Immunohistochemical and molecular analysis of Pasteurella multocida in a rabbit with suppurative pleuropneumonia.

A 1-month-old rabbit, imported as a pet by a distributor, died suddenly in the quarantine period in Japan due to suppurative pleuropneumonia. A bacterial isolate from its right lung was identified as Pasteurella multocida serotype A: 11. The isolate was classified as ST204 using the RIRDC scheme of multilocus sequence typing, suggesting that the isolate was genetically related to European isolates of the same sequence type listed in the PubMLST database and not to four other isolates that originated from past imported rabbits. In the immunohistochemical assay, an antiserum recognizing the somatic serotype 11 antigen generated from chicken could specifically detect P. multocida, indicating that the antiserum for somatic serotyping was useful for immunohistochemical diagnosis of rabbit pasteurellosis.

Bovine peritonitis associated with Mannheimia haemolytica serotype 2 in a three-day-old Japanese Black calf.

A Japanese Black calf became dehydrated on the first day of life and died on the third day. Gross examination revealed a large amount of yellowish-brown serous fluid in the abdominal cavity and whitish-yellow fibrin in the serosa of the abdominal organs. Patchy red spots were observed throughout the peritoneum, and the outer membrane of the umbilical arteries was dark red. Bacteriologically, Mannheimia haemolytica serotype 2 was isolated from the umbilical arteries and vein, liver, and kidney. Histopathology revealed inflammation with M. haemolytica serotype 2 in the outer membrane of the umbilical arteries and in the serosa of the bladder and intestinal tract. This is the first case of bovine peritonitis with histopathologic and immunohistochemical identification of M. haemolytica.

Bovine esophageal and glossal ulceration associated with Pseudomonas aeruginosa and Fusobacterium spp. in a 10-month-old Holstein heifer.

An underweight 10-month-old Holstein heifer presented with anorexia and ananastasia and was euthanized. Postmortem examination revealed extensive ulceration in the esophagus, tongue, and omasum. Histopathological examination revealed severe necrotic esophagitis, glossitis, and omasitis. Many Gram-negative bacilli were detected throughout the necrotic area in the digestive tract; these were identified as Pseudomonas aeruginosa on the basis of isolation tests, molecular examinations, and immunohistochemistry. Gram-negative long filamentous organisms in the superficial layers of the necrotic lesions reacted positively with antibodies against Fusobacterium necrophorum subsp. necrophorum. Thus, the necrotic lesions were confirmed to be associated with P. aeruginosa and Fusobacterium spp. This is the first detection of P. aeruginosa in bovine esophageal and glossal ulcers associated with Fusobacterium spp.