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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adherence to human epithelial cells, biotype and capsular type of 175 Haemophilus influenzae cultured from the upper respiratory tract were studied in a prospective study of children with recurrent otitis media. Forty-three children who had greater than 2 episodes of acute otitis media (AOM) during the first year of life were followed for at least 1 year. Cultures of the oropharynx were done periodically, and the middle ear fluid (MEF) was cultured at the time of AOM. H. influenzae was recovered from MEF in 44% of the 136 AOM episodes recorded. Thirty-one children had at least one episode of AOM caused by H. influenzae; the remaining 12 children, designated as "controls," had no otitis or had AOM caused by other organisms. The possible differences between carriage and infection strains were evaluated by comparison of MEF and oropharyngeal isolates, by pairwise comparison of MEF and oropharyngeal isolates and by pairwise comparison of multiple isolates from each host recovered at the time of AOM and during infection-free intervals. No significant differences in patterns of adherence, capsular type or biotype were found. The lack of correlation between these characteristics and infection suggests either that H. influenzae organisms have determinants of virulence yet to be defined or that variations in host susceptibility permit infection by the strain colonizing the upper respiratory tract. Adherence per se may be less important in the development of infection than in establishing and maintaining colonization within the host.
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PMID:Lack of correlation of in vitro adherence of Haemophilus influenzae to epithelial cells with frequent occurrence of otitis media. 349 76

Because bacteria are known to persist in middle ear effusions for extended periods of time despite the presence of increasing titers of specific antibody in both sera and middle ear fluids in humans, we examined the ability of postinfection serum to opsonize Haemophilus influenzae (nontypable and type b) for phagocytosis by middle ear macrophages in chinchillas. Our data indicated that preopsonization of both strains of H influenzae enhanced phagocytosis by macrophages recruited to the middle ear following intrabullar instillation of keyhole limpet hemocyanin. Both the total number of bacteria ingested and the percentage of macrophages phagocytizing were significantly greater in the presence of postinfection serum than preinfection serum for all animals tested.
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PMID:Effect of preopsonization on phagocytosis of Haemophilus influenzae. 349 64

Cross-reactive antibodies directed against type b (TBHI) or serologically nontypeable (NTHI) strains of Hemophilus influenzae were investigated in experimental otitis media. Cross-reactive antibody to TBHI was demonstrated in sera and middle ears from chinchillas infected with an NTHI, and cross-reactive antibody to NTHI developed in sera and middle ears of chinchillas challenged with TBHI. The absorption test data presented indicate that the sera and middle ear effusions from chinchillas challenged with either TBHI or NTHI had not only specific antibody activity to the challenged strain but also antibody activities against the probable common cell antigens of H influenzae. These data indicate that it may be possible to develop a polyvalent vaccine effective against the various and divergent strains of H influenzae, including the serologically nontypeable isolates.
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PMID:Cross-reactive antibodies in type b and nontypeable Hemophilus influenzae-induced experimental otitis media. 349 41

Previously, we extracted lipopolysaccaride endotoxin (LPS) from an axenic culture of Haemophilus influenzae and inoculated it into the middle ears of guinea pigs, inducing temporary serous effusions. In the present study, we tried to clarify whether the immunological mechanism responsible for producing the otitis media following outer cell wall inoculation was persistent. We extracted the outer cell wall from nontypable H. influenzae, using Zollinger's method, and inoculated extracts into the middle ears of guinea pigs that had previously received three injections of nonviable H. influenzae in Freund's complete adjuvant. Histological evaluations were performed from day 2 to day 24. Effusions and mucosal changes persisted for a longer time than in the LPS-inoculated model. Hypertrophied mucosae and increased numbers of goblet cells with hypersecretion were visible in the specimens on days 23-24. The condition seemed to show a greater similarity to chronic otitis media with effusion in children than did the LPS-inoculated model. We concluded that both the biological activity of the outer cell wall and immunological mechanisms might induce prolonged otitis media. We speculate that not only single middle ear infection but also general infections and repetitive middle ear infections may contribute to prolonged otitis media.
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PMID:Experimentally induced otitis media with effusion following inoculation with the outer cell wall of nontypable Haemophilus influenzae. 350 Jul 5

The pathogenesis of labyrinthitis associated with bacterial meningitis was studied by histopathologic examination of inner ears of 114 rats with Haemophilus influenzae type b meningitis produced by ip inoculation of one of 13 clinical isolates. Findings consisted of inflammation of the perilymphatic spaces of the cochlea and semicircular canals with sparing of the endolymphatic space, cochlear nerve fibers, and middle ear. The degree of inflammation peaked at 48 hr after inoculation, then declined by 96 to 144 hr. No interstrain differences in type or degree of pathology were observed. Immunofluorescent staining of cochleae from 15 animals demonstrated that bacteria were present in areas of inflammation and also in the endolymphatic space and organ of Corti. One isolate displayed a tendency to accumulate in the perilymphatic spaces in larger numbers than those seen with three other isolates. These findings suggest that, in this model, inflammation reaches the inner ear by spreading from the subarachnoid space. Bacterial invasion of the organ of Corti may be one mechanism by which deafness occurs in bacterial meningitis.
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PMID:Pathogenesis of labyrinthitis associated with Haemophilus influenzae type b meningitis in infant rats. 351 Feb 60

