ALEKSANDRA JANUSZKIEWICZ and WALDEMAR RASTAWICKI National Institute of Public Health – National Institute of Hygiene, Department of Bacteriology, Warsaw, Poland *Corresponding author: A. Januszkiewicz, National Institute of Public Health – National Institute of Hygiene, Warsaw, Poland; e-mail: ajanuszkiewicz@pzh.gov.pl. Submitted 3 December 2014, revised 28 July 2015, ...