Animal Strains of Group G Streptococci and their Serological Typing

Abstract

SUMMARY: A brief review of group G streptococci and their typing is given with particular reference to canine strains. Two of the Australian type strains of Simmons & Keogh (1944)) were found to be in the group phase and useless for comparative purposes. Four types Kennett, Maxie, Airedale and R51/755 were clearly defined in addition to the Australian types Harrison and Cuthell by reciprocal absorption tests using slide agglutination. Fifty-four other strains of which 35 were of animal and 19 of human origin were examined for type. Of the 38 strains from animal sources, 33 belonged to one of the two types Kennett or Maxie, strains of which came exclusively from animal sources. Six of the human strains and one of the animal ones were untyped.Type R51/755 which had been found previously by Maxted (1949) t o possess the M28 antigen owed its type-specificity entirely to this antigen and this was not found to be present in any of the other types.The substances responsible for type-specificity in types Kennett, Maxie, and Airedale differed from those of types Harrison and Cuthell and like that of type R51/755 appeared to be protein in nature. The type-specific substances of types Airedale and Maxie had exactly the same characters as the M28 antigen in being sensitive to peptic but resistant to tryptic digestion. The protein antigen of type Kennett differed from the other three protein type-specific substances in showing only moderate resistance to tryptic digestion.

Immunoglobulin-binding structure on bovine group G streptococci different from type III Fc receptors on human group G streptococci

“…These antigens are not restricted to group A organisms but have also been reported in some group G strains of human origin (12,19,24). Nonhuman group G strains have distinct surface antigens which have been used for serotyping of bovine isolates (21). The nature ofthese antigens is to our knowledge uncertain, but it seems likely that they represent surface components similar to those carried by human strains.…”

“…Group G streptococci also colonize various domestic animals and may produce significant illness (2,8,10,20,23,26). Serological studies of human as well as of animal group G streptococci have revealed antigenic heterogeneity of the bacterial cell surfaces and a number of serotypes in each group (21,31). Protein A-carrying staphylococci can react in a nonimmune way with the Fc portion of the antibody molecule (9,14).…”

A new scheme for serotyping group-G streptococci

“…Members of this group are known to cause disease in man, including endocarditis (MacDonald, 1939), epidemic pharyngitis (Hill et al, 1969) and neonatal septicaemia (Baker, 1974). Serological typing of group-G streptococci by slide-agglutination tests for their T antigens has been reported (Laughton and Davies, 1957;Hill et al, 1969;Efstratiou, 1983).…”