Direct detection of antibiotic resistance genes in specimens of chicken and pork meat.
Antibiotic resistance (AR) in bacteria, a major threat to human health, has emerged in the last few decades as a consequence of the selective pressure exerted by the widespread use of antibiotics in medicine, agriculture and veterinary practice and as growth promoters in animal husbandry. The frequency of 11 genes [tet(M), tet(O), tet(K), erm(A), erm(B), erm(C), vanA, vanB, aac (6')-Ie aph (2'')-Ia, mecA, blaZ] encoding resistance to some antibiotics widely used in clinical practice was analysed in raw pork and chicken meat and in fermented sausages as well as in faecal samples from the relevant farm animals using a molecular approach based on PCR amplification of bacterial DNA directly extracted from specimens. Some of the 11 AR genes were highly prevalent, the largest number being detected in chicken meat and pig faeces. The genes found most frequently in meat were tet(K) and erm(B); vanB and mecA were the least represented. All 11 determinants were detected in faecal samples except mecA, which was found only in chicken faeces. erm(B) and erm(C) were detected in all faecal samples. The frequency of AR genes was not appreciably different in meat compared to faecal specimens of the relevant animal except for vanB, which was more prevalent in faeces. Our findings suggest that AR genes are highly prevalent in food-associated bacteria and that AR contamination is likely related to breeding rather than processing techniques. Finally, the cultivation-independent molecular method used in this work to determine the prevalence of AR genes in foods proved to be a rapid and reliable alternative to traditional tools.
Garofalo
Cristiana
C
Department of Food Sciences, Università Politecnica delle Marche, via Ranieri, Montedago, 60131 Ancona, Italy.
Vignaroli
Carla
C
Zandri
Giada
G
Aquilanti
Lucia
L
Bordoni
Donatella
D
Osimani
Andrea
A
Clementi
Francesca
F
Biavasco
Francesca
F
D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D002645:Chickens; D004269:DNA, Bacterial / Q000737:chemistry; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016983:Enterococcus / Q000187:drug effects / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D005506:Food Contamination / Q000032:analysis* / Q000517:prevention & control; D005516:Food Microbiology; D005784:Gene Amplification; D006801:Humans; D008460:Meat / Q000382:microbiology*; D008461:Meat Products / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013210:Staphylococcus / Q000187:drug effects / Q000302:isolation & purification*; D013552:Swine
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial