The Development of a Phage-Typing System for Group-B Streptococci

Serotyping and bacteriophage typing of human and bovine group-B streptococci

“…Phage typing has been used successfully in tracing the spread of group-B streptococci in hospitals (Stringer 1980). One conclusion of the present study is that the method can provide useful information, when combined with serotyping, on the ecology of the organism and the epidemiology of diseases that it causes.…”

“…It was found, however, to be suitable for the study of strains isolated from cows as well as from man. From the first, Stringer (1980) had noted that there was no specificity of phage pattern to serotype but that there was a predominance of particular patterns of lysis. In the present study most strains were lysed by two or three phages.…”

“…Type antisera were prepared by absorption of antisera made against the following reference strains: 090R (Ia), H36B (Ib), A909 (Ic), 18RS21 (11) and D136C (111) State Serum Institute, Copenhagen. The phage typing was performed by the procedure and with the phages described by Stringer (1980). The shortened set of 24 phages was used.…”

“…Bacteriophages that lyse group-B streptococci are known (Russell, Norcross and Kahn, 1969), and Stringer (1980) has described a phage-typing system with phages isolated from cultures of human origin. The aim of the present study was to compare the serotypes and phage types of strains of S. agalactiae isolated from healthy and diseased human subjects with strains isolated from cattle in different parts of Norway.…”

The evaluation of a phage-typing system for Listeria monocytogenes for use in epidemiological studies

“…Different geographical patterns of phage specificity have been observed for other organisms, t'.g., S. UUI'CUS (Parker, 1972). group-A streptococci (Skjold and Wannamaker, 1976) and group-B streptococci (Stringer, 1980). The reason for the decreased number of typable serogroup-4 strains when phage 28 was used could be due either to the bias introduced by the selection of index strains (i.e., because of the selection of typable strains from earlier batches), or to the unequal diqtribution of phage-lytic patterns observed over rtslativelq short periods of time (McLauchlin et al, 1986) as the strains typed with phage 28 included a large proportion of recent isolates which were phage typed in the later stages of the study.…”