Integration of Chelex-100 thermal lysis and lyophilized LAMP for rapid point-of-care detection of surgical site infections following liver surgery.

BACKGROUND: Surgical site infection (SSI) is a serious and potentially lethal complication following liver surgery, which is commonly associated with nosocomial bacteria such as Klebsiella pneumoniae, Acinetobacter baumannii, Enterococcus faecalis, and Enterococcus faecium. To address the critical need for rapid on-site diagnosis of these infections in complex abdominal drainage fluid (ABDF), we developed the CTL-SSI-LAMP platform, a novel point-of-care system that uniquely integrates Chelex-100 thermal lysis (CTL) DNA extraction with lyophilized loop-mediated isothermal amplification (LAMP).

RESULTS: The optimized CTL method, which utilizes Chelex-100 resin to adsorb inhibitors and thermal treatment for efficient cell lysis, allowed for rapid DNA extraction from ABDF samples within 15 min using minimal equipment. Following optimization, the analytical sensitivity of the lyophilized SSI-LAMP assays was ≤ 103 CFU/mL with satisfactory analytical specificity, which was validated through both simulated and real ABDF samples. The entire detection process takes approximately 1 h to be completed without requiring specialized laboratory equipment. In a clinical cohort, the clinical sensitivity of our platform for these four SSI-related bacteria was 100%, while the clinical specificity was over 97%, with a negative predictive value of 100% and an overall accuracy exceeding 98%.

SIGNIFICANCE: The CTL-SSI-LAMP platform provides a rapid, portable, and culture-independent method for detecting major SSI-related bacteria directly from postoperative ABDF. By combining robust sample pretreatment with lyophilized reagents, this platform enables timely, targeted antimicrobial therapy and is highly suitable for point-of-care application in intensive care units, operating rooms, and resource-limited clinical settings.