The Identification, Antibiotic Resistance, Virulence Characteristics, and Genome Analysis of <i>Cronobacter</i> spp. Isolated from Infant Rice Cereal in Nanchang, China

<i>Cronobacter</i> spp. are well known to be resistant to osmotic and dry stresses and can persist in a variety of foods. <i>C. sakazakii</i> and <i>C. malonaticus</i> are currently considered to be the primary pathogenic species that cause severe diseases. There are few studies on the prevalence of <i>Cronobacter</i> spp. in infant rice cereal. Information on the diversity, pathogenicity, and virulence of <i>Cronobacter</i> species obtained from foods is still relatively scarce and fragmentary. In this article, a total of 67 <i>Cronobacter</i> spp. strains were isolated from infant rice cereal in Nanchang, China. Forty-seven strains of <i>C. sakazakii</i> and 11 strains of <i>C. malonaticus</i> were identified by polymerase chain reaction (PCR). The resistance to 10 antibiotics was analyzed, showing that all isolates were sensitive except two strains. PCR detection for the five virulence genes (<i>cpa</i>, <i>aut</i>, <i>hly</i>, <i>inv</i>, and <i>sip</i>) and whole genome sequencing were performed. Co-existence of CSA or CMA with <i>ampH</i> was found in <i>C. sakazakii</i> and <i>C. malonaticus</i> strains. Compared with <i>C. sakazakii</i>, <i>C. malonaticus</i> lacked various virulence genes including <i>yeeJ</i>, <i>stjC</i>, and <i>nanAKT</i> genes. Another important observation was the presence of <i>csg</i> in the <i>C. malonaticus</i> genomes, while it was not found in the <i>C. sakazakii.</i> Notably, STs 1, 7, and 4, which are frequently associated with clinical infections, were observed. <i>C. sakazakii</i> and <i>C. malonaticus</i> strains induced higher apoptosis rate in Caco-2 cell in comparison with other <i>Cronobacter</i> species.