Typing of Group A streptococci from an urban area (Köln) in West Germany.

Two-hundred and twenty strains of Streptococcus pyogenes (group A streptococcus) from the urban area of Köln, West Germany have been typed by M precipitin and T agglutination tests. Determination of streptococcal nicotinamide adenine dinucleotide glycohydrolase (NADase) production and the serum opacity reaction (SOR) have also been performed. 65.5% of the isolates could be typed by the M precipitin reaction. 92.1% of the remaining strains could be identified by their T protein antigens and could be further subdivided according to their NADase/SOR pattern. Most of the M typable strains originated from upper respiratory tract infections (including scarlet fever), whereas the majority of the M nontypable streptocci had been isolated from skin, wound, and other non-respiratory sites.