葡萄球菌生物膜的形成及影响因素

目的了解临床标本中葡萄球菌形成生物膜的状况，及葡萄糖、乙醇、氯化钠对生物膜形成的影响。方法采用刚果红、微量平板法检测生物膜形成及葡萄糖、乙醇、氯化钠对生物膜形成的影响。结果刚果红法检测金黄色葡萄球菌(金葡菌)、凝固酶阴性葡萄球菌(CNS)生物膜阳性率分别为26．2％和12．7％；生物膜半定量法，金葡菌：普通肉汤、0．25％葡萄糖、2％、4％乙醇、2％、4％氯化钠阳性率分别为14．7％、29．6％、32．7％、19．6％、13．1％和14．6％；CNS分别为13．9％、27．8％、26．5％、18．5％和21．5％。结论临床标本葡萄球菌相当一部分能产生生物膜，葡萄糖、乙醇能促进生物膜形成。

Biofilm formation by Staphylococcus and influencing factors

Objective To investigate the biofilm formation by clinical staphylococcal isolates and the effects of glucose, alcohol and NaCl on biofilm formation. Methods Biofilm-forming ability was determined by Congo red agar (CRA) and a semi-quantitative microtiter assay using trypticase soy broth. Glucose, alcohol and NaCl were added to the medium separately to test their effect on biofilm formation by staphylococcal isolates. Results Biofilm formation was positive by 26.2% of S. aureus, and 12.7% of coagulase-negative Staphylococcus (CNS) isolates as detected by CRA. The positive rate of biofilm-forming by S. aureus in TSB, TSB + 0.25% glucose, TSB + 2% alcohol, TSB + 4% alcohol, TSB + 2% NaCl and TSB + 4% NaCl were 14.7%, 29.6%, 32.7%, 19.6%, 13.1% and 14.6% respectively. As for CNS isolates, the positive rates in corresponding media were 13.9%, 27.8%, 26.5%, 22.7%, 18.5% and 21.5% respectively.Conclusions Certain proportion of S. aureus and CNS clinical isolates could form biofilm. Glucose and alcohol can facilitate biofilm formation by Staphylococcus.