Accuracy of revising the results of drug sensitivity detection by experts in VITEK2 automatic microbial analysis system

ObjectiveTo evaluate the accuracy of the modified drug sensitivity results of VITEK2 analysis system and to determine whether the drug sensitivity results can meet the clinical needs.

MethodsA total of 46 strains of Escherichia coli, 29 strains of Klebsiella pneumoniae and 12 strains of Proteus mirabilis were detected by VITEK2 test card method.Ceftazidime, cefepime and aztreonam were detected by K-B method.The results of VITEK2 test-card method were compared with reference method-K-B method.

ResultsWith two methods for ceftazidime, cefepime and aztreonam, the drug sensitivity coincidence rates were 63.0%, 47.8% and 58.7% for Escherichia coli, 37.9%, 41.4% and 34.5% for Klebsiella pneumoniae, 91.7%, 83.3% and 100.00% for Proteus mirabilis, respectively.The largest VME of Escherichia coli was 30.4% to cefepime, those of Klebsiella pneumoniae was 44.8% to cefepime, those of Proteus mirabilis was 8.3% to cefepime.There was no significant difference in the positive rate of ESBLs confirmation test (P>0.05).

ConclusionK-B method should be used to confirm the test results of VITEK2 analysis system and modified by AES, and the expert system should not be blindly used to correct the results.The results of VITEK2 analysis system or K-B method should be reported according to the clinical efficacy and the results of drug sensitivity should be evaluated at the same time.