On the drug-resistance of enteric bacteria

Mitsuhashi, Susumu; Hashimoto, Hajime; Morimura, Masato; ATSUMI, Kamesaburo; TANAKA, Sanjuro; Takahashi, Hirouchi; Harada, Kenji; Kameta, Mitsuo; Suzuki, Mitsue; MATSUYAMA, Tatsuo

doi:10.3412/jsb.15.1120

Cited by 7 publications

(4 citation statements)

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“…It was shown that most of the R factors carried the following genetic properties: ability to transfer with the host chromosome, i.e., R-mating (mat+) [29]; autonomous replication (rep+) [13]; conjugal transferability (tra+) [27]; inhibition of the F-mating (fi+ or ifm+) [2,4,26,31], and inhibition of superinfection with other R factor (irs+) [3,6,12,20,22].…”

Section: Methodsmentioning

confidence: 99%

“…It has been reported that R factors have the following genetic characters, (1) inhibition of F-mating (ifm+ or fi+) [2,4,26, 31], (2) inhibition of R factor superinfection (irs+) [3,6,12,20,22], and (3) restriction and modification of bacteriophage by R factor (suppression of phage proliferation; spp+) [37,38]. To know the genetic properties of the T95 factor, genetic characters such as ifm, irs and spp were compared with those of R factor.…”

Section: Genetic Properties Of T95 Factormentioning

confidence: 99%

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Genetic Properties of a T Factor and T‐r Recombinants

Kameda

Suzuki

Nakajima

et al. 1970

Japanese Journal of Microbiology

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Genetic studies have shown that one of the transfer (T) factors , T95, carries the following genetic properties: autonomous replication (rep+), conjugal transmission (tra+), transmission of the host chromosome (mat+), inhibition of F-mating (ifm+ or fi+), inhibition of superinfection with R factor (irs-), and suppression of phage proliferation (spp-). An Escherichia coli K12 strain carrying T95 factor is insensitive to male phages (f1 and f2). These facts indicated that the T95 factor is a sex factor but different from the F factors. By the interaction between T95 factor and the nontransferable resistance determinants; r21 (tet) for tetracycline resistance and r3 (kan) for kanamycin resistance, recombinants, T-tet, T-kan, and T-tet-kan, factors were obtained. These are capable of conferring drug-resistance and are conjugally transmissible as a single genetic unit. E. coli K12 strains carrying T95 or T-tet factor were insensitive to male phages and T-tet (probably T95) factor was transmitted sexually at about 10-5 transmission frequency after 1 hr of mixed culture. On the contrary, E. coli K12 strains carrying T-kan or T-tet-kan factor were found to become sensitive to male phages and their transmission frequency was 102 to 103-fold higher than that of T-tet factor. As a result of these findings, we concluded that the pili formation of T95 or T-tet factor is in a repressed state but the formation of a recombinant between T95 (or T-tet) and r3 (kan) determinants results in the derepression of pili formation.In previous papers [17,24], we presented three mechanisms involved in the acquisition of transmission of otherwise nontransferable resistance (r) determinants, 1) the resistance determinant which is integrated into the bacterial chromosome is transferred accompanying chromosomal transfer by sex factors such as F, R, and T factors, 2) acquisition of transferability of a nontransferable R factor which exists extrachromosomally, by complementation of episomic elements such as F, R, and T factors, and 3) formation of a recombinant between an r determinant and sex factors, resulting in the formation of F-r, R-r, and T-r factors [8,10,17]. This paper deals with the genetic properties of the T factors and of the recombinant T-r factors. MATERIALS AND METHODSStrains. Derivative strains of Escherichin coli K12 were used. The abbreviations and symbols of various markers were assigned according to the symbols described 339 340 M. KAMEDA ET AL.

