Occurrence and Antimicrobial Profile of Bacterial Pathogens in Former Foodstuff Meat Products Used for Pet Diets

Abstract

European legislation stipulates that food no longer intended for human consumption, due to commercial reasons, manufacturing problems, or some defect, can be used in pet feed. However, the presence of former foodstuffs in pet diets could constitute a public health issue because pets can act as reservoirs of antimicrobial resistance genes. In this study, for the first time, biological hazards due to the presence of Escherichia coli and Salmonella in former foodstuff meat products were evaluated. Among the 112 samples of packaged fresh meat (poultry, pork, and beef) collected from cold storage warehouses of a mass market retailer, the overall prevalence of E. coli and Salmonella, the prevalence of strains with multidrug resistance, the phenotypic and genotypic characteristics of strains that produce extended-spectrum β-lactamase, and the presence of biofilm producers were assessed. A high prevalence of E. coli was observed in former foodstuffs of poultry (100%), pork (100%), and beef (93.3%). Salmonella Derby and Salmonella Typhimurium were found in 11.5% of the poultry samples, and Salmonella Typhimurium was found in 13.3% of the pork samples. Salmonella was not recovered from the beef samples. Multidrug resistance was found in E. coli and Salmonella isolates from poultry, pork, and beef. Overall, 18.2% of E. coli isolates and 20% of Salmonella isolates were resistant to various types of antibiotics with various mechanisms of action. Salmonella isolates from pork are an important source of extended-spectrum β-lactamase production. Both E. coli and Salmonella were carriers of antibiotic resistance marker genes (blaTEM, blaSHV, and blaCTX-M) associated with β-lactamase production in poultry and pork. Approximately 30% of the E. coli isolates from the various types of meat were phenotypically biofilm producers, and all carried the fimH gene. These findings indicate that the use of former foodstuff meat products in pet diets can represent a risk for public health.

Raw diets for dogs and cats: a review, with particular reference to microbiological hazards

“…In contrast, just one of 480 (0.2%) conventionally processed dog food samples yielded Salmonella in a study from the USA (Nemser et al ). A recent study in the Netherlands reported Salmonella isolation from 20% of 35 commercial raw food samples (van Bree et al ), while in Italy, pork and chicken material available for pet food manufacture yielded Salmonella from 12% of samples (Bacci et al ). Surveillance of Salmonella contamination in pet food by the APHA in the UK (under animal by‐products regulations) reported isolations from raw versus processed food in ratios of approximately 6:1 in 2015 and 20:1 in 2016, despite most samples coming from the larger processed food sector (APHA ).…”

“…A higher prevalence of Salmonella in raw versus processed dog and cat foods was also reported in Egypt (Azza et al ). Serovars isolated in studies and surveillance of ingredients and raw food for pets or working dogs are diverse (Strohmeyer et al ) and include those considered to be of particular significance for human salmonellosis (Chengappa et al , Finley et al , Mehlenbacher et al , Bacci et al ). Indeed, in recent years in the UK, more than 50% of such regulated serovar isolations in animal feeding stuffs came from raw pet food, including tripe (APHA , ).…”

“…Multi‐resistant E. coli and Salmonella strains were prevalent among poultry and pork material available for pet food manufacture in Italy (Bacci et al ), and there is a particular concern in the UK about the use of imported poultry meat for RMBDs. The consumption by dogs and cats of multi‐resistant epidemic Salmonella serovars (such as S .…”

“…Multi-resistant E. coli and Salmonella strains were prevalent among poultry and pork material available for pet food manufacture in Italy (Bacci et al 2019), and there is a particular concern in the UK about the use of imported poultry meat for RMBDs. The consumption by dogs and cats of multi-resistant epidemic Salmonella serovars (such as S. Kentucky, S. Infantis, S. Stanley, S. Heidelberg and ciprofloxacin-resistant S. Enteritidis) that are not currently present in UK food animals (EFSA 2012, Springer et al 2014, Shah et al 2017) pose a risk of the subsequent incursion of such resistant strains into British poultry flocks via pets shedding the organisms.…”

“…(under "Coliforms");Bacci et al (2019),van Bree et al (2018),Azza et al (2014),Nemser et al (2014),Lenz et al (2009),Lefebvre et al (2008),Strohmeyer et al (2006) andFreeman & Michel (2001) (under "E. coli") CampylobacterBojanic et al…”