Resistance of enterococci to heat and chemical agents

Within the framework of the standardisation efforts on disinfectant testing on the European level the test germ Enterococcus hirae ATCC 10541 has been included for some time in the test requirements whereas the test strain En terococcus faecium, which has frequently been used up to now, has been larg ely ignored. We compared the thermal and the chemical resistance of both test germ speci es. In the quantitative suspension test with active ingredients from the gr oup of aldehydes, phenols, quaternaries and oxidizing agents with the excep tion of peracetic acid, no significant differences were determined between the two strains. In the case of the stud ies on thermal resistance at 65 de grees C and 68 degrees C, Enterococcus faecium ATCC 6057, by contrast, prov ed to be far more resistant than Enterococcus hirae ATCC 10541. According to these results, priority should be given to Enterococcus faeciu m over Enterococcus hirae as the test germ for chemical and also chemotherm al disinfection.