The Roles ofClostridium difficileand EnterotoxigenicClostridium perfringensin Diarrhea in Dogs

Epizootic of enterocolitis and clostridial overgrowth in NSG and NSG-related mouse strains

While the immunodeficient status of NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) and NSG-related mice provides utility for numerous research models, it also results in increased susceptibility to opportunistic pathogens. Over a 9-week period, a high rate of mortality was reported in a housing room of NSG and NSG-related mice. Diagnostics were performed to determine the underlying etiopathogenesis. Mice submitted for evaluation included those found deceased (n = 2), cage mates of deceased mice with or without diarrhea (n = 17), and moribund mice (n = 8). Grossly, mice exhibited small intestinal and cecal dilation with abundant gas and/or digesta (n = 18), serosal hemorrhage and congestion (n = 6), or were grossly normal (n = 3). Histologically, there was erosive to ulcerative enterocolitis (n = 7) of the distal small and large intestine or widespread individual epithelial cell death with luminal sloughing (n = 13) and varying degrees of submucosal edema and mucosal hyperplasia. Cecal dysbiosis, a reduction in typical filamentous bacteria coupled with overgrowth of bacterial rods, was identified in 18 of 24 (75%) mice. Clostridium spp. and Paeniclostridium sordellii were identified in 13 of 23 (57%) and 7 of 23 (30%) mice, respectively. Clostridium perfringens (7 of 23, 30%) was isolated most frequently. Toxinotyping of C. perfringens positive mice (n = 2) identified C. perfringens type A. Luminal immunoreactivity to several clostridial species was identified within lesioned small intestine by immunohistochemistry. Clinicopathologic findings were thus associated with overgrowth of various clostridial species, though direct causality could not be ascribed. A diet shift preceding the mortality event may have contributed to loss of intestinal homeostasis.

Assessment of the content of macronutrients and microbiological safety of dry dog foods

In Europe, there are no legal regulations specifying maximum allowable limits for pathogenic bacteria or fungi and yeasts in dog food. For proximate composition, the European Pet Food Industry Federation (FEDIAF) nutritional guidelines provide minimum recommended levels for protein and fat only, not for other ingredients and no safe maximum levels. Therefore, the aim of this study was to evaluate the microbiological safety of 35 dry dog foods, taking into account the division into foods with grains as the main plant ingredient and those described as grain-free. We assumed that grain-included foods are more susceptible to the presence of the total number of aerobic bacteria. This parameter is an essential, hygienic criterion informing about the microbiological safety of the pet food. It also inform about the microbiological quality of the food ingredients used, the effectiveness of decontamination during the production process, sanitary and hygienic conditions during the acquisition, processing and marketing of pet food and its components. In the case of macronutrients, the results in some cases were multiples of the minimum recommended levels. The most important microorganisms that presence was found in the analyzed dog foods were indicator bacteria (E. coli and coliform bacteria, Clostridium perfringens), whose presence in feed constitutes microbiological contamination. They inform about sanitary and hygienic conditions during the production and storage of the pet food. The current guidelines recommend microbiological testing of food for the presence of Salmonella bacilli as the basic indicator for assessing the sanitary quality. No Salmonella spp. was detected in any of the foods. The remaining analyzed bacteria (Proteus spp., Enterococcus spp., Staphylococcus spp.) as well as molds and yeasts, were present in both grain-included and grain-free foods. The obtained results showed that in terms of microbiological safety, grain-included foods come out worse, because microorganisms were detected more frequently in this type of dry dog food.

Prevalence of Clostridioides difficile in dogs (Canis familiaris) with gastrointestinal disorders in Rio de Janeiro

Clostridioides difficile infections (CDI) have a high morbidity and mortality rate and have always been considered a nosocomial disease. Nonetheless, the number of cases of community-acquired CDI is increasing, and new evidence suggests additional C. difficile reservoirs exist. Pathogenic C. difficile strains have been found in livestock, domestic animals, and meat, so a zoonotic transmission has been proposed.

OBJECTIVE

The goal of this study was to isolate C. difficile strains in dogs at a veterinary clinic in Rio de Janeiro, Brazil, and characterize clinical and pathological findings associated with lower gastrointestinal tract disorders.

METHODS

Fifty stool samples and biopsy fragments from dogs were obtained and cultured in the CDBA selective medium. All suggestive C. difficile colonies were confirmed by MALDI-TOF MS and PCR (tpi gene). Vancomycin, metronidazole, moxifloxacin, erythromycin, and rifampicin were tested for antibiotic susceptibility. Biofilm, motility assays, and a PCR for the toxins (tcdA, tcdB, and cdtB), as well as ribotyping, were also performed.

RESULTS

Blood samples and colonic biopsy fragments were examined in C. difficile positive dogs. Ten animals (20%) tested positive for C. difficile by using stool samples, but not from biopsy fragments. Most C. difficile strains were toxigenic: six were A+B+ belonging to RT106; two were A+B+ belonging to RT014/020; and two were A-B- belonging to RT010. All strains were biofilm producers. In the motility test, 40% of strains were as motile as the positive control, CD630 (RT012). In the disc diffusion test, two strains (RT010) were resistant to erythromycin and metronidazole; and another to metronidazole (RT014/020). In terms of C. difficile clinicopathological correlations, no statistically significant morphological changes, such as pseudomembranous and "volcano" lesions, were observed. Regarding hematological data, dogs positive for C. difficile had leucopenia (p = 0.02) and lymphopenia (p = 0.03). There was a significant correlation between senility and the presence of C. difficile in the dogs studied (p = 0,02).

CONCLUSIONS

Although C. difficile has not been linked to canine diarrheal disorders, it appears to be more common in dogs with intestinal dysfunctions. The isolation of ribotypes frequently involved in human CDI outbreaks around the world supports the theory of C. difficile zoonotic transmission.

Molecular epidemiology of Clostridioides difficile in companion animals: Genetic overlap with human strains and public health concerns

Introduction

The changing epidemiology of Clostridioides difficile reflects a well-established and intricate community transmission network. With rising numbers of reported community-acquired infections, recent studies tried to identify the role played by non-human reservoirs in the pathogen's transmission chain. This study aimed at describing the C. difficile strains circulating in canine and feline populations, and to evaluate their genetic overlap with human strains to assess the possibility of interspecies transmission.

Methods

Fecal samples from dogs (n = 335) and cats (n = 140) were collected from two populations (group A and group B) in Portugal. C. difficile isolates were characterized for toxigenic profile and PCR-ribotyping. The presence of genetic determinants of antimicrobial resistance was assessed in all phenotypically resistant isolates. To evaluate the genetic overlap between companion animals and human isolates from Portugal, RT106 (n = 42) and RT014/020 (n = 41) strains from both sources were subjected to whole genome sequencing and integrated with previously sequenced RT106 (n = 43) and RT014/020 (n = 142) genomes from different countries. The genetic overlap was assessed based on core-single nucleotide polymorphism (SNP) using a threshold of 2 SNP.

Results

The overall positivity rate for C. difficile was 26% (76/292) in group A and 18.6% (34/183) in group B. Toxigenic strains accounted for 50% (38/76) and 52.9% (18/34) of animal carriage rates, respectively. The most prevalent ribotypes (RT) were the toxigenic RT106 and RT014/020, and the non-toxigenic RT010 and RT009. Antimicrobial resistance was found for clindamycin (27.9%), metronidazole (17.1%) and moxifloxacin (12.4%), associated with the presence of the ermB gene, the pCD-METRO plasmid and point mutations in the gyrA gene, respectively. Both RT106 and RT014/020 genetic analysis revealed several clusters integrating isolates from animal and human sources, supporting the possibility of clonal interspecies transmission or a shared environmental contamination source.

