scholarly journals Phage efficacy in infecting dual-strain biofilms ofPseudomonas aeruginosa

2019 ◽  
Author(s):  
Samuele Testa ◽  
Sarah Berger ◽  
Philippe Piccardi ◽  
Frank Oechslin ◽  
Grégory Resch ◽  
...  
Keyword(s):  
Liquid Culture ◽  
Phage Infection ◽  
Lytic Phage ◽  
Bacterial Strains ◽  
Strain Pao1 ◽  
Narrow Host Range ◽  
Structured Population ◽  
Additional Protection ◽  
Spatially Structured Population ◽  
Sensitive Population

Bacterial viruses, or phage, play a key role in shaping natural microbial communities. Yet much research on bacterial-phage interactions has been conducted in liquid cultures involving single bacterial strains. Critically, phage often have a very narrow host range meaning they can only ever target a subset of strains in a community. Here we explore how strain diversity affects the success of lytic phage in structured communities. In particular, we infect a susceptiblePseudomonas aeruginosastrain PAO1 with lytic phage Pseudomonas 352 in the presence versus absence of an insensitiveP. aeruginosastrain PA14, in liquid culture versus colonies growing on agar. We find that competition between the two bacterial strains reduces the likelihood of the susceptible strain evolving resistance to the phage. This result holds in liquid culture and in colonies. However, while in liquid the phage eliminate the whole sensitive population, colonies contain refuges wherein bacteria can remain sensitive yet escape phage infection. These refuges form mainly due to reduced growth in colony centers. We find little evidence that the presence of the insensitive strain provides any additional protection against phage. Our study reveals that living in a spatially structured population can protect bacteria against phage infection, while the presence of competing strains may instead reduce the likelihood of evolving resistance to phage, if encountered.

scholarly journals Spatial structure affects phage efficacy in infecting dual-strain biofilms of Pseudomonas aeruginosa

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Samuele Testa ◽  
Sarah Berger ◽  
Philippe Piccardi ◽  
Frank Oechslin ◽  
Grégory Resch ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Spatial Structure ◽  
Phage Infection ◽  
Lytic Phage ◽  
Bacterial Strains ◽  
Strain Pao1 ◽  
Resistance Evolution ◽  
Strain Competition ◽  
Evolution Of Resistance ◽  
Phage Population

Abstract Bacterial viruses, or phage, are key members of natural microbial communities. Yet much research on bacterial-phage interactions has been conducted in liquid cultures involving single bacterial strains. Here we explored how bacterial diversity affects the success of lytic phage in structured communities. We infected a sensitive Pseudomonas aeruginosa strain PAO1 with a lytic phage Pseudomonas 352 in the presence versus absence of an insensitive P. aeruginosa strain PA14, in liquid culture versus colonies on agar. We found that both in liquid and in colonies, inter-strain competition reduced resistance evolution in the susceptible strain and decreased phage population size. However, while all sensitive bacteria died in liquid, bacteria in colonies could remain sensitive yet escape phage infection, due mainly to reduced growth in colony centers. In sum, spatial structure can protect bacteria against phage infection, while the presence of competing strains reduces the evolution of resistance to phage.

scholarly journals Spatially structured population dynamics in feral oilseed rape

2004 ◽  
Vol 271 (1551) ◽  
pp. 1909-1916 ◽  
Author(s):  
Michael J. Crawley ◽  
Susan L. Brown
Keyword(s):  
Population Dynamics ◽  
Oilseed Rape ◽  
Structured Population ◽  
Structured Population Dynamics ◽  
Spatially Structured Population

UTILIZATION OF MILK AND ANIMAL FAT BY MICROORGANISMS – POTENTIAL PRODUCERS OF LIPASES AND ESTERASES

2020 ◽  
pp. 44-45
Author(s):  
D. Ivasenko ◽  
P. Bukhtiyarova ◽  
D. Antsiferov ◽  
Y. Frank
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Acid Composition ◽  
Liquid Culture ◽  
Culture Media ◽  
Bacterial Strains ◽  
Animal Fat ◽  
Pure Cultures

Analysis of fatty acid composition in liquid culture media after lipophilic bacterial strains cultivation was carried out. Pure cultures were earlierisolated from fat-containing wastes and cultivated on media with diverse fat sources. It was shown that microorganisms hydrolyze animal and milk fats to free fatty acids.

scholarly journals A general modeling framework for describing spatially structured population dynamics

