Clostridium perfringens α and ß recombinant toxoids in equine immunization / Toxóides recombinantes α e ß de Clostridium perfringens na imunização de equinos

Clostridium perfringens is considered one of the main causative agents of superacute enterocolitis, usually fatal in the equine species, due to the action of the ß toxin, and is responsible for causing severe myonecrosis, by the action of the α toxin. The great importance of this agent in the equine economy is due to high mortality and lack of vaccines, which are the main form of prevention, which guarantee the immunization of this animal species. The aim of this study was to evaluate three different concentrations (100, 200 and 400µg) of C. perfringens α and ß recombinant toxoids in equine immunization and to compare with a group vaccinated with a commercial toxoid. The commercial vaccine was not able to stimulate an immune response and the recombinant vaccine was able to induce satisfactory humoral immune response in vaccinated horses, proving to be an alternative prophylactic for C. perfringens infection.(AU)

Clostridium perfringens é considerado um dos principais agentes causadores de enterocolites superagudas, geralmente fatais na espécie equina, devido à ação da toxina ß, além de ser responsável por causar quadros graves de mionecrose, pela ação da toxina α. A grande importância desses agentes na equinocultura, deve-se a elevada mortalidade e a inexistência de vacinas, principal forma de prevenção, que garantam a imunização dessa espécie animal. O objetivo deste trabalho foi avaliar três diferentes concentrações (100, 200 e 400µg) dos toxóides recombinantes α e ß de C. perfringens na imunização de equinos, bem como comparar com um grupo vacinado com um toxóide comercial. A vacina comercial não se mostrou capaz de estimular uma resposta imune e a vacina recombinante foi capaz de induzir resposta imune humoral satisfatória em equinos vacinados, provando ser uma alternativa profilática para infecção por C. Perfringens.(AU)

Changes in blood biomarkers in Arabian horses with Clostridium difficile-induced enterocolitis.

Clostridium difficile (CD) is considered a major health care problem both in developing and developed countries; frequently reported to be associated with enterocolitis and diarrhea in horses and other animals. In this study, we examined acute phase response (APR), cytokines response, neopterin (NP) procalcitonin (PCT) production and oxidative stress condition in horses and foals with C. difficile-induced enterocolitis (CDIE) and evaluated the effectiveness of these parameters as biomarkers for the disease. A total of 407 Arabian horses in 35 stables were examined between January 2017 to December 2018. Only 24 out of 407 horses showed two or more signs of CDIE. The blood level of serum amyloid A (SAA), haptoglobin (HP), proinflammatory cytokines (TNF-α, IL-6 and IL1-ß), serum malondialdehyde (MDA), PCT and NPT in horses with CDIE were higher than in healthy horses. Nevertheless, the levels of nitric oxide (NO), superoxide dismutase (SOD) and total antioxidant concentration (TAC) were considerably lower in diseased horses compared to those that were healthy. The ROC curves for eleven selected blood parameters, both in healthy horses and horses with CDIE demonstrated that all examined blood markers had significant levels of differentiation between CDIE cases and healthy controls (AUC > 87.5). The data in this study suggest that the evaluation of acute-phase proteins, cytokines, PCT, NPT, and oxidative stress biomarkers may well be used as a tool for diagnosis and assessment of CDIE and in disease pathogenesis in Arabian horses.

Clostridium difficile Enterocolitis in a Captive Geoffroy's Spider Monkey (Ateles geoffroyi) and Common Marmosets (Callithrix jacchus).

Clostridium difficile is a well-documented cause of enterocolitis in several species, including humans, with limited documentation in New World nonhuman primates. We report several cases of C. difficile-associated pseudomembranous enterocolitis, including a case in a Geoffroy's spider monkey (Ateles geoffroyi) and several cases in common marmosets (Callithrix jacchus). The histologic lesions included a spectrum of severity, with most cases characterized by the classic "volcano" lesions described in humans and several other animal species. C. difficile was isolated from the colon of the spider monkey, while the presence of toxin A or toxin B or of the genes of toxin A or B by polymerase chain reaction served as corroborative evidence in several affected marmosets. C. difficile should be considered a cause of enterocolitis in these species.

Detection of chicken interleukin-10 production in intestinal epithelial cells and necrotic enteritis induced by Clostridium perfringens using capture ELISA.

AIMS: To assess the production level of interleukin (IL)-10 inClostridium perfringens (CP)-stimulated intestinal epithelial cells (IECs) and CP-infected chickens using an antigen capture ELISA developed by mouse monoclonal antibodies against chicken IL-10. Also, to investigate which CP toxins induced IL-10 in chicken IECs stimulated with CP. METHODS AND RESULTS: Chicken IECs were stimulated with CP toxin in the absence or presence of antibodies (α-toxin or NetB) for 18 h. Expression of chicken IL-10 and IL-6 was monitored by quantitative real-time polymerase chain reaction. Serum and jejunum samples were collected from CP-infected chickens at 9 days post-infection and expression of IL-10 and IL-6 was analyzed. IL-10 production was detected by antigen capture ELISA in chicken IECs stimulated with CP and in serum samples collected from CP-infected birds. The mRNA levels were consistent with the results of antigen capture ELISA. CONCLUSION: CP induced IL-10 production in chicken IECs. Increased IL-10 production was detected in CP-stimulated chicken IECs and in serum collected from CP-infected birds, using antigen capture ELISA. Antigen capture ELISA could be a useful tool to monitor IL-10 production in chicken disease.

Survival and prevalence of Clostridium difficile in manure compost derived from pigs.

Pigs, particularly piglets, have been identified as reservoir hosts of Clostridium difficile. To examine the survival ability of this pathogen in pig feces-based manure compost, C. difficile spores, which were prepared to contain as few vegetative cells as possible, were artificially inoculated into pig feces and incubated at different temperatures. While C. difficile survived in the feces incubated at temperatures below 37 °C for over 30 days, cell numbers gradually decreased at thermophilic temperatures (over 55 °C; p < 0.05). Next, to clarify the prevalence of C. difficile in field manure compost, we isolated and characterized C. difficile from the final products of manure compost products of 14 pig farms. A total of 11 C. difficile strains were isolated from 5 of 14 (36% positive rate) samples tested. Of these 11 strains, 82% were toxigenic, with ribotype 078 being the most prevalent. Thus, the application of composted manure to land therefore poses a possible risk of C. difficile transfer to the food chain.

Clostridium difficile Infection in Production Animals and Avian Species: A Review.

Clostridium difficile is the leading cause of antibiotic-associated diarrhea and colitis in hospitalized humans. Recently, C. difficile infection (CDI) has been increasingly recognized as a cause of neonatal enteritis in food animals such as pigs, resulting in stunted growth, delays in weaning, and mortality, as well as colitis in large birds such as ostriches. C. difficile is a strictly anaerobic spore-forming bacterium, which produces two toxins A (TcdA) and B (TcdB) as its main virulence factors. The majority of strains isolated from animals produce an additional binary toxin (C. difficile transferase) that is associated with increased virulence. C. difficile is ubiquitous in the environment and has a wide host range. This review summarizes the epidemiology, clinical presentations, risk factors, and laboratory diagnosis of CDI in animals. Increased awareness by veterinarians and animal owners of the significance of clinical disease caused by C. difficile in livestock and avians is needed. Finally, this review provides an overview on methods for controlling environmental contamination and potential therapeutics available.

Zoonotic potential of the Clostridium difficile RT078 family in Taiwan.

Clostridium difficile is the major cause of nosocomial diarrhea. We have previously demonstrated that in southern Taiwan, severe C. difficile-associated diarrhea (CDAD) cases were due to the C. difficile RT 126 strain infection, indicating the arrival of an epidemic C. difficile clone in southern Taiwan. RT126 has a close genetic relationship with RT078. However, the RT078 family is the predominant strain of C. difficile in animals worldwide, particularly in swine. In this study, we surveyed C. difficile strains isolated from swine at several farms in Taiwan from August 2011 to March 2015. We found that all swine strains, namely RT078 (32.5%, 37 of 114), RT126 (28.9%, 33 of 114) and RT127 (37.7%, 43 of 114), belonged to the toxigenic RT078 family. All strains had high gyrA mutation rate (57.9%, 66/114), which was linked to quinolone resistance. Notably, Rep-PCR revealed that 3 RT078 animal strains had the same fingerprint as human RT078 clinical isolates; their phylogenic relationship was closely related to the whole gene sequences of tcdB, thus suggesting zoonotic potential for C. difficile infection in Taiwan.

Determination of the extent of Clostridium difficile colonisation and toxin accumulation in sows and neonatal piglets.

