Transmission of Bacterial Zoonotic Pathogens between Pets and Humans: The Role of Pet Food

Application of hydraulic modelling and quantitative microbial risk assessment (QMRA) for cloudburst management in cities with combined sewer systems

Urban cloudburst management may include the intentional temporary storage of flood water in green recreational areas. In cities with combined sewers, this will expose the population visiting the area to sewage and increase the risk of diarrhoeal disease. We present a unique approach to estimate the risk of diarrhoeal disease after urban flooding. The exposure scenario was: rainwater mixed with sewage flows into a park; sewage with pathogens deposit on the grass; after discharge, a baby plays on the grass and is exposed to the pathogens in the deposited sewage by hand-to-mouth transfer. The work included modelling the transport of sewage into four parks intended to be flooded during future cloudbursts. A flood simulation experiment was conducted to estimate the deposition of pathogens from sewage to grass and transfer from grass to hand. Hand-to-mouth transfer, based on literature values, was used to estimate the ingested dose of pathogens. The probability of illness was estimated by QMRA. The estimated average probability of illness varied between 0.03 and 17%. If the probability of illness is considered unacceptable, the cloudburst plans should be changed, or interventions, e.g. informing the public about the risk or restricting access to the flooded area, should be implemented.

Consumer attitudes toward bacteriophage applications to pet food

This study used a two-part questionnaire to investigate consumer knowledge and attitudes toward bacteriophage applications in pet food, pet food safety, and environmental sustainability. Part 1 included questions about pet food safety, sustainability, and knowledge and attitudes toward bacteriophages. Next, participants reviewed educational materials about each, and Part 2 assessed if this increased knowledge of, or changed attitudes toward, bacteriophage application. Participants (n = 80), were recruited through Amazon Mechanical Turk (MT) (n = 45) and Social Media (SM) (n = 35). Mean responses in Part 1 and Part 2 were compared by paired t-tests, and mean responses between MT and SM were compared by t-tests. Participants reported pet food safety was important to them (combined proportion strongly agree or agree, mean ± SD) (75/80, 94%, MT 4.66 ± 0.60, SM 4.71 ± 0.95) and were most concerned with raw pet food safety (51/80, 64%, MT 3.88 ± 0.80, SM 3.17 ± 1.40). Participants rated environmental sustainability as important (61/80, 76%, MT 3.86 ± 0.94, SM 3.97 ± 0.66); however, it was not a strong driver of pet food purchasing (26/80, 33%, MT 3.31 ± 1.25, SM 2.82 ± 0.82). Overall, data showed an increase in knowledge of bacteriophages following a review of educational material. However, in the SM group, no statistically significant difference was observed in the comfort eating food with bacteriophage additives (SM Part 1 3.37 ± 1.05, SM Part 2 3.48 ± 1.12, p = 0.279), whereas the MT group did show an increase (MT Part 1 3.57 ± 1.01, MT Part 2 4.08 ± 0.92, p < 0.001). In the SM group, no statistically significant difference was observed in comfort feeding their pet food with bacteriophage additives (SM Part 1 3.40 ± 1.03, SM Part 2 3.45 ± 1.14, p = 0.571), whereas the MT group did show an increase (MT Part 1 3.57 ± 0.98, MT Part 2 4.31 ± 0.84, p < 0.001). The strongest objections related to safety concerns (20/53, 38%, MT 2.83 ± 0.96, SM 3.27 ± 0.84). These results demonstrate that despite increasing knowledge, there is still hesitancy among some consumers toward bacteriophage applications in pet food.

Anti-microbial resistance of Salmonella isolates from raw meat-based dog food in Japan

Background

Salmonella contamination of raw meat‐based diets (RMBDs) for pets poses a major public health concern but has not been investigated in Japan.

Objective

To investigate Salmonella contamination in RMBDs for dogs marketed in Japan and the anti‐microbial resistance profiles of the Salmonella isolates.

