Changes in Typing Pattern of Phage-Type 80 Staphylococci

Abstract

SUMMARY : Three temperate phages isolated from lysogenic staphylococci of phage type 52/52A/80 were used to lysogenize strains of phage-type 80. Two of these phages belonged to serological group A and one to serological group F. Lysogenization of a strain of phage-type 80 with one of the phages (287') resulted in a change in the typing pattern from 80/81 to 52/52A/80. There was, therefore, a gain in sensitivity to phage 52 and 52A and a loss in sensitivity to phage 81. Lysogenization of type 80 strains with the second phage (581') caused a loss in sensitivity to phage 81, while lysogenization with phage 7287' caused a gain in sensitivity to phage 52 and 52A.Loss in sensitivity to phage 81 after lysogenization with phage 287' seems most probably due to specific prophage immunity since phages 287' and 81 belong to the same serological group (A) and may be closely related. Loss in sensitivity to phage 81 after lysogenization with phage 581' does not appear to be a case of specific prophage immunity since the two phages are serologically distinct and the phenomenon resembles examples of prophage interference observed in other organisms.Rountree & Freeman (1955) described a number of hospital epidemics in Australia caused by a strain of staphylococcus which was almost completely resistant to the routine typing phages then in use. However, the two group-I phages 52 and 52A produced a few plaques when applied undiluted to a lawn of the organisms, and phage 52A was 'adapted' to this new type of staphylococcus. The adapted phage is now known as phage 80 and strains lysed specifically by this phage as phage-type 80. A second phage known as 81 was isolated independently in Canada (Bynoe, Elder & Comtois, 1956); it is capable of lysing the majority of phage-type 80 strains. Such strains are therefore more accurately described as phage-type 80/81. Since, however, phage 81 is not included in the set of 21 basic phages used in Great Britain, the strains are usually reported simply as phage-type 80. The 81 reaction will be referred to in this paper only when relevant.Since the original description by Rountree & Freeman many epidemics caused by staphylococci of phage-type 80 have been described in different countries. During the past two or three years it has been noticed in this laboratory that, in some prolonged epidemics caused by phage-type 80, strains giving the typing pattern 52/52 A/80 were also isolated, particularly during the later part of the epidemic. The 'classical' phage-type 80 coccus is lysed only by phage 80 a t the routine test dilution (RTD), using the basic set of

Epidemiological and Genetical Study of Drug Resistance in Staphylococcus aureus

“…It was shown previously [2,15] that changes in phage typing pattern in staphylococci resulted from artificial lysogenization. It was reported by Asheshov and Rippon [1] and by Rountree [32] that certain changes in phage typing patterns which follow artificial lysogenization are the results of serologically specific prophage immunity. The phage typing pattern of type 80/81 strains was reported to be changed to 52/52A/80/81 after lysogenization by certain serological group A phages.…”

Plasmid profiling of epidemic staphylococci from around 1960: a comparison of epidemiological techniques

“…The general similarity of the phage group I isolates would not originally have caused problems since the strains were isolated from different wards or in different years. Asheshov & Rippon (1959) Naidoo, 1984).…”

Further Observations on Changes in the Phage-Typing Pattern of Phage Type 80/81 Staphylococci

“…They were as follows: strain 594, isolated from the same patient as strain 590 and presumed to have been converted from strain 590 in vivo. Lysogenic clones of this strain were used as the source of two converting phages and are described in detail below; strain 6346 DL, derived from strain 6346 which was lysogenized with a converting phage, 7287l, and subsequently cured (Asheshov & Rippon, 1959). This strain is believed to be completely non-lysogenic; strain 80 la, a mutant of P.S.…”

“…It seemed, therefore, that phage b might have its origin in a hitherto undetected prophage in P.S. 80 or else be a recombinant of such a hypothetical prophage with the phage a or a. Lysogenicity of type 80181 strains Previous attempts to demonstrate lysogenicity in type sol81 strains had been unsuccessful (Asheshov & Rippon, 1959;Rountree, 1959) but the appearance of phage b during the growth of phage a and n in these strains indicated that a further search should be made. When supernatant fluids of 2-4 hr.…”