Characterisation of antimicrobial resistance patterns and class 1 integrons among Escherichia coli and Salmonella enterica serovar Choleraesuis strains isolated from humans and swine in Taiwan.
Escherichia coli isolates from humans (n=110) and swine (n=61) and Salmonella enterica serovar Choleraesuis isolates (n=95) from swine in southern Taiwan were characterised for antimicrobial resistance patterns and class 1 integrons. All E. coli isolates and S. Choleraesuis isolates were multidrug resistant and demonstrated high resistance to beta-lactams, aminoglycosides, tetracycline, sulfonamides, spectinomycin, chloramphenicol and nalidixic acid. By polymerase chain reaction and DNA sequencing, 104 (61%) E. coli isolates and 31 (33%) S. Choleraesuis isolates were found to carry class 1 integrons. The gene cassette array dfrA12-orfF-aadA2 was the most prevalent (24%) among the human and swine E. coli isolates, whilst the gene cassette array dfrA12-orfF-aadA2-sul1 was the most prevalent (24%) among S. Choleraesuis strains. For E. coil isolates, all class 1 integrons were located on conjugated plasmids. Meanwhile, human and swine E. coli isolates carrying identical gene cassettes were genetically unrelated. Our results revealed that multidrug resistance and class 1 integrons were widely present in E. coli and S. Choleraesuis isolates obtained in Taiwan and that class 1 integrons might play an important role in contributing to the horizontal transfer of antimicrobial resistance.
Hsu
Shu-Chen
SC
Department of Food Science, National Chung-Hsing University, Taichung, Taiwan, Republic of China.
Chiu
Tsai-Hsin
TH
Pang
Jen-Chieh
JC
Hsuan-Yuan
Chao-Hsiu
CH
Chang
Gan-Nan
GN
Tsen
Hau-Yang
HY
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D032023:Integrons / Q000235:genetics*; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013552:Swine / Q000382:microbiology*; D013624:Taiwan
D000900:Anti-Bacterial Agents