Acute Escherichia coli prostatitis in previously health young men: bacterial virulence factors, antimicrobial resistance, and clinical outcomes.

OBJECTIVES: To investigate clinical outcomes, bacterial virulence factors, and antimicrobial resistance in E. coli from young men presenting with acute bacterial prostatitis.

METHODS: Initial E. coli isolates from previously healthy young men with no factors compromising urinary tract anatomy or function were tested for virulence-associated genes by polymerase chain reaction (PCR) assays, phylogenetic grouping by triplex polymerase PCR, and antibiotic resistance.

RESULTS: All 18 patients responded to treatment, including 2 who required long-term therapy. E. coli were allocated to phylogenetic groups B2 (13 strains) and D (5 strains). Prostatitis isolates belonged to clones mainly represented by extraintestinal pathogenic E. coli (ExPEC) and preferentially uropathogenic E. coli and displayed marked accumulation of virulence genes (hly, cdt1, clb, pap, sfa/foc, fyuA, iroN, kpsMT(II), and traT) characteristic of highly virulent ExPEC. All phylogenetic group B2 strains coded for at least 1 toxin with carcinogenic potential (Colibactin, cytolethal distending toxins, or cytotoxic necrotizing factor). In contrast to their accumulation of virulence-associated traits, prostatitis strains were sensitive to standard antibiotics.

CONCLUSIONS: The phylogenetic background and accumulation of an exceptional repertoire of extraintestinal pathogenic virulence-associated genes indicate that these E. coli strains belong to a highly virulent subset of uropathogenic variants. In contrast, antibiotic resistance was minimal in these E. coli strains from previously healthy, young outpatients.