Prevalence of Haemophilus influenzae with resistant genes isolated from young children with acute lower respiratory tract infections in Nha Trang, Vietnam

• Published in: Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy Vol. 14; no. 5; pp. 349 - 353
• Main Authors: Gotoh, K, Qin, L, Watanabe, H, Watanabe, K, Anh, D.D, Huong, P.L.T, Anh, N.T.H, Cat, N.D.L, Ha, L.L, Ai, L.T.T, Tien, N.M, Minh, T.T, Oishi, K
• Format: Journal Article
• Language: English
• Published: Japan Elsevier Ltd 01.10.2008; Springer Japan
• Subjects: Acute Disease; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; beta-Lactamases - genetics; beta-Lactamases - metabolism; Child; Child, Preschool; Drug resistance; Drug Resistance, Bacterial - genetics; Electrophoresis, Gel, Pulsed-Field; Haemophilus Infections - drug therapy; Haemophilus Infections - epidemiology; Haemophilus influenzae; Haemophilus influenzae - drug effects; Haemophilus influenzae - genetics; Hematology, Oncology and Palliative Medicine; Humans; Infant; Infectious Diseases; Medical Microbiology; Medicine; Medicine & Public Health; Microbial Sensitivity Tests; Nasopharynx - microbiology; Original Article; Prevalence; Pulsed-field gel electrophoresis (PFGE); Respiratory Tract Infections - drug therapy; Respiratory Tract Infections - epidemiology; Vietnam - epidemiology; Virology; Vietnam; Pulsed-field gel electrophoresis (PFGE); Drug resistance; Child; Haemophilus influenzae
• ISSN: 1341-321X; 1437-7780
• DOI: 10.1007/s10156-008-0632-1

Abstract Our study was undertaken to investigate the characteristics of Haemophilus influenzae in young children with acute lower respiratory tract infections in Nha Trang, Vietnam. The study population consisted of 116 children less than 5 years of age admitted to Khanh Hoa General Hospital due to acute lower respiratory tract infections between July 2004 and April 2005. Organisms could be detected from nasopharyngeal swabs (NP) in 72 (62.1%) of the 116 children. Haemophilus influenzae was the most common organism, and 39 strains were isolated from 39 children aged 2 to 60 months (mean age, 16 months). We examined 37 of these 39 H. influenzae strains. The serotypes of the 37 isolates were all nontypeable, and 22 strains (59.5%) were β-lactamase producing. Polymerase chain reaction (PCR) analysis to identify resistance genes revealed that 17 strains had the TEM-1-type β-lactamase gene alone, 6 strains had the ftsI gene with the same substitution as that in g low-β-lactamase-negative ampicillin-resistant (g low-BLNAR) strains, and 6 strains had both the TEM-1-type β-lactamase gene and the ftsI gene with the same substitution as that in g β-lactamase-producing amoxicillin clavulanic acid-resistant (g BLPACR I) strains, although no BLNAR strains were found. Molecular typing by pulsed-field gel electrophoresis (PFGE) showed that the 6 g low-BLNAR strains had five PFGE patterns and the 6 g BLPACR I strains had four PFGE patterns. Our results indicate that BLNAR strains are still not prevalent, but that g low-BLNAR and g BLPACR I strains are potentially spreading in Nha Trang, Vietnam.