title: [Isolation and identification of Cronobacter (Enterobacter sakazakii) strains from food].
abstract: OBJECTIVE
  This study aimed to detect and quantify Cronobacter in 300 powdered milk samples and 50 non-powdered milk samples. Totally, 24 Cronobacter (formerly Enterobacter sakazakii) strains isolated from powdered milk and other foods were identified and confirmed.
  
  
  METHODS
  Cronobacter strains were detected quantitatively using most probable number (MPN) method and molecular detection method. We identified 24 Cronobacter strains using biochemical patterns, including indole production and dulcitol, malonate, melezitose, turanose, and myo-Inositol utilization. Of the 24 strains, their 16S rRNA genes were sequenced, and constructed phylogenetic tree by N-J (Neighbour-Joining) with the 16S rRNA gene sequences of 17 identified Cronobacter strains and 10 non-Cronobacter strains.
  
  
  RESULTS
  Quantitative detection showed that Cronobacter strains were detected in 23 out of 350 samples yielding 6.6% detection rate. Twenty-four Cronobacter strains were isolated from 23 samples and the Cronobacter was more than 100 MPN/100g in 4 samples out of 23 samples. The 24 Cronobacter spp. isolates strains were identified and confirmed, including 19 Cronobacter sakazakii strains, 2 C. malonaticus strains, 2 C. dubliensis subsp. lactaridi strains, and 1 C. muytjensii strain.
  
  
  CONCLUSIONS
  The combination of molecular detection method and most probable number (MPN) method could be suitable for the detection of Cronobacter in powdered milk, with low rate of contamination and high demand of quantitative detection. 24 isolated strains were confirmed and identified by biochemical patterns and molecular technology, and C. sakazakii could be the dominant species. The problem of Cronobacter in powdered milk should be a hidden danger to nurseling, and should catch the government and consumer's attention.
authors: Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology (Ministry-Guangdong Province Jointly Breeding Base), Guangdong Provincial Key Laboratory of South China Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou 510070, China. dongxiaohuihebei@126.com
authors: Xiaohui
authors: X
authors: Dong
authors: Chengsi
authors: C
authors: Li
authors: Qingping
authors: Q
authors: Wu
authors: Jumei
authors: J
authors: Zhang
authors: Shuping
authors: S
authors: Mo
authors: Weipeng
authors: W
authors: Guo
authors: Xiaojuan
authors: X
authors: Yang
authors: Xiaoke
authors: X
authors: Xu
mesh_terms: D000818:Animals; D044083:Cronobacter sakazakii / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D005516:Food Microbiology; D006801:Humans; D008892:Milk / Q000382:microbiology; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S