Characterization of a Transfer Factor Associated with Drug Resistance in Salmonella typhimurium

SUMMARYThe results presented in this paper confirm the existence of two types of tetracycline resistance in Shigella sonnei. One group of strains had a high level of resistance to tetracycline and oxytetracycline, with a variable level of minocycline resistance. The second group had a lower level of tetracycline resistance and were sensitive to minocycline. After conjugation with E. coli K12 the selected E. coli transconjugants had the same levels of resistance as the parent Sh. sonnei strain, with one exception. Sh. sonnei 87 was resistant to a high level of tetracycline, but was able to transfer only low level resistance. It is suggested that Sh. sonnei 87 carries two plasmids: pSUI, a conjugative plasmid conferring a low level of tetracycline resistance, and pSU2, a non-conjugative plasmid which confers a high level of resistance to tetracycline.

Section: Discussionmentioning

confidence: 99%

High and low level tetracycline resistance inShigella sonnei

Hawkins

Dale

1978

“…The A transfer factor and the T-A R factor restrict the lysis of type 36 by 24 of the 30 S. typhimurium typing phages, to produce type 6 (Anderson & Lewis, 1965 …”

Section: The Fertility Inhibition (Fi) Charactermentioning

confidence: 99%

The characterization of plasmids in the enterobacteria

Anderson¹,

Threlfall²

1974

Self Cite

121

“…The factor from 4M2563, the type strain of 125, also carried the genetic determinant for the production of colicin I (ColI+). M736, the type strain of type 6, isolated in 1945, carries a transfer factor yielding restriction identical with that of A, which converts type 36 into type 6 (Anderson & Lewis, 1965b). The R factor from the wild S. typhimurium type 6 strain 12R1373, isolated in 1971, was also A-like.…”

Section: Transfer Of 1 Factors and Transfer Factors To Type 36mentioning

confidence: 99%

“…Although all are 'I-like', their phage-restricting effects on strains of S. typhimurium are quite different. The A-like factors, the prototype of which was described by Anderson & Lewis (1965b), inhibit lysis by 24 of the 30 S. typhimurium typing phages, to produce phage type 6. The ColI-like factors inhibit lysis by only two typing phages, to give rise to type 125 (Anderson, 1966), and the factor from S. typhimurium 5M4750 inhibits lysis by 27 typing phages, to produce type 145.…”

Section: Transfer Of 1 Factors and Transfer Factors To Type 36mentioning

confidence: 99%

“…Anderson & Lewis (1965b) and Anderson (1966) found that some f-R factors restricted lysis by the Salmonella typhimurium, S. paratyphi B and S. typhi typing phages, reducing the sensitivity of the host strains in characteristic fashion, and thereby altering the 'phage type' of the salmonellas concerned. Carriage of the A transfer factor and its derivative R factor T-A, for example, reduced the sensitivity of S. typhimurium phage type 36 (= type 36), which is sensitive to all of the 30 S. typhimurium typing phages, to type 6, which is sensitive to only six of the phages.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bacteriophage restriction in Salmonella typhimurium by R factors and transfer factors

Anderson

Threlfall

Carr

et al. 1973

Self Cite

SUMMARYA total of 2716 R factors and transfer factors isolated from Escherichia coli and salmonellas of human and animal origin were studied for their phage-restrictive effects in Salmonella typhimurium phage type 36. All of 1402 wild fi+ factors were non-restricting. The F factor of E. coli K12 was unique among the F-like factors tested in that it inhibited lysis of type 36 by one typing phage. In contrast, eleven distinct changes in the phage type of 36 were produced by f-I-like factors. I like plasmids can thus be subdivided by this method.I-like R factors and transfer factors from human and animal enterobacteria were categorized by their phage-restrictive effects in type 36. Factors resembling A in this respect predominated among fi-I-like factor from human E9. coli and S. typhimurium and from porcine E. coli. A-like and ColI-like f-factors were equally distributed in bovine S. typhimurium. ColI-like factors were commonest in bovine and avian E. coli.