Discussion

This study shows that companion animals may constitute a source of infection of toxigenic and antimicrobial resistant human associated C. difficile isolates. Additionally, it contributes with important data on the genetic proximity between C. difficile isolates from both sources, adding new information to guide future work on the role of animal reservoirs in the establishment of community associated transmission networks and alerting for potential public health risk.

Protective Effects of Lactobacillus plantarum Lac16 on Clostridium perfringens Infection-Associated Injury in IPEC-J2 Cells

Clostridium perfringens (C. perfringens) causes intestinal injury through overgrowth and the secretion of multiple toxins, leading to diarrhea and necrotic enteritis in animals, including pigs, chickens, and sheep. This study aimed to investigate the protective effects of Lactobacillus plantarum (L. plantarum) Lac16 on C. perfringens infection-associated injury in intestinal porcine epithelial cell line (IPEC-J2). The results showed that L. plantarum Lac16 significantly inhibited the growth of C. perfringens, which was accompanied by a decrease in pH levels. In addition, L. plantarum Lac16 significantly elevated the mRNA expression levels of host defense peptides (HDPs) in IPEC-J2 cells, decreased the adhesion of C. perfringens to IPEC-J2 cells, and attenuated C. perfringens-induced cellular cytotoxicity and intestinal barrier damage. Furthermore, L. plantarum Lac16 significantly suppressed C. perfringens-induced gene expressions of proinflammatory cytokines and pattern recognition receptors (PRRs) in IPEC-J2 cells. Moreover, L. plantarum Lac16 preincubation effectively inhibited the phosphorylation of p65 caused by C. perfringens infection. Collectively, probiotic L. plantarum Lac16 exerts protective effects against C. perfringens infection-associated injury in IPEC-J2 cells.

Clostridioides difficile infection: an emerging zoonosis?

INTRODUCTION

Clostridioides difficile (C. difficile) infection (CDI) is the most common cause of antibiotic-associated diarrhea and one of the common infections in healthcare facilities. In recent decades, there has been an emerging threat of community-acquired CDI (CA-CDI). Environmental transmission of C. difficile in the community setting has become a major concern, and animals are an important reservoir for C. difficile causing human diseases.

AREAS COVERED

In this article, the molecular epidemiology of C. difficile in animals and recent evidences of zoonotic transfer to humans are reviewed based on an electronic search in the databases of PubMed and Google Scholar.

EXPERT OPINION

C. difficile can be found in stool from diarrheal dogs and cats; therefore, household pets could be a potential source. C. difficile will threaten human health because hypervirulent C. difficile ribotype 078 strains have been found in retail chickens, pig farms, and slaughterhouses. Risk factors for fecal C. difficile carriage in animals include young age, dietary changes, and antibiotic abuse in domestic animals. With the advent of whole genome sequencing techniques, there will be more solid evidence indicating zoonotic transfer of C. difficile from animals to humans.

Changes in the fecal microbiota in dogs with acute hemorrhagic diarrhea during an outbreak in Norway

Background

A severe form of acute hemorrhagic diarrhea syndrome (AHDS) occurred in dogs in the Oslo region of Norway during autumn 2019.

Objectives

To characterize the fecal microbiota of dogs with AHDS during the outbreak and compare it to that of healthy dogs from the same period and before the outbreak.

Animals

Dogs with AHDS (n = 50), dogs with nonhemorrhagic diarrhea (n = 3), and healthy dogs (n = 11) were sampled during the outbreak. In addition, 78 healthy dogs from the same region were sampled before the outbreak between 2017 and 2018.

Methods

Retrospective case‐control study. The fecal microbiotas were characterized using 16S rRNA gene amplicon sequencing.

Results

Dogs with AHDS had significantly different microbiota composition (R² = .07, P < .001) and decreased intestinal diversity relative to healthy dogs from the outbreak period (median, 2.7; range, 0.9‐3.5 vs median, 3.2; range, 2.6‐4.0; P < .001). The microbiota in dogs with AHDS was characterized by a decrease of Firmicutes and an outgrowth of Proteobacteria, with increased numbers of Clostridium perfringens and Providencia spp. Among the Providencia spp., 1 showed 100% sequence identity with a Providencia alcalifaciens strain that was cultivated and isolated from the same outbreak. No Providencia spp. was found in healthy dogs sampled before the outbreak.

Conclusions and Clinical Importance

Dogs with AHDS had marked changes in fecal microbiota including increased numbers of Providencia spp. and C. perfringens, which may have contributed to the severity of this illness.

Molecular Detection of Toxigenic Clostridioides difficile among Diarrheic Dogs and Cats: A Mounting Public Health Concern

Nowadays, pet animals are known to be asymptomatic carriers of Clostridioidesdifficile. This study was conducted to investigate the burden of toxigenic C. difficile among diarrheic dogs and cats using direct PCR on fecal samples to reveal better insights about the epidemiology of such toxigenic strains referring to its public health significance. For this purpose, fecal samples were obtained from 58 dogs and 42 cats experiencing diarrhea. Following DNA extraction, the extracted DNA was examined for the occurrence of C. difficile as well as toxigenic strains through the detection of C. difficile 16S rRNA and toxin encoding genes (tcdA, tcdB, cdtA and cdtB) using PCR. Moreover, partial DNA sequencing of toxigenic strains retrieved from dog and cat was carried out. Of 100 examined diarrheic animals, 90 (90%) were C. difficile positive, including 93.1% and 85.7% of dogs and cats, respectively. In addition, toxigenic strains were detected in 13 animals, giving an overall prevalence 13% with the following prevalence rates among dogs and cats 12.1% and 14.3%, respectively. Furthermore, the phylogenetic analysis of the obtained sequence revealed high genetic relatedness of tcdA sequence obtained from a cat to strains of human diarrheic cases to point out the public health threat of such sequence. In conclusion, the direct detection of toxigenic C. difficile using PCR among dogs and cats highlights the potential role of household pets as a source for such strains to human contacts.

The duration of antibiotic treatment is associated with carriage of toxigenic and non-toxigenic strains of Clostridioides difficile in dogs

Clostridioides difficile is a leading cause of human antibiotic-associated diarrhoeal disease globally. Zoonotic reservoirs of infection are increasingly suspected to play a role in the emergence of this disease in the community and dogs are considered as one potential source. Here we use a canine case-control study at a referral veterinary hospital in Scotland to assess: i) the risk factors associated with carriage of C. difficile by dogs, ii) whether carriage of C. difficile is associated with clinical disease in dogs and iii) the similarity of strains isolated from dogs with local human clinical surveillance. The overall prevalence of C. difficile carriage in dogs was 18.7% (95% CI 14.8–23.2%, n = 61/327) of which 34% (n = 21/61) were toxigenic strains. We found risk factors related to prior antibiotic treatment were significantly associated with C. difficile carriage by dogs. However, the presence of toxigenic strains of C. difficile in a canine faecal sample was not associated with diarrhoeal disease in dogs. Active toxin was infrequently detected in canine faecal samples carrying toxigenic strains (2/11 samples). Both dogs in which active toxin was detected had no clinical evidence of gastrointestinal disease. Among the ten toxigenic ribotypes of C. difficile detected in dogs in this study, six of these (012, 014, 020, 026, 078, 106) were ribotypes commonly associated with human clinical disease in Scotland, while nontoxigenic isolates largely belonged to 010 and 039 ribotypes. Whilst C. difficile does not appear commonly associated with diarrhoeal disease in dogs, antibiotic treatment increases carriage of this bacteria including toxigenic strains commonly found in human clinical disease.

