Serological characterization of group-A streptococci associated with skin sepsis in meat handlers.
A series of outbreaks of skin sepsis among meat handlers in England during 1974 and 1975 afforded an opportunity to study the group-A streptococci commonly isolated from the lesions. Few of these streptococci could be M typed with existing antisera. Intensive study of strains from two outbreaks of sepsis  in one abattoir in Shropshire led to the recognition of three new provisional M types. The streptococci were first sorted according to T-typing pattern and ability to produce opacity factor. Opacity-factor producing strains with the same T pattern were then screened for inhibition of opacity production by the sera of convalescents from the same outbreak. Finally, M antisera were made in rabbits against representative cultures. Sera against the three new provisional types were used to re-examine streptococci from 20 other outbreaks or incidents of sporadic infection among meat handlers. This increased the proportion of typable strains from 3% to 55%. Two of the new provisional types (nos. 2015 and 1658; both T25/Imp 19, opacity-factor positive) were confined to the Shropshire outbreak, but the third (no. 2681; T14, opacity-factor negative) was found among strains from meat workers in eight other geographically distinct areas. In all, 31% of 131 distinct strains from meat workers, but less than 1% of 2816 strains from other British sources, belonged to provisional type 2681. Thus, in Britain, one M-type of group-A streptococcus appears at present to be almost exclusively associated with sepsis in meat workers.
D000003:Abattoirs; D004196:Disease Outbreaks; D004739:England; D006801:Humans; D008462:Meat-Packing Industry; D009784:Occupational Diseases / Q000209:etiology* / Q000382:microbiology; D012621:Seasons; D018805:Sepsis / Q000209:etiology*; D012703:Serotyping; D012874:Skin Diseases, Infectious / Q000209:etiology* / Q000382:microbiology; D013290:Streptococcal Infections; D013297:Streptococcus pyogenes / Q000302:isolation & purification*