Experimental inoculation and nose-to-nose transmission of Clostridioides difficile between weaned piglets.

In piglets, Clostridioides (C.) difficile infection presents mostly subclinical manifestation. As this agent became important in veterinary medicine due to a hypothesis of zoonosis, the objective of this study was to evaluate the transmission of C. difficile by nose-to-nose contact in young piglets. Six 20-day-old piglets were separated into three groups (infected, sentinel and control), and distributed in different isolation cabinets which allowed nose-to-nose contact only between infected and sentinel groups. The challenged group received an inoculum 106 CFU/mL of C. difficile 096 by oropharyngeal route. Rectal swab samples were daily collected for microbiological and molecular analysis. Euthanasia of all piglets was performed 18 days after challenge to evaluate anatomical, histological and microbiological lesions of the organs of these animals. The challenged and sentinel groups showed clinical signs of infection and genes encoding TcdB were detected by conventional PCR in both groups, confirming the transmission of the pathogen from the challenged to the sentinel piglets. At necropsy, tonsil, liver, spleen, mesenteric lymph nodes, ileocolic lymph nodes, jejunum, ileum, proximal colon, distal colon and cecum were collected for microbiological analysis; lesions were observed varying in degree and intensity. This study demonstrated a novel route of transmission of C. difficile between young piglets, which was proven to occur by nose-to-nose contact.

Necrotic Enteritis Caused by Clostridium perfringens in Blue and Gold Macaws (Ara ararauna).

Clostridium perfringens types A and C, which are gram-positive, anaerobic, spore-forming bacteria, can cause necrotic enteritis in birds. Although Clostridium perfringens is considered a commensal organism in the avian intestinal tract, in association with severe stress, other infectious agents, or immunosuppressive conditions, it can cause disease outbreaks. This report describes a disease occurrence of necrotic enteritis caused by C perfringens in macaws (Ara ararauna). Two adult male blue and gold macaws maintained in a zoo exhibit were presented for postmortem examinations after histories of sudden death. Based on the gross examinations and microscopic evaluation of submitted tissue from both birds, the cause of death was determined to be necrotic enteritis. Microbiologic assays followed by polymerase chain reaction analyses identified the isolated strains as C perfringens type A, indicated by only being positive for the cpa gene that encodes the α-toxin. The birds were maintained in an exhibit in which patrons can interact with the animals within their environment. Thus, organisms, such as this pathogen, may present a danger for other birds because visitors could disperse the bacterium to other parts of the zoo.