    Science.gov (United States)

    Mohd-Zain, Z; Kamsani, N H; Ahmad, N

    2013-12-01

    In the last few decades, co-trimoxazole (SXT), an antibacterial combination of trimethoprim and sulfamethoxazole, has been used for treatment of upper respiratory tract infection due to Haemophilus influenzae. The usage of this antibiotic has become less important due to emergence of SXT-resistant strains worldwide. Most reports associate SXT resistance to the presence of variants of dihydrofolate reductase (DHFR) dfrA genes which are responsible for trimethoprim resistance; while the sulfamethoxazole (SMX) resistance are due to sulfonamide (SUL) genes sul1 and sul2 and/or mutation in the chromosomal (folP) gene encoding dihydropteroate synthetase (DHPS). This study aims to detect and analyse the genes that are involved in SXT resistance in H. influenzae strains that were isolated in Malaysia. Primers targeting for variants of dfrA, fol and sul genes were used to amplify the genes in nine SXT-resistant strains. The products of amplification were sequenced and multiple alignments of the assembled sequences of the local strains were compared to the sequences of other H. influenzae strains in the Genbank. Of the five variants of the dhfA genes, dfrA1 was detected in three out of the nine strains. In contrast to intermediate strains, at least one variant of folP genes was detected in the resistant strains. Multiple nucleotide alignment of this gene revealed that strain H152 was genetically different from the others due to a 15-bp nucleotide insert in folP gene. The sequence of the insert was similar to the insert in folP of H. influenzae strain A12, a strain isolated in United Kingdom. None of the strains had sul1 gene but sul2 gene was detected in four strains. Preliminary study on the limited number of samples shows that the TMP resistance was attributed to mainly to dfrA1 and the SMX was due to folP genes. Presence of sul2 in addition to folP in seven strains apparently had increased their level of resistance. A strain that lacked sul1 or sul2 gene, its resistance

  3. Clinical characteristics of Haemophilus influenzae meningitis in Denmark in the post-vaccination era

    DEFF Research Database (Denmark)

    Pedersen, T.I.; Howitz, M.; Andersen, Christian Østergaard

    2010-01-01

    P>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...

  4. Haemophilus influenzae serotype a septic arthritis in an immunized central Australian indigenous child.

    Science.gov (United States)

    Fischer, Nicholas J

    2014-04-01

    This article describes a notable case of Haemophilus influenzae serotype a (Hia) septic arthritis in an immunized central Australian indigenous child. Since the widespread immunization for H. influenzae serotype b (Hib) in many indigenous peoples worldwide, there has been an increase in reported cases of Hia, postulating that this serotype is taking over the niche that Hib once occupied in indigenous populations.

  5. Clonal relationship of recent invasive Haemophilus influenzae serotype f isolates from Denmark and the United States

    DEFF Research Database (Denmark)

    Bruun, B; Gahrn-Hansen, B; Westh, H;

    2004-01-01

    Surveillance performed after the introduction of general Haemophilus influenzae serotype b (Hib) vaccination in Denmark identified 13 cases of invasive bacteraemic H. influenzae serotype f (Hif) disease in adults over a period of 7 years. Bacteraemic respiratory tract infections accounted for 61...

  6. Enrichment and purification of proteins of Haemophilus influenzae by chromatofocusing.

    Science.gov (United States)

    Fountoulakis, M; Langen, H; Gray, C; Takács, B

    1998-05-15

    Haemophilus influenzae is a bacterium of pharmaceutical interest of which the entire genome has been sequenced. Identification of low-abundance proteins in a two-dimensional map is important for the detection of new drug targets. We applied chromatography on Polybuffer Exchanger (chromatofocusing) in order to fractionate and enrich H. influenzae proteins, possibly low-copy-number gene products, from larger volumes. Two proteins, major ferric iron-binding protein (HI0097) and 5'-nucleotidase (HI0206) were obtained in pure form and hypothetical protein HI0052 was purified to near homogeneity by this single purification step. Four other proteins, aspartate ammonia lyase (HI0534), peptidase D (HI0675), elongation factor Ts (HI0914) and 5-methyltetrahydropteroyltriglutamate methyltransferase (HI1702), were strongly enriched so that chromatography on Polybuffer Exchanger can be used as an initial step for their isolation. Approximately 125 proteins were identified in the fractions collected from the column. Seventy of these were for the first time identified after chromatography on Polybuffer Exchanger. The proteins enriched by the chromatofocusing step include both low-abundance as well as high-copy-number gene products. They do not belong to a single protein class and the majority of them are enzymes with various functions. The results include a list and a two-dimensional map of the proteins enriched by chromatofocusing. They may be useful in the search of drug targets and in the design of purification protocols for the isolation of homologous proteins from related microorganisms.

  7. Copy number of pilus gene clusters in Haemophilus influenzae and variation in the hifE pilin gene.

    Science.gov (United States)

    Read, T D; Satola, S W; Opdyke, J A; Farley, M M

    1998-04-01

    Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius strain F3031 contains two identical copies of a five gene cluster (hifA to hifE) encoding pili similar to well-characterized Hif fimbriae of H. influenzae type b. HifE, the putative pilus tip adhesin of F3031, shares only 40% amino acid sequence similarity with the same molecule from type b strains, whereas the other four proteins have 75 to 95% identity. To determine whether pilus cluster duplication and the hifE(F3031) allele were special features of BPF-associated bacteria, we analyzed a collection of H. influenzae strains by PCR with hifA- and hifE-specific oligonucleotides, by Southern hybridization with a hifC gene probe, and by nucleotide sequencing. The presence of two pilus clusters was limited to some H. influenzae biogroup aegyptius strains. The hifE(F3031) allele was limited to H. influenzae biogroup aegyptius. Two strains contained one copy of hifE(F3031) and one copy of a variant hifE allele. We determined the nucleotide sequences of four hifE genes from H. influenzae biogroup aegyptius and H. influenzae capsule serotypes a and c. The predicted proteins produced by these genes demonstrated only 35 to 70% identity to the three published HifE proteins from nontypeable H. influenzae, serotype b, and BPF strains. The C-terminal third of the molecules implicated in chaperone binding was the most highly conserved region. Three conserved domains in the otherwise highly variable N-terminal putative receptor-binding region of HifE were similar to conserved portions in the N terminus of Neisseria pilus adhesin PilC. We concluded that two pilus clusters and hifE(F3031) were not specific for BPF-causing H. influenzae, and we also identified portions of HifE possibly involved in binding mammalian cell receptors.

  8. Evidence for donor strand complementation in the biogenesis of Haemophilus influenzae haemagglutinating pili.

    Science.gov (United States)

    Krasan, G P; Sauer, F G; Cutter, D; Farley, M M; Gilsdorf, J R; Hultgren, S J; St Geme, J W

    2000-03-01

    Haemophilus influenzae haemagglutinating pili are surface appendages that promote attachment to host cells and facilitate respiratory tract colonization, an essential step in the pathogenesis of disease. In contrast to other well-characterized forms of pili, H. influenzae haemagglutinating pili are two-stranded helical structures. Nevertheless, haemagglutinating pili are assembled by a pathway that involves a periplasmic chaperone and an outer membrane usher, analogous to the prototype pathway involved in the biogenesis of Escherichia coli P pili. In this study, we performed site-directed mutagenesis of the H. influenzae HifB chaperone and HifA major pilus subunit at positions homologous to sites important for chaperone-subunit interactions and subunit oligomerization in P pili. Mutations at putative subunit binding pocket residues in HifB or at the penultimate tyrosine in HifA abolished formation of HifB-HifA periplasmic complexes, whereas mutations at the -14 glycine in HifA had no effect on HifB-HifA interactions but abrogated HifA oligomerization. To define further the constraints of the interaction between HifA and HifB, we examined the interchangeability of pilus gene cluster components from H. influenzae type b strain Eagan (hifA-hifEEag) and the related H. influenzae biogroup aegyptius strain F3031 (hifA-hifEF3031). Functional pili were assembled both with HifAEag and the strain F3031 gene cluster and with HifAF3031 and the strain Eagan gene cluster, underscoring the flexibility of the H. influenzae chaperone/usher pathway in incorporating HifA subunits with significant sequence diversity. To gain additional insight into the interactive surfaces of HifA and HifB, we aligned HifA sequences from 20 different strains and then modelled the HifA structure based on the recently crystallized PapD-PapK complex. Analysis of the resulting structure revealed high levels of sequence conservation in regions predicted to interact with HifB, and maximal sequence diversity

  9. Distinct antigenic and genetic properties of the immunoglobulin A1 protease produced by Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever in Brazil.

    Science.gov (United States)

    Lomholt, H; Kilian, M

    1995-11-01

    All examined Haemophilus influenzae biogroup aegyptius isolates of the clone associated with Brazilian purpuric fever (the BPF clone) produced type 2 immunoglobulin A1 (IgA1) proteases encoded by identical iga genes that were distinct from the iga genes of other Brazilian H. influenzae biogroup aegyptius isolates. A partial nucleotide sequence analysis revealed close similarities to the iga genes of H. influenzae serotype c and one noncapsular H. influenzae biotype III strain isolated from a case of conjunctivitis in Tunisia, suggesting an evolutionary relationship. Epitopes recognized by neutralizing antibodies differed for the IgA1 proteases of the BPF clone and of other H. influenzae strains, including Brazilian H. influenzae biogroup aegyptius isolates from patients with noninvasive conjunctivitis. The low probability of developing cross-reacting neutralizing antibodies to the IgA1 protease of the BPF clone may contribute to the pathogenic potential of this virulent phenotype in Brazil.

  10. Characterization of lactate utilization and its implication on the physiology of Haemophilus influenzae.

    Science.gov (United States)

    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.

  11. Fur and iron transport proteins in the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Smoot, L M; Bell, E C; Crosa, J H; Actis, L A

    1999-07-01

    The Brazilian purpuric fever (BPF) clone of Haemophilus influenzae biogroup aegyptius causes a fatal septicaemic disease, resembling fulminant meningococcal sepsis, in children. When isolate F3031 was grown under iron-limiting conditions, the presence of several iron-regulated proteins of 38-110 kDa was revealed by electrophoretic analysis and a Fur homologue was shown by immunoblotting. Dot-blot assays and immunoblotting indicated that BPF cells bound human transferrin and contained transferrin-binding proteins in the outer membrane. However, the binding activity and the biosynthesis of these proteins were detected even under iron-rich conditions. Immunoblot analysis demonstrated the presence of a periplasmic protein related to the ferric iron-binding protein A (FbpA), the major iron-binding protein described in Neisseria spp. However, the FbpA homologue in strain F3031 was constitutively expressed and was smaller than the periplasmic protein detected in H. influenzae type b strain Eagan. The periplasm of strain F3031 also contained a protein related to the Streptococcus parasanguis FimA protein which recently has been shown to be involved in iron acquisition in Yersinia pestis. Although the Eagan and F3031 FimA homologues had a similar mol. wt, of 31 kDa, the expression of the BPF fimA-like gene was not regulated by the iron concentration of the culture medium.

  12. Evolution of the paralogous hap and iga genes in Haemophilus influenzae: evidence for a conserved hap pseudogene associated with microcolony formation in the recently diverged Haemophilus aegyptius and H. influenzae biogroup aegyptius.

    Science.gov (United States)

    Kilian, Mogens; Poulsen, Knud; Lomholt, Hans

    2002-12-01

    Certain non-capsulate strains belonging to the Haemophilus influenzae/Haemophilus aegyptius complex show unusually high pathogenicity, but the evolutionary origin of these virulent phenotypes, termed H. influenzae biogroup aegyptius, is as yet unknown. The aim of the present study was to elucidate the mechanisms of evolution of two paralogous genes, hap and iga, which encode the adhesion and penetration Hap protein and the IgA1 protease respectively. Partial sequencing of hap and iga genes in a comprehensive collection of strains belonging to the H. influenzae/H. aegyptius complex revealed considerable genetic polymorphism and pronounced mosaic-like patterns in both genes, but no evidence of intrastrain recombination between the two genes. A conserved hap pseudogene was present in all strains of H. aegyptius and H. influenzae biogroup aegyptius, each of which constituted distinct subpopulations as revealed by phylogenetic analysis. There was no evidence for a second, functional copy of the hap gene in these strains. The perturbed expression of the Hap serine protease appears to be associated with the formation of elongated bacterial cells growing in chains and a distinct colonization pattern on conjunctival cells, previously termed microcolony formation. The fact that individual hap pseudogenes differed from the ancestral sequence by zero to two positions within a 1.5 kb stretch suggests that the silencing event happened approximately 2000-11,000 years ago. Divergence of H. aegyptius and H. influenzae biogroup aegyptius occurred subsequent to this genetic event. The loss of Hap protein expression may be one of the genetic events that facilitated exploitation of the conjunctivae as a new niche.

  13. The capsule biosynthesis locus of Haemophilus influenzae shows conspicuous similarity to the corresponding locus in Haemophilus sputorum and may have been recruited from this species by horizontal gene transfer.

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    Nielsen, Signe M; de Gier, Camilla; Dimopoulou, Chrysoula; Gupta, Vikas; Hansen, Lars H; Nørskov-Lauritsen, Niels

    2015-06-01

    The newly described species Haemophilus sputorum has been cultured from the upper respiratory tract of humans and appears to have little pathogenic potential. The species encodes a capsular biosynthesis locus of approximately 12  kb composed of three distinct regions. Region I and III genes, involved in export and processing of the capsular material, show high similarity to the corresponding genes in capsulate lineages of the pathogenic species Haemophilus influenzae; indeed, standard bexA and bexB PCRs for detection of capsulated strains of H. influenzae give positive results with strains of H. sputorum. Three ORFs are present in region II of the sequenced strain of H. sputorum, of which a putative phosphotransferase showed homology with corresponding genes from H. influenzae serotype c and f. Phylogenetic analysis of housekeeping genes from 24 Pasteurellaceae species showed that H. sputorum was only distantly related to H. influenzae. In contrast to H. influenzae, the capsule locus in H. sputorum is not associated with transposases or other transposable elements. Our data suggest that the capsule locus of capsulate lineages of H. influenzae may have been recruited relatively recently from the commensal species H. sputorum by horizontal gene transfer.

  14. Cloning and sequence analysis of the structural pilin gene of Brazilian purpuric fever-associated Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Whitney, A M; Farley, M M

    1993-04-01

    We have cloned and sequenced the Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius (Hae) pilin gene. The sequence contained a 648-bp open reading frame encoding a mature pilin protein of 191 amino acids with a calculated mass of 20.5 kDa. There was 82% homology between the open reading frames of the BPF strain F3031 and H. influenzae type b (Hib) (strain M43) pilin genes and 71% homology at the amino acid level between the mature pilin proteins. However, areas of diversity were noted throughout the gene. A 17-bp probe corresponding to an area of diversity in the N-terminal region of the BPF-associated gene hybridized with other BPF strains but not with non-BPF Hae or Hib. In summary, the pilin protein of BPF-associated Hae is highly homologous to Hib pilin yet remains structurally distinct.

  15. Role of lipooligosaccharide in virulence of the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius for infant rats.

    Science.gov (United States)

    Rubin, L G; St Geme, J W

    1993-02-01

    Clonally related strains of Haemophilus influenzae biogroup aegyptius have recently been associated with Brazilian purpuric fever (BPF), a fulminant, systemic disease in children. Using an infant rat bacteremia model for BPF, we found that a rat blood-passaged BPF isolate of H. influenzae biogroup aegyptius was more virulent than the original strain was. When compared with the original strain, the animal-passaged variant was found to display an altered lipooligosaccharide (LOS) phenotype and to lack pili. To examine the role of LOS phenotype and pili in virulence, we isolated isogenic variants differing in LOS phenotype or expression of pili. The virulence of variants was compared by examining the results of blood cultures obtained 24 h after intraperitoneal inoculation with 10(5) CFU. Our results indicate that the LOS phenotype is a critical determinant of BPF clone virulence for infant rats. To a lesser extent, the absence of piliation and an undefined additional factor(s) contribute to virulence.

  16. Non-Typeable Haemophilus influenzae Infection of the Junbo Mouse.

    Science.gov (United States)

    Cheeseman, Michael T; Hood, Derek W

    2017-03-02

    Acute otitis media, inflammation of the middle ear bulla, is the most common bacterial infection in children. For one of the principal otopathogens, non-typeable Haemophilus influenzae (NTHi), animal models allow us to investigate host-microbial interactions relevant to the onset and progression of infection and to study treatment of middle ear disease. We have established a robust model of NTHi middle ear infection in the Junbo mouse. Intranasal inoculation with NTHi produces high rates of bulla infection and high bacterial titers in bulla fluids; bacteria can also spread down the respiratory tract to the mouse lung. An innate immune response is detected in the bulla of Junbo mice following NTHi infection, and bacteria are maintained in some ears at least up to day 56 post-inoculation. The Junbo/NTHi infection model facilitates studies on bacterial pathogenesis and antimicrobial intervention regimens and vaccines for better treatment and prevention of NTHi middle ear infection. © 2017 by John Wiley & Sons, Inc.

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

    Science.gov (United States)

    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.

  18. Mutation induction by MNNG in a bacteriophage of Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Boling, M.E.; Kimball, R.F.

    1976-01-01

    Three temperature-sensitive mutants of the haemophilus influenza phage HP1c1 were tested for reversion to wild type (ts ..-->.. ts/sup +/). Treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) produced revertants at levels up to 0.1% of the total progeny phage from treated lysogens. Cells treated with MNNG after infection with whole ts phage produced progeny phage with similar reversion frequencies, but when the uninfected cells or the phage were treated alone no reversion was induced. Fixation of premutational lesions was shown to occur with no evidence for host-cell DNA synthesis, indicating that phage DNA synthesis may be responsible for fixation of mutation in phage DNA. Evidence is given which shows that prophage DNA replicating by the cells' replicating system after treatment and before induction, produces the same number of revertants per survivor as phage DNA which is replicated outside the host genome. Two of the phage mutants (ts1 and ts2) reverted at similar frequencies, while one of the mutants (ts3) exhibited a much lower induced reversion frequency.

  19. The role of cytomegalovirus, Haemophilus influenzae and Epstein Barr virus in Guillain Barre syndrome.

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    Shahriar Nafissi

    2013-06-01

    Full Text Available Guillain Barre Syndrome (GBS is an inflammatory, usually demyelinating, polyneuropathy; clinically characterized by acute onset of symmetric progressive muscle weakness with loss of myotatic reflexes. Thirty five patients with GBS, defined clinically according to the criteria of Asbury and Cornblath, were recruited from three hospital affiliated to Tehran University of Medical Sciences.As a control group 35 age and sex matched patients with other neurological diseases admitted to the same hospital at the same time, were included in our study. Serum samples were collected before treatment from each patient (within 4 weeks after the disease onset and controls, and stored frozen at -80ºC until serologic assays were done. Serologic testing of pretreatment serum was performed in all patients. Positive titer of virus specific IgM antibody against cytomegalovirus (CMV was found in 6 cases and 2 controls. 34 patients and 31 controls had high titer of anti Haemophilus influenzae IgG and one patient had serologic evidence of a recent Epstein Barr virus (EBV infection. The mean titer of IgG antibody against Haemophilus influenzae in cases and controls was 5.21 and 2.97 respectively. Although serologic evidence of all these infections were more frequent in cases than in controls, only Haemophilus influenzae infection appeared to be significantly related to GBS (P=0.002. Eleven cases and 3 controls had high titers of IgG antibody against Haemophilus influenzae type B (titer >8. There is significant association between high titer of IgG antibody against Haemophilus influenzae and GBS (P=0.017. Our results provide further evidence that Haemophilus influenzae and probably CMV, can be associated with GBS.

  20. Cloning and sequencing of a genomic island found in the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    McGillivary, Glen; Tomaras, Andrew P; Rhodes, Eric R; Actis, Luis A

    2005-04-01

    A genomic island was identified in the Haemophilus influenzae biogroup aegyptius Brazilian purpuric fever (BPF) strain F3031. This island, which was also found in other BPF isolates, could not be detected in non-BPF biogroup aegyptius strains or in nontypeable or typeable H. influenzae strains, with the exception of a region present in the type b Eagan strain. This 34,378-bp island is inserted, in reference to H. influenzae Rd KW20, within a choline transport gene and contains a mosaic structure of Mu-like prophage genes, several hypothetical genes, and genes potentially encoding an Erwinia carotovora carotovoricin Er-like bacteriocin. The product of the tail fiber ORF in the bacteriocin-like region shows a hybrid structure where the C terminus is similar to an H. influenzae phage HP1 tail protein implicating this open reading frame in altering host specificity for a putative bacteriocin. Significant synteny is seen in the entire genomic island with genomic regions from Salmonella enterica subsp. enterica serovar Typhi CT18, Photorhabdus luminescens subsp. laumondii TT01, Chromobacterium violaceum, and to a lesser extent Haemophilus ducreyi 35000HP. In a previous work, we isolated several BPF-specific DNA fragments through a genome subtraction procedure, and we have found that a majority of these fragments map to this locus. In addition, several subtracted fragments generated from an independent laboratory by using different but related strains also map to this island. These findings underscore the importance of this BPF-specific chromosomal region in explaining some of the genomic differences between highly invasive BPF strains and non-BPF isolates of biogroup aegyptius.

  1. Effect of Fluoroquinolones and Macrolides on Eradication and Resistance of Haemophilus influenzae in Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Pettigrew, Melinda M; Tsuji, Brian T; Gent, Janneane F; Kong, Yong; Holden, Patricia N; Sethi, Sanjay; Murphy, Timothy F

    2016-07-01

    Little is known about the effect of antibiotics on eradication of carriage and development of resistance in Haemophilus influenzae in individuals with chronic obstructive pulmonary disease (COPD). Our goals were to assess antibiotic susceptibilities, prevalence of resistance genes, and development of resistance in H. influenzae and to evaluate the effect of macrolide and fluoroquinolone administration on H. influenzae eradication. Data were from a 15-year longitudinal study of COPD. Genome sequence data were used to determine genotype and identify resistance genes. MICs of antibiotics were determined by reference broth microdilution. Generalized linear mixed models were used to evaluate associations between antibiotic use and H. influenzae eradication. We examined 267 H. influenzae isolates from 77 individuals. All newly acquired H. influenzae isolates were susceptible to azithromycin. Five of 27 (19%) strains developed 4-fold increases in azithromycin MICs and reached or exceeded the susceptibility breakpoint (≤4 μg/ml) during exposure. H. influenzae isolates were uniformly susceptible to ciprofloxacin, levofloxacin, and moxifloxacin (MIC90s of 0.015, 0.015, and 0.06, respectively); there were no mutations in quinolone resistance-determining regions. Fluoroquinolone administration was associated with increased H. influenzae eradication compared to macrolides (odds ratio [OR], 16.67; 95% confidence interval [CI], 2.67 to 104.09). There was no difference in H. influenzae eradication when comparing macrolide administration to no antibiotic (OR, 1.89; 95% CI, 0.43 to 8.30). Fluoroquinolones are effective in eradicating H. influenzae in individuals with COPD. Macrolides are ineffective in eradicating H. influenzae, and their use in COPD patients may lead to decreased macrolide susceptibility and resistance.

  2. Isolation, expression, and nucleotide sequencing of the pilin structural gene of the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    St Geme, J W; Falkow, S

    1993-05-01

    In this study we isolated the pilin gene from the Brazilian purpuric fever (BPF) clone of Haemophilus influenzae biogroup aegyptius, expressed the gene in Escherichia coli, and determined its nucleotide sequence. Comparison of the nucleotide sequence of the BPF pilin gene with the sequences of pilin genes from strains of H. influenzae sensu stricto demonstrated a high degree of identity. Consistent with this observation, hemagglutination inhibition studies performed with a series of glycoconjugates indicated that BPF pili and H. influenzae type b pili possess the same erythrocyte receptor specificity.

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

    Science.gov (United States)

    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.

  4. Improvement of Large-scale PRP production by Haemophilus influenzae typeb, using modified CY medium

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    Farshad Nojoomi

    2012-02-01

    Full Text Available Background and Objective: Haemophilus influenzae type b (Hib is a gram negative bacterium and one of the most common causative agents of acute meningitis in infants and less than 5 years old children worldwide. The production of Hib capsular polysaccharide; polyribosyl ribitolphosphate (PRP is important for the production of conjugate vaccines against Hib infections. The aim of this study is the improvement of Large-scale PRP production by Hib. Materials and Methods: Haemophilus influenzae type b standard strain ATCC10211 was cultivated in 2L fermentors contain 1.5L CY (casaminoacid yeast extract medium with normal or modified concentrations of glucose, yeast extract, hemin and NAD (nicotinamide adenine dinucleotide. Seed culture of two fermentors was inoculated to 50 L fermentor, separately and range of PRP production and Dry cell weight (DCW were studied. Results: Cultivation of Hib in 50L fermentor contained modified CY medium with 6gl-1 Glucose, 2.5 gl-1 Yeast extract, 0.03 gl-1 Hemin and 0.015 gl-1 NAD , with controlled pH at 7.3 and 30% Dissolved oxygen tension (DOT resulted to about 5.1 gl-1 DCW and 1.16 gl-1 PRP , that was significantly higher than normal CY medium. Conclusion: In conclusion, by modification in some medium components of CY medium, control of Dissolved oxygen tension and pH, the Large-scale production of PRP is improved. Improvement of PRP production leads to reduce the final cost of Hib conjugate vaccines.

  5. Special type of UV-stimulated recombination in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Waldstein, E; Setlow, J K; Santasier, L

    Following uv irradiation, the DNA of wild type H. influenzae undergoes extensive exchange between strands synthesized before and after irradiation. There are apparently many more exchanges than uv-induced pyrimidine dimers, unlike the situation in Esherichia coli. Such uv-induced exchange does not take place in the highly recombination-defective rec1 strain of H. influenzae, but is extensive in the even more recombination-defective rec2 strain. These events are correlated with the filling of the single-strand gaps made in DNA synthesized after uv; in rec2 the gaps are filled normally, but there is little or no gapfilling in rec1. Normal DNA replication is not required for gapfilling, since it takes place in a temperature-sensitive DNA synthesis mutant at a temperature restrictive for DNA synthesis. Thus it is probable that in H. influenzae exchange is more important for gapfilling than is de novo synthesis. In order to find out more about uv-induced exchange, we have examined the question of whether dimers originally in DNA synthesized before irradiation could be shifted into the DNA made after irradiation by way of such a mechanism.

  6. Characteristics of Haemophilus influenzae invasive isolates from Portugal following routine childhood vaccination against H. influenzae serotype b (2002-2010).

    Science.gov (United States)

    Bajanca-Lavado, M P; Simões, A S; Betencourt, C R; Sá-Leão, R

    2014-04-01

    We aimed to characterize Haemophilus influenzae invasive isolates recovered in Portugal over a 9-year period (2002-2010) following the inclusion of H. influenzae serotype b (Hib) conjugate vaccination in the National Immunization Program (NIP) in the year 2000 and compare the results with those obtained in a similar study from the pre-vaccination era (1989-2001) previously described by us. As part of a laboratory-based passive surveillance system, 144 invasive isolates obtained in 28 Portuguese hospitals were received at the National Reference Laboratory for Bacterial Respiratory Infections and were characterized. Capsular types and antibiotic susceptibility patterns were determined. The ftsI gene encoding PBP3 was sequenced for β-lactamase-negative ampicillin-resistant (BLNAR) isolates. Genetic relatedness among isolates was examined by multilocus sequencing typing (MLST). Most isolates (77.1%) were non-capsulated, a significant increase compared to the pre-vaccination era (19.0%, p < 0.001). Serotype b strains decreased significantly (from 81.0 to 13.2%, p < 0.001) and serotype f increased significantly (from 0.8 to 6.9%, p = 0.03). Ten percent of the isolates were β-lactamase producers, a value lower than that previously observed (26.9%, p = 0.005). Eight percent of all isolates were BLNAR. A high genetic diversity among non-capsulated isolates was found. By contrast, capsulated isolates were clonal. The implementation of Hib vaccination has resulted in a significant decline in the proportion of serotype b H. influenzae invasive disease isolates. Most episodes of invasive disease occurring in Portugal are now due to fully susceptible, highly diverse, non-capsulated strains. Given the evolving dynamics of this pathogen and the increase in non-type b capsulated isolates, continuous surveillance is needed.

  7. In vitro activity of telithromycin against Haemophilus influenzae at epithelial lining fluid concentrations

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    Drago Lorenzo

    2008-01-01

    Full Text Available Abstract Background Haemophilus influenzae is one of the main aetiological agents of community-acquired respiratory tract infections. The primary aim of this study was to evaluate the antibacterial activity of telithromycin against H. influenzae clinical isolates showing different pattern of resistance in comparison with azithromycin and clarithromycin at 1/4 ×, 1/2 ×, 1 ×, 2 ×, 4 × minimum inhibitory concentration (MIC and to peak concentrations in epithelial lining fluid (ELF. The secondary aim was to determine the influence of CO2 enriched atmosphere on bacterial susceptibility. Results Telithromycin showed high activity against H. influenzae, including strains susceptible to β-lactams (n = 200, β-lactamase producer (n = 50 and β-lactamase negative ampicillin resistant (BLNAR (n = 10, with MIC from ≤0.03 to 4 mg/L, and MIC50/MIC90 of 1/2 mg/L with susceptibility rate of 100%, and minimum bactericidal concentrations (MBC from 2 to 4-fold higher than the MIC. Azithromycin was the most active tested macrolide (range: 0.25 – 4 mg/L; MIC50/MIC90: 1/2 mg/L, comparable to telithromycin, while clarithromycin showed the highest MICs and MBCs (range: 0.25 – 8 mg/L; MIC50/MIC90: 2/8 mg/L. In time-kill studies, telithromycin showed a bactericidal activity at the higher concentrations (4 – 2 × MIC and ELF against all the strains, being complete after 12 – 24 hours from drug exposition. At MIC concentrations, at ambient air, bactericidal activity of telithromycin and azithromycin was quite similar at 12 hours, and better than that of clarithromycin. Besides, telithromycin and clarithromycin at ELF concentrations were bactericidal after 12 hours of incubation for most strains, while 24 hours were needed to azithromycin to be bactericidal. Incubation in CO2 significantly influenced the MICs and MBCs, and only slightly the in vitro killing curves. Conclusion Telithromycin showed an in-vitro potency against H. influenzae comparable to

  8. Characterisation and genetic organisation of a 24-MDa plasmid from the Brazilian Purpuric Fever clone of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Kroll, J S; Farrant, J L; Tyler, S; Coulthart, M B; Langford, P R

    2002-07-01

    Strains of Haemophilus influenzae biogroup aegyptius causing septicaemia were identified in Brazil in the 1980s, causing the life-threatening illness of Brazilian Purpuric Fever (BPF). The strains were found to fall into a single clonal group, the BPF clone, characterised by their possession of the approximately 24MDa "3031" plasmid. In this work we report the characterisation and genetic organisation of this plasmid. Analysis of the gene content of what appears to be a typical broad host range conjugative plasmid, its presence in non-BPF strains as revealed by Southern hybridisation, and the recent discovery of plasmid-lacking BPF strains, has led us to conclude that it is unlikely to play a critical role in bacterial virulence. Establishing its entire sequence has nonetheless been an important step on the road to delineating, by comparison of BPF and non-BPF strains, chromosomal genetic loci that are involved in the special virulence of the BPF clone.

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

    Science.gov (United States)

    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.

  10. A functional tonB gene is required for both virulence and competitive fitness in a chinchilla model of Haemophilus influenzae otitis media.

    Science.gov (United States)

    Morton, Daniel J; Hempel, Randy J; Seale, Thomas W; Whitby, Paul W; Stull, Terrence L

    2012-06-25

    Haemophilus influenzae requires heme for aerobic growth and possesses multiple mechanisms to obtain this essential nutrient. An insertional mutation in tonB was constructed and the impact of the mutation on virulence and fitness in a chinchilla model of otitis media was determined. The tonB insertion mutant strain was significantly impacted in both virulence and fitness as compared to the wildtype strain in this model. The tonB gene of H. influenzae is required for the establishment and maintenance of middle ear infection in this chinchilla model of bacterial disease.

  11. A functional tonB gene is required for both virulence and competitive fitness in a chinchilla model of Haemophilus influenzae otitis media

    Directory of Open Access Journals (Sweden)

    Morton Daniel J

    2012-06-01

    Full Text Available Abstract Background Haemophilus influenzae requires heme for aerobic growth and possesses multiple mechanisms to obtain this essential nutrient. Methods An insertional mutation in tonB was constructed and the impact of the mutation on virulence and fitness in a chinchilla model of otitis media was determined. The tonB insertion mutant strain was significantly impacted in both virulence and fitness as compared to the wildtype strain in this model. Conclusions The tonB gene of H. influenzae is required for the establishment and maintenance of middle ear infection in this chinchilla model of bacterial disease.

  12. Susceptibilities of Haemophilus influenzae and Moraxella catarrhalis to ABT-773 compared to their susceptibilities to 11 other agents.

    Science.gov (United States)

    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-macrolide-azalide group for all strains tested.

  13. Serum resistance and phase variation of a nasopharyngeal non-typeable Haemophilus influenzae isolate.

    Science.gov (United States)

    Lichtenegger, Sabine; Bina, Isabelle; Durakovic, Sanel; Glaser, Philippe; Tutz, Sarah; Schild, Stefan; Reidl, Joachim

    2017-02-01

    Haemophilus influenzae harbours a complex array of factors to resist human complement attack. As non-typeable H. influenzae (NTHi) strains do not possess a capsule, their serum resistance mainly depends on other mechanisms including LOS decoration. In this report, we describe the identification of a highly serum resistant, nasopharyngeal isolate (NTHi23) by screening a collection of 77 clinical isolates. For NTHi23, we defined the MLST sequence type 1133, which matches the profile of a previously published invasive NTHi isolate. A detailed genetic analysis revealed that NTHi23 shares several complement evading mechanisms with invasive disease isolates. These mechanisms include the functional expression of a retrograde phospholipid trafficking system and the presumable decoration of the LOS structure with sialic acid. By screening the NTHi23 population for spontaneous decreased serum resistance, we identified a clone, which was about 10(3)-fold more sensitive to complement-mediated killing. Genome-wide analysis of this isolate revealed a phase variation in the N'-terminal region of lpsA, leading to a truncated version of the glycosyltransferase (LpsA). We further showed that a NTHi23 lpsA mutant exhibits a decreased invasion rate into human alveolar basal epithelial cells. Since only a small proportion of the NTHi23 population expressed the serum sensitive phenotype, resulting from lpsA phase-off, we conclude that the nasopharyngeal environment selected for a population expressing the intact and functional glycosyltransferase.

  14. Subinhibitory concentrations of azithromycin decrease nontypeable Haemophilus influenzae biofilm formation and Diminish established biofilms.

    Science.gov (United States)

    Starner, Timothy D; Shrout, Joshua D; Parsek, Matthew R; Appelbaum, Peter C; Kim, GunHee

    2008-01-01

    Nontypeable Haemophilus influenzae (NTHi) commonly causes otitis media, chronic bronchitis in emphysema, and early airway infections in cystic fibrosis. Long-term, low-dose azithromycin has been shown to improve clinical outcomes in chronic lung diseases, although the mechanism of action remains unclear. The inhibition of bacterial biofilms by azithromycin has been postulated to be one mechanism mediating these effects. We hypothesized that subinhibitory concentrations of azithromycin would affect NTHi biofilm formation. Laboratory strains of NTHi expressing green fluorescent protein and azithromycin-resistant clinical isolates were grown in flow-cell and static-culture biofilm models. Using a range of concentrations of azithromycin and gentamicin, we measured the degree to which these antibiotics inhibited biofilm formation and persistence. Large biofilms formed over 2 to 4 days in a flow cell, displaying complex structures, including towers and channels. Subinhibitory concentrations of azithromycin significantly decreased biomass and maximal thickness in both forming and established NTHi biofilms. In contrast, subinhibitory concentrations of gentamicin had no effect on biofilm formation. Furthermore, established NTHi biofilms became resistant to gentamicin at concentrations far above the MIC. Biofilm formation of highly resistant clinical NTHi isolates (azithromycin MIC of > 64 microg/ml) was similarly decreased at subinhibitory azithromycin concentrations. Clinically obtainable azithromycin concentrations inhibited biofilms in all but the most highly resistant isolates. These data show that subinhibitory concentrations of azithromycin have antibiofilm properties, provide mechanistic insights, and supply an additional rationale for the use of azithromycin in chronic biofilm infections involving H. influenzae.