2017 ◽  
Vol 8 (1) ◽  
pp. 493-508 ◽  
Author(s):  
Christine Sample ◽  
John M. Fryxell ◽  
Joanna A. Bieri ◽  
Paula Federico ◽  
Julia E. Earl ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Modeling Framework ◽  
Structured Population ◽  
Structured Population Dynamics ◽  
Spatially Structured Population

Evolution in a spatially structured population subject to rare epidemics

2001 ◽  
Vol 63 (4) ◽  
Author(s):  
Joshua E. S. Socolar ◽  
Shane Richards ◽  
William G. Wilson
Keyword(s):  
Structured Population ◽  
Spatially Structured Population

scholarly journals Complete Genome Sequence of Enterococcus Bacteriophage EFLK1

2015 ◽  
Vol 3 (6) ◽  
Author(s):  
Leron Khalifa ◽  
Shunit Coppenhagen-Glazer ◽  
Mor Shlezinger ◽  
Miriam Kott-Gutkowski ◽  
Omri Adini ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Therapeutic Use ◽  
Lytic Phage ◽  
Bacterial Strains ◽  
Highly Effective

We previously isolated EFDG1, a lytic phage against enterococci for therapeutic use. Nevertheless, EFDG1-resistant bacterial strains (EFDG1 r ) have evolved. EFLK1, a new highly effective phage against EFDG1 r strains, was isolated in this study. The genome of EFLK1 was fully sequenced, analyzed, and deposited in GenBank.

scholarly journals Fitness benefits of low infectivity in a spatially structured population of bacteriophages

2014 ◽  
Vol 281 (1774) ◽  
pp. 20132563 ◽  
Author(s):  
Pavitra Roychoudhury ◽  
Neelima Shrestha ◽  
Valorie R. Wiss ◽  
Stephen M. Krone
Keyword(s):  
Transmission Rate ◽  
Burst Size ◽  
Structured Populations ◽  
Host Cells ◽  
Structured Population ◽  
Spatially Structured Populations ◽  
Lysis Time ◽  
Evolution Experiment ◽  
Spatially Structured Population ◽  
And Diffusion

For a parasite evolving in a spatially structured environment, an evolutionarily advantageous strategy may be to reduce its transmission rate or infectivity. We demonstrate this empirically using bacteriophage (phage) from an evolution experiment where spatial structure was maintained over 550 phage generations on agar plates. We found that a single substitution in the major capsid protein led to slower adsorption of phage to host cells with no change in lysis time or burst size. Plaques formed by phage isolates containing this mutation were not only larger but also contained more phage per unit area. Using a spatially explicit, individual-based model, we showed that when there is a trade-off between adsorption and diffusion (i.e. less ‘sticky’ phage diffuse further), slow adsorption can maximize plaque size, plaque density and overall productivity. These findings suggest that less infective pathogens may have an advantage in spatially structured populations, even when well-mixed models predict that they will not.

scholarly journals Individual versus cluster recoveries within a spatially structured population

2006 ◽  
Vol 16 (1) ◽  
pp. 403-422 ◽  
Author(s):  
L. Belhadji ◽  
N. Lanchier
Keyword(s):  
Structured Population ◽  
Spatially Structured Population

scholarly journals Slightly beneficial genes are retained by evolving Horizontal Gene Transfer despite selfish elements

2020 ◽  
Author(s):  
B. van Dijk ◽  
P. Hogeweg ◽  
H.M. Doekes ◽  
N. Takeuchi
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Growth Rates ◽  
Selfish Genetic Elements ◽  
Structured Population ◽  
Rapid Changes ◽  
Spatially Structured Population ◽  
Fitness Benefits ◽  
Bacterial Growth Rates ◽  
Gene Sharing

AbstractHorizontal gene transfer (HGT) is a key component of bacterial evolution, which in concert with gene loss can result in rapid changes in gene content. While HGT can evidently aid bacteria to adapt to new environments, it also carries risks since bacteria may pick up selfish genetic elements (SGEs). Here, we use modeling to study how bacterial growth rates are affected by HGT of slightly beneficial genes, if bacteria can evolve HGT to improve their growth rates, and when HGT is evolutionarily maintained in light of harmful SGEs. We find that we can distinguish between four classes of slightly beneficial genes: indispensable, enrichable, rescuable, and unrescuable genes. Rescuable genes – genes that confer small fitness benefits and are lost from the population in the absence of HGT — can be collectively retained by a bacterial community that engages in HGT. While this ‘gene-sharing’ cannot evolve in well-mixed cultures, it does evolve in a spatially structured population such as a biofilm. Although HGT does indeed enable infection by harmful SGEs, HGT is nevertheless evolutionarily maintained by the hosts, explaining the stable coexistence and co-evolution of bacteria and SGEs.

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