Evaluation of increased incubation temperature and cefixime-tellurite treatment for the isolation of Escherichia coli O157:H7 from minced beef.
To improve enrichment and isolation of Escherichia coli O157:H7, this study evaluated increased incubation temperature and cefixime-tellurite (CT) on five strains of each of the following bacteria, E. coli, Hafnia alvei, Enterobacter spp., Citrobacter freundii and E. coli O157:H7, and two strains of E. coli O157:nH7. These were grown in pure culture in LST broth with varying cefixime-tellurite concentrations. A range of incubation temperatures from 37 to 46 degrees C was investigated for the inhibition of cohabitant microorganisms. Minced beef, spiked with E. coli O157:H7 and cohabitant microorganisms was investigated. Increased incubation temperature (42 degrees C) and treatment with half of the prescribed amount of cefixime-tellurite by BAM for SMAC agar in enrichment step were the most effective in selectively growing E. coli O157:H7. The results show that E. coli O157:H7 is more resistant to these two conditions than the other cohabitant bacteria.
Dogan
Hilal B
HB
Department of Food Engineering, Faculty of Agriculture, Ankara University, Diskapi, Ankara 06110, Turkey.
Kuleasan
Hakan
H
Cakir
Ibrahim
I
Halkman
A Kadir
AK
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D020682:Cefixime / Q000494:pharmacology; D016971:Citrobacter freundii / Q000254:growth & development / Q000302:isolation & purification; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D004754:Enterobacter / Q000254:growth & development / Q000302:isolation & purification; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification; D019453:Escherichia coli O157 / Q000254:growth & development / Q000302:isolation & purification*; D005516:Food Microbiology; D020611:Hafnia alvei / Q000254:growth & development / Q000302:isolation & purification; D008461:Meat Products / Q000382:microbiology*; D013691:Tellurium / Q000494:pharmacology; D013696:Temperature
D000900:Anti-Bacterial Agents; D020682:Cefixime; C026660:tellurous acid; D013691:Tellurium