Preliminary screening of Salmonella in oral drugs by visual LAMP technology

Objective According to the Chinese Pharmacopoeia, Salmonella should not be detected in oral drugs. In this experiment, LAMP technology was used to detect Salmonella quickly, and the detection results were visible to the naked eye with calcein-Mn 2+ dye, so as to provide pharmaceutical companies with the initial screening of drugs containing Salmonella . Methods Four primers (FIP, BiP, F3, B3) were designed to detect Salmonella by loop mediated isothermal amplification using inv A gene of Salmonella , and then the loop mediated isothermal amplification detection method was established. To verify the specificity of the method, LAMP detection was carried out on 10 kinds of laboratory preserved strains. The sensitivity of the method was obtained by detecting 10 times gradient dilution of Salmonella bacteria solution. Finally, the LAMP system of Salmonella was used to detect the oral drugs sold on the market and not tested by the Drug Administration, and the sensitivity of the system in the drug was determined. Based on these methods, Calcein-Mn 2+ dye was added to test the availability of the dye. Results After optimization, the specificity of the system was good. For 10 different strains of LAMP detection, only Salmonella appeared trapezoidal band, and other strains did not detect the band; Through the experimental verification, the sensitivity of the system was 3.2 × 10 1 CFU/mL; The system was used for the oral drugs sold in the market and not passed the inspection of the drug administration The results of LAMP detection showed that no Salmonella was detected. However, the results of LAMP detection showed that there were trapezoidal bands in the test results. The sensitivity of the system in the detection of Salmonella in oral drugs could reach 3.8 × 10 1 CFU/mL. Adding calcein-Mn 2+ dye into the system, the presence or absence of Salmonella can be distinguished by naked eye observation, and the detection limit is about 10 2 CFU/mL. Conclusion The visual LAMP detection system for Salmonella can be used for the preliminary screening of oral drugs containing Salmonella .