Liver Abscess Associated with Streptococcus suis Serotype 4 in a Duroc Boar

JARQ : Japan Agricultural Research Quarterly
ISSN 00213551
書誌レコードID(総合目録DB) AA0068709X

A 7-month-old Duroc boar exhibited anorexia and dark-bloody diarrhea. Despite antimicrobial therapy including enrofloxacin (fluoroquinolones) and tylosin (macrolides), the boar died. Gross examination showed hepatic abscesses. Histological examination showed chronic multifocal necrotizing and suppurative hepatitis with colonies of Gram-positive cocci. Necrosis was observed in the center of affected areas. The lesions were composed of numerous neutrophils, macrophages, a few lymphocytes, and fibroblasts. Dense fibrous connective tissue surrounded these necrotizing and suppurative lesions. Several cocci were also detected in the multifocal necrotic foci in the liver. The bacteria isolated from the hepatic abscesses were confirmed to be Streptococcus suis serotype 4 based on the results of 16S rRNA gene sequencing and agglutination tests with antisera. Immunohistochemically, the cocci observed in the hematoxylin and eosin and Gram-stained sections of the liver abscess were strongly positive for S. suis serotype 4. Antimicrobial susceptibility testing showed that the isolate was resistant to third generation cephalosporins. Thus, a diagnosis of unique streptococcosis caused by S. suis serotype 4 was made. The typical clinical manifestation of S. suis infection involves meninges, endocardium, joints, and the lungs. The present boar is the first natural case of porcine liver abscess caused by S. suis serotype 4.

作成者 Koka TAKIZAWA Masahiro KUSUMOTO Toshiyuki MATSUURA Tomoko NAGAI Yoshifumi KOBAYASHI Naoto IMAI Tomoyuki SHIBAHARA
著者キーワード antimicrobial susceptibility testing gene sequencing immunohistochemistry pig streptococcosis
公開者 Japan International Research Center for Agricultural Sciences
国立情報学研究所メタデータ主題語彙集(資源タイプ) Journal Article
開始ページ 347
終了ページ 352
DOI 10.6090/jarq.52.347
言語 eng