Molecular typing of staphylococcal communities isolated during municipal solid waste composting process

Abstract

This study investigates the molecular typing occurrence of staphylococcal communities during composting process of municipal solid waste. One hundred staphylococcal strains were isolated during the composting process and analysed either by phenotypic and genotypic methods. Amplified ribosomal DNA restriction analysis (ARDRA), internal transcripted spacer-polymerase chain reaction (ITS-PCR) and pulsed-field gel electrophoresis (PFGE) were used as molecular tools. During the digestion phase of composting process three staphylococcal species were recovered: Staphylococcus xylosus (48%), Staphylococcus lentus (40%), and Staphylococcus hominis (12%). In the maturation phase in addition to the latter species four species were also recovered at low frequencies: Staphylococcus lugdunensis, Staphylococcus haemolyticus, Staphylococcus warneri and Staphylococcus sciuri. Therefore, the composition of staphylococcal communities was temperature-, and phase dependant. The molecular methods showed that the ARDRA was not able to differentiate between strains of the same species. However, the ITS-PCR and the PFGE methods allowed interspecies and intraspecies discrimination, respectively.