  15. Laboratory characterization of invasive Haemophilus influenzae isolates from Nunavut, Canada, 2000–2012

    Directory of Open Access Journals (Sweden)

    Raymond S. W. Tsang

    2016-01-01

    Full Text Available Background: With invasive Haemophilus influenzae serotype b (Hib disease controlled by vaccination with conjugate Hib vaccines, there is concern that invasive disease due to non-serotype b strains may emerge. Objective: This study characterized invasive H. influenzae (Hi isolates from Nunavut, Canada, in the post-Hib vaccine era. Methods: Invasive H. influenzae isolates were identified by conventional methods at local hospitals; and further characterized at the provincial and federal public health laboratories, including detection of serotype antigens and genes, multi-locus sequence typing and antibiotic susceptibility. Results: Of the 89 invasive H. influenzae cases identified from 2000 to 2012, 71 case isolates were available for study. There were 43 serotype a (Hia, 12 Hib, 2 Hic, 1 Hid, 1 Hie, 2 Hif and 10 were non-typeable (NT. All 43 Hia were biotype II, sequence type (ST-23. Three related STs were found among the Hib isolates: ST-95 (n=9, ST-635 (n=2 and ST-44 (n=1. Both Hif belonged to ST-124 and the 2 Hic were typed as ST-9. The remaining Hid (ST-1288 and Hie (ST-18 belonged to 2 separate clones. Of the 10 NT strains, 3 were typed as ST-23 and the remaining 7 isolates each belonged to a unique ST. Eight Hib and 1 NT-Hi were found to be resistant to ampicillin due to β-lactamase production. No resistance to other antibiotics was detected. Conclusion: During the period of 2000–2012, Hia was the predominant serotype causing invasive disease in Nunavut. This presents a public health concern due to an emerging clone of Hia as a cause of invasive H. influenzae disease and the lack of published guidelines for the prophylaxis of contacts. The clonal nature of Hia could be the result of spread within an isolated population, and/or unique characteristics of this strain to cause invasive disease. Further study of Hia in other populations may provide important information on this emerging pathogen. No antibiotic resistance was detected among Hia

  16. Laboratory characterization of invasive Haemophilus influenzae isolates from Nunavut, Canada, 2000-2012.

    Science.gov (United States)

    Tsang, Raymond S W; Li, Y Anita; Mullen, Angie; Baikie, Maureen; Whyte, Kathleen; Shuel, Michelle; Tyrrell, Gregory; Rotondo, Jenny A L; Desai, Shalini; Spika, John

    2016-01-01

    With invasive Haemophilus influenzae serotype b (Hib) disease controlled by vaccination with conjugate Hib vaccines, there is concern that invasive disease due to non-serotype b strains may emerge. This study characterized invasive H. influenzae (Hi) isolates from Nunavut, Canada, in the post-Hib vaccine era. Invasive H. influenzae isolates were identified by conventional methods at local hospitals; and further characterized at the provincial and federal public health laboratories, including detection of serotype antigens and genes, multi-locus sequence typing and antibiotic susceptibility. Of the 89 invasive H. influenzae cases identified from 2000 to 2012, 71 case isolates were available for study. There were 43 serotype a (Hia), 12 Hib, 2 Hic, 1 Hid, 1 Hie, 2 Hif and 10 were non-typeable (NT). All 43 Hia were biotype II, sequence type (ST)-23. Three related STs were found among the Hib isolates: ST-95 (n=9), ST-635 (n=2) and ST-44 (n=1). Both Hif belonged to ST-124 and the 2 Hic were typed as ST-9. The remaining Hid (ST-1288) and Hie (ST-18) belonged to 2 separate clones. Of the 10 NT strains, 3 were typed as ST-23 and the remaining 7 isolates each belonged to a unique ST. Eight Hib and 1 NT-Hi were found to be resistant to ampicillin due to β-lactamase production. No resistance to other antibiotics was detected. During the period of 2000-2012, Hia was the predominant serotype causing invasive disease in Nunavut. This presents a public health concern due to an emerging clone of Hia as a cause of invasive H. influenzae disease and the lack of published guidelines for the prophylaxis of contacts. The clonal nature of Hia could be the result of spread within an isolated population, and/or unique characteristics of this strain to cause invasive disease. Further study of Hia in other populations may provide important information on this emerging pathogen. No antibiotic resistance was detected among Hia isolates; a small proportion of Hib and NT-Hi isolates

  17. Laboratory characterization of invasive Haemophilus influenzae isolates from Nunavut, Canada, 2000–2012

    Science.gov (United States)

    Tsang, Raymond S. W.; Li, Y. Anita; Mullen, Angie; Baikie, Maureen; Whyte, Kathleen; Shuel, Michelle; Tyrrell, Gregory; Rotondo, Jenny A. L.; Desai, Shalini; Spika, John

    2016-01-01

    Background With invasive Haemophilus influenzae serotype b (Hib) disease controlled by vaccination with conjugate Hib vaccines, there is concern that invasive disease due to non-serotype b strains may emerge. Objective This study characterized invasive H. influenzae (Hi) isolates from Nunavut, Canada, in the post-Hib vaccine era. Methods Invasive H. influenzae isolates were identified by conventional methods at local hospitals; and further characterized at the provincial and federal public health laboratories, including detection of serotype antigens and genes, multi-locus sequence typing and antibiotic susceptibility. Results Of the 89 invasive H. influenzae cases identified from 2000 to 2012, 71 case isolates were available for study. There were 43 serotype a (Hia), 12 Hib, 2 Hic, 1 Hid, 1 Hie, 2 Hif and 10 were non-typeable (NT). All 43 Hia were biotype II, sequence type (ST)-23. Three related STs were found among the Hib isolates: ST-95 (n=9), ST-635 (n=2) and ST-44 (n=1). Both Hif belonged to ST-124 and the 2 Hic were typed as ST-9. The remaining Hid (ST-1288) and Hie (ST-18) belonged to 2 separate clones. Of the 10 NT strains, 3 were typed as ST-23 and the remaining 7 isolates each belonged to a unique ST. Eight Hib and 1 NT-Hi were found to be resistant to ampicillin due to β-lactamase production. No resistance to other antibiotics was detected. Conclusion During the period of 2000–2012, Hia was the predominant serotype causing invasive disease in Nunavut. This presents a public health concern due to an emerging clone of Hia as a cause of invasive H. influenzae disease and the lack of published guidelines for the prophylaxis of contacts. The clonal nature of Hia could be the result of spread within an isolated population, and/or unique characteristics of this strain to cause invasive disease. Further study of Hia in other populations may provide important information on this emerging pathogen. No antibiotic resistance was detected among Hia isolates; a

  18. Conservation and Recombination in the Genome Sequence of Haemophilus influenzae Type f WAPHL1.

    Science.gov (United States)

    Bateman, Allen C; Perez-Osorio, Ailyn C; Li, Zhen; Tran, Michael; Greninger, Alexander L

    2017-09-21

    We report here the second draft genome sequence of a bloodstream isolate of Haemophilus influenzae serotype f. Three discrete 3.1- to 7.8-kb sites contained 80% of the variability in the genome, consistent with recombination in known virulence factors. Copyright © 2017 Bateman et al.

  19. Haemophilus influenzae induces a potentiated increase in guinea-pig pulmonary resistance to histamine

    NARCIS (Netherlands)

    Folkerts, G.; Nijkamp, F.P.

    1985-01-01

    The human respiratory pathogen Haemophilus influenzae (H.i.) induced bronchial hyperreactivity to histamine (1.0–8.0 μg/100 g b.w. i.v.) in vivo in anaesthetized spontaneously breathing guinea-pigs. This hyperreactivity was caused by a potentiated increase in pulmonary resistance. Decreases in dynam

  20. Antibody response to Haemophilus influenzae type b capsular polysaccharide conjugated to tetanus toxoid in preterm infants

    DEFF Research Database (Denmark)

    Kristensen, Kim; Gyhrs, A; Lausen, B

    1996-01-01

    OBJECTIVE: To evaluate the antibody response to a Haemophilus influenzae type b capsular polysaccharide (HibCP) tetanus toxoid (TT) conjugate vaccine (HibCP-TT) in preterm infants. SUBJECTS: Thirty-five healthy preterm infants with gestational ages (GA) from 27 to 36 weeks and birth weights from...

  1. Culture of non-typeable Haemophilus influenzae from the nasopharynx: Not all media are equal.

    Science.gov (United States)

    Harris, Tegan M; Rumaseb, Angela; Beissbarth, Jemima; Barzi, Federica; Leach, Amanda J; Smith-Vaughan, Heidi C

    2017-03-22

    The efficacy of chocolate agar, versus bacitracin, vancomycin, clindamycin, chocolate agar (BVCCA) for the isolation of non-typeable Haemophilus influenzae (NTHi) from nasopharyngeal swabs was determined. BVCCA cultured NTHi from 97.3% of NTHi-positive swabs, compared to 87.1% for chocolate agar. To maximise culture sensitivity, the use of both media is recommended.

  2. Bacterial Lysis through Interference with Peptidoglycan Synthesis Increases Biofilm Formation by Nontypeable Haemophilus influenzae

    NARCIS (Netherlands)

    Marti, S.; Puig, C.; Merlos, A.; Vinas, M.; Jonge, M.I. de; Linares, J.; Ardanuy, C.; Langereis, J.D.

    2017-01-01

    Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that mainly causes otitis media in children and community-acquired pneumonia or exacerbations of chronic obstructive pulmonary disease in adults. A large variety of studies suggest that biofilm formation by NTHi may be an

  3. Evaluation of Haemophilus influenzae Type B Conjugate Vaccine (Meningococcal Protein Conjugate in Canadian Infants

    Directory of Open Access Journals (Sweden)

    David W Scheifele

    1994-01-01

    Full Text Available Objective: To assess adverse effects and immune responses with a three-dose series of Haemophilus influenzae type b meningococcal protein conjugate (PedvaxHIB or Hib.OMP vaccine, including any immunological response alterations from concurrent administration with routine vaccines for infants.

  4. Antimicrobial susceptibility of Haemophilus influenzae in the respiratory tracts of patients with cystic fibrosis

    NARCIS (Netherlands)

    Moller, LVM; Regelink, AG; Grasselier, H; van Alphen, L

    1998-01-01

    We analyzed the antimicrobial susceptibilities of Haemophilus influenzae isolates from 157 sputum specimens prospectively collected from 39 cystic fibrosis (CF) patients during a 2-year study, These isolates were characterized by random amplified polymorphic DNA analysis and major outer membrane pro

  5. Reliability of Haemophilus influenzae biofilm measurement via static method, and determinants of in vitro biofilm production.

    Science.gov (United States)

    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.

  6. Genetic characteristics of Haemophilus influenzae and Streptococcus pneumoniae isolated from children with conjunctivitis-otitis media syndrome.

    Science.gov (United States)

    Sugita, Gen; Hotomi, Muneki; Sugita, Rinya; Kono, Masamitsu; Togawa, Akihisa; Yamauchi, Kazuma; Funaki, Toshinari; Yamanaka, Noboru

    2014-08-01

    Acute conjunctivitis is the most common ocular disorders among children and frequently concomitant with acute otitis media (AOM) as conjunctivitis-otitis syndrome. In this study, we evaluated prevalence of causative pathogens and PCR-based genotypes of Haemophilus influenzae and Streptococcus pneumoniae among children with conjunctivitis-otitis media syndrome. Nontypeable H. influenzae (NTHi) is identified most often at 61.8% in conjunctiva exudates followed by S. pneumoniae at 28.2% and Moraxella catarrhalis at 19.1%. Genetic β-lactamase nonproducing ampicillin resistant (gBLNAR) strains of NTHi and genetic penicillin resistant S. pneumoniae (gPRSP) were identified at 72.1% and at 74.2% among conjunctiva isolates by polymerase chain reaction (PCR), respectively. Pneumococcal strains having either ermB or mefE genes were identified at 93.5% among conjunctiva isolates. The restriction fragment of patterns of 89.7% pairs of H. influenzae isolates and 100% pairs of pneumococcal isolates from conjunctiva exudates, middle ear fluids (MEFs) and nasopharyngeal swabs were identical. In contrast to the previous reports, most prevalent strains from conjunctivitis-otitis media syndrome was BLNAR H. influenzae in this study. The causative pathogen responsible for acute conjunctivitis will be originated from the nasopharynx. In the absence of MEFs one can possibly rely on the nasopharyngeal culture to guide an appropriate treatment.

  7. Drug-resistance and serotype of 807 strains of Haemophilus influenzae%807株流感嗜血杆菌的血清分型及耐药性的研究

    Institute of Scientific and Technical Information of China (English)

    钟天鹰; 迟富丽; 王惠云; 徐飞; 谈华; 陈倩; 胡正

    2008-01-01

    目的 了解南京地区儿童感染流感嗜血杆菌(Haemophilus influenza, Hi)的血清型及抗生素的耐药性.方法 采集南京儿童医院2004年6月至2007年6月20 985份不同种类标本,分离鉴定Hi 807例,玻片凝集法进行血清分型,纸片扩散法(K-B法)进行抗茵药物敏感实验,E-test法测最低抑菌浓度(MIC).结果 807株流感嗜血杆菌,血清分型,不定型(NTHi)47.71%,可分型中f型最多,占可分型36.02%,b型最少,仅占可分型1.66%.K-B法检测抗生素的耐药率,氨苄西林耐药率49.07%.结论 南京地区儿童感染Hi,可分型株中主要血清型以f、a型占多数.氨苄西林的耐药率逐年上升.

  8. [Haemophilus influenzae and parainfluenzae in children. A retrospective study of 52 cases].

    Science.gov (United States)

    Guillot, F; Mory, C; Gire, R; Aït Hamouda, R

    1983-02-01

    Fifty-two children hospitalized in the Pediatric service of a general hospital between January 1978 and December 1979 were found to be infected with Haemophilus influenzae or para-influenzae (43 with H. influenzae and 9 with para-influenzae). Most of these children (34/52) were less than 4 years of age. The localizations of infections were as follow: 5 meningitis with satisfactory resolution except for 1 who developed slight deafness, 1 epiglotitis, 11 pneumonias or bronchopneumonias, 1 arthritis, 10 otitis medias, 6 conjunctivitis, 3 sinusitis, 10 upper airway infections and 1 neonatal infection. On 8 of these cases the patients were felt to be carriers of H. influenzae or para-influenzae, the signs and symptoms beeing not related to these bacteria. These results are compared with those found in the literature.

  9. DNA sequence analysis and restriction fragment length polymorphisms of the P1 gene of Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever.

    Science.gov (United States)

    Reed, R B; Frost, J B; Kort, K; Myers, S D; Lesse, A J

    1996-09-01

    Brazilian purpuric fever (BPF) is a fulminant pediatric disease caused by specific strains of Haemophilus influenzae biogroup aegyptius. A conserved epitope on the P1 protein of strains of H. influenzae biogroup aegyptius is seen on most virulent isolates. The P1 protein from a Brazilian case-clone strain of H. influenzae biogroup aegyptius was analyzed by cloning and sequencing the gene. Three major variable regions are present within the P1 gene of the BPF clone in an architecture similar to that of the previously sequenced P1 genes from H. influenzae. The DNA sequence data of the P1 gene provided information for restriction fragment length polymorphism analyses among strains of H. influenzae biogroup aegyptius. Using PCR for amplification of the P1 gene, we found that AlwI restriction of this gene allowed for a highly accurate segregation of virulent strains of H. influenzae biogroup aegyptius associated with BPF. The strong association of virulent phenotypes with specific AlwI restriction patterns of the P1 gene provides a basis for the convenient and accurate identification of strains of H. influenzae biogroup aegyptius which cause BPF.

  10. Absence of an important vaccine and diagnostic target in carriage- and disease-related nontypeable Haemophilus influenzae.

    Science.gov (United States)

    Smith-Vaughan, Heidi C; Chang, Anne B; Sarovich, Derek S; Marsh, Robyn L; Grimwood, Keith; Leach, Amanda J; Morris, Peter S; Price, Erin P

    2014-02-01

    Nontypeable Haemophilus influenzae (NTHi)-associated disease is a major health problem globally. Whole-genome sequence analysis identified the absence of hpd genes encoding Haemophilus protein D in 3 of 16 phylogenetically distinct NTHi isolates. This novel finding is of potential clinical significance, as protein D and hpd represent important NTHi vaccine antigen and diagnostic targets, respectively.

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

    Science.gov (United States)

    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.

  12. Tracing the evolution of competence in Haemophilus influenzae.

    Directory of Open Access Journals (Sweden)

    Heather Maughan

    Full Text Available Natural competence is the genetically encoded ability of some bacteria to take up DNA from the environment. Although most of the incoming DNA is degraded, occasionally intact homologous fragments can recombine with the chromosome, displacing one resident strand. This potential to use DNA as a source of both nutrients and genetic novelty has important implications for the ecology and evolution of competent bacteria. However, it is not known how frequently competence changes during evolution, or whether non-competent strains can persist for long periods of time. We have previously studied competence in H. influenzae and found that both the amount of DNA taken up and the amount recombined varies extensively between different strains. In addition, several strains are unable to become competent, suggesting that competence has been lost at least once. To investigate how many times competence has increased or decreased during the divergence of these strains, we inferred the evolutionary relationships of strains using the largest datasets currently available. However, despite the use of three datasets and multiple inference methods, few nodes were resolved with high support, perhaps due to extensive mixing by recombination. Tracing the evolution of competence in those clades that were well supported identified changes in DNA uptake and/or transformation in most strains. The recency of these events suggests that competence has changed frequently during evolution but the poor support of basal relationships precludes the determination of whether non-competent strains can persist for long periods of time. In some strains, changes in transformation have occurred that cannot be due to changes in DNA uptake, suggesting that selection can act on transformation independent of DNA uptake.

  13. Identification of Haemophilus influenzae clones associated with invasive disease a decade after introduction of H. influenzae serotype b vaccination in Italy.

    Science.gov (United States)

    Giufrè, Maria; Cardines, Rita; Accogli, Marisa; Pardini, Manuela; Cerquetti, Marina

    2013-08-01

    The introduction of Haemophilus influenzae serotype b (Hib) conjugate vaccines has changed the epidemiology of invasive H. influenzae disease, with a shift in the predominant serotype from Hib to nonencapsulated H. influenzae (ncHi). The objective of this study was to identify the genotypes/clones associated with invasive H. influenzae disease in Italy. Eighty-seven H. influenzae strains isolated in the years 2009 to 2011 within the National Surveillance of Invasive Bacterial Disease program were analyzed. Strains were characterized by serotyping, antimicrobial susceptibility testing, and multilocus sequence typing (MLST). Genetic polymorphisms in the bla(TEM) gene promoter region as well as the occurrence of both adhesin genes (hmwA and hia) and the IgA1 protease-encoding gene (igaB) were also investigated. Of 87 strains, 67 were ncHi and 20 were encapsulated. Eleven strains were β-lactamase positive, harboring the bla(TEM) gene. Most bla(TEM) genes (10/11) were associated with a Pdel promoter region exhibiting a 135-bp deletion; the remaining strain possessed the Pa/Pb overlapping promoter. MLST analysis showed that encapsulated isolates were clonal, with each serotype sharing a few related sequence types (STs). Forty-six different STs were identified among the 67 ncHi strains. Despite this heterogeneity, a group of closely related STs (ST103, ST139, and ST145) encompassed almost 25% of all ncHi strains and 45.5% of the β-lactamase producers carrying the Pdel promoter. These major ST clones were found to be associated with the hmwA gene but not with the igaB gene. To conclude, although the heterogeneity of the ncHi population was confirmed, diffusion of major successful ST clones was documented.

  14. Inhalation of beta 2 agonists impairs the clearance of nontypable Haemophilus influenzae from the murine respiratory tract

    NARCIS (Netherlands)

    Maris, N.A.; Florquin, S.; van 't Veer, C.; de Vos, A.F.; Buurman, W.; Jansen, H.M.; van der Poll, T.

    2006-01-01

    BACKGROUND: Nontypable Haemophilus influenzae (NTHi) is a common bacterial pathogen causing human respiratory tract infections under permissive conditions such as chronic obstructive pulmonary disease. Inhalation of beta2-receptor agonists is a widely used treatment in patients with chronic obstruct

  15. Molecular characterization of fluoroquinolone resistance in nontypeable Haemophilus influenzae clinical isolates.

    Science.gov (United States)

    Puig, Carmen; Tirado-Vélez, José Manuel; Calatayud, Laura; Tubau, Fe; Garmendia, Junkal; Ardanuy, Carmen; Marti, Sara; de la Campa, Adela G; Liñares, Josefina

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHi) is a common cause of respiratory infections in adults, who are frequently treated with fluoroquinolones. The aims of this study were to characterize the genotypes of fluoroquinolone-resistant NTHi isolates and their mechanisms of resistance. Among 7,267 H. influenzae isolates collected from adult patients from 2000 to 2013, 28 (0.39%) were ciprofloxacin resistant according to Clinical and Laboratory Standards Institute (CLSI) criteria. In addition, a nalidixic acid screening during 2010 to 2013 detected five (0.23%) isolates that were ciprofloxacin susceptible but nalidixic acid resistant. Sequencing of their quinolone resistance-determining regions and genotyping by pulse-field gel electrophoresis and multilocus sequence typing of the 25 ciprofloxacin-resistant isolates available and all 5 nalidixic acid-resistant isolates were performed. In the NTHi isolates studied, two mutations producing changes in two GyrA residues (Ser84, Asp88) and/or two ParC residues (Ser84, Glu88) were associated with increased fluoroquinolone MICs. Strains with one or two mutations (n = 15) had ciprofloxacin and levofloxacin MICs of 0.12 to 2 μg/ml, while those with three or more mutations (n = 15) had MICs of 4 to 16 μg/ml. Long persistence of fluoroquinolone-resistant strains was observed in three chronic obstructive pulmonary disease patients. High genetic diversity was observed among fluoroquinolone-resistant NTHi isolates. Although fluoroquinolones are commonly used to treat respiratory infections, the proportion of resistant NTHi isolates remains low. The nalidixic acid disk test is useful for detecting the first changes in GyrA or in GyrA plus ParC among fluoroquinolone-susceptible strains that are at a potential risk for the development of resistance under selective pressure by fluoroquinolone treatment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Serious systemic infection caused by non-encapsulated Haemophilus influenzae biotype III in an adult

    DEFF Research Database (Denmark)

    Lester, Anne; Pedersen, P B

    1991-01-01

    abuser. Cholangitis and acute alcoholic hepatitis were diagnosed simultaneously. The organism was grown from blood and from synovial fluid of the left knee, but several other joints were also affected. The close relationship between H. influenzae biotype III and H. aegyptius is mentioned in view......Haemophilus influenzae is the aetiological agent in less than 1% of septic arthritis cases in adults and most often serotype b is involved. We report here a case of severe systemic infection due to non-encapsulated H. influenzae biotype III in a 40-year-old man, previously healthy although alcohol...

  17. PnuC and the Utilization of the Nicotinamide Riboside Analog 3-Aminopyridine in Haemophilus influenzae

    OpenAIRE

    Sauer, Elizabeta; Merdanovic, Melisa; Price Mortimer, Anne; Bringmann, Gerhard; Reidl, Joachim

    2004-01-01

    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,...

  18. Intra-tracheal Administration of Haemophilus influenzae in Mouse Models to Study Airway Inflammation.

    Science.gov (United States)

    Venuprasad, K; Theivanthiran, Balamayooran; Cantarel, Brandi

    2016-03-02

    Here, we describe a detailed procedure to efficiently and directly deliver Haemophilus influenzae into the lower respiratory tracts of mice. We demonstrate the procedure for preparing H. influenzae inoculum, intra-tracheal instillation of H. influenzae into the lung, collection of broncho-alveolar lavage fluid (BALF), analysis of immune cells in the BALF, and RNA isolation for differential gene expression analysis. This procedure can be used to study the lung inflammatory response to any bacteria, virus or fungi. Direct tracheal instillation is mostly preferred over intranasal or aerosol inhalation procedures because it more efficiently delivers the bacterial inoculum into the lower respiratory tract with less ambiguity.

  19. DNA aptamers for the detection of Haemophilus influenzae type b by cell SELEX.

    Science.gov (United States)

    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.

  20. Oropharyngeal colonization by Haemophilus influenzae in healthy children from Taubaté (São Paulo, prior to the Haemophilus influenzae type b vaccination program in Brazil Colonização da orofaringe de crianças saudáveis de Taubaté (São Paulo por Haemophilus influenzae, antes da introdução da vacina contra Haemophilus influenzae do tipo b no Brasil

    Directory of Open Access Journals (Sweden)

    Lucia Ferro Bricks

    2004-01-01

    Full Text Available Haemophilus influenzae is one of the most important bacterial agents of otitis and sinusitis. H. influenzae type b (Hib is one of the main causes of meningitis, pneumonia, and septicemia in nonvaccinated children under 6 years of age. The aims of this study were to determine the prevalence of H. influenzae and Hib oropharyngeal colonization prior to the onset of the Hib vaccination program in Brazil in previously healthy children and to assess the susceptibility profile of this microorganism to a selected group of antimicrobials that are used to treat acute respiratory infections. METHOD: Cultures of Haemophilus influenzae were made from oropharynx swabs from 987 children under 6 years of age who were enrolled in 29 day-care centers in Taubaté (a city of São Paulo state, Brazil between July and December 1998. RESULTS: The prevalence of H. influenzae carriers was 17.4%, and only 5.5% of the strains were beta-lactamase producers. The prevalence of Hib carriers was high, 7.3% on average (range, 0.0 - 33.3%. CONCLUSIONS: The low prevalence of colonization by penicillin-resistant strains indicates that it is not necessary to substitute ampicilin or amoxicilin to effectively treat otitis and sinusitis caused by H. influenzae in Taubaté.Haemophilus influenzae é um dos mais importantes agentes bacterianos de otites e sinusites. Em crianças menores de seis anos de idade não vacinadas contra o H. influenzae do tipo b (Hib, essa bactéria é uma das principais causadoras de meningite, pneumonia e sepse. O objetivo deste estudo foi determinar a prevalência da colonização da orofaringe de crianças previamente saudáveis por H. influenzae e Hib e avaliar o perfil de suscetibilidade desses microorganismos a um grupo seleto de antimicrobianos, que habitualmente são utilizados para tratar as infecções respiratórias agudas. MÉTODO: Foram colhidos swabs da orofaringe de 987 crianças menores de seis anos de idade que freqüentavam 29 creches da

  1. Emergence of Non-Serotype b Encapsulated Haemophilus influenzae as a Cause of Pediatric Meningitis in Northwestern Ontario

    Directory of Open Access Journals (Sweden)

    Pouya Sadeghi-Aval

    2013-01-01

    Full Text Available Before the introduction of the conjugate vaccine, Haemophilus influenzae serotype b (Hib was the leading cause of bacterial meningitis in children. Although successful in reducing Hib cases, the vaccine confers no protection against other serotypes of H influenzae, such as a (Hia, or f (Hif. The emergence of invasive disease caused by non-Hib in northwestern Ontario (38 cases between 2002 and 2008 with predominance of Hia was previously reported by the authors. At that time, no cases of pediatric meningitis caused by H influenzae were recorded in the region. Continued surveillance identified 12 new cases of invasive non-Hib between January 2009 and July 2011. Among these cases, three young children developed meningitis with severe complications caused by Hia or Hif. The present article describes these cases along with the characteristics of recent H influenzae isolates from the region, (ie, their genetic background and antibiotic sensitivity. The findings point to the clonal nature of circulating Hia strains as well as to an increase in frequency and severity of pediatric invasive H influenzae infections in northwestern Ontario.

  2. Detection of Haemophilus influenzae by multiplex polymerase chain reaction method%多重聚合酶链反应检测流感嗜血杆菌

    Institute of Scientific and Technical Information of China (English)

    田国忠; 邵祝军; 张砺; 李晓静; 朱兵清; 杨亚静; 徐丽; 高源; 王晓蕾

    2008-01-01

    Objective To develop a rapid method for detecting Haemophilus influenzae by multiplex polymerase chain reaction (M-PCR). Methods Primers (Hi) were designed for amplification of p6 gene coding P6 protein of Haemophilus influenzae, which was used to identify Haemophilus influenzae species. Primers (Hi-cap) were designed for amplification of bexA gene which coding capsular polysaccharide (cap) synthesis was used for detecting whether Haemophilus influenzae isolates possess bexA gene relating to cap synthesis. Twelve primers (Hia-Hif) were designed for amplification of cap synthesis gene to identify the cap-type of Haemophilus influenzae. Other relative enteric pathogenic bacteria were amplified by M-PCR to serve as controls. 200 strains isolated from patients were identified.Results from M-PCR were compared to two methods including V and X factors grow requirement test and standard slide agglutination serotyping (SAST). Results The results indicated that the M-PCR assay was high specificity and sensitivity and might be valuable for differential diagnosis of Haemophilus influenzae.The sensitivity of detection was 0. 935 pg. 189 strains out of the 200 belonged to Haemophilus influenzae isolates, and one isolate was cap-type f. An agreement results were seen among the V and X factors grow requirement test, SAST and M-PCR methods. Conclusion M-PCR method showed satisfactory sensitivity, specificity and stability for detecting and identifying Haemophilus influenzae ,and could be used in clinic diagnosis, surveillance and rapid diagnosis for plague of Haemophilus influenzae.%目的 建立检测流感嗜血杆菌的多重聚合酶链反应(M-PCR)方法 .方法 合成扩增流感嗜血杆菌编码P6外膜蛋白基因的引物(Hi),鉴定流感嗜血杆菌种特异性;合成扩增流感嗜血杆菌编码荚膜基因的引物(Hi-cap),鉴定菌株是否具有荚膜;设计并合成6对扩增流感嗜血杆菌不同血清型(荚膜型)编码摹因的引物(Hia-Hif),鉴定菌株的

  3. Identification and Characterization of msf, a Novel Virulence Factor in Haemophilus influenzae.

    Science.gov (United States)

    Kress-Bennett, Jennifer M; Hiller, N Luisa; Eutsey, Rory A; Powell, Evan; Longwell, Mark J; Hillman, Todd; Blackwell, Tenisha; Byers, Barbara; Mell, Joshua C; Post, J Christopher; Hu, Fen Z; Ehrlich, Garth D; Janto, Benjamin A

    2016-01-01

    Haemophilus influenzae is an opportunistic pathogen. The emergence of virulent, non-typeable strains (NTHi) emphasizes the importance of developing new interventional targets. We screened the NTHi supragenome for genes encoding surface-exposed proteins suggestive of immune evasion, identifying a large family containing Sel1-like repeats (SLRs). Clustering identified ten SLR-containing gene subfamilies, each with various numbers of SLRs per gene. Individual strains also had varying numbers of SLR-containing genes from one or more of the subfamilies. Statistical genetic analyses of gene possession among 210 NTHi strains typed as either disease or carriage found a significant association between possession of the SlrVA subfamily (which we have termed, macrophage survival factor, msf) and the disease isolates. The PittII strain contains four chromosomally contiguous msf genes. Deleting all four of these genes (msfA1-4) (KO) resulted in a highly significant decrease in phagocytosis and survival in macrophages; which was fully complemented by a single copy of the msfA1 gene. Using the chinchilla model of otitis media and invasive disease, the KO strain displayed a significant decrease in fitness compared to the WT in co-infections; and in single infections, the KO lost its ability to invade the brain. The singly complemented strain showed only a partial ability to compete with the WT suggesting gene dosage is important in vivo. The transcriptional profiles of the KO and WT in planktonic growth were compared using the NTHi supragenome array, which revealed highly significant changes in the expression of operons involved in virulence and anaerobiosis. These findings demonstrate that the msfA1-4 genes are virulence factors for phagocytosis, persistence, and trafficking to non-mucosal sites.

  4. Role of the nuclease of nontypeable Haemophilus influenzae in dispersal of organisms from biofilms.

    Science.gov (United States)

    Cho, Christine; Chande, Aroon; Gakhar, Lokesh; Bakaletz, Lauren O; Jurcisek, Joseph A; Ketterer, Margaret; Shao, Jian; Gotoh, Kenji; Foster, Eric; Hunt, Jason; O'Brien, Erin; Apicella, Michael A

    2015-03-01

    Nontypeable Haemophilus influenzae (NTHI) forms biofilms in the middle ear during human infection. The biofilm matrix of NTHI contains extracellular DNA. We show that NTHI possesses a potent nuclease, which is a homolog of the thermonuclease of Staphylococcus aureus. Using a biofilm dispersal assay, studies showed a biofilm dispersal pattern in the parent strain, no evidence of dispersal in the nuclease mutant, and a partial return of dispersion in the complemented mutant. Quantitative PCR of mRNA from biofilms from a 24-h continuous flow system demonstrated a significantly increased expression of the nuclease from planktonic organisms compared to those in the biofilm phase of growth (P < 0.042). Microscopic analysis of biofilms grown in vitro showed that in the nuclease mutant the nucleic acid matrix was increased compared to the wild-type and complemented strains. Organisms were typically found in large aggregates, unlike the wild-type and complement biofilms in which the organisms were evenly dispersed throughout the biofilm. At 48 h, the majority of the organisms in the mutant biofilm were dead. The nuclease mutant formed a biofilm in the chinchilla model of otitis media and demonstrated a propensity to also form similar large aggregates of organisms. These studies indicate that NTHI nuclease is involved in biofilm remodeling and organism dispersal.

  5. Antisera Against Certain Conserved Surface-Exposed Peptides of Nontypeable Haemophilus influenzae Are Protective.

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    Paul W Whitby

    Full Text Available Nontypeable Haemophilus influenzae (NTHi cause significant disease, including otitis media in children, exacerbations of chronic obstructive pulmonary disease, and invasive disease in susceptible populations. No vaccine is currently available to prevent NTHi disease. The interactions of NTHi and the human host are primarily mediated by lipooligosaccharide and a complex array of surface-exposed proteins (SEPs that act as receptors, sensors and secretion systems. We hypothesized that certain SEPs are present in all NTHi strains and that a subset of these may be antibody accessible and represent protective epitopes. Initially we used 15 genomic sequences available in the GenBank database along with an additional 11 genomic sequences generated by ourselves to identify the core set of putative SEPs present in all strains. Using bioinformatics, 56 core SEPs were identified. Molecular modeling generated putative structures of the SEPs from which potential surface exposed regions were defined. Synthetic peptides corresponding to ten of these highly conserved surface-exposed regions were used to raise antisera in rats. These antisera were used to assess passive protection in the infant rat model of invasive NTHi infection. Five of the antisera were protective, thus demonstrating their in vivo antibody accessibility. These five peptide regions represent potential targets for peptide vaccine candidates to protect against NTHi infection.

  6. Properties of mutants of haemophilus influenzae deficient in ATP-dependent deoxyribonuclease

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.

    1976-01-01

    Eight isogenic Haemophilus influenzae strains whose extracts lack ATP-dependent deoxyribonuclease activity (Add/sup -/ mutants) form three complementation and genetic linkage groups. Since there are known to be three subunits of the enzyme, these data suggest that each of the three genes specifies a different subunit. Gel electrophoresis of partially purified mutant extracts indicates that the smallest subunit is missing in one of the groups but is present in all the other mutants. The mutants are more sensitive to a variety of chemical agents than the wild type. The most sensitive mutants lack the ATPase activity associated with the enzyme. These strains exhibit aberrant incorporation of tritiated thymidine, which starts up more rapidly and shuts off sooner than in the wild type. An extracellular compound is responsible for most of this effect, in that wild type cells put into medium in which Add/sup -/ cells have been growing show a similar aberrant incorporation. The effect of these media can be mimicked by cyclic AMP and cyclic GMP, although millimolar concentrations are required. It is postulated that the Add/sup -/ mutants are more permeable to many substances than the wild type, partly because of the extracellular compound usually surrounding them, and the increased permeability might be responsible for the mutants' nonviability.

  7. The Expression of Soluble and Active Recombinant Haemophilus influenzae IgA1 Protease in E. coli

    Directory of Open Access Journals (Sweden)

    Shinong Long

    2010-01-01

    Full Text Available Immunoglobulin A1 (IgA1 proteases from Haemophilus influenzae are extracellular proteases that specifically cleave the hinge region of human IgA1, the predominant class of immunoglobulin present on mucosal membranes. The IgA1 proteases may have the potential to cleave IgA1 complexes in the kidney and be a therapeutic agent for IgA1 nephropathy (IgAN, a disease characterized by deposition of the IgA1 antibody in the glomerulus. We have screened for the expression of recombinant H. influenzae IgA1 protease by combining various expression plasmids, IgA1 protease constructs, and E. coli strains under multiple conditions. Using the method we have developed, approximately 20–40 mg/L of soluble and active H. influenzae IgA1 protease can be produced from E. coli strain C41(DE3, a significant increase in yield compared to the yield upon expression in H. influenzae or other related bacteria.

  8. Vaccine Candidates against Nontypeable Haemophilus influenzae: a Review

    Science.gov (United States)

    Behrouzi, Ava; Vaziri, Farzam; Rahimi-Jamnani, Fatemeh; Afrough, Parviz; Rahbar, Mohammad; Satarian, Fereshteh; Siadat, Seyed Davar

    2017-01-01

    Nonencapsulated, nontypeable Hemophilus influenzae (NTHi) remains an important cause of acute otitis and respiratory diseases in children and adults. NTHi bacteria are one of the major causes of respiratory tract infections, including acute otitis media, cystic fibrosis, and community-acquired pneumonia among children, especially in developing countries. The bacteria can also cause chronic diseases such as chronic bronchitis and chronic obstructive pulmonary disease in the lower respiratory tract of adults. Such bacteria express several outer membrane proteins, some of which have been studied as candidates for vaccine development. Due to the lack of effective vaccines as well as the spread and prevalence of NTHi worldwide, there is an urgent need to design and develop effective vaccine candidates against these strains. PMID:28088130

  9. Laboratory identification of Haemophilus influenzae: effects of basal media on the results of the satellitism test and evaluation of the RapID NH system.

    OpenAIRE

    1984-01-01

    The effects of four different basal media, tryptic soy agar, brain heart infusion agar, nutrient agar, and Mueller-Hinton agar, were investigated with respect to the identification of Haemophilus influenzae with a satellitism test in which X and V growth factors were supplied by factor-impregnated filter paper strips. A total of 187 recent clinical isolates of H. influenzae were examined. Of these, 179 strains (95.7%) were correctly identified with tryptic soy agar, 173 (92.5%) with brain hea...

  10. A plasmid carrying mucA and mucB genes from pKM101 in Haemophilus influenzae and Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Spikes, D.; Setlow, J.K. (Brookhaven National Lab., Upton, NY (USA))

    1989-10-01

    The plasmid pMucAMucB, constructed from the Haemophilus influenzae vector pDM2, and a similar plasmid, constructed from pBR322, increased the survival after UV irradiation of Escherichia coli AB1157 with the umu-36 mutation and also caused UV-induced mutation in the E. coli strain. In H. influenzae, pMucAMucB caused a small but reproducible increase in survival after UV irradiation in wild-type cells and in a rec-1 mutant, but there was no increase in spontaneous mutation in the wild type or in the rec-1 mutant and no UV-induced mutation.

  11. A molecular analysis of quinolone-resistant Haemophilus influenzae: validation of the mutations in Quinolone Resistance-Determining Regions.

    Science.gov (United States)

    Shoji, Hisashi; Shirakura, Tetsuro; Fukuchi, Kunihiko; Takuma, Takahiro; Hanaki, Hideaki; Tanaka, Kazuo; Niki, Yoshihito

    2014-04-01

    The mechanism of quinolone-resistance is considered to be amino acid mutations in the type II topoisomerase. We validated the genetic mechanisms of quinolone resistance in Haemophilus influenzae. We obtained 29 H. influenzae strains from a nationwide surveillance program in Japan (including 11 quinolone-resistant strains [moxifloxacin: MFLX or levofloxacin MIC ≥2 μg/ml]). We analyzed the sequences of the Quinolone Resistance-Determining Regions (QRDRs) in GyrA, GyrB, ParC and ParE. Furthermore, we induced resistance in susceptible strains by exposing them to quinolone, and investigated the relationship between mutations in the QRDRs and the MICs. Five amino acid substitutions in GyrA (at Ser84 and Asp88) and ParC (at Gly82, Ser84 and Glu88) were found to be closely related to the MICs. The strains with a MFLX MIC of 0.125-1 and 2-4 μg/ml had one and two mutations, respectively. The strains with a MFLX MIC of ≥8 μg/ml had three or more mutations. The strains with induced resistance with MFLX MICs of 0.5-1 and ≥2 μg/ml also had one and two mutations, respectively. We confirmed that these five mutations strongly contribute to quinolone resistance and found that the degree of resistance is related to the number of the mutations. In addition, the three strains of 18 susceptible strains (16.7%) also had a single mutation. These strains may therefore be in the initial stage of quinolone resistance. Currently, the frequency of quinolone-resistant H. influenzae is still low. However, as has occurred with β-lactams, an increase in quinolone use may lead to more quinolone-resistant strains.

  12. Genetic identification of cryptic genospecies of Haemophilus causing urogenital and neonatal infections by PCR using specific primers targeting genes coding for 16S rRNA.

    Science.gov (United States)

    Quentin, R; Ruimy, R; Rosenau, A; Musser, J M; Christen, R

    1996-06-01

    Previous genetic analysis of Haemophilus influenzae strains isolated from genital and neonatal infections identified a group of biotype IV that constitutes a cryptic genospecies only distantly related to H. influenzae and H. Haemolyticus. Small-subunit rRNA genes of two representative strains of this genital Haemophilus genospecies (strains 16N and 2406) were sequenced. The analysis indicated that these strains form a monophyletic unit with H. haemolyticus and H. influenzae biogroups Influenzae and Aegyptius and are more closely related to H. haemolyticus than to H. influenzae biogroups Influenzae and Aegyptius. 16S rRNA gene sequences were used to formulate primers for PCR-based identification of cryptic genital Haemophilus organisms. A 242-bp fragment was amplified from strains belonging to the genital Haemophilus genospecies but not from strains of 12 other Haemophilus species, including strains of H. influenzae biotype IV sensu stricto.