Methods

Sixty commercial RMBD samples were collected in the Okayama and Osaka Prefectures, Japan, between December 2016 and March 2017. The obtained Salmonella isolates were serotyped, their anti‐microbial resistance patterns were determined, and the anti‐microbial‐resistant isolates were screened for the presence of resistance genes by polymerase chain reaction.

Results

Salmonella enterica subsp. enterica was detected in seven of the 60 RMBD samples. Among them, five isolates were identified as S. Infantis (n = 3), S. Typhimurium (n = 1) and S. Schwarzengrund (n = 1), while the serotypes of two isolates were unable to be identified. All isolates were susceptible to ampicillin, cefazolin, cefotaxime and gentamycin. Two isolates were resistant to more than one anti‐microbial agent; one of the S. Infantis isolates was resistant to streptomycin, kanamycin, tetracycline and trimethoprim, while the S. Typhimurium isolate was resistant to nalidixic acid, ciprofloxacin and chloramphenicol. The S. Schwarzengrund isolate was resistant to tetracycline. Additionally, the S. Typhimurium isolate harboured the anti‐microbial resistance gene gyrA with a mutation corresponding to Ser‐83→Phe amino acid substitution.

Conclusion

The study findings suggest that RMBDs for dogs marketed in Japan can be a potential source of Salmonella infection for dogs and humans including infections caused by quinolone‐resistant isolates.

The current study's objective was to determine the prevalence of Salmonella contamination in RMBD for dogs and the antimicrobial resistance profiles of these isolates. Therefore, the incidence of Salmonella contamination in RMBD for dogs currently sold in Japan was surveyed. Salmonella was detected in seven of the 60 raw food samples.

Raw Meat-Based Pet Feeding and Food Safety: Netnography Study of Pet Owner Comments and Review of Manufacturers' Information Provision

ABSTRACT

Feeding raw meat to domestic pets is a popular practice. Because of the potential food safety implications associated with handling raw meat, concerns about pet owner health have increased. For this study, a netnographic content analysis approach was used to analyze posts from Pet Forums Community online archives related to raw meat-based feeding and food safety (n = 308). United Kingdom manufacturer and supplier Web sites (n = 33) were reviewed for provision of food safety information related to raw meat-based pet feeding. The data were analyzed using a qualitative thematic approach and quantitative methods. Pet owner forum comments indicated potential malpractices and indifference toward possible food safety hazards when preparing raw meat-based pet food. Many were risk aware but indicated confusion regarding appropriate food safety practices. Although emotional concern about the safety of pets and children was expressed, contracting a foodborne disease was not perceived as a personal risk. In addition, the review identified that most (61%) manufacturer and supplier Web sites failed to provide food safety instructions or warnings to pet owners regarding raw meat-based pet food. Information was inconsistent and varied across sources. The most comprehensive sources of information were provided by manufacturers approved by the United Kingdom Pet Food Manufacturers' Association. This is the first netnography study to explore pet owner online reports and the provision of food safety information related to raw pet feeding. Findings suggest pet owners may not fully appreciate the potential risks associated with raw meat-based pet feeding. Consequently, there is a need for credible and consistent strategies to inform pet owners about potential implications associated with feeding raw meat to pets, as well as about safe food handling practices.

HIGHLIGHTS

Low Number of Owner-Reported Suspected Transmission of Foodborne Pathogens From Raw Meat-Based Diets Fed to Dogs and/or Cats

The aim of this worldwide survey was to determine owner-reported frequency of pathogen transmission to humans living in or in contact with households feeding their pets raw, minimally processed (MP) diets. A total of 5,611 responses were gathered from 62 countries with 77.1% of households feeding only MP diets to dog and/or cat(s) with no confirmed cases of pathogen transmission or infection by laboratory testing. Eleven households (0.20%; 95% CI, 0.10–0.36) were classified as having experienced “probable” transmission, and 20 households (0.36%; 95% CI, 0.22–0.56) were classified as having experienced “possible” transmission to result in a total of 31 households (0.55%; 95% CI, 0.38–0.79) being identified as potential cases of transmission. The remainder of households (n = 5,580 = 99.45%; 95% CI, 99.21–99.62) were not considered to have experienced potential transmission of foodborne pathogens based on their responses to the survey. The most frequently reported pathogens were Salmonella (n = 11, 0.2%), Campylobacter (n = 6, 0.1%), and Escherichia coli (n = 4, 0.1%), with the most common age group being adults age 18–65 (n = 29, 78.4% of cases). Beef and chicken were the most common proteins reported as being fed in case households, although this was not associated with pathogen transmission. Households feeding a greater number of different protein sources, including pork, turkey, duck, rabbit, and salmon, were associated with decreased risk of pathogen transmission. Additional risk factors associated with pathogen transmission included preparing either MP diets in a separate location, with different utensils than human food, mixing MP diets with dry (kibble) diets and feeding a limited variety of protein sources. Based on the results of this survey, confirmed pathogen transmission from MP diets to humans appears to be rare. We conclude that potential or probable cases of pathogen transmission is likely dependent upon hygiene and food safety measures, and more education surrounding food safety should reduce risk.

Genomic diversity and resistome profiles of Salmonella enterica subsp. enterica serovar Kentucky isolated from food and animal sources in Ireland

Salmonella enterica subsp. enterica serovar Kentucky is frequently isolated from poultry, dairy and beef cattle, the environment and people with clinical salmonellosis globally. However, the sources of this serovar and its diversity and antimicrobial resistance capacities remain poorly described in many regions. To further understand the genetic diversity and antimicrobial sensitivity patterns among S. Kentucky strains isolated from non-human sources in Ireland, we sequenced and analysed the genomes of 61 isolates collected from avian, bovine, canine, ovine, piscine, porcine, environmental and vegetation sources between 2000 and 2016. The majority of isolates (n = 57, 93%) were sequence type (ST) 314, while only three isolates were ST198 and one was ST152. Several isolates were multidrug-resistant (MDR) and 14 carried at least one acquired antimicrobial resistance gene. When compared to a database of publicly available ST314, four distinct clades were identified (clades I-IV), with the majority of isolates from Ireland clustering together in Clade I. Two of the three ST198 isolates were characteristic of those originating outside of the Americas (Clade ST198.2), while one was distantly clustered with isolates from South and North America (Clade ST198.1). The genomes of the two clade ST198.2 isolates encoded Salmonella Genomic Island 1 (SGI1), were multidrug-resistant and encoded polymorphisms in the DNA gyrase (gyrA) and DNA topoisomerase (parC) known to confer resistance to fluoroquinolones. The single ST152 isolate was from raw beef, clustered with isolates from food and bovine sources in North America and was pan-susceptible. Results of this study indicate that most S. Kentucky isolates from non-human sources in Ireland are closely related ST314 and only a few isolates are antimicrobial-resistant. This study also demonstrates the presence of multidrug-resistant ST198 in food sources in Ireland.

Exploring Food Safety Perceptions and Self-Reported Practices of Pet Owners Providing Raw Meat-Based Diets to Pets

ABSTRACT

The growing popularity of raw meat-based diets for pets is accompanied by increasing concern regarding possible health implications of this practice for pet owners through the storage and preparation of raw meat. This study aimed to explore pet owners' knowledge and perceptions about the safety of raw meat-based feeding and to determine self-reported food safety practices during raw meat-based pet food preparation. An online questionnaire was distributed via social media platforms and completed by pet owners practicing raw meat-based feeding (n = 174). Almost all participants (95%) reported confidence that their pets' raw meat-based food is safe. Two-thirds of respondents (67%) reported that they had researched food safety information regarding raw meat-based feeding, yet only 8% asked a veterinarian for food safety advice. Respondents were aware of pathogens that may be present in raw meat-based diets and of food safety practices; however, they did not report consistent implementation of appropriate food safety practices. Malpractices, such as rinsing of raw meat (27%) and absence of segregation of utensils and kitchen surfaces (52%), were reported. The risk to pet owners of foodborne illness associated with raw meat-based feeding was perceived to be low by 89% of pet owners. Participants perceived low susceptibility to foodborne illness but high self-efficacy, which may be an indication of optimistic bias. This study has identified a need to increase pet owners' awareness of the possible risks to human health associated with raw meat-based feeding of animals. The provision of comprehensive food safety information, intended to target the perceptions of pet owners identified in this study, is needed to improve pet owners' food safety practices and thus to reduce the potential food safety risks associated with raw meat preparation and storage in the domestic environment.

HIGHLIGHTS

Insights into Commercial Pet Foods

Veterinarians are faced with the challenge of understanding and discussing the wide array of commercial pet foods with their clients. To promote these discussions, a pet food processing categorization system is applied to define familiar heat processed dry and can pet foods as ultra-processed commercial diets (UPCD) and other less processed diets as minimally processed commercial diets. A review of the FDA pet food recalls on commercial diets are used to discuss well-known health risks, such as nutritional imbalances, bacterial pathogens, aflatoxin, and toxic contaminations. A less-known concern of advanced glycation end products found in UPCDs is presented.

Effects of "fresh mechanically deboned meat" inclusion on nutritional value, palatability, shelf-life microbiological risk and digestibility in dry dog food

Fresh mechanically deboned meat (MDM) is usually claimed as high-quality ingredient on dry pet food recipes and this aspect may positively influence consumer choice. It is important to determine the scientifically sustainability of this claim and to assess the microbiological safety of MDM inclusion in dry pet food. Objectives were: 1) to evaluate the effect of inclusion of MDM in dry dog food on fatty acid profile and in vivo and in vitro digestibility, proposing a new system (Daisy^II Incubator) to measure the in vitro digestibility for dogs; 2) to compare palatability of dry dog food containing MDM with dry dog food in which meat by-products (MBP) are the only animal protein sources; 3) to determine, whether or not, the inclusion of that ingredient changes the microbiology and the storage quality. Results indicated that MDM product was characterized by significant higher nutritional value in terms of fatty acids profile, in vitro digestibility (HV-IVD method) and lower palatability than the MBP product. Microbiological risk assessment showed no microbiological hazards for either product. After 6-months storage, the total mesophilic bacterial count ranged between 1.77 and 2.09 log CFU/g feed, while polyamine values were higher in the MDM (0.37 g/kg) than in the MBP (0.27 g/kg). The Daisy^II Incubator was found to be a valid instrument for studying in vitro digestibility also for dogs, providing data simply, quickly, with less variability and costs than in vivo trials. In conclusion, MDM inclusion in dry dog food is microbiologically safe and it can improve its nutritional quality, at the expense of a reduced palatability. The higher polyamine levels fount in MDM-enriched petfood after 6-months storage, however, may represent a possible hazard, and further studies are still warranted.

Microbiological Hazards in Dry Dog Chews and Feeds

Nowadays, dogs are usually equally treated with other family members. Due to the growing caregivers' awareness, the pet foods industry is changing dynamically. Pet foods are manufactured with a myriad of ingredients. Few authors of scientific papers deal with the topic of foods products' safety for pet animals, assessed from the perspective of their caregivers. Despite the many methods of producing foods of the highest quality, there are still cases of contamination of pet foods and treats. In the case of dried chews for dogs, bacteria of the genus Salmonella are the most common risk. In the case of both dry and wet foods, in addition to many species of bacteria, we often deal with mold fungi and their metabolites, mycotoxins. This article presents selected microbiological risks in dog foods and treats, and analyzes the Rapid Alert System for Food and Feed (RASFF) system (2017-2020) for pathogenic microorganisms in dried dog chews, treats and foods. In this period, pet food-related notifications were registered, which were categorized into different types. Analyzing the RASFF notifications over the period, it has been shown that there are still cases of bacterial contamination of dog foods and treats, while in terms of the overall mycotoxin content, these products may appear safe.

Risk of Foodborne Illness from Pet Food: Assessing Pet Owners' Knowledge, Behavior, and Risk Perception

Pet food has been identified as a source of pathogenic bacteria, including Salmonella and Escherichia coli. A recent outbreak linked to Salmonella -contaminated pet treats infected over 150 people in the United States. The mechanism by which contaminated pet food leads to human illness has not been explicated. Pet owners' food safety knowledge and their pet food handling practices have not been reported. This study evaluated pet owners' food safety knowledge and pet-food handling practices through an online consumer survey. The survey consists of 62 questions and assesses (1) owners' food safety knowledge and pet-food handling practices; (2) owners' interaction with pets; (3) owners' risk perception related to their own health, their children's health, and their pets' health. The survey was pilot-tested among 59 pet owners before distribution to a national consumer panel, managed by Qualtrics XM. All participants (n=1,040) were dog and/or cat owners in the United States. Almost all pet owners interacted with their pets (93%) and most cuddled, allowed their pets to lick them, and slept with their pets. Less than one-third of pet owners washed their hands with soap after interacting with their pets. Over half (58%) the owners reported washing their hands after feeding their pets. Most pet owners fed their pets dry pet food and dry pet treats. Some fed their pets raw meat or raw animal product (RAP) diets because they believed these diets to be beneficial to their pet's overall health. Many owners (78%) were unaware of pet food recalls or outbreaks associated with foodborne pathogens. Less than 25% considered dry pet foods and treats as a potential source of foodborne pathogens. The findings of this study indicated the need for consumer education about pet food handling. The data collected can assist in developing more accurate risk assessment models and consumer education related to pet food handling.

Catching a glimpse of the bacterial gut community of companion animals: a canine and feline perspective

Dogs and cats have gained a special position in human society by becoming our principal companion animals. In this context, efforts to ensure their health and welfare have increased exponentially, with in recent times a growing interest in assessing the impact of the gut microbiota on canine and feline health. Recent technological advances have generated new tools to not only examine the intestinal microbial composition of dogs and cats, but also to scrutinize the genetic repertoire and associated metabolic functions of this microbial community. The application of high-throughput sequencing techniques to canine and feline faecal samples revealed similarities in their bacterial composition, with Fusobacteria, Firmicutes and Bacteroidetes as the most prevalent and abundant phyla, followed by Proteobacteria and Actinobacteria. Although key bacterial members were consistently present in their gut microbiota, the taxonomic composition and the metabolic repertoire of the intestinal microbial population may be influenced by several factors, including diet, age and anthropogenic aspects, as well as intestinal dysbiosis. The current review aims to provide a comprehensive overview of the multitude of factors which play a role in the modulation of the canine and feline gut microbiota and that of their human owners with whom they share the same environment.

Current advances in molecular subtyping using multilocus variable number of tandem repeat analysis of Salmonella Enteritidis and Salmonella Typhimurium in Egyptian chickens

Aim:

This study aimed to characterize the genetic diversity, evolutionary level, and prevalence of genotypes of common isolates of Salmonella (Salmonella Enteritidis and Salmonella Typhimurium). Using one of the most advanced molecular recognition techniques, multilocus variable number of tandem repeat analysis (MLVA), we characterized the genotype and prevalence of S. Enteritidis and S. Typhimurium.

Materials and Methods:

One hundred and twenty-five internal organ samples were collected from the major chicken slaughterhouses in Egypt, and Salmonella species were isolated. PCR was utilized to amplify the IE-1 and Flic-C genes to identify S. Enteritidis and S. Typhimurium DNA, respectively, from Salmonella isolates. MLVA was applied on nine samples of S. Enteritidis DNA and three samples of S. Typhimurium DNA. Six variable number tandem repeat (VNTR) loci (Sal02, Sal04, Sal06, Sal10, Sal20, and Sal23) were amplified.

Results:

Of the examined samples (n=125), a total of 12 isolates (9.6%) were either identified as Enteritidis or Typhimurium. PCR-mediated amplification of IE-1 and Flic-C revealed that 75% (n=9) of the 12 Salmonella isolates were S. Enteritidis and 25% (n=3) were S. Typhimurium. The six loci amplified through MLVA had allelic diversity. The most discriminatory heterogenic locus for S. Enteritidis was Sal20. Sal04 and Sal23 were the most discriminatory heterogenic loci for S. Typhimurium. VNTR allelic profile analysis revealed nine unique genotypes for S. Enteritidis and three for S. Typhimurium.

Conclusion:

This study was the first to use MLVA analysis to identify S. Enteritidis and S. Typhimurium strains isolated from chickens in Egypt. The molecular typing data reported herein allowed us to characterize the genotypes of S. Enteritidis and S. Typhimurium that are most prevalent in Egyptian chickens. Moreover, this epidemiological information provides valuable insight on how to prevent disease transmission. Moreover, our methods provide an alternative to traditional serotyping techniques that may produce inaccurate strain identifications for organisms with rough lipopolysaccharide structures.

When Pet Snacks Look Like Children's Toys! The Potential Role of Pet Snacks in Transmission of Bacterial Zoonotic Pathogens in the Household

Recent foodborne pathogen outbreaks associated with dry pet food and treats have focused the attention on these products as vehicles of pathogens for both pets and their owners. This study investigates the purchasing habits of dog owners and determines if and in what form pet snacks can be potentially dangerous for humans, especially for children. For these purposes, questionnaires collected from 406 dog owners were evaluated and microbiological analyses were performed on 120 dry pet snacks. The shape of the pet snack affects the purchase (median score, Mdn = 6.4) and the star bone was the preferred one (Mdn = 7.1). Most of the participants (76.0%; p < 0.001) stated that snacks are attractive to their children and that the possibility for children to get in contact with pet snacks is rare, but not implausible (Mdn = 3.1). Indeed, more than 6% of respondents admitted that there had been incidents of involuntary ingestion of pet snacks, with fever and gastrointestinal manifestations. Microbiological analyses showed that 119 dry pet snacks analyzed of a total of 120 (99.2%) were in good sanitary condition except for one sample where the presence of Listeria ivanovii was confirmed. The upward trend in the presence of pets in households and the strong and continuous growth in value and volume of the pet food market led researchers to analyze possible public health issues. Children and infants in particular are the most exposed subjects as they are more likely to come into contact with pet snacks, attracted by a shape similar to that of a toy. For this reason, although our findings did not highlight important microbiological contamination of pet snacks, it would be useful to standardize food safety criteria with those for human food from a One Health perspective.

Pet Ownership and Pet Type Influence Food Safety in the Home: Evidence from a National Survey

ABSTRACT

Physical contact between humans and their pets increases the potential for zoonotic disease transmission. This study used the 2016 U.S. Food and Drug Administration (FDA) Food Safety Survey to compare the food handling behaviors of pet owners and non-pet owners, because poor food handling and hygiene habits can increase the likelihood of disease transmission from animals to humans. Results show that both pet ownership and pet type were important in predicting food safety behaviors. After controlling for sociodemographic factors included in this study (gender, age, household income, household size, and race or ethnicity), pet ownership was significantly associated with overall food safety practices and, more specifically, with better hand washing behaviors, kitchen cleaning, and ownership and use of a food thermometer, as well as a greater awareness of foodborne pathogens. Cat owners and cat-dog owners had better overall food safety practices and better hand washing behaviors compared with those of dog owners. After controlling for sociodemographic variables, there were no significant associations between pet ownership and perception of risks associated with unsafe food handling practices.

