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 ...

The aim of this study was to explore the plasmid characteristics of eight clinical Enterobacteriaceae strains containing extended broad spectrum beta-lactamases and plasmid-mediated quinolone resistance. Plasmids were transferred by conjugation or transformation and resistance determinants were investigated by PCR. We showed that at least one plasmid harbouring qnrB or qnrS determinant was tran...

Methods: E. coli was isolated from 388 broiler chicken caecal samples from 22 abattoirs and from boot swabs from 442 turkey flocks over successive 1 year periods. CHROMagar ECC with and without cephalosporin antibiotics was used as isolation medium and the chicken study also used CHROMagar CTX. ESBL phenotype isolates were tested for the presence of blaCTX-M, blaOXA, blaSHV, blaTEM and ampC gen...

A new QepA4 variant was detected in an O86:H28 ST156-fimH38 Escherichia coli, showing a multidrug-resistance phenotype. PAβN inhibition of qepA4-harboring transconjugant resulted in increase of nalidixic acid accumulation. The qepA4 and catA1 genes were clustered in a 26.0-kp contig matching an IncF-type plasmid, and containing a Tn21-type transposon with multiple mobile genetic elements. This ...

OBJECTIVES The purpose of this study was to investigate the prevalence of extended spectrum β-lactamase (ESBL) genes in Escherichia coli isolated from post-weaning diarrhea (PWD) piglets in Heilongjiang province, China. METHODS Of 458 E. coli isolated from 589 fecal samples from PWD piglets, a total of 198 isolates were confirmed as ESBL producers by the double-disk synergy test (DDST). Polym...

Quinolone antibiotics have been commonly used to treat cases of multiple antibiotic resistance. Unfortunately, quinolone so much resisted by infectious bacterial agents. This study aimed evaluate the susceptibility some clinical isolates E. coli and determination plasmid-encoded resistance genes.
 Our results showed plasmid quinolone-resistance genes in following prevalence: qnr genes: S (...

OBJECTIVES To investigate the prevalence and characterization of 16S rRNA methylase-producing bacteria in a pig farm and its environment in East China. METHODS Enterobacteriaceae isolates and metagenomic DNA from 102 pig faecal samples from a pig farm and 97 soil samples taken in or around the farm were screened for the presence of 16S rRNA methylase genes. The clonal relationships of 16S rRN...

This work describes the characterization of plasmid-mediated quinolone-resistance (PMQR) genes from a multicenter study of ESBL-producing Enterobacteriaceae pediatric clinical isolates in Mexico. The PMQR gene-positive isolates were characterized with respect to ESBLs, and mutations in the GyrA and ParC proteins were determined. The phylogenetic relationship was established by PFGE and the tran...