Fermented Rapeseed Meal as a Component of the Mink Diet (Neovison vison) Modulating the Gastrointestinal Tract Microbiota

Fermented rapeseed meal (FRSM) was used in the diet of American mink (Neovison vison). An advantage of this product is its prebiotic and functional properties, which can modify the bacterial microbiota of the GIT. A control group and three experimental groups were formed, with 60 animals in each group. The control group received a basal diet and the experimental groups received a diet with a 2%, 4% or 6% of FRSM as a replacement of extruded wheat. Bacillus subtilis strain 87Y was used to ferment the rapeseed meal (RSM). The study was conducted on mink from the age of 16-17 weeks until slaughter. Changes in the microbiota were analysed in samples of the animals' faeces and intestinal contents. The analyses included determination of the total number of bacteria and fungi, the number of coliforms and Escherichia coli, the total number of anaerobic Clostridium perfringens, and the presence of Salmonella spp. In animals receiving 4% and 6% FRSM (groups II and III), the content of microscopic fungi and the number of C. perfringens bacteria was significantly (p ≤ 0.05) lower than in the animals from the control group (group 0). A decrease in E. coli was observed in all experimental groups (I, II and III), although these differences were not statistically significant. The inclusion of FRSM in the feed ration did not affect the number of lactic acid intestinal bacteria. Analysis of the results obtained from the stool samples showed that the inclusion of FRSM in the ration did not significantly affect the number of microorganisms in each group. However, as in the case of the intestinal contents, in these samples there was a decrease in the total number of C. perfringens in the experimental groups (I, II and III), with a simultaneous increase in the number of mesophilic bacteria in relation to the control. There was no detection of Salmonella bacteria in any of the analysed material.

Dogs are carriers of Clostridioides difficile lineages associated with human community-acquired infections

There is an increasing concern about the role of animals as reservoirs of Clostridioides difficile. In this study, we investigated prevalence, antimicrobial resistance and zoonotic potential of C. difficile in dogs. Two-hundred and twenty-five dog faecal deposits were collected from trashcans in nine public gardens. C. difficile was isolated using selective plating and enrichment culture, identified by MALDI-TOF, tested for susceptibility to seven antibiotics by E-test, and sequenced on an Illumina NextSeq platform. Genome sequences were analysed to determine multilocus sequence types and resistance and toxin gene profiles. Zoonotic potential was assessed by measuring genetic variations of core genome (cg)MLST types between canine isolates and 216 temporally and spatially related human clinical isolates from a national database. C. difficile was isolated from 11 samples (4.9%). Seven isolates were toxigenic (tcdA+, tcdB+, cdtA/B-) and belonged to the sequence types ST2, ST6, ST10 and ST42. The four non-toxigenic isolates were assigned to ST15, ST26 and one novel ST. ST2, corresponding to PCR ribotype RT014/020, was the dominating lineage (n = 4) and, together with ST26 and ST42 isolates, showed close resemblance to human isolates, i.e. 2-5 allelic differences among the 1999 genes analysed by cgMLST. Three non-toxigenic isolates displayed resistance to clindamycin, erythromycin and tetracycline mediated by erm(B) and tet(M). Resistance to metronidazole, moxifloxacine, rifampicin or vancomycin was not detected. In conclusion, a small proportion of faecal deposits contained toxigenic C. difficile such as ST2 (RT014/020), which is a major cause of community-acquired infections. Our finding suggests that pathogenic strains can be exchanged between dogs and humans.

Supplementation of Yeast Cell Wall Fraction Tends to Improve Intestinal Health in Adult Dogs Undergoing an Abrupt Diet Transition

When owners decide to change their pet's food, a rapid transition may cause gastrointestinal distress. Yeast products may help with digestive upset during diet transition due to the bioactive compounds they possess, which may lead to improved intestinal morphology and integrity, modified gut microbiota, and modulated immune responses. The objective of this study was to determine the effects of a yeast cell wall fraction supplement on measures of gut integrity and fecal characteristics of adult dogs undergoing an abrupt diet transition. Twelve adult female beagles (mean age: 5.16 ± 0.87 years; mean body weight: 13.37 ± 0.68 kg) were used in a replicated 4 × 4 Latin square design with four 28-day experimental periods. During days 1-14, dogs were fed a dry kibble diet and supplemented with a placebo (cellulose; 125 mg/d) or yeast product (365 mg/d; equivalent to 0.2% of diet). During days 15-28, dogs remained on their placebo or yeast treatments but were rapidly transitioned to a canned diet or high-fiber diet. Fresh fecal samples were collected on days 13, 16, 20, 24, and 27 for measurement of pH, dry matter, calprotectin, immunoglobulin A (IgA), Escherichia coli, and Clostridium perfringens. Blood samples were collected on days 14, 17, and 28 to measure serum lipopolysaccharide-binding protein concentrations. All data were analyzed using the Mixed Models procedure of SAS 9.4. Fecal pH, dry matter, calprotectin, IgA, and E. coli were not affected (P > 0.05) by treatment before diet transition. Dogs supplemented with yeast cell wall fraction tended to have higher (P = 0.06) fecal C. perfringens counts than the controls. After diet transition, most parameters were not altered (P > 0.05) by treatment except that yeast-supplemented dogs tended to have higher (P = 0.06) fecal IgA than controls. Our results suggest that the yeast product may modestly improve intestinal health after an abrupt diet transition in adult dogs by enhancing intestinal immunity.

Clostridioides difficile carriage in animals and the associated changes in the host fecal microbiota

The relationship between the gut microbiota and Clostridioides difficile, and its role in the severity of C. difficile infection in humans is an area of active research. Intestinal carriage of toxigenic and non-toxigenic C. difficile strains, with and without clinical signs, is reported in animals, however few studies have looked at the risk factors associated with C. difficile carriage and the role of the host gut microbiota. Here, we isolated and characterized C. difficile strains from different animal species (predominantly canines (dogs), felines (cats), and equines (horses)) that were brought in for tertiary care at North Carolina State University Veterinary Hospital. C. difficile strains were characterized by toxin gene profiling, fluorescent PCR ribotyping, and antimicrobial susceptibility testing. 16S rRNA gene sequencing was done on animal feces to investigate the relationship between the presence of C. difficile and the gut microbiota in different hosts. Here, we show that C. difficile was recovered from 20.9% of samples (42/201), which included 33 canines, 2 felines, and 7 equines. Over 69% (29/42) of the isolates were toxigenic and belonged to 14 different ribotypes including ones known to cause CDI in humans. The presence of C. difficile results in a shift in the fecal microbial community structure in both canines and equines. Commensal Clostridium hiranonis was negatively associated with C. difficile in canines. Further experimentation showed a clear antagonistic relationship between the two strains in vitro, suggesting that commensal Clostridia might play a role in colonization resistance against C. difficile in different hosts.

Acute Hemorrhagic Diarrhea Syndrome in Dogs

Acute hemorrhagic diarrhea syndrome is defined as sudden onset of severe bloody diarrhea frequently associated with vomiting, which results in severe, sometimes life-threatening dehydration. Although there is strong evidence that clostridial overgrowth and toxin release is responsible for the pathogenesis of the disease, the diagnosis is still based on exclusion of other causes for acute hemorrhagic diarrhea. With early and appropriate treatment, mainly based on fluid therapy, the prognosis is good and complications such as sepsis or severe hypoalbuminemia rarely occur.

Prevalence, Colonization, Epidemiology, and Public Health Significance of Clostridioides difficile in Companion Animals

Clostridioides difficile, previously Clostrdium difficile, is a major cause of antibiotic-associated enteric disease in humans in hospital settings. Increased incidence of C. difficile infection (CDI) in community settings raises concerns over an alternative source of CDI for humans. The detection of genetically similar and toxigenic C. difficile isolates in companion animals, including asymptomatic pets, suggests the potential role of household pets as a source of community-associated CDI. The close association between companion animals and humans, in addition to the use of similar antibiotics in both species, could provide a selective advantage for the emergence of new C. difficile strains and thus increase the incidental transmission of CDI to humans. Therefore, screening household pets for C. difficile is becoming increasingly important from a public health standpoint and may become a part of routine testing in the future, for the benefit of susceptible or infected individuals within a household. In this review, we analyze available information on prevalence, pathophysiology, epidemiology, and molecular genetics of C. difficile infection, focusing on companion animals and evaluate the risk of pet-borne transmission of CDI as an emerging public health concern. Molecular epidemiological characterization of companion animal C. difficile strains could provide further insights into the interspecies transmission of CDI. The mosaic nature of C. difficile genomes and their susceptibility to horizontal gene transfer may facilitate the inter-mixing of genetic material, which could increase the possibility of the emergence of new community-associated CDI strains. However, detailed genome-wide characterization and comparative genome analysis are warranted to confirm this hypothesis.

