molecular detection of antibiotic resistance genes among enterococcus faecalis isolated from fecal and urine samples of patients with community-acquired urinary tract infections

conclusions the simultaneous detection of e. faecalis in a patient’s gastrointestinal and urine tracts can indicate the presence of uropathogenic enterococcus. further study is essential to identify virulence factors involved in the colonization of these isolates in the urinary tract. background urinary tract infection (uti) is one of the most common bacterial infections in outpatient settings. enterococcus species is currently considered the second most common cause of uti. objectives the aim of this study was to investigate antibiotic resistance patterns among enterococcus faecalis strains and evaluate the association of antibiogram patterns from urine and fecal samples in community-acquired utis using phenotypic and molecular methods. materials and methods a total of 144 urine and fecal samples were obtained from outpatients with uti who had been referred to labbafinejad hospital and milad hospital from august 2014 to april 2015. for bacteriological study, samples were cultured in enterococcosel and blood agar. antimicrobial susceptibility tests were evaluated using the disk diffusion method and the e. test according to criteria recommended by the clinical and laboratory standards institute (clsi). pcr was performed for the detection of specific species and the antibiotic resistance genes tetm and vana. results of the 72 e. faecalis strains isolated from urine samples, 63 (87.5%) were also isolated from fecal samples. 40 (63.4%) of the isolates found in both urine and feces had similar antibiotic sensitivity patterns. 17 (26.9%) of the isolates found in both specimens were different in a class of antibiotic (related) and 8 (12.6%) isolates in more than one or two class of antibiotics (difference). the results of the disk diffusion methods were analyzed according to clsi breakpoints. the antibiotic resistance of strains isolated from urine samples was evaluated for tetracycline (65 strains [90.3%] resistant), minocycline (64 [88.9%]), gentamicin (120 µg) (21 [29.2%]), ciprofloxacin (17 [23.6%]), levofloxacin (12 [16.7%]), and gatifloxacin (11 [15.3%]). the same evaluation was conducted for the strains isolated from fecal samples for tetracycline (48 [76.1%]), minocycline (45 [71.4%]), gentamicin (10 [15.8%]), ciprofloxacin (8 [12.6%]), and gatifloxacin (4 [6.3%]). all strains were sensitive to vancomycin, ampicillin, penicillin, nitrofurantoin, linezolid, and daptomycin. according to the pcr results as a gold standard and molecular method, 67 (93%) of the isolates from urine and 52 (82.5%) of the isolates from feces were positive for tetm genes. the vana gene was not found in any strain.