Clostridium difficile is an important spore-forming, opportunistic pathogen in animal husbandry and health care. In pig farming, only neonatal piglets are affected, and diarrhoea and necrotising lesions are common symptoms leading to dehydration and in some cases death. This study aimed at the assessment of the quantitative development of C. difficile colonisation in neonatal piglets by determining the shedding of spores and C. difficile toxins A (TcdA) and B (TcdB) concentrations in sow (n = 5-6) and piglet pen faeces (n = 5-6) at different time points. Spores were quantified on selective agar plates and toxins using ELISA method. C. difficile was not detected in the faeces of all but one sow during the perinatal period. Faeces of 2- and 4-day-old piglets contained 0.65 log cells/g and 5.88 log cells/g of C. difficile, respectively. Toxins were detected on day 4 at a concentration of 2.13 log ng/g (TcdA) and 2.06 log ng/g (TcdB). On day 6, concentration of C. difficile reached 6.14 log CFU/g and toxins 2.02 log ng/g (TcdA) and 2.20 log ng/g (TcdB). Two-week-old piglets showed 4.72 log CFU/g of C. difficile but toxins could not be detected. At 21 days of age, both C. difficile and toxins were undetectable. The concentration and the prevalence of C. difficile were positively associated with the prevalence of toxins in piglets. A very short time window for colonisation by C. difficile, including toxin-producing strains can be observed in neonatal piglets. The significance for animal health and the risk of a carrier status need to be addressed in future studies.

Effect of a probiotic on prevention of diarrhea and Clostridium difficile and Clostridium perfringens shedding in foals.

BACKGROUND: Up to 60% of foals develop diarrhea within 6 months after birth. Preventive measures are limited but potentially probiotics could be used. OBJECTIVE: To evaluate the effect of a newly designed probiotic on the incidence of foal diarrhea in a randomized field trial. ANIMALS: Seventy-two healthy neonatal foals. METHODS: Randomized, placebo-controlled field trial. Foals were administered a placebo or probiotic for 3 weeks and monitored for an additional week. A total of 3 fecal samples were taken from each foal at biweekly intervals. Statistical modeling was applied for comparison of incidence and duration of diarrhea and fecal shedding of Clostridium perfringens and Clostridium difficile between treatment and age groups. RESULTS: The overall incidence of diarrhea was 41 of 72 (59%) and did not differ (P = 0.37) between treatment groups. Foals treated with probiotics were more likely to develop diarrhea requiring veterinary intervention (P = 0.007). Age had a significant effect on incidence of diarrhea (P < 0.001); foals 8-15 days old having the highest probability of developing diarrhea. Duration of diarrhea and soft feces were not significantly different between groups. The prevalence of C. perfringens shedding was 55% with no difference between treatment groups (P = 0.23). The prevalence of C. difficile shedding was 11%. CONCLUSION AND CLINICAL IMPORTANCE: There was no benefit of administering a 3-week course of probiotics, but potential adverse effects were noted. Whether the probiotics lacked a clinical effect, or the choice of strains or dose was inadequate, is unknown. Clostridial shedding was not influenced by probiotics despite in vitro activity of probiotics.

Prevalence and risk factors associated with Clostridium difficile shedding in veal calves in Italy.

The aim of this study is to describe the prevalence and risk factors of Clostridium difficile shedding in six farms belonging to two companies in Northern Italy. Four hundred and twenty veal calves, randomly selected and individually identified, were sampled three times: at 0-16, 90-120, and 150 days after introduction. C. difficile was isolated at least once from 87 out of the 420 calves (20.7%). The prevalence of shedding was 20.24% at the first sampling and dropped to 0.72% at the second sampling. None of the samples obtained at 150 days tested positive. Sampling of cecal contents and carcass swabs at slaughter was stratified according to the herd of origin of the animals. C. difficile was never isolated at slaughter, excluding a prevalence higher than 3.5% on the basis of previous investigations. Therefore, in this work, the veal calf could not be confirmed as a potential source of C. difficile for the consumer. Eight different ribotypes (RT) have been described, but the vast majority of the isolates (87.8%) belonged to three ribotypes only: RT-078, RT-012 and RT-126, which are also among the most common of the ribotypes detected in humans in Europe. Most isolates, and all the RT-078 isolates, harbored genes coding for toxins A and B, the binary toxin, and showed a deletion in the gene encoding toxin C, suggesting that the veal calf was a reservoir for epidemic hyper-virulent strains. A correlation between age and shedding was found: the odds ratio (OR) ranged from 2.79 for 36-45 days of age to 4.57 for 13-28 days of age. The presence of diarrhea at first sampling was significantly associated with the recovery of C. difficile in feces (OR 3.26). A correlation was found between the administration of antimicrobials and shedding: an increased risk was shown when the number of antimicrobials used was higher than 4 (OR 4.02) or 5-6 (OR 5.83) or when polymyxin E or beta-lactams were administered.

