Background: A common characteristic of Trichuris spp. infections in humans and animals is a low to varied efficacy of single-dose benzimidazoles, used in mass drug administration programmes against human trichuriasis. The bacillary band, a specialised morphological structure of Trichuris spp., as well as the unique partly intra- and extracellular habitat of adult Trichuris spp., may be involved in restricted drug absorption, resulting in a low drug accumulation. However, the function of the bacillary band is still unknown.
Methodology: We studied whether adult worms of T. muris were dependent on glucose and/or amino acids for survival in vitro and if the bacillary band has an absorptive function. The viability of the worms was evaluated microscopically using a motility scale from 0 - 3, and by measuring emission in response to metabolic activity utilizing the colorimetric assay Alamar Blue. The absorptive function of the bacillary band was explored using a fluorescent glucose analogue (6-NBDG) detected in the living worms by confocal microscopy. To exclude oral ingestion of 6-NBDG, the oral cavity of T. muris worms was sealed.
Principal Findings: Adult worms of T. muris incubated in media devoid of glucose were immotile after 17 hours incubation and generated an emission signal similar to controls (RPMI media without worms). The fluorescent glucose analogue was detected in the pores of the bacillary band and accumulated inside the worms, primarily within the stichocytes in living worms with and without a sealed oral cavity.
Conclusions/Significance: The whipworm T. muris is dependent on glucose for survival in vitro, and the bacillary band has an absorptive function in relation to the glucose analogue 6-NBDG which accumulates within the stichocytes of the worms. This new insight into the absorptive function of the bacillary band may encourage for further explorations of the bacillary band in relation to anthelmintics.