title: 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 blaCMY-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.
authors.affiliation: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa, Fe, Argentina.
authors.forename: Martín
authors.initials: M
authors.lastname: Marchisio
authors.affiliation: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa, Fe, Argentina.
authors.forename: Ayelén
authors.initials: A
authors.lastname: Porto
authors.affiliation: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa, Fe, Argentina.
authors.forename: Romina
authors.initials: R
authors.lastname: Joris
authors.affiliation: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa, Fe, Argentina.
authors.forename: Marina
authors.initials: M
authors.lastname: Rico
authors.affiliation: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa, Fe, Argentina.
authors.forename: María R
authors.initials: MR
authors.lastname: Baroni
authors.affiliation: Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa, Fe, Argentina.
authors.forename: José
authors.initials: J
authors.lastname: Di Conza
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001118:Argentina; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D010045:Outpatients; D010802:Phylogeny; D010957:Plasmids / Q000032:analysis; D015363:Quinolones / Q000494:pharmacology*; D014552:Urinary Tract Infections / Q000382:microbiology*; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015363:Quinolones; D047090:beta-Lactams