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Section: Methodsmentioning

confidence: 99%

Section: Genetic Properties Of T95 Factormentioning

confidence: 99%

Genetic Properties of a T Factor and T‐r Recombinants

Kameda

Suzuki

Nakajima

et al. 1970

Japanese Journal of Microbiology

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“…These reports came from Japan where Ochiai et al (1959), Akiba et al (1960), and Mitsuhashi et al (1961) had discovered naturally occurring antibiotic resistance in Shigella bacteria. These are gram-negative bacteria that include S. dysenteriae bacteria responsible for dysentery and they are also closely related to Salmonella and E. coli.…”

Section: Bacterial Conjugation and The Acquisition Of Antibiotic Resimentioning

confidence: 99%

Historical and Epistemological Perspectives on What Horizontal Gene Transfer Mechanisms Contribute to Our Understanding of Evolution

Gontier

2015

Interdisciplinary Evolution Research

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Since the 1990s, results coming in from molecular phylogenetics necessitate us to recognize that Horizontal Gene Transfer (HGT) occurs massively across all three domains of life. Nonetheless, many of the mechanisms whereby genes can become transferred laterally have been known from the early twentieth century onward. The temporal discrepancy between the first historical observations of the processes, and the rather recent general acceptance of the documented data, poses an interesting epistemological conundrum: Why have incoming results on HGT been widely neglected by the general evolutionary community and what causes for a more favorable reception today? Five reasons are given: (1) HGT was first observed in the biomedical sciences and these sciences did not endorse an evolutionary epistemic stance because of the ontogeny/phylogeny divide adhered to by the founders of the Modern Synthesis.(2) Those who did entertain an evolutionary outlook associated research on HGT with a symbiotic epistemic framework. (3) That HGT occurs across all three domains of life was demonstrated by modern techniques developed in molecular biology, a field that itself awaits full integration into the general evolutionary synthesis. (4) Molecular phylogenetic studies of prokaryote evolution were originally associated with exobiology and abiogenesis, and both fields developed outside the framework provided by the Modern Synthesis. (5) Because HGT brings forth a pattern of reticulation, it contrasts the standard idea that evolution occurs solely by natural selection that brings forth a vertical, bifurcating pattern in the "tree" of life. Divided into two parts, this chapter first reviews current neo-Darwinian "tree of life" versus reticulate "web of life" polemics as they have been debated in high-profile academic journals, and secondly, the historical context of discovery of the various means whereby genes are transferred laterally is sketched. Along the way, the reader is introduced to how HGT contradicts some of the basic tenets of the neo-Darwinian paradigm.

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“…As described previously [6], the R91(TC) factor obtained by transduction of Rio(TC.CM.SM.SA) with phage epsilon, was shown to be defective in various episomic properties compared with the wild type R factor; was nontransferable (t-), lost of the R-mating property (m-) [28], loss of the capacity of autonomous-replication (re-) [13], and loss of episomic interference against infection with other episomes (iF-) [2,16,25,29,30] and (iR-) [3,12,21].…”

Section: The Genetic Properties Of Recombinantsmentioning

confidence: 99%

Drug Resistance of Enteric Bacteria

Harada¹,

Kameda²,

Suzuki³

et al. 1967

Japanese Journal of Microbiology

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A nontransferable R21 (TC) factor was obtained by transduction of R10 (TC.CM.SM. SA) with phage epsilon in group E Salmonella. The R21 (TC) factor acquired transmissibility by the normal conjugal process when group E Salmonella strains harboring R21 (TC) factor were infected with wild-type F or R16 (CM) factor. This transmissibility at high frequency was accounted for by the formation of the recombinant F TC and R16 (CM) TC factors. The F TC and R16 (CM) TC factors were genetically the same as the original F and R16 (CM) factors, except for the ability to confer TC resistance. In the transduction of F TC factor with phage P1, a dF TC (d: defective) factor was obtained that was defective in many F properties, such as the ability to introduce host chromosome and produce male substance, but was capable of transducing TC resistance (dF TCinfection) at low frequency.

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On the drug-resistance of enteric bacteria

Cited by 7 publications

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Genetic Properties of a T Factor and T‐r Recombinants

Genetic Properties of a T Factor and T‐r Recombinants

Historical and Epistemological Perspectives on What Horizontal Gene Transfer Mechanisms Contribute to Our Understanding of Evolution

Drug Resistance of Enteric Bacteria

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