Genome sequencing and biological characteristics analysis of a Streptococcus dys-galactiae from yak
10.16303/j.cnki.1005-4545.2025.07.10
- VernacularTitle:1株牦牛源停乳链球菌全基因组测序及生物学特性分析
- Author:
Wenjing CHENG
1
;
Tian NIU
;
Shuai YANG
;
Tingting LIU
;
Hongcai MA
;
Jiangyong ZENG
;
Lihong ZHANG
;
Junjie HU
Author Information
1. 甘肃农业大学动物医学院,甘肃兰州 730070;甘肃农业大学动物医学院甘肃省动物生殖生理及繁殖调控重点实验室,甘肃兰州 730070
- Publication Type:Journal Article
- Keywords:
yak;
Streptococcus dysgalactiae;
drug resistance;
pathogenicity;
whole genome sequen-cing
- From:
Chinese Journal of Veterinary Science
2025;45(7):1426-1436
- CountryChina
- Language:Chinese
-
Abstract:
This study aims to understand the biological characteristics of Streptococcus dysgalacti-ae of yak origin.Bacterial isolation and identification,drug susceptibility test,virulence gene test and pathogenicity test were carried out on milk samples of yaks from Naqu City to evaluate the bi-ological characteristics of the isolated strains.Meanwhile,molecular biological information such as virulence factors and drug resistance genes were analyzed by whole genome sequencing,and viru-lence genes were verified by PCR.The results showed that a strain of Streptococcus dysgalactiae was isolated from the milk of yak,and its colony morphology was pinpoint size,smooth edge and milky white.This strain is sensitive to many antibiotics(penicillin G,cephalosporin,ciprofloxacin,tetracycline,erythromycin,etc.).Virulence gene test results showed that the strain carries six key virulence genes(cyl,eno,scpB,bca,bac and napr),which may be closely related to its pathoge-nicity.In the pathogenicity test,the mice were listless and less active after infection,but no death occurred during the observation period.The pathological changes of spleen,kidney,liver and lung tissue were found,suggesting that the strain had certain pathogenic potential but not high lethali-ty.Whole genome sequencing data showed that the gene length of this strain was 4 079 280 bp,the GC content was 39.41％,3 964 coding genes were predicted,604 of which were annotated as viru-lence factors,and another 28 gene mutations may enhance its pathogenic ability.Through annota-tion of CARD database,two Pat A resistance genes and two lmrp resistance genes were found,re-vealing their potential resistance mechanism.Through whole genome sequencing technology and bioinformatics analysis method,this study revealed the genomic characteristics,drug resistance and pathogenicity mechanism of Streptococcus dysgalactiae of yak origin.The findings provide impor-tant scientific evidence for further exploration of the pathogenicity,drug resistance mechanisms,and molecular evolution of yak-derived Streptococcus agalactiae.
