[Serotype distribution and drug resistance of Streptococcus pneumoniae , Haemophilus influenzae and Moraxella catarrhalis isolated from nasopharynx of Uygur children].

Objective: To investigate the serotype distribution and antimicrobial susceptibility pattern of Streptococcus pneumoniae ( S. pneumoniae ), Haemophilus influenzae ( H. influenzae ) and Moraxella catarrhalis ( M. catarrhalis ) isolates collected from nasopharyngeal swabs from Uygur children in Kashi. Methods: Nasopharyngeal swabs were collected from inpatient Uygur children aged from 1 month to 5 years with respiratory infections from the pediatric department, the First People's Hospital of Kashi, Xinjiang Uygur Autonomous Region. Antimicrobial susceptibilities of the isolates were determined with E-test and KB disk diffusion methods. The production of β-lactamase was detected for H. influenzae and M. catarrhalis isolates using nitrocefin disc method. Quellung test and latex agglutination test were adopted to identify serotypes of S. pneumoniae and H. influenzae isolates. Results: Forty-seven S. pneumoniae, 13 H. influenzae and 16 M. catarrhalis isolates were detected. All of the 47 S. pneumoniae isolates were sensitive to parenteral penicillin, amoxicillin-clavulanic acid, vancomycin and levofloxacin; the susceptibility rates to cefotaxime, imipenem and chloramphenicol were 94% (44/47), 89% (42/47), and 98% (46/47). The resistance rate to erythromycin was 74% (35/47). The most common serotype of S. pneumoniae was serotype 19A (10 strains, 21%). The coverage rate of 13-valent conjugate vaccine (PCV13) was 70% (33/47). None of the 13 H. influenzae isolates could be typed. They were highly susceptible to tested β-lactams antibiotics, except ampicillin. Only one H. influenzae isolate could produce β-lactamase, and two isolates were identified as β-lactamase-negative-ampicillin-resistant ones. The sixteen M. catarrhalis isolates were all positive in β-lactamase detection, but sensitive to amoxicillin-clavulanic acid, cephalosporins and meropenem. Conclusions: In Kashi, Xinjiang Uygur Autonmous Region, S. pneumoniae isolates from Uygur children were highly sensitive to parenteral penicillin and other β-lactams antibiotics. H. influenzae isolates from Uygur children were highly susceptible to amoxicillin-clavulanic acid, cephalosporins and ciprofloxacin. All M. catarrhalis isolates from Uygur children could produce β-lactamase, but were sensitive to the enzyme inhibitors and cephalosporins.