Comparative evaluation of two methods of enumerating enterococci in foods: collaborative study.
Two methods of enumerating enterococci in foods were compared in a collaborative study. Thirteen laboratories tested four blind duplicate samples containing different levels of enterococci and two negative control samples. Freeze-dried mixtures of bacteria were used as simulated food samples. The freeze-dried samples were reconstituted and either spread directly on the surface of Slanetz and Bartley medium (SB) and incubated at 44 degrees C for 48 h or preincubated in tryptone soya agar at 37 degrees C for 2 h before being overlaid by SB and incubated at 37 degrees C for a further 46 h. The numbers CFU of enterococci recovered by the two methods were not significantly different except for one sample where the 37 degrees C method gave a somewhat higher recovery. The 44 degrees C method was less time-consuming and less laborious.
National Food Administration, Biology Division, Uppsala, Sweden.
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Peterz
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Steneryd
D000818:Animals; D015169:Colony Count, Microbial / Q000379:methods* / Q000592:standards; D003470:Culture Media; D016983:Enterococcus / Q000254:growth & development*; D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D005516:Food Microbiology; D006358:Hot Temperature; D008461:Meat Products / Q000382:microbiology*; D010376:Pediococcus / Q000254:growth & development; D015203:Reproducibility of Results; D013210:Staphylococcus / Q000254:growth & development
D003470:Culture Media