Japan International Research Center for Agricultural Sciences | JIRCAS

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

Japan Agricultural Research Quarterly
ISSN
00213551
NII recode ID (NCID)
AA0068709X
Full text

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.

Date of issued2018-10-01
CreatorKoka TAKIZAWAMasahiro KUSUMOTOToshiyuki MATSUURATomoko NAGAIYoshifumi KOBAYASHINaoto IMAITomoyuki SHIBAHARA
Subjectantimicrobial susceptibility testinggene sequencingimmunohistochemistrypigstreptococcosis
PublisherJapan International Research Center for Agricultural Sciences
Dates2018-10-09
NII resource type vocabularyJournal Article
Volume52
Issue4
spage347
epage352
DOI10.6090/jarq.52.347
Languageeng