Effect of amoxicillin-clavulanic acid on clinical scores, intestinal microbiome, and amoxicillin-resistant Escherichia coli in dogs with uncomplicated acute diarrhea

Background

Despite limited evidence of efficacy, antibiotic treatment is still frequently prescribed in dogs with uncomplicated acute diarrhea (AD).

Objective

To assess whether amoxicillin‐clavulanic acid has a clinical benefit, an effect on the fecal microbiome, and the proportion of amoxicillin‐resistant Escherichia coli in dogs with AD.

Animals

Sixteen dogs with AD of <3 days duration.

Methods

Prospective, placebo‐controlled, double‐blinded study. Clinical scores were compared between client‐owned dogs randomly assigned to an antibiotic (AG) or a placebo (PG) group. The intestinal microbiome was analyzed using quantitative PCR assays. Amoxicillin‐resistant fecal E. coli were assessed semiquantitatively with microbiological methods.

Results

There was no difference in clinical recovery between treated dogs or controls (CADS index day 10: AG group median: 2 (range: 1‐3; CI [1.4; 2.6]); PG group median: 1.6 (range: 1‐3; CI [1.1; 2.4]); P > .99). All dogs gained normal clinical scores (CADS index ≤3) after 1 to 6 days (median 2 days) after presentation. There was no significant difference in the fecal dysbiosis index (during treatment: AG mean −2.6 (SD 3.0; CI [−5.1; 0.0]); PG mean −0.8 (SD 4.0; CI [−4.2; 2.5]; P > .99) or its bacterial taxa. The proportion of resistant fecal E. coli increased (to median: 100%; range: 35%‐100%) during treatment with amoxicillin‐clavulanic acid and was still increased (median: 10%; range 2%‐67%) 3 weeks after treatment, both of which were significantly higher proportions than in the placebo group for both time points (during treatment AG median 100% versus PG median 0.2% (P < .001); after treatment AG median 10% versus PG median 0.0% (P = .002)).

Conclusions and Clinical Importance

Our study suggests that treatment with amoxicillin‐clavulanic acid confers no clinical benefit to dogs with AD, but predisposes the development of amoxicillin‐resistant E. coli, which persist for as long as 3 weeks after treatment. These findings support international guideline recommendations that dogs with diarrhea should not be treated with antimicrobials unless there are signs of sepsis.

Effects of probiotic Lactobacillus acidophilus D2/CSL (CECT 4529) on the nutritional and health status of boxer dogs

Background

The aim of the present study was to investigate the effects of Lactobacillus acidophilus D2/CSL (CECT 4529) probiotic strain on nutritional status and faecal and microbiological parameters in a group of purebred boxers.

Methods

Forty healthy adult boxer dogs were randomly assigned to a treated (LACTO) group receiving a commercial diet supplemented with L acidophilus D2/CSL (CECT 4529) to a final concentration of 5.0 x 10⁹ colony-forming unit/kg of food, and a control (CTR) group receiving the same diet but without the probiotic (placebo). Nutritional status (body weight, skinfold thickness, body condition score) and faecal quality parameters were analysed.

Results

No differences in body weight and skin thickness were found during the whole experimental period. Dogs in the LACTO group showed a significantly higher body condition score than those in the CTR group (4.86±0.55 v 4.65±0.65), and no significant differences were recorded in body weight and skinfold thickness. The LACTO group showed a significantly lower faecal moisture (in per cent) compared with the CTR group (0.67±0.007 v 0.69±0.007). Faecal hardness (in kg) was higher in the LACTO group than in the CTR group (0.86±0.047 v 0.70±0.051), and faecal score also improved in the LACTO group (3.78±0.95 v 4.25±0.91). A significant difference in total Escherichia coli counts as well as in lactobacilli counts between the CTR and LACTO groups was only detected at 28 days.

Conclusion

Supplementation of L acidophilus D2/CSL (CECT 4529) significantly improved the nutritional status and faecal parameters of dogs.

Clostridium (Clostridioides) difficile in animals

Clostridium (Clostridioides) difficile is a gram-positive, spore-forming bacterium that is an important cause of disease in people, a variably important cause of disease in some animal species, and an apparently harmless commensal in others. Regardless of whether it is a known pathogen in a particular species, it can also be found in healthy individuals, sometimes at high prevalences and typically with higher rates of carriage in young individuals. As it is investigated in more animal species, it is apparent that this bacterium is widely disseminated in a diverse range of domestic and wild animal species. Although it can be found in most species in which investigations have been performed, there are pronounced intra- and inter-species differences in prevalence and clinical relevance. A wide range of strains can be identified, some that appear to be animal associated and others that are found in humans and animals. A large percentage of strains that cause disease in people can at least sporadically be found in animals. It is a potentially important zoonotic pathogen, but there is limited direct evidence of animal-human transmission. Although C. difficile has been studied extensively over the past few decades, it remains an enigmatic organism in many ways.

Effects of Lactobacillus acidophilus D2/CSL (CECT 4529) supplementation on healthy cat performance

Background

The present study aimed to evaluate the effects of the probiotic strain Lactobacillus acidophilus D2/CSL (CECT 4529) on nutritional condition and faecal quality in cats.

Methods

Ten healthy adult cats from the same cattery were included (aged >9 months; male:female sex ratio=3:7). The animals were randomly assigned to a control group (CTR; n=5; male:female=1:4; room 1: 16 m²) and to a treated group (LACTO; n=5; male:female=2:3; room 2: 16 m²) receiving the same commercial dry diet. The LACTO group diet was supplemented with the probiotic (5 x 10⁹ cfu/kg feed at least). A five-week experimental period was applied, and nutritional status was monitored by bodyweight (BW) and body condition score (BCS). Faecal quality was evaluated using faecal score (FS) and faecal moisture (FM) parameters. Plate counts of some faecal bacteria species were carried out. The data obtained were analysed using MIXED, GLM and NPAR1WAY procedures (SAS V.9.4; P≤0.05).

Results

The two groups did not show differences in BW and BCS data. A clear effect of the probiotic supplementation on FM was recorded (LACTO 44 per cent v CTR group 46 per cent; P=0.04). FS in the LACTO group (3.35) was close to ideal values (2-3) in comparison with the CTR group (3.75). Positive effects of L acidophilus D2/CSL have been recorded in terms of increase in faecal lactobacilli counts and reduction in faecal coli counts.

Conclusions

This study's preliminary results describe how inclusion of L acidophilus D2/CSL (CECT 4529) probiotic strain in cats' diets could effectively improve faecal quality parameters and consequently gut health in adult healthy cats.

