Clinically relevant multidrug resistant Salmonella enterica in swine and meat handlers at the abattoir.
The presence of multidrug resistant (MDR) Salmonella serotypes in slaughtered swine, carcasses, meat and meat handlers is scarcely evaluated. Recently we demonstrated that diverse Salmonella serotypes are frequently present in swine, pork meat and carcasses, and meat handlers at Portuguese abattoirs. Here we have characterized their antibiotic resistance phenotypes and genotypes, helping elucidate the flow of MDR Salmonella in the food chain. Testing 60 Salmonella isolates from different serotypes, the highest frequencies of resistance were observed for tetracycline (T) [70% (n=42/60), tet(A)/tet(B)/tet(G)], streptomycin (S) [63% (n=38/60), aadA2/strA/strB], sulfamethoxazole (Sul) [62% (n=37/60), sul1/sul2/sul3] and ampicillin (A) [57% (n=34/60), blaPSE-1/blaTEM]. Thirty-seven percent (n=22/60) carried class 1 integrons and multidrug resistance was frequently observed (63% n=38/60), including those serotypes common to human infections [S. Typhimurium 78% n=25/32; S. 4,[5],12:i:- 67% n=2/3; S. Rissen 75% (n=3/4); S. London 67% n=2/3; S. Derby 55%; n=6/11)]. The emergent S. 4,[5],12:i:- isolates were mostly characterized by ASSuT phenotype [blaTEM/strA-strB/sul2/tet(B)], typical of the European clone, while for the first time the ST phenotype [strA-strB-tet(A)-tet(B)] was also observed. Moreover, we report a first finding of a MDR phenotype in S. London [ANSSuT; blaTEM-strA-strB-sul2-tet(A)]. Our findings suggest that the abattoir environment and the slaughter operations seem not only to harbor MDR serotypes that originated in the pig reservoir, but also propagate them through cross-contamination processes, involving meat handlers. The present study suggests a probable relationship between swine and human salmonellosis throughout the food chain, which is of interest for epidemiological, animal health and public health purposes.
ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; CECA-ICETA, Centro de Estudos de Ciência Animal, Universidade do Porto, Rua D. Manuel II Apartado 55412, 4051-401 Porto, Portugal. Electronic address: egomesneves@mail.icav.up.pt.
Eduarda
E
Gomes-Neves
Faculdade de Ciências da Nutrição e Alimentação, Universidade do Porto, Rua Dr. Roberto Frias, 4200 Porto, Portugal; REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira n° 228, 4050-313 Porto, Portugal. Electronic address: patriciaantunes@fcna.up.pt.
Patrícia
P
Antunes
CECA-ICETA, Centro de Estudos de Ciência Animal, Universidade do Porto, Rua D. Manuel II Apartado 55412, 4051-401 Porto, Portugal; INSA, Instituto Nacional de Saúde Dr. Ricardo Jorge, Laboratório Nacional de Referência da Resistência Antimicrobiana, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Electronic address: vera.manageiro@insa.min-saude.pt.
Vera
V
Manageiro
ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; IPATIMUP, Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal. Electronic address: fgartner@ipatimup.pt.
Fátima
F
Gärtner
CECA-ICETA, Centro de Estudos de Ciência Animal, Universidade do Porto, Rua D. Manuel II Apartado 55412, 4051-401 Porto, Portugal; INSA, Instituto Nacional de Saúde Dr. Ricardo Jorge, Laboratório Nacional de Referência da Resistência Antimicrobiana, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Electronic address: manuela.canica@insa.min-saude.pt.
Manuela
M
Caniça
CECA-ICETA, Centro de Estudos de Ciência Animal, Universidade do Porto, Rua D. Manuel II Apartado 55412, 4051-401 Porto, Portugal; INSA, Instituto Nacional de Saúde Dr. Ricardo Jorge, Laboratório Nacional de Referência da Resistência Antimicrobiana, Av. Padre Cruz, 1649-016 Lisboa, Portugal. Electronic address: jose.costa@insa.min-saude.pt.
José Manuel Correia
JM
da Costa
REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira n° 228, 4050-313 Porto, Portugal. Electronic address: lpeixe@ff.up.pt.
Luísa
L
Peixe
D000003:Abattoirs / Q000706:statistics & numerical data*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005516:Food Microbiology; D005838:Genotype; D006801:Humans; D032023:Integrons / Q000235:genetics; D008826:Microbial Sensitivity Tests; D011174:Portugal; D012480:Salmonella Infections / Q000382:microbiology*; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D012703:Serotyping; D013552:Swine
D000900:Anti-Bacterial Agents
Antibiotic resistance; Meat; S. Typhimurium monophasic variant; Salmonella; Swine