Virulence characteristics and antimicrobial susceptibility of uropathogens from patients on Phuket Island, Thailand.

Urinary tract infection (UTI) is among the most common infections in human. Escherichia coli and Klebsiella pneumoniae are common uropathogens found to cause UTI. In this study, 113 F. coli and 52 K. pneumcniae isolates were collected from three hospitals on Phuket Island, Thailand. The majority of E. coli and K. pneumoniae isolates were from elderly females. Antimicrobial susceptibility testing demonstrated that most of F. coli isolates (77%) were resistant to tetracycline while cotrimoxazole was ranked second (65%) and nitrofurantoin was the least resistant (1%). K. pneumoniae isolates were also most resistant to tetracycline and cefotaxime (65%). The presence of extended spectrum-beta lactamase (ESBL) producers among E. coli isolates were 46% and 57% in K. pneumoniae. Twenty-seven E. coli isolates carried at least one of the common urovirulence genes (pap, afa, hlyA), the majority isolated from patients in the internal medicine ward. One rare K. ozaenae was isolated from a 45-year-old catheterized male patient from the orthopedics surgery ward. This isolate demonstrated resistance to all antimicrobial agents tested except imipenem. This study is the first of such kind conducted in southern Thailand and should be useful in treating UTI patients in this area of Thailand.

First report in Thailand of a stx-negative Escherichia Coli 0157 strain from a patient with diarrhea.

E. coli serotype 0157 is well known to cause serious illnesses in humans. However, there has been no case report to date of this serotype in Thailand. In this study, we report for the first time E. coli 0157 (designated as PSU120) isolated from a stool sample among 228 diarrheal swab samples at Hat Yai Hospital, Songkhla Province, Thailand. This PSU120 was identified as being stx-negative and lacked eae but carried escV, a marker for the locus of enterocyte effacement. Of the five reported integration sites frequently occupied by stx phages, the sbcB and yehV loci were occupied, suggesting that PSU120 is active in horizontal genetic transfer. Antimicrobial susceptibility assay revealed that E. coli 0157 strain PSU120 was resistant to cephalothin, erythromycin, methicillin and vancomycin. Using pulsed- field gel-electrophoresis to compare the genetic relatedness of E. coli 0157 strain PSU120 to two other E. coli 0157 strains, namely, the well-established EHEC strain EDL933 and PSU2, a surrogate of E. coli 0157:H7 whose genotype stx1-, stx2+, eae+ is frequently obtained from the environment in this area during the last decade, revealed 88.6% in similarity. We suggest that PSU120 was originally stx+ but lostthe gene after establishing infection.