Evaluation of microbial contamination and effects of storage in raw meat-based dog foods purchased online

Feeding raw-meat-based diets to companion animals has become a widespread practice, and many owners are now accustomed to buying frozen ingredients online. The goals of this study were to assess the microbiological quality of raw-meat dog foods obtained from specialized websites and to evaluate the effects of storage at different temperatures for a few days. Twenty-nine raw dog food products were processed for quantitative bacteriology (i.e. total viable count, TVC; Escherichia coli; faecal coliforms, FC) and sulphite-reducing clostridia, and analysed for the presence of Salmonella spp., Listeria monocytogenes, Yersinia enterocolitica and Clostridium difficile. Every sample was examined right after the delivery (T0), after 24 to 48 hr and after 72 hr, both at 2°C and 7°C. At T0, the mean score for the TVC was 5.9 × 10⁶  cfu/g (SD = 4.8 × 10⁷  cfu/g), while those for E. coli and FC were 1.1 × 10⁴  cfu/g (SD = 2.5 × 10⁵  cfu/g) and 3.3 × 10³  cfu/g (SD = 6.5 × 10⁴  cfu/g) respectively. The samples stored at 2°C had a significant increase of all parameters (TVC: p < .01; E. coli: p = .03; FC: p = .04) through time. Noteworthy differences between the analyses performed at 2°C and 7°C were found for TVC (p < .01), being the samples considerably more contaminated at higher temperatures. No sample tested positive for Salmonella spp., while L. monocytogenes was isolated from 19 products, Y. enterocolitica from three products and Clostridium perfringens and C. difficile from four and six products respectively. The microbiological quality of raw-meat dog foods sold online appears to be poor, carrying considerable amounts of potentially zoonotic bacteria and reaching greater levels of bacterial contaminations if not kept at proper refrigeration temperatures and fed soon after defrosting.

Metronidazole treatment of acute diarrhea in dogs: A randomized double blinded placebo-controlled clinical trial

BACKGROUND

Metronidazole is commonly administered to dogs with acute diarrhea, but there is limited evidence to support this practice.

OBJECTIVE

To investigate the effects of metronidazole administration on dogs with acute nonspecific diarrhea.

ANIMALS

Thirty-one dogs, including 14 test population dogs and 17 controls.

METHODS

Randomized controlled clinical trial. Dogs with acute diarrhea in which causation was not determined by routine fecal diagnostic testing were randomly assigned to metronidazole treatment (10-15 mg/kg PO q12h for 7 days) or placebo. Fecal cultures and characterization of Clostridium perfringens isolates also were performed. Owners maintained medication and fecal scoring logs, and fecal diagnostic tests were repeated on day 7.

RESULTS

The mean ± SD time to resolution of diarrhea for test population dogs (2.1 ± 1.6 days) was less than that for controls (3.6 ± 2.1 days, P = .04). Potential relationships of C. perfringens with acute diarrhea pathogenesis were not investigated, but only 3 of 13 (23.1%) test population dogs had persistent C. perfringens carriage at day 7, which was less than the 11 of 14 (78.6%) controls with persistent growth (P = .007).

CONCLUSIONS AND CLINICAL IMPORTANCE

Our results suggest that metronidazole treatment can shorten duration of diarrhea and decrease fecal culture detection of C. perfringens in some dogs with acute nonspecific diarrhea. Additional studies are needed to assess the benefits and risks of routine use of metronidazole for this purpose because most dogs achieve resolution of diarrhea within several days regardless of treatment.

Characterization of Clostridioides difficile ribotypes in domestic dogs in Rio de Janeiro, Brazil

Clostridioides difficile is the major etiologic agent of nosocomial bacterial diarrhoea and pseudomembranous colitis. The pathogenesis of C. difficile infection (CDI)involves two cytotoxic enzymes (TcdA, TcdB) that cause colonic epithelial damage, fluid accumulation and enteritis. CDI has been demonstrated in a variety of animal species and some reports have recently raised the importance of wild animals as a reservoir of this pathogen and possible transmission to humans and domestic animals. The aim of this study was to characterize C. difficile isolates obtained from pet dogs in Rio de Janeiro, Brazil. A total of 50 faecal samples were obtained from healthy and diarrheic dogs. Five of fifty samples (10%) grew C. difficile. Of those, three belonged to the PCR ribotype 106 (ST 42) and were toxigenic (A⁺B⁺). The other two strains belonged to the PCR ribotype 010 (ST 15) and were not toxin producers (A^-B^-). None of the isolates tested positive for the binary toxin genes. Considering the antimicrobial resistance patterns of all isolates using EUCAST breakpoints, all strains were sensitive to metronidazole and vancomycin. However, two strains (ribotype 106 and ribotype 010), were resistant to clindamycin (≤256 μg/mL). All strains were strong biofilm producers. Our study provides evidence that dogs can act as reservoirs for C. difficile epidemic ribotypes.

Clostridium difficile shedding by healthy dogs in Nigeria and Malawi

The objectives of this study were to determine the prevalence and characteristics of Clostridium difficile shedding in owned dogs in Nigeria and Malawi. Clostridium difficile was isolated from 31/120 (26%) dogs in Nigeria and 11/92 (12%) dogs in Malawi (p = 0.012). Overall, 22/42 (52%) isolates were toxigenic; 17/31 (55%) from Nigeria and 5/11 (45%) from Malawi. All toxigenic isolates possessing tcdA and tcdB, and only one also possessed cdtA/B. Sixteen different ribotypes were found, ten (63%) of which were non-toxigenic. Most isolates corresponded to ribotypes that have been previously identified in humans or livestock. The role of dogs in transmission of C. difficile and the clinical implications of C. difficile shedding in dogs remain unclear. These data indicate that dogs could act as a source of C. difficile for exposure of other species, including humans; however, the true risk is unknown. Further study of the ecology of C. difficile and the role of dogs in disease of humans and other domestic animals is indicated.

A Randomized Double Blinded Placebo-Controlled Clinical Trial of a Probiotic or Metronidazole for Acute Canine Diarrhea

Acute diarrhea is a common, often self-limiting, cause of presentation for veterinary care, yet there is a paucity of data on frequently-prescribed treatments. The purpose of this randomized, double blinded placebo-controlled clinical trial was to compare two anecdotally-recommended treatments: a probiotic combination and metronidazole. Sixty dogs without concurrent comorbidities were randomized into three treatment groups. The time to resolution of diarrheal signs was evaluated using owner surveys and fecal scoring charts. Dogs presenting with acute diarrhea achieved acceptable fecal consistency after 3.5 ± 2.2 days when receiving probiotic, 4.6 ± 2.4 days with oral metronidazole, and 4.8 ± 2.9 days with placebo; statistically significant differences were not identified between treatment groups (p = 0.17). These findings failed to provide evidence for the common use of metronidazole in this cohort of dogs with acute canine diarrhea, and a larger study population would be required to identify a statistically significant effect of probiotics.

Clostridioides difficile in bat guano

Bats are associated with the emergence of several mammalian diseases. Their sessional migration, and tendency to form large colonies in close proximity to human habitats enables effective intra- and inter-species transmission of pathogens. Clostridioides difficile is an important enteric pathogen in humans and animals; however, the source of its dissemination in the population is unknown. The purpose of this study was to determine the prevalence of C. difficile in bats, and to characterize C. difficile isolates. Feces (n = 93) was sampled from bats during their migration across Europe. Eighteen samples (19.4%) were positive for C. difficile; ribotypes 078, 056, and a new ribotype CDB3 were identified. Clostridioides difficile ribotypes 078 and 056 are associated with human and animal diseases. The C. difficile prevalence and ribotypes in this study do not necessarily identify bats as a significant source, but more likely as an indicator of C. difficile perpetuation in the environment.

Occurrence of Salmonella, Campylobacter, Clostridium and Enterobacteriaceae in raw meat-based diets for dogs

The practice of feeding raw meat-based diets (RMBD) to dogs has increased in popularity in recent years. However, RMBD are based on offal that has not undergone any type of treatment to reduce the microbial content, so there is a risk of potential pathogenic microorganisms being present. Frozen samples from 60 RMBD packs produced by 10 different manufacturers were analysed for their content of bacteria belonging to the family Enterobacteriaceae, for Clostridium perfringens and for the presence of Salmonella and Campylobacter. Enterobacteriaceae were detected in all 60 samples and in 31 samples exceeded a level of 5000 bacteria/g, which is the threshold for satisfactory microbial hygiene according to EU regulations. In two samples, the amount of C. perfringens exceeded 5000 bacteria/g, which is the maximum level of anaerobic bacteria permitted by Swedish national guidelines. Salmonella species were found in four (7 per cent) and Campylobacter species in three (5 per cent) samples. These results show that it is critical to maintain good hygiene when storing, handling and feeding RMBD, in order to limit the potential health risks to animals and humans, especially young and immunocompromised individuals.

