Variation in Distribution of Type and Group Substances in Smooth-Phase Cultures of Group A Beta Hemolytic Streptococci

In Vitro Variation in Group a Streptococci With Special Reference to Streptolysin Formation

“…The problem of variation in hemolytic streptococci still remains in a confused state in spite of the extensive studies by previous workers Dawson et al, 1938;Hadley and Hadley, 1938;Mellon, 1948). It is commonly accepted that the diversity of methods and techniques is responsible in a great measure for this confusion.…”

“…Studies on variation in Streptoco s hemolyticus have been reported by a number of observers, but no parallelism has been demonstrated between the dissociational behavior of the organisms and its ability to produce streptolysins. A detailed study of the morphological variation of streptococcal colonies with relation to type-specific substance, virulence, toxin, and fibrinolytic activity was made by Todd and Lancefield (1928), Dawson et al (1938), and Hadley and Hadley (1938). However, the correlation of colonial variation, cellular morphologic variation, and degree of streptolysin formation in derivatives of a single strain have not been described.…”

Bacterial Dissociation

“…Independent variation between polysaccharide antigens and virulence has been demonstrated for Salmonella typhimurium (145). Waaler (242) has observed numerous examples of minor and large changes in the colonial morphology of dysentery bacilli without corresponding modification in the antigenic behavior (a variant having the S antigen could show a typical rough colony morphology, and an R variant with a rough morphology could change its morphology without any simultaneous alteration in the antigen); similar independent variation of antigenicity and colony morphology have been studied in Noguchia granulosis (95), hemolytic streptococci (91,162), pneumococci (44), and B. abortus (26,31,163), as well as in typhoid bacilli where independent changes of the "Vi" antigen and colony morphology have been described (62,70). A change from "specific" antigens to group antigens without colonial type variation has been recorded in the Shigella paradysenteriae group (231); and in flagellated species the ability to form flagella has been demonstrated to vary independently from the S --* R variation (cf., 60).…”

Conditions Contributing to Streptococcal Virulence

“…This special problem has been referred to earlier byHadley and Hadley (1938) in connection with the significance of the group and type-specific antigenic fractions in Betahemolytic streptococci of smooth phase recently derived from rough by enforced transformation in vitro. This problem relates to the possible function of the rough-phase culture (reproductively mature form) in affording a basis for the rejuvenation and modification of specific bacterial attributes.…”