OBJECTIVES The aim of this study was to determine the spread of plasmid-mediated quinolone resistance determinants [qnr-like, aac(6')-Ib-cr and qepA genes] among nalidixic acid-resistant enterobacterial strains isolated from outpatients from Southeast Brazil, their transferability and the genetic structures associated with the qnr genes. METHODS The qnrA, qnrB and qnrS genes were screened by ...

background and aims: extended-spectrum β-lactamase (esbl) producing gram negative bacteria are resistant to penicillins, narrow and extended-spectrum cephalosporins, and aztreonam; also they are frequently resistant to trimethoprim-sulfamethoxazole, aminoglycosides, and quinolones. this study aimed to investigate the prevalence of plasmid-mediated quinolone resistance (pmqr) determinants qnra, ...

OBJECTIVE Quinolone resistance is usually caused by various chromosomal mutations, but has been more recently associated with plasmids which carry the qnr determinant. The aim of this study is to investigate the prevalence of qnr genes in clinical isolates of Enterobacteriaceae in Jamaica. METHODS A total of 255 non-duplicate fluoroquinolone-resistant Enterobacteriaceae clinical isolates, com...

A total of 225 isolates of Salmonella enterica serovar Typhimurium from food-producing animals collected between 2003 and 2007 were examined for the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants, namely qnrA, qnrB, qnrC, qnrD, qnrS, qepA and aac(6')Ib-cr, in Japan. Two isolates (0.8%) of S. Typhimurium DT104 from different dairy cows on a single farm in 2006 and 2007 w...

The aim of this study was to search for three plasmid-encoded, quinolone-resistant determinants: qnrA, qnrB, and qnrS. Thus, 460 Gram-negative strains belonging to 11 different genera (clinical, 347; non-clinical, i.e., from a rectal swab, 113), of which 40% were ciprofloxacin-resistant, were recovered from patients in an intensive care unit at the Istanbul Medical Faculty, Turkey, in the years...

OBJECTIVES To characterize the prevalence of plasmid-mediated quinolone resistance determinants qnr and aac(6')-Ib-cr in extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae. METHODS qnrA, qnrB, qnrS, aac(6')-Ib-cr and ESBL-encoding genes were detected by PCR. MICs of 10 antimicrobial agents were determined by Etest. PFGE was used to investigate the clo...

BACKGROUND Escherichia coli is an important bacterial species based on incidence and associated infection severity. Some E. coli strains produce extended-spectrum beta lactamase (ESBL) and are called ESBL-producing E. coli. These strains are resistant to most classes of cephalosporin and a number of other classes of antibiotics. Plasmids carrying qnr genes have been found to transmit quinolone ...

conclusions the most common qnr gene was qnrb, and none of the isolates carried qnra or qepa. the aac (6’)-ib-cr variant was the most prevalent pmqr gene, and it was associated with the prevalence of ciprofloxacin resistance in our esbl-producing isolates. results of the 123 isolates, 103 (83.73%) had one of the five pmqr genes, including 83 (83.83%) of the 99 e. coli strains and 20 (86.95%) of...

conclusions the high prevalence of quinolone resistance genes, which indicates antibiotic resistance, in the imam reza hospital of mashhad is a major concern. hence, the antibiotics prescription policy should be revised, and infection control measures should be improved. results eighty-six (43%) isolates were ciprofloxacin-resistant. the pct identified 85 (42.5%) of 200 e. coli isolates as esbl...