title: Prevalence of β-lactamase-negative ampicillin-resistant haemophilus influenzae isolated from patients of a teaching hospital in Thailand.
abstract: The aim of this study was to investigate the prevalence of β-lactamase-negative  ampicillin-resistant (BLNAR) Haemophilus influenzae isolated from patients of a teaching hospital  in Thailand. Eighty-eight isolates of H. influenzae were collected between September 2005 and March  2008. All isolates were identified and characterized for biotypes and capsular types. The  β-lactamase production of these isolates was examined, and their susceptibility to the following  12 antimicrobial agents was determined: ampicillin (AMP), amoxicillin-clavulanate (AMC), cefotaxime  (CTX), cefuroxime (CXM), meropenem (MEM), clarithromycin (CLR), telithromycin (TEL), tetracycline  (TET), ciprofloxacin (CIP), levofloxacin (LEV), trimethoprim-sulfamethoxazole (SXT), and  chloramphenicol (CHL). Of the 88 H. influenzae isolates, 69 (78.4%), 13 (14.8%), 4 (4.5%), and 2  (2.3%) were from the respiratory tract, pus, the genital tract, and blood, respectively. Half of  the isolates were biotype II (44 isolates, 50%). The other half comprised biotypes I (23 isolates,  26.1%), III (15 isolates, 17.1%), and IV (6 isolates, 6.8%). All isolates were capsular  non-typeable, except for 2 isolates that were type f. Antimicrobial susceptibility showed that all  isolates were susceptible to AMC, CTX, MEM, TEL, CIP, and LEV (100%), whereas 96.6%, 94.3%, 80.7%,  68.2%, 50.0%, and 44.3% were susceptible to CXM, CLR, CHL, TET, AMP, and SXT, respectively. The  β-lactamase-production rate of H. influenzae isolates was 40.9%, and the prevalence of BLNAR was  18.2%.
authors.affiliation: Centre for Research and Development of Medical Diagnostic Laboratories, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand. arolul＠kku.ac.th
authors.forename: Aroonlug
authors.initials: A
authors.lastname: Lulitanond
authors.forename: Aroonwadee
authors.initials: A
authors.lastname: Chanawong
authors.forename: Keskaew
authors.initials: K
authors.lastname: Pienthaweechai
authors.forename: Pipat
authors.initials: P
authors.lastname: Sribenjalux
authors.forename: Ratree
authors.initials: R
authors.lastname: Tavichakorntrakool
authors.forename: Chotechana
authors.initials: C
authors.lastname: Wilailuckana
authors.forename: Pirom
authors.initials: P
authors.lastname: Puang-Ngern
authors.forename: Pairshompoo
authors.initials: P
authors.lastname: Saetung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000668:Ampicillin Resistance; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D005260:Female; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000145:classification / Q000187:drug effects* / Q000201:enzymology* / Q000302:isolation & purification; D006784:Hospitals, Teaching; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015995:Prevalence; D012703:Serotyping; D013785:Thailand / Q000453:epidemiology; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases