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Growth and Survival of Mesorhizobium loti Inside Acanthamoeba Enhanced Its Ability to Develop More Nodules on Lotus corniculatus.

Karaś MA, Turska-Szewczuk A, Trapska D, Urbanik-Sypniewska T - Microb. Ecol. (2015)

Bottom Line: Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased.The internalization of mesorhizobia was mediated by the mannose-dependent receptor.M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland, magdalena.karas@poczta.umcs.lublin.pl.

ABSTRACT
The importance of protozoa as environmental reservoirs of pathogens is well recognized, while their impact on survival and symbiotic properties of rhizobia has not been explored. The possible survival of free-living rhizobia inside amoebae could influence bacterial abundance in the rhizosphere of legume plants and the nodulation competitiveness of microsymbionts. Two well-characterized strains of Mesorhizobium: Mesorhizobium loti NZP2213 and Mesorhizobium huakuii symbiovar loti MAFF303099 were assayed for their growth ability within the Neff strain of Acanthamoeba castellanii. Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased. The latter strain was also able to survive prolonged co-incubation within amoebae and to self-release from the amoeba cell. The temperature 28 °C and PBS were established as optimal for the uptake of Mesorhizobium by amoebae. The internalization of mesorhizobia was mediated by the mannose-dependent receptor. M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

No MeSH data available.


Related in: MedlinePlus

Results of phagocytosis inhibitory assays performed with use of different exogenous sugars (Glc, Gal, Man; at a final concentration 100 mM in PBS) and genistein (a protein tyrosine kinase inhibitor). These experiments were performed in PBS medium at 28 °C for 4 h and bacteria internalized by amoeba without an inhibitory treatment were assumed as a control. The bars labelled with stars represent the percent of viable intra-amoebic bacteria, which are significantly different at p < 0.001, and the extended bars represent the standard deviation (n = 3). All p values have been corrected for multiple comparisons by multiplying the calculated p value by the number of comparisons made (Tukey’s test through GraphPad Prism 6.0 software)
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Fig4: Results of phagocytosis inhibitory assays performed with use of different exogenous sugars (Glc, Gal, Man; at a final concentration 100 mM in PBS) and genistein (a protein tyrosine kinase inhibitor). These experiments were performed in PBS medium at 28 °C for 4 h and bacteria internalized by amoeba without an inhibitory treatment were assumed as a control. The bars labelled with stars represent the percent of viable intra-amoebic bacteria, which are significantly different at p < 0.001, and the extended bars represent the standard deviation (n = 3). All p values have been corrected for multiple comparisons by multiplying the calculated p value by the number of comparisons made (Tukey’s test through GraphPad Prism 6.0 software)

Mentions: Since only NZP2213 was able to survive inside the amoebae, the strain was chosen for these studies. The most efficient conditions established for the invasive assay (28 °C, PBS medium and 4-h co-incubation) were applied. Our findings demonstrated that the exposure of amoebae to D-mannose at a 100-mM concentration completely reduced the attachment of bacteria, which suggests involvement of mannose-binding lectin in the uptake of bacteria by amoeba (Fig. 4). The pretreatment of A. castellanii with D-galactose reduced by half the effect of the bacterial uptake when compared to the amount of bacteria recovered from the untreated amoebae (Fig. 4). In turn, the pretreatment of A. castellanii with D-glucose exerted a very weak inhibitory effect on bacterial attachment (Fig. 4).Fig. 4


Growth and Survival of Mesorhizobium loti Inside Acanthamoeba Enhanced Its Ability to Develop More Nodules on Lotus corniculatus.

Karaś MA, Turska-Szewczuk A, Trapska D, Urbanik-Sypniewska T - Microb. Ecol. (2015)

Results of phagocytosis inhibitory assays performed with use of different exogenous sugars (Glc, Gal, Man; at a final concentration 100 mM in PBS) and genistein (a protein tyrosine kinase inhibitor). These experiments were performed in PBS medium at 28 °C for 4 h and bacteria internalized by amoeba without an inhibitory treatment were assumed as a control. The bars labelled with stars represent the percent of viable intra-amoebic bacteria, which are significantly different at p < 0.001, and the extended bars represent the standard deviation (n = 3). All p values have been corrected for multiple comparisons by multiplying the calculated p value by the number of comparisons made (Tukey’s test through GraphPad Prism 6.0 software)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4494150&req=5

Fig4: Results of phagocytosis inhibitory assays performed with use of different exogenous sugars (Glc, Gal, Man; at a final concentration 100 mM in PBS) and genistein (a protein tyrosine kinase inhibitor). These experiments were performed in PBS medium at 28 °C for 4 h and bacteria internalized by amoeba without an inhibitory treatment were assumed as a control. The bars labelled with stars represent the percent of viable intra-amoebic bacteria, which are significantly different at p < 0.001, and the extended bars represent the standard deviation (n = 3). All p values have been corrected for multiple comparisons by multiplying the calculated p value by the number of comparisons made (Tukey’s test through GraphPad Prism 6.0 software)
Mentions: Since only NZP2213 was able to survive inside the amoebae, the strain was chosen for these studies. The most efficient conditions established for the invasive assay (28 °C, PBS medium and 4-h co-incubation) were applied. Our findings demonstrated that the exposure of amoebae to D-mannose at a 100-mM concentration completely reduced the attachment of bacteria, which suggests involvement of mannose-binding lectin in the uptake of bacteria by amoeba (Fig. 4). The pretreatment of A. castellanii with D-galactose reduced by half the effect of the bacterial uptake when compared to the amount of bacteria recovered from the untreated amoebae (Fig. 4). In turn, the pretreatment of A. castellanii with D-glucose exerted a very weak inhibitory effect on bacterial attachment (Fig. 4).Fig. 4

Bottom Line: Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased.The internalization of mesorhizobia was mediated by the mannose-dependent receptor.M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland, magdalena.karas@poczta.umcs.lublin.pl.

ABSTRACT
The importance of protozoa as environmental reservoirs of pathogens is well recognized, while their impact on survival and symbiotic properties of rhizobia has not been explored. The possible survival of free-living rhizobia inside amoebae could influence bacterial abundance in the rhizosphere of legume plants and the nodulation competitiveness of microsymbionts. Two well-characterized strains of Mesorhizobium: Mesorhizobium loti NZP2213 and Mesorhizobium huakuii symbiovar loti MAFF303099 were assayed for their growth ability within the Neff strain of Acanthamoeba castellanii. Although the association ability and the initial uptake rate of both strains were similar, recovery of viable M. huakuii MAFF303099 after 4 h postinfection decreased markedly and that of M. loti NZP2213 increased. The latter strain was also able to survive prolonged co-incubation within amoebae and to self-release from the amoeba cell. The temperature 28 °C and PBS were established as optimal for the uptake of Mesorhizobium by amoebae. The internalization of mesorhizobia was mediated by the mannose-dependent receptor. M. loti NZP2213 bacteria released from amoebae developed 1.5 times more nodules on Lotus corniculatus than bacteria cultivated in an amoebae-free medium.

No MeSH data available.


Related in: MedlinePlus