An effective, rapid and simple method for isolation of Shiga toxin-producing Escherichia coli O26, O111 and O157 from faeces and food samples.
An effective, rapid and simple method was developed for isolating Shiga toxin-producing Escherichia coli (STEC) O26:H11, O111:H- and O157:H7 from faeces and food in less than 24 h. The procedure involves enrichment of these samples in Trypticase soy broth (TSB) at 42 degrees C for 6 h. The enrichment culture is exposed to 1/8N HCl +0.5% NaCl solution (1 + 1) for 30 sec, then plated onto MacConkey agar containing sorbitol, tellurite and cefixime (CT-SMAC) following culture at 37 degrees C for 18 h. The findings were compared with conventional enrichment methods for efficiency in recovering STEC from bovine faeces. The new method increased the sensitivity for isolation of < 10(2) STEC O26:H11, O111:HUT and O157:H7 CFU/g of bovine faeces and decreased the growth of other gram-negative microorganisms. This procedure is readily implemented for use in laboratories doing routine microbiological testing.
Fukushima
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Public Health Institute of Shimane Prefecture, Shimane, Japan. hiroshi@joho-shimane.or.jp
Gomyoda
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D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism; D002417:Cattle; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D019453:Escherichia coli O157; D005243:Feces / Q000382:microbiology*; D005516:Food Microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology; D022603:Shiga Toxins; D013696:Temperature; D013997:Time Factors
D001427:Bacterial Toxins; D003470:Culture Media; D022603:Shiga Toxins