Fig 1.
M. leprae loss viability in mosquitoes.
The number of life M. leprae was determined by M. leprae 16SrRNA levels in Aedes aegypti (A) and Culex quinquefasciatus (B) abdomen (spheres) and thorax (squares). All mosquitoes were dissected 2 hours and 20 days after blood meal. Line represents median and each point is a pool of 10 mosquitoes, obtained in three independent experiments. Non-infected controls did not show amplification of the targets (CT>39).
Fig 2.
The kissing bug Rhodnius prolixus is able to maintain M. leprae viability inside its digestive tract after infection.
M. leprae viability was determined by the persistence of 16Sr RNA at the different digestive compartments of artificially infected adult Rhodnius prolixus: anterior midgut (spheres), posterior midgut (squares) and hindgut (triangles), just after blood meal (2h) and after total blood meal digestion (20 days), infected with the pathogen. As we can see, the hindgut was the only compartment where the level of living M. leprae increases after 20 days of infection. Scatter plot showing mean and SEM of four independent experiments, each point represent five insects group. *** means p < 0.001 (2h x 20 days, for each group of sample). Non-infected controls did not present amplification of the targets.
Fig 3.
M. leprae rarely infects digestive epithelial cells of Rhonius prolixus.
Immunohistofluorescence of tissue section from anterior midgut (A-C), posterior midgut (D-E) and hindgut (G-I) from infected and non-infected kissing bugs 2h and 20 days after infection. M. leprae was evidenced in red by IgG-LAM staining, and epithelial cells nuclei in blue by DAPI staining. Asterisks mark the luminal regions in all images, and arrows point to intracellular M. leprae. Images are representative of at least 15 fields, captured from six different insects, infected in three different experiments. Scale bar means 20μm.
Fig 4.
M. leprae reaches Rhodnius prolixus feces 20 days after infection.
Rhodnius prolixus were allowed to feed rabbit blood containing (A-B) or not (C-D) 107 PKH26-M. leprae / mL. During the next non-infected blood meal (20 days after infection), feces from groups of ten insects were collected in a sterile tube and analyzed by fluorescence microscopy (B and D). Stained M. leprae was identified only in the infected insects (A-B), allowing its counting. Images are representative of six pools of feces, where at least five fields were analyzed. Scale bar indicates 20μm.
Table 1.
Numbers of M. leprae recovered from mice footpads after a six month infection with 104 bacillus isolated from Rhodnius prolixus feces that received an infectious blood meal.