畜牧与兽医2026，Vol.58Issue(5)：89-98,10.
1株产金属β-内酰胺酶的血清3型ST117猪链球菌的生物学特性
The biological characteristics of a serotype 3,ST117 Streptococcus suis strain that produces MBLs
摘要
Abstract
One Streptococcus strain was isolated from the lung tissue of diseased pigs,and its molecular typing identification was performed through morphological observation,16S rRNA gene sequencing,and multilocus sequence typing(MLST).The pathogenicity and drug resist-ance of the isolated strain were studied via mouse infection experiments,virulence gene screening,biofilm formation ability tests,and drug sensitivity tests on antibiotics and traditional Chinese medicines(TCMs).The results showed that the isolated strain was Gram-positive,with oval-shaped bacterial cells arranged in chains observed under electron microscopy.PCR and 16S rRNA gene phylogenetic tree analysis iden-tified it as Streptococcus suis serotype 3,designated as Streptococcus suis GZYZ0831.The sequence type of isolate GZYZ0831 was ST117,which carried five virulence genes:the surface antigen gene(sao),the bacterial transferrin-binding protein gene(Tbp),the glyceraldehyde-3-phosphate dehydrogenase gene(GAPDH),the virulence-associated sequence second open reading frame(orf2),and the muramidase-released protein gene(mrp);and which exhibited α-hemolysis.Infection in mice caused varying degrees of pathological lesions in multiple organs including the lungs,spleen,and liver.GZYZ0831 was a multidrug-resistant strain producing metallo-β-lactamases(MBLs),carry-ing the resistance genes blaTEM and tetO.It possessed resistance to 17 antibiotics,including azithromycin,erythromycin,clarithromycin,and gentamicin,but was sensitive to the Chinese herbal medicines Coptidis rhizoma and Isatidis radix.This study systematically analyzed the biological characteristics of Streptococcus suis serotype 3 ST117 strain,providing scientific basis for research on the pathogenic and drug re-sistance mechanisms of Streptococcus suis,and serving as reference for the formulation of TCMs prevention and control strategies against Strep-tococcus suis infection.关键词
猪链球菌/血清型3型/ST117型/生物学特性/耐药性/中药Key words
Streptococcus suis/serotype 3/serotype ST117/biological characteristics/drug resistance/Chinese herbal medicine分类
农业科技引用本文复制引用
闫一心,雷连成,任林柱,钱晶,张付贤,梁瑶瑶,高庭颢,杨荣荣,张启文,李芃绪,徐梦然,袁紫婧,项维..1株产金属β-内酰胺酶的血清3型ST117猪链球菌的生物学特性[J].畜牧与兽医,2026,58(5):89-98,10.基金项目
湖北省重大科技专项(2024BBA004) （2024BBA004）
