title: Serotype distribution and beta-lactam resistance in Haemophilus influenzae isolated from patients with respiratory infections in Korea.
abstract: Haemophilus influenzae is a frequent causative bacterial pathogen of respiratory tract infections. Resistance to beta-lactam antibiotics has been a significant clinical problem in treatment for H. influenzae respiratory infections. This study describes the serotype, antibiotic resistance and distribution of TEM-1 or ROB-1 beta-lactamase in H. influenzae isolates from local private hospitals from 2002 to 2004. Among the 100 H. influenzae respiratory isolates, only 7% were identified as serotypes a, b, e, and f, with the remaining 93% being nontypeable. Resistance to ampicillin, cefaclor, and tetracycline was 57%, 46%, and 16%, respectively. All strains were susceptible to azithromycin and ciprofloxacin, whereas amoxicillin/clavulanate, cefotaxime, and imipenem exhibited reduced susceptibilities of 99%, 99%, and 91%, respectively. All 57 ampicillin-resistant strains (minimum inhibitory concentration, MIC>or=4 microg/ml) were beta-lactamase-positive and possessed the TEM-1 type beta-lactamase. One beta-lactamase-positive amoxicillin/clavulanate-resistant isolate that was resistant to ampicillin (MIC>128 microg/ml) had the TEM-1 type beta-lactamase and not susceptible to cefaclor and cefotaxime. Analysis of penicillin binding protein 3 revealed six residues (Asp-350, Met-377, Ala-502, Asn-526, Val-547, and Asn-569) that were substituted by Asn, Ile, Val, Lys, Ile, and Ser, respectively.
authors.affiliation: Division of Bacterial Respiratory Infections, Center for Infectious Diseases, National Institute of Health, Korea Centers for Disease Control and Prevention, Seoul, Republic of Korea, songmee@hanmail.net
authors.forename: Songmee
authors.initials: S
authors.lastname: Bae
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Lee
authors.forename: Eunah
authors.initials: E
authors.lastname: Kim
authors.forename: Jaehwa
authors.initials: J
authors.lastname: Lee
authors.forename: Jaeyon
authors.initials: J
authors.lastname: Yu
authors.forename: Yeonho
authors.initials: Y
authors.lastname: Kang
mesh_terms: D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D006192:Haemophilus Infections / Q000453:epidemiology / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D046915:Penicillin-Binding Proteins / Q000235:genetics; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology*; D012703:Serotyping; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D046915:Penicillin-Binding Proteins; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1; C477296:beta-lactamase bla(ROB-1), Haemophilus influenzae