Evidence that faecal carriage of resistant Escherichia coli by 16-week-old dogs in the United Kingdom is associated with raw feeding

Preparation of Fecal Microbiota Transplantation Products for Companion Animals

Fecal microbiota transplantation (FMT) is increasingly utilized in small animal medicine for the treatment of a variety of gastrointestinal and non-gastrointestinal disorders. Despite proven clinical efficacy, there is no detailed protocol available for the preparation and storage of FMT products for veterinarians in a variety of clinical settings. Herein, the effect of processing technique on the microbial community structure was assessed with amplicon sequence analysis. Microbial viability was assessed with standard culture techniques using selective media. Given the fastidious nature of many intestinal microbes, colony forming units are considered surrogate viable microbes, representing a portion of potentially viable microbes. FMT products from four screened canine fecal donors and six screened feline fecal donors were processed aerobically according to a double centrifugation protocol adapted from the human medical literature. Fresh feces from an additional three screened canine fecal donors were used to evaluate the effect of cryopreservative, centrifugation, and short-term storage on microbial community structure and in vitro surrogate bacterial viability. Finally, fresh feces from a third group of three screened canine and three screened feline fecal donors were used to evaluate the long-term in vitro surrogate bacterial viability of three frozen and lyophilized FMT products. Microbiota analysis revealed that each canine fecal donor has a unique microbial profile. Processing of canine and feline feces for FMT does not significantly alter the overall microbial community structure. The addition of cryopreservatives and lyopreservatives significantly improved long-term viability, up to 6 months, for frozen and lyophilized FMT products compared to unprocessed raw feces with no cryopreservative. These results prove the practicality of this approach for FMT preparation in veterinary medicine and provide a detailed protocol for researchers and companion animal practitioners. Future in vivo research is needed to evaluate how the preparation and microbial viability of FMT impacts the recipient's microbial community and clinical outcomes across multiple disease phenotypes.

Current Evidence on Raw Meat Diets in Pets: A Natural Symbol, but a Nutritional Controversy

Feeding raw meat to cats and dogs has become a common practice in Western countries. Many pet owners cite their pets' wild carnivore ancestry and believe raw meat diets are healthier, citing higher nutritional value, a lack of processing, low-carbohydrate content, and/or the presence of whole ingredients. However, due to the risks associated with raw meat-based diets (e.g., microbial contamination, nutritional imbalances) and growing concerns about food sustainability, most nutritional specialists and public health stakeholders question the practice of feeding raw meat. In this context, the vast majority of owners' claims regarding the beneficial health effects of raw meat diets lack scientific substantiation, while professional advice primarily focuses on risks, often overlooking potential positive health effects. To better understand the effects of raw meat diets on the health of cats and dogs, this review summarises the latest scientific evidence and discusses both the potential health benefits and the risks associated with these diets.

Risk factors for antimicrobial-resistant Enterobacterales in dogs: a systematic review

Identifying risk factors associated with the carriage of antimicrobial-resistant (AMR) bacteria in dogs is crucial to understanding their epidemiology and for developing and refining targeted control measures. However, relevant data is scattered and conflicting findings have been reported. This systematic review aimed to compile risk factors associated with the carriage of AMR-Enterobacterales in dogs worldwide and to identify relevant knowledge gaps for directing future research. A systematic review was conducted according to PRISMA guidelines, searching PubMed, CABi, and Scopus databases for studies reporting risk factors for acquiring AMR-Enterobacterales in dogs. After screening peer-reviewed, English-language studies by title/abstract, eligible studies were subjected to a full-text assessment, data extraction, risk-of-bias assessment, and qualitative synthesis. In the initial search, 774 articles were identified, including 274 duplicates. After screening by title/abstract, 77 articles were subjected to full-text review, from which 40 were eventually selected for data extraction, including 29 cross-sectional, six cohort, and five case-control studies. The most frequently investigated risk factors for AMR-Enterobacterales carriage in dogs were antimicrobial use (28 of 40), age (24), sex (22), hospitalization (19), and feeding raw diet (14). Of these, antimicrobial use was the most common risk factor significantly associated with AMR-Enterobacterales (19/28), followed by raw diet (9/14) and hospitalization (8/19). Our synthesis emphasized the importance of increasing awareness regarding the prudent use of critically important antimicrobials (CIAs), such as fluoroquinolones, in companion animal practices, strengthening infection prevention and control procedures in veterinary clinics and hospitals and educating caregivers about the potential risks of feeding raw diets in order to reduce the burden of AMR-bacteria in dogs.