Oral faecal microbiota transplantation for the treatment of Clostridium difficile-associated diarrhoea in a dog: a case report

Background

Successful clinical outcomes of faecal microbiota transplantation (FMT) for recurrent Clostridium difficile infection have been reported in humans and a marmoset. However, it has been unclear whether oral FMT was effective for the treatment of C. difficile-associated diarrhoea in dogs.

Case presentation

An 8-month-old, intact male French bulldog was presented with a 4-month history of intermittent large bowel diarrhoea. Physical and clinical examinations did not identify any specific causes for diarrhoea. Real-time PCR analysis and immunochromatography detected C. difficile antigen and toxin A&B genes and proteins in a faecal sample. Based on these findings, diarrhoea in the dog was considered to be induced by C. difficile-associated colitis. The dog was treated with oral FMT, in which a faecal solution obtained from a healthy beagle was orally administered to the subject. Stool consistency and frequency and faecal blood and mucus became normal 2–3 days after oral FMT, and real-time PCR analysis and immunochromatography was negative for C. difficile antigen and toxin A&B genes and proteins. No adverse events were observed.

Conclusion

The present case report demonstrated that oral FMT was an effective treatment for C. difficile-associated diarrhoea in a dog. The findings in this report provide a rationale to evaluate clinical efficacy of oral FMT for other gastrointestinal diseases in dogs.

Quantification of Clostridioides (Clostridium) difficile in feces of calves of different age and determination of predominant Clostridioides difficile ribotype 033 relatedness and transmission between family dairy farms using multilocus variable-number tandem-repeat analysis

BACKGROUND

Community acquired Clostridioides (Clostridium) difficile infection (CA-CDI) is a significant health problem in human and veterinary medicine. Animals are often considered as potential reservoirs for CA-CDI. In Europe, family farming is the most predominant farming operation, with a complex interaction between animals and the community. Therefore, it is pertinent to evaluate transmission patterns of C. difficile on such prominent European farming model. Fecal samples from calves (n = 2442) were collected biweekly over a period of one year on 20 mid-size family dairy farms. Environmental samples (n = 475) were collected in a three month interval. Clostridioides difficile was detected using qPCR in 243 fecal samples (243/2442); positive samples were then quantified. Association between prevalence/load of C. difficile and age of the calves was estimated with logistic regression model. Most common C. difficile isolate from calves (n = 76) and the environment (n = 14) was C. difficile ribotype 033, which was further analyzed using multilocus variable-number tandem-repeat analysis (MLVA) to assess intra- and between-farm relatedness.

RESULTS

Clostridioides difficile was detected in feces of calves less than 24 h old. Results showed a non-linear statistically significant decrease in shedding load of C. difficile with age (P < 0.0001). A nonlinear relationship was also established between the number of calves and the farm C. difficile prevalence, whereas the prevalence of C. difficile ribotype 033 increased linearly with the number of calves. MLVA revealed close intra-farm relatedness among C. difficile ribotypes 033. It also revealed that the between-farms close relatedness of C. difficile ribotypes 033 can be a direct result of farm to farm trade of calves.

CONCLUSIONS

Implementation of better hygiene and management measures on farms may help decrease the risk of spreading CA-CDI between animals and the community. Trading calves older than 3 weeks would decrease the possibility C. difficile dissemination in the community because of lower prevalence and lower load of C. difficile in feces.

Effect of probiotic treatment on the clinical course, intestinal microbiome, and toxigenic Clostridium perfringens in dogs with acute hemorrhagic diarrhea

INTRODUCTION

The impact of probiotics on dogs with acute hemorrhagic diarrhea syndrome (AHDS) has not been evaluated so far. The study aim was to assess the effect of probiotic treatment on the clinical course, intestinal microbiome, and toxigenic Clostridium perfringens in dogs with AHDS in a prospective, placebo-controlled, blinded trial.

METHODS

Twenty-five dogs with AHDS with no signs of sepsis were randomly divided into a probiotic (PRO; Visbiome, ExeGi Pharma) and placebo group (PLAC). Treatment was administered for 21 days without antibiotics. Clinical signs were evaluated daily from day 0 to day 8. Key bacterial taxa, C. perfringens encoding NetF toxin and enterotoxin were assessed on days 0, 7, 21.

RESULTS

Both groups showed a rapid clinical improvement. In PRO a significant clinical recovery was observed on day 3 (p = 0.008), while in PLAC it was observed on day 4 (p = 0.002) compared to day 0. Abundance of Blautia (p<0.001) and Faecalibacterium (p = 0.035) was significantly higher in PRO on day 7 compared to day 0, while in PLAC the abundance of Faecalibacterium was not significantly higher on any study day and Blautia (p = 0.016) was only significantly higher on day 21 compared to day 0. Abundance of C. perfringens was significantly lower on day 7 (p = 0.011) compared to day 0 in PRO but not in PLAC. Enterotoxin genes were significantly lower in PRO on day 21 (p = 0.028) compared to PLAC. Fecal samples of 57% of all dogs were positive for netF toxin genes on day 0 and the abundance was significantly lower on day 7 compared to day 0 in PRO (p = 0.016) and PLAC (p = 0.031).

CONCLUSION

The probiotic treatment was associated with an accelerated normalization of the intestinal microbiome. Dogs with aseptic AHDS showed a rapid decrease of netF toxin genes and fast clinical recovery in both groups under symptomatic treatment without antibiotics.

Understanding Clostridium difficile Colonization

Clostridium difficile is the main causative agent of antibiotic-associated and health care-associated infective diarrhea. Recently, there has been growing interest in alternative sources of C. difficile other than patients with Clostridium difficile infection (CDI) and the hospital environment. Notably, the role of C. difficile-colonized patients as a possible source of transmission has received attention. In this review, we present a comprehensive overview of the current understanding of C. difficile colonization. Findings from gut microbiota studies yield more insights into determinants that are important for acquiring or resisting colonization and progression to CDI. In discussions on the prevalence of C. difficile colonization among populations and its associated risk factors, colonized patients at hospital admission merit more attention, as findings from the literature have pointed to their role in both health care-associated transmission of C. difficile and a higher risk of progression to CDI once admitted. C. difficile colonization among patients at admission may have clinical implications, although further research is needed to identify if interventions are beneficial for preventing transmission or overcoming progression to CDI.

Preliminary studies on isolates of Clostridium difficile from dogs and exotic pets

Background

Clostridium difficile infection (CDI) is recognised as an emerging disease in both humans and some animal species. During the past few years, insights into human CDI epidemiology changed and C. difficile is also considered as an emerging community-acquired pathogen. Certain ribotypes (RT) are possibly associated with zoonotic transmission. The objective of this study was to assess the presence of C. difficile in a population of pets and to characterise the isolates.

Results

Faecal samples from a total of 90 diarrhoeic dogs and 24 from exotic animal species (both diarrhoeic and non-diarrhoeic) were analysed. Clostridium difficile was isolated from 6 (6.7%) dogs and one reptile sample (4.2%). Four (66.7%) of the six dog strains were capable of producing toxins. Four known different RTs were detected in dogs (010, 014, 123 and 358) and a new one was found in a faecal sample of an exotic animal. This new RT isolate was negative for all toxin genes tested and belonged to sequence type 347 which has been proposed as a Clade-III member. Importantly, two dog strains showed a stable resistance to metronidazole (initial MIC values: 128 and 48 μg/ml).

