The serotypes ofBordetella pertussisisolated in Great Britain between 1941 and 1968 and a comparison with the serotypes observed in other countries over this period

Abstract

SUMMARYClassification, by agglutinogens, of 634 isolates ofBordetella pertussiscollected from 1941 to 1968 in Great Britain demonstrated that a change from a predominantly 1,2,0,4 serotype (75% of those examined during 1941–4) to a predominantly 1,0,3,0 serotype (73% of those examined during 1966–8) occurred sometime after 1953. Furthermore, evidence from the examination of isolates collected between 1941 and 1953 suggests that the change may have been gradual. Isolates of serotype 1,2,3,4 made up 20–30% of the total of our cross-country selection for the periods 1941–4, 1946–9, 1950–3 and 1966–8, but over shorter periods in individual areas the percentage varied from negligible to as high as half of those isolated. Results from other countries show a similar drift towards a 1,0,3 serotype but more often from a 1,2,3 than from 1,2,0 serotype.The value, in epidemiological studies, of extended information obtained by monospecific typing sera to all six, rather than only two or three agglutinogens, and confirmation of the results by agglutinin production is demonstrated: for instance not all 1,0,3 isolates were identical.

The stability of the serotypes ofBordetella pertussiswith particular reference to serotype 1,2,3,4

“…There always appear to be at least some 1,2,3,4 strains in any community; in Britain the numbers of these isolated have 285 been constant for 30 years, whilst there were wide fluctuations of incidence of isolates of other serotypes (Bronne-Shanbury et al 1976). …”

“…The reason for the complete change of infecting serotype as happens over a period of years (Preston, 1963;Bronne-Shanbury et al 1976) is unknown. Virulence and rate of growth are not related to the serotype of an isolate.…”

“…Some workers have called these cultures 'mixed'. This concept has now been extended by Stanbridge & Preston (1974b) (Bronne-Shanbury, Miller & Standfast, 1976). In our laboratory the stability of types 1,0,3,0 and 1,2,0,4 contrasts strongly with that of 1,2,3,4.…”

“…Strains used as control suspensions in the typing of isolates by direct agglutination and agglutinin production were as described previously (Bronne-Shanbury, 1976;Bronne-Shanbury et at. 1976).…”

“…These were (a) direct agglutination of the whole culture by monospecific typing sera 1, 2, 3 and 4 to identify the antigens (Bronne-Shanbury et al 1976), (b) agglutinin production and identification of the agglutinins (Bronne-Shanbury, 1976) Mixing of strains of serotype 1,0,3,0 and 1,2,0,4 On solid medium. The strains were grown separately on BG plates at 360 C. An 18-24 hr.…”