Raw meat diets are a major risk factor for carriage of third-generation cephalosporin-resistant and multidrug-resistant E. coli by dogs in the UK

Introduction

Raw-meat diets (RMD) for dogs, comprising unprocessed or non-heat-treated animal material, are increasingly popular. However, RMDs have been demonstrated to be contaminated with antimicrobial resistant (AMR) bacteria, and there is concern that such diets may pose a zoonotic disease risk. Additionally, dogs fed RMD may shed more AMR- fecal bacteria compared to those fed conventional cooked diets. Data from the UK remain limited; the present study investigated the presence of AMR-Escherichia coli in the feces of RMD and non-RMD (NRMD)-fed dogs in the UK, the E. coli AMR gene complement, and the lifestyle risk factors associated with AMR- E. coli carriage.

Methods

Fecal samples from UK-owned dogs (N = 193 RMD, N = 239 NRMD) and questionnaires discussing lifestyle factors, were obtained between October 2020-August 2021. Samples underwent culture and antimicrobial susceptibility testing to determine the presence of AMR-E. coli. Whole genome sequencing determined AMR gene carriage. Risk factors for the presence of AMR-E. coli were determined by multivariable modeling.

Results

RMD dogs carried significantly more fecal AMR E. coli (p < 0.001), including third-generation cephalosporin resistant, extended-spectrum beta-lactamase (ESBL) producing, and multidrug resistant isolates and multivariable modeling confirmed raw-meat diets to be a significant risk factor. The bla CTX-M-15 gene was the most frequently identified bla ESBL gene. The bla CTX-M-55 and bla SHV-66 genes were also prevalent and were only found in RMD dogs. The mobile colistin resistance gene, mcr-4 was identified in one ESBL-producing E. coli isolate from a NRMD-fed dog.

Conclusion

This study has shown that dogs fed RMD in the UK are significantly more likely to shed E. coli which is resistant to highest priority critically important antibiotics, and multidrug resistant E. coli, than dogs fed NRMD. Additionally, AMR-E. coli isolates from RMD-fed dogs harbor multiple, diverse, and novel AMR genes. Therefore, provision of RMD to dogs could pose an important potential threat to human and animal health, especially given the close nature of the relationship many owners share with their pets. Awareness of these findings should be shared with pet owners, veterinary and medical professionals, pet food manufacturers and public health to mitigate potential risks.

Comprehensive profile of the companion animal gut microbiome integrating reference-based and reference-free methods

The gut microbiome of companion animals is relatively underexplored, despite its relevance to animal health, pet owner health, and basic microbial community biology. Here, we provide the most comprehensive analysis of the canine and feline gut microbiomes to date, incorporating 2639 stool shotgun metagenomes (2272 dog and 367 cat) spanning 14 publicly available datasets (n = 730) and 8 new study populations (n = 1909). These are compared with 238 and 112 baseline human gut metagenomes from the Human Microbiome Project 1-II and a traditionally living Malagasy cohort, respectively, processed in a manner identical to the animal metagenomes. All microbiomes were characterized using reference-based taxonomic and functional profiling, as well as de novo assembly yielding metagenomic assembled genomes clustered into species-level genome bins. Companion animals shared 184 species-level genome bins not found in humans, whereas 198 were found in all three hosts. We applied novel methodology to distinguish strains of these shared organisms either transferred or unique to host species, with phylogenetic patterns suggesting host-specific adaptation of microbial lineages. This corresponded with functional divergence of these lineages by host (e.g. differences in metabolic and antibiotic resistance genes) likely important to companion animal health. This study provides the largest resource to date of companion animal gut metagenomes and greatly contributes to our understanding of the "One Health" concept of a shared microbial environment among humans and companion animals, affecting infectious diseases, immune response, and specific genetic elements.

One health transmission of fluoroquinolone-resistant Escherichia coli and risk factors for their excretion by dogs living in urban and nearby rural settings

Rates of fluoroquinolone resistance in Escherichia coli, a key opportunistic human pathogen, are problematic. Taking a One Health approach, we investigated the excretion of fluoroquinolone-resistant (FQ-R) E. coli by 600 dogs (303 from rural and 297 from urban environments) recruited from a 50 × 50 km region where we have also surveyed FQ-R E. coli from cattle and from human urine. FQ-R E. coli were detected in faeces from 7.3% (rural) and 11.8% (urban) of dogs. FQ-R E. coli from rural dogs tended to be of sequence types (STs) commonly excreted by cattle, whilst those from urban dogs tended to carry plasmid-mediated quinolone resistance genes, common in human E. coli in our study region. Phylogenetic evidence was obtained for sharing FQ-R E. coli - particularly for STs 10, 162 and 744 - between cattle, dogs and humans. Epidemiological analysis showed a strong association between feeding dogs uncooked meat and the excretion of FQ-R E. coli, particularly for STs 10, 162 and 744. This practice, therefore, could serve as a transmission link for FQ-R E. coli from farmed animals entering the home so we suggest that dogs fed uncooked meat should be handled and housed using enhanced hygiene practices.

