Antimicrobial resistance patterns and characterization of integrons in clinical isolates of Shigella from China.
One hundred fifty-three Shigella isolates were examined for multiple antibiotic resistance phenotypes and prevalence of class 1 and class 2 integron sequences. The gene cassettes dfrA17-aadA5, dfrA12-orfF-aadA2, and arr-3-aacA4 were found in typical class 1 integrons. The gene cassettes blaOXA-1-aadA1 and dfrA1-sat1-aadA1 were detected in atypical class 1 integrons and in class 2 integrons, respectively. This is the first report of arr-3-aacA4 cassette detected in typical class 1 integrons among Shigella isolates. Rates of antibiotic resistance were different between integron-positive and integron-negative strains (P < 0.05), and all integron-positive isolates were resistant to at least 3 different antimicrobial agents. Typical class 1 integron-positive isolates showed higher resistance rates to cefotaxime and ciprofloxacin than did integron-negative ones (P < 0.05). Typical class 1 integrons and β-lactamase genes were found in conjugative plasmids, otherwise class 2 and atypical class 1 integrons were located on chromosome. This study demonstrated the wide distribution of class 1 integrons in Shigella spp., which may lead resistance to cefotaxime and ciprofloxacin in China.
a Department of Infectious Diseases, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China.
Haifei
H
Yang
Yachao
Y
Pan
Lifen
L
Hu
Yanyan
Y
Liu
Ying
Y
Ye
Jun
J
Cheng
Jiabin
J
Li
D000293:Adolescent; D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004405:Dysentery, Bacillary / Q000382:microbiology; D016680:Genome, Bacterial / Q000235:genetics; D006801:Humans; D007223:Infant; D032023:Integrons / Q000235:genetics*; D008875:Middle Aged; D012760:Shigella / Q000187:drug effects / Q000235:genetics*; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics
D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases