Microorganisms colonising historical cardboard objects from the Auschwitz-Birkenau State Museum in Oswiecim, Poland and their disinfection with vaporised hydrogen peroxide (VHP)

In the Auschwitz-Birkenau State Museum in Oswiecim, Poland (A-BSM) a new research has been started on the use of vaporised hydrogen peroxide (VHP) as a disinfecting agent. The aims of the study were: to identify microorganisms inhabiting historical cardboard using molecular methods (MALDI-TOF MS, 16S rRNA genes sequencing and next-generation sequencing on Illumna platform); to establish the effectiveness of VHP disinfection (300 ppm, 20 min); and to evaluate the impact of VHP and ethylene oxide (EtO) on the physico-chemical properties of the new and historical cardboard (spectrophotometrical colour measurements, SEM, FTIR and XPS), including changes after accelerated ageing. On the surfaces of the historical objects containing cardboard 10(4)-10(5) CFU/100 cm(2) of bacteria and approximately 10(3) CFU/100 cm(2) of fungi were detected. The predominant were: Bacillus licheniformis, Bacillus megaterium, Micrococcus luteus, Staphylococcus epidermidis, Alternaria alternata, Cladosporium cladosporioides and Penicillium chrysogenum. VHP disinfection under the conditions of performed tests resulted in a reduction of 99.61-100.00% for bacteria and 98.82-100.00% for fungi. The surface morphology, cellulose structure, chemical composition and perceptible to the naked eye colour of the new and historical cardboard were not changed after application of VHP in a tested dose and following EtO disinfection.