Evaluation of the association between feeding raw meat and Salmonella enterica infections at a Greyhound breeding facility.

OBJECTIVE: To investigate Salmonella enterica infections at a Greyhound breeding facility. DESIGN: Cross-sectional study. ANIMAL AND SAMPLE POPULATIONS: 138 adult and juvenile dogs and S. enterica isolates recovered from the dogs and their environment. PROCEDURES: The investigation was conducted at the request of a Greyhound breeder. Observations regarding the environment and population of dogs were recorded. Fecal, food, and environmental specimens were collected and submitted for Salmonella culture. Isolates were serotyped and tested for susceptibility to 16 antimicrobials. Isolates underwent genetic analyses by use of pulsed-field gel electrophoresis and ribotyping. RESULTS: S. enterica was recovered from 88 of 133 (66%) samples of all types and from 57 of 61 (93%) fecal samples. Eighty-three (94.3%) of the isolates were serotype Newport, 77 (87.5%) of which had identical resistance phenotypes. Genetic evaluations suggested that several strains of S. enterica existed at the facility, but there was a high degree of relatedness among many of the Newport isolates. Multiple strains of Salmonella enterica serotype Newport were recovered from raw meat fed on 1 day. CONCLUSIONS AND CLINICAL RELEVANCE: S. enterica infections and environmental contamination were common at this facility. A portion of the Salmonella strains detected on the premises was likely introduced via raw meat that was the primary dietary constituent. Some strains appeared to be widely disseminated in the population. Feeding meat that had not been cooked properly, particularly meat classified as unfit for human consumption, likely contributed to the infections in these dogs.

Evaluation of bacterial and protozoal contamination of commercially available raw meat diets for dogs.

OBJECTIVE: To evaluate bacterial and protozoal contamination of commercially available raw meat diets for dogs. DESIGN: Prospective longitudinal study. SAMPLE POPULATION: 240 samples from 20 raw meat diets for dogs (containing beef, lamb, chicken, or turkey), 24 samples from 2 dry dog foods, and 24 samples from 2 canned dog foods. PROCEDURE: Each product was purchased commercially on 4 dates approximately 2 months apart. Three samples from each product at each sampling period were evaluated via bacterial culture for non-type-specific Escherichia coli (NTSEC), Salmonella enterica, and Campylobacter spp. Antimicrobial susceptibility testing was performed on selected isolates. Polymerase chain reaction assays were used to detect DNA from Cryptosporidium spp, Neospora spp, and Toxoplasma spp in samples obtained in the third and fourth sampling periods. RESULTS: One hundred fifty-three of 288 (53%) samples were contaminated with NTSEC. Both raw and prepared foods contained NTSEC during at least 1 culture period. Salmonella enterica was recovered from 17 (5.9%) samples, all of which were raw meat products. Campylobacter spp was not isolated from any samples. In 91 of 288 (31.6%) samples, there was no gram-negative bacterial growth before enrichment and in 48 of 288 (16.7%) samples, there was no aerobic bacterial growth before enrichment. Susceptibility phenotypes were variable. Cryptosporidium spp DNA was detected in 3 samples. CONCLUSIONS AND CLINICAL RELEVANCE: Bacterial contamination is common in commercially available raw meat diets, suggesting that there is a risk of foodborne illness in dogs fed these diets as well possible risk for humans associated with the dogs or their environments.

Characterization of Escherichia coli and Salmonella enterica from cattle feed ingredients.

The objectives of this study were (1) to evaluate the frequency with which feed ingredients or mixed feeds in cattle feedlots were contaminated with Escherichia coli and Salmonella spp. and (2) to evaluate the antimicrobial susceptibility patterns of non-type-specific Escherichia coli and Salmonella spp. recovered from feed ingredients or mixed feeds. Approximately 30 individual samples were collected from each of several feed commodities present on two cattle feedlots each month for 1 year. Half of the samples were cultured for Escherichia coli, and the other half were cultured for Salmonella spp. E. coli was recovered from 48.2% (516/1070) of the samples and from all feed ingredient types at least once. Salmonella spp. were recovered from 5.3% (57/1070) of samples. Overall, 40.3% (207/514) of E. coli isolates and 54.4% (31/57) of Salmonella spp. isolates were susceptible to all antimicrobials tested in the panel. Bacterial contamination of feed ingredients used at cattle feedlots with enteric bacteria is relatively common. In some cases, the enteric organisms are resistant to one or more antimicrobials. Feed ingredients may be a source of genetic elements associated with antimicrobial resistance for feedlot cattle. To be successful in minimizing foodborne pathogens and antimicrobial resistance in the cattle feedlot setting, it is important to consider the myriad of potential sources of these organisms or genetic elements.