Prevalence and shedding patterns of Campylobacter spp. in longitudinal studies of kennelled dogs

Prevalence and antimicrobial resistance of Campylobacter species in shelter-housed healthy and diarrheic cats and dogs in Turkey

BACKGROUND

Campylobacter spp. are among the leading foodborne bacterial pathogens. Pet animals may be an important reservoir for human infection.

OBJECTIVES

To determine the prevalence and antimicrobial resistance profiles and mechanisms of Campylobacter isolates recovered from shelter-housed healthy and diarrheic cats and dogs in Erzurum province in Turkey.

METHODS

A total of 250 rectal swabs (from 124 cats and 126 dogs) collected between 2020 and 2021 were included in this study. The samples were cultured using a Campylobacter-selective agar medium. A single suspect colony from each plate was purified and species identification was performed by PCR. Minimum inhibitory concentration (MIC) values were determined against eight antibiotics. Specific antimicrobial resistance genes (tetO and aphA-3) and mutations (in gyrA) were screened by PCR and/or sequencing.

RESULTS

A total of 26 (10.4%) isolates (25 Campylobacter jejuni and 1 Campylobacter coli) were obtained from the dogs; no Campylobacter was isolated from the cats. Of the C. jejuni isolates, 19.2% were resistant to nalidixic acid, 7.7% to ciprofloxacin and 3.8% to tetracycline and gentamicin per the CLSI interpretative criteria. The C. coli isolate was susceptible to all of the tested antibiotics. Thr-86-Ile mutation was the most common change detected in the gyrA gene in the quinolone-resistant isolates.

CONCLUSION

While geographic and population differences exist, Campylobacter carriage and associated antibiotic resistance in dogs is common, emphasising the need for continuous surveillance in this species, particularly given its zoonotic potential.

Probabilistic fecal pollution source profiling and microbial source tracking for an urban river catchment

We developed an innovative approach to estimate the occurrence and extent of fecal pollution sources for urban river catchments. The methodology consists of 1) catchment surveys complemented by literature data where needed for probabilistic estimates of daily produced fecal indicator (FIBs, E. coli, enterococci) and zoonotic reference pathogen numbers (Campylobacter, Cryptosporidium and Giardia) excreted by human and animal sources in a river catchment, 2) generating a hypothesis about the dominant sources of fecal pollution and selecting a source targeted monitoring design, and 3) verifying the results by comparing measured concentrations of the informed choice of parameters (i.e. chemical tracers, C. perfringensspores, and host-associated genetic microbial source tracking (MST) markers) in the river, and by multi-parametric correlation analysis. We tested the approach at a study area in Vienna, Austria. The daily produced microbial particle numbers according to the probabilistic estimates indicated that, for the dry weather scenario, the discharge of treated wastewater (WWTP) was the primary contributor to fecal pollution. For the wet weather scenario, 80-99 % of the daily produced FIBs and pathogens resulted from combined sewer overflows (CSOs) according to the probabilistic estimates. When testing our hypothesis in the river, the measured concentrations of the human genetic fecal marker were log₁₀ 4 higher than for selected animal genetic fecal markers. Our analyses showed for the first-time statistical relationships between C. perfringens spores (used as conservative microbial tracer for communal sewage) and a human genetic fecal marker (i.e. HF183/BacR287) with the reference pathogen Giardia in river water (Spearman rank correlation: 0.78-0.83, p < 0.05. The developed approach facilitates urban water safety management and provides a robust basis for microbial fate and transport models and microbial infection risk assessment.

Dogs and Cats: Reservoirs for Highly Diverse Campylobacter jejuni and a Potential Source of Human Exposure

Assessing the carriage of Campylobacter in animal reservoirs is essential to better understand Campylobacter epidemiology. Here, we evaluated the prevalence of thermophilic Campylobacter spp. in dogs and cats, hereafter defined as pets, and characterized Campylobacter jejuni (C. jejuni) isolates to assess their genetic diversity and their potential link with isolates from other animals or human cases. During a 6-month period, 304 feces samples were collected from pets. A significantly higher prevalence of thermophilic Campylobacter spp. was found in dogs compared with cats, as well as in dogs ≤ 1-year-old compared with older dogs. C. jejuni was the predominant species found in pets, and its genomic characterization revealed a high genetic diversity. Genotypes comparison with previously characterized isolates revealed a partial overlap between C. jejuni isolates from pets, chicken, cattle, and clinical cases. This overlap suggests the potential role of livestock and humans in pets' exposure to Campylobacter, or vice versa. The isolation of pets' specific profiles may suggest the existence of other sources of pet contamination or imply that pets may constitute a reservoir for Campylobacter. Because of the proximity between humans and pets, along with their frequent carriage of C. jejuni, human exposure to Campylobacter from pets can be more important than previously thought.

