The prevalence of leptospiral antibodies in dairy cows was investigated throughout Japan. The antibodies were detected by an ELISA screening test using individual bulk tank milk and a microscopic agglutination test (MAT) using serum. A total of 249 dairy farms were randomly selected for the survey, with 78 (31.3%) of the farms found to be positive for Leptospira interrogans serovar Hardjo. Of 1,510 cows randomly selected from the farms that were found to be positive in the ELISA test, 688 (45.6%) were positive for leptospiral antibodies, with the positive rate in Hokkaido (67.5%) being particularly high. The positive rate for L. interrogans serovar Hardjo was the next highest, detected in 663 cows (43.9%), followed by L. interrogans serovar Hebdomadis (38.9%). In the detection of antibodies from serum using the ELISA test, 723 (47.9%) of cows were found positive for serovar Hardjo, which corresponded well with the MAT results. Thus, the wide prevalence of leptospiral antibodies in dairy cows in Japan was confirmed using the MAT and ELISA tests, and L. interrogans serovar Hardjo was found to be the major serovar.
Six piglets with cutaneous lesions were born on a farm in Kagoshima Prefecture, Japan. The lesions manifested as papules and pustules over the entire body of each piglet. A pathological and virological analysis was performed on 5 of the affected piglets. Piglets with large multiple cutaneous lesions also showed tongue erosions. We observed hyperplasia, ballooning degeneration, eosinophilic cytoplasmic inclusions, and intranuclear vacuoles in the prickle cells of the skin and tongues of the piglets. Upon performing immunohistochemistry and electron microscopy, swinepox virus antigens and poxvirus particles were detected, respectively, in the lesions. Moreover, a polymerase chain reaction helped detect an identical sequence in the gene encoding the swinepox virus envelope protein in 2 piglets; this sequence was closely related genetically to that observed in viruses previously isolated from the United States. Based on these results, the disease was concluded to be congenital swinepox. To the best of our knowledge, this is the first report on a genetic comparison of swinepox virus in Japan.
In March 2011, broiler chickens reared on a farm in Fukuoka prefecture showed nasal discharge, respiratory rales, closed eyes and crouching. The mortality of the chickens increased. Necropsy revealed yellowish caseous exudates in the air sacs and intestinal serous membranes, and turbidity of the air sacs. Histopathologically, the tracheal mucosa was markedly thickened due to the infiltration of lymphocytes and plasma cells with the formation of germinal centers. The epithelial surface of the tracheal mucosa showed a positive reaction against Mycoplasma gallisepticum (MG) by immunohistochemical staining. MG was isolated from tissue homogenates of the trachea and yellowish caseous exudates, and an MG-specific gene was amplified by PCR in the same material and MG antibody was detected from all birds examined. On the basis of these findings, we considered a rare field case of MG infection in broiler chickens.
A Papillon with a mast cell tumor in the small intestine was treated by surgical resection. Since metastatic lesions were detected in the mesenteric lymph node and the greater omentum, vinblastine and prednisolone were commenced postoperatively. No tumor progression or metastases were observed for five months; however, carcinomatous peritonitis was detected on day 160. The regimen was changed to lomustine (CCNU). The dog showed remarkable improvement and was in good general health for approximately one year. The dog was still alive and showed no signs of recurrence on day 773, despite the discontinuation of the medication on day 521. The combination of surgical resection and postoperative chemotherapy is effective for treating gastrointestinal mast cell tumors in dogs. Of the chemotherapeutic agents, lomustine may be more effective for obtaining good control of this type of tumor.
The results of Campylobacter jejuni/coli detection obtained using the three DNA-based methods PCR, loop-mediated isothermal amplification (LAMP) and real-time PCR were compared to those obtained by conventional culture. By culturing, C. jejuni/coli was detected in 42/55 (76.4%) samples, whereas 42/55 (76.4%) were found to be positive using PCR, 49/55 (89.1%) were found to be positive using LAMP, and 50/55 (90.9%), were found to be positive using real-time PCR. The DNA-based methods were more sensitive than culturing, with three (23.1%), seven (53.8%) and eight (61.5%) of 13 culture-negative samples found to be C. jejuni/coli positive using the PCR, LAMP and real-time PCR methods, respectively. Although there were several false negative cases observed, the 5-10-fold dilution of the samples with distilled water facilitated the positive reaction. The DNA-based methods were rapid and thought to be substantially more effective in detecting C. jejuni/coli in diarrheal feces than conventional culturing.