カルバペネム耐性腸内細菌科細菌（CRE）におけるカルバペネマーゼ遺伝子の迅速かつ高感度な検出のためのループメディエイトアイソサーマル増幅（LAMP）：診断的検証研究

To evaluate the clinical utility of loop-mediated isothermal amplification (LAMP) for detecting carbapenemase genes in carbapenem-resistant Enterobacteriaceae (CRE).

From January 2023 to December 2024, 112 clinical CRE isolates were collected, including 104 carbapenem-resistant Klebsiella pneumoniae (CR-KP), 7 Escherichia coli (CR-EC), and 1 Klebsiella oxytoca (CR-KO). These isolates were obtained primarily from sputum (n=65), urine (n=29), and bronchoalveolar lavage fluid (n=9). The isolates were predominantly isolated from neurosurgery (38.39%), intensive care unit (21.42%), and respiratory critical care medicine (15.18%). Carbapenemase genes were detected in parallel using both sequencing (reference standard) and LAMP methods under blinded conditions. Statistical analysis included cross-tabulation and Cohen's kappa coefficient for agreement assessment.

Among the 112 CRE isolates, 96.43% (108/112) carried carbapenemase resistance genes. KPC variants predominated (89/108, 82.4%), including blaKPC-2 (n=87) and blaKPC-33 (n=2). NDM variants were detected in 29 isolates (26.9%), comprising blaNDM-1 (n=14) and blaNDM-5 (n=15). OXA-48 was identified in 3 isolates (2.8%). Compared with sequencing, LAMP demonstrated perfect sensitivity (100%) for all three gene types, with specificities of 91.30% (KPC), 96.38% (NDM), and 100% (OXA-48). However, the performance data for OXA-48 should be considered preliminary due to the low number of positive isolates (n=3).The kappa values indicated excellent agreement: 0.943 (KPC), 0.932 (NDM), and 1.000 (OXA-48).

LAMP technology shows high diagnostic accuracy for detecting major carbapenemase genes particularly KPC and NDM in CRE isolates, offering a reliable tool for guiding appropriate antibiotic therapy. Its operational simplicity and cost-effectiveness make it particularly suitable for implementation in primary healthcare settings.