HIGHLIGHTS

Pet Food Quality Assurance and Safety and Quality Assurance Survey within the Costa Rican Pet Food Industry

Costa Rican animal feed production is continually growing, with approximately 1,238,243 metric tons produced in 2018. Production-wise, pet cat and dog food are in fifth place (about 41,635 metric tons per year) amongst animal feeds, and it supplies up to 90% of the national market. Pet food production has increased as a response to the increase in the population of dogs and cats in Costa Rica, where 50.5% of households own at least one dog and indicates more responsible ownership in terms of feeding pets. Part of the process of making dry pet food involves a thermal process called extrusion, which is capable of eliminating the microbial load. However, extrusion can compromise nutritional quality to some extent by denaturing proteins, oxidizing lipids, and reducing digestibility. The objective of this study was to evaluate the quality and safety of dry pet food and to assess the effect of the extrusion process on digestibility and the quality of proteins, amino acids, and fatty acids. Pet food samples were collected before and after extrusion and were used to evaluate Good Manufacturing Practices (GMP), based on Central American Technical Regulation (RTCA 65.05.63:11). In general terms, weaknesses in infrastructure, documentary evidence, and post-process practices were observed in two Costa Rican feed manufactories. Feed safety was surveyed through the analysis of Salmonella spp., Escherichia coli, Listeria spp., Staphylococcus aureus, aerobic mesophilic microorganisms, fungi, and yeasts counts. The extrusion process effectively reduced pathogenic microorganisms, and showed no effect on the digestibility of dog food (p = 0.347), however, it could reduce the availability of some nutrients (e.g., amino acids, fatty acids). Furthermore, a retrospective diagnosis was made for puppy food (n = 68), dog food (n = 158), and cat food (n = 25), to evaluate the history of nutritional quality and safety. Finally, it can be confirmed that the correct implementation of GMP allows feed manufacturers to deliver a product of optimum texture, smell, nutritional composition, and safety.

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

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 ( bla_TEM, bla_SHV, and bla_CTX-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.

Predicting Salmonella Typhimurium reductions in poultry ground carcasses

To improve understanding of Salmonella Typhimurium LT2 inactivation in ground poultry carcasses, a series of experiments were carried out at multiple temperatures. Subsequently, a non-linear model was developed to predict Salmonella inactivation at composting and low rendering temperatures. The Salmonella inactivation study was conducted using bench-top experiments at 38, 48, 55, 62.5, 70, and 78°C in mixed and non-mixed reactors using ground poultry carcasses as a feedstock. Subsequently, these observations were used for developing a non-linear model. The model predictions were compared with the observations of a different set of experiments. The comparisons among predictions and observations showed that the model predictions are reasonable and can be useful to determine the time required for Salmonella inactivation in poultry carcasses at multiple temperatures. Results showed that at composting conditions, when temperature varies between 48 and 62.5°C, Salmonella survival can prolong between 10,000 and 25,000 min (7 to 17 d). If ambient temperature is maintained at low temperature rendering range (70 to 78°C), then Salmonella survival can last for 90 to 120 minutes. We anticipate that this study will help in improving the existing understanding of Salmonella survival in poultry carcasses.

Modeling the long-term kinetics of Salmonella survival on dry pet food

Due to multiple outbreaks and large-scale product recalls, Salmonella has emerged as a priority pathogen in dry pet food and treats. However, little data are available to quantify risks posed by these classes of products to both pets and their owners. Specifically, the kinetics of Salmonella survival on complex pet food matrices are not available. This study measured the long-term kinetics of Salmonella survival on a dry pet food under storage conditions commonly encountered during production, retail, and in households (aw < 0.60, 23 °C). A Salmonella enterica cocktail of 12 strains isolated from dry pet foods and treats was used to inoculate commercial dry dog food. Salmonella was enumerated on non-selective (BHI) and selective (XLD and BS) media. Results at 570 days indicated an initial relatively rapid decline (up to 54 days), followed by a much slower extended decline phase. The Weibull model provided a satisfactory fit for time series of Log-transformed Salmonella counts from all three media (δ: mean 4.65 day/Log (CFU/g); p: mean 0.364 on BHI). This study provides a survival model that can be applied in quantitative risk assessment models.