Prevalence and characteristics of fecal antimicrobial-resistant Escherichia coli in a cohort of Japanese men undergoing prostate biopsy

ObjectivesTo examine resistant Escherichia coli in rectal swab culture of Japanese men undergoing prostate biopsy, and to determine its prevalence, genotypic characteristics and carriage risk factors. MethodsRectal swabs of consecutive men undergoing transrectal ultrasound-guided prostate biopsy from April 2013 to March 2015 were cultured to isolate fluoroquinolone-resistant and extended-spectrum -lactamase-producing E. coli. The prevalence and antimicrobial susceptibility of these resistant E. coli strains and extended-spectrum -lactamase genotyping were examined. The risk factors of antimicrobial resistance carriage were also examined. ResultsThe cohort was 376 men with a mean age of 67.8 years. Fluoroquinolone-resistant E. coli and extended-spectrum -lactamase-producing E. coli were detected in 37 men (9.8%) and 22 men (5.9%), respectively, with fluoroquinolone-resistant and/or extended-spectrum -lactamase-producing E. coli in 48 men (13.0%). All 49 antimicrobial-resistant strains were susceptible to tazobactam/piperacillin, amikacin, fosfomycin, meropenem and faropenem. CTX-M-9 and CTX-M-1 group were detected in 14 (63.6%) and eight (36.4%) men, respectively. CTX-M-9 showed relatively higher susceptibility to LVFX and minocycline compared with CTX-M-1. Diabetes mellitus was a significant factor for carriage of resistance by multivariate analysis (odds ratio 2.12, P = 0.039). ConclusionsThe present study showed the fecal carriage of fluoroquinolone-resistant E. coli and extended-spectrum -lactamase-producing E. coli at 9.8% and 5.9%, respectively, with CTX-M-9 group of extended-spectrum -lactamase-producing E. coli comprising 63.6%, in Japanese men receiving prostate biopsy. The carriage of fluoroquinolone-resistant and/or extended-spectrum -lactamase-producing E. coli was significantly related to diabetes.