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Drosophila melanogaster as a model host for the Burkholderia cepacia complex.

Castonguay-Vanier J, Vial L, Tremblay J, Déziel E - PLoS ONE (2010)

Bottom Line: Colonization with bacterial species from the Burkholderia cepacia complex (Bcc) is associated with fast health decline among individuals with cystic fibrosis.While the feeding method proved unsuccessful at killing the flies, the pricking technique did generate mortality within the populations.Moreover, CI results indicate that this method is more sensitive than mortality tests.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Recherche Scientifique-Institut Armand Frappier, Laval, Canada.

ABSTRACT

Background: Colonization with bacterial species from the Burkholderia cepacia complex (Bcc) is associated with fast health decline among individuals with cystic fibrosis. In order to investigate the virulence of the Bcc, several alternative infection models have been developed. To this end, the fruit fly is increasingly used as surrogate host, and its validity to enhance our understanding of host-pathogen relationships has been demonstrated with a variety of microorganisms. Moreover, its relevance as a suitable alternative to mammalian hosts has been confirmed with vertebrate organisms.

Methodology/principal findings: The aim of this study was to establish Drosophila melanogaster as a surrogate host for species from the Bcc. While the feeding method proved unsuccessful at killing the flies, the pricking technique did generate mortality within the populations. Results obtained with the fruit fly model are comparable with results obtained using mammalian infection models. Furthermore, validity of the Drosophila infection model was confirmed with B. cenocepacia K56-2 mutants known to be less virulent in murine hosts or in other alternative models. Competitive index (CI) analyses were also performed using the fruit fly as host. Results of CI experiments agree with those obtained with mammalian models.

Conclusions/significance: We conclude that Drosophila is a useful alternative infection model for Bcc and that fly pricking assays and competition indices are two complementary methods for virulence testing. Moreover, CI results indicate that this method is more sensitive than mortality tests.

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Survival curves for D. melanogaster infected with B. cenocepacia strains.Pricking assays were performed with a minimum of 30 flies for each strain. Statistical significance (Log-rank analysis (Mantel-Cox)) between survival curves is shown with *p<0.05 and ***p<0.0005.
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pone-0011467-g002: Survival curves for D. melanogaster infected with B. cenocepacia strains.Pricking assays were performed with a minimum of 30 flies for each strain. Statistical significance (Log-rank analysis (Mantel-Cox)) between survival curves is shown with *p<0.05 and ***p<0.0005.

Mentions: Pricking experiments uncovered differences in terms of virulence between the Bcc species and strains, allowing discrimination between strains of one particular genomovar but also between Bcc genomovars. As a demonstration, flies were infected with five different wild-type strains of B. cenocepacia (genomovar III), revealing variability in infectious capacity between strains of the same Bcc genomovar (Figure 2). Among these strains, we tested K56-2 and J2315 two closely related strains belonging to the epidemic ET-12 lineage [34]. We observed that J2315 is less virulent than K56-2 in the D. melanogaster model, which is in agreement with recent data from Uehlinger and colleagues who reported that J2315 is also less virulent than K56-2 in two other alternative models, G. mellonella and C. elegans[35]. While strain LMG 18830 (CEP511) exhibits moderate virulence in the Drosophila, mouse and wax moth models, it produces very different infection outcomes in alfalfa (pathogenic) and C. elegans (non lethal) [18], [19].


Drosophila melanogaster as a model host for the Burkholderia cepacia complex.

Castonguay-Vanier J, Vial L, Tremblay J, Déziel E - PLoS ONE (2010)

Survival curves for D. melanogaster infected with B. cenocepacia strains.Pricking assays were performed with a minimum of 30 flies for each strain. Statistical significance (Log-rank analysis (Mantel-Cox)) between survival curves is shown with *p<0.05 and ***p<0.0005.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2902503&req=5

pone-0011467-g002: Survival curves for D. melanogaster infected with B. cenocepacia strains.Pricking assays were performed with a minimum of 30 flies for each strain. Statistical significance (Log-rank analysis (Mantel-Cox)) between survival curves is shown with *p<0.05 and ***p<0.0005.
Mentions: Pricking experiments uncovered differences in terms of virulence between the Bcc species and strains, allowing discrimination between strains of one particular genomovar but also between Bcc genomovars. As a demonstration, flies were infected with five different wild-type strains of B. cenocepacia (genomovar III), revealing variability in infectious capacity between strains of the same Bcc genomovar (Figure 2). Among these strains, we tested K56-2 and J2315 two closely related strains belonging to the epidemic ET-12 lineage [34]. We observed that J2315 is less virulent than K56-2 in the D. melanogaster model, which is in agreement with recent data from Uehlinger and colleagues who reported that J2315 is also less virulent than K56-2 in two other alternative models, G. mellonella and C. elegans[35]. While strain LMG 18830 (CEP511) exhibits moderate virulence in the Drosophila, mouse and wax moth models, it produces very different infection outcomes in alfalfa (pathogenic) and C. elegans (non lethal) [18], [19].

Bottom Line: Colonization with bacterial species from the Burkholderia cepacia complex (Bcc) is associated with fast health decline among individuals with cystic fibrosis.While the feeding method proved unsuccessful at killing the flies, the pricking technique did generate mortality within the populations.Moreover, CI results indicate that this method is more sensitive than mortality tests.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Recherche Scientifique-Institut Armand Frappier, Laval, Canada.

ABSTRACT

Background: Colonization with bacterial species from the Burkholderia cepacia complex (Bcc) is associated with fast health decline among individuals with cystic fibrosis. In order to investigate the virulence of the Bcc, several alternative infection models have been developed. To this end, the fruit fly is increasingly used as surrogate host, and its validity to enhance our understanding of host-pathogen relationships has been demonstrated with a variety of microorganisms. Moreover, its relevance as a suitable alternative to mammalian hosts has been confirmed with vertebrate organisms.

Methodology/principal findings: The aim of this study was to establish Drosophila melanogaster as a surrogate host for species from the Bcc. While the feeding method proved unsuccessful at killing the flies, the pricking technique did generate mortality within the populations. Results obtained with the fruit fly model are comparable with results obtained using mammalian infection models. Furthermore, validity of the Drosophila infection model was confirmed with B. cenocepacia K56-2 mutants known to be less virulent in murine hosts or in other alternative models. Competitive index (CI) analyses were also performed using the fruit fly as host. Results of CI experiments agree with those obtained with mammalian models.

Conclusions/significance: We conclude that Drosophila is a useful alternative infection model for Bcc and that fly pricking assays and competition indices are two complementary methods for virulence testing. Moreover, CI results indicate that this method is more sensitive than mortality tests.

Show MeSH
Related in: MedlinePlus