DVG Fachgruppe: Parasitologie und Parasitäre Krankheiten

§Objective: Characterisation of the resistance (R) phenotypes and underlying molecular mechanisms present in European strains positive for "Salmonella Genomic Island 1" (SGI1) collected within WP21. To look for selected virulence genes following the guidelines set by the "Virulotyping project" (WP26) in these Salmonella strains. §Methods: Thirty-one Salmonella strains (11 S. non-Typhimurium and 20 Typhimurium), isolated between 2002 and 2006 in six European countries, that had been tested positive for SGI-1 at HPA in 2006, were sent to the BfR. All isolates were tested for their susceptibility to 17 antimicrobial agents by MHK according to CLSI and were screened by PCR for class 1 integrons as well as 30 R-genes. In addition plasmid analysis and MLVA were carried out. Virulotyping aimed at 10 virulence genes. §Results: All isolates harboured class 1 integrons with a variable region of different sizes. Following resistance genes were detected so far: ampicillin ( bla PSE , bla TEM-1 ), chloramphenicol ( floR, cat , cmlA ), streptomycin ( aadA1-like, strA ), sulfonamides ( sul1 ), tetracycline [ tet (G), tet(A)], trimethoprim ( dfrA1 , dfrA14 , dfrA12 , dfrA7-17 ), fluoroquinolones ( qnrB ). Five of the virulence genes ( ssaQ , mgtC , spi4_D , sopB, bcfC ) were present in all the isolates tested. In the majority of strains plasmids were present (15 different patterns). By MLVA Analysis, the S. Typhimurium strains were ascribed to 19 types. §Conclusion: We are setting up a well characterised strain collection that can be used as control for several molecular approaches. Furthermore the link to other workpackages (WP26) should provide a solid basis for future European cooperation on resistance/virulence testing and risk assessment.