Laboratory Medicine ›› 2024, Vol. 39 ›› Issue (3): 243-248.DOI: 10.3969/j.issn.1673-8640.2024.03.006

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Rapid bacterial identification and drug susceptibility test of blood culture-positive samples

LI Anqi, ZHANG Shuya, HE Shanna, CHEN Qiaoqiao, LÜ Qi, LÜ Wanfei, LI Chunxian, WANG Weihua, ZHENG Lin()   

  1. Department of Clinical Laboratory,the First Affiliated Hospital of Ningbo University,Ningbo 315000,Zhejiang,China
  • Received:2022-09-07 Revised:2023-04-20 Online:2024-03-30 Published:2024-04-24

Abstract:

Objective To analyze the clinical roles of rapid bacterial identification and drug susceptibility test of blood culture-positive samples by centrifuge enrichment method and 5 h culture method combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS). Methods Totally,211 blood culture-positive samples at the First Affiliated Hospital of Ningbo University from October 2021 to October 2022 were collected. The pretreatment was performed by centrifuge enrichment method and 5 h culture method(rapid method)and 12 h culture method(standard method),respectively. MALDI-TOF-MS was used for rapid isolate identification of blood culture-positive samples treated by the 3 methods. The drug susceptibility test of 156 blood culture-positive samples from aerobic bottle was carried out by automatic microbiological identification drug susceptibility instrument. According to the identification results of conventional culture(18-24 h)+MS,the identification accuracy of 2 rapid methods of 5 h culture method+MS and centrifuge enrichment method+MS were compared. According to the identification results of 24 h,the consistency of the results of drug susceptibility test between standard method after 5 h culture method,centrifuge enrichment was evaluated. Results The identification accuracy of Enterococcus faecalis was the highest,and the identification accuracies were 100.00% and 87.50%,respectively. The identification accuracy of Streptococcus was low(33.33%)after 5 h culture method+MS. The drug susceptibility test results of the 2 methods for Enterobacteriaceae and non-fermentative bacteria were more than 73.00% and 85.00%,respectively,compared with the results of standard method. The results of drug susceptibility test for Staphylococcus and Enterococcus were consistent(100.00%). The consistency of vancomycin sensitivity analysis was the lowest(70.73%). Conclusions The 5 h culture method+MS and centrifuge enrichment method+MS can rapidly identify the isolate and drug resistance of pathogenic bacteria in blood culture-positive samples with high accuracy,which is suitable for clinical microbiology laboratories.

Key words: Blood culture, Pathogen identification, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, Short-time culture method

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