Rebecca C. Lancefield

A Micro Precipitin-Technic for Classifying Hemolytic Streptococci, and Improved Methods for Producing Antisera

Summary Methods are described for producing high-titered group-specific antisera for classifying hemolytic streptococci into groups. A description is also given of a reliable micro-precipitin technic which can be used with very small amounts of bacterial extract and antiserum. Attention is called to the occurrence of some non-hemolytic members of Groups B, C, D, and G. Since this communication was submitted for publication, Fuller has reported a method of extracting streptococci with formamide. 5

Type-specific polysaccharide antigens of group B streptococci

The type-specific antigen of Group B Type II streptococci has been prepared free of other known cell components. This antigen is a capsular polysaccharide containing D-galactose, D-glucose, N-acetyl-D-glucosamine, and a labile component which has not been chemically characterized. Extraction of Type II streptococci with cold TCA yielded this antigen which contained two serological determinants. A partial antigen with only one of the determinants was obtained by extraction with dilute HCl at 100°C. By means of the quantitative precipitin inhibition technique, a (β-D-galactopyranoside has been established as the determinant of the HCl-extracted polysaccharide. The second determinant, present solely in the TCA antigen, has not been identified.

PREVENTION OF STREPTOCOCCAL PHARYNGITIS AMONG MILITARY PERSONNEL AND THEIR CIVILIAN DEPENDENTS BY MASS PROPHYLAXIS.

MANY studies have described the incidence of streptococcal pharyngitis in military personnel,1 , 2 and more recently attention has been focused on the occurrence of this disease in nonmilitary popu...

Current Problems in Studies of Streptococci Second Griffith Memorial Lecture

A brief synopsis of the full lecture. ‘To bacteriologists Dr Fred GrifEth is universally known for his fundamental work of type transformation in pneumococci and for his studies on the classification of the haemolytic streptococci ( G f l t h , 1928). He early developed a new method of slide agglutination which he used with success on pathogenic streptococci isolated from infections in man. In 1934 he published a study of the first 27 types (Griffith, 1934). Precipitin reactions with the M antigen were the basis of studies in my laboratory of the serological types of haemolytic streptococci (Lancefield, 1928). Dr Griffith and I exchanged strains and sera and found that with very few exceptions we agreed on the typing results. The number of types has now risen to 55. In this second Griffith Memorial Lecture some of the significant advances in streptococcal research since 1941 are reported. ’ ‘It was found that a second antigen, designated T, stimulated antibodies which reacted in slide-agglutination tests (Lancefield, 1940). The specificity of the T antigen did not always agree with that of the M antigen (Lancefield, 1954). Some strains isolated from impetigo were classified by slide agglutination into the three main T-antigen patterns by Parker and others in 1955 (Parker, Tomlinson & Williams, 1955 ; Barrow, I 955). However, these strains gave no recognizable M-precipitin reaction. Identification of these strains was important because impetigo is often associated with acute glomerulonephritis. Search for previously unrecognized M-types among pyoderma strains uncovered at least four new types, two of these from acute glomerulonephritis (Anthony, Perlman & Wannamaker, 1967). It is now known that certain M-type infections with some strains are followed by epidemic glomerulonephritis, and infections with other strains of the same type occur in streptococcal epidemics unassociated with nephritis. Five or six types are now generally accepted as including nephritogenic strains (Johnson, Baskin, Beachey & Stollerman, 1968). Attempts to isolate a toxin, or other substances of significance in glomerulonephritis, from nephritogenic strains have been unsuccessful. ’ The Lecturer next discussed a few selected examples of immunological studies of the antigenic composition of group A streptococci, representing the trend of streptococcal research in recent years. The isolation and analysis of the streptococcal cell wall (Salton, 1952) and the localization of many antigenic components were stressed (McCarty, 1964). These studies showed that the mucopeptide is the only structural component of the rigid streptococcal cell wall left after removal of all other substances.

Note on the Susceptibility of Certain Strains of Hemolytic Streptococcus to a Streptococcus Bacteriophage

A bacteriophage active against certain mucoid strains of hemolytic streptococci, originally isolated by Clark and Clark 1 , was used in tests with a series of 119 strains of hemolytic streptococci which had been obtained from a variety of sources, some pathological and some normal. Of these, 37 strains were isolated from human sources, including 5 throat cultures from normal persons; 42 strains were recovered from mastitis in cows and from milk and cheese; 18 from lymphadenitis in guinea pigs; 7 from spontaneous rabbit infections with hemolytic streptococcus; 7 from pleuro-pneumonia, chronic endometritis and distemper in horses; 2 from pneumonia in foxes; 3 from streptococcus infections in swine; and 3 from a disease known as “slipped tendon” in chickens. The table shows the number of strains of hemolytic streptococcus which were susceptible to the Clark bacteriophage and the number insusceptible, as well as the source of the cultures. All susceptible strains, except the 6 of human origin, were strikingly affected by the action of this phage, and were further characterized by the formation on blood agar plates of mucoid colonies with exceptionally large zones of hemolysis. The susceptible human strains, on the contrary, did not form mucoid colonies, and were only slightly sensitive to the action of the phage and with much less regularity than the strains of animal origin. The addition of bacteriophage to susceptible cultures did not lead to the formation of plaques or “moth-eaten” colonies. This observation is in accord with the findings of others who have worked with bacteriophage active against hemolytic streptococci isolated from guinea pigs, and have rarely or never found such colonies. 1 , 2 , 3 Without the addition of bacteriophage, however, one of the strains in the present series occasionally showed “moth-eaten” colonies.