| Popis: |
The current study was done to investigate and characterize Clostridium difficile of swine origin and compare to isolates of human origin. The overall hypothesis of the study is that C. difficile is found in high prevalences in swine and is phenotypically and genotypically similar to isolates of human origin. The study was done by collecting swine fecal samples at farrowing, nursery, and finishing stages in North Carolina and Ohio. Isolates from humans were collected from two hopitals in Ohio. Isolates were compared using antimicrobial resistance profiles, antimicrobial resistance gene detection, toxin gene detection, RFLP-Toxinotyping, and PFGE. Clostridium difficile was isolated from a most (73%) of farrowing piglets, only one nursery pig (0.47%), and no slaughter pigs. Ciprofloxacin resistance was found commonly in C. difficile of both swine (93%) and human (94%) origin. Resistance to tetracycline was also found to be high in the isolates of swine origin (59%) with 97% of these isolates found to be carrying the tetM gene and 32% the tetW gene. Metronidazole resistance was found in 1.6% and reduced susceptibility to vancomycin was found in 6.3% of isolates of human origin. The majority (89%) of isolates of swine origin were found to be Toxinotype V, a toxinotype of public health concern. Twelve percent of pigs were found to carry more than one toxinotype. The most common toxinotypes found in the isolates of human origin were toxinotype O (46%) and III (22%). A small percentage (3.1%) of these isolates were found to be toxinotype V. When comparing all isolates using PFGE, several isolates of human origin were found to cluster with isolates of swine origin, although none of these were found to be 100% similar. One cluster, found to be 88.4% similar, contained a CDC NAP 7 isolate of human origin and three isolates of swine origin, all found to be toxintoype V. The finding of similar isolates in swine and humans is a public health concern, as it is possible that contaminated food products could be a source of human infection with C. difficile. This research helps to increase the knowledge of the molecular epidemiology of C. difficile in swine as compared to humans, but more research is needed to further determine if a true relationship between these similar isolates exists. |