Faecal shedding of antimicrobial-resistant Clostridium difficile strains by dogs.

OBJECTIVES: To longitudinally assess the shedding of antimicrobial resistant Clostridium difficile strains by clinically healthy dogs raised at breeding facilities. METHODS: 18 puppies from three different litters (#1, 2 and 3) were sampled weekly from parturition to day 20-55 postpartum. Faecal samples from the mothers of litters #2 and 3 were also available for analysis. Bacterial isolates were ribotyped, tested for in vitro antimicrobial susceptibility and further characterised. RESULTS: C. difficile was recovered from all sampled animals of litters #1 and 2, and a third of puppies from litter #3, but marked differences in C. difficile recovery were detected in different age groups (0-100%). Recovered PCR ribotypes included 056 (22 isolates), 010 (6 isolates), 078 and 213 (2 isolates each), and 009 and 020 (1 isolate each). Different ribotypes were shed by four individual animals. Regardless of their origin and ribotype, all isolates demonstrated full resistance to levofloxacin. Additionally, all but one isolate (belonging to ribotype 078) were resistant to ertapenem, and all ribotype 010 isolates displayed high-level resistance to clindamycin, clarithromycin and erythromycin. A single ribotype 078 isolate showed metronidazole heteroresistance. CLINICAL SIGNIFICANCE: Healthy dogs can shed antimicrobial-resistant C. difficile strains.

Shedding of Clostridium difficile PCR ribotype 078 by zoo animals, and report of an unstable metronidazole-resistant isolate from a zebra foal (Equus quagga burchellii).

Clostridium difficile is an emerging and potentially zoonotic pathogen, but its prevalence in most animal species, including exhibition animals, is currently unknown. In this study we assessed the prevalence of faecal shedding of C. difficile by zoo animals, and determined the ribotype, toxin profile and antimicrobial susceptibility of recovered isolates. A total of 200 samples from 40 animal species (36.5% of which came from plains zebra, Equus quagga burchellii) were analysed. C. difficile was isolated from 7 samples (3.5% of total), which came from the following animal species: chimpanzee (Pan troglodytes troglodytes), dwarf goat (Capra hircus), and Iberian ibex (Capra pyrenaica hispanica), with one positive sample each; and plains zebra, with 4 positive samples from 3 different individuals. Most recovered isolates (4/7, 57.1%) belonged to the epidemic PCR ribotype 078, produced toxins A and B, and had the genes encoding binary toxin (i.e. A(+)B(+)CDT(+) isolates). The remaining three isolates belonged to PCR ribotypes 039 (A(-)B(-)CDT(-)), 042 (A(+)B(+)CDT(-)) and 110 (A(-)B(+)CDT(-)). Regardless of their ribotype, all isolates displayed high-level resistance to the fluoroquinolones ciprofloxacin, enrofloxacin and levofloxacin. Some isolates were also resistant to meropenem and/or ertapenem. A ribotype 078 isolate recovered from a male zebra foal initially showed in vitro resistance to metronidazole (MIC ≥ 256 µg/ml), but lost that trait after subculturing on non-selective media. We conclude that zoo animals belonging to different species can carry ribotype 078 and other toxigenic strains of C. difficile showing resistance to antimicrobial compounds commonly used in veterinary and/or human medicine.

Postoperative Clostridium difficile infection with PCR ribotype 078 strain identified at necropsy in five Thoroughbred racehorses.

Clostridium difficile is an important cause of acute enterocolitis in horses. We describe five cases of C difficile infection occurring postoperatively in Thoroughbred racehorses. Following diarrhoea or colic accompanied by a marked increase in packed cell volume (to ≥60 per cent) and leucopenia (≤4000 cells/µl) within two to four days after surgery in all five horses, four of them died or were euthanased because of colitis or severe diarrhoea. In these four horses, necrotising entero-typhlo-colitis was revealed by postmortem examination, and C difficile was recovered from the contents of the small and/or large intestine. The remaining horse was euthanased because of marked decline in general condition and the presence of a lung abscess, from which C difficile was isolated. The horse had had severe postoperative diarrhoea before the onset of respiratory disorder; laboratory tests for C difficile were not performed on the faeces. All C difficile isolates were toxin-A-positive, toxin-B-positive and actin-specific ADP-ribosyltransferase (CDT)-positive. The isolates were indistinguishable by pulsed field gel electrophoresis analysis, PCR ribotyping, and slpA sequence typing, and the slpA sequences and PCR ribotype patterns were identical to those of known PCR type 078. This case sequence might have been healthcare-associated infection, although there was about a four-month interval between each disease onset.

