Long-term survival and plasmid maintenance of Escherichia coli in marine microcosms

Byrd, Jeffrey J.

doi:10.1016/0168-6496(93)90019-4

Cited by 3 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yet, bacteria can maintain plasmids that have no evident benefit despite the costs [2,[18][19][20][21]. Plasmids can spread horizontally at sufficiently high rates to explain this seemingly paradox [22].…”

Section: Introductionmentioning

confidence: 99%

Plasmid carriage and the unorthodox use of fitness in microbial evolution

Reding

2019

Preprint

View full text Add to dashboard Cite

Microbes without plasmids divide faster than those harbouring them. Microbiolo-6 gists rely on this difference in growth rate between both types to foresee whether 7 a plasmid will be maintained, or else purged by the host to avoid extinction. Here 8 I report that plasmids change multiple life-history traits, and I demonstrate that 9 growth rate alone can be a bad predictor for plasmid maintenance. Pairwise com-10 petition experiments between two constructs of Escherichia coli-one of which car-11 ries a plasmid-revealed that harbouring plasmids can also increase yield and delay 12 growth (lag). Crucially, yield engaged in a trade-off with growth rate. The plasmid 13 borne by one construct (R), non-transmissible and with a tetracycline-resistance 14 gene, reduced its host's growth rate by 20%. However, given this trade-off, R 15 outgrew its sensitive counterpart (S) in the absence of tetracycline when the com-16 petition favoured yield over growth rate. Trade-offs like this can challenge the 17 application of concepts that depend on carriage costs: R-mutants with additional 18 copies of the plasmid exploited this trade-off, and were selected for in tetracycline 19concentrations below the so-called 'minimal selective concentration'-the lowest an-20 timicrobial concentration thought to select for resistant mutants. My data suggests 21 that carriage costs interfere with multiple traits. Whether plasmids are costly to 22 maintain will therefore depend on the relationship between them, and which is un-23 der strongest selection. It also demonstrates that each trait reports different drug 24 sensitivity, exposing new opportunities for therapy design. 26Plasmids are independent genetic elements that complement the chromosome of prokaryotes 1,2 27 and eukaryotes 3 alike. They can benefit cells harbouring them-notoriously in the form of 28 resistance to antibiotics-but the metabolic costs associated with their upkeep can reduce the 29 host's growth rate 2,4 . Clinicians and evolutionary biologists exploit the sensitivity of growth rate 30 to plasmid carriage, using pairwise competition experiments to estimate the costs of plasmid 31 maintenance 5-8 and whether a plasmid will be maintained through time. Their conclusion is 32 straightforward: microbes without plasmids multiply faster in environments where plasmids are 33 not beneficial, and overthrow microbes harbouring them 4,7 . 34Plasmids will therefore be preserved when the benefits they provide outweigh the reduction 35 in growth rate that they impose. Bacteria, however, can maintain plasmids that have no evident 36 benefit-despite reducing their growth rate 2,[9][10][11] . So, where is the hidden benefit? Plasmids are 37 2 known to reduce the host's growth rate, but the metabolic alterations that plasmids introduce 38 are unclear [12][13][14][15] . Here I asked whether growth rate is the only life-history trait that is sensitive 39 to plasmid carriage, and it is not. I analysed the growth dynamics of two identical constructs 16 40 of Escherichia coli, one of which ...

show abstract

Section: Introductionmentioning

confidence: 99%

Plasmid carriage and the unorthodox use of fitness in microbial evolution

Reding

2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Horizontal gene transfer should be considered in risk assessment, when genetically modified micro‐organisms (GMM) are released into the environment, either intentionally or accidentally. Escherichia coli , one of the most widely used bacteria for the synthesis of recombinant products, may survive longer than expected in river water [1], or sea water [2, 3]. It has recently been shown to establish itself in biofilms [4, 5].…”

Section: Introductionmentioning

confidence: 99%

Gene transfer between bacteria within digestive vacuoles of protozoa

Schlimme

Marchiani

Hanselmann

et al. 2006

FEMS Microbiology Ecology

View full text Add to dashboard Cite

The occurrence of horizontal gene transfer between bacteria within digestive vacuoles and faecal pellets of the protozoan Tetrahymena pyriformis was investigated. More than 90% of the egested faecal pellets of T. pyriformis, added as predator to a suspension of Escherichia coli, contained viable bacteria. In a mixed population, containing donor (plasmid RP4) and recipient E. coli cells, the presence of T. pyriformis increased conjugational gene transfer by three orders of magnitude. Since the protozoa formed an average of 12–13 digestive vacuoles per cell, each protozoan had statistically egested one or more transconjugants. Thus, we show for the first time that digestive vacuoles of free‐living protozoa appear to be an important ecological micro‐niche, where gene transfer by conjugation (or retromobilisation) will be favoured. So far, digestive vacuoles have been ignored in genetic and ecological studies. This micro‐biotope provides a selective pressure which might enhance the acquisition of virulence genes in cases of mutual interactions between genetically modified micro‐organisms and wild‐type pathogens. This finding is important for biosafety considerations.

show abstract

Microbiological Safety of Drinking Water

Szewzyk

Manz

et al. 2000

Annu. Rev. Microbiol.

474

320

View full text Add to dashboard Cite

Emerging pathogens in drinking water have become increasingly important during the decade. These include newly-recognized pathogens from fecal sources such as Cryptosporidium parvum, Campylobacter spp., and rotavirus, as well as pathogens that are able to grow in water distribution systems, like Legionella spp., mycobacteria, and aeromonads. To perform a risk analysis for the pathogens in drinking water, it is necessary to understand the ecology of these organisms. The ecology of the drinking-water distribution system has to be evaluated in detail, especially the diversity and physiological properties of water bacteria. The interactions between water bacteria and (potential) pathogens in such diverse habitats as free water and biofilms are essential for the survival or growth of hygienically relevant organisms in drinking water. Results of epidemiological studies together with ecological data are the basis for effective resource protection, water treatment, and risk assessment.

show abstract

Long-term survival and plasmid maintenance of Escherichia coli in marine microcosms

Cited by 3 publications

References 15 publications

Plasmid carriage and the unorthodox use of fitness in microbial evolution

Plasmid carriage and the unorthodox use of fitness in microbial evolution

Gene transfer between bacteria within digestive vacuoles of protozoa

Microbiological Safety of Drinking Water

Contact Info

Product

Resources

About