Association of INF-gamma/A+874T gene polymorphisms with respiratory syncytial virus bronchiolitis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>A deficient interferon-gamma (IFN-gamma) response has been involved in the pathogenesis of severe respiratory syncytial virus (RSV) infection. Gene polymorphisms in IFN-gamma/A+874T have been associated with the susceptibility to asthma and might be related to disease severity of RSV infection. This study investigated the single nucleotide polymorphisms (SNPs) of IFN-gamma/A+874T in Han children in Wenzhou area and to explore the correlation between gene polymorphisms of IFN-gamma/A+874T and the susceptibility and disease severity of RSV bronchiolitis, as well as the effect of SNPs upon nasopharyngeal secretions (NPS) IFN-gamma and total serum IgE levels.</p><p><b>METHODS</b>One hundred and fourteen hospitalized children with RSV bronchiolitis and 90 healthy controls were recruited. Sequence analysis was used for detecting the SNPs of IFN-gamma/A+874T. NPS IFN-gamma levels were measured using ELISA. Total serum IgE levels were assayed using the chemiluminescence method.</p><p><b>RESULTS</b>IFN-gamma/A+874T gene polymorphisms were present in both the patient and the control groups. AA and AT genotypes were found in both groups, with a AA frequency of 82.5% vs 77.8% and a AT frequency of 17.5% vs 21.1% (p>0.05). The frequency of allele was 90.4% (A) and 9.6% (T) in the patient group, and 88.3% (A) and 11.7% (T) in the control group, respectively. There were no significant differences in the allele frequency between the two groups. Moreover, no difference was found both in NPS IFN-gamma and total serum IgE levels between AA and AT genotypes in the patient group. There were no significant differences in the variation of IFN-gamma/+874 between mild and moderate to severe cases.</p><p><b>CONCLUSIONS</b>IFN-gamma/A+874T gene polymorphisms were present in Han children in Wenzhou area. Gene variations were not associated with the susceptibility and disease severity of RSV bronchiolitis as well as IFN-gamma and total serum IgE levels.</p>

Detection of etiologic agents and antibiotic resistance in children with acute lower respiratory tract infection in Wenzhou City / 中国当代儿科杂志

<p><b>OBJECTIVE</b>The etiology of acute lower respiratory tract infection (LRTI) in children in Wenzhou City remains poorly defined. This study investigated the etiological agents responsible for acute LRTI and patterns of the antibiotic resistant bacterial pathogens in children with acute LRTI from Wenzhou City.</p><p><b>METHODS</b>Lower respiratory tract secretions were obtained from 454 children with acute LRTI (aged 1 month to 10 years, median age 6 months) within 24 hrs after admission for bacterial culture. Meanwhile respiratory viruses were detected by the Direct immunofluorescence (DIF) assay. The K-B method was applied for the drug susceptibility test.</p><p><b>RESULTS</b>Etiological agents were identified in 297 cases out of 454 patients (65.4%. Viral pathogens were identified in 229 cases (50.4%), bacteria in 135 cases (29.7%) and mixed viral-bacterial infections in 67 cases (14.8%). The isolating rate of Respiratory syncytial virus (RSV) was the highest (180 cases, 39.6%) in all of the samples. The isolating rates of other viral pathogens were as follows: Parainfluenza virus 3 type (PIV3) (6.6%), Adenovirus (2.2%), Influenza A (0.9%) and Influenza B (0.7%). Of the 135 strains of bacterial pathogens, 19 kinds of bacterial pathogens were isolated. The predominant isolate was Klebsiella pneumoniae (K. pneumoniae) (9.9%), followed by Escherichia coli (E.coli) (4.4%), Streptococcus pneumoniae (S. pneumoniae) (4.2%) and Staphylococcus aureus (S. aureus) (4.2%). The isolating rates of K. pneumoniae and E.coli with extended-spectrum beta-lactamases strains (ESBLs) positive were 42.2% and 65.0%, respectively. The pathogens isolated of the first 5 places in children with acute LRTI under six months were RSV, K. pneumoniae, PIV3, E.coli and S. aureus in turn. RSV, PIV3, S. pneumoniae, K. pneumoniae and E.coli were found to be the pathogens of the first 5 places in children with acute LRTI between six months and three years. The resistant rates of K. pneumoniae and E.coli to ampicillin were 97.8% and 75.0%, respectively. K. pneumoniae and E.coli with positive ESBLs were resistant to cephalosporin. The resistant rates of S. pneumoniae to erythromycin and penicilin were 100% and 68.4%, respectively. The resistant rates of S. aureus to erythromycin and penicillin were 94.7% and 89.5%, respectively.</p><p><b>CONCLUSIONS</b>RSV is the most common pathogen responsible for acute LRTI in children in Wenzhou City, followed by K. pneumoniae and PIV3. The rate of antibiotic resistance of common bacteria and the isolating rate of Gram-negative bacillus with ESBLs positive are high.</p>