Mutant Drug Resistant Factors of High Transmissibility

Meynell, Elinor; Datta, Naomi

doi:10.1038/214885a0

Cited by 271 publications

(119 citation statements)

References 27 publications

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“…The numbers of flexible pili were greatly increased (Fig. 1 a) in newly infected cells obtained by the method of Bradley (1980 b), indicating that the normal repression of pilus synthesis was temporarily lifted after transfer, as occurred with plasmids R64 or R144 of Inch (Meynell & Datta, 1967). No parallel increase in the numbers of rigid pili was observed.…”

Section: E Nugent and Othersmentioning

confidence: 75%

pHH502, a Plasmid with IncP and Incl Characters, Loses the Latter by a Specific recA-independent Deletion Event

Nugent¹,

Ellis²,

Datta³

et al. 1982

Microbiology

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Plasmid pHH502, of molecular weight 70 x lo6, determined resistance to tetracycline, chloramphenicol, trimethoprim, sulphonamides and mercuric chloride and was incompatible with members of IncP and I n c h It resembled other plasmids of IncIcc in the following properties : it determined pili that were morphologically and serologically Ia pili, whose production was repressed in established plasmid-carrying (R+) cultures ; its transfer was equally efficient in liquid or on solid medium; it exerted surface exclusion against other I n c h plasmids; it was non-transferable to Proteus. In a reproducible, recA-independent event, pHH502 gave rise to pHH502-1, a plasmid of molecular weight 40 x lo6, lacking determinants for resistance to tetracycline and chloramphenicol and all detectable IncIa characteristics. pHH502-1 was incompatible only with IncP plasmids and resembled other IncP plasmids in determining constitutive production of rigid pili, in its surface exclusion, in transferring at greater frequency on solid than in liquid medium and in being transmissible to Proteus mirabilis. It differed from other IncP plasmids in the morphology and serological type of its pili and in failing to transfer to Pseudomoms aeruginosa or Acinetobacter calcoaceticus. Small numbers of pHH502-1 rigid pili were present on bacteria carrying pHH502. Possible mechanisms for the generation of pHH502 and pHH502-1 are discussed.

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Section: E Nugent and Othersmentioning

confidence: 75%

pHH502, a Plasmid with IncP and Incl Characters, Loses the Latter by a Specific recA-independent Deletion Event

Nugent¹,

Ellis²,

Datta³

et al. 1982

Microbiology

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“…R1-16 is a deletion mutant of plasmid R1-19, which is itself a derepressed mutant of plasmid R1 with a high frequency of conjugation (Meynell and Datta, 1967). Plasmid R1-16 was chosen because it lacks all of the resistance determinants, except kanamycin (Goebel et al, 1977).…”

Section: Construction Of the Tram Mutationsmentioning

confidence: 99%

TraM of plasmid R1 controls transfer gene expression as an integrated control element in a complex regulatory network

Pölzleitner

Zechner

Renner

et al. 1997

Molecular Microbiology

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SummarySite-directed mutagenesis was used to investigate the functions of the traM gene in plasmid R1-mediated bacterial conjugation. Three mutant alleles, a null mutation, a sense mutation and a stop mutation, were recombined back into the R1-16 plasmid, a transferderepressed (finO ¹ ) variant of plasmid R1. The frequency of conjugative transfer of the traM null mutant derivative of R1-16 was 10 7 -fold lower than that of the isogenic parent plasmid, showing the absolute requirement for this gene in conjugative transfer of plasmid R1. Measurements of the abundance of plasmid specified traJ, traA and traM mRNAs, TraM protein levels, and complementation studies indicated that the traM gene of plasmid R1 has at least two functions in conjugation: (i) positive control of transfer gene expression; and (ii) a function in a process distinct from gene expression. Since expression of the negatively autoregulated traM gene is itself affected positively by the expression of the transfer operon genes, this gene constitutes a decisive element within a regulatory circuit that co-ordinates expression of the genes necessary for horizontal DNA transfer. Based on our studies, we present a novel model for the regulation of the transfer genes of plasmid R1 that might also be applicable to other IncF plasmids.

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“…Allan Campbell (1962 ) had just proposed his model for insertion and excision of phage lambda DNA in and out of the bacterial genome, and research was beginning to extend the "Campbell Model" by identifying the special sites and proteins that carry out this particular case of what was then called "illegitimate recombination." And Naomi Datta and Elinor Meynell at MGRU were extending the work of Tsutomu Watanabe (1963) by examining the plasmids that encoded the resistances bacteria had evolved to counter widespread antibiotic chemotherapy (Meynell & Datta, 1967).. The bacterial genetics all around me had little to do with the classical genetics developed in the first half of the 20 th Century, before we knew about DNA -or before many people believed that bacteria had any genetics at all.…”

Section: Personal History: Transposable Elements Adaptive Mutation Amentioning

confidence: 99%

Bacteria are small but not stupid: cognition, natural genetic engineering and socio-bacteriology

Shapiro

2007

Studies in History and Philosophy of Science Part C: Studies in

172

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40 years experience as a bacterial geneticist have taught me that bacteria possess many cognitive, computational and evolutionary capabilities unimaginable in the first six decades of the 20 th Century. Analysis of cellular processes such as metabolism, regulation of protein synthesis, and DNA repair established that bacteria continually monitor their external and internal environments and compute functional outputs based on information provided by their sensory apparatus. Studies of genetic recombination, lysogeny, antibiotic resistance and my own work on transposable elements revealed multiple widespread bacterial systems for mobilizing and engineering DNA molecules. Examination of colony development and organization led me to appreciate how extensive multicellular collaboration is among the majority of bacterial species. Contemporary research in many laboratories on cell-cell signaling, symbiosis and pathogenesis show that bacteria utilize sophisticated mechanisms for intercellular communication and even have the ability to commandeer the basic cell biology of "higher" plants and animals to meet their own needs. This remarkable series of observations requires us to revise basic ideas about biological information processing and recognize that even the smallest cells are sentient beings.

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Mutant Drug Resistant Factors of High Transmissibility

Cited by 271 publications

References 27 publications

pHH502, a Plasmid with IncP and Incl Characters, Loses the Latter by a Specific recA-independent Deletion Event

pHH502, a Plasmid with IncP and Incl Characters, Loses the Latter by a Specific recA-independent Deletion Event

TraM of plasmid R1 controls transfer gene expression as an integrated control element in a complex regulatory network

Bacteria are small but not stupid: cognition, natural genetic engineering and socio-bacteriology

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