Development of a multiple primer RAPD assay as a tool for phylogenetic analysis in Listeria spp. strains isolated from milkproduct associated epidemics, sporadic cases of listeriosis and dairy environments.
82 Listeria strains comprising 4 species were examined by amplification with a multiple primer random amplified polymorphic DNA (RAPD) assay. The objective was to establish a procedure for analysis of the relationships between strains from milk product-associated epidemics, from sporadic cases of listeriosis and from field strains. 205 primers, each 10-bp long were screened for suitability as primers and 44 primers showing reliable and reproducible RAPD patterns at a defined reaction condition were selected. The 82 strains were assigned to 54 RAPD groups positioned in 13 major clusters. Strains isolated during milk product-associated epidemics were among a single cluster. Human isolates from sporadic cases of listeriosis were assigned to 4 separate clusters and strains of clinical origin were assigned to different clusters from those of non-clinical origin.