Superbugs in the supermarket? Assessing the rate of contamination with third-generation cephalosporin-resistant gram-negative bacteria in fresh Australian pork and chicken

Abstract

BackgroundAntibiotic misuse in food-producing animals is potentially associated with human acquisition of multidrug-resistant (MDR; resistance to ≥ 3 drug classes) bacteria via the food chain. We aimed to determine if MDR Gram-negative (GNB) organisms are present in fresh Australian chicken and pork products.MethodsWe sampled raw, chicken drumsticks (CD) and pork ribs (PR) from 30 local supermarkets/butchers across Melbourne on two occasions. Specimens were sub-cultured onto selective media for third-generation cephalosporin-resistant (3GCR) GNBs, with species identification and antibiotic susceptibility determined for all unique colonies. Isolates were assessed by PCR for SHV, TEM, CTX-M, AmpC and carbapenemase genes (encoding IMP, VIM, KPC, OXA-48, NDM).ResultsFrom 120 specimens (60 CD, 60 PR), 112 (93%) grew a 3GCR-GNB (n = 164 isolates; 86 CD, 78 PR); common species were Acinetobacter baumannii (37%), Pseudomonas aeruginosa (13%) and Serratia fonticola (12%), but only one E. coli isolate. Fifty-nine (36%) had evidence of 3GCR alone, 93/163 (57%) displayed 3GCR plus resistance to one additional antibiotic class, and 9/163 (6%) were 3GCR plus resistance to two additional classes. Of 158 DNA specimens, all were negative for ESBL/carbapenemase genes, except 23 (15%) which were positive for AmpC, with 22/23 considered to be inherently chromosomal, but the sole E. coli isolate contained a plasmid-mediated CMY-2 AmpC.ConclusionsWe found low rates of MDR-GNBs in Australian chicken and pork meat, but potential 3GCR-GNBs are common (93% specimens). Testing programs that only assess for E. coli are likely to severely underestimate the diversity of 3GCR organisms in fresh meat.Electronic supplementary materialThe online version of this article (10.1186/s13756-018-0322-4) contains supplementary material, which is available to authorized users.

Metallo-β-lactamase and AmpC genes in Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa isolates from abattoir and poultry origin in Nigeria

“…This is a possible indication of the stealth and exceptional emergence and spread of resistant GNB in the non-hospital environment. The results of this study were in parallel with the previous studies from Australia, China, and Switzerland that were suggestive of the ability of resistant GNB to cause a public health problem through the food chain, especially in climes where antibiotics are used irrationally in non-clinical practices [ 17 – 20 ]. In this study, the high resistance rates (> 70%) against third-generation cephalosporins (TGCs) were similar to previous report by Otokunefor et al [ 21 ] from Nigeria who reported a resistance rate of ≥80% against TGCs family.…”

“…Abattoirs and poultry farms are good grounds for the evolution and spread of antibiotic resistant bacteria [ 17 , 18 ]. The result of the AST in this study revealed a high level of resistance of E. coli , K. pneumoniae , and P. aeruginosa to more than 50% of the tested antibiotic panels including the cephalosporins, aminoglycosides, quinolones, and carbapenems.…”

Raw Meat Contaminated with Cephalosporin-Resistant Enterobacterales as a Potential Source of Human Home Exposure to Multidrug-Resistant Bacteria

“…Currently, they are increasingly often found in farm animals [23], in raw meat [24], eggs [25], and food [26,27], which confirms the exchange of organisms or genes between different reservoirs [28,29]. Thus, the data suggest that farm animals and meat of animal origin are among the reservoirs of ESBL and CR bacteria [30][31][32][33][34][35][36][37][38][39][40].…”

Antimicrobial Resistant Pathogens Detected in Raw Pork and Poultry Meat in Retailing Outlets in Kenya

“…Furthermore, a prevalence of 58.1% in Salmonella spp. [ 33 ], 18% in E. coli [ 34 ], 11.5% in P. aeruginosa [ 35 ], and 5.6% in S. aureus spp. [ 36 ] has been reported in pork sample from retail markets.…”