Population Genetics and Antimicrobial Susceptibility of Canine Campylobacter Isolates Collected before and after a Raw Feeding Experiment

Abstract

In recent years, increasing numbers of consumers have become interested in feeding raw food for their pet dogs as opposed to commercial dry food, in the belief of health advantages. However, raw meat and internal organs, possibly contaminated by pathogens such as Campylobacter spp., may pose a risk of transmission of zoonoses to the pet owners. Campylobacter jejuni is the leading cause of bacterial gastroenteritis in humans but C. upsaliensis has also been associated with human disease. In this study we investigated the effect of different feeding strategies on the prevalence of Campylobacter spp. in Finnish dogs. We further characterized the isolates using multilocus sequence typing (MLST), whole-genome (wg) MLST and antimicrobial susceptibility testing. Dogs were sampled before and after a feeding period consisting of commercial raw feed or dry pellet feed. Altogether 56% (20/36) of the dogs yielded at least one Campylobacter-positive fecal sample. C. upsaliensis was the major species detected from 39% of the dogs before and 30% after the feeding period. Two C. jejuni isolates were recovered, both from raw-fed dogs after the dietary regimen. The isolates represented the same genotype (ST-1326), suggesting a common infection source. However, no statistically significant correlation was found between the feeding strategies and Campylobacter spp. carriage. The global genealogy of MLST types of dog and human C. upsaliensis isolates revealed weakly clonal population structure as most STs were widely dispersed. Major antimicrobial resistance among C. upsaliensis isolates was against streptomycin (STR MIC > 4mg/l). Apart from that, all isolates were highly susceptible against the antimicrobials tested. Mutations were found in the genes rpsL or rpsL and rsmG in streptomycin resistant isolates. In conclusion, increasing trend to feed dogs with raw meat warrants more studies to evaluate the risk associated with raw feeding of pets in transmission of zoonoses to humans.

The prevalence of virulence genes and multidrug resistance in thermophilic Campylobacter spp. isolated from dogs

“…12.6%. This result stood in opposition to our earlier studies [ 1 , 20 ] and research conducted by other authors [ 5 , 21 ]. Chaban et al [ 22 ] analysed a group ( n = 70) of healthy dogs and found bacteria of the Campylobacter genus in 58% of the samples.…”

Owners’ perception of acquiring infections through raw pet food: a comprehensive internet‐based survey

“…20 28-33 In addition, Listeria greyii has been found in a dry pet food. 20 One study reported no diference in the carriage of Campylobacter species in dogs fed either a raw or a dry diet, 34 and one study found Salmonella species in three dogs that had not been given raw food of any kind and found no Salmonella species in dogs fed raw foods (n=24). 35 In addition to Salmonella, diferent kinds of mycotoxins [36][37][38][39] have been found in heat-treated pet foods, causing health problems to the pets themselves.…”

Raw Meat-Based Diets in Dogs and Cats

“…Serotyping was done with commercial antisera (Denka Seikan, Japan). The presence of Campylobacter was studied by plating (1 g feces/1 mL 0.9% saline) on modified charcoal cefoperazone deoxycholate agar (mCCDA) with cefoperazone and amphotericin (Oxoid, Basingstoke, UK) and identification was done by gram staining and PCR according to Olkkola et al [ 28 ].…”

“…These pathogens are widespread in nature and found in the gastrointestinal tract of wild and domestic mammals and birds. They have also been reported in dogs and cats with and without diarrhea [ 14 , 16 , 28 ]. However, the reported prevalence rates vary highly between the studies ( Table 1 ).…”