An outbreak of septicemic listeriosis associated with diarrhea in lactating          dairy cows

Kenta YAMASAKI, Koutaro NAKAMURA, Shoya TAKAKI, Katsuki TANAKA, Akiko UEMATSU, Michiko KODANI, Yasumitsu MASUDA, Yoichi INOUE, Naoki YAMAMOTO, Akira GOTO, Keiichi HISAEDA, Yasunori SHINOZUKA, Tomoyuki SHIBAHARA, Tsuneyuki MASUDA

In April 2020, an outbreak of diarrhea occurred in lactating cows at a dairy farm in the          Tottori Prefecture. Five cows died, and Listeria monocytogenes was          isolated from the liver, spleen, kidney, and jejunum of one affected cow that was          subjected to bacteriological examination. Pathological examination revealed liver          necrosis. Histopathologically, the primary lesions were characterized by multifocal          necrotizing hepatitis. Small bacilli were immunohistochemically identified within the          necrotic hepatic lesions, as well as the jejunal villi and central lacteals. The diagnosis          was confirmed as septicemic bovine listeriosis. Subsequently, five L.            monocytogenes-suspected abortions and multiple cases of mastitis occurred on          the farm. The L. monocytogenes strains isolated from the affected cow and          the abortion and mastitis cases were all serotype 4b; their sequence type, determined by         multi-locus sequence typing, was ST1, and their clonal complexes were CC1. This case was          considered an extremely rare outbreak in which the same strain of L.            monocytogenes caused diverse symptoms, such as septicemia and diarrhea.

Journal of Veterinary Medical Science                        

Japanese Society of Veterinary Science

88

7

1017

1023

https://doi.org/10.1292/jvms.26-0093