Because Haemophilus influenzae is one of the most common pathogens in otitis media with effusion, we have investigated the antibody response in the serum and middle ear effusion (MEE) in nontypable H influenzae-induced experimental acute otitis media in the chinchilla, using an enzyme-linked immunosorbent assay. During acute otitis media, a reasonable antibody titer was observed: local antibody titers in the MEEs were equal to or greater than those of the serum samples for four of five MEE samples obtained at one week after inoculation. By two weeks, titers in both serum and MEE samples were increased significantly. However, the bacteria persisted in the middle ear cavity, even in the presence of increasing antibody titers, for up to five weeks after infection. The reason for this persistence of the bacteria in the middle ear is unknown.
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PMID:Antibody response in experimental Haemophilus influenzae otitis media. 351 2

We performed a randomized controlled trial of amoxicillin plus clavulanate versus cefaclor for treatment of acute otitis media. Total daily doses given in three divided doses were 40 mg/kg amoxicillin plus 10 mg/kg clavulanate, and 40 mg/kg cefaclor. Pathogens were eradicated from the middle ear exudate after 3 to 6 days of therapy in 35 (97%) of 36 patients given amoxicillin-clavulanate compared with 24 (75%) of 32 given cefaclor (P = 0.028). When analysis was restricted to patients with positive urine or serum drug assays during therapy, pathogens were eliminated in 33 (97%) of 34 patients given amoxicillin-clavulanate compared with 21 (75%) of 28 given cefaclor (P = 0.026). Bacterial isolates associated with bacteriologic failure of cefaclor therapy were Streptococcus pneumoniae (two patients), beta-lactamase-negative Haemophilus influenzae (four), and beta-lactamase-positive Branhamella catarrhalis (two). The single failure with amoxicillin-clavulanate therapy was associated with non-beta-lactamase-producing H. influenzae isolated from the middle ear exudate. We conclude that cefaclor is less efficacious than amoxicillin-clavulanate for the treatment of acute otitis media.
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PMID:A randomized controlled trial of amoxicillin plus clavulanate compared with cefaclor for treatment of acute otitis media. 353 3

The present investigation was conducted to find out if a relapse of acute purulent otitis media is associated with a decreased sensitivity of nasopharyngeal pathogens to commonly used antimicrobial agents. All but one of 63 children with relapse included in this study yielded one or more of the classical middle ear pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Branhamella catarrhalis, S. pyogenes) in their nasopharynx (NPH) secretions. S. pneumoniae was the predominating isolate from NPH (71% of the patients) as well as from middle ear effusion (53%). At a control visit 4 weeks after the start of antibiotic therapy, 91% were NPH carriers of potential pathogens and S. pneumoniae was still the most common isolate (53%). Beta-lactamase was produced by 55% of B. catarrhalis isolates from the NPH specimens on the first visit, but only by 33% of B. catarrhalis isolates on the control visit. Two NPH isolates of H. influenzae produced beta-lactamase. One isolate of S. pneumoniae (serotype 18) was intermediately sensitive to phenoxymethylpenicillin. Generally low MICs were found for erythromycin and cefaclor. H. influenzae isolates were generally sensitive to ampicillin in vitro, but only 1 isolate was fully sensitive to erythromycin. B. catarrhalis isolates were uniformly sensitive to doxycycline and trimethoprim/sulphamethoxazole. No tolerance to penicillin was demonstrated in S. pneumoniae and H. influenzae. The present data indicate that the relapse of acute otitis media is not associated with development of tolerance or resistance to therapeutic antimicrobials commonly used.
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PMID:Relapse of acute purulent otitis media: antibiotic sensitivities of nasopharyngeal pathogens. 361 95

We studied the concentration of ampicillin (ABPC) into middle ear effusions after administration of bacampicillin (BAPC). Nine patients with acute purulent otitis media were given orally single doses of the drug at a level of 10 mg/kg, and concentrations of ABPC which is the active antibiotic metabolite of BAPC were determined in middle ear effusions periodically after the administration. Bacteria present in effusions were identified, and their ability to produce beta-lactamase was also determined. ABPC concentrations in middle ear effusions were inversely related to the ability of bacteria detected from the intratympanic cavity to produce beta-lactamase. ABPC concentrations in middle ear effusions from which only beta-lactamase negative organisms were detected were higher by 5.2- and 2.3- fold at 60 and 120 minutes after the administration of BAPC, respectively, than those in effusions from which beta-lactamase positive organisms were detected. ABPC concentrations achieved in middle ear effusions in cases where only beta-lactamase negative organisms were detected exceeded MIC80's of the drug against main causative bacteria of acute purulent otitis media such as Streptococcus pneumoniae, Streptococcus pyogenes, and Haemophilus influenzae. Because only 10% or less of these species produces beta-lactamase, BAPC appears to be one of the highly effective drugs in the treatment of this disease.
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PMID:[A study of concentration of ampicillin into middle ear effusion after administration of bacampicillin]. 379 76

The total concentration of secretory IgA (SIgA) and secretory component (SC) as well as the occurrence of pathogen specific serum type (IgG, IgA and IgM) and secretory type antibodies against Streptococcus pneumoniae and Haemophilus influenzae in the middle ear effusion during an attack of otitis media were studied by using the ELISA method. The middle ear effusion samples were taken at 2 to 4 weeks' intervals from patients with recurrent acute otitis media (RAOM) or secretory otitis media (SOM). In the samples of the RAOM patients the SC/SIgA ratio was 2.2, while in the SOM samples the ratio was 13.6. Both serum and secretory type antibodies to the infecting bacteria could be detected in the middle ear effusions in both of the patient groups. The results of this study show that the middle ear can develop antigenic specific antibodies against the infecting bacteria. The increased production of SC seems to be related to the pathogenesis of SOM.
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PMID:Secretory IgA, secretory component and pathogen specific antibodies in the middle ear effusion during an attack of acute and secretory otitis media. 383 1


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