MOLECULAR SUBTYPING SCHEME FOR SALMONELLA-PANAMA

We describe a genotyping scheme for salmonella panama. Defined probes specific for the 16S rRNA gene and the DNA insertion element IS200 wer e generated by PCR from S. panama and were used to probe genomic South ern blots made with enzymes selected to cut within and outside the pro bed sequences, Plasmid profiles were determined. The typeability and d iscriminatory po,ver of the individual methods were compared. Ribotypi ng,vith 16S rRNA gene probe alone was slightly more discriminatory tha n phage typing, but unlike the latter, ribotyping was able to type all strains. IS200 profiling was the single most discriminatory method fo r S. panama, having an index of discrimination (D) of 0.8 and 100% typ eability. Plasmid profiling, which had moderate discriminatory power b ut only 50% typeability, was valuable as an adjunct technique, The use of all three methods together or simply the combination of IS200 prof iling with the two most discriminatory enzymes and plasmid profiling y ielded a molecular typing scheme whose discriminatory power (D = 0.97) approached the maximum theoretical value. This should prove both usef ul and robust for epidemiological investigations of S. panama.