Clostridium difficile (Cd) in Shelter Dogs: Rationale for Screening of Pets Slated for Adoption

with Cd was originally associated with prior use of antibiotics [14], however, active community-associated Cd infections that are not linked to antibiotic therapy or hospitalization have recently emerged, suggesting risk factors other than antibiotics use in Cd infections [15,16].In addition, toxigenic Cd strains were isolated from large swaths of potential sources that include pet animals [1], human food, food animals such as cattle, swine, and horses [2,3,6,17], and from the environment [18].Companion animals could play critical role in communityacquired Cd infections if they harbor any of the hyper-virulent antimicrobial-resistant toxigenic Cd strains [19].Dogs in particular, given their intimacy with humans, could be potential reservoirs for Cd infections, especially in the elderly, immunecompromised, and hospitalized individuals [20].Prevalence of Cd in sick and healthy dogs and their implication as a possible reservoir for community-acquired Cd infections was previously suggested [7,[21][22][23].Studies on the prevalence and characterization of Cd in sheltered dogs are limited; one study was conducted overseas, Germany, [24] while the other study was performed on dogs housed in temporary shelters at the University of California Veterinary Medical Hospital, Davis [21].The objective of this work was to investigate if sheltered and household dogs could be potential sources for Cd acquisition.Here, we compared the prevalence of Cd in healthy household dogs versus dogs kept in shelters for long-term/ long-term sheltered dogs.We also examined if any of the Cd isolates in dogs bore toxin associated genes. Materials and Methods Study area, gender, age, and number of dogsTwo groups of dogs, from shelters in two counties in the state of Alabama (Lee and Russell counties, AL, USA), and a third group from household dogs, in one of the above counties, were examined.Of the total 197 samples investigated, 105 were obtained from males and 92 were from females.Among the 197 dogs, Group A consisted of 70 male and female dogs (35 from each gender).These dogs were from first Humane Shelter in Lee County.Group B consisted of 60 total dogs, 36 males and 24 AbstractClostridium difficile (Cd)-associated disease is an important nosocomial bacterial infection.However, non-hospital-associated infections have been recently reported.We investigated the occurrence of Cd in apparently healthy household and in sheltered dogs.A total of 197 rectal swab samples were collected from male and female dogs from two shelters and from private homes in two counties in Alabama, USA.Eight out of the 197 samples (4.1%) were confirmed positive for Cd by latex agglutination test.Ribotyping and toxin gene characterization by PCR showed five serotypes (I-V) with 3 isolates carrying A+ B+ genes and other 3 carrying A-B+ genes.However, further analysis of the 6 toxin positive isolates with ELISA showed only 3 isolates 50% (3/6) as positive.All Cd positive samples were from sheltered dogs.Because sheltered dogs could be potential sources for Cd infections, we recommend screening of sheltered dogs for toxigenic Cd as part of a routine procedure for adoption.