OBJECTIVE  Based on accurate identification, this study conducted a comparative study on the accuracy of antimicrobial susceptibility testing for blood culture-positive specimens through three methods: the traditional method, the direct method and the bacterial film method. This aims to explore the value of different treatment approaches for management of patients with bloodstream infections （BSI）, thereby providing a basis for the rational clinical use of antimicrobial agents.

METHODS  We randomly collected a total of 55 blood culture-positive specimens at the main campus of Qingdao Municipal Hospital from Jan. 2025 to Jun. 2025. Drug susceptibility testing was performed through the traditional method, the direct method and the bacterial film method to assess the consistency of the results among the three methods. Additionally, basic information from 99 and 73 patients with blood culture-positive specimens was collected separately as data for the traditional method and the biofilm method, comparing the length of hospital stay, outcomes and prognosis between the pre-optimization traditional method and post-optimization bacterial form method.

RESULTS  In terms of drug susceptibility, compared to the traditional method, for gram-positive bacteria, the overall categorical agreement （CA%） for Staphylococcus aureus was 98.33% with the bacterial film method and 91.67% with the direct method. For Enterococcus, it was 100.00% with the bacterial film method and 97.14% with the direct method. For coagulase-negative Staphylococcus, it was 100.00% with the bacterial film method and 95.00% with the direct method. For gram-negative Enterobacteriaceae, the overall CA% for Klebsiella pneumoniae was 98.69% with the bacterial film method and 96.73% with the direct method. For Escherichia coli, it was 95.61% with the bacterial film method and 97.37% with the direct method. For other Enterobacteriaceae, it was 98.96% with the bacterial film method and 94.79% with the direct method. For gram-negative non-fermentative bacteria, the overall CA% for Pseudomonas aeruginosa was 98.03% with the bacterial film method and 96.15% with the direct method. For Acinetobacter baumannii, it was 95.79% with the bacterial film method and 97.89% with the direct method. In terms of clinical outcomes and prognosis, compared to the traditional method, patients in intensive care units （ICU） treated with the bacterial film method were old on average, but had a short average length of hospital stay and a high survival rate （P＜0.001）.

CONCLUSIONS  Compared with the traditional method, the direct method and bacterial film method for drug susceptibility testing exhibits high classification consistency and low error rates. Moreover, utilizing the bacterial film method to determine drug susceptibility in positive patients can reduce the length of hospital stay and improve patient survival rates.