Antimicrobial susceptibility and genetic characteristics of Haemophilus influenzae isolated from community-acquired respiratory tract infection patients in Shanghai City, China.
Haemophilus influenzae is an important causative pathogen of community-acquired respiratory infection in China. In this study we investigated 37 H. influenzae strains isolated from patients with community-acquired respiratory tract infections (CARTI) in Shanghai city between Dec 2008 and Apr 2009. H. influenzae clinical isolates were identified, and b-lactamase production tests were conducted and minimal inhibitory concentrations(MIC) were measured. Pulsed-field gel electrophoresis(PFGE) was introduced as an effective finger printing method. Two isolates (5.4%) were verified as serotype b strains, and 30 strains (81.1%) were nontypeable H. influenzae. Furthermore, 10 (27.0%) were b-lactamase-producing ampicillin-resistance (BLPAR) (TEM-1 type)strains, 11 (29.8%) were low-b-lactamase-nonproducing ampicillin-resistant H. influenzae (Low-BLNAR) strains,and the rest were b-lactamase-negative ampicillin-susceptible(BLNAS) strains. Minimum inhibitory concentrations(MIC90; lg/ml) were 2 for ampicillin/sulbactam, 0.05 force fotaxime, 16 for cefaclor, 2 for azithromycin, 0.12 for levofloxacin, and 4 for imipenem. Fingerprint typing by PFGE revealed 23 independent patterns for the isolates. Pattern A (defined in this study) was predominant in BLPAR strains, and a variety of other patterns were detected in Low-BLNAR and BLNAS strains. Although the incidence of ampicillin resistant H. influenzae is increasing in CARTI patients in China, current antimicrobial chemotherapy seems to be effective.
Division of Infectious Diseases, Department of InfectiousMedicine, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, Fukuoka 830-0011, Japan. shin_ryou@med.kurume-u.ac.jp
Liang
L
Qin
Zhaoyan
Z
Zhou
Bijie
B
Hu
Taro
T
Yamamoto
Hiroshi
H
Watanabe
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002681:China / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006192:Haemophilus Infections / Q000453:epidemiology / Q000382:microbiology*; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012141:Respiratory Tract Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology*; D055815:Young Adult; D018440:beta-Lactam Resistance
D000900:Anti-Bacterial Agents