  13. Tracing phylogenomic events leading to diversity of Haemophilus influenzae and the emergence of Brazilian Purpuric Fever (BPF)-associated clones.

    Science.gov (United States)

    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.

  14. Haemophilus influenzae resides in tonsils and uses immunoglobulin D binding as an evasion strategy.

    Science.gov (United States)

    Singh, Kalpana; Nordström, Therése; Mörgelin, Matthias; Brant, Marta; Cardell, Lars-Olaf; Riesbeck, Kristian

    2014-05-01

    Haemophilus influenzae (Hi) causes respiratory tract infections and is also considered to be a commensal, particularly in preschool children. Tonsils from patients (n = 617) undergoing tonsillectomy due to chronic infection or hypertrophy were examined. We found that 51% of tonsils were positive for Hi, and in 95% of cases analyzed in detail (n = 39) Hi resided intracellularly in the core tonsillar tissue. Patients harbored several intracellular unique strains and the majority were nontypeable Hi (NTHi). Interestingly, the isolated NTHi bound soluble immunoglobulin (Ig) D at the constant heavy chain domain 1 as revealed by recombinant IgD/IgG chimeras. NTHi also interacted with B lymphocytes via the IgD B-cell receptor, resulting in internalization of bacteria, T-cell-independent activation via Toll-like receptor 9, and differentiation into non-NTHi-specific IgM-producing cells. Taken together, IgD-binding NTHi leads to an unspecific immune response and may support the bacteria to circumvent the host defense.

  15. Loss of plasmids containing cloned inserts coding for novobiocin resistance or novobiocin sensitivity in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.; Spikes, D.; Ledbetter, M.

    1984-06-01

    Plasmids pNov1 and pNov1s, coding for resistance and sensitivity to novobiocin, respectively, were readily lost from wild-type Haemophilus influenzae but retained in a strain lacking an inducible defective prophage. The plasmid loss could be partly or wholly eliminated by a low-copy-number mutation in the plasmid or by the presence of certain antibiotic resistance markers in the host chromosome. Release of both phage HP1c1, measured by plaque assay, and defective phage, measured by electron microscopy, was increased when the plasmids were present. The frequency of recombination between pNov1 and the chromosome, causing the plasmid to be converted to pNov1s, could under some circumstances be decreased from the normal 60 to 70% to below 10% by the presence of a kanamycin resistance marker in the chromosome. This suggested that a gene product coded for by the plasmid, the expression of which was affected by the kanamycin resistance marker, was responsible for the high recombination frequency. Evidence was obtained from in vitro experiments that the gene product was a gyrase.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

    2015-01-01

    Non-typeable Haemophilus influenzae contains an N6-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. PMID:26215614

  18. Molecular epidemiology of nontypeable Haemophilus influenzae causing community-acquired pneumonia in adults.

    Directory of Open Access Journals (Sweden)

    Carmen Puig

    Full Text Available Nontypeable Haemophilus influenzae (NTHi is an opportunistic pathogen which causes a variety of respiratory infections. The objectives of the study were to determine its antimicrobial susceptibility, to characterize the β-lactam resistance, and to establish a genetic characterization of NTHi isolates. Ninety-five NTHi isolates were analyzed by pulsed field gel electrophoresis (PFGE and multi locus sequence typing (MLST. Antimicrobial susceptibility was determined by microdilution, and the ftsI gene (encoding penicillin-binding protein 3, PBP3 was PCR amplified and sequenced. Thirty (31.6% isolates were non-susceptible to ampicillin (MIC ≥ 2 mg/L, with 10 of them producing β-lactamase type TEM-1 as a resistance mechanism. After ftsI sequencing, 39 (41.1% isolates showed amino acid substitutions in PBP3, with Asn526 → Lys being the most common (69.2%. Eighty-four patients were successfully treated with amoxicillin/clavulanic acid, ceftriaxone and levofloxacin. Eight patients died due either to aspiration or complication of their comorbidities. In conclusion, NTHi causing CAP in adults shows high genetic diversity and is associated with a high rate of reduced susceptibility to ampicillin due to alterations in PBP3. The analysis of treatment and outcomes demonstrated that NTHi strains with mutations in the ftsI gene could be successfully treated with ceftriaxone or fluoroquinolones.

  19. Acid-soluble breakdown of homologous deoxyribonucleic acid adsorbed by Haemophilus influenzae: its biological significance

    Energy Technology Data Exchange (ETDEWEB)

    Stuy, J.H.

    1974-11-01

    Competent bacteria of Haemophilus influenzae strain Rd were exposed to various kinds of radioactive deoxyribonucleic acid (DNA) for short periods of time and at relatively low temperature. The fate of phage HP1 DNA was studied most extensively. Adsorbed DNA was partially acid solubilized by lysogens and by nonlysogens with very similar kinetics. The biological activity of the DNA decreased extensively in both lysogenic and nonlysogenic recipients. 2,4-Dinitrophenol had no effect on the acid solubilization but largely abolished the biological inactivation. Inactivation kinetics for three different markers and for the triple combination were roughly the same. The presence of 2,4-dinitrophenol in the medium, or the HP1 prophage in the chromosome, did not alter this observation. This suggests that acid solubilization involves the destruction of whole DNA molecules. In view of the absence of DNA homology between phage and host, it is concluded that acid-soluble breakdown of adsorbed transforming DNA is not an integral part of the donor DNA integration process. Behavior of mutant bacteria indicates that neither exonuclease III nor exonuclease V is involved.

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

    Science.gov (United States)

    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.

  1. A discrete role for FNR in the transcriptional response to moderate changes in oxygen by Haemophilus influenzae Rd KW20.

    Science.gov (United States)

    Jiang, Donald; Tikhomirova, Alexandra; Bent, Stephen J; Kidd, Stephen P

    2016-01-01

    The survival by pathogenic bacteria within the specific conditions of an anatomical niche is critical for their persistence. These conditions include the combination of toxic chemicals, such as reactive oxygen (ROS) and reactive nitrogen species (RNS), with factors relevant to cell growth, such as oxygen. Haemophilus influenzae senses oxygen levels largely through the redox state of the intracellular fumarate-nitrate global regulator (FNR). H. influenzae certainly encounters oxygen levels that fluctuate, but in reality, these would rarely reach a state that results in FNR being fully reduced or oxidized. We were therefore interested in the response of H. influenzae to ROS and RNS at moderately high or low oxygen levels and the corresponding role of FNR. At these levels of oxygen, even though the growth rate of an H. influenzae fnr mutant was similar to wild type, its ROS and RNS tolerance was significantly different. Additionally, the subtle changes in oxygen did alter the whole cell transcriptional profile and this was different between the wild type and fnr mutant strains. It was the changed whole cell profile that impacted on ROS/RNS defence, but surprisingly, the FNR-regulated, anaerobic nitrite reductase (NrfA) continued to be expressed and had a role in this phenotype.

  2. Prevalence of Haemophilus influenzae pharyngeal carriers in the school population of Catalonia. Working Group on invasive disease caused by Haemophilus influenzae.

    Science.gov (United States)

    Bou, R; Domínguez, A; Fontanals, D; Sanfeliu, I; Pons, I; Renau, J; Pineda, V; Lobera, E; Latorre, C; Majó, M; Salleras, L

    2000-06-01

    The objective of this study was to determine the prevalence of healthy Haemophilus influenzae (Hi) pharyngeal carriers in a representative sample of the Catalonian school population, as well as the factors associated. A two-stage cluster sampling was carried out. Parents were given a questionnaire to collect information on sociodemographic and epidemiological variables. A pharyngeal swab was performed on children when informed consent was given by parents, and was cultured on chocolate agar with 260 microg/ml bacitracin. Of the 1212 children studied, 316 (26%) H. influenzae carriers were detected: 5 (0.4%) serotype b, 1 (0.08%) serotype c, 6 (0.5%) serotype e, 5 (0.4%) serotype f, and 299 (24.7%) non-typable. Age, gender and geographical location were the only variables associated with H. influenzae carrier status. The prevalence of non-typable H. influenzae carriers was similar to that of studies carried out in other countries, while that of serotype b carriers was similar to the remainder of H. influenzae capsulates, and lower than that described in previous studies. These data are in accordance with the low incidence of the disease observed in our context, although the possibility that the vaccine coverage may have affected the results of this study cannot be dismissed.

  3. OpsX from Haemophilus influenzae Represents a Novel Type of Heptosyltransferase I in Lipopolysaccharide Biosynthesis

    OpenAIRE

    Gronow, Sabine; Brabetz, Werner; Lindner, Buko; Brade, Helmut

    2005-01-01

    The inner core region of the lipopolysaccharide (LPS) of Haemophilus influenzae is characterized by the presence of a phosphorylated 3-deoxy-α-d-manno-octulosonic acid (Kdo). In this study, we show that the heptosyltransferase I adding the first l-glycero-d-manno-heptose residue to this acceptor is encoded by the gene opsX, which differs in substrate specificity from the other heptosyltransferase I, known as WaaC.

  4. Invasive Haemophilus Influenzae Disease, Europe, 1996–2006

    Centers for Disease Control (CDC) Podcasts

    2010-03-15

    This podcast describes monitoring of Haemophilus influenzae disease in Europe from 1996 through 2006. CDC epidemiologist Stacey Martin discusses what researchers learned about the effect of vaccination on disease prevalence.  Created: 3/15/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID); National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 4/5/2010.

  5. Septic arthritis and hemarthroses caused by Haemophilus influenzae serotype A in children

    Directory of Open Access Journals (Sweden)

    Ravi S. Samraj

    2016-09-01

    Full Text Available Invasive disease caused by Haemophilus influenzae serotype A (Hia is rare in children. Clinical syndromes caused by Hia include meningitis, sepsis and respiratory tract infections. Septic arthritis is rare in children with invasive Hia infection and hemarthrosis has not been described in the published literature. We report a case of septic arthritis and hemarthrosis caused by Hia infection in a 2.5 year-old-boy and review invasive Hia infection in children.

  6. Septic Arthritis and Hemarthroses Caused by Haemophilus Influenzae Serotype A in Children

    Science.gov (United States)

    Samraj, Ravi S.; Fergie, Jaime

    2016-01-01

    Invasive disease caused by Haemophilus influenzae serotype A (Hia) is rare in children. Clinical syndromes caused by Hia include meningitis, sepsis and respiratory tract infections. Septic arthritis is rare in children with invasive Hia infection and hemarthrosis has not been described in the published literature. We report a case of septic arthritis and hemarthrosis caused by Hia infection in a 2.5 year-old-boy and review invasive Hia infection in children.

  7. VAKSIN HAEMOPHILUS INFLUENZAE type b (Hib UNTUK PENCEGAHAN MENINGITIS DAN PNEUMONIA

    Directory of Open Access Journals (Sweden)

    Muljati Prijanto

    2012-09-01

    Full Text Available Rendahnya insiden pada anak yang lebih tua umurnya dan orang dewasa disebabkan karena adanya antibodi bakterisidal terhadap capsul polisakarida Haemophilus influenzae tipe b dalam serumnya.Di negara maju maupun negara berkembang bakteri merupakan penyebab utama non epidemik meningitis pada kelompok umur tersebut. Beberapa bukti menunjukkan bahwa mortalitas meningitis pada kelompok bayi muda lebih tinggi di negara berkembang dari pada di negara industri. 

  8. Mutation induction in Haemophilus influenzae by ICR-191 II. Role of DNA replication and repair

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, R.F.; Perdue, S.W.

    1981-01-01

    Evidence is presented to show that presumptive frameshift mutations induced in Haemophilus influenzae by ICR-191 are fixed very repidly, essentially at the time of treatment. DNA synthesis during treatment is essential for fixation, but DNA synthesis after treatment has no effect. The conclusion is drawn that the mutagen acts at the replication fork, possibly to stabilize misannealings arising in association with the discontinuities in the newly synthesized DNA. (JMT)

  9. Haemophilus influenzae outer membrane vesicle-induced blood-brain barrier permeability during experimental meningitis.

    OpenAIRE

    Wispelwey, B; Hansen, E J; Scheld, W M

    1989-01-01

    Haemophilus influenzae type b (Hib) lipopolysaccharide (LPS) may be present in the cerebrospinal fluid largely as part of outer membrane vesicles (OMV), which could possibly alter its activity. Similar to inoculation of purified Hib LPS, intracisternal inoculation of Hib OMV into adult rats resulted in dose- and time-dependent increases in blood-brain barrier permeability. Polymyxin B, but not an oligosaccharide-specific monoclonal antibody, significantly inhibited the activity of Hib OMV. No...

  10. Haemophilus influenzae as a cause of Brodie's abscess in an infant.

    Science.gov (United States)

    Kurlandsky, L E; Quinn, P H; Sills, E M

    1979-01-01

    Brodie's abscess is a form of subacute osteomyelitis which is defined by a particular constellation of clinical, radiological and pathological features. Its occurrence in infants is extremely rare. This case documents just such an occurrence. To our knowledge, the pathogen Haemophilus influenzae has not been previously recognized as a cause of Brodie's abscess in particular or subacute osteomyelitis in general. The clinical presentation and diagnostic pitfalls which may be encountered in this age group are discussed.

  11. The effects of Haemophilus influenzae vaccination on an aphylactic mediator release and isoprenaline-induced inhibition of mediator release

    NARCIS (Netherlands)

    Schreurs, A.J.M.; Terpstra, G.K.; Raaijmakers, J.A.M.; Nijkamp, F.P.

    1980-01-01

    The influence of Haemophilus influenzae on anaphylactic mediator from ovalbumin-sensitized isolated guinea pig lungs was investigated. Lungs from H. influenzae-vaccinated animals released protaglandins and thromboxanes following a smaller dose of ovalbumin than was effective in non-vaccinated animal

  12. Non-typeable Haemophilus influenzae purulent pericarditis in a child with cystic fibrosis.

    Science.gov (United States)

    Downes, Kevin J; Abulebda, Kamal; Siracusa, Christopher; Moore, Ryan; Staat, Mary A; Poynter, Sue E

    2016-07-01

    Early airway colonization and infection with Haemophilus influenzae in children with cystic fibrosis (CF) is common. Although the pathogenicity of non-typeable H. influenzae (NTHi) in patients with CF is controversial, this organism can cause both upper and lower respiratory tract infections. Extra-pulmonary disease, however, is rare. Purulent pericarditis is a suppurative complication of bacterial infection of the pericardial space that can arise as a result of direct extension from an adjacent infection. We describe a case of purulent pericarditis due to NTHi in a young child with CF that developed as a complication of inadequately treated bronchopneumonia.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, R.D.; Adams, M.D.; White, O. [Institute for Genomic Research, Gaithersburg, MD (United States)] [and others

    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.

  15. A glutathione-based system for defense against carbonyl stress in Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Kidd Stephen P

    2012-07-01

    Full Text Available Abstract Background adhC from Haemophilus influenzae encodes a glutathione-dependent alcohol dehydrogenase that has previously been shown to be required for protection against killing by S-nitrosoglutathione (GSNO. This group of enzymes is known in other systems to be able to utilize substrates that form adducts with glutathione, such as aldehydes. Results Here, we show that expression of adhC is maximally induced under conditions of high oxygen tension as well as specifically with glucose as a carbon source. adhC could also be induced in response to formaldehyde but not GSNO. An adhC mutant was more susceptible than wild-type Haemophilus influenzae Rd KW20 to killing by various short chain aliphatic aldehydes, all of which can be generated endogenously during cell metabolism but are also produced by the host as part of the innate immune response. Conclusions These results indicate that AdhC plays a role in defense against endogenously generated reactive carbonyl electrophiles in Haemophilus influenzae and may also play a role in defense against the host innate immune system.

  16. Cell vacuolation induced by Haemophilus influenzae supernatants in HEp-2 cells

    Directory of Open Access Journals (Sweden)

    Maria del Rosario Espinoza-Mellado

    2013-12-01

    Full Text Available Haemophilus influenzae belongs to respiratory tract microbiota. We observed vacuoles formation in previous studies with H. influenzae culture supernatants, so in this work we characterised that cytotoxic effect. We observed an abundant production of acidic cytoplasmic vacuoles due to the presence of a “vacuolating factor” in H. influenzae supernatants which was characterised as thermolabile. Greatest vacuolating activity was observed when utilizing the fraction > 50 kDa. The presence of a large number of vacuoles in HEp-2 cells was verified by transmission electron microscopy and some vacuoles were identified with a double membrane and/or being surrounded by ribosomes. These results suggest similar behaviour to that of vacuolating effects described by autotransporter proteins an undescribed cytotoxic effect induced by H. influenzae .

  17. Clinical characteristics of Haemophilus influenzae meningitis in Denmark in the post-vaccination era

    DEFF Research Database (Denmark)

    Pedersen, T.I.; Howitz, Michael Frantz; Andersen, Christian Østergaard

    2010-01-01

    P>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 24 years old [median 62 years (range 25...... 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...

  18. Antibodies to lipooligosaccharide of a Brazilian purpuric fever isolate of Haemophilus influenzae biogroup aegyptius lack bactericidal and protective activity.

    Science.gov (United States)

    Peters, V B; Rubin, L G

    1992-08-01

    The immunological basis for protection against Brazilian purpuric fever (BPF), a fulminant infection of young children associated with bacteremia with Haemophilus influenzae biogroup aegyptius, is unknown. Candidate antigens to which protective antibodies may be directed include cell surface proteins and lipooligosaccharide (LOS). We studied the activity of antisera to LOS purified from a BPF H. influenzae biogroup aegyptius isolate. Anti-LOS antisera contained anti-LOS antibody by enzyme immunoassay and immunoblot and no detectable anti-outer membrane protein antibodies by immunoblot. Anti-LOS antisera had minimal bactericidal activity and were not protective against the homologous strain in an infant rat model of bacteremia. Antiserum to whole bacterial cells had a titer of anti-LOS antibody similar to that of anti-LOS antisera and was bactericidal and protective. Removal of anti-LOS antibodies from anti-whole cell antiserum by affinity chromatography did not result in a loss of bactericidal activity. Serum from a normal adult contained anti-LOS antibodies and had bactericidal activity. However, anti-LOS antibodies purified from this serum did not have detectable bactericidal activity. These studies suggest that anti-LOS antibodies produced in rats are not bactericidal and do not contribute to protection against experimental bacteremia with BPF strains of H. influenzae biogroup aegyptius.

  19. Development of a diagnostic real-time polymerase chain reaction assay for the detection of invasive Haemophilus influenzae in clinical samples.

    LENUS (Irish Health Repository)

    Meyler, Kenneth L

    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.

  20. Isolation of Haemophilus influenzae and Haemophilus parainfluenzae in urethral exudates from men with acute urethritis: a descriptive study of 52 cases.

    Science.gov (United States)

    Deza, Gustavo; Martin-Ezquerra, Gemma; Gómez, Julià; Villar-García, Judit; Supervia, August; Pujol, Ramon M

    2016-02-01

    To describe the clinical characteristics and therapeutic outcomes from male patients diagnosed of Haemophilus spp urethritis. A chart review of patients who presented to our hospital from January 2013 to December 2014 with symptoms of acute urethritis in which Haemophilus spp was isolated in their urethral samples was performed. Haemophilus spp was isolated in 52 out of 413 urethral samples (12.6%) received in our laboratory from patients with symptoms of acute urethritis during the study period. Seven cases corresponded to Haemophilus influenzae and 45 cases to Haemophilus parainfluenzae. The most common clinical presentation was mucopurulent urethral discharge (71%). Eight per cent were HIV-infected patients, and 60% were men who have sex with men. Haemophilus spp was isolated as a single pathogen in 6.8% (28 of 413) of cases. Seventeen per cent of Haemophilus spp were β-lactamase producers. All patients reported having practiced unprotected insertive oral sex the month before consultation, and five of them denied having had another sexual contact apart from this exposure. In all cases in which follow-up was available, empirical treatment achieved a complete clinical resolution. Haemophilus spp was considered a pathogen in at least 6.8% of the patients from the evaluated area. It affected men regardless their sexual orientation or HIV status. Unprotected oral sex could play a role in its transmission. The limitations of the study (small sample size and lack of a representative control group) do not allow to prove the true pathogenic role of Haemophilus spp in acute urethritis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  1. Genomic analysis of the F3031 Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius by PCR-based subtractive hybridization.

    Science.gov (United States)

    Smoot, Laura M; Franke, Deanna D; McGillivary, Glen; Actis, Luis A

    2002-05-01

    PCR-based subtractive genome hybridization produced clones harboring inserts present in Brazilian purpuric fever (BPF) prototype strain F3031 but absent in noninvasive Haemophilus influenzae biogroup aegyptius isolate F1947. Some of these inserts have no matches in the GenBank database, while others are similar to genes encoding either known or hypothetical proteins. One insert represents a 2.3-kb locus with similarity to a Thermotoga maritima hypothetical protein, while another is part of a 7.6-kb locus that contains predicted genes encoding hypothetical, phage-related, and carotovoricin Er-like proteins. The presence of DNA related to these loci is variable among BPF isolates and nontypeable H. influenzae strains, while neither of them was detected in strains of types a to f. The data indicate that BPF-causing strain F3031 harbors unique chromosomal regions, most of which appear to be acquired from unrelated microbial sources.

  2. Antimicrobial resistance patterns of Haemophilus influenzae isolated from patients with meningitis in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Casagrande S.T.

    2000-01-01

    Full Text Available From 1989 to 1995, a total of 391 Haemophilus influenzae isolates were recovered from the cerebrospinal fluid (CSF of hospitalized patients in São Paulo, Brazil. The majority of strains were isolated from infants aged less than 5 years. Strains belonging to biotype I (64.7%, biotype II (34.5% and biotype IV (0.76% were detected. Ninety-nine percent of these strains were serotype b. Minimal inhibitory concentration (MIC was determined for ampicillin, chloramphenicol and ceftriaxone. The ß-lactamase assay was performed for all strains. The rate of ß-lactamase producer strains ranged from 10 to 21.4% during a period of 7 years, with an overall rate of 13.8%. Of the 391 strains analyzed, none was ß-lactamase negative ampicillin resistant (BLNAR. A total of 9.7% of strains showed resistance to both ampicillin and chloramphenicol; however, 4% of them were resistant to ampicillin only and 2% to chloramphenicol. All strains were susceptible to ceftriaxone and the MIC90 was 0.007 µg/ml, suggesting that ceftriaxone could be an option for the treatment of bacterial meningitis in pediatric patients who have not been screened for drug sensitivity.

  3. A chalcone with potent inhibiting activity against biofilm formation by nontypeable Haemophilus influenzae.

    Science.gov (United States)

    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.

  4. Effect of epithelial cell type on in vitro invasion of non-typeable Haemophilus influenzae.

    Science.gov (United States)

    Singh, Neeraj Kumar; Kunde, Dale A; Tristram, Stephen G

    2016-10-01

    Non-typeable Haemophilus influenzae (NTHi) have been shown to have variable ability for in vitro invasion with a range of epithelial cells, and increased invasion of BEAS-2B cells has been associated with altered penicillin binding protein3 (PBP3), which is concerning as these strains are increasing worldwide. The aim of the study was to investigate the effect of respiratory cell type and the presence of altered PBP3 on the in vitro invasion of NTHi. A collection of 16 clinical NTHi isolates was established, 7 had normal PBP3, and 9 had altered PBP3 as defined by an N526K substitution. The isolates were tested for invasion of BEAS-2B, NHBE, A549 and NCI-H292 respiratory epithelial cells in vitro using a gentamicin survival assay, with invasion measured as the percentage of intracellular organisms relative to the initial inoculum. The overall median invasion for the 16 NTHi isolates for cell types BEAS-2B, NHBE, A549 and NCI-H292 cells were 3.17, 2.31, 0.11 and 1.52 respectively. The differences were statistically significant for BEAS-2B compared to A549 (P=0.015) and A549 compared to NCI-H292 (P=0.015), and there were also very marked differences in invasion for some individual isolates depending on the cell type used. There was a consistent bias for invasion of isolates with normal versus abnormal PBP3: and this was statistically significant for BEAS-2B (0.07 to 9.90, P=0.031) and A549 cells (0.02 to 1.68, P=0.037). These results show that NTHi invasion of respiratory epithelial cells in vitro is both strain dependant and influenced significantly by the cell line used, and that the association between altered PBP3 and increased invasion is conserved across multiple cell lines.

  5. Prokaryotic High-Level Expression System in Producing Adhesin Recombinant Protein E of Nontypeable Haemophilus influenzae

    Science.gov (United States)

    Tavakoli, Minoo; Bouzari, Saeed; Siadat, Seyed Davar; Najar Peerayeh, Shahin; Jafari, Anis

    2015-01-01

    Background: Adhesion protein E (PE) of Haemophilus influenzae is a 16 - 18 kDa protein with 160 amino acids which causes adhesion to epithelial cells and acts as a major factor in pathogenesis. Objectives: In this study, we performed cloning, expression and purification of PE as a candidate antigen for vaccine design upon further study. Materials and Methods: At first, the pe gene of NTHi ATCC 49766 strain (483 bp) was amplified by PCR. Then, to sequence the resulted amplicon, it was cloned into TA vector (pTZ57R/T). In the next step, the sequenced gene was sub-cloned in pBAD/gIII A vector and transformed into competent Escherichia coli TOP10. For overexpression, the recombinant bacteria were grown in broth medium containing arabinose and the recombinant protein was purified using metal affinity chromatography (Ni-nitrilotriacetic acid) (Ni-NTA agarose). Finally, the protein was detected using sodium dodecyl sulfate polyacrylamide gel electrophores (SDS-PAG) and confirmed by western blotting. Results: The cloned gene was confirmed by PCR, restriction digestion and sequencing. The sequenced gene was searched for homology in GenBank and 99% similarity was found to the already deposited genes in GenBank. Then we obtained PE using Ni-NTA agarose with up to 7 mg/mL concentration. Conclusions: The pe gene was successfully cloned and confirmed by sequencing. Finally, PE was obtained with high concentration. Due to high homology and similarity among the pe gene from NTHi ATCC 49766 and other NTHi strains in GenBank, we believe that the protein is a universal antigen to be used as a vaccine design candidate and further studies to evaluate its immunogenicity is underway. PMID:26034537

  6. VERIFICATION OF THE PRESENCE OF CAPSULE GENE SEQUENCES IN NASOPHARYNGEAL ISOLATES OF NONTYPEABLE HAEMOPHILUS INFLUENZAE FROM HEALTHY CHILDREN AT A BRAZILIAN DAY CARE CENTER Verificação da presença de seqüências do gene da cápsula em cepas não tipáveis de Haemophilus influenzae isoladas da nasofaringe de crianças saudáveis em uma creche brasileira

    Directory of Open Access Journals (Sweden)

    Maria Emilia Bonifácio da Silva

    2001-10-01

    Full Text Available Fifty-eight nasopharyngeal isolates of Haemophilus influenzae were collected from healthy children at a day care center, and nontypeable isolates were examined by Southern blot for the presence of capsule gene sequences. Seven isolates (12% demonstrated homology with capsule-specific sequences. One isolate was characterized as an H. influenzae type b capsule-deficient strain.Cinqüenta e oito cepas de Haemophilus influenzae foram isoladas da nasofaringe de crianças saudáveis que freqüentam uma creche, e através da técnica de Southern blot foi pesquisada nas cepas acapsuladas a presença de seqüências do gene capsular. Sete cepas (12% caracterizadas sorologicamente como acapsuladas mostraram homologia com seqüências específicas da cápsula. Uma cepa foi caracterizada com uma linhagem H. influenzae tipo b cápsula deficiente.

  7. Haemophilus influenzae type b pneumonia in Egyptian children ...

    African Journals Online (AJOL)

    Tharwat Deraz

    2012-02-28

    Feb 28, 2012 ... b Department of Microbiology, Ain Shams University, Cairo, Egypt. Received 10 January 2012; ..... ilus influenza type b in children and its evaluation during a vaccine trial. Pediatr Infect Dis J ... virus prevalence. Vaccine 2006 ...

  8. Identification and structural characterization of a sialylated lacto-N-neotetraose structure in the lipopolysaccharide of Haemophilus influenzae.

    Science.gov (United States)

    Cox, Andrew D; Hood, Derek W; Martin, Adele; Makepeace, Katherine M; Deadman, Mary E; Li, Jianjun; Brisson, Jean-Robert; Moxon, E Richard; Richards, James C

    2002-08-01

    A sialylated lacto-N-neotetraose (Sial-lNnT) structural unit was identified and structurally characterized in the lipopolysaccharide (LPS) from the genome-sequenced strain Rd [corrected] (RM118) of the human pathogen Haemophilus influenzae grown in the presence of sialic acid. A combination of molecular genetics, MS and NMR spectroscopy techniques showed that this structural unit extended from the proximal heptose residue of the inner core region of the LPS molecule. The structure of the Sial-lNnT unit was identical to that found in meningococcal LPS, but glycoforms containing truncations of the Sial-lNnT unit, comprising fewer residues than the complete oligosaccharide component, were not detected. The finding of sialylated glycoforms that were either fully extended or absent suggests a novel biosynthetic feature for adding the terminal tetrasaccharide unit of the Sial-lNnT to the glycose acceptor at the proximal inner core heptose.

  9. Antibacterial FabH Inhibitors with Mode of Action Validated in Haemophilus influenzae by in Vitro Resistance Mutation Mapping.

    Science.gov (United States)

    McKinney, David C; Eyermann, Charles J; Gu, Rong-Fang; Hu, Jun; Kazmirski, Steven L; Lahiri, Sushmita D; McKenzie, Andrew R; Shapiro, Adam B; Breault, Gloria

    2016-07-01

    Fatty acid biosynthesis is essential to bacterial growth in Gram-negative pathogens. Several small molecules identified through a combination of high-throughput and fragment screening were cocrystallized with FabH (β-ketoacyl-acyl carrier protein synthase III) from Escherichia coli and Streptococcus pneumoniae. Structure-based drug design was used to merge several scaffolds to provide a new class of inhibitors. After optimization for Gram-negative enzyme inhibitory potency, several compounds demonstrated antimicrobial activity against an efflux-negative strain of Haemophilus influenzae. Mutants resistant to these compounds had mutations in the FabH gene near the catalytic triad, validating FabH as a target for antimicrobial drug discovery.

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

    Science.gov (United States)

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

    2015-05-01

    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 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 biofilm producers and nonproducers in the adenoid core and the nasopharynx were detected.H. influenzae and H

  11. Nonencapsulated Streptococcus pneumoniae causes otitis media during single-species infection and during polymicrobial infection with nontypeable Haemophilus influenzae.

    Science.gov (United States)

    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.

  12. Haemophilus influenzae LicB contributes to lung damage in an aged mice co-infection model.

    Science.gov (United States)

    Bondy, Jessica; Osharovich, Sofya; Storm, Julie; Durning, Graham; McAuliffe, Timothy; Fan, Xin

    2016-01-01

    Phosphorylcholine (ChoP) decoration of lipopolysaccharides is an important virulence strategy adopted by Haemophilus influenzae to establish a niche on the mucosal surface and to promote adherence to the host cells. The incorporation of ChoP on the LPS surface involves the lic1 operon, which consists of the licA, licB, licC, and licD genes. Among which, licB is a choline transporter gene required for acquisition of choline from environmental sources. In this study, we investigated the pathogenesis of the licB gene in an aged mice infection model. Due to immediate clearance of H. influenzae upon infection in mice, we employed influenza A virus and H. influenzae co-infection model. Our data showed that in the co-infection model, the secondary bacterial infection with a very low H. influenzae concentration of 100 colony forming unit is lethal to the aged mice. Although we did not observe any differences in weight loss between parent and licB mutant strains during the course of infection, a significant reduction of lung tissue damage was observed in the licB mutant infected aged mice. These results suggest that the licB gene is a virulence factor during H. influenzae infection in the lung in aged mice, possibly due to the increased binding to the host cell receptor via ChoP expression on the bacterial surface. In addition, when aged mice and mature mice were compared in the challenge experiments, we did not observe any protective immunity in the co-infection model suggesting the detrimental effects of the secondary bacterial infection on the aged mice in contrast to obvious immune-protections observed in the mature mice. The results of our experiments also implied that the co-infection model with influenza A virus and H. influenzae may be employed as a model system to study H. influenzae pathogenesis in vivo in aged mice.

  13. Creation of an isogenic P1-deficient mutant of Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Segada, L M; Lesse, A J

    1997-12-19

    Haemophilus influenzae biogroup aegyptius, the causative agent of Brazilian purpuric fever (BPF), expresses a heat-modifiable 48 kDa outer membrane protein, P1, which is conserved in most Brazilian case-clone isolates. To study the role of P1 in pathogenesis of BPF we constructed via homologous recombination an isogenic P1-deficient mutant of H. influenzae biogroup aegyptius. The procedure involved a modification of Hererot's method for development of competence. Modifications included variations in the growth conditions, use of cAMP, specific characteristics of the donor DNA, and antibiotic selection. P1-deficient mutants were confirmed by SDS-PAGE, loss of reactivity with a specific monoclonal antibody on Western blot, restriction analysis and Southern blot. Our results establish the first successful transformation of homologous DNA into H. influenzae biogroup aegyptius.

  14. Febre purpúrica brasileira, virulência em modelo animal do Haemophilus Aegyptius (H. influenzae biogrupo aegyptius Brazilian purpuric fever, virulence in animal model of Haemophilus Aegyptius (H. influenzae biogroup aegyptius

    Directory of Open Access Journals (Sweden)

    M.C.C. Brandileone

    1993-06-01

    Full Text Available Febre Purpúrica Brasileira (FPB é causada por cepas invasoras de Haemophilus aegyptius (H. influenzae biogrupo aegyptius, Hae. Estas cepas invasoras foram diferenciadas de cepas de Hae associadas apenas a conjuntivites (cepas não invasoras através de marcadores moleculares específicos. Modelo de ratos recém nascidos depletados de complemento foi aplicado ao estudo de cepas de Hae, associadas e não associadas a FPB, com o objetivo de se caracterizar seus potenciais de virulência. Com dose infectante de 10(5 células, as cepas invasoras causaram bacteriemia em 80-100% dos ratos inoculados,.e a magnitude da bacteriemia variou de 10(2,5±0,49 a > 10(4,69 ufc/ml de sangue. Usando a mesma dose infectante as cepas controles não causaram bacteriemia frequente (0 a 50% e a magnitude variou de 0 a 10(3,69±0,53 ufc/ml de sangue. As doses infectantes capazes de causar bacteriemia em 50% dos ratos inoculados (DB50% para as cepas invasoras de Hae variaram de 10(7,3 bactérias. Imunização passiva com antissoros produzidos com cepas invasoras demonstrou que os ratos foram protegidos das bacteriemias causadas pelas cepas homólogas, mas não da infecção causada pela cepa heteróloga. Comparando a bacteriemia causada pelas cepas de Hae com a bacteriemia causada pelo H. influenzae b, cepa Eagan (Hib, foi demonstrado o maior potencial de invasibilidade de Hib. Este modelo animal demonstrou ser útil para esclarecer o maior potencial de virulência das cepas invasoras de Hae.Brazilian purpuric fever (BPF is caused by invasive strains of Haemophilus aegyptius (H.influenzae biogroup aegyptius, Hae. These strains were differentiated from Hae strains associated only with conjunctivitis (non-invasive Hae strains through specific molecular markers. Complement-depleted infant rat model was used to study the invasive and non-invasive Hae strains to compare their virulence potential. Inoculating 10(5 bacteria in the rats, the invasive strains caused 80 to 100

  15. Killing curve activity of ciprofloxacin is comparable to synergistic effect of beta-lactam-tobramycin combinations against Haemophilus species endocarditis strains

    DEFF Research Database (Denmark)

    Westh, H; Frimodt-Møller, N; Gutschik, E

    1992-01-01

    Nine Haemophilus species strains, all beta-lactamase negative, isolated from patients with endocarditis were tested in killing curve experiments. Antibiotics used were penicillin, amoxicillin, aztreonam alone and in combination with tobramycin, as well as ciprofloxacin alone. Synergism between beta......-lactams and tobramycin with reduction of colony counts to zero was seen after 24 h for H. influenzae, H. parainfluenzae and H. segnis strains. Ciprofloxacin was as effective as beta-lactam-tobramycin combinations. The H. aphrophilus strain was not killed as effectively as other strains by any of the antibiotics....

  16. Invasive Haemophilus influenzae disease in the vaccine era in Rio de Janeiro, Brazil

    Science.gov (United States)

    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

  17. [Brazilian purpuric fever, virulence in an animal model of Haemophilus aegyptius (H. influenzae biogroup aegyptius). Grupo de Estudo da Febre Purpúrica Brasileira].

    Science.gov (United States)

    Brandileone, M C; Zanella, R C; Tondella, M L; Gheesling, L; Vieira, V S; Carlone, G M

    1993-01-01

    Brazilian purpuric fever (BPF) is caused by invasive strains of Haemophilus aegyptius (H. influenzae biogroup aegyptius, Hae). These strains were differentiated from Hae strains associated only with conjunctivitis (non-invasive Hae strains) through specific molecular markers. Complement-depleted infant rat model was used to study the invasive and non-invasive Hae strains to compare their virulence potential. Inoculating 10(5) bacteria in the rats, the invasive strains caused 80 to 100% bacteremia and the intensity of bacteremia was 10(2.5 +/- 0.49) to > 10(4.69) cfu/ml of blood. Using the same infectious dose, the non-invasive strains did not cause frequent bacteremia (0 to 50%) and the intensity was 0 to 10(3.69 +/- 0.53) cfu/ml of blood. The infectious doses able to cause 50% of bacteremia in the rats (BD 50%) varied from 10(7.3) bacteria for non-invasive strains. Passive immunization using antisera to invasive strains protected rats against bacteremia caused by homologous strains, but not by heterologous strain. By comparing the bacteremia caused by Hae and bacteremia caused by H. influenzae b (Eagan strain, Hib), it was demonstrated that Hib had higher virulence potential. This animal model was useful to clarify the virulence potential of invasive Hae strains.

  18. Immunization with Protein D from Non-Typeable Haemophilus influenzae (NTHi) Induced Cytokine Responses and Bioactive Antibody Production

    Science.gov (United States)

    Davoudi Vijeh Motlagh, Atefeh; Siadat, Seyed Davar; Abedian Kenari, Saeid; Mahdavi, Mehdi; Behrouzi, Ava; Asgarian-Omran, Hossein

    2016-01-01

    Background Outer membrane protein D (PD) is a highly conserved and stable protein in the outer membrane of both encapsulated (typeable) and non-capsulated (non-typeable) strains of Haemophilus influenzae. As an immunogen, PD is a potential candidate vaccine against non-typeable H. influenzae (NTHi) strains. Objectives The aim of this study was to determine the cytokine pattern and the opsonic antibody response in a BALB/c mouse model versus PD from NTHi as a vaccine candidate. Methods Protein D was formulated with Freund’s and outer membrane vesicle (OMV) adjuvants and injected into experimental mice. Sera from all groups were collected. The bioactivity of the anti-PD antibody was determined by opsonophagocytic killing test. To evaluate the cytokine responses, the spleens were assembled, suspension of splenocytes was recalled with antigen, and culture supernatants were analyzed by ELISA for IL-4, IL-10, and IFN-γ cytokines. Results Anti-PD antibodies promoted phagocytosis of NTHi in both immunized mice groups (those administered PD + Freund’s and those administered PD + OMV adjuvants, 92.8% and 83.5%, respectively, compared to the control group). In addition, the concentrations of three cytokines were increased markedly in immunized mice. Conclusions We conclude that immunization with PD protects mice against NTHi. It is associated with improvements in both cellular and humoral immune responses and opsonic antibody activity. PMID:27942362

  19. Characterization of P1-deficient isogenic mutant of Haemophilus influenzae biogroup aegyptius associated with Brazilian purpuric fever.