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

There is a recent trend to feed pet dogs and cats in Britain and other developed countries on raw meat and animal by-products using either commercial preparations or home recipes. This shift from heat-treated processed food has been driven by perceived health benefits to pets and a suspicion of industrially produced pet food. The diets of wild-living related species have been used as a rationale for raw feeding, but differences in biology and lifestyle impose limitations on such comparisons. Formal evidence does exist for claims by raw-feeding proponents of an altered intestinal microbiome and (subjectively) improved stool quality. However, there is currently neither robust evidence nor identified plausible mechanisms for many of the wide range of other claimed benefits. There are documented risks associated with raw feeding, principally malnutrition (inexpert formulation and testing of diets) and infection affecting pets and/or household members. Surveys in Europe and North America have consistently found Salmonella species in a proportion of samples, typically of fresh-frozen commercial diets. Another emerging issue concerns the risk of introducing antimicrobial-resistant bacteria. Raw pet food commonly exceeds hygiene thresholds for counts of Enterobacteriaceae. These bacteria often encode resistance to critically important antibiotics such as extended-spectrum cephalosporins, and raw-fed pets create an elevated risk of shedding such resistant bacteria. Other infectious organisms that may be of concern include Listeria, shiga toxigenic E scherichia coli , parasites such as Toxoplasma gondii and exotic agents such as the zoonotic livestock pathogen Brucella suis, recently identified in European Union and UK raw pet meat imported from Argentina.

Prevalence and risk factors associated with Campylobacter spp. occurrence in healthy dogs visiting four rural community veterinary clinics in South Africa

Reports on the occurrence of Campylobacter spp. in dogs in South Africa are non-existent. This study investigated the prevalence of Campylobacter spp. in 481 dogs visiting four rural community veterinary clinics in South Africa. Dogs were screened for Campylobacter spp. by culture and polymerase chain reaction (PCR), and logistic regression analysis was performed to assess the association between sex, clinic, breed and age and the occurrence of Campylobacter spp. in dogs. The prevalence of Campylobacter spp. was 41.50% (95% confidence interval [CI], 37.39% - 46.04%). Campylobacter jejuni, C. upsaliensis and C. coli were detected in 29.31% (95% CI, 25.42% - 33.54%), 13.10% (95% CI, 10.37% - 16.42%) and 5.41% (95% CI, 3.71% - 7.82%) of dogs, respectively. Dogs carrying more than one species of Campylobacter spp. accounted for 6.23% (95% CI, 4.40% - 8.78%). Campylobacter upsaliensis and C. jejuni were detected in 3.74% (95% CI, 2.37% - 5.86%), whereas C. coli and C. jejuni were found in 2.49% (95% CI, 1.42% - 4.34%) of dogs. Age and clinic were the risk factors significantly associated with Campylobacter spp. occurrence, while age, breed and clinic were predictors of C. jejuni carriage. Furthermore, age was the only risk factor associated with a higher likelihood of carrying C. upsaliensis. The prevalence of Campylobacter spp. C. jejuni and C. upsaliensis increased significantly as dogs grew older. In addition, the odds of carrying Campylobacter spp. were higher in the Staffordshire bull terrier breed compared to crossbreed dogs. In conclusion, this study shows that dogs visiting rural community veterinary clinics in South Africa are reservoirs of Campylobacter spp. and may be potential sources of Campylobacter spp. for humans living in close proximity of the dog populations under study.

