ES18, a general transducing phage for smooth and nonsmooth Salmonela typhimurium
1970; Elsevier BV; Volume: 42; Issue: 3 Linguagem: Inglês
10.1016/0042-6822(70)90308-9
ISSN1096-0341
AutoresTseng‐tong Kuo, B. A. D. Stocker,
Tópico(s)Aquaculture disease management and microbiota
ResumoBacteriophage ES18, derived from typing phage 18 of the Salmonella typhimurium phage-typing scheme of Callow, is hear-labile and serologically and morphologically unlike phage P22 (a typical phage of Boyd's group A). Unlike phage P22 it attacks all classes of nonsmooth, as well as smooth, derivatives of LT2 lines “cured” of prophage Fels 2. A host-range variant, ES18.h1, overcomes the (partial) resistance conferred by lysogeny for Fels 2. Phage ES18 does not lysogenize pro deletion mutants lacking the preferred P22 prophage integration site. Lysogeny for P22 confers immunity to ES18, but ES18 lysogens are still sensitive to P22. Phage ES18 is a general transducing phage, effecting both complete and abortive transduction. Experiments to demonstrate transduction must take account of the very slow adsorption rate of this phage. The observed frequency of (complete) transduction of various loci by ES18 was lower, by a factor of 10–100, than the corresponding rates of transduction by phage P22. Lysogeny of the recipient for P22 increased the yield of transductants evoked by ES18 (though it lowered the yield of P22 transductants). For several pairs of linked loci the rates of cotransduction by ES18 and by P22 were about the same; this suggests that the chromosome fragments present in transducing particles of the two phages are of similar lengths. The activity of ES18 and ES18.h1 on nonsmooth mutants makes them useful for the transductional mapping of rfa genes in S. typhimurium.
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