    Science.gov (United States)

    Segada, L M; Carlone, G M; Gheesling, L L; Lesse, A J

    2000-03-01

    Haemophilus influenzae biogroup aegyptius (formerly H. aegyptius) is the etiologic agent of Brazilian purpuric fever (BPF). A surface-exposed epitope on the outer membrane protein P1 is present on most strains of H. influenzae biogroup aegyptius associated with BPF but is absent in almost all non-disease associated strains. The role of the outer membrane protein P1 in the pathogenesis of this disease was evaluated by utilizing an isogenic P1-deficient mutant. We compared the ability of the wild type and P1 isogenic mutant to grow under various conditions. The P1-deficient strain grew at a similar rate to the wild type in both complex and chemically defined medium. The P1-deficient mutant also had a similar growth rate to the wild type under anaerobic conditions. Anaerobic growth, however, resulted in up-regulation of the P1 protein in the wild type strain. Three assays were used to examine the pathophysiologic role of the P1 protein in BPF: 1) serum resistance; 2) sustained bacteremia in the infant rat model; and 3) the human microvascular endothelial cell (HMEC) cytotoxicity assay. Both the mutant and wild-type strains were resistant to killing in 95% normal human serum. The P1-deficient strain was also as virulent as the wild type in both the infant rat model of bacteremia and in the HMEC-1 tissue culture model. These results demonstrate that serum resistance, sustained bacteremia in the infant rat, and cytotoxicity of HMEC cells occur in the absence of P1. The P1 protein is not essential for the pathogenic potential identified by these assays. However, these results demonstrate that an anaerobic environment is a potent physiologic regulator of P1 protein expression. The impact of anaerobiosis on protein expression and pathogenesis will require further investigations.

  20. Haemophilus influenzae with Non-Beta-Lactamase-Mediated Beta-Lactam Resistance: Easy To Find but Hard To Categorize.

    Science.gov (United States)

    Skaare, Dagfinn; Lia, Astrid; Hannisdal, Anja; Tveten, Yngvar; Matuschek, Erika; Kahlmeter, Gunnar; Kristiansen, Bjørn-Erik

    2015-11-01

    Haemophilus influenzae is a major pathogen, and beta-lactams are first-line drugs. Resistance due to altered penicillin-binding protein 3 (rPBP3) is frequent, and susceptibility testing of such strains is challenging. A collection of 154 beta-lactamase-negative isolates with a large proportion of rPBP3 (67.5%) was used to evaluate and compare Etest (Haemophilus test medium [HTM]) and disk diffusion (EUCAST method) for categorization of susceptibility to aminopenicillins and cefuroxime, using MICs generated with broth (HTM) microdilution and clinical breakpoints from CLSI and EUCAST as the gold standards. In addition, the proficiency of nine disks in screening for the rPBP3 genotype (N526K positive) was evaluated. By Etest, both essential and categorical agreement were generally poor (<70%), with high very major errors (VME) (CLSI, 13.0%; EUCAST, 34.3%) and falsely susceptible rates (FSR) (CLSI, 87.0%; EUCAST, 88.3%) for ampicillin. Ampicillin (2 μg) with adjusted (+2 mm) zone breakpoints was superior to Etest for categorization of susceptibility to ampicillin (agreement, 74.0%; VME, 11.0%; FSR, 28.3%). Conversely, Etest was superior to 30 μg cefuroxime for categorization of susceptibility to cefuroxime (agreement, 57.1% versus 60.4%; VME, 2.6% versus 9.7%; FSR, 7.1% versus 26.8%). Benzylpenicillin (1 unit) (EUCAST screening disk) and cefuroxime (5 μg) identified rPBP3 isolates with highest accuracies (95.5% and 92.2%, respectively). In conclusion, disk screening reliably detects rPBP3 H. influenzae, but false ampicillin susceptibility is frequent with routine methods. We suggest adding a comment recommending high-dose aminopenicillin therapy or the use of other agents for severe infections with screening-positive isolates that are susceptible to aminopenicillins by gradient or disk diffusion.

  1. Haemophilus influenzae with Non-Beta-Lactamase-Mediated Beta-Lactam Resistance: Easy To Find but Hard To Categorize

    Science.gov (United States)

    Lia, Astrid; Hannisdal, Anja; Tveten, Yngvar; Matuschek, Erika; Kahlmeter, Gunnar; Kristiansen, Bjørn-Erik

    2015-01-01

    Haemophilus influenzae is a major pathogen, and beta-lactams are first-line drugs. Resistance due to altered penicillin-binding protein 3 (rPBP3) is frequent, and susceptibility testing of such strains is challenging. A collection of 154 beta-lactamase-negative isolates with a large proportion of rPBP3 (67.5%) was used to evaluate and compare Etest (Haemophilus test medium [HTM]) and disk diffusion (EUCAST method) for categorization of susceptibility to aminopenicillins and cefuroxime, using MICs generated with broth (HTM) microdilution and clinical breakpoints from CLSI and EUCAST as the gold standards. In addition, the proficiency of nine disks in screening for the rPBP3 genotype (N526K positive) was evaluated. By Etest, both essential and categorical agreement were generally poor (<70%), with high very major errors (VME) (CLSI, 13.0%; EUCAST, 34.3%) and falsely susceptible rates (FSR) (CLSI, 87.0%; EUCAST, 88.3%) for ampicillin. Ampicillin (2 μg) with adjusted (+2 mm) zone breakpoints was superior to Etest for categorization of susceptibility to ampicillin (agreement, 74.0%; VME, 11.0%; FSR, 28.3%). Conversely, Etest was superior to 30 μg cefuroxime for categorization of susceptibility to cefuroxime (agreement, 57.1% versus 60.4%; VME, 2.6% versus 9.7%; FSR, 7.1% versus 26.8%). Benzylpenicillin (1 unit) (EUCAST screening disk) and cefuroxime (5 μg) identified rPBP3 isolates with highest accuracies (95.5% and 92.2%, respectively). In conclusion, disk screening reliably detects rPBP3 H. influenzae, but false ampicillin susceptibility is frequent with routine methods. We suggest adding a comment recommending high-dose aminopenicillin therapy or the use of other agents for severe infections with screening-positive isolates that are susceptible to aminopenicillins by gradient or disk diffusion. PMID:26354813

  2. Phylogenetic relationship of non-typeable Haemophilus influenzae isolated in Malaysia.

    Science.gov (United States)

    Mohd-Zain, Zaini; Kamsani, Nurul H; Ahmad, Norazah; Clarke, Stuart C

    2015-12-01

    The epidemiology of non-typeable Haemophilus influenzae (NTHi) remains poorly understood. We therefore sought to determine the genetic relationship of 25 NTHi isolated from various states in Malaysia using multilocus sequence typing (MLST). The majority of isolates were obtained from sputum. There were 24 novel sequence types (STs). Eight isolates were single-locus variants, the remainder being singletons. Clustering was not based on clinical site of isolation or geographical origin. Despite the limited number of isolates examined in this study, we demonstrate that NTHi isolates in Malaysia are diverse and warrant further investigation.

  3. Impact of the Haemophilus influenzae type b vaccination program on HIB meningitis in Brazil.

    Science.gov (United States)

    Miranzi, Sybelle de Souza Castro; de Moraes, Suzana Alves; de Freitas, Isabel Cristina Martins

    2007-07-01

    This study aimed to evaluate the impact of vaccination against Haemophilus influenzae type b (HIB) in Brazil on the morbidity, mortality, and case fatality of HIB meningitis, using the Ministry of Health database and population data from the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística--IBGE). Impact was evaluated through a time series analysis (1983-2002), using regression forecasting (RF) by dividing the time series into two periods: (a) historical (1983-1998) and (b) validation (1999-2002). Impact of the vaccination was positive, although more significant for incidence and mortality than for case fatality rates.

  4. Haemophilus influenzae susceptibilidad a los antimicrobianos y comportamiento frente a la vacuna en Cuba

    OpenAIRE

    Llop Hernández, Alina Etelvina

    2006-01-01

    Se presenta el resultado del Monitoreo/Vigilancia de la Resistencia de las cepas circulantes de Haemophilus influenzae en Cuba, aisladas de pacientes con procesos invasivos de meningoencefalitis bacteriana. Fueron estudiadas 1155 cepas colectadas recibidas de todo el paí­s, durante un período ininterrumpido de 17 años, desde enero del 1989 a diciembre de 2005. El trabajo se desarrolló en el Laboratorio Nacional de Referencia de Microbiologí­a del Instituto de Medicina Tropical "Pedro Kourí" M...

  5. Antibody response to Haemophilus influenzae type b capsular polysaccharide conjugated to tetanus toxoid in preterm infants

    DEFF Research Database (Denmark)

    Kristensen, Kim; Gyhrs, A; Lausen, B

    1996-01-01

    OBJECTIVE: To evaluate the antibody response to a Haemophilus influenzae type b capsular polysaccharide (HibCP) tetanus toxoid (TT) conjugate vaccine (HibCP-TT) in preterm infants. SUBJECTS: Thirty-five healthy preterm infants with gestational ages (GA) from 27 to 36 weeks and birth weights from...... no significant differences among the groups. The response to the TT part of the vaccine showed the same pattern. CONCLUSION: Although the most immature infants may show an inadequate antibody response to the initial immunizations, many preterm infants can benefit from vaccination with HibCP-TT when starting...

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

    Science.gov (United States)

    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.

  7. DNA repair in Haemophilus influenzae: isolation and characterization of an ultraviolet sensitive mutator mutant

    Energy Technology Data Exchange (ETDEWEB)

    Walter, R.B.

    1985-01-01

    DNA repair in Haemophilus influenzae appears to be quite different from that seen in Escherichia coli in that H. influenzae shows neither SOS nor adaptation phenomena. Repair of DNA lesions in H. influenzae has been seen to occur via recombinational, excision, and mismatch repair pathways acting independently of one another. The author has isolated an ultraviolet (UV)-sensitive mutator mutant (mutB1) of H. influenzae Rd which shows deficiencies in both recombinational and mismatch repair pathways. This mutant is sensitive to a variety of DNA damaging agents as well as being hypermutable by alkylating agents and base analogues. MutB1 cells do not show post-UV DNA breakdown but do begin excision after UV irradiation. Genetic transformation with UV-irradiated DNA on mut B1 recipients shows that high (HE) and low (LE) efficiency markers are transformed at a ratio of 1.0 as in the mismatch repair deficient hex 1 mutant; however, kinetics of UV-inactivation experiments indicate that HE markers are sensitized and act as LE markers do on wild type recipients. Thus, the mutB gene product appears to play a role in both DNA repair and genetic transformation. A model is outlined which presents a role for a DNA helicase in both DNA repair and genetic transformation of H. influenzae.

  8. Destruction of human microvascular endothelial cell capillary-like microtubules by Brazilian purpuric fever-associated Haemophilus influenzae biogroup aegyptius.

    Science.gov (United States)

    Quinn, F D; Weyant, R S; Candal, F J; Ades, E W

    1994-01-01

    When grown in the presence of Matrigel, monolayers of an immortalized human microvascular cell line (HMEC-1) form capillary-like microtubule networks. Previous work, using HMEC-1 monolayers, demonstrated a significant difference in in vitro cytotoxicity between Brazilian purpuric fever (BPF)-associated Haemophilus influenzae biogroup aegyptius (HAE) strains and non-BPF-associated HAE strains. The present study demonstrates that BPF-related cytotoxic differences can also be observed in HMEC-1 microtubule networks. At a multiplicity of infection (MOI) of 2 x 10(-2) bacteria/tissue culture cell, BPF-associated strain F3031 disrupted the microtubule network, producing random clumps of rounded cells at 48 h of incubation. Infection with non-BPF-associated strain F1947 at the same MOI produced no observable microtubule disruption. The ability of HMEC-1 microtubule model to differentiate virulent and avirulent HAE in vitro will further aid in the study of BPF pathogenesis. In addition, the fact that the HMEC-1 cells can be induced to form microtubules make it an excellent model system for the general study of many of the agents of vascular purpura.

  9. Haemophilus influenzae P4 Interacts With Extracellular Matrix Proteins Promoting Adhesion and Serum Resistance.

    Science.gov (United States)

    Su, Yu-Ching; Mukherjee, Oindrilla; Singh, Birendra; Hallgren, Oskar; Westergren-Thorsson, Gunilla; Hood, Derek; Riesbeck, Kristian

    2016-01-15

    Interaction with the extracellular matrix (ECM) is one of the successful colonization strategies employed by nontypeable Haemophilus influenzae (NTHi). Here we identified Haemophilus lipoprotein e (P4) as a receptor for ECM proteins. Purified recombinant P4 displayed a high binding affinity for laminin (Kd = 9.26 nM) and fibronectin (Kd = 10.19 nM), but slightly less to vitronectin (Kd = 16.51 nM). A P4-deficient NTHi mutant showed a significantly decreased binding to these ECM components. Vitronectin acquisition conferred serum resistance to both P4-expressing NTHi and Escherichia coli transformants. P4-mediated bacterial adherence to pharynx, type II alveolar, and bronchial epithelial cells was mainly attributed to fibronectin. Importantly, a significantly reduced bacterial infection was observed in the middle ear of the Junbo mouse model when NTHi was devoid of P4. In conclusion, our data provide new insight into the role of P4 as an important factor for Haemophilus colonization and subsequent respiratory tract infection.

  10. What the pediatrician should know about non-typeable Haemophilus influenzae.

    Science.gov (United States)

    Gilsdorf, Janet R

    2015-06-01

    Non-typeable Haemophilus influenzae (NTHi) live exclusively in the pharynges of humans and are increasingly recognized as pathogens that cause both localized infections of the respiratory tract (middle ear spaces, sinuses, and bronchi) and systemic infections such as bacteraemia and pneumonia. Only one vaccine antigen of NTHi, Protein D, has been extensively studied in humans and its efficacy in preventing NTHi otitis media is modest. Recent genetic analyses reveal that NTHi are closely related to Haemophilus haemolyticus (Hh), previously thought to be a non-pathogenic commensal of the pharynx. This review discusses the differences between the pathogenic potential of encapsulated and non-typeable Hi. In addition, information on the lifestyles and bacterial characteristics of NTHi and Hh as they pertain to their pathogenic capacities and the value of the Haemophilus taxonomy to clinicians are presented. Further, the epidemiology and mechanisms of NTHi antibiotic resistance, which include production of β-lactamase and alterations of penicillin-binding protein 3, are reviewed, as are the challenges of vaccine antigen discovery in NTHi.

  11. Selection for phase variation of LOS biosynthetic genes frequently occurs in progression of non-typeable Haemophilus influenzae infection from the nasopharynx to the middle ear of human patients.

    Directory of Open Access Journals (Sweden)

    Kate L Fox

    Full Text Available Surface structures in Haemophilus influenzae are subject to rapid ON/OFF switching of expression, a process termed phase variation. We analyse tetranucleotide repeats controlling phase variation in lipo-oligosaccharide (LOS genes of H. influenzae in paired isolates from both the nasopharynx and middle ears of paediatric patients with chronic or recurrent otitis media. A change in expression of at least one of the seven phase variable LOS biosynthesis genes was seen in 12 of the 21 strain pairs. Several strains showed switching of expression in multiple LOS genes, consistent with a key role for phase variable LOS biosynthetic genes in human infection.

  12. Towards a sustainable, quality and affordable Haemophilus influenzae type b vaccine for every child in the world

    NARCIS (Netherlands)

    Hamidi, A.

    2016-01-01

    Haemophilus influenzae type b (Hib) conjugate vaccine is a safe and effective vaccine that can prevent meningitis and pneumonia caused by Hib disease. Hib vaccine is recommended for all children under 5 years. Despite the availability of safe and effective Hib vaccines since early 1987, Gambia was

  13. Towards a sustainable, quality and affordable Haemophilus influenzae type b vaccine for every child in the world

    NARCIS (Netherlands)

    Hamidi, A.

    2016-01-01

    Haemophilus influenzae type b (Hib) conjugate vaccine is a safe and effective vaccine that can prevent meningitis and pneumonia caused by Hib disease. Hib vaccine is recommended for all children under 5 years. Despite the availability of safe and effective Hib vaccines since early 1987, Gambia was t

  14. Outbreak of amoxicillin-resistant Haemophilus influenzae type b: variable number of tandem repeats as novel molecular markers

    NARCIS (Netherlands)

    A.F. van Belkum (Alex); W.J. Melchers; C. IJsseldijk; L. Nohlmans; J.F. Meis; H.A. Verbrugh (Henri)

    1997-01-01

    textabstractAn outbreak caused by amoxicillin-resistant Haemophilus influenzae type b was noted among patients suffering from chronic obstructive pulmonary disease. Since infections were clustered in time and place, an ongoing outbreak was suspected. The spread of the s

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

    Energy Technology Data Exchange (ETDEWEB)

    Malouin, F.; Parr, T.R. Jr.; Bryan, L.E. (Eli Lilly Company, Indianapolis, IN (USA))

    1990-02-01

    (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.

  16. Meningitis - H. influenzae

    Science.gov (United States)

    H. influenzae meningitis; H. flu meningitis; Haemophilus influenzae type b meningitis ... H. influenzae meningitis is caused by Haemophilus influenzae type b bacteria. This illness is not the same as the flu ( influenza ), ...

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

    Science.gov (United States)

    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.

  18. [Brain abscess caused by Haemophilus influenzae type E in a pediatric patient suffering from Apert syndrome].

    Science.gov (United States)

    Isasmendi, Adela M; Pinheiro, José L; Escudé, Natalia García; Efrón, Adriana M; Moscoloni, María A; Hernández, Claudia M

    2014-01-01

    We report a case of a brain abscess caused by Haemophilus influenzae type e in a 12 year-old patient suffering from Apert syndrome. Apert syndrome is characterized by the premature closure of cranial sutures. In 2010 the patient suffered head trauma in the frontal area with cranial fracture and a cerebrospinal fluid fistula. In February 2013 he was admitted to hospital with fever, vomiting and generalized tonic-clonic seizure with deteriorating mental status/progressive sensory impairment. The computerized axial tomographic scan showed a right frontal lesion, perilesional edema, mild ventricular dilatation and pansinusitis. A brain abscess was diagnosed and drained. The clinical sample was then cultured. A gram negative coccobacillus was isolated and identified as Haemophilus influenzae serotype e. Empirical treatment was started with meropenem (120 mg/kg/day) and vancomycin (60 mg/kg/day), which was later switched to ceftriaxone (100 mg/kg/day) and metronidazole (500 mg/8 h) after culture results arrived. The patient was discharged in good clinical condition.

  19. Structure of the N-terminal region of Haemophilus Influenzae HI0017: Implications for function

    Energy Technology Data Exchange (ETDEWEB)

    Yu Liping; Mack, Jamey; Hajduk, Phil; Fesik, Stephen W. [Abbott Laboratories, Pharmaceutical Discovery Division, D46Y, AP10/LL (United States)

    2001-06-15

    Haemophilus influenzae is a gram-negative pathogen that causes infections ranging from asymptomatic colonization of the human upper respiratory tract to serious invasive diseases such as meningitis. Although the genome of Haemophilus influenzae has been completely sequenced, the structure and function of many of these proteins are unknown. HI0017 is one of these uncharacterized proteins. Here we describe the three-dimensional solution structure of the N-terminal portion of HI0017 as determined by NMR spectroscopy. The structure consists of a five-stranded antiparallel {beta}-sheet and two short {alpha}-helices. It is similar to the C-terminal domain of Diphtheria toxin repressor (DtxR). The C-terminal portion of HI0017 has an amino acid sequence that closely resembles pyruvate formate-lyase - an enzyme that converts pyruvate and CoA into acetyl-CoA and formate by a radical mechanism. Based on structural and sequence comparisons, we propose that the C-terminus of HI0017 functions as an enzyme with a glycyl radical mechanism, while the N-terminus participates in protein/protein interactions involving an activase (iron-sulfur protein) and/or the substrate.

  20. Fulminant bilateral Haemophilus influenzae keratitis in a patient with hypovitaminosis A treated with contaminated autologous serum

    Directory of Open Access Journals (Sweden)

    Empar Sanz-Marco

    2011-01-01

    Full Text Available Empar Sanz-Marco1, Manuel Diaz-Llopis1–3, Maria J Lopez-Prats1, Salvador Garcia-Delpech1,4, Patricia Udaondo11Ophthalmology, La Fe University Hospital of Valencia, Valencia, Spain; 2Faculty of Medicine, University of Valencia, Valencia, Spain; 3Biomedical Research Center for Rare Diseases Network (CIBERER, Valencia, Spain; 4Faculty of Medicine, Catholic University of Valencia, Valencia, SpainAbstract: We report on a patient with hypovitaminosis A treated with autologous serum (AS who had bilateral infectious ulcers positive for Haemophilus influenzae. The patient suffered a perforation of his right eye and total healing of his left eye with a residual leukoma. In cases of severe malnutrition, serum levels of vitamins and bacteriostatic and growth factors are reduced, so AS would not only be ineffective but also increase the risk of secondary corneal infection. The prophylactic use of a topical antibiotic would be useful in treatment with AS, especially in patients who do not use and adequately store the eye drops, as in our patient.Keywords: Haemophilus influenzae, hypovitaminosis A, bilateral infectious ulcers

  1. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains.

    Directory of Open Access Journals (Sweden)

    Dharanesh Gangaiah

    Full Text Available 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?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.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.

  2. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains.

    Directory of Open Access Journals (Sweden)

    Dharanesh Gangaiah

    Full Text Available 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?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.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.

  3. Immunogenicity of Nontypeable Haemophilus influenzae Outer Membrane Vesicles and Protective Ability in the Chinchilla Model of Otitis Media.

    Science.gov (United States)

    Winter, Linda E; Barenkamp, Stephen J

    2017-10-01

    Outer membrane vesicles (OMVs) produced by Gram-negative bacteria are enriched in several outer membrane components, including major and minor outer membrane proteins and lipooligosaccharide. We assessed the functional activity of nontypeable Haemophilus influenzae (NTHi) OMV-specific antisera and the protective ability of NTHi OMVs as vaccine antigens in the chinchilla otitis media model. OMVs were purified from three HMW1/HMW2-expressing NTHi strains, two of which were also engineered to overexpress Hia proteins. OMV-specific antisera raised in guinea pigs were assessed for their ability to mediate killing of representative NTHi in an opsonophagocytic assay. The three OMV-specific antisera mediated killing of 18 of 65, 24 of 65, and 30 of 65 unrelated HMW1/HMW2-expressing NTHi strains. Overall, they mediated killing of 39 of 65 HMW1/HMW2-expressing strains. The two Hia-expressing OMV-specific antisera mediated killing of 17 of 25 and 14 of 25 unrelated Hia-expressing NTHi strains. Overall, they mediated killing of 20 of 25 Hia-expressing strains. OMVs from prototype NTHi strain 12 were used to immunize chinchillas and the course of middle ear infection was monitored following intrabullar challenge with the homologous strain. All control animals developed culture-positive otitis media, as did two of three HMW1/HMW2-immunized animals. All OMV-immunized animals, with or without supplemental HMW1/HMW2 immunization, were completely protected against otitis media. NTHi OMVs are the first immunogens examined in this model that provided complete protection with sterile immunity after NTHi strain 12 challenge. These data suggest that NTHi OMVs hold significant potential as components of protective NTHi vaccines, possibly in combination with HMW1/HMW2 proteins. Copyright © 2017 American Society for Microbiology.

  4. Expression of hBD-2 induced by 23-valent pneumococcal polysaccharide vaccine, Haemophilus influenzae type b vaccine and split influenza virus vaccine.

    Science.gov (United States)

    Shen, Zhenwei; Lei, Han

    2012-10-01

    Human β-defensin-2 (hBD-2) is an antimicrobial peptide with high activity and broad spectrum activity. hBD-2 expression may be highly elevated by microorganisms and inflammation. We reported that the majority of common vaccines used, including 23-valent pneumococcal polysaccharide vaccine, Haemophilus influenzae type b vaccine and split influenza virus vaccine, could induce the expression of hBD-2 in epithelial cells. Among them, the 23-valent pneumococcal polysaccharide vaccine was effective at a lower concentration (0.5 µg/ml), while Haemophilus influenzae type b vaccine and split influenza virus vaccine were effective at the concentration of 1 µg/ml. However, bacteriostatic experiments revealed that the split influenza virus vaccine was capable of inducing the highest antimicrobial activity. The medium of the 23-valent pneumococcal polysaccharide vaccine treatment group had a higher antimicrobial activity than the medium of the Haemophilus influenzae type b vaccine treatment group. The transcriptional regulator of hBD-2, that is, the NF-κB subunit, had a high level of activity, while the normal epithelial cells showed barely detectable activity, indicating that these vaccines have potential for clinical application.

  5. Why we need a vaccine for non-typeable Haemophilus influenzae.

    Science.gov (United States)

    Cerquetti, Marina; Giufrè, Maria

    2016-09-01

    Nontypeable Haemophilus influenzae (NTHi) is increasingly recognized as emerging pathogen. The routine immunization of infants with conjugated vaccines against H. influenzae type b (Hib) has greatly reduced the incidence of invasive Hib disease; however a marked change in the predominant invasive serotype from Hib to NTHi has occurred. Localized infections where the role of H. influenzae is important, such as otitis media in children and acute exacerbations in chronic obstructive pulmonary disease (COPD) in adults, are almost exclusively associated with NTHi isolates. The implementation of pneumococcal conjugate vaccines has resulted in changes in frequency of nasopharynx colonizing pathogens with an increase of NTHi, although this data is yet under debate. An effective vaccine against NTHi is not currently available. The major challenge in developing a successful vaccine is the intrinsic heterogeneity of NTHi. H. influenzae protein D is used as carrier protein in the licensed 10-valent pneumococcal conjugate vaccine (Synflorix, GlaxoSmithKline), but no robust evidences for protective efficacy against NTHi otitis have been until now obtained. Several other vaccine candidates are under investigations and we hope that significant advancements in vaccine development will be achieved in the next future. Genome-based vaccine strategy might provide an additional useful tool for discovering further vaccine antigens.

  6. Degradation of DNA in Haemophilus influenzae cells after x-ray irradiation. II. Comparison with theoretical models

    Energy Technology Data Exchange (ETDEWEB)

    Randolph, M.L.

    1976-01-01

    Models of the kinetics of degradation of DNA in bacterial cells following exposure to x-rays are developed and tested using data obtained with various strains of Haemophilus influenzae cells. Different mathematical models allow for different initial distributions of DNA lengths, depending on cell phase and assumed replication model, and for unilateral or bilateral degradation from initiation points, which are taken as single-strand breaks. In order to explain the observed magnitude and time course of degradation an interruption-of-degradation probability, which may be interpreted as the result of an x-ray inducible inhibitor, is introduced. Interruption of degradation is interpreted as an early and essential, but not necessarily sufficient, step for repair of DNA. Empirical best fits to the kinetic data were obtained by iterative calculation methods based on varying the rate parameters. Depending somewhat on the strain and cell phase, the data seem best described by assuming bilateral degradation, perhaps at different rates, whose total for log phase wild-type cells is roughly 5 x 10/sup 3/ nucleotides/min and an interruption rate of about 0.03/min. For stationary phase the total degradation rate is greater and the probability of degradation unchanged. Differences in the kinetics between strains are discussed briefly.

  7. Frequency of Spontaneous Resistance to Peptide Deformylase Inhibitor GSK1322322 in Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae.

    Science.gov (United States)

    Min, Sharon; Ingraham, Karen; Huang, Jianzhong; McCloskey, Lynn; Rilling, Sarah; Windau, Anne; Pizzollo, Jason; Butler, Deborah; Aubart, Kelly; Miller, Linda A; Zalacain, Magdalena; Holmes, David J; O'Dwyer, Karen

    2015-08-01

    The continuous emergence of multidrug-resistant pathogenic bacteria is compromising the successful treatment of serious microbial infections. GSK1322322, a novel peptide deformylase (PDF) inhibitor, shows good in vitro antibacterial activity and has demonstrated safety and efficacy in human proof-of-concept clinical studies. In vitro studies were performed to determine the frequency of resistance (FoR) to this antimicrobial agent in major pathogens that cause respiratory tract and skin infections. Resistance to GSK1322322 occurred at high frequency through loss-of-function mutations in the formyl-methionyl transferase (FMT) protein in Staphylococcus aureus (4/4 strains) and Streptococcus pyogenes (4/4 strains) and via missense mutations in Streptococcus pneumoniae (6/21 strains), but the mutations were associated with severe in vitro and/or in vivo fitness costs. The overall FoR to GSK1322322 was very low in Haemophilus influenzae, with only one PDF mutant being identified in one of four strains. No target-based mutants were identified from S. pyogenes, and only one or no PDF mutants were isolated in three of the four S. aureus strains studied. In S. pneumoniae, PDF mutants were isolated from only six of 21 strains tested; an additional 10 strains did not yield colonies on GSK1322322-containing plates. Most of the PDF mutants characterized from those three organisms (35/37 mutants) carried mutations in residues at or in close proximity to one of three highly conserved motifs that are part of the active site of the PDF protein, with 30 of the 35 mutations occurring at position V71 (using the S. pneumoniae numbering system). Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Antimicrobial resistance in Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and group A beta-haemolytic streptococci in 2002-2003. Results of the multinational GRASP Surveillance Program

    DEFF Research Database (Denmark)

    Beekmann, Susan E; Heilmann, Kris P; Richter, Sandra S

    2005-01-01

    A multinational surveillance study, GRASP, was conducted between November 2002 and April 2003 with the aim of assessing rates of antimicrobial resistance among 2656 isolates of Streptococcus pneumoniae, 2486 isolates of group A beta-haemolytic streptococci, 1358 isolates of Haemophilus influenzae...... and 1047 of Moraxella catarrhalis from 20 countries in Europe, eastern Asia and southern Africa. Conspicuous differences between various countries were noted in the S. pneumoniae resistance rates observed for penicillin (0-79.2%) and erythromycin (4-66%), along with other antimicrobials. The percentage...... of MDR strains was above 25% in 8 of the 20 countries studied. Group A streptococcal macrolide resistance rates ranged from 0% to 35% by country, while rates of beta-lactamase production ranged from 0% to 39% for H. influenzae and 80-100% for M. catarrhalis. Antibiotic resistance in S. pneumoniae remains...

  9. The Actinobacillus pleuropneumoniae HMW1C-like glycosyltransferase mediates N-linked glycosylation of the Haemophilus influenzae HMW1 adhesin

    National Research Council Canada - National Science Library

    Choi, Kyoung-Jae; Grass, Susan; Paek, Seonghee; St Geme, 3rd, Joseph W; Yeo, Hye-Jeong

    2010-01-01

    The Haemophilus influenzae HMW1 adhesin is an important virulence exoprotein that is secreted via the two-partner secretion pathway and is glycosylated at multiple asparagine residues in consensus N-linked sequons...

  10. The modA10 phasevarion of nontypeable Haemophilus influenzae R2866 regulates multiple virulence-associated traits.

    Science.gov (United States)

    VanWagoner, Timothy M; Atack, John M; Nelson, Kevin L; Smith, Hannah K; Fox, Kate L; Jennings, Michael P; Stull, Terrence L; Smith, Arnold L

    2016-03-01

    Non-typeable Haemophilus influenzae (NTHi) is a human restricted commensal and pathogen that elicits inflammation by adhering to and invading airway epithelia cells: transcytosis across these cells can result in systemic infection. NTHi strain R2866 was isolated from the blood of a normal 30-month old infant with meningitis, and is unusual for NTHi in that it is able to cause systemic infection. Strain R2866 is able to replicate in normal human serum due to expression of lgtC which mimics human blood group p(k). R2866 contains a phase-variable DNA methyltransferase, modA10 which switches ON and OFF randomly and reversibly due to polymerase slippage over a long tetrameric repeat tract located in its open reading frame. Random gain or loss of repeats during replication can results in expressed (ON), or not expressed (OFF) states, the latter due to a frameshift or transcriptional termination at a premature stop codon. We sought to determine if the unusual virulence of R2866 was modified by modA10 phase-variation. A modA10 knockout mutant was found to have increased adherence to, and invasion of, human ear and airway monolayers in culture, and increased invasion and transcytosis of polarized human bronchial epithelial cells. Intriguingly, the rate of bacteremia was lower in the infant rat model of infection than a wild-type R2866 strain, but the fatality rate was greater. Transcriptional analysis comparing the modA10 knockout to the R2866 wild-type parent strain showed increased expression of genes in the modA10 knockout whose products mediate cellular adherence. We conclude that loss of ModA10 function in strain R2866 enhances colonization and invasion by increasing expression of genes that allow for increased adherence, which can contribute to the increased virulence of this strain.

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

    Directory of Open Access Journals (Sweden)

    Michael J Binks

    Full Text Available 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.

  12. The ToxAvapA toxin-antitoxin locus contributes to the survival of nontypeable Haemophilus influenzae during infection.

    Science.gov (United States)

    Ren, Dabin; Kordis, Alexis A; Sonenshine, Daniel E; Daines, Dayle A

    2014-01-01

    Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that is a common cause of acute and recurrent mucosal infections. One uncharacterized NTHi toxin-antitoxin (TA) module, NTHI1912-1913, is a host inhibition of growth (higBA) homologue. We hypothesized that this locus, which we designated toxAvapA, contributed to NTHi survival during infection. We deleted toxAvapA and determined that growth of the mutant in defined media was not different from the parent strain. We tested the mutant for persistence during long-term in vitro co-culture with primary human respiratory tissues, which revealed that the ΔtoxAvapA mutant was attenuated for survival. We then performed challenge studies using the chinchilla model of otitis media and determined that mutant survival was also reduced in vivo. Following purification, the toxin exhibited ribonuclease activity on RNA in vitro, while the antitoxin did not. A microarray comparison of the transcriptome revealed that the tryptophan biosynthetic regulon was significantly repressed in the mutant compared to the parent strain. HPLC studies of conditioned medium confirmed that there was no significant difference in the concentration of tryptophan remaining in the supernatant, indicating that the uptake of tryptophan by the mutant was not affected. We conclude that the role of the NTHi toxAvapA TA module in persistence following stress is multifactorial and includes effects on essential metabolic pathways.

  13. The ToxAvapA toxin-antitoxin locus contributes to the survival of nontypeable Haemophilus influenzae during infection.

    Directory of Open Access Journals (Sweden)

    Dabin Ren

    Full Text Available Nontypeable Haemophilus influenzae (NTHi is an opportunistic pathogen that is a common cause of acute and recurrent mucosal infections. One uncharacterized NTHi toxin-antitoxin (TA module, NTHI1912-1913, is a host inhibition of growth (higBA homologue. We hypothesized that this locus, which we designated toxAvapA, contributed to NTHi survival during infection. We deleted toxAvapA and determined that growth of the mutant in defined media was not different from the parent strain. We tested the mutant for persistence during long-term in vitro co-culture with primary human respiratory tissues, which revealed that the ΔtoxAvapA mutant was attenuated for survival. We then performed challenge studies using the chinchilla model of otitis media and determined that mutant survival was also reduced in vivo. Following purification, the toxin exhibited ribonuclease activity on RNA in vitro, while the antitoxin did not. A microarray comparison of the transcriptome revealed that the tryptophan biosynthetic regulon was significantly repressed in the mutant compared to the parent strain. HPLC studies of conditioned medium confirmed that there was no significant difference in the concentration of tryptophan remaining in the supernatant, indicating that the uptake of tryptophan by the mutant was not affected. We conclude that the role of the NTHi toxAvapA TA module in persistence following stress is multifactorial and includes effects on essential metabolic pathways.

  14. Lethal effect of mitomycin C on Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Small, G.D.; Setlow, J.K.; Kooistra, J.; Shapanka, R.

    1976-02-01

    The sensitivity of ultraviolet-sensitive strains to inactivation by mitomycin C (MC) is at the most only a factor of two greater than that of the wild type. The presence of inducible prophage has very little effect on the sensitivity. Genes which control excision of ultraviolet-induced pyrimidine dimers also control repair of MC-induced cross-links, as measured by resistance of denatured deoxyribonucleic acid (DNA) from treated cells to S1 nuclease digestion. However, endonucleolytic breaks in MC-damaged DNA, as judged by decreased single-strand molecular weight upon incubation of treated cells, are independent of these genes and probably are caused by monoadducts. After long periods of incubation there is a return to the molecular weight of untreated DNA. DNA degradation after MC treatment of various strains is not correlated with sensitivity to inactivation. Stationary-phase cells of all strains are more than twice as sensitive to MC as exponentially growing cells, and the sensitivity difference agrees with the measured difference in the number of cross-links after MC treatment of cells in the two growth stages. Evidence has been obtained that these phenomena result from differences in uptake of MC, which can be influenced by cyclic adenosine monophosphate. Small deviations in MC sensitivity from that of the wild type observed in mutants lacking the adenosine 5'-triphosphate-dependent nuclease are postulated to result from differences in MC uptake. These mutants, although no more ultraviolet sensitive than the wild type, are more sensitive to streptomycin, which also must be taken up by the cell to be effective. (auth)

  15. Ceftobiprole medocaril (BAL5788) treatment of experimental Haemophilus influenzae, Enterobacter cloacae, and Klebsiella pneumoniae murine pneumonia.

    Science.gov (United States)

    Rouse, Mark S; Hein, Melanie M; Anguita-Alonso, Paloma; Steckelberg, James M; Patel, Robin

    2006-08-01

    Ceftobiprole (BAL9141) is an investigational cephalosporin active against methicillin- and vancomycin-resistant staphylococci administered as a water-soluble prodrug, ceftobiprole medocaril (BAL5788). Using an immunocompetent murine pneumonia model of Haemophilus influenzae, Enterobacter cloacae, or extended-spectrum beta-lactamase (ESBL) nonproducing or producing Klebsiella pneumoniae pneumonia, we compared results of treatment with ceftobiprole medocaril (71 mg/kg, sc, qid), ceftriaxone (50 mg/kg, im, bid), or cefepime (50 mg/kg, ip, q.i.d.). Results were expressed as median and 25th to 75th percentile log10 colony forming units per gram of lung tissue. Ceftobiprole, ceftriaxone, and cefepime were each more active than was no treatment and were equally active for treatment of experimental H. influenzae, E. cloacae, or ESBL-nonproducing K. pneumoniae pneumonia. For ESBL-producing K. pneumoniae, no differences were detected between no treatment and treatment with ceftobiprole, ceftriaxone, or cefepime. Ceftobiprole is active against H. influenzae, E. cloacae, and ESBL-nonproducing K. pneumoniae in an immunocompetent experimental murine pneumonia model.

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

    Science.gov (United States)

    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.

  17. Detection of Haemophilus influenzae type b antigens in body fluids, using specific antibody-coated staphylococci.

    Science.gov (United States)

    Suksanong, M; Dajani, A S

    1977-01-01

    Protein A-rich staphylococci coated with Haemophilus influenzae type b antiserum agglutinate specifically with homologous bacterial cells or with cell-free supernatant fluids of cultures of the organism. Antibody-coated staphylococci were used to detect soluble antigens in body fluids of patients infected with H. influenzae type b. Cerebrospinal fluid from 36 cases of meningitis caused by this orgainsm showed positive coagglutination tests in 86% of patients prior to initiation of therapy. Antigens could be detected in 46% of sterile cerebrospinal fluid specimens obtained from the same cases 1 to 10 days after therapy. Soluble antigens were also detectable in sera (58%) and urine specimens (67%) of patients with H. influenzae type b septicemia, when such specimens were tested within 10 days of onset of illness. No antigen could be detected in body fluids beyond 10 days. The coagglutination test was positive in 57% of all body fluids examined; contercurrent immunoelectrophoresis (CCIE) was positive in only 27%. All specimens positive by CCIE were also positive by coagglutination. No false-positive reactions were noted by either test in body fluids from controls. The coagglutination test is simple, specific, and more sensitive than the CCIE method and could be a valuable tool for detecting antigens in body fluids of patients with various infections.

  18. Haemophilus influenzae surface fibril (Hsf) is a unique twisted hairpin-like trimeric autotransporter.

    Science.gov (United States)

    Singh, Birendra; Jubair, Tamim Al; Mörgelin, Matthias; Sundin, Anders; Linse, Sara; Nilsson, Ulf J; Riesbeck, Kristian

    2015-01-01

    The Haemophilus surface fibril (Hsf) is an extraordinary large (2413 amino acids) trimeric autotransporter, present in all encapsulated Haemophilus influenzae. It contributes to virulence by directly functioning as an adhesin. Furthermore, Hsf recruits the host factor vitronectin thereby inhibiting the host innate immune response resulting in enhanced survival in serum. Here we observed by electron microscopy that Hsf appears as an 100 nm long fibril at the bacterial surface albeit the length is approximately 200 nm according to a bioinformatics based model. To unveil this discrepancy, we denaturated Hsf at the surface of Hib by using guanidine hydrochloride (GuHCl). Partial denaturation induced in the presence of GuHCl unfolded the Hsf molecules, and resulted in an increased length of fibres in comparison to the native trimeric form. Importantly, our findings were also verified by E. coli expressing Hsf at its surface. In addition, a set of Hsf-specific peptide antibodies also indicated that the N-terminal of Hsf is located near the C-terminal at the base of the fibril. Taken together, our results demonstrated that Hsf is not a straight molecule but is folded and doubled over. This is the first report that provides the unique structural features of the trimeric autotransporter Hsf.

  19. Recurrent Posttraumatic Meningitis due to Nontypable Haemophilus influenzae: Case Report and Review of the Literature

    DEFF Research Database (Denmark)

    Kunze, W; Müller, L; Kilian, Mogens

    2007-01-01

    . 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. Expression and Purification of Haemophilus influenzae Rhomboid Intramembrane Protease GlpG for Structural Studies.

    Science.gov (United States)

    Panwar, Pankaj; Lemieux, M Joanne

    2014-04-01

    Rhomboid proteases are membrane-embedded proteases that cleave peptide bonds of transmembrane proteins. They play a variety of roles in cell signaling events. The rhomboid protease GlpG from Haemophilus influenzae (hiGlpG) is a canonical form of rhomboid protease having six transmembrane segments. In this unit, detailed protocols are presented for optimization of hiGlpG expression using the araBAD promotor system in the pBAD vector. The parameters for optimization include concentration of inducing agent, induction temperature, and time. Optimization of these key factors led to the development of a protocol yielding 1.6 to 2.5 mg/liter protein purified after ion metal affinity chromatography (IMAC). Further purification can include size exclusion chromatography (SEC).

  1. Structural requirements of the major protective antibody to Haemophilus influenzae type b

    DEFF Research Database (Denmark)

    Hougs, L; Juul, L; Svejgaard, A

    1999-01-01

    expressed as antigen-binding fragments (Fabs) in Escherichia coli, define amino acids involved in antigen binding and idiotype expression, and propose a three-dimensional structure for the variable domains. We found that canonical Fabs, unlike a noncanonical Fab, bound effectively to HibCP in the absence......Protective antibodies to the important childhood pathogen Haemophilus influenzae type b (Hib) are directed against the capsular polysaccharide (HibCP). Most of the antibody is encoded by a well-defined set of ("canonical") immunoglobulin genes, including the Vkappa A2 gene, and expresses...... an idiotypic marker (HibId-1). In comparison to noncanonical antibodies, the canonical antibody is generally of higher avidity, shows higher levels of in vitro bactericidal activity, and is more protective in infant rats. Using site-directed mutagenesis, we here characterize canonical HibCP antibodies...

  2. Fixation and loss of hydrazine-induced premutational damage in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, R.F.; Hirsch, B.F.

    1976-01-01

    Premutational damage induced in Haemophilus influenzae by hydrazine appears to be fixed as final mutation only at replication as judged by the transformation assay. Fixation at replication is independent of the rec 1 gene, unlike the case with nitrosocarbaryl. Prior to replication premutational damage induced by hydrazine disappears by an unknown process that is not dependent on the presence of a pyrimidine dimer excision system nor on the rec 1 gene. Hydrazine does not produce detectable single-strand breaks or alkali-labile sites in the treated DNA nor gaps in DNA newly synthesized after treatment. In these respects it also differs from nitroso compounds. It is concluded that hydrazine acts to produce an altered base, possibly N(4)-aminocytosine, that produces mutations by mispairing at replication rather than by error-prone repair.

  3. Developing a vaccine to prevent otitis media caused by nontypeable Haemophilus influenzae.

    Science.gov (United States)

    Khan, M Nadeem; Ren, Dabin; Kaur, Ravinder; Basha, Saleem; Zagursky, Robert; Pichichero, Michael E

    2016-07-01

    Nontypeable Haemophilus influenzae (NTHi) is a predominant organism of the upper respiratory nasopharyngeal microbiota. Its disease spectrum includes otitis media, sinusitis, non-bacteremic pneumonia and invasive infections. Protein-based vaccines to prevent NTHi infections are needed to alleviate these infections in children and vulnerable populations such as the elderly and those with chronic obstructive pulmonary disease (COPD). One NTHi protein is included in a pneumococcal conjugate vaccine and has been shown to provide efficacy. Our lab has been interested in understanding the immunogenicity of NTHi vaccine candidates P6, protein D and OMP26 for preventing acute otitis media in young children. We expect that continued investigation and progress in the development of an efficacious protein based vaccine against NTHi infections is achievable in the near future.

  4. Novobiocin resistance marker in Haemophilus influenzae that is not expressed on a plasmid

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.; McCarthy, D.; Clayton, N.L.

    1982-09-01

    The plasmid pNov2, carrying a cloned chromosomal marker conferring resistance to at least 2.5 ..mu..g of novobiocin per ml, was constructed with a new Haemophilus influenzae cloning vehicle, pDM2. The novobiocin marker of pNov2 was not normally expressed, but in Rec/sup +/ cells approximately one in 10/sup 4/ cells in a culture of a transformant became novobiocin resistant, a frequency about four orders of magnitude higher than the spontaneous mutation frequency. Variants of such cells that had lost the plasmid were also novobiocin resistant. Since Rec/sup -/ cultures bearing pNov2 showed novobiocin resistance only at the normal mutation frequency, the authors concluded that the Rec/sup +/ novobiocin-resistant transformants arose because of a rare recombination between plasmid and chromosome. Evidence is presented that novobiocin sensitivity is dominant over this particular novobiocin resistance marker.

  5. Electron microscopy of single-stranded structures in the DNA of competent Haemophilus influenzae cells

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, D.; Kupfer, D.M.

    1987-02-01

    Chromosomal DNAs from exponential-phase and competent cells of Haemophilus influenzae were examined by electron microscopy to determine whether the chromosome undergoes structural changes during competence development. Single-stranded gaps and single-stranded tails formed in chromosomal DNA during competence development. The generation of gaps was dependent on the rec-2 function. Since the rec-2 mutant is defective in the translocation of donor DNA, it was inferred that the gaps were involved in the translocation step of transformation. The generation of single-stranded tails was independent of the rec-1 and rec-2 genes. Therefore, these structures were assumed to play no direct role in the interaction of donor and recipient DNAs during transformation. Gaps were preferentially associated with a readily denaturable, possible A + T-rich fraction of the genome. This finding raised the possibility that hot spots for transformation might be associated with A + T-rich DNA.

  6. Use of Dorset egg medium for maintenance and transport of Neisseria meningitidis and Haemophilus influenzae type b.

    Science.gov (United States)

    Wasas, A D; Huebner, R E; Klugman, K P

    1999-06-01

    Studies of bacterial meningitis are hampered by the inability to maintain the viability of etiological agents during transport to reference laboratories. The long-term survival rate of 20 isolates of Neisseria meningitidis and Haemophilus influenzae type b (Hib) on Dorset egg medium, supplemented Columbia agar base medium, chocolate agar, and Amies medium was compared with that on 70% GC agar (chocolate) transport medium. N. meningitidis isolates were also inoculated onto 5% horse blood agar, and Hib was inoculated onto Haemophilus test medium. All of the N. meningitidis isolates remained viable on Dorset egg medium for 21 days; viability on the other media was poor after only 7 days. Recovery rates of Hib isolates were similar on Dorset egg and Haemophilus test media (100% after 21 days) and significantly better than on the other media. Dorset egg medium is inexpensive and easy to make and may be invaluable for studies of bacterial meningitis in developing countries.

  7. 2010-2012年流感嗜血杆菌耐药性监测%2010-2012 surveillance of antimicrobial resistance in haemophilus influenzae

    Institute of Scientific and Technical Information of China (English)

    龙姗姗; 喻华

    2014-01-01

    Objective To investigate the distribution and antimicrobial resistance of haemophilus influenzae ,and to pro-vide reference for reasonable use of antibiotics .Methods Clinical isolates from patients in our hospital from January 2010 to December 2012 were identified by VITEK2-compact automatic identification system , bacterial susceptibility tests were per-formed on strains by ATB system , the results were determined according to the guidelines of CLSI in 2012,and β-lactamase was detected by nitrocefin disk diffusion method .WHONET5.6 software was applied for data analysis .Results A total of 201 strains of haemophilus influenzae were obtained from our hospital in recent three years .Among them,193 strains were from sputum specimen (96.0%),6 from bronchoalveolar lavage fluid specimen (2.9%),2 from blood specimen (1.1%).As for the distribution of haemophilus influenzae in clinical departments ,the top three were respiratory department (104 strains, 51. 7%),surgical department (31 strains,15.4%) and ICU (27 strains,13.4%).The results of bacterial susceptibility tests showed that haemophilus influenzae was sensitive to rifampicin , ampicillin,chloramphenicol and cotrimoxazole with a rate of 45.5%,73.4%,87.5%and 87.1%respectively,and that the sensitive rate of haemophilus influenzae to amoxicillin /clavu-lanic acid,cefotaxime,cefaclor,tetracycline, cefuroxime and ofloxacin was higher than 90%.Isolates from adults were more sensitive to ampicillin and rifampicin than those from children ,but for tetracycline , isolates from children were more sensitive than those from adults .52 strains were positive to β-lactamase with a rate of 25.9%, and the rate of β-lactamase positive strains from children was significantly higher than that from adults .Conclusion Haemophilus influenzae has a higher resistant rate to rifampicin.Amoxicillin /clavulanate,cefotaxime,cefaclor,cefuroxime and ofloxacin are still the effective antibiotics for the control of haemophilus influenzae

  8. Antimicrobial activity of innate immune molecules against Streptococcus pneumoniae, Moraxella catarrhalis and nontypeable Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Teufert Karen

    2004-05-01

    Full Text Available Abstract Background Despite its direct connection to the nasopharynx which harbors otitis media pathogens as part of its normal flora, the middle ear cavity is kept free of these bacteria by as yet unknown mechanisms. Respiratory mucosal epithelia, including those of the middle ear and eustachian tube, secrete antimicrobial effectors including lysozyme, lactoferrin and β defensins-1 and -2. To elucidate the role of these innate immune molecules in the normal defense and maintenance of sterility of respiratory mucosa such as that of the middle ear, we assessed their effect on the respiratory pathogens nontypeable Haemophilus influenzae (NTHi 12, Moraxella catarrhalis 035E, and Streptococcus pneumoniae 3, and 6B. Methods Two assay methods, the radial assay and the liquid broth assay, were employed for testing the antimicrobial activity of the molecules. This was done in order to minimize the possibility that the observed effects were artifacts of any single assay system employed. Also, transmission electron microscopy (TEM was employed to evaluate the effect of antimicrobial innate immune molecules on OM pathogens. For the statistical analysis of the data, Student's t-test was performed. Results Results of the radial diffusion assay showed that β defensin-2 was active against all four OM pathogens tested, while treatment with β defensin-1 appeared to only affect M. catarrhalis. The radial assay results also showed that lysozyme was quite effective against S. pneumoniae 3 and 6B and was partially bacteriostatic/bactericidal against M. catarrhalis. Lysozyme however, appeared not to affect the growth of NTHi. Thus, lysozyme seems to have a more pronounced impact on the growth of the Gram-positive S. pneumoniae as compared to that of Gram-negative pathogens. Lactoferrin on the other hand, enhanced the growth of the bacteria tested. The results of the radial assays were confirmed using liquid broth assays for antimicrobial activity, and showed that

  9. 北京和天津两地在校学生流感嗜血杆菌携带情况监测%The carriage of haemophilus influenzae in students from Beijing and Tianjin

    Institute of Scientific and Technical Information of China (English)

    张铁钢; 罗明; 龚成; 吕敏; 丁小静; 牛艳芬; 吴疆

    2012-01-01

    Objective:To monitor the carriage of Haemophilus influenza in students from Beijing and Tianjin in 2009 and 2010. Methods: In Beijing and Tianjin, the clinical specimens were collected from the school students with acute upper respiratory tract infection. The nucleic acids detection and serotyping of haemophilus influenzae and serotyping were performed with molecular technology. Results: 154 cases including 84 from Beijing and 70 from Tianjin were surveied. 80 cases were positive with haemophilus influenzae nucleic acid in Beijing and 61 cases were positive with haemophilus influenzae nucleic acid in Tianjin. In 141 positive clinical specimens, capsulate and non - capsulate haemophilus influenzae were found in 35 cases and 106 cases, respectively. In 35 cases with capsulate type, 28 specimens were c type and 1 was d type, the rest could not be typed. Conclusion: The noncapsulate type of Haemophilus influenza were mainly carried by the students. In encapsulated strains, c type was the major type carried by the students in Beijing and Tianjin.%目的:监测2009年/2010年北京市和天津市2地在校学生流感嗜血杆菌携带情况.方法:选择北京市和天津市大中小学生上呼吸道感染患者作为监测对象,利用PCR分子生物学技术,对急性上呼吸道患者临床标本进行流感嗜血杆菌核酸检测和血清型分型.结果:共调查了154例上感病例,其中北京84例,天津70例.北京病例标本中共检出流感嗜血杆菌80例,天津病例标本中共检出流感嗜血杆菌61例.141例阳性标本中,非荚膜型106例,荚膜型35例.35例荚膜型中,c型28例,d型1例,另外6例未能分型.结论:北京和天津2地学生主要携带非荚膜型流感嗜血杆菌,携带的荚膜型菌株主要为c型流感嗜血杆菌.

  10. Role of the 145-kilodalton surface protein in virulence of the Brazilian purpuric fever clone of Haemophilus influenzae biogroup aegyptius for infant rats.

    Science.gov (United States)

    Rubin, L G

    1995-09-01

    Brazilian purpuric fever (BPF) is a fulminant infection associated with bacteremia with clonally related strains of Haemophilus influenzae biogroup aegyptius. Case-associated clone strains are more virulent for infant rats than are non-BPF case-associated H. influenzae biogroup aegyptius isolates. I sought to determine the possible role of P145, a 145-kDa surface protein of BPF case H. influenzae biogroup aegyptius clone isolates, in virulence. First, I compared the virulence of two case-associated clone isolates from the blood of children with BPF from Serrana, Brazil, which differed in P145 expression but were identical in all other phenotypic and genotypic characteristics studied. Twenty-four hours after intraperitoneal inoculation of infant rats, there was a significantly higher incidence (51 versus 26%; P = 0.035) and magnitude (2.9 +/- 5.8 versus 0.7 +/- 2.0 CFU/0.01 ml; P = 0.024) of bacteremia in rats inoculated with the P145-expressing strain. I next compared the virulence of a P145-expressing case-associated clone strain with two P145-nonexpressing phase variants of this strain. One variant exhibited a lower mean magnitude of bacteremia and one displayed a similar magnitude of bacteremia compared with that displayed the P145-expressing parental strain. P145-expressing revertants of the P145-nonexpressing strains exhibited the same virulence as the P145-negative variants from which they were derived. Colonies grown from blood cultures maintained the P145 phenotype of the inoculated strain. These results suggest that P145 expression does not contribute to the virulence of the BPF case clone strain for infant rats following intraperitoneal inoculation.

  11. Maturation of molybdoenzymes and its influence on the pathogenesis of non-typeable Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Rabeb eDhouib

    2015-11-01

    Full Text Available Mononuclear molybdenum enzymes of the dimethylsulfoxide (DMSO reductase family occur exclusively in prokaryotes, and a loss of some these enzymes has been linked to a loss of bacterial virulence in several cases. The MobA protein catalyzes the final step in the synthesis of the molybdenum guanine dinucleotide (MGD cofactor that is exclusive to enzymes of the DMSO reductase family. MobA has been proposed as a potential target for control of virulence since its inhibition would affect the activities of all molybdoenzymes dependent upon MGD. Here, we have studied the phenotype of a mobA mutant of the host-adapted human pathogen Haemophilus influenzae. H. influenzae causes and contributes to a variety of acute and chronic diseases of the respiratory tract., and several enzymes of the DMSO reductase family are conserved and highly expressed in this bacterium. The mobA mutation caused a significant decrease in the activities of all Mo-enzymes present, and also resulted in a small defect in anaerobic growth. However, we did not detect a defect in in vitro biofilm formation nor in invasion and adherence to human epithelial cells in tissue culture compared to the wild-type. In a murine in vivo model, the mobA mutant showed only a mild attenuation compared to the wild-type. In summary, our data show that MobA is essential for the activities of molybdenum enzymes, but does not appear to affect the fitness of H. influenzae. These results suggest that MobA is unlikely to be a useful target for antimicrobials, at least for the purpose of treating H. influenzae infections.

  12. Maturation of molybdoenzymes and its influence on the pathogenesis of non-typeable Haemophilus influenzae

    Science.gov (United States)

    Dhouib, Rabeb; Pg Othman, Dk S. M.; Essilfie, Ama-Tawiah; Hansbro, Phil M.; Hanson, Jeffrey O.; McEwan, Alastair G.; Kappler, Ulrike

    2015-01-01

    Mononuclear molybdenum enzymes of the dimethylsulfoxide (DMSO) reductase family occur exclusively in prokaryotes, and a loss of some these enzymes has been linked to a loss of bacterial virulence in several cases. The MobA protein catalyzes the final step in the synthesis of the molybdenum guanine dinucleotide (MGD) cofactor that is exclusive to enzymes of the DMSO reductase family. MobA has been proposed as a potential target for control of virulence since its inhibition would affect the activities of all molybdoenzymes dependent upon MGD. Here, we have studied the phenotype of a mobA mutant of the host-adapted human pathogen Haemophilus influenzae. H. influenzae causes and contributes to a variety of acute and chronic diseases of the respiratory tract, and several enzymes of the DMSO reductase family are conserved and highly expressed in this bacterium. The mobA mutation caused a significant decrease in the activities of all Mo-enzymes present, and also resulted in a small defect in anaerobic growth. However, we did not detect a defect in in vitro biofilm formation nor in invasion and adherence to human epithelial cells in tissue culture compared to the wild-type. In a murine in vivo model, the mobA mutant showed only a mild attenuation compared to the wild-type. In summary, our data show that MobA is essential for the activities of molybdenum enzymes, but does not appear to affect the fitness of H. influenzae. These results suggest that MobA is unlikely to be a useful target for antimicrobials, at least for the purpose of treating H. influenzae infections. PMID:26594204

  13. Haemophilus influenzae infection drives IL-17-mediated neutrophilic allergic airways disease.

    Directory of Open Access Journals (Sweden)

    Ama-Tawiah Essilfie

    2011-10-01

    Full Text Available A subset of patients with stable asthma has prominent neutrophilic and reduced eosinophilic inflammation, which is associated with attenuated airways hyper-responsiveness (AHR. Haemophilus influenzae has been isolated from the airways of neutrophilic asthmatics; however, the nature of the association between infection and the development of neutrophilic asthma is not understood. Our aim was to investigate the effects of H. influenzae respiratory infection on the development of hallmark features of asthma in a mouse model of allergic airways disease (AAD. BALB/c mice were intraperitoneally sensitized to ovalbumin (OVA and intranasally challenged with OVA 12-15 days later to induce AAD. Mice were infected with non-typeable H. influenzae during or 10 days after sensitization, and the effects of infection on the development of key features of AAD were assessed on day 16. T-helper 17 cells were enumerated by fluorescent-activated cell sorting and depleted with anti-IL-17 neutralizing antibody. We show that infection in AAD significantly reduced eosinophilic inflammation, OVA-induced IL-5, IL-13 and IFN-γ responses and AHR; however, infection increased airway neutrophil influx in response to OVA challenge. Augmented neutrophilic inflammation correlated with increased IL-17 responses and IL-17 expressing macrophages and neutrophils (early, innate and T lymphocytes (late, adaptive in the lung. Significantly, depletion of IL-17 completely abrogated infection-induced neutrophilic inflammation during AAD. In conclusion, H. influenzae infection synergizes with AAD to induce Th17 immune responses that drive the development of neutrophilic and suppress eosinophilic inflammation during AAD. This results in a phenotype that is similar to neutrophilic asthma. Infection-induced neutrophilic inflammation in AAD is mediated by IL-17 responses.

  14. Quantitation of antibody-secreting cells in the blood after vaccination with Haemophilus influenzae type b conjugate vaccine

    DEFF Research Database (Denmark)

    Barington, T; Heilmann, C; Andersen, V

    1990-01-01

    The human B-lymphocyte response to protein-conjugated polysaccharide antigens has not previously been studied at the cellular level. In order to do so, we developed and evaluated haemolytic plaque-forming cell assays detecting Haemophilus influenzae type b (Hib) capsular polysaccharide-specific a......The human B-lymphocyte response to protein-conjugated polysaccharide antigens has not previously been studied at the cellular level. In order to do so, we developed and evaluated haemolytic plaque-forming cell assays detecting Haemophilus influenzae type b (Hib) capsular polysaccharide...... capsular polysaccharides from Hib and pneumococci. The predominance of IgA AbSC in response to both conjugate and pure polysaccharide vaccines is probably due to reactivation of the same clones of IgA-committed memory B cells originally primed at the mucosa by natural exposure to the polysaccharide...

  15. Minimal biofilm eradication concentration of antimicrobial agents against nontypeable Haemophilus influenzae isolated from middle ear fluids of intractable acute otitis media.

    Science.gov (United States)

    Takei, Shin; Hotomi, Muneki; Yamanaka, Noboru

    2013-06-01

    Nontypeable Haemophilus influenzae (NTHi) makes the clinical course of acute otitis media (AOM) intractable by forming a biofilm that may hamper the clearance of the bacteria from middle ear cavity. In this study, we evaluated the minimum biofilm eradication concentration (MBEC) of antimicrobial agents against biofilm-forming NTHi strains. Twelve NTHi strains isolated from middle ear fluids of Japanese children with intractable AOM before antimicrobial treatment were evaluated for MBEC of fluoroquinolones in comparison with those of β-lactams and macrolides. AMPC and CDTR required much higher concentration, i.e., high MBECs, to suppress the biofilm formation of NTHi. In contrast, fluoroquinolones followed by macrolides showed lower MBECs. MBEC would be a good parameter to infer the efficacies of antimicrobials against NTHi in biofilm.

  16. Combined Bacteria Microarray and Quartz Crystal Microbalance Approach for Exploring Glycosignatures of Nontypeable Haemophilus influenzae and Recognition by Host Lectins.

    Science.gov (United States)

    Kalograiaki, Ioanna; Euba, Begoña; Proverbio, Davide; Campanero-Rhodes, María A; Aastrup, Teodor; Garmendia, Junkal; Solís, Dolores

    2016-06-01

    Recognition of bacterial surface epitopes by host receptors plays an important role in the infectious process and is intimately associated with bacterial virulence. Delineation of bacteria-host interactions commonly relies on the detection of binding events between purified bacteria- and host-target molecules. In this work, we describe a combined microarray and quartz crystal microbalance (QCM) approach for the analysis of carbohydrate-mediated interactions directly on the bacterial surface, thus preserving the native environment of the bacterial targets. Nontypeable Haemophilus influenzae (NTHi) was selected as a model pathogenic species not displaying a polysaccharide capsule or O-antigen-containing lipopolysaccharide, a trait commonly found in several important respiratory pathogens. Here, we demonstrate the usefulness of NTHi microarrays for exploring the presence of carbohydrate structures on the bacterial surface. Furthermore, the microarray approach is shown to be efficient for detecting strain-selective binding of three innate immune lectins, namely, surfactant protein D, human galectin-8, and Siglec-14, to different NTHi clinical isolates. In parallel, QCM bacteria-chips were developed for the analysis of lectin-binding kinetics and affinity. This novel QCM approach involves capture of NTHi on lectin-derivatized chips followed by formaldehyde fixation, rendering the bacteria an integrated part of the sensor chip, and subsequent binding assays with label-free lectins. The binding parameters obtained for selected NTHi-lectin pairs provide further insights into the interactions occurring at the bacterial surface.

  17. Ultraviolet sensitivity of the addition, deletion and replacement of long nonhomologous DNA segments by genetic transformation of Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Walter, R.B.; Stuy, J.H. (Florida State Univ., Tallahassee (USA). Dept. of Biological Science)

    1982-03-01

    The construction and some properties of Haemophilus influenzae Rd strains with long and different R plasmid-derived DNA segments (nonhomologous inserts) at the same site in the HP1 prophage have previously been described. These inserts can be added to a recipient's genome by genetic transformation, they can be deleted from the recipient genome, or they can be replaced by another insert. It is reported that the UV inactivation of all three phenomena followed single hit kinetics. Deletion was roughly 10 times more resistant; its UV-sensitivity equalled that of a high-efficiency point mutation. There was an inverse correlation between UV-sensitivity and additive transformation efficiency of the various inserts; sensitivity may thus be a measure of insert size. This correlation was not seen for deletion. All three phenomena were more sensitive when they were measured on excision repair-deficient uvr/sup -/ recipients. The dose-reduction factor for addition was about 1.5 while it was about 2.6 for deletion.

  18. Regulation of virulence gene expression resulting from Streptococcus pneumoniae and nontypeable Haemophilus influenzae interactions in chronic disease.

    Directory of Open Access Journals (Sweden)

    Emily K Cope

    Full Text Available Chronic rhinosinusitis (CRS is a common inflammatory disease of the sinonasal cavity mediated, in part, by polymicrobial communities of bacteria. Recent molecular studies have confirmed the importance of Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi in CRS. Here, we hypothesize that interaction between S. pneumoniae and NTHi mixed-species communities cause a change in bacterial virulence gene expression. We examined CRS as a model human disease to validate these polymicrobial interactions. Clinical strains of S. pneumoniae and NTHi were grown in mono- and co-culture in a standard biofilm assay. Reverse transcriptase real-time PCR (RTqPCR was used to measure gene expression of key virulence factors. To validate these results, we investigated the presence of the bacterial RNA transcripts in excised human tissue from patients with CRS. Consequences of physical or chemical interactions between microbes were also investigated. Transcription of NTHi type IV pili was only expressed in co-culture in vitro, and expression could be detected ex vivo in diseased tissue. S. pneumoniae pyruvate oxidase was up-regulated in co-culture, while pneumolysin and pneumococcal adherence factor A were down-regulated. These results were confirmed in excised human CRS tissue. Gene expression was differentially regulated by physical contact and secreted factors. Overall, these data suggest that interactions between H. influenzae and S. pneumoniae involve physical and chemical mechanisms that influence virulence gene expression of mixed-species biofilm communities present in chronically diseased human tissue. These results extend previous studies of population-level virulence and provide novel insight into the importance of S. pneumoniae and NTHi in CRS.

  19. Prevalence of Streptococcus Pneumoniae, Haemophilus Influenzae and Moraxella Catarrhalis in Adenoid Tissues of Children with Adenoid Hypertrophy

    OpenAIRE

    SS Khoramrooz; A. Mirsalehian; Emaneini, M.; A Sharifi; S A Khosravani; Jabalameli, F.; M.Aligholi; D Darban-Sarokhalil; M Mirzaii; A Bazargani

    2012-01-01

    Background & aim: Chronic infection of the adenoid tissue is one of the causes of hypertrophy. Adenoids are considered to be as reservoirs of pathogenic bacteria such as Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae. The aim of this study was to determine the prevalence of mentioned bacteria in children with adenoid hypertrophy. Methods: A total of 113 children with adenoid hypertrophy who underwent adenoidectomy were included in this study. Subsequently, ad...

  20. Structural organization, nucleotide sequence, and regulation of the Haemophilus influenzae rec-1+ gene.

    Science.gov (United States)

    Zulty, J J; Barcak, G J

    1993-11-01

    The Haemophilus influenzae rec-1+ protein plays a central role in DNA metabolism, participating in general homologous recombination, recombinational (postreplication) DNA repair, and prophage induction. Although many H. influenzae rec-1 mutants have been phenotypically characterized, little is known about the rec-1+ gene at the molecular level. In this study, we present the genetic organization of the rec-1+ locus, the DNA sequence of rec-1+, and studies of the transcriptional regulation of rec-1+ during cellular assault by DNA-damaging agents and during the induction of competence for genetic transformation. Although little is known about promoter structure in H. influenzae, we identified a potential rec-1+ promoter that is identical in 11 of 12 positions to the bacterial sigma 70-dependent promoter consensus sequence. Results from a primer extension analysis revealed that the start site of rec-1+ transcription is centered 6 nucleotides downstream of this promoter. We identified potential DNA binding sites in the rec-1+ gene for LexA, integration host factor, and cyclic AMP receptor protein. We obtained evidence that at least one of the proposed cyclic AMP receptor protein binding sites is active in modulating rec-1+ transcription. This finding makes rec-1+ control circuitry novel among recA+ homologs. Two H. influenzae DNA uptake sequences that may function as a transcription termination signal were identified in inverted orientations at the end of the rec-1+ coding sequence. In addition, we report the first use of the Escherichia coli lacZ operon fusion technique in H. influenzae to study the transcriptional control of rec-1+. Our results indicate that rec-1+ is transcriptionally induced about threefold during DNA-damaging events. Furthermore, we show that rec-1+ can substitute for recA+ in E. coli to modulate SOS induction of dinB1 expression. Surprisingly, although 5% of the H. influenzae genome is in the form of single-stranded DNA during competence for

  1. Frequent carriage of resistance mechanisms to beta-lactams and biofilm formation in Haemophilus influenzae causing treatment failure and recurrent otitis media in young children

    NARCIS (Netherlands)

    Garcia-Cobos, Silvia; Moscoso, Miriam; Pumarola, Felix; Arroyo, Margarita; Lara, Noelia; Perez-Vazquez, Maria; Aracil, Belen; Oteo, Jesus; Garcia, Ernesto; Campos, Jose

    2014-01-01

    Objectives: Non-typeable Haemophilus influenzae are a major cause of acute otitis media (AOM), including chronic and recurrent otitis in young children. The objective of this study was to determine whether non-typeable H. influenzae isolates causing these infections produce biofilms and carry resist

  2. Porin OmpP2 of Haemophilus influenzae shows specificity for nicotinamide-derived nucleotide substrates.

    Science.gov (United States)

    Andersen, Christian; Maier, Elke; Kemmer, Gabrielle; Blass, Julia; Hilpert, Anna-Karina; Benz, Roland; Reidl, Joachim

    2003-07-04

    Haemophilus influenzae has an absolute requirement for NAD (factor V) because it lacks all biosynthetic enzymes necessary for de novo synthesis of that cofactor. Therefore, growth in vitro requires the presence of NAD itself, NMN, or nicotinamide riboside (NR). To address uptake abilities of these compounds, we investigated outer membrane proteins. By analyzing ompP2 knockout mutants, we found that NAD and NMN uptake was prevented, whereas NR uptake was not. Through investigation of the properties of purified OmpP2 in artificial lipid membrane systems, the substrate specificity of OmpP2 for NAD and NMN was determined, with KS values of approximately 8 and 4mm, respectively, in 0.1 m KCl, whereas no interaction was detected for the nucleoside NR and other purine or pyrimidine nucleotide or nucleoside species. Based on our analysis, we assume that an intrinsic binding site within OmpP2 exists that facilitates diffusion of these compounds across the outer membrane, recognizing carbonyl and exposed phosphate groups. Because OmpP2 was formerly described as a general diffusion porin, an additional property of acting as a facilitator for nicotinamide-based nucleotide transport may have evolved to support and optimize utilization of the essential cofactor sources NAD and NMN in H. influenzae.

  3. Clinical effects of clarithromycin on persistent inflammation following Haemophilus influenzae-positive acute otitis media.

    Science.gov (United States)

    Iino, Yukiko; Yoshida, Naohiro; Kato, Toshinori; Kakizaki, Keiko; Miyazawa, Tetsuo; Kakuta, Hiroyuki

    2015-03-01

    Additional treatment with clarithromycin (CAM) reduced persistent middle ear inflammation after acute otitis media (AOM) caused by Haemophilus influenzae in children. CAM is a treatment option for persistent inflammation following AOM and to prevent continuing otitis media with effusion. We conducted a clinical study to evaluate a new method of treatment for persistent inflammation after AOM in children. H. influenzae-infected children with AOM were treated acutely with antimicrobial agents, after which those still demonstrating effusion of the middle ear cavity received additional treatment with carbocysteine (S-CMC) alone or S-CMC combined with clarithromycin (CAM) for 1 week. The two regimens were compared in terms of clinical effects. After the initial acute treatment, many patients still showed abnormal otoscopic findings. At the completion of additional treatment, there were no significant differences between the two treatment groups. However, 1 week after completion of additional treatment, the prevalence of a diminished light reflex was significantly lower in the CAM + S-CMC group than in the S-CMC group (p = 0.017). The prevalence of redness of the tympanic membrane also tended to be lower in the combined treatment group than in those receiving a single drug (p = 0.097).

  4. Evidence for covalent attachment of phospholipid to the capsular polysaccharide of Haemophilus influenzae type b

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, J.S.; Doelling, V.W.; Graveline, J.F.; McCoy, D.W.

    1985-08-01

    Cells of Haemophilus influenzae type b were grown in a liquid medium containing (TH)palmitate or ( UC)ribose or both for two generations of exponential growth. Radiolabeled type-specific capsular polysaccharide, polyribosyl ribitol phosphate (PRP), was purified from the culture supernatant by Cetavlon precipitation, ethanol fractionation, and hydroxylapatite and Sepharose 4B chromatography. The doubly labeled ( (TH)palmitate and ( UC)ribose) PRP preparation was found to coelute in a single peak from a Sepharose 4B column, suggesting that both precursors were incorporated into the purified PRP. A singly labeled ( (TH)palmitate) purified PRP preparation was found to be quantitatively immune precipitated by human serum containing antibody against PRP. Only after acid, alkaline, or phospholipase A2 treatment of PRP labeled with (TH)palmitate or (TH)palmitate and ( UC)ribose followed by chloroform-methanol extraction could most of the TH-radioactivity be recovered in the organic phase. The chloroform-soluble acid-hydrolyzed or phospholipase A2-treated product was identified as palmitic acid after thin-layer chromatography. These results strongly suggest that a phospholipid moiety is covalently associated with the H. influenzae type b polysaccharide PRP.

  5. Bacterial Lysis through Interference with Peptidoglycan Synthesis Increases Biofilm Formation by Nontypeable Haemophilus influenzae

    Science.gov (United States)

    Puig, Carmen; Merlos, Alexandra; Viñas, Miguel; de Jonge, Marien I.; Liñares, Josefina; Ardanuy, Carmen

    2017-01-01

    ABSTRACT Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that mainly causes otitis media in children and community-acquired pneumonia or exacerbations of chronic obstructive pulmonary disease in adults. A large variety of studies suggest that biofilm formation by NTHi may be an important step in the pathogenesis of this bacterium. However, the underlying mechanisms involved in this process are poorly elucidated. In this study, we used a transposon mutant library to identify bacterial genes involved in biofilm formation. The growth and biofilm formation of 4,172 transposon mutants were determined, and the involvement of the identified genes in biofilm formation was validated in in vitro experiments. Here, we present experimental data showing that increased bacterial lysis, through interference with peptidoglycan synthesis, results in elevated levels of extracellular DNA, which increased biofilm formation. Interestingly, similar results were obtained with subinhibitory concentrations of β-lactam antibiotics, known to interfere with peptidoglycan synthesis, but such an effect does not appear with other classes of antibiotics. These results indicate that treatment with β-lactam antibiotics, especially for β-lactam-resistant NTHi isolates, might increase resistance to antibiotics by increasing biofilm formation. IMPORTANCE Most, if not all, bacteria form a biofilm, a multicellular structure that protects them from antimicrobial actions of the host immune system and affords resistance to antibiotics. The latter is especially disturbing with the increase in multiresistant bacterial clones worldwide. Bacterial biofilm formation is a multistep process that starts with surface adhesion, after which attached bacteria divide and give rise to biomass. The actual steps required for Haemophilus influenzae biofilm formation are largely not known. We show that interference with peptidoglycan biosynthesis increases biofilm formation because of the release

  6. Prevalence of Streptococcus Pneumoniae, Haemophilus Influenzae and Moraxella Catarrhalis in Adenoid Tissues of Children with Adenoid Hypertrophy

    Directory of Open Access Journals (Sweden)

    SS Khoramrooz

    2012-08-01

    Full Text Available Background & aim: Chronic infection of the adenoid tissue is one of the causes of hypertrophy. Adenoids are considered to be as reservoirs of pathogenic bacteria such as Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae. The aim of this study was to determine the prevalence of mentioned bacteria in children with adenoid hypertrophy. Methods: A total of 113 children with adenoid hypertrophy who underwent adenoidectomy were included in this study. Subsequently, adenoidectomy was performed under general anesthesia. All of the adenoid samples were evaluated for bacterial infection by culture and PCR methods. Results: Streptococcus. pneumoniae was the most common (33.6% bacteria isolated by culture followed by H. influenzae (22.9% and M. catarrhalis (9.7%. PCR method detected S. pneumoniae, H. influenzae and M. catarrhalis in 31%, 29.2% and 9.7% of samples respectively. Conclusion: Streptococcus. Pneumonia, H. influenzae and M. catarrhalis are isolated with different frequency in patients with adenoid hypertrophy.