Prevalence of most common human pathogenic Campylobacter spp. in dogs and cats in Styria, Austria

The aim of this study was to determine the frequency of occurrence of most common human pathogenic Campylobacter species, Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli), in dogs and cats in Styria, Austria. In the period from April 2010 to April 2012, 842 faecal samples from dogs and cats from Styria, Austria were examined for Campylobacter (C.) species (spp.). All samples were subjected to qualitative microbiological culture testing, and additionally, some of them have been studied using qualitative real‐time PCR. In microbiological culture, 5.9% of all samples investigated were C. spp. positive. With 3.1% out of positive samples, C. jejuni was the most common type. Campylobacter upsaliensis (C. upsaliensis) was detected only in 0.5% of the samples. The remaining positive samples (2.4%) were classified as C. species (sp.). C. coli could not be found in any of the samples. A higher prevalence of C. jejuni was found in kittens with 14.3% and in diarrhoeic dogs (7.4%) and cats (23.8%). The real‐time PCR revealed for dogs and cats together, 27% of C. jejuni‐positive faecal and 8% positive faecal swap samples. The obtained C. jejuni strains underwent antibiotic resistance testing using three different tests (agar diffusion, MIC testing and E‐test) with different numbers of antibiotics. From the antibiotics used in this study, several showed high test‐dependent resistance rates (cephalexin, cefovecin, kanamycin, sulfamethoxazole/trimethoprim, penicillin G, ciprofloxacin, enrofloxacin, marbofloxacin, nalidixic acid). Overall, the prevalence of C. spp. in this study was very low compared to others, with the exception of C. jejuni in kittens and diarrhoeic animals. The results of the real‐time PCR suggest that the rate of colonization of C. jejuni was actually higher than the results of the culture showed. As the resistance rates of C. jejuni isolates partly were very high, possible transmission of (multi‐) resistant C. jejuni strains to humans especially from kittens and diarrhoeic animals must be expected.

Raw Meat-Based Diets in Dogs and Cats

Feeding pets raw meat-based diets (RMBDs) is commonly practiced by many companion animal owners and has received increasing attention in recent years. It may be beneficial for the animals, but may also pose a health risk for both pets and their owners, as RMBDs may be contaminated by enteric pathogens-such as Campylobacter, Salmonella, and Yersinia-which are the most common zoonotic bacteria causing enteritis in humans. Little information exists on the prevalence of these pathogens in pet food, and thus one aim was to investigate the prevalence of Campylobacter, Salmonella, and Yersinia in commercial RMBDs from retail stores. Little evidence also exists on the significance of raw meat feeding on the shedding of Campylobacter, Salmonella, and enteropathogenic Yersinia in the feces of pets, and therefore, the second goal was to study the presence of these pathogens in dogs and cats fed RMBDs. Polymerase chain reaction (PCR) only sporadically detected Campylobacter, Salmonella, and enteropathogenic Yersinia in RMBDs. These pathogens were not found by culturing, indicating a low contamination level in frozen RMBDs. They were also detected in the feces of dogs and cats, but the association with feeding RMBDs to them remained unclear.

Prevalence of thermophilic Campylobacter species in Swedish dogs and characterization of C. jejuni isolates

BACKGROUND

The aims of this study were to investigate the prevalence of Campylobacter species in Swedish dogs, to identify the species of the Campylobacter isolates and to genotype the C. jejuni isolates. Young and healthy dogs were targeted and the sampling was performed at 11 veterinary clinics throughout Sweden from October 2011 to October 2012. Faecal swab samples were collected and sent to the laboratory at the National Veterinary Institute (SVA) for isolation of Campylobacter, speciation and genotyping.

RESULTS

Campylobacter spp. were isolated from 67 of the 180 sampled dogs which yields an overall prevalence of 37%. The most prevalent species of Campylobacter among the participating dogs was C. upsaliensis with 52 of the 67 identified isolates. A lower prevalence was observed for C. jejuni with seven identified isolates and one isolate was identified as C. helveticus. Multi-locus sequence typing (MLST) was carried out on the seven C. jejuni isolates and all sequence types that were found are also commonly found in humans. The dogs were divided into three age groups; 1) under 12 months, 2) 12 to 23 months and 3) 24 months and older. The highest prevalence was found in the two younger age groups. Dogs shedding C. jejuni were between 3-12 months of age while dogs shedding C. upsaliensis were found in all ages.

CONCLUSIONS

The present investigation finds that Campylobacter spp. known to cause campylobacteriosis in humans are present in Swedish dogs. The results suggest an age predisposition where dogs under 2 years of age are more likely to shed Campylobacter spp. than older dogs. The most commonly isolated species was C. upsaliensis followed by C. jejuni, which was only detected in dogs up to 12 months of age. All C. jejuni isolates identified in the present study were of the same MLST types that have previously been described both in humans and in animals. The awareness of the Campylobacter risk of healthy young dogs may be an important way to reduce the transmission from dogs to infants, young children and immunocompromised adults.

