[1] Univ Turku, Ctr Biotechnol, FIN-20521 Turku, Finland
[2] Abo Akad Univ, FIN-20521 Turku, Finland
[3] Univ Turku, Dept Biol, FIN-20014 Turku, Finland
[4] Univ Turku, Med Res Lab, FIN-20520 Turku, Finland
[5] Univ Turku, Dept Med Microbiol, FIN-20520 Turku, Finland
[6] Natl Publ Hlth Inst, FIN-20520 Turku, Finland