  7. Beta- lactam antibiotics stimulate biofilm formation in non-typeable haemophilus influenzae by up-regulating carbohydrate metabolism.

    Directory of Open Access Journals (Sweden)

    Siva Wu

    Full Text Available 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.

  8. Beta- lactam antibiotics stimulate biofilm formation in non-typeable haemophilus influenzae by up-regulating carbohydrate metabolism.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  10. LytM Proteins Play a Crucial Role in Cell Separation, Outer Membrane Composition, and Pathogenesis in Nontypeable Haemophilus influenzae

    Science.gov (United States)

    Ercoli, Giuseppe; Tani, Chiara; Pezzicoli, Alfredo; Vacca, Irene; Martinelli, Manuele; Pecetta, Simone; Petracca, Roberto; Rappuoli, Rino; Pizza, Mariagrazia; Soriani, Marco

    2015-01-01

    ABSTRACT LytM proteins belong to a family of bacterial metalloproteases. In Gram-negative bacteria, LytM factors are mainly reported to have a direct effect on cell division by influencing cleavage and remodeling of peptidoglycan. In this study, mining nontypeable Haemophilus influenzae (NTHI) genomes, three highly conserved open reading frames (ORFs) containing a LytM domain were identified, and the proteins encoded by the ORFs were named YebA, EnvC, and NlpD on the basis of their homology with the Escherichia coli proteins. Immunoblotting and confocal analysis showed that while NTHI NlpD is exposed on the bacterial surface, YebA and EnvC reside in the periplasm. NTHI ΔyebA and ΔnlpD deletion mutants revealed an aberrant division phenotype characterized by an altered cell architecture and extensive membrane blebbing. The morphology of the ΔenvC deletion mutant was identical to that of the wild-type strain, but it showed a drastic reduction of periplasmic proteins, including the chaperones HtrA, SurA, and Skp, and an accumulation of β-barrel-containing outer membrane proteins comprising the autotransporters Hap, IgA serine protease, and HMW2A, as observed by proteomic analysis. These data suggest that EnvC may influence the bacterial surface protein repertoire by facilitating the passage of the periplasmic chaperones through the peptidoglycan layer to the close vicinity of the inner face of the outer membrane. This hypothesis was further corroborated by the fact that an NTHI envC defective strain had an impaired capacity to adhere to epithelial cells and to form biofilm. Notably, this strain also showed a reduced serum resistance. These results suggest that LytM factors are not only important components of cell division but they may also influence NTHI physiology and pathogenesis by affecting membrane composition. PMID:25714719

  11. Will the swine strain crowd out the seasonal influenza strain?

    CERN Document Server

    Schinazi, Rinaldo B

    2010-01-01

    We use spatial and non spatial models to argue that competition alone may explain why two influenza strains do not usually coexist. The more virulent strain is likely to crowd out the less virulent one. This can be seen as a consequence of the Exclusion Principle of Ecology. We exhibit, however, a spatial model for which coexistence is possible.

  12. 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.

    Science.gov (United States)

    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.

  13. Genes from plasmid pKM101 in Haemophilus influenzae: separation of functions of mucA and mucB

    Energy Technology Data Exchange (ETDEWEB)

    Balganesh, M.; Setlow, J.K.

    1985-11-01

    Haemophilus influenzae, normally not mutable by UV, became UV mutable with a recombinant plasmid insertion. A 7.8-kilobase-pair (kbp) fragment of the plasmid pKM101 containing the mucA and mucB genes was ligated to the shuttle vector pDM2, and a Rec- strain of H. influenzae was transformed with the ligated mixture. All of the transformants, unlike the parent Rec- strain, were resistant to UV, could carry out postreplication repair and Weigle reactivation, showed greatly increased spontaneous mutation, and contained a plasmid carrying an insert of only 1.2 rather than 7.8 kbp. This plasmid in a umuC mutant strain of Escherichia coli complemented a pKM101 derivative lacking mucA function but with an intact mucB gene, although there was no complementation with a mucA+ mucB- plasmid, suggesting that the newly constructed plasmid coded for the mucA protein; this is in accord with the restriction analysis and hybridization between the plasmid and a probe containing all of the mucA gene but only a small fraction of mucB. When one of the H. influenzae Rec- transformants lost the plasmid, the resistance to UV was retained but the high spontaneous mutation and UV mutability were not. The fact that there was hybridization between the chromosome of the cured strain and a probe containing both muc genes but none when almost no mucB was present suggested that at least part of the mucB gene had been integrated into the Rec- chromosome. Five different postreplication repair-proficient strains became UV mutable and had high spontaneous mutation rates caused by the putative mucA plasmid, indicating that these strains already possessed a chromosomal equivalent of the mucB gene.

  14. Distribution and drug resistance analysis of Streptococcus pneumonia and Haemophilus influenzae%肺炎链球菌和流感嗜血杆菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    宁静; 韦桂雪

    2013-01-01

    . The resistance rates of Haemophilus influenzae to ampicillin、cotrimoxazole and cefuroxime were high, and 64.17%Haemophilus influenzae producedβ-lactamase. The resistance rates of Streptococcus pneumoniae to erythromycin、chloramphenicol、tetracycline、clindamycin were serious, and there were 47 (56.63%) isolates of Streptococcus pneumoniae were penicillin non-susceptible (PNSP). Conclusions:The resistance of Haemophilus influenzae and Streptococcus pneumoniae were serious. Monitoring the resistance of Haemophilus influenzae and Streptococcus pneumoniae will help to reduce the generation of resistant strains.

  15. Progress of Haemophilus influenzae type a and related vaccine%a 型流感嗜血杆菌及其疫苗的研究进展

    Institute of Scientific and Technical Information of China (English)

    苗鑫(综述); 谢贵林; 赵志强(审校)

    2016-01-01

    随着b型流感嗜血杆菌(Haemophilus influenzae type b, Hib)结合疫苗在全球的广泛应用,Hib相关疾病的发病率明显下降;a型流感嗜血杆菌( Haemophilus influenzae type a, Hia)逐渐成为侵袭性流感嗜血杆菌疾病的重要病原体,且因其发病率高、临床症状重、死亡率高而日益受到关注。本文从Hia的流行概况、相关疾病、药物敏感性、易感人群及其疫苗研究作一综述。%The morbidity of Haemophilus influenzae type b( Hib) related diseases has reduced substantially,since Hib conju-gate vaccines were widely used all over the world.However,Haemophilus influenzae type a ( Hia) has become an important pathogen that causes invasive Haemophilus influenzae diseases, and been concerned with a high incidence for the related diseases, severe clinical symptoms and a high mortality, increasingly.We review epidemiology, related diseases, antibiotic susceptibility, susceptible population and related vaccine research of Hia diseases.

  16. Bactericidal activities of parenteral antibiotics and genotype of penicillin-binding protein in Streptococcus pneumoniae and Haemophilus influenzae isolated from children's blood.

    Science.gov (United States)

    Sakata, Hiroshi

    2006-10-01

    A total of 16 isolates of Streptococcus pneumoniae and 18 isolates of Haemophilus influenzae were obtained from the blood of children admitted to the pediatric wards of hospitals in Hokkaido Kamikawa subprefecture between January 2003 and December 2005. The ages of the patients with S. pneumoniae or H. influenzae infection ranged from 2 months to 9 years and from 1 month to 4 years, respectively. The diagnoses of S. pneumoniae infection were as follows: pneumonia in 8 patients, occult bacteremia in 5 patients, and meningitis in 3 patients. The diagnoses of H. influenzae were: meningitis in 6 patients, pneumonia in 4 patients, occult bacteremia in 4 patients, epiglotitis in 2 patients, and facial cellulitis in 2 patients. Out of 16 S. pneumoniae isolates, penicillin-resistant strains with a mutation of 3 genes were observed in 7 children, and penicillin intermediate-resistant strains with a mutation of 1 or 2 genes were observed in 8 children. Out of 18 H. influenzae isolates, the beta-lactamase-negative ampicillin-resistant strain with a substitution of 2 points in the ftsI gene was revealed in 2 children, the beta-lactamase-negative ampicillin-resistant strain with a substitution of 1 point in the ftsI gene was observed in 4 children, the beta-lactamase-positive amoxicillin/clavulanic acid-resistant strain with blaTEM-1 and ftsI with 2 substitutions in the ftsI gene was observed in 3 children, and the beta-lactamase-positive ampicillin-resistant strain with blaTEM-1was not observed. The MBC90s of ampicillin, ceftriaxone, cefotaxime, meropenem, panipenem, and vancomycin against S. pneumoniae were 8 microg/ml, 1 microg/ml, 1 microg/ml 1 microg/ml, 0.25 microg/ml, and 0.5 microg/ml, respectively. Those of ampicillin, piperacillin, ceftriaxone, cefotaxime, meropenem, and panipenem against H. influenzae were >128 microg/ml, >128 microg/ml, 0.25 microg/mL, 1 microg/ml, 0.12 microg/ml, and 0.5 g/ml, respectively. It is suggest that the minimum bactricidal concentration

  17. Diversion of the host humoral response: a novel virulence mechanism of Haemophilus influenzae mediated via outer membrane vesicles.

    Science.gov (United States)

    Deknuydt, Florence; Nordström, Therése; Riesbeck, Kristian

    2014-06-01

    The respiratory tract pathogen Haemophilus influenzae frequently causes infections in humans. In parallel with all Gram-negative bacteria, H. influenzae has the capacity to release OMV. The production of these nanoparticles is an intriguing and partly unexplored phenomenon in pathogenesis. Here, we investigated how purified human peripheral blood B lymphocytes respond to OMV derived from unencapsulated, i.e., NTHi and the nonpathogenic Haemophilus parainfluenzae. We found that H. influenzae OMV directly interacted with the IgD BCR, as revealed by anti-IgD pAb and flow cytometry. Importantly, H. influenzae OMV-induced cellular activation via IgD BCR cross-linking and TLR9 resulted in a significant proliferative response. OMV isolated from the related species H. parainfluenzae did not, however, interact with B cells excluding that the effect by H. influenzae OMV was linked to common membrane components, such as the LOS. We also observed an up-regulation of the cell surface molecules CD69 and CD86, and an increased IgM and IgG secretion by B cells incubated with H. influenzae OMV. The Igs produced did not recognize H. influenzae, suggesting a polyclonal B cell activation. Interestingly, the density of the cell surface receptor TACI was increased in the presence of OMV that sensitized further the B cells to BAFF, resulting in an enhanced IgG class-switch. In conclusion, the ability of NTHi OMV to activate B cells in a T cell-independent manner may divert the adaptive humoral immune response that consequently promotes bacterial survival within the human host. © 2014 Society for Leukocyte Biology.

  18. Trends in the epidemiology of invasive Haemophilus influenzae disease in Queensland, Australia from 2000 to 2013: what is the impact of an increase in invasive non-typable H. influenzae (NTHi)?

    Science.gov (United States)

    Wan Sai Cheong, J; Smith, H; Heney, C; Robson, J; Schlebusch, S; Fu, J; Nourse, C

    2015-10-01

    Following the introduction of vaccination against Haemophilus influenzae type b (Hib), cases of invasive encapsulated Hib disease have decreased markedly. This study aimed to examine subsequent epidemiological trends in invasive H. influenzae disease in Queensland, Australia and in particular, assess the clinical impact and public health implications of invasive non-typable H. influenzae (NTHi) strains. A multicentre retrospective study was conducted from July 2000 to June 2013. Databases of major laboratories in Queensland including Queensland Forensic and Scientific Services (jurisdictional referral laboratory for isolate typing) were examined to identify cases. Demographic, infection site, Indigenous status, serotype, and mortality data were collected. In total, 737 invasive isolates were identified, of which 586 (79·5%) were serotyped. Hib, NTHi and encapsulated non-b strains, respectively, constituted 12·1%, 69·1% and 18·8% of isolates. The predominant encapsulated non-b strains were f (45·5%) and a (27·3%) serotypes. Of isolates causing meningitis, 48·9% were NTHi, 14·9% Hib, 14·9% Hie, 10·6% Hif, 6·4% Hia and 4·3% were untyped. During the study period, there was an increase in the incidence of invasive NTHi disease (P = 0·007) with seasonal peaks in winter and spring (P 0·001) and Hib (P = 0·039) than non-Indigenous patients. In Queensland, invasive H. influenzae disease is now predominantly encountered in adults and most commonly caused by NTHi strains with demonstrated pathogenicity extending to otherwise young or immunocompetent individuals. Routine public health notification of these strains is recommended and recent available immunization options should be considered.

  19. Comparison of lipopolysaccharides from Brazilian purpuric fever isolates and conjunctivitis isolates of Haemophilus influenzae biogroup aegyptius. Brazilian Purpuric Fever Study Group.

    Science.gov (United States)

    Erwin, A L; Munford, R S

    1989-04-01

    Haemophilus influenzae biogroup aegyptius (H. aegyptius) has been identified as the etiologic agent of the recently described disease Brazilian purpuric fever (BPF). Although there is heterogeneity among the strains associated with conjunctivitis, isolates from patients with BPF appear to be derived from a single clone. The clinical presentation of BPF suggests that bacterial lipopolysaccharides (LPS) are involved in its pathogenesis. We prepared LPS from H. influenzae biogroup aegyptius and found them to be similar to H. influenzae type b LPS in apparent size (by sodium dodecyl sulfate-polyacrylamide gel electrophoresis), biological activities, and fatty acid composition. We compared LPS from BPF clone isolates with LPS from non-BPF clone isolates in tests of Limulus lysate activation, spleen cell mitogenesis, promotion of neutrophil adherence to LPS-treated endothelial cells, and the dermal Shwartzman reaction. In none of these activities were LPS from the BPF clone isolates more potent. Because LPS shed from growing bacteria may be involved in the pathogenesis of purpura, we also measured the rate at which LPS were released into culture medium during bacterial growth and found no significant difference between BPF clone and non-BPF clone isolates.

  20. Streptococcus pneumoniae and Haemophilus influenzae as etiological agents of conjunctivitis outbreaks in the region of Ribeirão Preto, SP, Brazil

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    Marta I. C. MEDEIROS

    1998-01-01

    Full Text Available In the study of conjunctivitis outbreaks occurring from September 1994 to September 1996 in the region of Ribeirão Preto, conjunctival exudates of 92 patients were cultivated in Instituto Adolfo Lutz Laboratory I, Ribeirão Preto. Most cases occurred in the age range 2-7 years. The etiological agents which were most frequently isolated from the analyzed cases were: Streptococcus pneumoniae and Haemophilus influenzae, in 40.22% and 21.74%, respectively. 51.35% of the S. pneumoniae isolated strains were not typable. The oxacillin-resistant S. pneumoniae strains were submitted to the minimum inhibitory concentration test (MIC and three of them presented intermediate resistance, whereas only one was highly resistant to penicillin.No estudo de surtos de conjuntivite ocorridos no período de setembro de 1994 a setembro de 1996, na região de Ribeirão Preto, foram semeadas no Instituto Adolfo Lutz Laboratório I, Ribeirão Preto, exsudatos conjuntivais de 92 pacientes, sendo que a maioria dos casos estava na faixa etária de 2-7 anos. Os agentes etiológicos mais freqüentemente isolados dos casos analisados foram: Streptococcus pneumoniae e Haemophilus influenzae em 40,22% e 21,74% respectivamente. 51,35% das cepas de S. pneumoniae isoladas foram não tipáveis. As cepas de S. pneumoniae oxacilina resistente foram submetidas ao teste de concentração inibitória mínima (CIM, sendo que três apresentaram resistência intermediária e apenas uma foi altamente resistente à penicilina.

  1. Invasive polyarticular septic arthritis caused by nontypeable haemophilus influenzae in a young adult: a case report and literature review.

    Science.gov (United States)

    Kim, Jong Hun; Muto, Carlene A; Pasculle, A William; Vergis, Emanuel N

    2011-10-01

    Nontypeable Haemophilus influenzae is a rare cause of septic arthritis in adults and has been reported to be associated with underlying medical conditions. We present a case of nontypeable H. influenzae-infected severe invasive polyarticular septic arthritis in a young adult without any underlying predisposing medical conditions. Diagnosis was made from both positive blood culture and joint aspiration culture. The patient was successfully treated with employment of aggressive surgical debridement of multiple affected septic joints as well as prolonged antibiotic treatment. Further laboratory testing did not reveal significant underlying medical conditions including negative HIV, normal levels of complement and IgG subclasses, and normal-appearing spleen on computed tomography. This case illustrates that nontypeable H. influenzae can cause serious invasive septic arthritis infection in both patients with and without predisposing underlying medical conditions and that prompt diagnosis with aggressive treatment of combined surgical and medical treatment can result in optimal recovery.

  2. Characterization of the rec-1 gene of Haemophilus influenzae and behavior of the gene in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.; Spikes, D.; Griffin, K.

    1988-09-01

    The rec-1 gene of Haemophilus influenzae was cloned into a shuttle vector that replicates in Escherichia coli as well as in H. influenzae. The plasmid, called pRec1, complemented the defects of a rec-1 mutant in repair of UV damage, transformation, and ability of prophage to be induced by UV radiation. Although UV resistance and recombination were caused by pRec1 in E. coli recA mutants, UV induction of lambda and UV mutagenesis were not. We suggest that the ability of the H. influenzae Rec-1 protein to cause cleavage of repressors but not the recombinase function differs from that of the E. coli RecA protein.

  3. The genome-scale metabolic extreme pathway structure in Haemophilus influenzae shows significant network redundancy.

    Science.gov (United States)

    Papin, Jason A; Price, Nathan D; Edwards, Jeremy S; Palsson B, Bernhard Ø

    2002-03-07

    Genome-scale metabolic networks can be characterized by a set of systemically independent and unique extreme pathways. These extreme pathways span a convex, high-dimensional space that circumscribes all potential steady-state flux distributions achievable by the defined metabolic network. Genome-scale extreme pathways associated with the production of non-essential amino acids in Haemophilus influenzae were computed. They offer valuable insight into the functioning of its metabolic network. Three key results were obtained. First, there were multiple internal flux maps corresponding to externally indistinguishable states. It was shown that there was an average of 37 internal states per unique exchange flux vector in H. influenzae when the network was used to produce a single amino acid while allowing carbon dioxide and acetate as carbon sinks. With the inclusion of succinate as an additional output, this ratio increased to 52, a 40% increase. Second, an analysis of the carbon fates illustrated that the extreme pathways were non-uniformly distributed across the carbon fate spectrum. In the detailed case study, 45% of the distinct carbon fate values associated with lysine production represented 85% of the extreme pathways. Third, this distribution fell between distinct systemic constraints. For lysine production, the carbon fate values that represented 85% of the pathways described above corresponded to only 2 distinct ratios of 1:1 and 4:1 between carbon dioxide and acetate. The present study analysed single outputs from one organism, and provides a start to genome-scale extreme pathways studies. These emergent system-level characterizations show the significance of metabolic extreme pathway analysis at the genome-scale.

  4. Proteomic expression profiling of Haemophilus influenzae grown in pooled human sputum from adults with chronic obstructive pulmonary disease reveal antioxidant and stress responses

    Directory of Open Access Journals (Sweden)

    Brauer Aimee L

    2010-06-01

    Full Text Available Abstract Background Nontypeable Haemophilus influenzae colonizes and infects the airways of adults with chronic obstructive pulmonary disease, the fourth most common cause of death worldwide.Thus, H. influenzae, an exclusively human pathogen, has adapted to survive in the hostile environment of the human airways.To characterize proteins expressed by H. influenzae in the airways, a prototype strain was grown in pooled human sputum to simulate conditions in the human respiratory tract.The proteins from whole bacterial cell lysates were solubilized with a strong buffer and then quantitatively cleaned with an optimized precipitation/on-pellet enzymatic digestion procedure.Proteomic profiling was accomplished by Nano-flow liquid chromatography/mass spectroscopy with low void volume and high separation efficiency with a shallow, long gradient. Results A total of 1402 proteins were identified with high confidence, including 170 proteins that were encoded by genes that are annotated as conserved hypothetical proteins.Thirty-one proteins were present in greater abundance in sputum-grown conditions at a ratio of > 1.5 compared to chemically defined media.These included 8 anti-oxidant and 5 stress-related proteins, suggesting that expression of antioxidant activity and stress responses is important for survival in the airways.Four proteins involved in uptake of divalent anions and 9 proteins that function in uptake of various molecules were present in greater abundance in sputum-grown conditions. Conclusions Proteomic expression profiling of H. influenzae grown in pooled human sputum revealed increased expression of antioxidant, stress-response proteins and cofactor and nutrient uptake systems compared to media grown cells.These observations suggest that H. influenzae adapts to the oxidative and nutritionally limited conditions of the airways in adults with chronic obstructive pulmonary disease by increasing expression of molecules necessary for survival

  5. 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.

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    Hagen Frickmann

    Full Text Available 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.

  6. Nontypeable Haemophilus influenzae in chronic obstructive pulmonary disease and lung cancer

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    Seyed Javad Moghaddam

    2011-01-01

    Full Text Available Seyed Javad Moghaddam1, Cesar E Ochoa1,2, Sanjay Sethi3, Burton F Dickey1,41Department of Pulmonary Medicine, the University of Texas MD Anderson Cancer Center, Houston, TX, USA; 2Tecnológico de Monterrey School of Medicine, Monterrey, Nuevo León, Mexico; 3Department of Medicine, University at Buffalo, State University of New York, Buffalo, NY, USA; 4Center for Inflammation and Infection, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USAAbstract: Chronic obstructive pulmonary disease (COPD is predicted to become the third leading cause of death in the world by 2020. It is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles and gases, most commonly cigarette smoke. Among smokers with COPD, even following withdrawal of cigarette smoke, inflammation persists and lung function continues to deteriorate. One possible explanation is that bacterial colonization of smoke-damaged airways, most commonly with nontypeable Haemophilus influenzae (NTHi, perpetuates airway injury and inflammation. Furthermore, COPD has also been identified as an independent risk factor for lung cancer irrespective of concomitant cigarette smoke exposure. In this article, we review the role of NTHi in airway inflammation that may lead to COPD progression and lung cancer promotion.Keywords: COPD, NTHi, inflammation

  7. In vitro interference of cefotaxime at subinhibitory concentrations on biofilm formation by nontypeable Haemophilus influenzae

    Institute of Scientific and Technical Information of China (English)

    Sudarat Baothong; Sutthirat Sitthisak; Duangkamol Kunthalert

    2016-01-01

    Objective: To investigate the in vitro interference of cefotaxime at subinhibitory con-centrations [sub-minimal inhibitory concentrations (MIC)] on biofilm formation by nontypeable Haemophilus influenzae (NTHi). Methods: The interference of subinhibitory concentrations of cefotaxime on biofilm formation of the clinical strong-biofilm forming isolates of NTHi was evaluated by a microtiter plate biofilm formation assay. The effect of sub-MIC cefotaxime on bacterial cell-surface hydrophobicity was determined using a standard microbial adhesion to n-hexadecane test. Additionally, the effects on bacterial adherence to human fibronectin and expression of bacterial adhesins were also investigated. Results: Subinhibitory concentrations of cefotaxime, both at 0.1× and 0.5× MIC levels, efficiently reduced the NTHi biofilm formation, and this effect was independent of decreasing bacterial viability. Sub-MIC cefotaxime also decreased bacterial cell-surface hydrophobicity and reduced adherence to human fibronectin. Inhibition in the P2 and P6 gene expressions upon exposure to sub-MIC cefotaxime was also noted. Conclusions: Taken together, our results indicate that sub-MIC cefotaxime interferes with the formation of NTHi biofilm, and this effect is feasibly related to the interference with cell-surface hydrophobicity, fibronectin-binding activity as well as alteration of the P2 and P6 gene expression. The findings of the present study therefore provide a rationale for the use of subinhibitory concentrations of cefotaxime for treatment of NTHi-related diseases.

  8. Nontypeable Haemophilus influenzae induces sustained lung oxidative stress and protease expression.

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    Paul T King

    Full Text Available 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.

  9. Study on Haemophilus influenzae type b diseases in China: the past, present and future.

    Science.gov (United States)

    Yang, Y; Shen, X; Jiang, Z; Liu, X; Leng, Z; Lu, D; Rao, J; Liu, J; Chang, L

    1998-09-01

    Meningitis caused by Haemophilus influenzae type b (Hib) is a common and serious disease for which there now are WHO-certified vaccines that are recommended for universal infant immunization in North America and European countries. If these vaccines are to be recommended in Asia, it is necessary to know the incidence, age distribution and clinical outcome of Hib meningitis and other systemic infections in this region. Data on Hib disease in China are scanty. Hib meningitis was common during the 1950s in China, accounting for up to 16% of all of pyogenic meningitis (up to 38% of cases were caused by unknown pathogens), despite severe epidemics of meningococcal meningitis during that period. Since 1989 we have conducted hospital- and community-based etiologic and epidemiologic studies of bacterial meningitis. Hib accounts for 30 to 50% of bacterial meningitis in China. The incidence of Hib meningitis in Hefei City was 10.4 per 100000 children death rate of children by one-third by the year 2000, greater efforts should be made to reduce the mortality of children with pneumonia. Our preliminary study showed that about one-fourth to one-third of cases of pneumonia in Chinese children might be caused by Hib. Therefore Hib vaccination for infants and children in China might be an effective and valuable procedure to achieve the goal.

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

    Science.gov (United States)

    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

  11. Development and technology transfer of Haemophilus influenzae type b conjugate vaccines for developing countries.

    Science.gov (United States)

    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.

  12. Recognition of nucleoside monophosphate substrates by Haemophilus influenzae class C acid phosphatase.

    Science.gov (United States)

    Singh, Harkewal; Schuermann, Jonathan P; Reilly, Thomas J; Calcutt, Michael J; Tanner, John J

    2010-12-10

    The e (P4) phosphatase from Haemophilus influenzae functions in a vestigial NAD(+) utilization pathway by dephosphorylating nicotinamide mononucleotide to nicotinamide riboside. P4 is also the prototype of class C acid phosphatases (CCAPs), which are nonspecific 5',3'-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'-AMP, 3'-AMP, and 2'-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 pockets 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'-nucleotides and 3'-nucleotides. These pockets minimize the enzyme's direct interactions with the ribose and provide sufficient space to accommodate 5' substrates in an anti conformation and 3' substrates in a syn conformation. Finally, the structures suggest that class B acid phosphatases and CCAPs share a common strategy for nucleotide recognition.

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

    Science.gov (United States)

    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.

  14. Transcriptome signature in young children with acute otitis media due to non-typeable Haemophilus influenzae.

    Science.gov (United States)

    Liu, Keyi; Chen, Linlin; Kaur, Ravinder; Pichichero, Michael E

    2013-06-01

    Non-typeable Haemophilus influenzae (NTHi) causes acute otitis media (AOM) in young children. In our recent paper in Microbes and Infection we described the transcriptome signature elicited from PBMCs at onset of AOM caused by Streptococcus pneumoniae. In the current study we found very different results with NTHi AOM infections; 5.1% of 29 187 genes were differentially regulated by more than 2-fold at the onset of AOM compared with the pre-infection healthy state in the same children. Among the 1487 transcripts, 100 genes associated with the immune defense response were specifically analyzed. About half of the differentially regulated genes associated with antibacterial activity and the cell-mediated immune response were activated and half were suppressed. The important signatures for NTHi in children suggested that the balance of the immune response was toward suppression. Moreover, 90% of the genes associated with a pro-inflammatory cytokine response were down-regulated. The genes associated with the classic complement pathway were down-regulated, although the alternative complement pathway genes were up-regulated. These results provide the first human transcriptome data identifying gene expression in the immune response to be predominantly down-regulated at the onset of AOM due to NTHi.

  15. Regulation of the vapBC-1 toxin-antitoxin locus in nontypeable Haemophilus influenzae.

    Directory of Open Access Journals (Sweden)

    Susan D Cline

    Full Text Available Nontypeable Haemophilus influenzae (NTHi are human-adapted commensal bacteria that can cause a number of chronic mucosal infections, including otitis media and bronchitis. One way for these organisms to survive antibiotic therapy and cause recurrent disease is to stop replicating, as most antimicrobials target essential biosynthetic pathways. Toxin-antitoxin (TA gene pairs have been shown to facilitate entry into a reversible bacteriostatic state. Characteristically, these operons encode a protein toxin and an antitoxin that associate following translation to form a nontoxic complex, which then binds to and regulates the cognate TA promoter. Under stressful conditions, the labile antitoxin is degraded and the complex disintegrates, freeing the stable toxin to facilitate growth arrest. How these events affected the regulation of the TA locus, as well as how the transcription of the operon was subsequently returned to its normal state upon resumption of growth, was not fully understood. Here we show that expression of the NTHi vapBC-1 TA locus is repressed by a complex of VapB-1 and VapC-1 under conditions favorable for growth, and activated by the global transactivator Factor for Inversion Stimulation (Fis upon nutrient upshift from stationary phase. Further, we demonstrate for the first time that the VapC-1 toxin alone can bind to its cognate TA locus control region and that the presence of VapB-1 directs the binding of the VapBC-1 complex in the transcriptional regulation of vapBC-1.

  16. Genotypic and phenotypic diversity of the noncapsulated Haemophilus influenzae: adaptation and pathogenesis in the human airways.

    Science.gov (United States)

    Garmendia, Junkal; Martí-Lliteras, Pau; Moleres, Javier; Puig, Carmen; Bengoechea, José A

    2012-12-01

    The human respiratory tract contains a highly adapted microbiota including commensal and opportunistic pathogens. Noncapsulated or nontypable Haemophilus influenzae (NTHi) is a human-restricted member of the normal airway microbiota in healthy carriers and an opportunistic pathogen in immunocompromised individuals. The duality of NTHi as a colonizer and as a symptomatic infectious agent is closely related to its adaptation to the host, which in turn greatly relies on the genetic plasticity of the bacterium and is facilitated by its condition as a natural competent. The variable genotype of NTHi accounts for its heterogeneous gene expression and variable phenotype, leading to differential host-pathogen interplay among isolates. Here we review our current knowledge of NTHi diversity in terms of genotype, gene expression, antigenic variation, and the phenotypes associated with colonization and pathogenesis. The potential benefits of NTHi diversity studies discussed herein include the unraveling of pathogenicity clues, the generation of tools to predict virulence from genomic data, and the exploitation of a unique natural system for the continuous monitoring of long-term bacterial evolution in human airways exposed to noxious agents. Finally, we highlight the challenge of monitoring both the pathogen and the host in longitudinal studies, and of applying comparative genomics to clarify the meaning of the vast NTHi genetic diversity and its translation to virulence phenotypes.

  17. Structural Analysis of Substrate, Reaction Intermediate, and Product Binding in Haemophilus influenzae Biotin Carboxylase.

    Science.gov (United States)

    Broussard, Tyler C; Pakhomova, Svetlana; Neau, David B; Bonnot, Ross; Waldrop, Grover L

    2015-06-23

    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.

  18. The molybdate binding protein Mop from Haemophilus influenzae--biochemical and thermodynamic characterisation.

    Science.gov (United States)

    Masters, Seth L; Howlett, Geoffrey J; Pau, Richard N

    2005-07-01

    The protein Mop from Haemophilus influenzae is a member of the molbindin family of proteins. Using isothermal titration calorimetry (ITC), Mop was observed to bind molybdate at two distinct sites with a stoichiometry of 8 mol molybdate per Mop hexamer. Six moles of molybdate bound endothermically at high affinity sites (K(a)=8.5 x 10(7)M(-1)), while 2 mol of molybdate bound exothermically at lower affinity sites (K(a)=3.7 x 10(7)M(-1)). Sulphate was also found to bind weakly at the higher affinity sites. ITC revealed that the affinity of molybdate binding to the endothermic site decreased with increasing pH and was accompanied by the transfer from the buffer to the protein of one proton per Mop monomer. These kinetic and thermodynamic results are interpreted with reference to molbindin crystal structures and data concerning molbindin binding affinities. Mop binds molybdate with high specificity, capacity, and affinity which indicates that Mop has a role as an intracellular molybdate binding protein involved in oxyanion homeostasis.

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

    Science.gov (United States)

    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

  20. Attempts to induce mutations in Haemophilus influenzae with the base analogues 5-bromodeoxyuridine and 2-aminopurine

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, R.F.; Perdue, S.W.

    1977-01-01

    Attempts were made to induce mutations in Haemophilus influenzae with the base analogues 5-bromodeoxyuridine and 2-aminopurine. These attempts were unsuccessful. Incorporation studies with BrdUrd showed, in agreement with earlier studies on Escherichia coli, that BrdUrd was discriminated against when dThd was also present but was incorporated to essentially the same extent as dThd when only BrdUrd was present. In this latter case, strands fully substituted with BrdUrd were produced, but survival data suggest that bacteria deriving their DNA by replication on such fully substituted templates were inviable. However, bacteria with about 20% of the thymine substituted with bromouracil were usually viable. No mutations could be detected in the descendants of such bacteria. The reasons for this are discussed and it is concluded that in all probability the replication system in species rarely if ever treats incorporated bromouracil as anything except a thymine analogue. The alternative possibility, that the negative results are a consequence of the absence of the reclex (SOS) error-prone repair system in this species, is considered much less likely.

  1. Streptococcus pneumoniae synergizes with nontypeable Haemophilus influenzae to induce inflammation via upregulating TLR2

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    Kweon Soo-Mi

    2008-07-01

    Full Text Available Abstract Background Toll-like receptor 2 (TLR2 plays a critical role in mediating inflammatory/immune responses against bacterial pathogens in lung. Streptococcus pneumoniae (S. pneumoniae and nontypeable Haemophilus influenzae (NTHi were previously reported to synergize with each other to induce inflammatory responses. Despite the relatively known intracellular signaling pathways involved in the synergistic induction of inflammation, it is still unclear if both bacterial pathogens also synergistically induce expression of surface TLR2. Results Here we provide direct evidence that S. pneumoniae synergizes with NTHi to upregulate TLR2 expression in lung and middle ear of the mice. Pneumolysin (PLY appears to be the major virulence factor involved in this synergism. Moreover, S. pneumoniae PLY induces TLR2 expression via a TLR4-MyD88-NF-κB-dependent signaling pathway. Interestingly, tumor suppressor CYLD acts as a negative regulator of S. pneumoniae-induced TLR2 up-regulation via negative-crosstalk with NF-κB signaling. Conclusion Our study thus provides novel insights into the regulation of TLR2 expression in mixed bacterial infections.

  2. Single-stranded regions in transforming deoxyribonucleic acid after uptake by competent Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Sedgwick, B.; Setlow, J.K.

    1976-02-01

    About 15% of donor deoxyribonucleic acid (DNA) is single stranded immediately after uptake into competent Haemophilus influenzae wild-type cells, as judged by its sensitivity to S1 endonuclease. This amount decreases to 4 to 5% by 30 min after uptake. Mutants which are defective in the covalent association of recipient and donor DNA form little or no S1 endonuclease-sensitive donor. At 17 C donor DNA taken up by the wild type contains single-stranded regions although there is no observable association, either covalent or noncovalent. The single-stranded regions are at the ends of donor DNA molecules, as judged by the unchanged sedimentation velocity after S1 endonuclease digestion. The amount of single-stranded donor remains constant at 17 C for more than 60 min after uptake, suggesting that the decrease observed at 37 C is the result of association of single-stranded ends with single-stranded regions of recipient cell DNA. Three sequential steps necessary for the integration of donor DNA into recipient DNA are proposed: the synthesis of single-stranded regions in recipient DNA, the interaction of donor DNA with recipient DNA resulting in the production of single-stranded ends on donor DNA, and the stable pairing of homologous single-stranded regions. (auth)

  3. Effects of x-irradiation on a temperate bacteriophage of Haemophilus influenzae. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Boling, M.E.; Randolph, M.L.

    1977-04-01

    The inactivation of bacteriophage HPlcl by x rays in a complex medium was found to be exponential, with a D/sub 0/ (the x-ray exposure necessary to reduce the survival of the phage to 37 percent) of approximately 90 kR. Analysis of results of sucrose sedimentation of DNA from x-irradiated whole phage showed that the D/sub 0/ for intactness of single strands was about 105 kR, and for intactness of double strands, it was much higher. The D/sub 0/ for attachment of x-irradiated phage to the host was roughly estimated as about 1,100 kR. Loss of DNA from the phage occurred and was probably due to lysis of the phage by x irradiation, but the significance of the damage is not clear. The production of single-strand breaks approaches the rate of survival loss after x irradiation. However, single-strand breaks produced by uv irradiation, in the presence of H/sub 2/O/sub 2/, equivalent to 215 kR of x rays, showed no lethal effect on the phage. Although uv-sensitive mutants of the host cell, Haemophilus influenzae, have been shown to reactivate uv-irradiated phage less than does the wild-type host cell, x-irradiated phage survive equally well on the mutants as on the wild type, a fact suggesting that other repair systems are involved in x-ray repair.

  4. Shp2 Deficiency Impairs the Inflammatory Response Against Haemophilus influenzae by Regulating Macrophage Polarization.

    Science.gov (United States)

    Zhao, Lifang; Xia, Jingyan; Li, Tiantian; Zhou, Hui; Ouyang, Wei; Hong, Zhuping; Ke, Yuehai; Qian, Jing; Xu, Feng

    2016-08-15

    Macrophages can polarize and differentiate to regulate initiation, development, and cessation of inflammation during pulmonary infection with nontypeable Haemophilus influenzae (NTHi). However, the underlying molecular mechanisms driving macrophage phenotypic differentiation are largely unclear. Our study investigated the role of Shp2, a Src homology 2 domain-containing phosphatase, in the regulation of pulmonary inflammation and bacterial clearance. Shp2 levels were increased upon NTHi stimulation. Selective inhibition of Shp2 in mice led to an attenuated inflammatory response by skewing macrophages toward alternatively activated macrophage (M2) polarization. Upon pulmonary NTHi infection, Shp2(-/-) mice, in which the gene encoding Shp2 in monocytes/macrophages was deleted, showed an impaired inflammatory response and decreased antibacterial ability, compared with wild-type controls. In vitro data demonstrated that Shp2 regulated activated macrophage (M1) gene expression via activation of p65-nuclear factor-κB signaling, independent of p38 and extracellular regulated kinase-mitogen-activated proteins kinase signaling pathways. Taken together, our study indicates that Shp2 is required to orchestrate macrophage function and regulate host innate immunity against pulmonary bacterial infection.

  5. Cost-benefit analysis of a Haemophilus influenzae type b meningitis prevention programme in The Philippines.

    Science.gov (United States)

    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.

  6. Structural basis for haem piracy from host haemopexin by Haemophilus influenzae.

    Science.gov (United States)

    Zambolin, Silvia; Clantin, Bernard; Chami, Mohamed; Hoos, Sylviane; Haouz, Ahmed; Villeret, Vincent; Delepelaire, Philippe

    2016-05-18

    Haemophilus influenzae is an obligate human commensal/pathogen that requires haem for survival and can acquire it from several host haemoproteins, including haemopexin. The haem transport system from haem-haemopexin consists of HxuC, a haem receptor, and the two-partner-secretion system HxuB/HxuA. HxuA, which is exposed at the cell surface, is strictly required for haem acquisition from haemopexin. HxuA forms complexes with haem-haemopexin, leading to haem release and its capture by HxuC. The key question is how HxuA liberates haem from haemopexin. Here, we solve crystal structures of HxuA alone, and HxuA in complex with the N-terminal domain of haemopexin. A rational basis for the release of haem from haem-haemopexin is derived from both in vivo and in vitro studies. HxuA acts as a wedge that destabilizes the two-domains structure of haemopexin with a mobile loop on HxuA that favours haem ejection by redirecting key residues in the haem-binding pocket of haemopexin.

