金黄色葡萄球菌细胞结合胞外青霉素酶的研究

对金黄色葡萄球菌细胞结合胞外青霉素酶研究,找出了最有利于释放细胞结合胞外酶的条件,即以MIC/2量苯唑青霉素诱导和20%MgSO_4处理。在此条件下金黄色葡萄球菌菌株75释放的细胞结合胞外青霉素酶活力为8486 u/ml,是对照的19.87倍。用此条件证实26株耐药性金黄色葡萄球菌的细胞结合青霉素酶活力在19 937～382 033 u/ml;由此释出的部分细胞结合胞外青霉素酶活力在880～13 472u/ml。其中菌株85063释出的细胞结合胞外青霉素酶活力最高,为13 472u/ml。菌株85102的释出率最高,为6.23%。

CELL-BOUND EXOPENICILLINASE IN STAPHYLOCOCCUS AUREUS

Cell-bound exopenicillinase from 26 strains of the penicillin-resistant or oxacillin-resistant S. aureus was studied. The maximum amount of the cell-bound exopenicillinase liberated from the strain 75 of S. aureus was induced with oxacillin at half amount of MIC and stimulated with 20% concentrations of MgSO_4, the specific activity being 8486u/ml about 19.87 times as much as that in control (p<0.01). It was demonstrated that there existed cell-bound penicillinase and cell-bound exopenicillinase of S. aureus under the conditions mentioned above. The activity of cell-bound penicillinase ranged from 19937 u/ml to 382033 u/ml, while the activity of cell-bound exopenicillinase ranged from 880 u/ml to 13472 u/ml. The maximum amount of the cell-bound exopenicillinase released from the strain 85063 of S. aureus was about 13472 u/ml.