Author(s)

Wen-Chung Chang¹, Chung-Jung Wu², Chuan-Shee Liu³, Yilin Tsai⁴, Jen-Jain Lee³, Yuting Hsiao³, Shu-Ling Chou³, Chih-Hao Sun³, Chishih Chu^4*

¹Dentistry Division, Chiayi Branch, Taichung Veterans General Hospital, Taichung.
²Internal Medicine Department, Chiayi Branch, Taichung Veterans General Hospital, Taichung.
³Medical Laboratory Division, Chiayi Branch, Taichung Veterans General Hospital, Taichung.
⁴Department of Microbiology, Immunology, and Biopharmaceutics, National Chiayi University, Chiayi.

Uropathogenic Escherichia coli is the common pathogen to cause urinary tract infections (UTIs) and have become multidrug-resistant (MDR) extended-spectrum β-lactamase (ESBL) producers. The differences in the antimicrobial susceptibility, 5 bla genes, 12 virulence genes of 87 clinical ESBL-producing E. coli isolates and genomic variations and sequence types of 18 recurrent and repeated isolates from 9 patients were investigated. The 87 MDR-ESBL isolates collected mainly from indwelling urinary catheters (IUCs) and UTIs were highly resistant to fluoroquinolones, with over 50% of the isolates being resistant to cefepime and piperacillin/tazobactam and a few being resistant to carbapenem. These isolates carried at least two of the five bla genes examined, with the highest prevalence (87.4%) found for bla_CTX-M (bla_CTX-M3-like and bla_CTX-M14-like), followed by bla_CMY-2 (80.5%) and bla_SHV (56.3%). The predominant virulence genes were the fimbriae gene fimH and the toxin genes cnf1 and hlyA in blood isolates and the capsule gene kpsMTII in UTI and blood isolates. Over 80% of the isolates carried yersiniabactin and aerobactin of siderophores. In 18 isolates, the fluoroquinolone-resistant ST131 isolate of pulsotypes I and II with bla_CTX-M-15 was clonally disseminated in the hospital. The genomic plasticity of these ST131 occurred mainly through the conjugative plasmids with differences in replicon types A/C, I1, FIA, FIB and Y, size and number. In conclusion, MDR ESBL-producing E. coli isolates differed in virulence genes of UPEC and antibiotic resistance associated with the sources. Plasmid acquisition and chromosomal variations increase the spread of fluoroquinolone-resistant UPEC ST131 worldwide.

E. coli, ESBL, Virulence Genes, Antimicrobial Resistance, MLST

Chang, W. , Wu, C. , Liu, C. , Tsai, Y. , Lee, J. , Hsiao, Y. , Chou, S. , Sun, C. and Chu, C. (2016) Clonal Dissemination of Genetically Diverse Fluoroquinolone-Resistant Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli ST131 in a Veterans Hospital in Southern Taiwan. Advances in Microbiology, 6, 590-601. doi: 10.4236/aim.2016.69059.