Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adherence of non-typable Haemophilus influenzae to respiratory epithelium was evaluated in a cotton rat model of respiratory syncytial virus (RSV) infection. Colonization with non-typable H. influenzae increased to a maximum within 4 days of RSV infection compared to RSV negative controls (4.58 +/- 0.17 vs 3.82 +/- 0.23 log colony forming units (CFU) per ml, P less than 0.05) and then declined over the subsequent 10 days (2.0 +/- 0 vs 3.78 +/- 0.39 CFU per ml, P less than 0.0001). In a second series of experiments, attachment of non-typable H. influenzae to epithelial cells collected from RSV infected cotton rats at the time of maximum virus replication was not different from controls (57.4 +/- 18.3 vs 52.0 +/- 24.3 bacteria per 50 cells). Systemic immunity to non-typable H. influenzae as measured by IgG-specific antibody to the outer membrane complex and bactericidal antibody did not influence colonization. These data suggest that colonization with non-typable H. influenzae is significantly affected by a concurrent infection with RSV; however, the site of bacterial attachment is not known.
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PMID:Effect of respiratory syncytial virus on adherence, colonization and immunity of non-typable Haemophilus influenzae: implications for otitis media. 159 48

Nasopharyngeal secretions and throat-swab specimens from 809 children less than 6 years old with acute respiratory infection were examined by culture and indirect immunofluorescence for the presence of virus or viral antigen. Blood was cultured for the presence of bacteria in selected cases of lower respiratory infection (LRI); pleural fluid also was cultured in cases of empyema. Viruses were detected in 163 (49%) of 331 children with LRI. Respiratory syncytial virus (RSV) was the commonest agent isolated (106 children). Other viruses isolated included parainfluenza viruses (36 children), adenoviruses (12), and influenza viruses (five). Outbreaks of infection due to RSV occurred during August through October. Pneumonia was the commonest LRI encountered (178 children). Among children with pneumonia, viruses were detected in 65 (37%) of 178 children, and bacteria were isolated from 27 (18%) of the 147 children for whom blood cultures were done. Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus were the common bacterial pathogens isolated. In cases of empyema and pyopneumothorax, S. aureus was the commonest organism isolated. There were 116 children with bronchiolitis, 83 (72%) of whom had viral infections; the majority of these children (81%) had RSV infection. Croup was uncommon (eight cases) and was caused mainly by parainfluenza viruses.
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PMID:Etiology of acute respiratory infections in children in tropical southern India. 186 77

Secondary bacterial infection was studied on 231 children admitted with Respiratory Syncytial virus (RSV) infection in the 10 years since 1987. Of the 231 children, 56 (24.2%) had dual bacterial infection possibly due to secondary bacterial invasion. The diagnoses of bacterial disease were sepsis (2), pyothorax (2), pneumonias (41), otitis media (7), nasopharyngitis (2) and urinary tract infection (2). Dual bacterial infections were more frequent in infants and children over 6 months than in infants younger than 6 months. The main etiologic agents were Staphylococcus aureus and enteric gram-negatives in infants, and Haemophilus influenzae, Streptococcus pneumoniae, beta streptococci and Branhamella catarrhalis in children over 1 year. The incidence of secondary bacterial infection was compared according to the usage of antibiotics just before admission. Patients who had been administered with penicillins or macrolides before admission had a significantly higher percentage of secondary bacterial infection (21/56, 37.5%) than those of no previous antibiotic therapy (11/64, 17.2%, p less than 0.025). The results indicate that the RSV infection itself sometimes predisposes to secondary bacterial infections, but indiscriminate use of antibiotics further increases the risk of secondary bacterial infections.
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PMID:[Clinical studies on the secondary bacterial infection in respiratory syncytial virus infection of children]. 250 38

Clinical and bacterial findings were prospectively studied in 90 children hospitalized because of middle or lower respiratory tract infection caused by respiratory syncytial virus (RSV) during a surveillance period of 12 months. The results were compared with those of RSV-negative children hospitalized with identical indications during the 3 peak months of the RSV epidemic (N = 91) or for the 3 months after the outbreak (N = 99). A high frequency of pneumonia and acute otitis media were found in both RSV-positive and RSV-negative children during the epidemic, but not in control patients after the epidemic. Bacterial infection, based on a significant rise of antibody titer and/or on detection of pneumococcal antigen in serum or urine, was observed in 39% of the children with RSV infection. The respective figures were 24% in RSV-negative children hospitalized during the epidemic and 8% after the epidemic. Our observations stress the role of RSV as a predisposing agent for secondary bacterial infection in the airways of children. The most common bacteria involved in the mixed RSV-bacterial infections were Streptococcus pneumoniae and Haemophilus influenzae, the latter being found only in pneumonic patients. The presence or absence of pneumonia or acute otitis media was not significantly correlated with evidence of pneumococcal infection. We conclude that a bacterial pathogen should be actively sought when managing patients with lower respiratory tract syndromes, especially in those who have evidence of RSV infection.
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PMID:Bacterial coinfection in children hospitalized with respiratory syncytial virus infections. 281 13

