High prevalence of nasal carriage of β-lactamase-negative ampicillin-resistant Haemophilus influenzae in healthy children in Korea

• Published in: Epidemiology and infection 2013-03, Vol.141 (3), p.481-489
• Main Authors: BAE, S. M., LEE, J. H., LEE, S. K., YU, J. Y., LEE, S. H., KANG, Y. H.
• Format: Article
• Language: English
• Subjects: Amoxicillin; Amoxicillin-Potassium Clavulanate Combination - pharmacology; Ampicillin - pharmacology; Ampicillin Resistance - genetics; Anti-Bacterial Agents - pharmacology; Antibiotics; Antimicrobials; Bacteriology; beta-Lactamases - genetics; beta-Lactamases - metabolism; Biological and medical sciences; Carrier State - epidemiology; Carrier State - microbiology; Child; Child, Preschool; Children; Elementary schools; Epidemiological Monitoring; Fundamental and applied biological sciences. Psychology; Genotype; Haemophilus influenzae; Haemophilus influenzae - drug effects; Haemophilus influenzae - enzymology; Haemophilus influenzae - genetics; Humans; Infectious diseases; Kindergarten education; Microbial colonization; Microbial Sensitivity Tests; Microbiology; Miscellaneous; Nose - microbiology; Original Papers; Other Bacterial infections; Preschool children; Prevalence; Republic of Korea - epidemiology; Respiratory tract infections
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268812001082

This study investigated the carriage of antimicrobial resistant Haemophilus influenzae in 582 healthy children attending kindergarten or elementary school at four intervals over a 9-month period in Seoul, Korea. Diverse colonization patterns and a lower level of long-term persistent carriage by H. influenzae status were evident in this study. Colonizing H. influenzae isolates showed a high rate of resistance to β-lactams including ampicillin (51·9%), cefaclor (52·1%), and amoxicillin/clavulanate (16·3%). Based on the ampicillin resistance mechanism, H. influenzae isolates were categorized as β-lactamase-negative, ampicillin-susceptible (BLNAS) (48·1%), β-lactamase-positive, ampicillin-resistant (BLPAR) (22·6%), β-lactamase-negative, ampicillin-resistant (BLNAR) (22·8%), and β-lactamase-positive, amoxicillin/clavulanate-resistant (BLPACR) strains (6·5%). This study provides the first evidence of a high prevalence (22·8%) of BLNAR strains of H. influenzae nasal carriage in healthy children attending kindergarten or the first 2 years of elementary school in Korea. The high carriage of these resistant strains in overcrowded urban settings may create reservoirs for development of H. influenzae-resistant strains.