Genetic typing methods applied to the differentiation of clonal lines among Salmonella enterica serogroup G strains causing human salmonellosis

In Spain, in November 1995, an epidemiological alert recommended the surveillance of Salmonella serogroup G. The nine clinical isolates collected after and the four collected before the alert in Asturias were differentiated into six clonal lines by the combination of results from HincII ribotyping, PCR ribotyping, and RAPD typing using primers named A and S. The seven Gumpensis isolates showed identical DNA fingerprinting with the four typing procedures falling into a line. Six of these were collected during May-August from people living in a single health area suggesting that they could be associated with a community outbreak. The four Worthington isolates fell into three other lines, one Poona isolate into another line and one Havana isolate into another. 100% typeability was shown with all methods. The reproducibility of HincII ribotyping was better than that of PCR-based methods, although these were less time-consuming. The highest discriminatory power was obtained with HincII ribotyping and RAPD typing using primer A.