Molecular Surveillance of Cronobacter spp. Isolated from a Wide Variety of Foods from 44 Different Countries by Sequence Typing of 16S rRNA, rpoB and O-Antigen Genes.

Nancy Miranda,Khalil Kerdahi,Irshad Sulaiman,Steven Simpson,Pratik Banerjee

doi:10.3390/foods6050036

Abstract

Cronobacter spp. are emerging infectious bacteria that can cause acute meningitis and necrotizing enterocolitis in neonatal and immunocompromised individuals. Although this opportunistic human-pathogenic microorganism has been isolated from a wide variety of food and environmental samples, it has been primarily linked to foodborne outbreaks associated with powdered infant formula. The U.S. Food and Drug Administration use the presence of these microbes as one of the criteria to assess food adulteration and to implement regulatory actions. In this study, we have examined 195 aliquots of enrichments from the nine major categories of foods (including baby and medical food, dairy products, dried food, frozen food, pet food, produce, ready-to-eat snacks, seafood, and spices) from 44 countries using conventional microbiological and molecular techniques. The typical colonies of Cronobacter were then identified by VITEK2 and real-time PCR. Subsequently, sequence typing was performed on the 51 recovered Cronobacter isolates at the 16S rRNA, rpoB and seven O-antigen loci for species identification in order to accomplish an effective surveillance program for the control and prevention of foodborne illnesses.

Highlights

Cronobacter spp. is a group of Gram-negative bacteria belonging to the family Enterobacteriacea which can survive in environments with extremely dry conditions
All 195 food samples were initially tested for the presence of Salmonella, Listeria monocytogenes, and E. coli as part of an ongoing surveillance program for food safety of the agency
There were 14 food samples that tested positive for these three bacterial species known to cause foodborne diseases; Salmonella was detected in half of the 14 food samples tested

Summary

Introduction

Cronobacter spp. is a group of Gram-negative bacteria belonging to the family Enterobacteriacea which can survive in environments with extremely dry conditions It is considered an emerging opportunistic pathogen capable of causing severe infections including necrotizing enterocolitis, bacteremia, and meningitis in humans [1,2,3]. This multi-species complex is typically facultative anaerobic, oxidase-negative, catalase-positive, rod-shaped, motile, non-spore forming bacteria that can predominantly produce a yellow pigment. Even though seven species of Cronobacter have been described (including C. sakazakii, C. muytjensii, C. turicensis, C. dublinensis, C. malonaticus, C. universalis, and C. condimenti), only three of these species A very wide temperature range (6 to −45 ◦ C) has been reported for the typical growth of this group in brain heart infusion broth [4]

Methods

Results

Discussion

Conclusion