Conclusions

The results obtained in this study suggest the implementation of antimicrobial susceptibility surveillance programs to assess the prevalence of metronidazole resistance in dogs; molecular studies to elucidate C. difficile metronidazole resistance mechanisms are warranted. Based on the similarity between the ribotypes observed in dogs and those described in humans, the zoonotic transmission should be further explored. Furthermore, exotic animals have shown to harbor uncommon C. difficile strains which require further genomic studies.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1402-7) contains supplementary material, which is available to authorized users.

The zoonotic potential of Clostridium difficile from small companion animals and their owners

Background

Clostridium difficile infections (CDI) in humans range from asymptomatic carriage to life-threatening intestinal disease. Findings on C. difficile in various animal species and an overlap in ribotypes (RTs) suggest potential zoonotic transmission. However, the impact of animals for human CDI remains unclear.

Methods

In a large-scale survey we collected 1,447 fecal samples to determine the occurrence of C. difficile in small companion animals (dogs and cats) and their owners and to assess potential epidemiological links within the community. The Germany-wide survey was conducted from July 2012-August 2013. PCR ribotyping, Multilocus VNTR Analysis (MLVA) and PCR detection of toxin genes were used to characterize isolated C. difficile strains. A database was defined and logistic regression used to identify putative factors associated with fecal shedding of C. difficile.

Results

In total, 1,418 samples met the inclusion criteria. The isolation rates for small companion animals and their owners within the community were similarly low with 3.0% (25/840) and 2.9% (17/578), respectively. PCR ribotyping revealed eight and twelve different RTs in animals and humans, respectively, whereas three RTs were isolated in both, humans and animals. RT 014/0, a well-known human hospital-associated lineage, was predominantly detected in animal samples. Moreover, the potentially highly pathogenic RTs 027 and 078 were isolated from dogs. Even though, C. difficile did not occur simultaneously in animals and humans sharing the same household. The results of the epidemiological analysis of factors associated with fecal shedding of C. difficile support the hypothesis of a zoonotic potential.

Conclusions

Molecular characterization and epidemiological analysis revealed that the zoonotic risk for C. difficile associated with dogs and cats within the community is low but cannot be excluded.

Chronic Diarrhea in Dogs - Retrospective Study in 136 Cases

Background

Chronic diarrhea (CD) is common in dogs, and information on frequency and distribution of primary and secondary causes is lacking.

Objectives

To evaluate underlying causes and predictors of outcome in dogs with CD.

Animals

One hundred and thirty‐six client‐owned dogs with CD (≥3 weeks duration).

Methods

Retrospective review of medical records (Small Animal Clinic, Freie Universität Berlin, Germany, 09/2009‐07/2011). Quantification of final diagnoses and comparison of clinical aspects including disease severity and clinicopathological abnormalities among dogs with clinical remission (either complete [gastrointestinal signs absent] or partial [clinical improvement of gastrointestinal signs and reduced episodes with shortened duration]), and those without recovery.

Results

Ninety percent of dogs were diagnosed with a primary enteropathy: inflammatory (71%; of those 66% dietary responsive, 23% idiopathic, 11% antibiotic responsive), infectious (13%), neoplastic (4%), and in one dog each mechanical disease or systemic vasculitis. Secondary causes were diagnosed in 10% of dogs: exocrine pancreatic (6%), endocrine (2%), and in one dog each hepatic, renal, and cardiac disease. In total, 87% of dogs had clinical remission, whereas 13% died or did not respond to treatment: Lack of recovery was frequently recorded for dogs with primary inflammatory (idiopathic) or neoplastic disease and was significantly associated with increased disease severity scores (P = .005), anemia (hematocrit < 40%, P < .001), severe hypoalbuminemia (serum albumin <2.0 g/dL, P = .008), and severe hypocobalaminemia (serum cobalamin concentration <200 pg/mL, P = .006).

Conclusions and clinical importance

Inflammatory enteropathies and particularly those of dietary origin were the most common causes of CD in dogs. Findings support the usefulness of hematocrit, and serum albumin and cobalamin concentration as prognostic markers in dogs with CD.

Role of the gastrointestinal microbiota in small animal health and disease

There is a large and emerging interest in the role of the gastrointestinal microbiota in health and disease. This paper serves to review the current knowledge and recommendations of the gastrointestinal microbiota in health and gastrointestinal disease. Further, this review evaluates the current literature and suggests guidelines for faecal microbial transplantation, a novel therapy for dysbiosis in veterinary medicine.

Clostridium perfringens and C. difficile in parvovirus-positive dogs

The aim of this study was to investigate Clostridium difficile and Clostridium perfringens in 82 diarrheic dogs positive for canine parvovirus type 2 (CPV). Enterotoxigenic C. perfringens type A was isolated from three (3.6%) dogs. One (1.2%) strain was also positive for NetE- and NetF-encoding genes, which are commonly associated with diarrhea in dogs. Toxigenic C. difficile was isolated from one animal (1.2%), which was also positive for A/B toxins. The present study identified C. difficile and C. perfringens infection in CPV-positive dogs. Further studies are necessary to clarify if clostridial infections may predispose or potentiate CPV-infection in dogs or vice versa.

•

The co-infection of canine parvovirus (CPV) and toxigenic clostridia is still poorly understood.

•

82 CPV-positive dogs were tested for C. perfringens netF+ and C. difficile infection (CDI).

•

C. perfringens type A positive for NetF-encoding gene (netF) was recovered from an adult dog (1.2%).

•

C. difficile was isolated from ten 12.2% (10/82) dogs, but in only one CDI was confirmed.

•

To our knowledge, this is the first study that report C. perfringen netF positive in CPV-positive dogs.

Prevalence and characteristics of Clostridium perfringens and Clostridium difficile in dogs and cats attended in diverse veterinary clinics from the Madrid region

Despite extensive research on the epidemiology of pathogenic clostridia in dogs and cats, most published studies focus on a selected animal population and/or a single veterinary medical centre. We assessed the burden of Clostridium perfringens and C. difficile shedding by small animals in 17 veterinary clinics located within the Madrid region (Spain) and differing in size, number and features of animals attended and other relevant characteristics. In addition, we studied the genetic diversity and antibiotic susceptibility of recovered isolates. Selective culture of all fecal specimens collected during a single week from dogs (n = 105) and cats (n = 37) attended in participating clinics yielded C. perfringens/C. difficile from 31%, 4.8% of the dogs, and 20%, 0% of the cats analyzed, respectively, and three dogs yielded both species. Furthermore, 17 animals (15 dogs and two cats) that yielded a positive culture for either species were recruited for a follow-up survey and C. perfringens was again obtained from nine dogs. Considerable differences in prevalence were observed among participating clinics for both clostridial species. C. perfringens isolates (n = 109) belonged to toxinotypes A (97.2%) and E (three isolates from one dog), whereas C. difficile isolates (n = 18) belonged to the toxigenic ribotypes 106 (33.3%) and 154 (16.7%), a 009-like ribotype (33.3%) and an unknown non-toxigenic ribotype (16.7%). Amplified fragment length polymorphism-based fingerprinting classified C. perfringens and C. difficile isolates into 105 and 15 genotypes, respectively, and tested isolates displayed in vitro resistance to benzylpenicillin (2.8%, 88.8%), clindamycin (0%, 16.7%), erythromycin (0.9%, 16.7%), imipenem (1.8%, 100%), levofloxacin (0.9%, 100%), linezolid (5.5%, 0%), metronidazole (4.6%, 0%) and/or tetracycline (7.3%, 0%). All animals from which multiple isolates were retrieved yielded ≥2 different genotypes and/or antimicrobial susceptibility profiles. Future studies should focus on the seasonal and geographical variations of prevalence and diversity patterns of clostridial species in small animals.

