Prevalence and genetic diversity of Enterobacter sakazakii in ingredients of infant foods.
Various food samples in Korea were examined for the presence of Enterobacter sakazakii. Dried shrimp had the highest contamination rate among the examined dried fish products. E. sakazakii isolates were confirmed using an API 20E kit and a polymerase chain reaction (PCR) targeting the rDNA operons. The isolates were subtyped by pulsed-field gel electrophoresis (PFGE) using XbaI to elucidate the genetic diversity of the organisms. Ten pulsotypes were identified using PFGE and 22 types were identified from the random amplified polymorphism DNA (RAPD) assay. An antibiotic resistance test was performed by disk diffusion assay using eight antibiotics: nalidixic acid, ciprofloxacin, chloramphenicol, ampicillin, tetracycline, gentamicin, kanamycin, and cephalothin. Most of the E. sakazakii isolates were resistant to ampicillin or cephalothin but susceptible to the other antibiotics. The analysis of E. sakazakii isolates using PFGE, RAPD, and the antibiotic resistance test identified 18 composite types from 113 isolates, suggesting diverse sources of contamination.
Kim
Kyumson
K
Department of Food and Animal Biotechnology, School of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea.
Jang
Sung Sik
SS
Kim
Sung Ki
SK
Park
Jong-Hyun
JH
Heu
Sunggi
S
Ryu
Sangryeol
S
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D044083:Cronobacter sakazakii / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005506:Food Contamination / Q000032:analysis*; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D019105:Random Amplified Polymorphic DNA Technique; D017747:Seafood / Q000382:microbiology; D012758:Shellfish / Q000382:microbiology
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial