Format

Send to

Choose Destination
Vet Microbiol. 2014 Jul 16;171(3-4):298-306. doi: 10.1016/j.vetmic.2014.01.030. Epub 2014 Feb 7.

Antimicrobial susceptibility of Salmonella isolates from healthy pigs and chickens (2008-2011).

Author information

1
Bayer Animal Health GmbH, Leverkusen, Germany. Electronic address: anno.jong@bayer.com.
2
Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium.
3
Bayer Animal Health GmbH, Leverkusen, Germany.
4
Animal Health Care Flanders, Torhout, Belgium.

Abstract

Using the agar dilution method, antimicrobial susceptibility to human-use antibiotics was determined among Belgian faecal Salmonella isolates from healthy pigs and broiler chickens. Both epidemiological cut-off values and clinical breakpoints were applied for interpretation of the results. Cephalosporin-resistant isolates were examined for the presence of genes encoding CTX-M, SHV, TEM and CMY β-lactamases. All isolates with decreased quinolone susceptibility were screened for plasmid-borne genes qnr, qepA and aac(6')-Ib-cr. In all, 368 Salmonella isolates were recovered from pigs and 452 from chickens. Clinical resistance to ciprofloxacin was absent in isolates of both host species, and was 1.9 and 13.1% to cefotaxime in pig and poultry isolates, respectively. Decreased susceptibility to cefotaxime amounted to 2.2 and 0.7%, whereas for ciprofloxacin this was 3.0 and 23.0% in pig and poultry isolates, respectively. Ciprofloxacin decreased susceptibility was limited to few serovars, mainly Paratyphi B. Multidrug resistance was markedly higher for pig isolates (39.7%) than for chicken isolates (17.3%). Sixty-six cefotaxime-resistant isolates, 59 from chickens and 7 from pigs, were phenotypically determined as ESBL/AmpC producers; predominantly Paratyphi B and Typhimurium serovars. BlaCTX-M (mostly blaCTXM-1, but also blaCTXM-2 and blaCTXM-9) and blaTEM-52 were the predominant ESBL genes. Only few isolates expressed SHV-12 or an AmpC enzyme (CMY-2). Isolates of four serovars carried qnr genes: Brandenburg and Llandof from pigs, both qnrS; Indiana and Paratyphi B from chickens with qnrB and qnrA. The latter isolate carried blaCTX-M-9 and was the only strain with a plasmid-borne quinolone resistance gene among the ESBL/AmpC producers. This Salmonella survey confirms that the ESBL/AmpC producers are particularly prevalent in chickens (12.8%), and much less in pigs (1.9%). A link between plasmid-borne quinolone resistance genes and ESBLs/AmpC was uncommon.

KEYWORDS:

Antimicrobial resistance; Chickens; Mechanisms of resistance; Pigs; Surveillance

PMID:
24598135
DOI:
10.1016/j.vetmic.2014.01.030
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center