Isolation of Clostridium difficile from dogs with digestive disorders, including stable metronidazole-resistant strains

The prevalence of Clostridium difficile in 107 dogs with diverse digestive disorders attended in a Spanish veterinary teaching hospital was assessed. The microorganism was isolated from 13 dogs (12.1%) of different disease groups. Isolates belonged to PCR ribotypes 078, 106, 154 and 430 (all of them toxigenic) and 110 (non-toxigenic), and were resistant to several antimicrobial drugs. Notably, seven isolates obtained from different dogs displayed stable resistance to metronidazole. The results of this study provide further evidence that dogs can act as a reservoir of C. difficile strains of epidemic ribotypes with resistance to multiple antibiotics.

Prevalence of Enteropathogens in Dogs Attending 3 Regional Dog Parks in Northern California

Background

The prevalence and risk factors for infection with enteropathogens in dogs frequenting dog parks have been poorly documented, and infected dogs can pose a potential zoonotic risk for owners.

Hypothesis/Objectives

To determine the prevalence and risk factors of infection with enteropathogens and zoonotic Giardia strains in dogs attending dog parks in Northern California and to compare results of fecal flotation procedures performed at a commercial and university parasitology laboratory.

Animals

Three‐hundred dogs attending 3 regional dog parks in Northern California.

Methods

Prospective study. Fresh fecal specimens were collected from all dogs, scored for consistency, and owners completed a questionnaire. Specimens were analyzed by fecal centrifugation flotation, DFA, and PCR for detection of 11 enteropathogens. Giardia genotyping was performed for assemblage determination.

Results

Enteropathogens were detected in 114/300 dogs (38%), of which 62 (54%) did not have diarrhea. Frequency of dog park attendance correlated significantly with fecal consistency (P = .0039), but did not correlate with enteropathogen detection. Twenty‐seven dogs (9%) were infected with Giardia, and genotyping revealed nonzoonotic assemblages C and D. The frequency of Giardia detection on fecal flotation was significantly lower at the commercial laboratory versus the university laboratory (P = .013), and PCR for Giardia was negative in 11/27 dogs (41%) that were positive on fecal flotation or DFA.

Conclusions and Clinical Importance

Enteropathogens were commonly detected in dogs frequenting dog parks, and infection with Giardia correlated with fecal consistency. PCR detection of Giardia had limited diagnostic utility, and detection of Giardia cysts by microscopic technique can vary among laboratories.

The Comparative Pathology of Clostridium difficile-associated Disease

Clostridium difficile is a confirmed pathogen in a wide variety of mammals, but the incidence of disease varies greatly in relation to host species, age, environmental density of spores, administration of antibiotics, and possibly, other factors. Lesions vary as well, in severity and distribution within individuals, and in some instances, age groups, of a given species. The cecum and colon are principally affected in most species, but foals and rabbits develop severe jejunal lesions. Explanations for variable susceptibility of species, and age groups within a species, are largely speculative. Differences in colonization rates and toxin-receptor densities have been proposed. Clostridium difficile-associated disease is most commonly diagnosed in Syrian hamsters, horses, and neonatal pigs, but it is reported sporadically in many other species. The essential virulence factors of C. difficile are large exotoxins, toxin A (TcdA) and toxin B (TcdB). Receptor-mediated endocytosis of the toxins is followed by endosomal acidification, a necessary step for conversion of the toxin to its active form in the cytosol. Cell-surface receptors have been characterized for TcdA, but remain to be identified for TcdB. Both TcdA and TcdB disrupt the actin cytoskeleton by disrupting Rho-subtype, intracellular signaling molecules. Disruption of the actin cytoskeleton is catastrophic for cellular function, but inflammation and neurogenic stimuli are also involved in the pathogenesis of the disease.

Evaluation of Five Enzyme Immunoassays Compared with the Cytotoxicity Assay for Diagnosis of Clostridium Difficile-Associated Diarrhea in Dogs

Clostridium difficile-associated-diarrhea (CDAD) is a nosocomial infection in dogs. Diagnosis of this infection is dependent on clinical signs of disease supported by laboratory detection of C. difficile toxins A or B, or both, in fecal specimens via enzyme-linked immunosorbent assay (ELISA). Unfortunately, to the authors' knowledge, commercially available ELISAs have not been validated in dogs to date. We evaluated 5 ELISAs done on 143 canine fecal specimens (100 diarrheic and 43 nondiarrheic dogs) and on 29 C. difficile isolates. The results of each ELISA were compared with the cytotoxin B tissue culture assay (CTA). Clostridium difficile was isolated from 23% of the fecal specimens. Eighteen of the 143 fecal specimens were toxin positive (15 diarrheic and 3 nondiarrheic dogs). On the basis of multiplex polymerase chain reaction (PCR) analysis for toxin-A and -B genes, 72% of the isolates were toxigenic. The carriage rate of toxigenic isolates in diarrheic dogs was higher than that in the nondiarrheic dogs; however, these differences were not statistically significant. A good correlation was found between CTA, PCR, and culture results. The ELISAs done on fecal specimens collected from diarrheic dogs had low sensitivity (7–33%). In contrast, ELISA for toxin A or B, or both, performed on toxigenic isolates had high sensitivity (93%). These results suggest that commercially available human ELISAs are inadequate for the diagnosis of canine C. difficile-associated diarrhea when tested on fecal specimens. In contrast, the Premier ToxinA/B and Techlab ToxinA/B ELISAs may be useful for the diagnosis of canine CDAD when used on toxigenic isolates.

A Prospective, Case Control Study Evaluating the Association between Clostridium Difficile Toxins in the Colon of Neonatal Swine and Gross and Microscopic Lesions

Clostridium difficile infection in swine has most often been described in suckling pigs, where it has been associated with mesocolonic edema and typhlocolitis. This prospective study was designed to assess the correlation between the presence of C. difficile toxins (TCd) in the colon contents of neonatal pigs and a number of parameters, including gross evidence of diarrhea, mesocoloninc edema, typhlitis, and colitis. C. difficile was isolated from 51% (66/129) of large intestines and TCd was detected in the colon contents of 50% (65/129) of the piglets. Fifty-eight percent (38/65) of TCd-positive piglets had normal to pelleted colon and rectal contents, whereas 75% (48/64) of TCd-negative pigs had gross evidence of diarrhea. Clostridium difficile toxin-positive animals were significantly more likely to have normal to pelleted feces. Edema of the mesocolon was observed in 38/65 (59%) of TCd-positive piglets. Because a high number of TCd-positive piglets (41%) lacked edema of the mesocolon and a high number of TCd-negative pigs had mesocolonic edema (51%), a statistically significant association between TCd and mesocolonic edema was not identified. Seventy-five percent (49/65) of TCd-positive piglets had colitis and 47/65 (72%) had typhlitis. The association between TCd and both colitis and typhlitis was statistically significant. Apparently healthy piglets were obtained from 5 separate sites. Because TCd was detected in the colon contents of 23/29 (79%) apparently healthy piglets obtained from 5 separate sites, and 70% of TCd-positive control pigs had colitis, C. difficile may represent an important subclinical issue in neonatal swine.

Clostridium difficile in Food and Animals: A Comprehensive Review

Zoonoses are infections or diseases that can be transmitted between animals and humans through direct contact, close proximity or the environment. Clostridium difficile is ubiquitous in the environment, and the bacterium is able to colonise the intestinal tract of both animals and humans. Since domestic and food animals frequently test positive for toxigenic C. difficile, even without showing any signs of disease, it seems plausible that C. difficile could be zoonotic. Therefore, animals could play an essential role as carriers of the bacterium. In addition, the presence of the spores in different meats, fish, fruits and vegetables suggests a risk of foodborne transmission. This review summarises the current available data on C. difficile in animals and foods, from when the bacterium was first described up to the present.