Molecular ecology of highest priority critically important antibiotic resistant Escherichia coli from mammals housed at an urban zoo

OBJECTIVES

Zoos are environments where species of highly valued animals are kept largely separated from others and the wider world. We report the molecular ecology of critically important antibiotic resistant (ABR) Escherichia coli carried by 28 mammalian species housed in a zoo located in an urban residential district.

METHODS

Over 3 months we collected 167 faecal samples from captive mammals and processed for E. coli resistant to third-generation cephalosporins (3GC-R) and fluoroquinolones (FQ-R). Isolates were sequenced using Illumina.

RESULTS

We identified high rates of faecal sample-level positivity, with 50%, 57% and 36% of mammalian species excreting 3GC-R, FQ-R or dual 3GC-R/FQ-R E. coli, respectively. Isolates represented multiple ST and ABR mechanisms; CTX-M-15 and CMY-2 dominated for 3GC-R, and target-site mutation caused 75% of FQ-R. We identified multiple examples of ABR E. coli transmission between mammalian species in separate enclosures, and a variant of the epidemic plasmid pCT within the zoo. There was no evidence for ABR E. coli leaving the zoo, based on comparative analysis with E. coli from humans, cattle and dogs isolated from the 50 × 50 km region in which the zoo is located. Amoxicillin/clavulanate was the most widely used antibiotic in the zoo, and we identified four widely disseminated amoxicillin/clavulanate resistance mechanisms, including a previously unreported inhibitor-resistant TEM, and the carbapenemase OXA-181.

CONCLUSIONS

We conclude that the zoo studied here is a 'melting pot' for the selection and circulation of 3GC-R and FQ-R E. coli, but these circulating E. coli appear captive within the zoo.

Molecular ecology and risk factors for third-generation cephalosporin-resistant Escherichia coli carriage by dogs living in urban and nearby rural settings

Objectives

To compare faecal third-generation cephalosporin-resistant (3GC-R) Escherichia coli isolates from dogs living in a city and in a rural area ∼30 km away; to compare isolates from dogs, cattle and humans in these regions; and to determine risk factors associated with 3GC-R E. coli carriage in these two cohorts of dogs.

Methods

Six hundred dogs were included, with faecal samples processed to recover 3GC-R E. coli using 2 mg/L cefotaxime. WGS was by Illumina and risk factor analyses were by multivariable linear regression using the results of an owner-completed survey.

Results

3GC-R E. coli were excreted by 20/303 rural and 31/297 urban dogs. The dominant canine 3GC-R ST was ST963 (bla_CMY-2), which also accounted for 25% of CMY-2-producing E. coli in humans. Phylogenetic overlap between cattle and rural dog CTX-M-14-producing E. coli ST117 was observed as well as acquisition of pMOO-32-positive E. coli ST10 by a rural dog, a plasmid common on cattle farms in the area. Feeding raw meat was associated with carrying 3GC-R E. coli in rural dogs, but not in urban dogs, where swimming in rivers was a weak risk factor.

Conclusions

Given clear zoonotic potential for resistant canine E. coli, our work suggests interventions that may reduce this threat. In rural dogs, carriage of 3GC-R E. coli, particularly CTX-M producers, was phylogenetically associated with interaction with local cattle and epidemiologically associated with feeding raw meat. In urban dogs, sources of 3GC-R E. coli appear to be more varied and include environments such as rivers.

Understanding the dog population in the Republic of Ireland: insight from existing data sources?

Background

Reliable information about national pet dog populations is an important contributor to informed decision-making, both by governments and national dog welfare organisations. In some countries, there is an improved understanding of aspects of the national pet dog population, but as yet limited published information is available in Ireland. The current study reviews the utility of existing data to inform our understanding of recent changes to the pet dog population in Ireland, including both biological and organisational processes.

Results

Based on national data on dog licencing and microchipping registration, pet dog numbers have remained relatively stable in recent years (ie prior to the COVID-19 pandemic). Since 2015, there has been a substantial decrease in the number of dogs managed through dog control centres. Although the completeness of the data are likely variable, there appears to be substantial, and increasing, number of dogs moving from Ireland to other countries, including UK, Sweden, Italy, Germany and Singapore. We also note an increase (albeit much smaller) in the number of dogs being moved into Ireland.

Conclusions

This study highlights the challenges faced when using existing national data to gain insights into the dog population of Ireland. The linking of existing national databases (individual dog identification, dog licencing, dog control statistics) has the potential to improve both the representativeness and accuracy of information about the Irish pet dog population. In the next phases of our work, we will focus on the work of dog welfare organisations, given both the increased role played by these organisations and the substantial public funding that has been committed in this sector.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13620-022-00223-8.