青霉素Etest法评价肺炎链球菌苯唑西林的纸片筛选试验

Evaluation of oxacillin disk test for screening Streptococcus pneumoniae by penicillin Etest method

目的青霉素Etest法评价肺炎链球菌苯唑西林的纸片筛选试验。方法对临床分离的96株肺炎链球菌非脑膜炎株,用Etest作为测定青霉素敏感性的标准方法,评价苯唑西林的纸片筛选试验的灵敏度和特异性。结果 96株肺炎链球菌非脑膜炎株,用Etest测定青霉素敏感株(PSSP)为96.9%(93/96),青霉素中度敏感株(PISP)为3.1%(3/96),未发现青霉素耐药株(PRSP)。苯唑西林纸片法初筛出16株PSSP,灵敏度为17.2%,特异性为100.0%。苯唑西林纸片法与Etest方法比较,差异有统计学意义(χ2=77,P<0.01)。结论苯唑西林纸片法作为肺炎链球菌非脑膜炎株青霉素注射剂敏感性的初筛方法灵敏度低,大部分肺炎链球菌必须用Etest等MIC方法检测。

Objective To evaluate the oxacillin disk screening test for screening Streptococcus pneumoniae by the penicillin Etest method.Methods 96 clinically isolated non-meningitis strains of Streptococcus pneumoniae were collected.The sensitivity and spe-cificity of the oxacillin disc screening test was evaluated by the penicillin Etest method as a standard method for detecting the peni-cillin susceptibility.Results Among 96 non-meningitis strains of Streptococcus pneumoniae,the penicillin-susceptible Streptococcus pneumoniae（PSSP）strains detected by the penicillin Etest method accounted for 96.9%（93/96）,the penicillin intermediate Strep-tococcus pneumoniae（PISP）strains accounted for 3.1%（3/96）and no penicillin resistant Streptococcus pneumoniae（PRSP）strain was found.But 16 PSSP strains were detected by the oxacillin disc screening test with the sensitivity of 17.2% and the specificity of 100.0%,respectively.The difference between the oxacillin disc screening test and the penicillin Etest method was statistically sig-nificant（χ2 =77,P 〈0.01 ）.Conclusion The oxacillin disc screening test has the low sensitivity for preliminarily screening non-meningitis strains of Streptococcus pneumoniae.Most of Streptococcus pneumoniae must be detected by the minimum inhibitory concentration（MIC）methods such as the penicillin Etest method.