凝固酶阴性葡萄球菌致病性的鉴定

目的以细菌胞外多糖黏附素（PIA）产生作为毒力指标,鉴定凝固酶阴性葡萄球菌（CNS）的致病性。方法用刚果红琼脂培养法分离CNS,用刚果红-阿里新蓝对PIA进行联合染色,同时,与采自皮肤的CNS样本作阴性对照。结果致病性CNS在刚果红琼脂培养基中菌落呈黑色,阴性对照组的菌落为红色。染色镜下观察,致病性CNS菌体着色较深,菌体表面PIA显深红色;对照组菌体无PIA而为淡红色。结论刚果红琼脂培养法和刚果红-阿里新蓝联合染色,对CNS的分离和PIA的检测有重要意义,能为CNS致病性的确定提供可靠依据。

Determination of pathogenicity of coagulase-negative staphylococci

Objective With polysaccharide intercellular adhesion (PIA) as a potential indicator of virulence,the pathogenicity of coagulase-negative staphylococci (CNS) was determined. Methods CNS strains were isolated with Congo red agar culture. Then Congo red and Alcian blue stains were used to perform combined staining for PIA with the skin CNS sample as negative control. Results A positive result of pathogenic CNS on Congo red agar (CRA) was shown as black colonies and the nega-tive control usually remained pink. After combined staining, pathogenic CNS strains with PIA positive showed as cardinal red and the negative control strain as salmon pink observed under light microscopy. Conclusion Isolation of CNS with Congo red agar culture method and detection of PIA with Congo red-Alcian blue combined staining might offer reliable experimental basis for definiting pathogenicity of CNS.