  7. The HMW1 and HMW2 Adhesins Enhance the Ability of Nontypeable Haemophilus influenzae To Colonize the Upper Respiratory Tract of Rhesus Macaques.

    Science.gov (United States)

    Rempe, Katherine A; Porsch, Eric A; Wilson, Jolaine M; St Geme, Joseph W

    2016-10-01

    Nontypeable Haemophilus influenzae (NTHi) initiates infection by colonizing the upper respiratory tract and is a common cause of localized respiratory tract disease. Previous work has established that the NTHi HMW1 and HMW2 proteins are potent adhesins that mediate efficient in vitro adherence to cultured human respiratory epithelial cells. In this study, we used a rhesus macaque model to assess the contributions of HMW1 and HMW2 to in vivo colonization. In experiments involving inoculation of individual isogenic derivatives of NTHi strain 12, the parent strain expressing both HMW1 and HMW2 and the mutant strains expressing either HMW1 or HMW2 were able to colonize more frequently than the double mutant strain lacking HMW1 and HMW2. In competition experiments, the parent strain efficiently outcompeted the double mutant lacking HMW1 and HMW2. Colonization with strains expressing HMW2 resulted in development of antibody against HMW2 in a number of the animals, demonstrating that colonization can stimulate an antibody response. In conclusion, we have established that the HMW1 and HMW2 adhesins play a major role in facilitating colonization of the upper respiratory tract of rhesus macaques, in some cases associated with stimulation of an immune response.

  8. Antimicrobial susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis isolated from community-acquired respiratory tract infections in China: Results from the CARTIPS Antimicrobial Surveillance Program.

    Science.gov (United States)

    Zhang, Yawei; Zhang, Feifei; Wang, Hui; Zhao, Chunjiang; Wang, Zhanwei; Cao, Bin; Du, Yan; Feng, Xianju; Hu, Yunjian; Hu, Bijie; Ji, Ping; Liu, Zhiyong; Liu, Yong; Liao, Wanzhen; Lu, Juan; Sun, Hongli; Wang, Zhongxin; Xu, Xiuli; Xu, Xuesong; Yang, Qing; Yu, Yunsong; Zhang, Rong; Zhuo, Chao

    2016-06-01

    This study investigated the antimicrobial susceptibilities of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis isolates causing adult community-acquired respiratory tract infections (CARTIs) in China. A multicentre resistance surveillance study (CARTIPS) investigating 1046 clinical isolates from 19 hospitals in China was conducted from 2013 to 2014. Based on the minimum inhibitory concentration (MIC) breakpoints of oral penicillin, the percentages of penicillin-resistant, penicillin-intermediate and penicillin-susceptible S. pneumoniae were 44.1%, 13.7%, and 42.2%, respectively. The rates of penicillin-non-susceptible S. pneumoniae ranged from 27.9% to 72.2% in different cities, with the highest rate in Nanchang. Macrolides, including azithromycin, clarithromycin and erythromycin, showed the lowest activities against S. pneumoniae isolates, with resistance rates of 90.5%, 92.2% and 93.0%, respectively. However, 98% of these strains were susceptible to levofloxacin and moxifloxacin. For H. influenzae isolates, most of the antimicrobials agents exhibited good activities. However, ampicillin and trimethoprim/sulfamethoxazole showed relatively lower activity against H. influenzae, with resistance rates of 35.0% and 54.4%, respectively. β-lactamase production rates amongst H. influenzae and M. catarrhalis were 31.0% and 87.1%, respectively. In addition, a total of 15 β-lactamase-negative ampicillin-resistant (BLNAR) strains identified in this study were resistant to ampicillin, amoxicillin/clavulanic acid, cefaclor and cefuroxime. Most of the antimicrobial agents showed excellent activity against M. catarrhalis, with susceptibility rates of >90%. The results from the current study confirmed the regional variations in antimicrobial susceptibility of major CARTI pathogens and provided some choices for the treatment of these organisms. Continuous national surveillance of the epidemiology of CARTIs is strongly warranted in China.

  9. Nationwide survey of the development of drug resistance in the pediatric field in 2007 and 2010: drug sensitivity of Haemophilus influenzae in Japan (second report).

    Science.gov (United States)

    Hoshino, Tadashi; Sato, Yoshitake; Toyonaga, Yoshikiyo; Hanaki, Hideaki; Sunakawa, Keisuke

    2013-06-01

    The Drug-Resistant Pathogen Surveillance Group in Pediatric Infectious Disease conducted national surveillance for Haemophilus influenzae in 2007 (phase 3) and 2010 (phase 4), following the previous surveillance conducted from 2000 to 2001 (phase 1) and in 2004 (phase 2). We examined the antimicrobial susceptibility for H. influenzae derived from clinical specimens of pediatric patients collected nationwide from 27 institutions during phases 3 (386 strains) and 4 (484 strains). The frequency of β-lactamase-nonproducing ampicillin (ABPC)-resistant (BLNAR) strains, which rapidly increased from 11.4 % in phase 1 to 43.4 % in phase 2, has gradually decreased from 38.3 % in phase 3 to 37.8 % in phase 4. In contrast, On the other hand, the frequency of β-lactamase-producing strains, which continuously decreased from 8.3 % in phase 1 to 4.4 % in phase 3, has increased to 8.7 % in phase 4. Prevalence of β-lactamase-producing clavulanic acid/amoxicillin-resistant (BLPACR) strains, especially, has increased from 1.6 % in phase 3 to 4.8 % in phase 4. The oral antimicrobial agents with the lowest MIC90 were levofloxacin in both phases, and tosufloxacin in phase 4 (≤0.063 μg/ml), whereas for intravenous use the corresponding agent was tazobactam/piperacillin in both phases (0.125 μg/ml). There was no increase in the MIC90 of most β-lactams between phase 3 and phase 4. In relationship to sex, age, presence of siblings, attendance at a daycare center, siblings' attendance at a daycare center, and prior administration of antimicrobial agents within 1 month, the frequency of β-lactamase-nonproducing ABPC-intermediately resistant (BLNAI) strains + BLNAR strains was high (P = 0.005) in cases with prior administration of antimicrobial agents in phase 3.

  10. Haemophilus influenzae responds to glucocorticoids used in asthma therapy by modulation of biofilm formation and antibiotic resistance.

    Science.gov (United States)

    Earl, Chris S; Keong, Teh Wooi; An, Shi-qi; Murdoch, Sarah; McCarthy, Yvonne; Garmendia, Junkal; Ward, Joseph; Dow, J Maxwell; Yang, Liang; O'Toole, George A; Ryan, Robert P

    2015-08-01

    Glucocorticosteroids are used as a main treatment to reduce airway inflammation in people with asthma who suffer from neutrophilic airway inflammation, a condition frequently associated with Haemophilus influenzae colonization. Here we show that glucocorticosteroids have a direct influence on the behavior of H. influenzae that may account for associated difficulties with therapy. Using a mouse model of infection, we show that corticosteroid treatment promotes H. influenzae persistence. Transcriptomic analysis of bacteria either isolated from infected mouse airway or grown in laboratory medium identified a number of genes encoding regulatory factors whose expression responded to the presence of glucocorticosteroids. Importantly, a number of these corticosteroid-responsive genes also showed elevated expression in H. influenzae within sputum from asthma patients undergoing steroid treatment. Addition of corticosteroid to H. influenzae led to alteration in biofilm formation and enhanced resistance to azithromycin, and promoted azithromycin resistance in an animal model of respiratory infection. Taken together, these data strongly suggest that H. influenzae can respond directly to corticosteroid treatment in the airway potentially influencing biofilm formation, persistence and the efficacy of antibiotic treatment.

  11. Haemophilus influenzae responds to glucocorticoids used in asthma therapy by modulation of biofilm formation and antibiotic resistance

    Science.gov (United States)

    Earl, Chris S; Keong, Teh Wooi; An, Shi-qi; Murdoch, Sarah; McCarthy, Yvonne; Garmendia, Junkal; Ward, Joseph; Dow, J Maxwell; Yang, Liang; O’Toole, George A; Ryan, Robert P

    2015-01-01

    Glucocorticosteroids are used as a main treatment to reduce airway inflammation in people with asthma who suffer from neutrophilic airway inflammation, a condition frequently associated with Haemophilus influenzae colonization. Here we show that glucocorticosteroids have a direct influence on the behavior of H. influenzae that may account for associated difficulties with therapy. Using a mouse model of infection, we show that corticosteroid treatment promotes H. influenzae persistence. Transcriptomic analysis of bacteria either isolated from infected mouse airway or grown in laboratory medium identified a number of genes encoding regulatory factors whose expression responded to the presence of glucocorticosteroids. Importantly, a number of these corticosteroid-responsive genes also showed elevated expression in H. influenzae within sputum from asthma patients undergoing steroid treatment. Addition of corticosteroid to H. influenzae led to alteration in biofilm formation and enhanced resistance to azithromycin, and promoted azithromycin resistance in an animal model of respiratory infection. Taken together, these data strongly suggest that H. influenzae can respond directly to corticosteroid treatment in the airway potentially influencing biofilm formation, persistence and the efficacy of antibiotic treatment. PMID:25995336

  12. Evaluation of Haemophilus influenzae type b carrier status among children 10 years after the introduction of Hib vaccine in Brazil

    Science.gov (United States)

    Zanella, Rosemeire Cobo; Brandileone, Maria Cristina de Cunto; Andrade, Ana Lúcia; Ogassavara, Cinthya Terumi; Fiório, Cleiton Eduardo; Brandão, Angela Pires; Almeida, Samanta Cristine Grassi; Lemos, Ana Paula Silva; Gorla, Maria Cecília; Carvalhanas, Telma Regina; Sato, Helena; Liphaus, Bernadete; Nerger, Maria Lígia; Conde, Monica; Ribeiro, Ana Freitas

    2015-01-01

    The aim of the present study was to assess the prevalence of Haemophilus influenzae type b (Hib) nasopharyngeal (NP) colonisation among healthy children where Hib vaccination using a 3p+0 dosing schedule has been routinely administered for 10 years with sustained coverage (> 90%). NP swabs were collected from 2,558 children who had received the Hib vaccine, of whom 1,379 were 12-< 24 months (m) old and 1,179 were 48-< 60 m old. Hi strains were identified by molecular methods. Hi carriage prevalence was 45.1% (1,153/2,558) and the prevalence in the 12-< 24 m and 48-< 60 m age groups were 37.5% (517/1,379) and 53.9% (636/1,179), respectively. Hib was identified in 0.6% (16/2,558) of all children in the study, being 0.8% (11/1,379) and 0.4% (5/1,179) among the 12-< 24 m and 48-< 60 m age groups, respectively. The nonencapsulate Hi colonisation was 43% (n = 1,099) and was significantly more frequent at 48-< 60 m of age (51.6%, n = 608) compared with that at 12-< 24 m of age (35.6%, n = 491). The overall resistance rates to ampicillin and chloramphenicol were 16.5% and 3.7%, respectively; the co-resistance was detected in 2.6%. Our findings showed that the Hib carrier rate in healthy children under five years was very low after 10 years of the introduction of the Hib vaccine. PMID:26517654

  13. Molecular cloning and characterization of the nontypeable Haemophilus influenzae 2019 rfaE gene required for lipopolysaccharide biosynthesis.

    Science.gov (United States)

    Lee, N G; Sunshine, M G; Apicella, M A

    1995-03-01

    The lipooligosaccharide (LOS) of nontypeable Haemophilus influenzae (NTHi) is an important factor in pathogenesis and virulence. In an attempt to elucidate the genes involved in LOS biosynthesis, we have cloned the rfaE gene from NTHi 2019 by complementing a Salmonella typhimurium rfaE mutant strain with an NTHi 2019 plasmid library. The rfaE mutant synthesizes lipopolysaccharide (LPS) lacking heptose, and the rfaE gene is postulated to be involved in ADP-heptose synthesis. Retransformation with the plasmid containing 4 kb of NTHi DNA isolated from a reconstituted mutant into rfaE mutants gave wild-type LPS phenotypes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis confirmed the conversion of the rfaE mutant LPS to a wild-type LPS phenotype. Sequence analysis of a 2.4-kb BglII fragment revealed two open reading frames. One open reading frame encodes the RfaE protein with a molecular weight of 37.6 kDa, which was confirmed by in vitro transcription and translation, and the other encodes a polypeptide highly homologous to the Escherichia coli HtrB protein. These two genes are transcribed from the same promoter region into opposite directions. Primer extension analysis of the rfaE gene revealed a single transcription start site at 37 bp upstream of the predicted translation start site. The upstream promoter region contained a sequence (TA AAAT) homologous to the -10 region of the bacterial sigma 70-dependent promoters at an appropriate distance (7 bp), but not sequence resembling the consensus sequence of the -35 region was found. These studies demonstrate the ability to use complementation of defined LPS defects in members of the family Enterobacteriaceae to identify LOS synthesis genes in NTHi.

  14. Dps promotes survival of nontypeable Haemophilus influenzae in biofilm communities in vitro and resistance to clearance in vivo

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    Bing ePang

    2012-05-01

    Full Text Available Nontypeable Haemophilus influenzae (NTHi is a common airway commensal and opportunistic pathogen that persists within surface-attached biofilm communities. In this study, we tested the hypothesis that bacterial stress-responses are activated within biofilms. Transcripts for several factors associated with bacterial resistance to environmental stress were increased in biofilm cultures as compared to planktonic cultures. Among these, a homolog of the DNA-binding protein from starved cells (dps was chosen for further study. An isogenic NTHi 86-028NP dps mutant was generated and tested for resistance to environmental stress, revealing a significant survival defects in high-iron conditions, which was mediated by oxidative stress and was restored by genetic complementation. As expected, NTHi 86-028NP dps had a general stress-response defect, exhibiting decreased resistance to many types of environmental stress. While no differences were observed in density and structure of NTHi 86-028NP and NTHi 86-028NP dps biofilms, bacterial survival was decreased in NTHi 86-028NP dps biofilms as compared to the parental strain. The role of dps persistence in vivo was tested in animal infection studies. NTHi 86-028NP dps had decreased resistance to clearance after pulmonary infection of elastase-treated mice as compared to NTHi 86-028NP, whereas minimal differences were observed in clearance from mock-treated mice. Similarly, lower numbers of NTHi 86-028NP dps were recovered from middle-ear effusions and bullar homogenates in the chinchilla model for otitis media. Therefore, we conclude that Dps promotes bacterial survival within NTHi biofilm communities both in vitro and in chronic infections in vivo.

  15. Resistance mechanism of Haemophilus influenzae against β- lactam antibiotics and fluoroquinolone%流感嗜血杆菌对β内酰胺类和氟喹诺酮类药物的耐药机制

    Institute of Scientific and Technical Information of China (English)

    马池; 吕媛

    2012-01-01

    Objective To investigate the susceptibility of Haemophilus influenzae to p - lactam antimicrobial agents and fluoroquinolones and to explore the resistance mechanism. Methods Minimal inhibitory concentrations ( MIC)of clinical isolate Haemophilus influenzaes against p - lactam antimicrobial agents and fluoroquinolones were evaluated by the serial two - fold agar dilution method. The production or presence of P - lacta-mase was studied by the rapid method utilizing ihe chromogenic cephalo-sporin compound nitrocefin in cultures of Haemophilus influenzaes. Then TEM -1 and ROB - 1 type of p - lactamase genes and quinolones - resistant determining regions ( QRDR) of fluoroquinolone resistant strain were detected by polymerase chain reaction ( PCR) amplification and product sequencing. Results The susceptible rate of the 183 strains Haemophilus influenzae to ampicillin was 73.2% . Otherwise, all the strains were all susceptible to ampicillin - sulbactam, cefotaxime and cefepim. Two ciprofloxacin and 3 moxifloxacin resistance strains were detected, and one of them was not susceptible to both ciprofloxacin and moxifloxacin. Of the 183 strains Haemophilus influenzae, 34 isolates (18. 6% ) were determinated as p - lactamase producing strains. One hundred percent of the p - lactainase positive strains gave a positive result with specific primers for the TEM - 1 gene. None strain was detected for the ROB -1 gene with in 34 strains in all the 183 strains. One or more mutations in GyrA and ParC in QRDR were detected in all the fluoroquinolone resistance Haemophilus influenzaes, even the change of ami-no acids in position 84 or (and) 88 of GyrA occurred more frequently. Conclusion Other than ampicillin, cephalospo-rins and fluoroquinolones show potent activities against Haemophilus influenzae. The major mechanism of Haemophilus influenzae resistance to p - lactam antibiotics is mainly the presence of β - lactamase, mainly TEM - 1 type enzyme. ROB -1 gene should be persistently

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

    Directory of Open Access Journals (Sweden)

    N Mojgani

    2013-01-01

    Full Text Available Purpose: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. Materials and Methods: 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 (LD 50 were recorded in different challenge groups. Results: 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 LD 50 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 (10 8 cfu and in the presence of VEA. Conclusions: 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.

  17. 临床分离流感嗜血杆菌和副流感嗜血杆菌的耐药性研究%Resistance profiles of Haemophilus influenzae and Haemophilus parainfluenzae isolates in Shanghai

    Institute of Scientific and Technical Information of China (English)

    袁瑾懿; 杨帆; 徐晓刚; 叶信予; 胡付品; 朱德妹

    2009-01-01

    Objective. To understand drug susceptibilities to common antibacterials, resistance mechanism to β-lactams and quinolones and the clonal spread of resistant stains of Haemophilus influenzae (H. influenzae) and Haernophilus parainfluenzae (H. parainfluenzae) isolated from some hospitals in Shanghai. Methods The in vitro antimicrobial susceptibilities to 13 antibacterials, such as ampicillin, of 156 Haemophilus strains collected from 5 hospitals of Shanghai in 2006 were tested by agar dilution method. The β-lactamase production was determined by chromogenic cephalosporin test. TEM and ROB type of β-lactamase genes and quinolone resistance determining regions (QRDR) of ciprofloxacin-resistant strains were detected by polymerase chain reaction (PCR) amplification. The homology of H. influenzae strains were analyzed by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Results The susceptible rate of 109 strains H. influenzae to ampicillin was 74.3%, while those to ampicillin-sulbactam, cephatosporins and fluoroquinolones were all 100.0%. The β-lactamases-producing rates of 109 strains H. influenzae and 47 strains H. parainfluenzae were 25.7% and 19.1% (χ2=0.776,P=0.378), respectively. TEM gene was detected in all β-lactamases-producing strains. Of 109 H. influenzae isolates, only one was resistant to ciprofloxacin, and Ser84Leu mutation was detected in gyrA gene and Gly206Arg mutation in parC gene. The results of ERIC-PCR showed that 106 H. influenzae strains were clustered into 73 groups with similarity level of 85%. Conclusions Clinical isolates of H. influenzae from hospitals in Shanghai remain highly susceptible to common antimicrobial agents except ampicillin. TEM type of β-lactamase production is the main ampicillin-resistant mechanism of the tested stains. The clonal spread of H. influenzae, including ampicillin-resistant strains, is not prevalent.%目的 了解上海部分医院分离的流感和副流感嗜血杆菌对常用抗菌药物的敏

  18. Tests for the mutagenic action of a number of chemicals on Haemophilus influenzae with special emphasis on hydrazine

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, R.F.; Hirsch, B.F.

    1975-01-01

    A number of chemicals have been tested for their ability to produce novobiocin-resistant mutants in Haemophilus influenzae. Of these, hydrazine (HZ) proved unique because it induced a fairly high incidence of mutation without killing significant numbers of cells at concentrations ranging over nearly four orders of magnitude. Moreover, its dose--effect curve increased very slowly initially and reached a relatively low maximum. It is suggested that HZ may be acting as both a mutagen and an antimutagen in this system. (auth)

  19. Meningitis Due to Ampicillin-and Chloramphenicol-Resistant Haemophilus influenzae Type B in Canada. Case Report and Review

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    Amin Kabani

    1990-01-01

    Full Text Available 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.

  20. Repair and actio spectrum of oxygen-independent lethality of near uv light on Haemophilus influenzae and lack of mutation

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Juarez, E.; Setlow, J.K.

    1980-01-01

    Haemophilus influenzae has been inactivated anaerobically at 313, 334, 365, and 405 nm, and exhibits the greatest sensitivity at 334 nm. The rec1 and uvr1 mutants show the greatest increase in sensitivity over the wild-type at 313 nm, but differences could be seen also at the other wavelengths. Anaerobic irradiation is less effective for killing at all the wavelengths than irradiation under aerobic conditions, but the greatest difference was observed at 365 nm. No induced mutation was seen as a result of anaerobic irradiation at 334 nm, although purified transforming DNA can be mutated at this wavelength.

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

    Science.gov (United States)

    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.

  2. Vigilancia de los serotipos y susceptibilidad antimicrobiana de Haemophilus influenzae en Colombia, 1994-2002.

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    María Victoria Ovalle

    2003-06-01

    Full Text Available La enfermedad invasora causada por Haemophilus influenzae, serotipo b, ha sido una de las mayores causas de morbilidad y mortalidad en la población infantil; afortunadamente, en algunos países con amplia cobertura de la vacuna conjugada esta situación ha cambiado. En 1994 se inició en el Grupo de Microbiología un programa de vigilancia de la susceptibilidad antimicrobiana y de los serotipos de aislamientos invasores de H. influenzae, remitidos por los hospitales y Laboratorios de Salud Pública del país como componente de los programas de vigilancia en red de infección respiratoria aguda y meningitis bacteriana aguda. El objetivo de este trabajo fue determinar la evolución de los serotipos y los patrones de susceptibilidad antimicrobiana de los aislamientos invasores de H. influenzae obtenidos de 1994 al 2002 y realizar un nuevo análisis sobre el impacto de la vacuna conjugada de H. influenzae, serotipo b, en Colombia. De 1994 a 2002 se han estudiado 683 aislamientos; 379 (55,5% de pacientes del género masculino; 370 (54,2% de menores de 1 año; 227 (33,2% de 1 a 5 años; 19 (2,8% de 6 a 14 años; 38 (5,6% de mayores de 14 años, y de 29 (4,2% no se tenía el dato de la edad; 493 (72,2% fueron recuperados de pacientes con meningitis, 181 (26,5% de neumonía y 9 (0,9% de otras enfermedades. El 85,1% de los aislamientos fueron H. influenzae, serotipo b, 12,9% no capsulares y 2,0% de otros serotipos (10 a, 1 d, 1 e y 2 f. Del total de aislamientos, 12% fueron productores de beta-lactamasa; 13,9%, resistentes a ampicilina; 12,7%, a trimetoprim sulfametoxazol (SXT; 5,4%, a cloranfenicol, y 1% a cefuroxima; todos fueron sensibles a ceftriaxona. Durante este período se observó un incremento en la resistencia de los aislamientos a SXT (5% al 13%, pero la diferencia no fue estadísticamente significativa (p=0,1. Con la vigilancia se pudo determinar una disminución significativa de los casos de meningitis en los menores de 1 año y en el

  3. Haemophilus influenzae pneumonia in human immunodeficiency virus-infected patients. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

    Science.gov (United States)

    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.

  4. Impacto da vacinação contra o Haemophilus influenzae b na redução de meningites, Goiás

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    Simões Luciana Leite Pineli

    2004-01-01

    Full Text Available OBJETIVO: Avaliar o impacto da vacinação contra o Haemophilus influenzae b na incidência de meningites em crianças menores de cinco anos de idade. MÉTODOS: Utilizou-se o delineamento tipo "antes-depois" para comparar as taxas de incidência de meningites por Haemophilus influenzae b nos períodos pré-vacinação (julho/95-junho/99 e pós-vacinação (julho/99-junho/2001 no Estado de Goiás. A definição de caso de meningite bacteriana seguiu os critérios da Organização Mundial de Saúde. As taxas de meningite por Streptococcus pneumoniae e Neisseria. meningitidis foram utilizadas para efeito de comparação. Para análise estatística foram utilizados o teste de chi2 e o t de Student. Valores de p<0,05 foram considerados estatisticamente significantes. RESULTADOS: Foi detectada meningite bacteriana aguda em 979 crianças no período de estudo. A incidência de meningite por Haemophilus influenzae b diminuiu de 10,8x10(5 no período pré-vacinal para 2,3x10(5 no segundo ano pós-vacina, significando 78% de redução no risco, principalmente na faixa etária de 7-23 meses (p<0,05. Foram prevenidos 65 casos de meningite por Haemophilus influenzae b. Observou-se aumento na incidência de meningite por S. pneumoniae. Foi observada falha vacinal em um caso. CONCLUSÕES: Expressivo declínio da incidência de meningite por Haemophilus influenzae b foi detectado, precocemente, logo após o primeiro ano de introdução da vacina contra o Haemophilus influenzae b. Assim, se faz necessária a vigilância contínua com instrumental de alta acurácia para: (i detectar re-emergência do Haemophilus influenzae b; (ii avaliar possibilidade de falha vacinal; (iii identificar mudanças no padrão dos sorotipos do H. influenzae.

  5. Acute Exacerbations in COPD and their Control with Oral Immunisation with nontypeable Haemophilus influenzae

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    Robert eClancy

    2011-03-01

    Full Text Available Chronic obstructive pulmonary disease (COPD a term based on the demonstration of irreversible airways obstruction, introduced to unify a range of chronic progressive diseases of the airways consequent upon inhalation of toxins. While disease is initiated and progressed by inhaled toxins, an additional pathway of damage has emerged, with particular relevance to acute exacerbations. Exacerbations of disease due to an increase in the level of intra-bronchial inflammation have taken on a new significance as their role in determining both acute and chronic outcomes is better understood. This ‘second pathway’ of disease is a consequence of bacterial colonisation of damaged airways. Although bacteria have been linked to acute episodes in COPD over 50 years, only recently has quality data on antibiotic usage and the detection of ‘exacerbation isolates’ of non-typeable Haemophilus influenzae (NTHi provided strong argument in support of a pathogenic role. Yet a poor correlation between detection of colonising bacteria and clinical status remained a concern in attempts to explain a role for bacteria in a classical infection model. This presentation discusses a hypothesis that acute exacerbations reflect a T-cell dependent hypersensitivity response to colonising bacteria, with IL-17 dependent accumulation of neutrophils within the bronchus, as the main outcome measure. Critical protection against exacerbations following oral administration of NTHi, an immunotherapy that drives a TH17 Tcell response from Peyer’s patches, reduces the load of intrabronchial bacteria while preventing access of inhaled bacteria into small airways. Immunotherapy augments a physiological ‘loop’ based on aspiration of bronchus content into the gut. A second ‘hypersensitivity’ mechanism may cause bronchospasm – in both COPD and treatment-resistant asthma – due to specific IgE antibody directed against colonising bacteria, as oral NTHi abrogates wheeze in

  6. No evidence of increasing Haemophilus influenzae non-b infection in Australian Aboriginal children

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    Robert I. Menzies

    2013-08-01

    Full Text Available Background. High, or increasing, rates of invasive Haemophilus influenzae (Hi type a disease have been reported from North American native children from circumpolar regions, raising the question of serotype replacement being driven by vaccination against Hi type b (Hib. Indigenous Australians from remote areas had high rates of invasive Hib disease in the past, comparable to those in North American Indigenous populations. Objective. Evaluate incidence rates of invasive Hi (overall and by serotype in Indigenous Australian children over time. Design. Descriptive study of Hi incidence rates by serotype, in the Northern Territory (NT and South Australia (SA from 2001 to 2011. Comparison of NT data with a study that was conducted in the NT in 1985–1988, before Hib vaccine was introduced. Results. The average annual rate of invasive Hi type a (Hia disease in Indigenous children aged <5 years was 11/100,000 population. Although the incidence of Hi infection in Indigenous children in 2001–2003 was lower than during 2004–2011, this may be due to changes in surveillance. No other trend over time in individual serotypes or total invasive Hi disease, in Indigenous or non-Indigenous people, was identified. Compared to 1985–1988, rates in 2001–2011 were lower in all serotype groupings, by 98% for Hib, 75% for Hia, 79% for other serotypes and 67% for non-typeable Hi. Conclusions. There is no evidence of increases in invasive disease due to Hia, other specific non-b types, or non-typeable Hi in Australian Indigenous children. These data suggest that the increase in Hia some time after the introduction of Hib vaccine, as seen in the North American Arctic Region, is not common to all populations with high pre-vaccine rates of invasive Hib disease. However, small case numbers and the lack of molecular subtyping and PCR confirmation of pre-vaccine results complicate comparisons with North American epidemiology.

  7. Economic evaluations of Haemophilus influenzae type b (Hib) vaccine: a systematic review.

    Science.gov (United States)

    Chongmelaxme, Bunchai; Hammanee, Maythika; Phooaphirak, Wariya; Kotirum, Surachai; Hutubessy, Raymond; Chaiyakunapruk, Nathorn

    2017-10-01

    The World Health Organization (WHO) recommends the use of Haemophilus influenzae type b (Hib) conjugate vaccines, but China and Thailand have not used Hib vaccination in their national immunization programs. This systematic review aimed to update published economic evaluations of Hib vaccinations and to determine factors that potentially affected their cost-effectiveness. Searches were performed from the inception until December 2015 using 13 databases: CAB direct; CEA registry; EconLit; EMBASE; E-library; NHSEED; PAHO; POPLINE; PubMed; Redalyc project; RePEc; SciELO; and WHOLIS. Reference lists of relevant studies and grey literature were also searched. Full economic evaluations of Hib vaccination with results of costs and outcomes were included. The WHO checklist was used to evaluate the quality of the included studies. Data from eligible studies were extracted using a standardized data collection form. Out of 830 articles, 27 were included. Almost half of the studies (12/27) were conducted in high-income countries. Twelve studies (12/27) investigated the Hib vaccine as an addition to the existing vaccination program. Most studies (17/27) examined a 3-dose schedule of Hib vaccine. Nineteen studies (19/27) reported the model used, where all were decision tree models. Most of the studies (23/27) demonstrated an economic value of Hib vaccination programs, key influential parameters being incidence rates of Hib disease and vaccine price. Hib vaccination programs are mostly found to be cost-effective across geographic regions and country income levels, and Hib vaccination is recommended for inclusion into all national immunization programs. The findings are expected to support policy-makers for making decisions on allocating limited resources of the Hib vaccination program effectively.

  8. Recognition of Nucleoside Monophosphate Substrates by Haemophilus influenzae Class C Acid Phosphatase

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Harkewal; Schuermann, Jonathan P.; Reilly, Thomas J.; Calcutt, Michael J.; Tanner, John J. (Cornell); (UMC)

    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 pockets 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.

  9. Transformed Recombinant Enrichment Profiling Rapidly Identifies HMW1 as an Intracellular Invasion Locus in Haemophilus influenza

    Science.gov (United States)

    Moleres, Javier; Sinha, Sunita; Fernández-Calvet, Ariadna; Porsch, Eric A.; St. Geme, Joseph W.; Nislow, Corey; Redfield, Rosemary J.; Garmendia, Junkal

    2016-01-01

    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. PMID:27124727

  10. Preclinical evaluation of a Haemophilus influenzae type b conjugate vaccine process intended for technology transfer.

    Science.gov (United States)

    Hamidi, Ahd; Verdijk, Pauline; Kreeftenberg, Hans

    2014-01-01

    Introduction of Haemophilus influenzae type b (Hib) vaccine in low- and middle-income countries has been limited by cost and availability of Hib conjugate vaccines for a long time. It was previously recognized by the Institute for Translational Vaccinology (Intravacc, originating from the former Vaccinology Unit of the National Institute of Public Health [RIVM] and the Netherlands Vaccine Institute [NVI]) that local production of a Hib conjugate vaccine would increase the affordability and sustainability of the vaccine and thereby help to speed up Hib introduction in these countries. A new affordable and a non-infringing production process for a Hib conjugate vaccine was developed, including relevant quality control tests, and the technology was transferred to a number of vaccine manufacturers in India, Indonesia, and China. As part of the Hib technology transfer project managed by Intravacc, a preclinical toxicity study was conducted in the Netherlands to test the safety and immunogenicity of this new Hib conjugate vaccine. The data generated by this study were used by the technology transfer partners to accelerate the clinical development of the new Hib conjugate vaccine. A repeated dose toxicity and local tolerance study in rats was performed to assess the reactogenicity and immunogenicity of a new Hib conjugate vaccine compared to a licensed vaccine. The results showed that the vaccine was well tolerated and immunogenic in rats, no major differences in both safety and immunogenicity in rats were found between the vaccine produced according to the production process developed by Intravacc and the licensed one. Rats may be useful to verify the immunogenicity of Hib conjugate vaccines and for preclinical evaluation. In general, nonclinical evaluation of the new Hib conjugate vaccine, including this proof of concept (safety and immunogenicity study in rats), made it possible for technology transfer partners, having implemented the original process with no changes

  11. Resolvin D1 Dampens Pulmonary Inflammation and Promotes Clearance of Nontypeable Haemophilus influenzae.

    Science.gov (United States)

    Croasdell, Amanda; Lacy, Shannon H; Thatcher, Thomas H; Sime, Patricia J; Phipps, Richard P

    2016-03-15

    Nontypeable Haemophilus influenzae (NTHi) is a Gram-negative, opportunistic pathogen that frequently causes ear infections, bronchitis, pneumonia, and exacerbations in patients with underlying inflammatory diseases, such as chronic obstructive pulmonary disease. In mice, NTHi is rapidly cleared, but a strong inflammatory response persists, underscoring the concept that NTHi induces dysregulation of normal inflammatory responses and causes a failure to resolve. Lipid-derived specialized proresolving mediators (SPMs) play a critical role in the active resolution of inflammation by both suppressing proinflammatory actions and promoting resolution pathways. Importantly, SPMs lack the immunosuppressive properties of classical anti-inflammatory therapies. On the basis of these characteristics, we hypothesized that aspirin-triggered resolvin D1 (AT-RvD1) would dampen NTHi-induced inflammation while still enhancing bacterial clearance. C57BL/6 mice were treated with AT-RvD1 and infected with live NTHi. AT-RvD1-treated mice had lower total cell counts and neutrophils in bronchoalveolar lavage fluid, and had earlier influx of macrophages. In addition, AT-RvD1-treated mice showed changes in temporal regulation of inflammatory cytokines and enzymes, with decreased KC at 6 h and decreased IL-6, TNF-α, and cyclooxygenase-2 expression at 24 h post infection. Despite reduced inflammation, AT-RvD1-treated mice had reduced NTHi bacterial load, mediated by enhanced clearance by macrophages and a skewing toward an M2 phenotype. Finally, AT-RvD1 protected NTHi-infected mice from weight loss, hypothermia, hypoxemia, and respiratory compromise. This research highlights the beneficial role of SPMs in pulmonary bacterial infections and provides the groundwork for further investigation into SPMs as alternatives to immunosuppressive therapies like steroids.

  12. Early-Life Intranasal Colonization with Nontypeable Haemophilus influenzae Exacerbates Juvenile Airway Disease in Mice.

    Science.gov (United States)

    McCann, Jessica R; Mason, Stanley N; Auten, Richard L; St Geme, Joseph W; Seed, Patrick C

    2016-07-01

    Accumulating evidence suggests a connection between asthma development and colonization with nontypeable Haemophilus influenzae (NTHi). Specifically, nasopharyngeal colonization of human infants with NTHi within 4 weeks of birth is associated with an increased risk of asthma development later in childhood. Monocytes derived from these infants have aberrant inflammatory responses to common upper respiratory bacterial antigens compared to those of cells derived from infants who were not colonized and do not go on to develop asthma symptoms in childhood. In this study, we hypothesized that early-life colonization with NTHi promotes immune system reprogramming and the development of atypical inflammatory responses. To address this hypothesis in a highly controlled model, we tested whether colonization of mice with NTHi on day of life 3 induced or exacerbated juvenile airway disease using an ovalbumin (OVA) allergy model of asthma. We found that animals that were colonized on day of life 3 and subjected to induction of allergy had exacerbated airway disease as juveniles, in which exacerbated airway disease was defined as increased cellular infiltration into the lung, increased amounts of inflammatory cytokines interleukin-5 (IL-5) and IL-13 in lung lavage fluid, decreased regulatory T cell-associated FOXP3 gene expression, and increased mucus production. We also found that colonization with NTHi amplified airway resistance in response to increasing doses of a bronchoconstrictor following OVA immunization and challenge. Together, the murine model provides evidence for early-life immune programming that precedes the development of juvenile airway disease and corroborates observations that have been made in human children.

  13. Accelerating policy decisions to adopt haemophilus influenzae type B vaccine: a global, multivariable analysis.

    Directory of Open Access Journals (Sweden)

    Jessica C Shearer

    2010-03-01

    Full Text Available BACKGROUND: 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. METHODS AND FINDINGS: 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. CONCLUSIONS: 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.

  14. Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

    Science.gov (United States)

    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.

  15. An unusual case of chronic prostatitis caused by Haemophilus influenzae in an elderly Saudi patient: A case report and literature review

    Science.gov (United States)

    Al-Mohizea, Maha M.; Alotaibi, Fawzia E.

    2014-01-01

    Haemophilus influenzae has been reported on rare occasions as the cause of prostatitis and urinary tract infections. Here, we report a rare case of chronic prostatitis in a 52-year-old male with benign prostatic hypertrophy and discuss the possible underestimation of the true incidence of H. influenzae in genitourinary infections. This organism was identified only by its growth on chocolate agar, a medium that is not commonly used for urine cultures. PMID:25374472

  16. An unusual case of chronic prostatitis caused by Haemophilus influenzae in an elderly Saudi patient: A case report and literature review

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    Maha M Al-Mohizea

    2014-01-01

    Full Text Available Haemophilus influenzae has been reported on rare occasions as the cause of prostatitis and urinary tract infections. Here, we report a rare case of chronic prostatitis in a 52-year-old male with benign prostatic hypertrophy and discuss the possible underestimation of the true incidence of H. influenzae in genitourinary infections. This organism was identified only by its growth on chocolate agar, a medium that is not commonly used for urine cultures.

  17. Necrotizing fasciitis of lower extremity caused by Haemophilus influenzae in a healthy adult with a closed lisfranc injury.

    Science.gov (United States)

    Gonzalez, R Wesley; Casillas, Mark M; Almaguer, Enrique C

    2014-05-01

    Necrotizing fasciitis is a rare bacterial infection with an incidence of approximately 0.4 cases per 100,000 population. Although the majority of cases of necrotizing fasciitis are polymicrobial, a systematic review of the literature found only 7 reports of Haemophilus influenzae as the causal agent, and only 1 incidence of H influenzae causing the infection in a healthy adult. This report documents the unusual case of necrotizing fasciitis in a healthy adult with a history of smoking as her only risk factor. The patient presented with a seemingly innocuous low-grade Lisfranc injury. Our case illustrates the importance of early diagnosis and aggressive surgical management and medical treatment of necrotizing fasciitis.