Occurrence and characterization of Campylobacter spp.isolates in dogs, cats and children

To improve the understanding of implications of Campylobacterspp. infections in pets and children of different environments were analysed 160 faecal samples from children and 120 from pets (103 dogs and 17 cats). Campylobacter spp. were detected in 6.87% of the children and in 18.3% of the dogs and cats. From 33 stool samples positive for Campylobacter spp., 57.6% were identified as C. jejuni, and 33.4% were identified as C. coli. More than 50% of the isolates in pets were resistant to ceftiofur, sulphazotrim, norfloxacin and tetracycline. In humans, most of the isolates were resistant to amoxicillin, cefazolin, ceftiofur, erythromycin and norfloxacin. From 19 isolates of C. jejuni, 11 isolates from children and 5 from dogs contained two to four of the virulence genes flaA, pldA, cadF or ciaB.We found an association between the presence of virulence genes and diarrhoea. Furthermore, an association was observed between the presence of Campylobacter spp. and diarrhoea in dewormed pets with blood picture suggestive of bacterial infection, and the therapeutic use of antibiotics was associated with more positive detection of Campylobacterspp. in the faeces of pets. Our data indicate that virulent strains of Campylobacter spp. can be risk factor to diarrhoea in animals, and that high resistance to antimicrobial agents is common in pets.

Survey of Campylobacter spp. in owned and unowned dogs and cats in Northern Italy

Campylobacteriosis is among the most common bacterial causes of human gastroenteritis worldwide and pet ownership has been identified as a risk factor for Campylobacter infection in humans. Since canine and feline prevalence data are scarce in Italy, the present study was carried out to assess the prevalence, species distribution and risk factors for Campylobacter infection in dogs and cats under different husbandry conditions. Rectal swabs were collected from 171 dogs (household pets, n = 100; shelter-housed dogs, n = 50; dogs from breeding kennels, n = 21) and 102 cats (household pets, n = 52; shelter-housed cats, n = 21; free-roaming cats n = 29) in Northern Italy. Campylobacter was isolated from 17% (n = 29) of dogs and 14.7% (n = 15) of cats. C. jejuni was the most common isolate in both species (Campylobacter spp.-positive dogs, 55.2%; Campylobacter spp.-positive cats, 53.3%), followed by C. upsaliensis (Campylobacter spp.-positive dogs, 27.6%; Campylobacter spp.-positive cats, 40%). Other Campylobacter species were rarely detected, but included C. hyointestinalis subsp. hyointestinalis, C. lari and C. coli in dogs and C. coli and C. helveticus in cats. Among considered variables (sex, age, origin, diarrhoea, season of sampling), origin was identified as a risk factor for dogs, with shelter-housed dogs at higher risk than household dogs (odds ratio, 2.84; 95% CI 1.17, 6.92; P = 0.021). The results of this study, particularly the high prevalence of C. jejuni in Campylobacter-positive animals, demonstrated that household and stray dogs and cats in Northern Italy might pose a zoonotic risk for humans. Moreover, biosecurity measures should be improved in dog shelters.

The clinical importance of emerging Campylobacter species

A growing number of Campylobacter species other than C. jejuni and C. coli have been recognized as emerging human and animal pathogens. Although C. jejuni continues to be the leading cause of bacterial gastroenteritis in humans worldwide, advances in molecular biology and development of innovative culture methodologies have led to the detection and isolation of a range of under-recognized and nutritionally fastidious Campylobacter spp., including C. concisus, C. upsaliensis and C. ureolyticus. These emerging Campylobacter spp. have been associated with a range of gastrointestinal diseases, particularly gastroenteritis, IBD and periodontitis. In some instances, infection of the gastrointestinal tract by these bacteria can progress to life-threatening extragastrointestinal diseases. Studies have shown that several emerging Campylobacter spp. have the ability to attach to and invade human intestinal epithelial cells and macrophages, damage intestinal barrier integrity, secrete toxins and strategically evade host immune responses. Members of the Campylobacter genus naturally colonize a wide range of hosts (including pets, farm animals and wild animals) and are frequently found in contaminated food products, which indicates that these bacteria are at risk of zoonotic transmission to humans. This Review presents the latest information on the role and clinical importance of emerging Campylobacter spp. in gastrointestinal health and disease.