Isolation and characterization of Cronobacter from desiccated foods in Korea

A total of 115 desiccated food samples, including agricultural and marine products, were investigated for the presence of Cronobacter. Cronobacter species were characterized with biochemical tests. Antibiotic resistance was assessed with the disk diffusion method, and the molecular subtypes of Cronobacter isolates were identified using an automated repetitive sequence-based PCR (rep-PCR) system. A total of 18 (15.7%) Cronobacter strains were isolated from 115 desiccated food products. Fifteen Cronobacter isolates were C. sakazakii (13%), followed by 2 C. dublinensis (1.7%), and 1 C. universalis (0.9%). The most common antibiotic resistance of Cronobacter observed was against cephalothin (77.8%) followed by ampicillin (5.6%). With exception of 2 strains, all Cronobacter strains isolated from different sources were successfully differentiated by using the automated rep-PCR system, indicating that it can be used for the purpose of contamination or outbreak source tracking of the bacteria.