Integron types, gene cassettes, antimicrobial resistance genes and plasmids of Shigella sonnei isolates from outbreaks and sporadic cases in Taiwan.
This study analysed the presence, location and transferability of integrons and antibiotic resistance genes in 103 Shigella sonnei outbreak isolates and in 32 sporadic isolates from Taiwan. Multiple antimicrobial resistance was common in both outbreak (95 %) and sporadic (97 %) isolates. Class 1 integrons were present in 34 outbreak isolates (33 %) and in six sporadic isolates (19 %). This study is the first, to our knowledge, to identify an atypical sul3-associated class 1 integron carrying the estX-psp-aadA2-cmlA-aadA1-qacH cassette array in Shigella. Class 2 integrons carrying the dfr1-sat2-aadA1 cassette array were predominant in outbreak isolates (90 %) but were not present in sporadic isolates. Other antimicrobial resistance genes not associated with integrons were found to encode resistance to ampicillin (bla(TEM)), chloramphenicol (cat1), sulfonamide (sul2) and tetracycline (tetA and tetB). The most common plasmid size was 130&emsp14;kb (observed in 43 and 97 % of 1998 outbreak and sporadic isolates, respectively). In conclusion, the plasmid location of resistance genes and horizontal plasmid transfer promote the spread of multiple resistance genes in outbreak and sporadic isolates of S. sonnei.
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.|Department of Microbiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.
Chung-Yu
CY
Chang
Department of Laboratory Medicine, Kaohsiung Medical University Hospital, 100 Tzyou 1st Road, Kaohsiung 807, Taiwan, ROC.|Department of Internal Medicine, Kaohsiung Medical University Hospital, 100 Tzyou 1st Road, Kaohsiung 807, Taiwan, ROC.|Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.
Po-Liang
PL
Lu
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.|Department of Microbiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.
Chung-Che
CC
Lin
Department of Food Science and Technology, Tajen University, 20 Weisin Road, Sin-er Village, Yanpu Township, Pingtung County 907, Taiwan, ROC.
Tsong-Ming
TM
Lee
Department of Microbiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.
Mei-Yin
MY
Tsai
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.|Department of Microbiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC.
Lin-Li
LL
Chang
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004269:DNA, Bacterial; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D004405:Dysentery, Bacillary / Q000453:epidemiology* / Q000382:microbiology*; D005798:Genes, Bacterial; D006801:Humans; D032023:Integrons; D008969:Molecular Sequence Data; D010957:Plasmids; D017422:Sequence Analysis, DNA; D012764:Shigella sonnei / Q000235:genetics* / Q000302:isolation & purification; D013624:Taiwan / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial