Fig 1.
Representative confocal laser scanning microscopy images of nematodes harboring Legionella pneumophila KV02.
(A) Diploscapter coronatus. (B) Diploscapter pachys. (C) Plectus similis. (D) Plectus sp. Nematodes harbor L. pneumophila KV02 (mCherry, red) in the stoma (Plectus sp.), terminal bulb (D. coronatus), cardia (D. coronatus), intestine (D. coronatus, P. similis), and rectum (D. coronatus, D. pachys). Number of investigated individuals (n), number of individuals that harbored L. pneumophila KV02 (KV02) and number of individuals without L. pneumophila KV02 (none) after incubation for 24 h and 96 h are shown for each nematode species.
Fig 2.
Bacterial load of the digestive system of nematodes after incubation with Legionella pneumophila KV02.
Bacterial load as measured by mean fluorescence intensity (MFI: mean ± SEM Ind.-1). Nematodes were incubated with L. pneumophila KV02 (mCherry, red) for 24 h and 96 h. Compared were the mouth cavity (stoma), the oesophagus (pharynx, terminal bulb, cardia), and the gut (intestine, rectum). Bars with no or the same letters are not statistically different according to Dunn’s post hoc test (p < 0.05).
Fig 3.
Presence of mCherry-labeled Legionella pneumophila KV02 in the digestive system of nematodes.
Diploscapter coronatus (plain) and Plectus similis (dots) were incubated together in the same biofilm microcosm for 24 h and 96 h. Number of investigated individuals (n), number of individuals that harbored L. pneumophila KV02 (KV02) and number of individuals without bacteria are shown for each nematode species. The bacterial load is measured as mean fluorescence intensity (MFI: mean ± SEM Ind.-1). Statistical differences according to the Mann-Whitney U test with * and ** at p < 0.05 and p < 0.01, respectively.
Fig 4.
Legionella pneumophila KV02 and Escherichia coli DH10β in the digestive system of Plectus similis.
L. pneumophila KV02 (mCherry, red), E. coli DH10β (GFP, green) and P. similis were incubated together for 24 h in a biofilm model. (A) Stoma. (B) Pharynx. (C) Intestine. Confocal laser scanning microscopy images show the distribution of L. pneumophila KV02 (left) and E. coli DH10β (middle) separately and in merged images (right).
Fig 5.
Presence of mCherry-labeled Legionella pneumophila KV02 and GFP-labeled Escherichia coli DH10β in nematodes.
L. pneumophila KV02 (red), E. coli DH10β (gray) and nematodes were incubated together for 24 h in a biofilm model. Number of investigated individuals (n), number of individuals that harbored L. pneumophila KV02 (KV02) or E. coli DH10β (DH10β) and number of individuals without bacteria are shown for each nematode species. The bacterial load is measured as mean fluorescence intensity (MFI: mean ± SEM Ind.-1). Bars with no or the same letters are not statistically different according to Dunn’s post hoc test (p < 0.05).
Fig 6.
Presence of mCherry-labeled Legionella pneumophila KV02 and GFP-labeled E. coli DH10β in nematodes.
L. pneumophila KV02 (red), E. coli DH10β (gray) and the nematode species Diploscapter coronatus (plain) and Plectus similis (dots) were incubated together in the same biofilm microcosm for 24 h and 96 h. Number of investigated individuals (n), number of individuals that harbored L. pneumophila KV02 (KV02) or E. coli DH10β (DH10β) and number of individuals without bacteria are shown for each nematode species. The bacterial load is measured as mean fluorescence intensity (MFI: mean ± SEM Ind.-1). Statistical differences according to the Mann-Whitney U test with * and ** at p < 0.05 and p < 0.01, respectively.