Isolation,identification and pathogenicity of Histophilus somni from goats in Chi-na
10.16303/j.cnki.1005-4545.2025.05.12
- VernacularTitle:中国山羊源睡眠嗜组织菌(Histophilus somni)的分离鉴定及致病性
- Author:
Fuxiang LI
1
;
Huafeng GAO
1
;
Wenhua ZHAO
1
Author Information
1. 云南省畜牧兽医科学院云南省热带亚热带动物病毒病重点实验室,云南 昆明 650224
- Publication Type:Journal Article
- Keywords:
Histophilus somni;
isolation;
pathogenicity;
goat
- From:
Chinese Journal of Veterinary Science
2025;45(5):971-977,986
- CountryChina
- Language:Chinese
-
Abstract:
To identify the bacterial pathogens in a case of goat respiratory disease in Yunnan prov-ince,three Gram-negative,rod-shaped bacteria strains,YN240861,YN240862 and YN240863,were isolated from lung samples of three diseased goats with respiratory disease,and the identifications of the biochemical and the sequence similarity and phylogeny of 16S rDNA gene,and the analyses of the pathogenicity and antimicrobial susceptibility were studied.The results of the bacterial iden-tification indicated that the most biochemical characteristics of the three isolates were identical with those of the Histophilus somni(H.somni)type stain ATCC 43625T and the other reference strains of H.somni.The three strains had the 16S rDNA sequence similarity of 97.7％with H.som-ni type strain ATCC 43625T,and shared the 16S rDNA sequence similatiies of 99.4％-99.9％with the other H.somni reference strains.The three strains formed the same branch with all the H.som-ni reference strains in the 16S rDNA gene sequence phylogenetic tree.Based on these identification results,the three strains were identified as H.somni.The mouse pathogenicity test showed that each of the three strains had the median lethal dose(LD50)≤7.6×10 5 CFU in mice,which indica-ted that the three stains have higher pathogenicity to mice.The results of the antimicrobial suscep-tibility test indicated that the three strains were sensitive to ampicillin of penicillins,cefazolin and ceftriaxone of cephalosporins,chloramphenicol and florfenicol of chloramphenicols,kanamycin and gentamicin of aminoglycosides,and ofloxacin of quinolones.The strain YN240862 was resistant to sulfamethoxazole of sulfonamides.To our knowledge,this is the first isolation of Hi.somni in Chi-na,and confirmed the presence of H.somni infection in goats in China,which provides the basic da-ta for the prevention and treatment of H.somni infection in goats in China.
