The presence of muramidase released protein and extracellular factor protein in various serotypes ofStreptococcus suisisolated from diseased and healthy pigs in Spain

Abstract

A total of 142 strains from different serotypes ofStreptococcus suisisolated in Spain from diseased pigs (88 strains) and healthy carrier pigs (54 strains) were studied for the presence of a muramidase released protein (MRP) and an extracellular factor (EF). The following five phenotypes:MRP+EF+,MRP+EF–,MRP–EF+,MRP+EF* andMRP*EF– were detected. A high percentage ofS suisserotype 2 strains isolated from diseased pigs (84 per cent) belonged to phenotype MRP+EF+, but this phenotype has also been noticed in other serotypes (serotypes 1, 1/2 and 14). Both proteins were detected inS suisserotype 2 strains (26%) isolated from healthy carrier pigs and one of both proteins in serotypes 1 and 14 (phenotypeMRP+EF*). The isolation ofS suisstrains from healthy pigs which have shown both proteins may support the epidemiological significance of these carriers in the maintenance, transmission and distribution of virulent strains within and between swine farms.