The Phenotypic and Genotypic Characterization of Korean Isolates of Cronobacter spp. (Enterobacter sakazakii)

Abstract

This study was conducted to investigate the phenotypic and genotypic characteristics of Korean isolates of Cronobacter spp. (Enterobacter sakazakii). A total of 43 Cronobacter spp., including 5 clinical isolates, 34 food isolates, 2 environmental isolates, and 2 reference strains (C. sakazakii ATCC 29004 and C. muytjensii ATCC51329) were used in this study. Korean isolates of Cronobacter spp. were divided into 11 biogroups according to their biochemical profiles and 3 genomic groups based on the analysis of their 16S rRNA gene sequences. Biogroups 1 and 2 contained the majority of isolates (n=26), most of which were contained in 16S rRNA cluster 1 (n=34). Korean isolates of Cronobacter spp. showed diverse biochemical profiles. Biogroup 1 contained C. sakazakii GIHE (Gyeonggido Research Institute of Health and Environment) 1 and 2, which were isolated from babies that exhibited symptoms of Cronobacter spp. infection such as gastroenteritis, sepsis, and meningitis. Our finding revealed that Biogroup 1, C. sakazakii, is more prevalent and may be a more pathogenic biogroup than other biogroups, but the pathogenic biogroup was not represented clearly among the 11 biogroups tested in this study. Thus, all biogroups of Cronobacter spp. were recognized as pathogenic bacteria, and the absence of Cronobacter spp. in infant foods should be constantly regulated to prevent food poisoning and infection caused by Cronobacter spp.

Occurrence and Characterization of Cronobacter spp. in Dehydrated Rice Powder from Chinese Supermarket

“…sakazakii and C . malonaticus to be the most common species (66/76), similar to results of other studies [ 37 – 38 ]. And the two species most commonly associated with human disease [ 13 ].…”

The Genotypic Characterization of Cronobacter spp. Isolated in China

“…Here the isolates' species identification was determined by fusA allele sequence typing based on Joseph's study. Similar to other studies [22], [23], C. sakazakii was isolated from all sources, and was the most common Cronobacter species. Except for four isolates from food sources, the other 12 isolates, which were classified as C. dublinensis or C. turicensis , were from environment.…”

Surveillance and molecular typing of Cronobacter spp. in commercial powdered infant formula and follow‐up formula from 2011 to 2013 in Shandong Province, China

“…can also pose potential health hazards. 20,21 In the present study, Cronobacter spp. were isolated from both PIF and FUF, and C. sakazakii was the most common Cronobacter spp.…”

“…In addition, because FUF is one of the major food sources for infants, contamination of FUF with Cronobacter spp. can also pose potential health hazards …”