Contamination status, molecular typing and antimicrobial resistance of Cronobacter spp. in dormitory and canteen

Objective To investigate the contamination status, molecular typing and antimicrobial resistance characteristics of Cronobacter spp. in dormitory and canteen of a school in Xuzhou, and to provide reference data for earlywarning of foodborne disease outbreak caused by Cronobacter spp. . Methods A total of 156 environmental samples were collected from the dormitory and canteen of a school in Xuzhou, and Cronobacter strains were isolated and identified. The O-antigen-based serotyping and multilocus sequence typing were applied for molecular typing of the Cronobacter strains, and the antimicrobial resistance of Cronobacter strains were determined by disk diffusion method. Results Eleven(7.1%) of 156 environmental samples were positive for Cronobacter spp. , with the detection rate of 6.6%(8/121) and 8.6%(3/35) in dormitories and canteens, respectively. Based on the fusA sequence analysis, 8 of 11 isolates were identified as C. sakazakii, whereas the other 3 were identified as C. malonaticus. The 11 Cronobacter strains were assigned to 5 sequence types, and ST500 was the predominant sequence type(54. 5%, 6/11). Meanwhile, the 11 Cronobacter strains were divided into 5 serotypes, with C. sakazakii serotype O7(Csak O7) being the predominant serotype(54.5%, 6/11). The antimicrobial resistance test indicated that all isolates were sensitive to cefixime, amikacin, ciprofloxacin, furantoin, chloramphenicol and ticarcillin/clavulanic acid, whereas strains resistant to cefthiophene(63. 6%, 7/11) and meropenem(27.3%, 3/11) were founded. Conclusion There is a risk of contamination of Cronobacter spp. in the environment of student dormitory and canteen. The epidemiological surveillance of Cronobacter spp. in the dormitory and canteen environment should be strengthened in future.