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The Agr communication system provides a benefit to the populations of Listeria monocytogenes in soil.

Vivant AL, Garmyn D, Gal L, Piveteau P - Front Cell Infect Microbiol (2014)

Bottom Line: Alteration of the ability to communicate, either by deletion of the gene coding the response regulator AgrA (response-negative mutant) or the signal pro-peptide AgrD (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the Agr system of L. monocytogenes was involved to face the complex soil biotic environment.These results showed that the ability to respond to Agr communication provided a benefit to listerial cells to compete.These results might also indicate that in soil, the Agr system controls private goods rather than public goods.

View Article: PubMed Central - PubMed

Affiliation: Unités Mixtes de Recherche1347 Agroécologie, Université de Bourgogne Dijon, France ; Institut National de la Recherche Agronomique, Unités Mixtes de Recherche1347 Agroécologie Dijon, France.

ABSTRACT
In this study, we investigated whether the Agr communication system of the pathogenic bacterium Listeria monocytogenes was involved in adaptation and competitiveness in soil. Alteration of the ability to communicate, either by deletion of the gene coding the response regulator AgrA (response-negative mutant) or the signal pro-peptide AgrD (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the Agr system of L. monocytogenes was involved to face the complex soil biotic environment. This was confirmed by a set of co-incubation experiments. The fitness of the response-negative mutant was lower either in the presence or absence of the parental strain but the fitness of the signal-negative mutant depended on the strain with which it was co-incubated. The survival of the signal-negative mutant was higher when co-cultured with the parental strain than when co-cultured with the response-negative mutant. These results showed that the ability to respond to Agr communication provided a benefit to listerial cells to compete. These results might also indicate that in soil, the Agr system controls private goods rather than public goods.

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Growth kinetics of L. monocytogenes (◼) parental strain, (⚫) signal- and (○) response-negative mutants in sterilized soil microcosms. Error bars represent the standard deviation from three replicate samples value.
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Figure 1: Growth kinetics of L. monocytogenes (◼) parental strain, (⚫) signal- and (○) response-negative mutants in sterilized soil microcosms. Error bars represent the standard deviation from three replicate samples value.

Mentions: In sterilized soil microcosms, the population of the parental strain L. monocytogenes L9 increased of over 2 log within the first 2 days of incubation and the population remained stable until the end of the experiment (Figure 1). Inactivation of the Agr system did not affect the dynamics of the mutants' population and no significant differences were observed between growth profiles of the parental strain, the signal-negative ΔagrD mutant and the response-negative ΔagrA mutant. Similar results were collected during growth in sterilized soil extracts (data not shown). These results confirm previous reports on the ability of L. monocytogenes to multiply in sterilized soil (Dowe et al., 1997; Moshtaghi et al., 2009; McLaughlin et al., 2011; Piveteau et al., 2011). Moreover, our results suggest that the ability to produce AIP and to respond to the signal is not indispensable for growth of L. monocytogenes in this specific environment.


The Agr communication system provides a benefit to the populations of Listeria monocytogenes in soil.

Vivant AL, Garmyn D, Gal L, Piveteau P - Front Cell Infect Microbiol (2014)

Growth kinetics of L. monocytogenes (◼) parental strain, (⚫) signal- and (○) response-negative mutants in sterilized soil microcosms. Error bars represent the standard deviation from three replicate samples value.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4222237&req=5

Figure 1: Growth kinetics of L. monocytogenes (◼) parental strain, (⚫) signal- and (○) response-negative mutants in sterilized soil microcosms. Error bars represent the standard deviation from three replicate samples value.
Mentions: In sterilized soil microcosms, the population of the parental strain L. monocytogenes L9 increased of over 2 log within the first 2 days of incubation and the population remained stable until the end of the experiment (Figure 1). Inactivation of the Agr system did not affect the dynamics of the mutants' population and no significant differences were observed between growth profiles of the parental strain, the signal-negative ΔagrD mutant and the response-negative ΔagrA mutant. Similar results were collected during growth in sterilized soil extracts (data not shown). These results confirm previous reports on the ability of L. monocytogenes to multiply in sterilized soil (Dowe et al., 1997; Moshtaghi et al., 2009; McLaughlin et al., 2011; Piveteau et al., 2011). Moreover, our results suggest that the ability to produce AIP and to respond to the signal is not indispensable for growth of L. monocytogenes in this specific environment.

Bottom Line: Alteration of the ability to communicate, either by deletion of the gene coding the response regulator AgrA (response-negative mutant) or the signal pro-peptide AgrD (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the Agr system of L. monocytogenes was involved to face the complex soil biotic environment.These results showed that the ability to respond to Agr communication provided a benefit to listerial cells to compete.These results might also indicate that in soil, the Agr system controls private goods rather than public goods.

View Article: PubMed Central - PubMed

Affiliation: Unités Mixtes de Recherche1347 Agroécologie, Université de Bourgogne Dijon, France ; Institut National de la Recherche Agronomique, Unités Mixtes de Recherche1347 Agroécologie Dijon, France.

ABSTRACT
In this study, we investigated whether the Agr communication system of the pathogenic bacterium Listeria monocytogenes was involved in adaptation and competitiveness in soil. Alteration of the ability to communicate, either by deletion of the gene coding the response regulator AgrA (response-negative mutant) or the signal pro-peptide AgrD (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the Agr system of L. monocytogenes was involved to face the complex soil biotic environment. This was confirmed by a set of co-incubation experiments. The fitness of the response-negative mutant was lower either in the presence or absence of the parental strain but the fitness of the signal-negative mutant depended on the strain with which it was co-incubated. The survival of the signal-negative mutant was higher when co-cultured with the parental strain than when co-cultured with the response-negative mutant. These results showed that the ability to respond to Agr communication provided a benefit to listerial cells to compete. These results might also indicate that in soil, the Agr system controls private goods rather than public goods.

Show MeSH
Related in: MedlinePlus