Viral and bacterial antigen and antibody assays were prospectively applied to study the microbial aetiology of community-acquired pneumonia in 195 hospitalised children during a surveillance period of 12 months. A viral infection alone was indicated in 37 (19%), a bacterial infection alone in 30 (15%) and a mixed viral-bacterial infection in 32 (16%) patients. Thus, 46% of the 69 patients with viral infection and 52% of the 62 patients with bacterial infection had a mixed viral and bacterial aetiology. Respiratory syncytial virus (RSV) was identified in 52 patients and Streptococcus pneumoniae in 41 patients. The next common agents in order were non-classified Haemophilus influenzae (17 cases), adenoviruses (10 cases) and Chlamydia species (8 cases). The diagnosis of an RSV infection was based on detecting viral antigen in nasopharyngeal secretions in 79% of the cases. Pneumococcal infections were in most cases identified by antibody assays; in 39% they were indicated by demonstrating pneumococcal antigen in acute phase serum. An alveolar infiltrate was present in 53 (27%) and an interstitial infiltrate in 108 (55%) of the 195 patients. The remaining 34 patients had probable pneumonia. C-reactive protein (CRP), erythrocyte sedimentation rate and total white blood cell count were elevated in 25%, 40% and 36% of the patients, respectively. CRP was more often elevated in patients with bacterial infection alone than in those with viral or mixed viral-bacterial infections. No other correlation was seen between the radiological or laboratory findings and serologically identified viral, bacterial or mixed viral-bacterial infections.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Aetiology of community-acquired pneumonia in children treated in hospital. 912 28

Respiratory syncytial virus (RSV) is a well-recognized cause of lower respiratory tract infections during early childhood in industrialized countries. The study of 4 RSV infection outbreaks which occurred during 1993-96 in The Gambia led to the identification of RSV infection in 574 children through the immunofluorescent staining of nasopharyngeal aspirate samples among children of median age 3-8 months who presented with respiratory infections at 3 hospitals in the Western region of the country. 13 children had conditions thought to increase the risk of severe RSV infection, with crepitations heard during physical examinations in 80% of children admitted to the hospital and wheezes heard in 39%. 80 children were given oxygen because of hypoxemia. 9 of 255 blood cultures were positive for the following pathogens: 4 Streptococcus pneumoniae, 2 Haemophilus influenzae type b, 2 Staphylococcus aureus, and 1 Enterobacter agglomerans. 13 children died. 90% of isolates typed during year 1 were RSV subgroup A, 25% in the second year of study, 75% in year 3, and 95% in year 4. These findings demonstrate that RSV is a significant cause of lower respiratory tract infection in young children in The Gambia, causing epidemics of bronchiolitis. It is most likely cost-effective to prevent RSV infection through vaccination.
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PMID:The clinical spectrum of respiratory syncytial virus disease in The Gambia. 953 50

Respiratory syncytial virus (RSV) infection is known to predispose children to otitis media and sinusitis due to bacteria such as nontypeable Haemophilus influenzae (NTHI). In this study, we investigated the role of NTHI surface outer membrane protein P5-homologous fimbriae (P5-fimbriae) in attachment to RSV-exposed A549 epithelial cells. Analysis by fluorescence flow cytometry showed that a live P5-fimbriated NTHI strain (NTHIF+) attached to a higher proportion of RSV-exposed A549 cells than to control cells (mean, 68% for RSV versus 29% for control; P = 0.008), while attachment of the P5-fimbriae-deficient isogenic mutant strain (NTHIF-) was significantly lower than in control cells and rose only slightly following RSV exposure (mean, 17% for RSV versus 10% for control, P = 0.229). Attachment of NTHIF+ did not correlate with the amount of RSV antigen expressed by A549 cells. Furthermore, paraformaldehyde-fixed NTHIF+ also demonstrated an enhanced binding to RSV-exposed cells. Observations by transmission electronic microscopy showed that the mean number of bacteria attached per 100 RSV-exposed A549 cells was higher for NTHIF+ than NTHIF- (99 versus 18; P < 0.001). No intracellular bacteria were identified. UV-irradiated conditioned supernatants collected from RSV-infected A549 cultures (UV-cRSV) also enhanced the attachment of NTHIF+ to A549, suggesting the presence of a preformed soluble mediator(s) in UV-cRSV that enhances the expression of receptors for P5-fimbriae on A549 cells. In summary, RSV infection significantly enhances NTHI attachment to respiratory epithelial cells. P5-fimbria is the critical appendage of NTHI that participates in this attachment. In clinical settings, blocking of the P5-fimbria-mediated attachment of NTHIF+ by passive or active immunity may reduce the morbidity due to NTHI during RSV infection.
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PMID:Fimbria-mediated enhanced attachment of nontypeable Haemophilus influenzae to respiratory syncytial virus-infected respiratory epithelial cells. 986 14

