HEAT TOLERANCE OF VANCOMYCIN-RESISTANT ENTEROCOCCUS-FAECIUM

The heat tolerance of 27 Enterococcus faecium isolates in water was st udied. Stationary phase cultures including vancomycin resistant and se nsitive clinical and food isolates were exposed to heat at 60 degrees, 65 degrees, 71 degrees, and 80 degrees C for one, three, 10, and 30 m inutes and the log(10) reductions in bacterial counts were determined. Exposure at 71 degrees and 80 degrees C resulted in >6 log(10) reduct ion in viable counts for all isolates. Seven (24%) isolates survived ( <5 log(10) reduction) heat at 65 degrees C for 10 minutes. The E faeci um isolates were more resistant to heat than the two E faecalis refere nce strains. No differences in heat tolerance were observed between va ncomycin sensitive and resistant strains or between isolates of human or food origin.