[Contamination and pathogenicity analysis of listeria monocytogenes in restaurant in Heilongjiang Province].

Objective: To study the contamination, serotype, pulsed field gel electrophoresis (PFGE) and drug resistance of listeria monocytogenes (L.monocytogenes) in the process of restaurant kitchens in Heilongjiang Province. Methods: Seventeen typical restaurants were selected from three cities in Heilongjiang Province in 2016, and 590 kitchen samples were collected and tested according to the national standard method. The serotype, pulsed field gel electrophoresis (PFGE) and drug resistance of isolated strains were analyzed. Results: L. monocytogenes was found in 104 of 590 of the samples analysed (17.63%). The isolates belong to six serotypes (1/2 a, 1/2 b, 1/2c, 3a, 3 b, 4 b) and self-condensing bacteria, and 57.38% (70 strains) of the strains belong to serotype 1/2b. Two highly pathogenic serotype 4b was detected for human listeria disease. The results of PFGE analysis show that the bacteria have cross-contamination in the environment, tools, equipment, food and personnel. The drug resistance results showed that 2 strains were resistant to tetracycline, 1 strain was resistant to erythromycin, 13 strains were intermediate to tetracycline, and 2 strains were resistant to tetracycline and erythromycin. Conclusion: There is a certain degree of L. monocytogenes cross-contamination in the catering kitchen in Heilongjiang Province. And an important serotype 4b that can cause human Listeria disease was detected.