Clemente L.,Iniav Institute Nacional Of Invest Agraria E Veterinaria |
Manageiro V.,National Institute of Health Dr Ricardo Jorge |
Manageiro V.,University of Porto |
Ferreira E.,National Institute of Health Dr Ricardo Jorge |
And 8 more authors.
International Journal of Food Microbiology | Year: 2013
A total of 1120 Salmonella spp. isolates, recovered from poultry, swine and food products of animal origin (bovine, swine and poultry) over the period of 2009-2011, were investigated in order to determine their serotype, susceptibility to a panel of eleven antimicrobials (A, ampicillin; Ct, cefotaxime; Cp, ciprofloxacin; Tm, trimethoprim; Su, sulfamethoxazole; C, chloramphenicol; S, streptomycin; G, gentamicin; T, tetracycline; NA, nalidixic acid; Fl, florfenicol), and the presence of resistance determinants of extended-spectrum cephalosporins. Overall, Salmonella Enteritidis was the most common serotype in all three animal species. In 618 isolates of poultry, 32.8% comprised S. Enteritidis, 18.3% Salmonella Havana and 16.5% Salmonella Mbandaka; in 101 isolates of pigs, 21.8% comprised Salmonella Rissen and Salmonella Typhimurium, 10.9% Salmonella Derby and Salmonella London. Salmonella I 4,,12:i:- was the most common serotype recovered from pork and beef food products comprising 32.6% and 30% of isolates respectively, followed by S. Rissen (26% and 24%) and S. Typhimurium (18.2% and 19%), respectively. In poultry products, S. Enteritidis was the most frequent serotype (62.7%), followed by S. Mbandaka (10.2%) and S. Derby (8.5%). Susceptibility profiles differed according to the origin of the isolates. Five multidrug resistant isolates (0.45%) were further characterized as extended-spectrum β-lactamase (ESBL) producers. Polymerase chain reaction and sequencing of the amplicons confirmed the presence of blaCTX-M-1 (n=2), blaCTX-M-14 (n=1), blaCTX-M-15 (n=1) and blaCTX-M-32 (n=1); blaSHV-12 and blaTEM-1 genes were also detected in two isolates of S. I 4,,12:i: Four isolates, two S. Havana and two S. I 4,,12:i:-, carried class 1 integrons and in three, two S. I 4,,12:i:- and one S. Havana, ISEcp1 was identified associated to blaCTX-M-1, blaCTX-M-32 and blaCTX-M-14 genes. Additionally, in one S. I 4,,12:i:- isolate, orf477 was identified linked to blaCTX-M-32. No plasmid mediated quinolone resistance-encoding genes were detected. Here, we report for the first time the presence of blaCTX-M genes in Salmonella enterica subsp enterica isolates recovered from poultry and food products of swine origin, in Portugal. © 2013 Elsevier B.V.