  18. Remarkably high prevalence of fts I gene mutations in Haemophilus influenzae isolates from upper respiratory tract infections in children of the Sapporo district, Japan.

    Science.gov (United States)

    Harimaya, Atsushi; Yokota, Shin-ichi; Sato, Kiyoshi; Himi, Tetsuo; Fujii, Nobuhiro

    2008-06-01

    Recently, the frequency of isolation of beta-lactamase-negative ampicillin resistant (BLNAR) strains of Haemophilus influenzae in Japanese children has been increasing rapidly. Drug resistance in BLNAR strains is associated with mutations of the fts I gene, which encodes penicillin-binding protein 3. In the otolaryngological field, only a few reports have been available concerning fts I gene mutations in BLNAR. We investigated the prevalence of fts I gene mutations, by polymerase chain reaction (PCR) genotyping, in H. influenzae isolates from the upper respiratory tracts of children in the Sapporo district, Japan. When the isolates were classified according to PCR genotyping, 34 (44.2%) of 77 isolates were beta-lactamase-negative ampicillin-sensitive (g-BLNAS), 8 (10.4%) were g-low-BLNAR, 30 (39.0%) were g-high-BLNAR, 2 (2.6%) were beta-lactamase-positive ampicillin-resistant (g-BLPAR), and 3 (3.9%) were beta-lactamase-positive ampicillin/clavulanic acid-resistant (g-high-BLPACR). Mutations in the fts I gene were generally parallel to ampicillin susceptibility, and were frequently observed in children who were 7 years or younger. Of the beta-lactams tested, cefditoren showed the strongest inhibition of H. influenzae isolates, and it inhibited g-BLNAR and g-BLPACR. This study revealed a remarkably high prevalence of fts I gene mutations (g-BLNAR and g-BLPACR) in our district. Furthermore, a regional difference in the prevalence of fts I gene mutations was observed even at the district level.

  19. Comparison of PCR-based methods for the simultaneous detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in clinical samples

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    Ivano de Filippis

    Full Text Available Abstract Background Several in-house PCR-based assays have been described for the detection of bacterial meningitis caused by Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae from clinical samples. PCR-based methods targeting different bacterial genes are frequently used by different laboratories worldwide, but no standard method has ever been established. The aim of our study was to compare different in-house and a commercial PCR-based tests for the detection of bacterial pathogens causing meningitis and invasive disease in humans. Methods A total of 110 isolates and 134 clinical samples (99 cerebrospinal fluid and 35 blood samples collected from suspected cases of invasive disease were analyzed. Specific sets of primers frequently used for PCR-diagnosis of the three pathogens were used and compared with the results achieved using the multiplex approach described here. Several different gene targets were used for each microorganism, namely ctrA, crgA and nspA for N. meningitidis, ply for S. pneumoniae, P6 and bexA for H. influenzae. Results All used methods were fast, specific and sensitive, while some of the targets used for the in-house PCR assay detected lower concentrations of genomic DNA than the commercial method. An additional PCR reaction is described for the differentiation of capsulated and non-capsulated H. influenzae strains, the while commercial method only detects capsulated strains. Conclusions The in-house PCR methods here compared showed to be rapid, sensitive, highly specific, and cheaper than commercial methods. The in-house PCR methods could be easily adopted by public laboratories of developing countries for diagnostic purposes. The best results were achieved using primers targeting the genes nspA, ply, and P6 which were able to detect the lowest DNA concentrations for each specific target.

  20. Non-capsulated and capsulated Haemophilus influenzae in children with acute otitis media in Venezuela: a prospective epidemiological study

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    Naranjo Laura

    2012-02-01

    Full Text Available Abstract Background Non-typeable Haemophilus influenzae (NTHi and Streptococcus pneumoniae are major causes of bacterial acute otitis media (AOM. Data regarding AOM are limited in Latin America. This is the first active surveillance in a private setting in Venezuela to characterize the bacterial etiology of AOM in children Methods Between December 2008 and December 2009, 91 AOM episodes (including sporadic, recurrent and treatment failures were studied in 87 children enrolled into a medical center in Caracas, Venezuela. Middle ear fluid samples were collected either by tympanocentesis or spontaneous otorrhea swab sampling method. Standard laboratory and microbiological techniques were used to identify bacteria and test for antimicrobial resistance. The results were interpreted according to Clinical Laboratory Standards Institute (CLSI 2009 for non-meningitis isolates. All statistical analyses were performed using SAS 9.1 and Microsoft Excel (for graphical purposes. Results Overall, bacteria were cultured from 69.2% (63 of the 91 episodes; at least one pathogen (S. pneumoniae, H. influenzae, S. pyogenes or M. catarrhalis was cultured from 65.9% (60/91 of episodes. H. influenzae (55.5%; 35/63 episodes and S. pneumoniae (34.9%; 22/63 episodes were the most frequently reported bacteria. Among H. influenzae isolates, 62.9% (22/35 episodes were non-capsulated (NTHi and 31.4% (11/35 episodes were capsulated including types d, a, c and f, across all age groups. Low antibiotic resistance for H. influenzae was observed to amoxicillin/ampicillin (5.7%; 2/35 samples. NTHi was isolated in four of the six H. influenzae positive samples (66.7% from recurrent episodes. Conclusions We found H. influenzae and S. pneumoniae to be the main pathogens causing AOM in Venezuela. Pneumococcal conjugate vaccines with efficacy against these bacterial pathogens may have the potential to maximize protection against AOM.

  1. Comparative efficacy of oral rifampin and topical chloramphenicol in eradicating conjunctival carriage of Haemophilus influenzae biogroup aegyptius. Brazilian Purpuric Fever Study Group.

    Science.gov (United States)

    Perkins, B A; Tondella, M L; Bortolotto, I M; Takano, O A; da Silva, G A; Irino, K; Brandileone, M C; Harrison, L H; Wenger, J D; Broome, C V

    1992-09-01

    Persistent conjunctival carriage of the Haemophilus influenzae biogroup aegyptius (Hae) strain (BPF clone) responsible for Brazilian purpuric fever (BPF) has been documented. Topical chloramphenicol is routinely used to treat conjunctivitis in areas affected by BPF in Brazil. Although the BPF clone is susceptible to chloramphenicol, we observed a number of children treated with topical chloramphenicol for conjunctivitis who still developed BPF. During an investigation of an outbreak of BPF in Mato Grosso State, Brazil, we compared oral rifampin (20 mg/kg/day for 4 days) with topical chloramphenicol for eradication of conjunctival carriage of H. influenzae biogroup aegyptius among children with presumed BPF clone conjunctivitis. Conjunctival samples were taken for culture on the day treatment was initiated and a mean of 8 and 21 days later. At 8 days the eradication rates for oral rifampin and topical chloramphenicol were 100 and 44%, respectively (P = 0.003); at 21 days they were 100 and 50% (P = 0.01). Oral rifampin was more effective than topical chloramphenicol for eradication of the BPF clone and may be useful in prevention of BPF.

  2. Non-epitope-specific suppression of the antibody response to Haemophilus influenzae type b conjugate vaccines by preimmunization with vaccine components

    DEFF Research Database (Denmark)

    Barington, T; Skettrup, M; Juul, L;

    1993-01-01

    Recently, conjugate vaccines containing Haemophilus influenzae type b capsular polysaccharide (HibCP) coupled to protein carriers were introduced for use in infants and certain adult risk groups. Similar conjugate vaccines against other capsulated bacteria are currently under development for both...

  3. Heavy-chain isotype patterns of human antibody-secreting cells induced by Haemophilus influenzae type b conjugate vaccines in relation to age and preimmunity

    DEFF Research Database (Denmark)

    Barington, T; Juul, Lars; Gyhrs, A;

    1994-01-01

    The influence of preexisting immunity on the heavy-chain isotypes of circulating antibody-secreting cells (AbSC) induced by vaccination with Haemophilus influenzae type b (Hib) capsular polysaccharide (HibCP) coupled to tetanus toxoid (TT) or diphtheria toxoid (DT) and by vaccination with TT or DT...

  4. A simplification of the enzyme-linked immunospot technique. Increased sensitivity for cells secreting IgG antibodies to Haemophilus influenzae type b capsular polysaccharide

    DEFF Research Database (Denmark)

    Barington, T; Sparholt, S; Juul, L

    1992-01-01

    A simplified enzyme-linked immunospot (ELISPOT) technique is described for the detection of cells secreting antibodies to tetanus toxoid (TT), diphtheria toxoid (DT) or Haemophilus influenzae type b capsular polysaccharide (PRP). By combining the cell suspension with the enzyme-linked secondary...

  5. Haemophilus influenzae type b and its vaccines%b型流感嗜血杆菌及其疫苗

    Institute of Scientific and Technical Information of China (English)

    尹珊珊; 高正伦; 刘建凯; 郑海发

    2014-01-01

    b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)是导致婴幼儿严重细菌性感染的主要致病菌之一.Hib疫苗的研发和使用大大降低了Hib疾病的发病率.研究显示,Hib结合疫苗可有效预防婴幼儿侵袭性Hib疾病,且具有良好的安全性.此文就Hib的病原学、流行病学及疫苗研究进行综述.%Haemophilus influenzae type b (Hib) is one of the major causes of severe bacterial infections in infants and young children.With development and usage of Hib vaccines,incidence rate of Hib diseases reduces significantly.Researches show that Hib conjugate vaccine can effectively prevent invasive Hib diseases in infants and young children and has good safety.This article reviews etiology,epidemiology and vaccine research of Hib.

  6. Haemophilus influenzae isolates survive for up to 20 years at -70 °C in skim milk tryptone glucose glycerol broth (STGGB) if thawing is avoided during re-culture.

    Science.gov (United States)

    Hare, K M; Smith-Vaughan, H C; Beissbarth, J; Leach, A J

    2015-12-01

    Haemophilus influenzae remains a major cause of disease worldwide requiring continued study. Recently, isolates of Streptococcus pneumoniae and Moraxella catarrhalis, but not H. influenzae, were reported to survive long-term ultra-freeze storage in STGGB. We show that nontypeable H. influenzae isolates survive for up to 20 years when thawing is avoided.

  7. Identification of immunogenic outer membrane proteins of Haemophilus influenzae type b in the infant rat model system

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    Hansen, E.J.; Frisch, C.F.; McDade, R.L. Jr.; Johnston, K.H.

    1981-06-01

    Outer membrane proteins of Haemophilus influenzae type b which are immunogenic in infant rats were identified by a radioimmunoprecipitation method. Intact cells of H. influenzae type b were radioiodinated by a lactoperoxidase-catalyzed procedure, and an outer membrane-containing fraction was prepared from these cells. These radioiodinated outer membranes were mixed with sera obtained from rats convalescing from systemic H. influenzae type b disease induced at 6 days of age, and the resultant (antibody-outer membrane protein antigen) complexes were extracted from these membranes by treatment with nonionic detergent and ethylenediaminetetraacetic acid. These soluble antibody-antigen complexes were isolated by means of adsorption to protein A-bearing staphylococci, and the radioiodinated protein antigens were identified by gel electrophoresis followed by autoradiography. Infant rats were shown to mount a readily detectable antibody response to several different proteins present in the outer membrane of H. influenzae type b. Individual infant rats were found to vary both qualitatively and quantitatively in their immune response to these immunogenic outer membrane proteins.

  8. The roles of epithelial cell contact, respiratory bacterial interactions and phosphorylcholine in promoting biofilm formation by Streptococcus pneumoniae and nontypeable Haemophilus influenzae.

    Science.gov (United States)

    Krishnamurthy, Ajay; Kyd, Jennelle

    2014-08-01

    Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi) often share a common niche within the nasopharynx, both associated with infections such as bronchitis and otitis media. This study investigated how the association between NTHi and S. pneumoniae and the host affects their propensity to form biofilms. We investigated a selection of bacterial strain and serotype combinations on biofilm formation, and the effect of contact with respiratory epithelial cells. Measurement of biofilm showed that co-infection with NTHi and S. pneumoniae increased biofilm formation following contact with epithelial cells compared to no contact demonstrating the role of epithelial cells in biofilm formation. Additionally, the influence of phosphorylcholine (ChoP) on biofilm production was investigated using the licD mutant strain of NTHi 2019 and found that ChoP had a role in mixed biofilm formation but was not the only requirement. The study highlights the complex interactions between microbes and the host epithelium during biofilm production, suggesting the importance of understanding why certain strains and serotypes differentially influence biofilm formation. A key contributor to increased biofilm formation was the upregulation of biofilm formation by epithelial cell factors.

  9. Proposed second class of Haemophilus ducreyi strains show altered protein and lipooligosaccharide profiles.

    Science.gov (United States)

    Post, Deborah M B; Gibson, Bradford W

    2007-09-01

    Haemophilus ducreyi is the etiologic agent of chancroid, a sexually transmitted genital ulcer disease. Previously we have shown that the protein profiles and lipooligosaccharide (LOS) structures from various strains of H. ducreyi are generally well conserved. Previous studies have demonstrated that at least one strain, 33921, has a variant protein profile and LOS structure. In this study, both the whole cell lysate and the membrane proteins from strain 33921 were further examined and compared to the prototypical strain 35000HP by 2-DE and by the 16-BAC (benzyldimethyl-n-hexadecylammonium chloride)/SDS-PAGE two-detergent system, respectively. These comparisons demonstrated that a number of the proteins that could be identified from both strains had altered positions on the gels, both in their apparent molecular weight and pI values. Strain 33921 has been suggested to be a member of a second class of strains, termed class II strains. In this study, the proteomic profiles and the LOS structures from the five potential class II strains were examined and found to be similar to strain 33921.

  10. Relative Contribution of P5 and Hap Surface Proteins to Nontypable Haemophilus influenzae Interplay with the Host Upper and Lower Airways.

    Science.gov (United States)

    Euba, Begoña; Moleres, Javier; Viadas, Cristina; Ruiz de los Mozos, Igor; Valle, Jaione; Bengoechea, José Antonio; Garmendia, Junkal

    2015-01-01

    Nontypable Haemophilus influenzae (NTHi) is a major cause of opportunistic respiratory tract disease, and initiates infection by colonizing the nasopharynx. Bacterial surface proteins play determining roles in the NTHi-airways interplay, but their specific and relative contribution to colonization and infection of the respiratory tract has not been addressed comprehensively. In this study, we focused on the ompP5 and hap genes, present in all H. influenzae genome sequenced isolates, and encoding the P5 and Hap surface proteins, respectively. We employed isogenic single and double mutants of the ompP5 and hap genes generated in the pathogenic strain NTHi375 to evaluate P5 and Hap contribution to biofilm growth under continuous flow, to NTHi adhesion, and invasion/phagocytosis on nasal, pharyngeal, bronchial, alveolar cultured epithelial cells and alveolar macrophages, and to NTHi murine pulmonary infection. We show that P5 is not required for bacterial biofilm growth, but it is involved in NTHi interplay with respiratory cells and in mouse lung infection. Mechanistically, P5NTHi375 is not a ligand for CEACAM1 or α5 integrin receptors. Hap involvement in NTHi375-host interaction was shown to be limited, despite promoting bacterial cell adhesion when expressed in H. influenzae RdKW20. We also show that Hap does not contribute to bacterial biofilm growth, and that its absence partially restores the deficiency in lung infection observed for the ΔompP5 mutant. Altogether, this work frames the relative importance of the P5 and Hap surface proteins in NTHi virulence.

  11. Relationships between Mucosal Antibodies, Non-Typeable Haemophilus influenzae (NTHi) Infection and Airway Inflammation in COPD.

    Science.gov (United States)

    Staples, Karl J; Taylor, Stephen; Thomas, Steve; Leung, Stephanie; Cox, Karen; Pascal, Thierry G; Ostridge, Kristoffer; Welch, Lindsay; Tuck, Andrew C; Clarke, Stuart C; Gorringe, Andrew; Wilkinson, Tom M A

    2016-01-01

    Non-typeable Haemophilus influenzae (NTHi) is a key pathogen in COPD, being associated with airway inflammation and risk of exacerbation. Why some patients are susceptible to colonisation is not understood. We hypothesised that this susceptibility may be due to a deficiency in mucosal humoral immunity. The aim of our study (NCT01701869) was to quantify the amount and specificity of antibodies against NTHi in the lungs and the associated risk of infection and inflammation in health and COPD. Phlebotomy, sputum induction and bronchoscopy were performed on 24 mild-to-moderate COPD patients and 8 age and smoking-matched controls. BAL (Bronchoalveolar lavage) total IgG1, IgG2, IgG3, IgM and IgA concentrations were significantly increased in COPD patients compared to controls. NTHi was detected in the lungs of 7 of the COPD patients (NTHi+ve-29%) and these patients had a higher median number of previous exacerbations than NTHi-ve patients as well as evidence of increased systemic inflammation. When comparing NTHi+ve versus NTHi-ve patients we observed a decrease in the amount of both total IgG1 (p = 0.0068) and NTHi-specific IgG1 (p = 0.0433) in the BAL of NTHi+ve patients, but no differences in total IgA or IgM. We observed no evidence of decreased IgG1 in the serum of NTHi+ve patients, suggesting this phenomenon is restricted to the airway. Furthermore, the NTHi+ve patients had significantly greater levels of IL-1β (p = 0.0003), in BAL than NTHi-ve COPD patients.This study indicates that the presence of NTHi is associated with reduced levels and function of IgG1 in the airway of NTHi-colonised COPD patients. This decrease in total and NTHI-specific IgG1 was associated with greater systemic and airway inflammation and a history of more frequent exacerbations and may explain the susceptibility of some COPD patients to the impacts of NTHi.

  12. HadA is an atypical new multifunctional trimeric coiled-coil adhesin of Haemophilus influenzae biogroup aegyptius, which promotes entry into host cells.

    Science.gov (United States)

    Serruto, Davide; Spadafina, Tiziana; Scarselli, Maria; Bambini, Stefania; Comanducci, Maurizio; Höhle, Sonja; Kilian, Mogens; Veiga, Esteban; Cossart, Pascale; Oggioni, Marco R; Savino, Silvana; Ferlenghi, Ilaria; Taddei, Anna Rita; Rappuoli, Rino; Pizza, Mariagrazia; Masignani, Vega; Aricò, Beatrice

    2009-07-01

    The Oca (Oligomeric coiled-coil adhesin) family is a subgroup of the bacterial trimeric autotransporter adhesins, which includes structurally related proteins, such as YadA of Yersinia enterocolitica and NadA of Neisseria meningitidis. In this study, we searched in silico for novel members of this family in bacterial genomes and identified HadA (Haemophilus adhesin A), a trimeric autotransporter expressed only by Haemophilus influenzae biogroup aegyptius causing Brazilian purpuric fever (BPF), a fulminant septicemic disease of children. By comparative genomics and sequence analysis we predicted that the hadA gene is harboured on a mobile genetic element unique to BPF isolates. Biological analysis of HadA in the native background was limited because this organism is not amenable to genetic manipulation. Alternatively, we demonstrated that expression of HadA confers to a non-invasive Escherichia coli strain the ability to adhere to human cells and to extracellular matrix proteins and to induce in vitro bacterial aggregation and microcolony formation. Intriguingly, HadA is predicted to lack the typical N-terminal head domain of Oca proteins generally associated with cellular receptor binding. We propose here a structural model of the HadA coiled-coil stalk and show that the N-terminal region is still responsible of the binding activity and a KGD motif plays a role. Interestingly, HadA promotes bacterial entry into mammalian cells. Our results show a cytoskeleton re-arrangement and an involvement of clathrin in the HadA-mediated internalization. These data give new insights on the structure-function relationship of oligomeric coiled-coil adhesins and suggest a potential role of this protein in the pathogenesis of BPF.

  13. Peroxiredoxin-glutaredoxin and catalase promote resistance of nontypeable Haemophilus influenzae 86-028NP to oxidants and survival within neutrophil extracellular traps.

    Science.gov (United States)

    Juneau, Richard A; Pang, Bing; Armbruster, Chelsie E; Murrah, Kyle A; Perez, Antonia C; Swords, W Edward

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHI) is a common commensal and opportunistic pathogen of the human airways. For example, NTHI is a leading cause of otitis media and is the most common cause of airway infections associated with chronic obstructive pulmonary disease (COPD). These infections are often chronic/recurrent in nature and involve bacterial persistence within biofilm communities that are highly resistant to host clearance. Our previous work has shown that NTHI within biofilms has increased expression of factors associated with oxidative stress responses. The goal of this study was to define the roles of catalase (encoded by hktE) and a bifunctional peroxiredoxin-glutaredoxin (encoded by pdgX) in resistance of NTHI to oxidants and persistence in vivo. Isogenic NTHI strain 86-028NP mutants lacking hktE and pdgX had increased susceptibility to peroxide. Moreover, these strains had persistence defects in the chinchilla infection model for otitis media, as well as in a murine model for COPD. Additional work showed that pdgX and hktE were important determinants of NTHI survival within neutrophil extracellular traps (NETs), which we have shown to be an integral part of NTHI biofilms in vivo. Based on these data, we conclude that catalase and peroxiredoxin-glutaredoxin are determinants of bacterial persistence during chronic/recurrent NTHI infections that promote bacterial survival within NETs.

  14. Antibody to a 145-kilodalton outer membrane protein has bactericidal activity and protective activity against experimental bacteremia caused by a Brazilian purpuric fever isolate of Haemophilus influenzae biogroup aegyptius. The Brazilian Purpuric Fever Study Group.

    Science.gov (United States)

    Rubin, L G; Rizvi, A

    1991-12-01

    The immunologic basis for protection against Brazilian purpuric fever, a septicemic infection associated with Haemophilus influenzae biogroup aegyptius bacteremia, is unknown. Passive immunization of infant rats with antiserum to whole bacterial cells of the homologous strain protects them from experimental bacteremia following bacterial challenge. In immunoblotting, antibody to a 145-kDa protein (P145) was present in protective antisera but not in nonprotective antisera. As judged by analysis of the antibodies eluted from whole bacterial cells and the agglutination of bacteria by antisera to P145, this protein is surface exposed. We prepared monospecific rat antisera to this protein by three methods: (i) immunization with whole bacterial cells and absorption with a Brazilian purpuric fever strain not expressing P145, (ii) immunization with gel-purified P145, and (iii) immunization with a P145-expressing transformant of a laboratory H. influenzae strain expressing this protein and absorption of the antiserum with the laboratory H. influenzae strain. These antisera had low antilipooligosaccharide antibody titers, were reactive only with P145, and had bactericidal activity in vitro. Following passive immunization, these antisera partially protected infant rats from bacteremia resulting from intraperitoneal challenge with bacteria. As assessed by immunoblotting, pooled adult human sera contained antibodies reactive with P145. Antibody to P145 may contribute to protection against Brazilian purpuric fever.

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

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    Jordan R Gaston

    Full Text Available 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.

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

    Science.gov (United States)

    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. Haemophilus influenzae tipo b: situação epidemiológica no Estado de Minas Gerais, Brasil, 1993 a 1997 Haemophilus influenzae type b: epidemiological situation in the State of Minas Gerais, Brazil, 1993-1997

    Directory of Open Access Journals (Sweden)

    Sybelle de Souza Castro Miranzi

    2003-10-01

    Full Text Available Entre as doenças invasivas causadas pelo Haemophilus influenzae tipo b (Hib, destacam-se, pela freqüência e gravidade, as pneumonias e as meningites. No período de 1993 a 1997, foram notificados, em Minas Gerais, 720 casos de meningites por Hib, sendo a causa mais freqüente de meningite bacteriana em menores de um ano e a segunda causa no total de meningites. Entretanto, estimou-se uma ocorrência total de 1.160 casos considerando as meningites bacterianas não especificadas. O total de casos estimados de doença invasiva por Hib parece justificar a recente inclusão da vacina no esquema básico de imunizações. O alto custo da vacina reforça a necessidade de melhorar a vigilância epidemiológica da meningite, que constitui uma das fragilidades das ações de controle desta doença.Among Haemophilus influenzae type b (Hib invasive diseases, pneumonia and meningitis are the most relevant in public health due to their frequency and severity. From 1993 to 1997, there were 720 cases of Hib meningitis in Minas Gerais State, Brazil, representing the most frequent cause of bacterial meningitis in infants (< 1 year and the second most frequent among all causes of meningitis. The total estimated cases of invasive Hib diseases thus appear to justify the recent inclusion of the vaccine in the basic immunization protocol. The vaccine's high cost reinforces the need for more precise monitoring of the etiological diagnosis of meningitis cases, representing one of the weaknesses in the prevailing epidemiological surveillance system.

  18. Impact of the Haemophilus influenzae type b vaccination program on HIB meningitis in Brazil Impacto do programa de vacinação contra meningites causadas por Haemophilus influenzae tipo b no Brasil

    Directory of Open Access Journals (Sweden)

    Sybelle de Souza Castro Miranzi

    2007-07-01

    Full Text Available This study aimed to evaluate the impact of vaccination against Haemophilus influenzae type b (HIB in Brazil on the morbidity, mortality, and case fatality of HIB meningitis, using the Ministry of Health database and population data from the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística - IBGE. Impact was evaluated through a time series analysis (1983-2002, using regression forecasting (RF by dividing the time series into two periods: (a historical (1983-1998 and (b validation (1999-2002. Impact of the vaccination was positive, although more significant for incidence and mortality than for case fatality rates.A proposta deste trabalho foi avaliar o impacto da vacinação contra Haemophilus influenzae tipo b (HIB no Brasil sobre a morbi-mortalidade e a letalidade das meningites por HIB, a partir de base de dados fornecida pelo Ministério da Saúde e as estimativas populacionais provenientes do Instituto Brasileiro de Geografia e Estatística (IBGE. Para a avaliação do impacto utilizou-se análise de tendência temporal (1983-2002, aplicando-se a técnica RF (regression forecasting, dividindo-se a série em dois períodos: (a período histórico (1983-1998 e (b período de estimação (1999-2002. O impacto da vacinação foi positivo, embora tenha se revelado mais expressivo sobre a morbi-mortalidade que sobre a letalidade.

  19. The iron/heme regulated genes of Haemophilus influenzae: comparative transcriptional profiling as a tool to define the species core modulon

    Directory of Open Access Journals (Sweden)

    Morton Daniel J

    2009-01-01

    Full Text Available Abstract Background Haemophilus influenzae requires heme for aerobic growth and possesses multiple mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps in our knowledge remain. Unresolved issues include the identities of all genes exhibiting altered transcription in response to iron and heme availability, the fraction of such genes functioning in iron/heme acquisition, and the heterogeneity of this gene set among clinical isolates. Previously we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those observations by determining the iron/heme modulons of two clinical isolates, the type b isolate 10810 and the nontypeable isolate R2866. These data are used to begin to define the core iron/heme modulon of the species. Results Microarray studies were performed to compare gene expression on transition from iron/heme-restricted to iron/heme-replete conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed: 233 were maximally transcribed under iron/heme-replete conditions and 130 under iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain 10810, 353 were significantly differentially transcribed: 150 were preferentially transcribed under iron/heme-replete conditions and 203 under iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes exhibited similar regulation in both isolates and that 74 of these exhibited similar patterns of regulation in Rd KW20. These comprise the putative core iron/heme modulon. Conclusion This study provides evidence for a conserved core of H. influenzae genes the transcription of which is altered by the availability of

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

    Science.gov (United States)

    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).

  1. Significance of tagI and mfd genes in the virulence of non-typeable Haemophilus influenzae.

    Science.gov (United States)

    Spricigo, Denis A; Cortés, Pilar; Moranta, David; Barbé, Jordi; Bengoechea, José Antonio; Lagostera, Montserrat

    2014-09-01

    Non-typeable Haemophilus influenzae (NTHi) is an opportunist pathogen well adapted to the human upper respiratory tract and responsible for many respiratory diseases. In the human airway, NTHi is exposed to pollutants, such as alkylating agents, that damage its DNA. In this study, we examined the significance of genes involved in the repair of DNA alkylation damage in NTHi virulence. Two knockout mutants, tagI and mfd, encoding N³-methyladenine-DNA glycosylase I and the key protein involved in transcription-coupled repair, respectively, were constructed and their virulence in a BALB/c mice model was examined. This work shows that N³-methyladenine-DNA glycosylase I is constitutively expressed in NTHi and that it is relevant for its virulence.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mirza,I.; Nazi, I.; Korczynska, M.; Wright, G.; Berghuis, A.

    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 properties 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.

  4. Coverage and causes of missed Haemophilus influenzae type B vaccination in urban and rural areas of Peshawar.

    Science.gov (United States)

    Naeem, Mohammad; Adil, Muhammad; Abbas, Syed Hussain; Khan, Muhammad Zia Ul Islam; Naz, Syeda Maria; Khan, Ayasha; Khan, Muhammad Usman

    2011-01-01

    Haemophilus influenza type b (Hib) is a major cause of morbidity and mortality in Pakistan. Hib vaccine was introduced in 2009 in EPI programme. The purpose of this study was to find out the coverage and factors associated with non-immunization of Hib in urban and rural areas of Peshawar. Data was collected through random sampling in Peshawar University, Peshawar Saddar, Hashtnagri, Naway Kalay and Pawaka from 9th to 19th of June 2010. A questionnaire was used to interview parents of 600 children aged 1 year and below about demographics, Hib vaccination status, reasons for missed vaccination and views on immunization. Pearson's Chi-square test was used for statistical testing, and pfear of reaction (5.4%), child illness (8.1%) and miscellaneous causes (13.7%). Low Hib vaccination coverage in Peshawar is mainly due to low awareness among people, poor economic conditions and illiteracy.

  5. The effects of disodium cromoglycate on enhanced adherence of Haemophilus influenzae to A549 cells infected with respiratory syncytial virus.

    Science.gov (United States)

    Fukasawa, Chie; Ishiwada, Naruhiko; Ogita, Junko; Hishiki, Haruka; Kohno, Yoichi

    2009-08-01

    Nontypeable Haemophilus influenzae (NTHi) secondary infection often complicates respiratory syncytial virus (RSV) infections. Previous studies have revealed that RSV infections enhance NTHi adherence to airway epithelial cells. In this study, we investigated the effects of disodium cromoglycate (DSCG) and corticosteroids, which are frequently used for the treatment of wheezing often related to RSV infections, on the adherence of NTHi to RSV-infected A549 cells. DSCG inhibited enhanced adherence of NTHi to RSV-infected A549 cells, whereas dexamethasone (Dex) and fluticasone propionate (Fp) did not. DSCG suppressed the expression of ICAM-1, which is one of the NTHi receptors. Furthermore, DSCG exhibited an inhibitory effect on RSV infections. It is suggested that DSCG exerts an anti-RSV effect, and consequently attenuates the expression of NTHi receptors.

  6. ModA2 Phasevarion Switching in Nontypeable Haemophilus influenzae Increases the Severity of Experimental Otitis Media.

    Science.gov (United States)

    Brockman, Kenneth L; Jurcisek, Joseph A; Atack, John M; Srikhanta, Yogitha N; Jennings, Michael P; Bakaletz, Lauren O

    2016-09-01

    Several human-adapted bacterial pathogens use a phasevarion (ie, a phase-variable regulon) to rapidly and reversibly regulate the expression of many genes, which include known virulence factors, yet the influence of phasevarion-mediated regulation in pathogenesis remains poorly understood. Here we examine the impact of the nontypeable Haemophilus influenzae (NTHI) ModA2 phasevarion on pathogenesis and disease severity in a chinchilla model of experimental otitis media. Chinchillas were challenged with NTHI variant populations that were either inoculated ON and remained ON, inoculated OFF and shifted ON, or inoculated OFF and remained OFF, within the middle ear. We show that populations that shift from OFF to ON within the middle ear induce significantly greater disease severity than populations that are unable to shift. These observations support the importance of phasevarion switching in NTHI pathogenesis and the necessity to considered phasevarion regulation when developing methods to treat and prevent infection.

  7. Erythromycin and azithromycin transport into Haemophilus influenzae ATCC 19418 under conditions of depressed proton motive force (delta mu H)

    Energy Technology Data Exchange (ETDEWEB)

    Capobianco, J.O.; Goldman, R.C. (Abbott Laboratories, IL (USA))

    1990-09-01

    The effect of collapsing the electrochemical proton gradient (delta mu H) on ({sup 3}H)erythromycin and ({sup 14}C)azithromycin transport in Haemophilus influenzae ATCC 19418 was studied. The proton gradient and membrane potential were determined from the distribution of (2-{sup 14}C)dimethadione and rubidium-86, respectively. delta mu H was reduced from 124 to 3 mV in EDTA-valinomycin-treated cells at 22{degrees}C with 150 mM KCl and 0.1 mM carbonyl cyanide m-chlorophenylhydrazone. During the collapse of delta mu H, macrolide uptake increased. Erythromycin efflux studies strongly suggested that this increase was not due to an energy-dependent efflux pump but was likely due to increased outer membrane permeability. These data indicated that macrolide entry was not a delta mu H-driven active transport process but rather a passive diffusion process.

  8. Isolation and characterization of a UV-sensitive mutator (mutB1) mutant of Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Walter, R.B.; Stuy, J.H.

    1988-06-01

    The mutB1 mutant of Haemophilus influenzae is very sensitive to UV radiation but only slightly sensitive to methylmethane sulfonate or N-methyl-N'-nitro-N-nitrosoguanidine. Cultures of mutB1 cells contain high numbers of spontaneous mutants and show hypermutability after exposure to the latter mutagen. Normally high-efficiency transforming markers, as well as low-efficiency ones, transform mutB1 recipients at similarly low efficiencies. Significant host cell reactivation was observed when mutB1 cells were exposed to UV-damaged phage; however, these mutants showed a decrease in phage recombination. This mutant did not degrade its DNA following exposure to UV. It is speculated that the mutB1 mutation is similar to the Escherichia coli uvrD mutation.

  9. International collaborative study for establishment of the 2nd WHO International Standard for Haemophilus influenzae type b polysaccharide.

    Science.gov (United States)

    Mawas, Fatme; Burkin, Karena; Dougall, Thomas; Saydam, Manolya; Rigsby, Peter; Bolgiano, Barbara

    2015-11-01

    In this report we present the results of a collaborative study for the preparation and calibration of a replacement International Standard (IS) for Haemophilus influenzae type b polysaccharide (polyribosyl ribitol phosphate; 5-d-ribitol-(1 → 1)-β-d-ribose-3-phosphate; PRP). Two candidate preparations were evaluated. Thirteen laboratories from 9 different countries participated in the collaborative study to assess the suitability and determine the PRP content of two candidate standards. On the basis of the results from this study, Candidate 2 (NIBSC code 12/306) has been established as the 2nd WHO IS for PRP by the Expert Committee of Biological Standards of the World Health Organisation with a content of 4.904 ± 0.185mg/ampoule, as determined by the ribose assays carried out by 11 of the participating laboratories.

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

    Science.gov (United States)

    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. Carriage of Haemophilus influenzae in the oropharynx of young children and molecular epidemiology of the isolates after fifteen years of H. influenzae type b vaccination in Italy.

    Science.gov (United States)

    Giufrè, Maria; Daprai, Laura; Cardines, Rita; Bernaschi, Paola; Ravà, Lucilla; Accogli, Marisa; Raponi, Massimiliano; Garlaschi, Maria Laura; Ciofi degli Atti, Marta Luisa; Cerquetti, Marina

    2015-11-17

    Haemophilus influenzae is an important pathogen able to cause a wide spectrum of diseases in children. Colonization of the upper respiratory tract is a risk factor for developing disease. This study aimed to investigate the oropharyngeal carriage rate of H. influenzae in young children in two Italian cities, 15 years after H. influenzae type b (Hib) vaccination was introduced. Antibiotic resistant traits and genotypes of the colonizing H. influenzae isolates were investigated. Oropharyngeal swabs were obtained from 717 healthy children aged <6 years (June 2012-July 2013). Potential risk factors for H. influenzae colonization were investigated. H. influenzae isolates from carriage were characterized by PCR capsular typing, ampicillin susceptibility testing, resistance-associated gene sequencing and multilocus sequence typing (MLST). For comparison purposes, 38 non-typeable H. influenzae (NTHi) isolates from invasive disease were genotyped by MLST. The overall H. influenzae carriage rate was 14.1% (101/717). Age, study site, presence of young siblings, and complete Hib vaccination status were independently associated with colonization. Of 101 isolates, 98 were NTHi, 2 were type e and 1 was type f. The overall ampicillin resistance rate was 15.8% (16/101). Resistance was mediated by TEM-1 β-lactamase production in half of isolates (n=8) or modifications in penicillin-binding protein (PBP) 3 in the other half (n=8). Several substitutions were discovered in PBP3 including the Asn526Lys change. Seventy-six different STs were identified among 98 NTHi isolates from carriage, with only 4 STs (ST12, ST57, ST238, ST1238) encompassing ≥ 3 isolates. Comparison of carriage and disease isolates found that several STs were shared between the two sources, although none of the major disease-associated STs were observed in carriage isolates. NTHi is the predominant serotype in carriage. The importance of monitoring both NTHi colonization rate and circulating genotypes should be

  12. Ocorrência de Haemophilus influenzae em crianças atendidas em creches

    Directory of Open Access Journals (Sweden)

    J. M. MARIN

    2009-01-01

    Full Text Available

    As doenças provocadas por cepas de Haemophilus influenzae tipo b (Hib, como por exemplo, conjuntivite, otite média, meningite e pericardite têm apresentado uma sensível diminuição em resposta ao uso da vacina anti Hib no esquema de vacinação nacional. No entanto, com a eliminação da colonização da nasofaringe por Hib, abre-se a possibilidade da substituição de cepas colonizadoras que apresentam este sorotipo capsular por outros sorotipos ou pela colonização por H. influenzae não tipavel (NTHi. Neste sentido, as creches representam um fator de risco para a transmissão das bactérias em função do prolongado e intenso contacto entre as crianças neste ambiente. O objetivo do presente estudo foi apresentar uma revisão atualizada sobre a colonização e transmissão de H. influenzae em crianças saudáveis que freqüentam creches. Concluiu-se que as crianças que freqüentam creches devem ser continuamente monitoradas, para se verificar a eliminação da colonização na nasofaringe por Hib ou a sua substituição por cepas de outros sorotipos ou NTHi. Palavras-chave: Haemophilus influenzae, creche, transmissão, vacina anti Hib.

  13. Correlation between clinico-pathological outcome and typing of Haemophilus parasuis field strains.

    Science.gov (United States)

    Aragon, Virginia; Cerdà-Cuéllar, Marta; Fraile, Lorenzo; Mombarg, Mark; Nofrarías, Miquel; Olvera, Alexandre; Sibila, Marina; Solanes, David; Segalés, Joaquim

    2010-05-19

    Haemophilus parasuis is the etiologic agent of Glässer's disease in pigs, which is pathologically characterized by serofibrinous polyserositis and arthritis. H. parasuis include virulent and non-virulent strains and confirmation of virulence in H. parasuis is still dependent on experimental reproduction of the disease. Since the variability in virulence is supported by serotyping and genotyping (particularly, multilocus sequence typing [MLST]), we examined the relationship between the classification of 8 field strains by these methods and their capacity to cause disease in snatch-farrowed, colostrum-deprived piglets. The severity of clinical signs and lesions produced by the different strains correlated with the quantity of H. parasuis recovered from the lesions. However, the virulence of the strains in the animal model did not show a total correlation with their serovar or their classification by MLST. More stu