Diversity of Cronobacter spp. isolates from the vegetables in the middle-east coastline of China.
Cronobacter spp. has caused life-threatening neonatal infections mainly resulted from consumption of contaminated powdered infant formula. A total of 102 vegetable samples from retail markets were evaluated for the presence of Cronobacter spp. Thirty-five presumptive Cronobacter isolates were isolated and identified using API 20E and 16S rDNA sequencing analyses. All isolates and type strains were characterized using enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR), and genetic profiles of cluster analysis from this molecular typing test clearly showed that there were differences among isolates from different vegetables. A polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) based on the amplification of the gyrB gene (1258 bp) was developed to differentiate among Cronobacter species. A new PCR-RFLP assay based on the amplification of the gyrB gene using Alu I and Hinf I endonuclease combination is established and it has been confirmed an accurate and rapid subtyping method to differentiate Cronobacter species. Sequence analysis of the gyrB gene was proven to be suitable for the phylogenetic analysis of the Cronobacter strains, which has much better resolution based on SNPs in the identification of Cronobacter species specificity than PCR-RFLP and ERIC-PCR. Our study further confirmed that vegetables are one of the most common habitats or sources of Cronobacter spp. contamination in the middle-east coastline of China.
State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Research Center of Dairy Biotechnology, Dairy Research Institute, Bright Dairy and Food Co., Ltd., Synergetic Innovation Center of Food Safety and Nutrition, 1518 West Jiangchang Rd., Shanghai, 200436, China.
Wanyi
W
Chen
Shanghai Entry-Exit Inspection and Quarantine Bureau, 1208 Minsheng Rd., Shanghai, 200135, China.
Jielin
J
Yang
State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Research Center of Dairy Biotechnology, Dairy Research Institute, Bright Dairy and Food Co., Ltd., Synergetic Innovation Center of Food Safety and Nutrition, 1518 West Jiangchang Rd., Shanghai, 200436, China.
Chunping
C
You
State Key Laboratory of Dairy Biotechnology, Shanghai Engineering Research Center of Dairy Biotechnology, Dairy Research Institute, Bright Dairy and Food Co., Ltd., Synergetic Innovation Center of Food Safety and Nutrition, 1518 West Jiangchang Rd., Shanghai, 200436, China. liuzhenmin@brightdairy.com.
Zhenmin
Z
Liu
D015373:Bacterial Typing Techniques; D002681:China; D016000:Cluster Analysis; D059126:Cronobacter / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000235:genetics; D005516:Food Microbiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014675:Vegetables / Q000382:microbiology*
D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
Cronobacter spp.; Identify; Isolate; PCR–RFLP; gyrB