Test results of Salmonella typing by the National Reference Laboratories for Salmonella in the Member States of the European Union and the EnterNet Laboratories - Collaborative study VII (2002) on typing of Salmonella

A seventh collaborative typing study forry for Salmonella (CRL-Salmonella, Bilthoven, The Netherlands) in collaboration with the Public Health Laboratory Services (PHLS), London, United Kingdom. Seventeen National Reference Laboratories for Salmonella (NRLs-Salmonella) and 15 EnterNet laboratories (ENLs) participated in the study. Three of the NRLs for Salmonella are also ENL. The results obtained by these three NRL-ENL laboratories will only be evaluated in conjunction with results of the 17 NRLs- Salmonella. In total, 20 strains of the species Salmonella enterica subspecies enterica were selected for serotyping while 10 strains of Salmonella Typhimurium (STM) and 10 strains of Salmonella Enteritidis (SE) were selected for phage typing. In general, no problems were encountered with the typing of the O antigens. However, some laboratories had problems with typing the H antigens. Almost all laboratories faced only minor differences in phage typing. Some ENLs had considerable problems with the phage typing of STM as well as SE strains. A questionnaire held among the NRLs revealed that for comparison between laboratories, standardisation of the antimicrobial susceptibility testing would have to be a requirement