Susceptibility to β-lactams and quinolones of Enterobacteriaceae isolated from urinary tract infections in outpatients

Abstract

The antibiotic susceptibility profile was evaluated in 71 Enterobacteriaceae isolates obtained from outpatient urine cultures in July 2010 from two health institutions in Santa Fe, Argentina. The highest rates of antibiotic resistance were observed for ampicillin (AMP) (69%), trimethoprim/sulfamethoxazole (TMS) (33%), and ciprofloxacin (CIP) (25%). Meanwhile, 21% of the isolates were resistant to three or more tested antibiotics families. Thirty integron-containing bacteria (42.3%) were detected, and a strong association with TMS resistance was found. Third generation cephalosporin resistance was detected in only one Escherichia coli isolate, and it was characterized as a bla CMY-2 carrier. No plasmid-mediated quinolone resistance (PMQR) was found. Resistance to fluoroquinolone in the isolates was due to alterations in QRDR regions. Two mutations in GyrA (S83L, D87N) and one in ParC (S80I) were observed in all CIP-resistant E. coli. It was determined to be the main phylogenetic groups in E. coli isolates. Minimum Inhibitory Concentration (MIC) values against nalidixic acid (NAL), levofloxacin (LEV), and CIP were determined for 63 uropathogenic E. coli isolates as MIC50 of 4 μg/mL, 0.03125 μg/mL, and 0.03125 μg/mL, respectively, while the MIC90 values of the antibiotics were determined as 1024 μg/mL, 64 μg/mL, and 16 μg/mL, respectively. An association between the phylogenetic groups, A and B1 with fluoroquinolone resistance was observed. These results point to the importance of awareness of the potential risk associated with empirical treatment with both the families of antibiotics.

Community-acquired lower urinary tract infections: Etiology, antimicrobial resistance, and treatment results in female patients

“…Marchisio et al . [ 13 ] reported that 21% of the isolates were resistant to three or more tested antibiotics families. In a study involving high prevalence of multidrug-resistant Enterobacteriaceae isolated from outpatient urine samples, more than 90% of the urinary isolates were reported to be resistant to sulfonamides.…”

PMQR Determinants Expression in Gram-negative Uropathogens Clinically Isolated from Hospitalized Patients with Pyelonephritis in Kharkiv, Ukraine

“…According to Piekarska K et al 2015, PMQR determinants were present in 49 urinary isolates (22.8%), among which aac(6')-Ib-cr and proteins Qnr predominated (85.7% and 26.5%, respectively) [15]. But Marchisio M et al did not find any plasmid-mediated quinolone resistance determinants among Enterobacteriaceae isolated from urinary tract infections patients [23].…”

Molecular Detection of Plasmid Mediated Quinolone Resistant Genes in Uropathogenic E. coli from Tertiary Referral Hospital in Tehran Iran

“…Interestingly, qnrB has been detected on the CTX-M-15 and SHV-12 ESBL bla coding plasmids in India and USA, respectively. Considering the fact that plasmid-born qnrB attach to the upstream of LexA [20], it can cause an increase of qnrB expression in ESBL+ E. coli when expose to quinolones. Therefore, in this study 30.9% of the isolates were qnrB+ and Peimani reported a 35.5% prevalence of this gene [7].…”