Prevalence of Salmonella Infantis (S.I.) in the Hungarian broiler flocks has increased three times higher than the average prevalence in the EU. The human prevalence of S.I. has also increased in Hungary. The aim of these studies is to find an explanation for this increase, on the basis of genetic and pathogenetic attributes of the new emerging strains.
OTKA K 101546
Due to the Salmonella reduction program in Hungary, the prevalence of the two most important serovars of Salmonella (S. Enteritidis and S. Typhimurium) has greatly decreased. However, the prevalence of mutidrug resistant S. Infantis has increased a great deal. In search for a molecular epidemiological and genomic explanation for this phenomenon the main hypothesis is that these strains might have arrived to Hungary with imported breeder chicks. The research aim is to perform comparative genomic and molecular epidemiologic studies on pre-emergent S.I. strains of the last 10-15 years from the Hungarian and foreign broiler flocks and to search for evolutionary evidences by genome manipulations and comparative genome analyses. The preliminary results of research, involving in vitro and in vivo pathogenetic studies, as well as deletion of plasmids and pathogenicity islands (SPIs) are indicating that the basic virulence armory of the pre-emergent and and emerging S.I., as well as of the foreign and Hungarian S.I. are basically very similar but some clones might have better utilized the advantages of horizontal gene stransfer (ie. of MDR plasmids). Thus, such clones could have gained selective advantages.
Olasz, Ferenc senior researcher, director; Kiss, János, researcher; Szabó, Mónika researcher; Wilk, Tímea research associate; Nagy, Tibor researcher (all in NAIK, Agricultural Biotechnology Institute, Gödöllő, Hungary)
Pászti, Judit researcher, head of main-department (ANTSz, National Center for Epidemiology, Gödöllő, Hungary)
Emődy, Levente senior researcher (PTE, AOK, Institute for Medical Microbiology and Immunology, Pécs, Hungary)
Nógrády, Noémi researcher; Imre, Ariel researcher (CEVA-Phylaxia, Budapest, Hungary)