Appearance of Virulent Bacteriophages in Lysogenic <i>E. coli</i> Cultures after Prolonged Growth in the Presence of Triethylenemelamine

Northrop, John H.

doi:10.1085/jgp.52.1.136

Cited by 4 publications

(2 citation statements)

References 8 publications

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“…Another evolutionary route the pathogen could take is to escape superinfection inhibition, which would allow it to gain access to hosts even when all the bacteria are infected [25]. However, in λ the rate of mutation towards such ultravirulent strains has been shown to be very small and is thus unlikely to affect the short-term evolutionary dynamics [26]. In the long term, however, the coevolution between superinfection inhibition and the resistance to superinfection inhibition may play a major role for the evolutionary maintenance of viral latency and the emergence of diversity in λ-like phages [27].…”

Section: Discussionmentioning

confidence: 99%

Evolution of Virulence in Emerging Epidemics

et al. 2013

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Theory predicts that selection for pathogen virulence and horizontal transmission is highest at the onset of an epidemic but decreases thereafter, as the epidemic depletes the pool of susceptible hosts. We tested this prediction by tracking the competition between the latent bacteriophage λ and its virulent mutant λcI857 throughout experimental epidemics taking place in continuous cultures of Escherichia coli. As expected, the virulent λcI857 is strongly favored in the early stage of the epidemic, but loses competition with the latent virus as prevalence increases. We show that the observed transient selection for virulence and horizontal transmission can be fully explained within the framework of evolutionary epidemiology theory. This experimental validation of our predictions is a key step towards a predictive theory for the evolution of virulence in emerging infectious diseases.

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Section: Discussionmentioning

confidence: 99%

Evolution of Virulence in Emerging Epidemics

et al. 2013

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“…EDTA more than doubled the frequency of streptomycinresistant and phage-producing cells in Bacillus megatherium 201. EDTA caused the induction of bacteriophages in B. megatherium 201 and Salmonella typhimurium, but not in lysogenic strains of E. coli or Corynebacterium diphtheriae (Eisenstark and Kirchner 1956;Northrop 1963Northrop , 1968Kozak and Dobrzański 1970).…”

Section: Genotoxicitymentioning

confidence: 99%

Final Report on the Safety Assessment of EDTA, Calcium Disodium EDTA, Diammonium EDTA, Dipotassium EDTA, Disodium EDTA, TEA-EDTA, Tetrasodium EDTA, Tripotassium EDTA, Trisodium EDTA, HEDTA, and Trisodium HEDTA

2002

Int J Toxicol

110

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EDTA (ethylenediamine tetraacetic acid) and its salts are substituted diamines. HEDTA (hydroxyethyl ethylenediamine triacetic acid) and its trisodium salt are substituted amines. These ingredients function as chelating agents in cosmetic formulations. The typical concentration of use of EDTA is less than 2%, with the other salts in current use at even lower concentrations. The lowest dose reported to cause a toxic effect in animals was 750 mg/kg/day. These chelating agents are cytotoxic and weakly genotoxic, but not carcinogenic. Oral exposures to EDTA produced adverse reproductive and developmental effects in animals. Clinical tests reported no absorption of an EDTA salt through the skin. These ingredients are likely, however, to affect the passage of other chemicals into the skin because they will chelate calcium. Exposure to EDTA in most cosmetic formulations, therefore, would produce systemic exposure levels well below those seen to be toxic in oral dosing studies. Exposure to EDTA in cosmetic formulations that may be inhaled, however, was a concern. An exposure assessment done using conservative assumptions predicted that the maximum EDTA dose via inhalation of an aerosolized cosmetic formulation is below that shown to produce reproductive or developmental toxicity. Because of the potential to increase the penetration of other chemicals, formulators should continue to be aware of this when combining these ingredients with ingredients that previously have been determined to be safe, primarily because they were not significantly absorbed. Based on the available data, the Cosmetic Ingredient Review Expert Panel found that these ingredients are safe as used in cosmetic formulations.

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The genetic toxicology of hydroxylamines

Marfey

Robinson

1981

Mutation Research/Reviews in Genetic Toxicology

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Appearance of Virulent Bacteriophages in Lysogenic E. coli Cultures after Prolonged Growth in the Presence of Triethylenemelamine

Cited by 4 publications

References 8 publications

Evolution of Virulence in Emerging Epidemics

Evolution of Virulence in Emerging Epidemics

Final Report on the Safety Assessment of EDTA, Calcium Disodium EDTA, Diammonium EDTA, Dipotassium EDTA, Disodium EDTA, TEA-EDTA, Tetrasodium EDTA, Tripotassium EDTA, Trisodium EDTA, HEDTA, and Trisodium HEDTA

The genetic toxicology of hydroxylamines

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