title: Dry and moist heat sterilisation cannot inactivate pyrogenicity of Gram positive microorganisms.
abstract: In the monocytic cell line Mono Mac 6 pyrogens induce interleukin-6 secretion dose dependently. The aim of this study is to examine the interleukin-6 inducing capacity of Gram positive Staphylococcus aureus and Bacillus subtilis endospores after moist and dry heat sterilisation. Moist heat sterilisation of B. subtilis endospores for 15 min at 121 degrees C and 134 degrees C can only reduce the interleukin-6 inducing capacity to 57% and 63%, respectively, compared to untreated. Moist heat sterilisation of S. aureus for 60 min at 121 degrees C and 134 degrees C does not reduce the interleukin-6 inducing capacity of S. aureus. On the contrary moist heat sterilisation at 134 degrees C for 10, 20 and 40 min significantly increases the interleukin-6 inducing capacity compared to untreated S. aureus. This is confirmed in the rabbit pyrogen test. Dry heat sterilisation of B. subtilis endospores at 220 degrees C for 45 min reduces the interleukin-6 inducing capacity to 2% compared to untreated endospores. Dry heat treatment of S. aureus at 220 degrees C for 30 min only reduces the activity to 55%. However, after 250 degrees C for 30 min or 220 degrees C for 6h there is no detectable activity of S. aureus. In conclusion, neither the interleukin-6 inducing activity nor the pyrogenicity of S. aureus and endospores of B. subtilis can be inactivated by the heat sterilisation procedures described by the European Pharmacopoeia.
authors.affiliation: The Danish University of Pharmaceutical Sciences, Department of Pharmacology, 2 Universitetsparken, DK-2100 Copenhagen, Denmark. LM@dfuni.dk
authors.forename: Lise
authors.initials: L
authors.lastname: Moesby
authors.forename: Erik W
authors.initials: EW
authors.lastname: Hansen
authors.forename: Jens D
authors.initials: JD
authors.lastname: Christensen
authors.forename: Catrine H
authors.initials: CH
authors.lastname: Høyer
authors.forename: Gitte L
authors.initials: GL
authors.lastname: Juhl
authors.forename: Helle B
authors.initials: HB
authors.lastname: Olsen
mesh_terms: D000818:Animals; D006094:Gram-Positive Bacteria / Q000472:pathogenicity*; D006358:Hot Temperature; D006801:Humans; D011749:Pyrogens; D011817:Rabbits; D013242:Sterilization / Q000379:methods*
chemical_list: D011749:Pyrogens