Genomic insights into Cronobacter spp. recovered from food and human clinical cases in Zhejiang province, China (2008-2021).

Abstract

Cronobacter spp. are emerging food-borne pathogens capable of causing life-threatening illness via several distinct routes. Although endeavors to reduce the incidence of Cronobacter infections are implemented, potential risk of these microorganisms on food safety remains poorly understood. Here, we evaluated the genomic features of clinical Cronobacter and the possible food reservoirs of these infections. Whole-genome sequencing (WGS) data of all human clinical cases (n=15) during 2008-2021 in Zhejiang were used and compared to sequenced Cronobacter genomes (n=76) representing various food products. Cronobacter strains exhibited a high degree of genetic diversity by WGS-based subtyping. A variety of serotypes (n=12) and sequence types (n=36) were identified, including six novel STs (ST762-ST765, ST798, and ST803) first-time described in this study. Nine clinical clusters representing 12/15 (80%) patients match a potential food source. Genomic insights into virulence genes revealed species/hosts specificity signatures associated with autochthonous populations. Resistance to streptomycin, azithromycin, sulfanilamide isoxazole, cefoxitin, amoxicillin, ampicillin, and chloramphenicol, as well as multidrug resistance, was noted. WGS data can be used to predict resistance phenotypes in amoxicillin, ampicillin, and chloramphenicol, which were extensively used in clinical treatment. The wide dissemination of pathogenic potential and antibiotic-resistant strains in multiple food sources emphasized the importance of rigorous food safety policies to reduce Cronobacter contamination in China.