Evaluation of a novel and rapid screening method for the detection of contaminated colistin-resistant bacteria in food

Abstract Background: The dissemination of colistin-resistant bacteria carrying the colistin-resistant mobile gene, mcr-1 threatens medical care worldwide. In particular, contamination of food with colistin-resistant bacteria accelerates the community dissemination of colistin-resistant bacteria. Therefore, monitoring of colistin-resistant bacteria in food is important for controlling resistant bacteria. Unfortunately, the conventional culture methods for detecting colistin-resistant bacteria are not practical for monitoring food saftey. Therefore, development of a simple and rapid method to detect food contamination with colistin-resistant bacteria is desirable as an effective means for preventing the dissemination of resistant bacteria, particularly colistin-resistant bacteria.Findings: We developed a simple and rapid method for detecting Escherichia coli harboring the mcr-1 colistin resistance gene using a high-speed real-time polymerase chain reaction (PCR). The entire procedure, from sample processing to finals results, was performed within one hour. The practical utility of this method was verified by analyzing 27 retail meat samples for the presence of colistin-resistant bacteria. The results of the developed method were in agreement with the results of culturing colistin-resistant E. coli from the meat samples, demonstrating its efficacy and usefulness.Conclusions: A simple and rapid real-time PCR-based screening method was developed for detecting E. coli harboring mcr-1 in food samples. The practical utility of the procedure was confirmed using retail meat samples, indicating its potential as a convenient and rapid method to detect bacterial contamination of food items, especially in developing communities.