Isolation,identification and biological characteristics of Trueperella pyogenes o-riginating from milk of dairy goats with mastitis
10.16303/j.cnki.1005-4545.2025.02.09
- VernacularTitle:奶山羊乳房炎源化脓隐秘杆菌的分离鉴定及生物学特性
- Author:
Yuchen WEI
1
;
Bin WANG
;
Chenxiao WANG
;
Xindong BAI
;
Mingjin FANG
;
Yuan YUAN
;
Juan WANG
;
Zengqi YANG
Author Information
1. 西北农林科技大学动物医学院,陕西杨凌 712100
- Publication Type:Journal Article
- Keywords:
mastitis in dairy goats;
Trueperella pyogenes;
virulence genes;
minimal inhibitory con-centration;
drug resistance genes;
whole genome sequencing
- From:
Chinese Journal of Veterinary Science
2025;45(2):235-242
- CountryChina
- Language:Chinese
-
Abstract:
To investigate the distribution and biological characteristics of Trueperella pyogenes in caprine mastitis,67 milk samples from were collected from goats with mastitis in 9 dairy goat farms in the Guanzhong area of Shaanxi Province.A total of 21 strains of T.pyogenes were isolated through bacterial separation and culture.PCR amplification was conducted for 8 virulence genes of the 21 isolated strains,and the susceptibility of the strains to 10 antimicrobial drugs was tested u-sing the micro broth dilution method.Nine selected strains were subjected to genomic sequencing using Illumina Nova Seq 6000 next-generation sequencing technology,and their pathogenicity was verified by inoculating mice through the teat canal.The results of virulence gene detection showed that the positive rates of plo,cbpA,nanH,nanP,fimA,fimC-,and fimE genes among the 21 iso-lated strains were 100.0％,38.1％,52.6％,31.6％,61.9％,57.1％,and 52.4％,respectively.In con-trast,the fimG gene was not detected,which was consistent with the results of genomic compari-son by next-generation sequencing.The drug susceptibility test results showed that the susceptibil-ity rates of the isolated strains to clindamycin(CLI),ceftiofur(CEF),and vancomycin(VAN)were 100.0％,while the resistance rates to penicillin(PEN),erythromycin(ERY),sulfamethox-azole-trimethoprim(SXT),florfenicol(FFC),tetracycline(TE),gentamicin(GEN),and enroflox-acin(ENR)were 76.2％,52.1％,52.4％,52.4％,47.6％,42.9％,and 33.3％,respectively.The pro-portion of strains resistant to at least three antimicrobial drugs was 71.4％(15/21).ResFinder a-nalysis of the resistant genes identified 8 types of resistance genes in the genomes of the 9 strains,including ant(2")-Ia and ant(3")-Ia mediating aminoglycoside resistance,cmlA1 and cmx media-ting chloramphenicol resistance,erm(X)and lnu(A)mediating macrolide resistance,sul1 media-ting sulfonamide resistance,and tet(W)mediating tetracycline resistance.Except for tet(W),cm-lA,and erm(X),the other resistance genes were detected for the first time in T.pyogenes in Chi-na.In animal pathogenicity tests,mice inoculated with the isolated strains showed signs of mastitis such as redness,congestion,and inflammatory cell infiltration in the glandular tissue within 24 h,indicating that the isolated strains have pathogenicity to mouse mammary tissue.This study pro-vides preliminary insights into the biological characteristics and pathogenicity of T.pyogenes from caprine mastitis,enriching the data on its drug resistance and genomics,and offering reference and guidance for the prevention and treatment of T.pyogenes infections in large-scale dairy goat farm-ing.
