Characterization ofStreptococcus zooepidemicus(Lancefield group C) from human and selected animal infections

Abstract

SUMMARYWe assembled an international collection of strains from sporadic and epidemic human infection withStreptococcus zooepidemicus(Lancefield group C) for laboratory study. Cultural and physiological characteristics of the isolates were determined, including biotyping with the API 20 STREP test kit and susceptibility testing with penicillin, erythromycin and tetracycline. The strains were examined for bacteriocin production and sensitivity and typed with a specially developed group-C streptococcal bacteriophage system incorporating a panel of 14 phages. Results of these tests gave useful discrimination between many of the strains: differences were shown between each of the major outbreak strains, including those complicated by post-streptococcal glomerulonephritis.Serious group C streptococcal infection may be caused byS. zooepidemicusand isolates should be identified to species level; the application of a typing scheme such as this may help to distinguish epidemiological patterns of infection.