Nontoxigenic Clostridium difficile protects hamsters against challenge with historic and epidemic strains of toxigenic BI/NAP1/027 C. difficile.

Nontoxigenic Clostridium difficile (NTCD) has been shown to prevent fatal C. difficile infection in the hamster model when hamsters are challenged with standard toxigenic C. difficile strains. The purpose of this study was to determine if NTCD can prevent C. difficile infection in the hamster model when hamsters are challenged with restriction endonuclease analysis group BI C. difficile strains. Groups of 10 hamsters were given oral clindamycin, followed on day 2 by 10(6) CFU of spores of NTCD strain M3 or T7, and were challenged on day 5 with 100 CFU of spores of BI1 or BI6. To conserve animals, results for control hamsters challenged with BI1 or BI6 from the present study and controls from previous identical experiments were combined for statistical comparisons. NTCD strains M3 and T7 achieved 100% colonization and were 100% protective against challenge with BI1 (P ≤ 0.001). M3 colonized 9/10 hamsters and protected against BI6 challenge in the colonized hamsters (P = 0.0003). T7 colonized 10/10 hamsters, but following BI6 challenge, cocolonization occurred in 5 hamsters, 4 of which died, for protection of 6/10 animals (P = 0.02). NTCD colonization provides protection against challenge with toxigenic BI group strains. M3 is more effective than T7 in preventing C. difficile infection caused by the BI6 epidemic strain. Prevention of C. difficile infection caused by the epidemic BI6 strain may be more challenging than that of infections caused by historic BI1 and non-BI C. difficile strains.

Novel molecular type of Clostridium difficile in neonatal pigs, Western Australia.

Clostridium difficile causes neonatal enteritis in piglets; strains of PCR ribotype 078 are most commonly identified. We investigated C. difficile prevalence in piglets in Australia and isolated a novel strain with a unique pathogenicity locus. In a mouse infection model, this strain produced more weight loss than did a ribotype 078 strain.

Presence of Clostridium difficile PCR ribotype clusters related to 033, 078 and 045 in diarrhoeic calves in Germany.

This study provides data on the distribution and relationship of C. difficile PCR ribotypes in diarrhoeic calves in Germany. C. difficile was isolated from 176 of 999 (17.6 %) faecal samples or swabs of diarrhoeic calves from 603 farms collected between January 2010 and August 2012 by eight federal laboratories of six states. Strains were assigned to 17 PCR ribotypes. PCR ribotypes 033 (57 %), 078 (17 %) and 045/FLI01 (closest match to 045 in the WEBRIBO database; 9 %) were found the most frequently. Nine per cent of all culture-positive tested animals shed more than one multiple locus variable number tandem repeat analysis (MLVA) or PCR ribotype. Eight PCR ribotypes with related profiles (including 033, 078 and 045/FLI01) representing 92 % of all isolates were grouped into three clusters. Molecular relatedness was supported by the absence of the MLVA locus A6Cd only in clustered strains and identical toxin gene profiles for strains within each cluster. Previously reported mulitilocus sequence typing analysis for PCR ribotypes that were also recovered in this study found identical sequence types and a tcdC deletion (Δ39 bp) for 033, 045, 078 and 126 (ST-11), confirming this clustering. A different geographical occurrence of PCR ribotypes was shown for cluster 033 (found more frequently in southern Germany) and 045 (found more frequently in northern Germany). This study showed that clusters of C. difficile PCR ribotypes related to 033, 078 and 045 are predominant in diarrhoeic calves in Germany. The high number of strains belonging to PCR ribotype 078 demonstrated that diarrhoeic calves are also potential reservoirs for human pathogenic C. difficile strains.

Protective effect of bifidobacteria in an experimental model of Clostridium difficile associated colitis.

The aim of this study was to evaluate the ability of Bifidobacterium strains to prevent the effects associated with Clostridium difficile infection in a hamster model of enterocolitis. After clindamycin treatment (30 mg/kg), animals were infected intragastrically with C. difficile (5×108 CFU per animal). Seven days prior to antibiotic administration, probiotic treatment was started by administering bacterial suspensions of bifidobacteria in drinking water. Strains CIDCA 531, CIDCA 5310, CIDCA 5316, CIDCA 5320, CIDCA 5323 and CIDCA 5325 were used. Treatment was continued during all the experimental period. Development of diarrhoea, enterocolitis and mortality were evaluated. All the infected animals belonging to the placebo group developed enterocolitis (5/5) and only two dead (2/5) whereas in the group administered with Bifidobacterium bifidum strain CIDCA 5310 the ratio of animals with enterocolitis or dead decreased significantly (1/5 and 0/5 respectively). Biological activity of caecum contents was evaluated in vitro on Vero cells. Animals treated with strain CIDCA 5310 presented lower biological activity than those belonging to the placebo group. The present study shows the potential of selected strains of bifidobacteria to antagonise, in vivo, the virulence of C. difficile.

Detection of Clostridium difficile in small and medium-sized wild Mammals in Southern Ontario, Canada.

We sampled 325 small and medium-sized wild mammals in Ontario, Canada in 2007 and 2010 to determine the prevalence and characteristics of Clostridium difficile in wild mammals living in proximity to captive wildlife and livestock. Clostridium difficile was isolated from five of 109 animals (4.6%) on four of 25 farms (16%), but was not isolated from any of the 216 samples from raccoons (Procyon lotor) living on the grounds of the Toronto Zoo. The positive animals included two raccoons from one beef farm, one raccoon from a different beef farm, one raccoon from a swine farm, and a shrew (Blarina brevicauda) from a dairy farm. None had evidence of gastrointestinal disease. Three of the five isolates were toxinotype variants (II, IV, and XIII) that are rarely identified in humans and domestic animals. The other two were toxinotype 0, a common toxinotype in humans and animals; however, all five isolates were of different ribotypes. None of the recovered ribotypes were recognized as ribotypes present in the authors' reference library of over 3,000 human and domestic animal C. difficile isolates. Neither the public health nor the animal health relevance of these findings is clear. It is not known whether C. difficile is a pathogen of small and medium-sized wild mammals, although the susceptibility of various laboratory species suggests it could cause disease.

Clostridium difficile-associated diarrhea in an ocelot (Leopardus pardalis).

The aim of this study is to report a case of Clostridium difficile-associated diarrhea in an ocelot (Leopardus pardalis) in the state of Mato Grosso do Sul, Brazil. The animal, a 24-month-old male, was referred to the Centro de Reabilitação de Animais Silvestres (CRAS) with a history of having been run over and tibia and fibula fractures. After a surgery to repair the fractures, the ocelot underwent antibiotic therapy with two doses of sodium cefovecin, during which he presented with diarrhea. A stool sample was positive for A/B toxins by a cytotoxicity assay, and a toxigenic strain of C. difficile was isolated. No other enteropathogens were detected. The association between the history, clinical signs and laboratory exams confirmed the diagnosis of C. difficile-associated diarrhea. The present report confirms C. difficile as a potential pathogen for wild felids and suggests that the C. difficile-associated diarrhea should be considered in diarrhea cases, especially when the clinical signs began after antimicrobial use.

Clostridium difficile infection in humans and piglets: a 'One Health' opportunity.

Clostridium difficile causes infectious diarrhoea in humans and animals. It has been found in both diarrhoeal and non-diarrhoeal pigs, horses and cattle, suggesting a potential reservoir for human insection, and in 20-40 % of meat products in Canada and the USA, suggesting the possibility, albeit not proven, of food-borne transmission. Although it is not yet completely clear, it is likely that excessive antimicrobial exposure is driving the establishment of C. difficile in animals, in a manner analogous to human infection, rather than the organism just being normal flora of the animal gastrointestinal tract. PCR ribotype 078 is the most common ribotype of C. difficile found in pigs (83 % in one study in the USA) and cattle (up to 100 %) and this ribotype is now the third most common ribotype of C. difficile found in human infection in Europe. Human and pig strains of C. difficile are genetically identical in Europe confirming that a zoonosis exists. Rates of community-acquired C. difficile infection (CDI) are increasing world wide, a fact that sits well with the notion that animals are a reservoir for human infection. Thus, there are three problems that require resolution: a human health issue, an animal health issue and the factor common to both these problems, environmental contamination. To successfully deal with these recent changes in the epidemiology of CDI will require a 'one health' approach involving human health physicians, veterinarians and environmental scientists.