Affiliation:
1. College of Veterinary Medicine, National Reference Laboratory of Veterinary Drug Residues, South China Agricultural University, Guangzhou 510642, China
2. Institute of Antibiotics, Huashan Hospital
3. School of Life Science, Foshan University, Foshan 528000, China
4. Institute of Biomedical Sciences, Fudan University, Shanghai 200040, China
Abstract
ABSTRACT
Three kinds of plasmid-mediated quinolone resistance (PMQR) determinants have been discovered and have been shown to be widely distributed among clinical isolates:
qnr
genes,
aac(6
′
)-Ib-cr
, and
qepA
. Few data on the prevalence of these determinants in strains from animals are available. The presence of PMQR genes in isolates from animals was determined by PCR amplification and DNA sequencing. The production of extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases in the strains was detected, and their genotypes were determined. The genetic environment of PMQR determinants in selected plasmids was analyzed. All samples of ceftiofur-resistant (MICs ≥ 8 μg/ml) isolates of the family
Enterobacteriaceae
were selected from 36 companion animals and 65 food-producing animals in Guangdong Province, China, between November 2003 and April 2007, including 89
Escherichia coli
isolates, 9
Klebsiella pneumoniae
isolates, and isolates of three other genera. A total of 68.3% (69/101) of the isolates produced ESBLs and/or AmpC β-lactamases, mainly those of the CTX-M and CMY types. Of the 101 strains, PMQR determinants were present in 35 (34.7%) isolates, with
qnr, aac(6
′
)-Ib
-
cr
, and
qepA
detected alone or in combination in 8 (7.9%), 19 (18.8%), and 16 (15.8%) strains, respectively. The
qnr
genes detected included one
qnrB4
gene, four
qnrB6
genes, and three
qnrS1
genes. Five strains were positive for both
aac(6
′
)-Ib
-
cr
and
qepA
, while one strain was positive for
qnrS1, aac(6
′
)-Ib
-
cr
, and
qepA. qnrB6
was flanked by two copies of IS
CR1
with an intervening
dfr
gene downstream and
sul1
and
qacE
Δ
1
genes upstream. In another plasmid,
aac(6
′
)-Ib-cr
followed
intI1
and
arr-3
was downstream. PMQR determinants are highly prevalent in ceftiofur-resistant
Enterobacteriaceae
strains isolated from animals in China. This is the first report of the occurrence of PMQR determinants among isolates from companion animals.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology
Reference42 articles.
1. Zoo Animals as Reservoirs of Gram-Negative Bacteria Harboring Integrons and Antimicrobial Resistance Genes
2. Avsaroglu, M. D., R. Helmuth, E. Junker, S. Hertwig, A. Schroeter, M. Akcelik, F. Bozoglu, and B. Guerra. 2007. Plasmid-mediated quinolone resistance conferred by qnrS1 in Salmonella enterica serovar Virchow isolated from Turkish food of avian origin. J. Antimicrob. Chemother.60:1146-1150.
3. Detection of CMY-2, CTX-M-14, and SHV-12 β-Lactamases in
Escherichia coli
Fecal-Sample Isolates from Healthy Chickens
4. Performance standards for antimicrobial disk and dilution susceptibility tests for bacteria isolated from animals. 2002
5. Performance standards for antimicrobial susceptibility testing: 15th informational supplement. 2005
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