Non-typable Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and respiratory syncytial virus (RSV) are commonly isolated from patients during the course of chronic obstructive pulmonary disease (COPD). Earlier studies found that virus infection enhanced binding of bacterial respiratory pathogens to epithelial cells in vitro. The objective of the present study was to assess the effect of RSV infection of a human monocytic cell line on bactericidal activity and cytokine production in response to these bacterial respiratory pathogens. The effect of RSV infection on binding, uptake and intracellular killing of bacteria by a human monocytic leukaemia cell line, THP-1, was assessed. Cell culture supernates were examined with a mouse fibroblast cell assay for tumour necrosis factor-alpha (TNF-alpha) bioactivity. Expression of CD14, CD11a, CD18, CD15 and CD29 on uninfected and RSV-infected THP-1 cells was assessed by flow cytometry in relation to differences in bacterial binding. RSV infection of THP-1 cells significantly decreased their ability to bind and kill bacteria. Compared with uninfected cells, fewer bacteria bound to RSV-infected THP-1 cells and the surface antigens that have been reported to bind bacteria were expressed at lower levels on RSV-infected cells. RSV-infected cells incubated with bacteria exhibited less TNF-alpha bioactivity than uninfected cell incubated with bacteria. The results elucidate some of the mechanisms involved in the increased susceptibility of virus-infected patients to secondary bacterial infection. Reduced bacterial killing by virus-infected monocytes might contribute to reduced clearance of bacteria from the respiratory tract and damage elicited by the bacteria or cytokine response in COPD patients.
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PMID:Bactericidal activity of a monocytic cell line (THP-1) against common respiratory tract bacterial pathogens is depressed after infection with respiratory syncytial virus. 1070 42

We investigated the etiology of acute lower respiratory infection (ALRI) in children under 5 admitted to Srinagarind Hospital. The causative bacteria and viruses were determined by hemoculture and viral isolation from blood and nasopharyngeal aspirate samples. Antigens of respiratory syncytial virus (RSV) and Chlamydia trachomatis were detected using EIA. The 74 children less than 5 years of age with ALRI enrolled in our study were diagnosed with pneumonia (75.7%), croup (16.2%), and bronchiolitis (8.1%), respectively. Examination of blood or nasopharyngeal aspirate revealed viral or bacterial infections in 26 and 22 cases, respectively, whereas 5 of the children aged under 1 year (10%) were diagnosed with pneumonia caused by Chlamydia trachomatis. RSV was the most common virus detected (24.3%) and was associated with pneumonia and bronchiolitis, while the parainfluenza virus was the primary cause of croup. In cases of pneumonia, bacterial infections were identified in almost all of the cases: and Streptococcus pneumoniae and Haemophilus influenzae were the most commonly isolated (at 8.9% each). Mixed infections were detected in 8 cases (10.8%). The incidence of RSV infection peaked during the especially warm and cool seasons, whereas the bacterial infections were primarily associated with the relatively cool season. Our study indicates that a combined pneumococcal and Hib vaccine and a RSV vaccine would reduce the high rate of pneumonia in children under 5 years of age in Northeast Thailand.
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PMID:Etiology of acute lower respiratory tract infection in children at Srinagarind Hospital, Khon Kaen, Thailand. 1194 9

The present study was performed to elucidate the clinical outcome, and etiology of acute otitis media (AOM) in children based on virologic and bacteriologic tests. The study group consisted of 120 children aged 6 to 144 months with AOM. Middle ear fluid (MEF) was tested for viral pathogens by reverse transcriptase polymerase chain reaction (RT-PCR) and for bacteria by gram-staining and culture. Clinical response was assessed on day 2 to 4, 11 to 13, 26 to 28. Respiratory viruses were isolated in 39 patients (32.5%). Respiratory syncytial virus (RSV) (46.5%) was the most common virus identified in MEF samples, followed by human rhinovirus (HRV) (25.6%), human coronavirus (HCV) (11.6%), influenza (IV) type A (9.3%), adenovirus type sub type A (AV) (4%), and parainfluenza (PIV) type -3 (2%) by RT-PCR. In total 69 bacterial species were isolated from 65 (54.8%) of 120 patients. Streptococcus pneumoniae (S. pneumoniae) was the most frequently isolated bacteria. Viral RNA was detected in 31 (56.3%) of 55 bacteria-negative specimens and in 8 (12.3%) of 65 bacteria-positive MEF samples. No significant differences were found between children representing viral infection alone, combined viral and bacterial infection, bacterial infection alone, and neither viral nor bacterial infection, regarding clinical cure, relapse and reinfection rates. A significantly higher rate of secretory otitis media (SOM) was observed in alone or combined RSV infection with S. pneumonia or Haemophilus influenzae (H. influenzae) than in other viruses infection. Conclusion. This study provides information about etiologic agents and diagnosis of AOM in Turkish children. The findings highlight the importance of common respiratory viruses and bacterial pathogens, particularly RSV, HRV, S. pneumoniae and H. influenzae, in predisposing to and causing AOM in children.
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PMID:Acute otitis media and respiratory viruses. 1696 96


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