title: Antimicrobial resistance among respiratory pathogens collected in Thailand during 1999-2000.
abstract: A multi-center surveillance study was conducted in Thailand during 1999-2000 to determine antimicrobial susceptibilities among the respiratory pathogens Streptococcus pneumoniae (n = 206), Haemophilus influenzae (n = 305), and Moraxella catarrhalis (n = 39). Of the S. pneumoniae isolates collected, 33.5% were penicillin-susceptible, 27.2% intermediate and 39.3% resistant. Expectedly, resistance rates to beta-lactams were higher among penicillin-resistant (ceftriaxone, 14.8%; amoxicillin-clavulanate, 42.0%; cefuroxime, 100%) than penicillin-susceptible (ceftriaxone, 0%; amoxicillin-clavulanate, 0%; cefuroxime, 0%) isolates. Likewise, azithromycin and clarithromycin resistances were 4.3% and 5.8% among penicillin-susceptible isolates, and 77.8% and 95.1% among penicillin-resistant isolates. All S. pneumoniae remained susceptible to vancomycin and 99.5% were susceptible to levofloxacin. Multidrug resistance (resistance to >3 antimicrobial classes) was present in 25.2% of pneumococcal isolates (n = 52), with resistance to azithromycin, penicillin and trimethoprim-sulfamethoxazole the most common phenotype (40/52 isolates; 77.0%). Among the isolates of H. influenzae, the prevalence of beta-lactamase production was 45.2%. All isolates of H. influenzae were susceptible to amoxicillin-clavulanate, azithromycin, ceftriaxone, cefuroxime and levofloxacin while 49.5% were resistant to trimethoprim-sulfamethoxazole. All 39 isolates of M. catarrhalis produced beta-lactamase. Azithromycin (MIC90, < or = 0.03 microg/ml) and levofloxacin (MIC90, 0.03 microg/ml) were the most active agents tested against M. catarrhalis. The results of this study may serve as a baseline for future studies to monitor antimicrobial susceptibilities among respiratory pathogens in Thailand.
authors.affiliation: Focus Technologies, Inc, Herndon, Virginia 20171, USA. icritchley@focusanswers.com
authors.forename: I A
authors.initials: IA
authors.lastname: Critchley
authors.forename: R
authors.initials: R
authors.lastname: Blosser-Middleton
authors.forename: M E
authors.initials: ME
authors.lastname: Jones
authors.forename: J
authors.initials: J
authors.lastname: Yamakita
authors.forename: N
authors.initials: N
authors.lastname: Aswapokee
authors.forename: P
authors.initials: P
authors.lastname: Chayakul
authors.forename: P
authors.initials: P
authors.lastname: Tharavichitukul
authors.forename: A
authors.initials: A
authors.lastname: Vibhagool
authors.forename: C
authors.initials: C
authors.lastname: Thornsberry
authors.forename: J A
authors.initials: JA
authors.lastname: Karlowsky
authors.forename: D F
authors.initials: DF
authors.lastname: Sahm
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000187:drug effects* / Q000302:isolation & purification; D011159:Population Surveillance; D012141:Respiratory Tract Infections / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D013785:Thailand / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents