科氏葡萄球菌噬菌体的分离鉴定及其对生物被膜的清除作用OA

To address the increasing infection risk and antibiotic resistance of Staphylococcus cohnii(S.cohnii),a S.cohnii-specific bacteriophage was isolated from sewage and characterized.The phage's morphology,optimal multiplicity of infection(MOI),one-step growth curve,and biological stability were analyzed.The phage genome was sequenced and examined against the Virulence Factors and ResFinder databases to determine the presence of virulence or antibiotic resistance genes.The plaque counting method was used to evaluate the lytic effect of the phage on planktonic bacteria and its ability to remove bacterial biofilms,while the crystal violet staining method was employed to assess the phage's efficacy in eliminating extracellular polymeric substances from the bacterial biofilm.The results showed that one S.cohnii bacteriophage was isolated and named vB_ScoM-YCP,formed clear plaques 1.0-1.5 mm in diameter with regular edges and translucent halos.The optimal MOI was 0.01,the latent period 15 min,and the burst period 35 min.The phage remained stable at pH 4.0-9.0 and 20-40℃,and was resistant to 1%chloroform.Genomic analysis revealed that vB_ScoM-YCP(GenBank accession number:PQ801475.1)contained no virulence or antibiotic resistance genes.The phage significantly reduced planktonic S.cohnii populations within 2 h(P<0.01)and achieved 89.69%lysis of biofilm-embedded cells within 72 h,with a 63.80%removal rate for extracellular polymeric substances of the mature biofilms.These findings indicate that the isolated phage vB_ScoM-YCP exhibits strong lytic activity against S.cohnii and effectively removes its biofilms,enriching the phage resource library for S.cohnii.