Biological Characteristics Study On Streptococcus Suis Isolated From Jiangxi Province

Streptococcus suis is the major cause of Swine Streptococcosis,porcine meningitis,sepsis,endocarditis,arthritis,and pneumonia.The presence of Streptococcus suis annually results in significant worldwide economic loss.It is also a zoonotic pathogen,meaning it provides an additional risk to public health.In this study,the distribution of serotype and virulence genotypes,antibiotic resistance,and other biological characteristics of 62 Streptococcus suis strains isolated from JiangXi Province were detected and analyzed.This research could also provide the basis of further understanding diseases and public health concerns related to Streptococcus suis.In this study,62 strains of bacterium,identificated as Streptococcus suis through cultivation,RCR,and sequencing,were isolated from sick pigs.Researchers suspected Swine Streptococcosis materials would be present.They observed a number of different sized pig farms in JiangXi.JiangXi holds the highest rate of lung separation.Most Swine Streptococcosis occurs in the presence of other pathogen infections,mainly PRRSV and PCV-2.Streptococcus suis serotype 1,2,7 and 9 were identified by PCR.The percentage of Streptococcus suis serotype 1,2 and 9 are 12.9%,35.5% and 8.1%,respectively.Unknown serotype accounted for 43.5%.No Streptococcus suis serotype 7 strains have been detected.The results showed the presence of different serotypes of Streptococcus suis infections in JiangXi,including Streptococcus suis type 2 as the most popular serotype.According to six main virulence genes(GHD,MRP,EPF,FBPS,ORF2,and SLY)62isolates of Streptococcus suis were detected by PCR.The results were as follows:GDH(62/100%),MRP(47/75.8%),/53.2%),FBPS(36/58.1%),ORF2(34/54.8%),SLY(14/22.3%).It was indicated 22 out of 62 Streptococcus suis had 10 genotypes positive in gdh+mrp+epf+fbps+orf2+sly-and gdh+mrp+epf+fbps+orf2+sly+.In addition,the rate of virulence factors in Streptococcus suis2 are higher than average.16 kinds of commonly used antibiotics were used to detect the drug sensitivity of Streptococcus suis through the K-B paper method.The results revealed 59 of Streptococcus suis isolates displayed multi-drug resistance.Resistance to tetracycline,erythromycin and doxycycline are notable,accounting for 96.78%,80.64% and 80.64%.High sensitivity to cefazolin,cefotaxime and amoxicillin,registered as 85.49%,87.1%and 85.49%,respectively.The results showed Streptococcus suis isolated from clinical sick or dead pigs as varyingly resistant to common antimicrobial drugs.