The Haptomonad Stage of Crithidia acanthocephali in Apis mellifera Hindgut

Crithidia acanthocephali is a trypanosomatid species that was initially described in the digestive tract of Hemiptera. However, this parasite was recently detected in honey bee colonies in Spain, raising the question as to whether bees can act as true hosts for this species. To address this issue, worker bees were experimentally infected with choanomastigotes from the early stationary growth phase and after 12 days, their hindgut was extracted for analysis by light microscopy and TEM. Although no cellular lesions were observed in the honey bee's tissue, trypanosomatids had differentiated and adopted a haptomonad morphology, transforming their flagella into an attachment pad. This structure allows the protozoa to remain attached to the gut walls via hemidesmosomes-such as junctions. The impact of this species on honey bee health, as well as the pathogenic mechanisms involved, remains unknown. Nevertheless, these results suggest that insect trypanosomatids may have a broader range of hosts than initially thought.

Automated summary

The trypanosomatid species Crithidia acanthocephali, initially found in the digestive tract of Hemiptera, was recently detected in honey bee colonies in Spain, leading to questions about bees as potential hosts for this parasite. Experimental infection of worker bees with choanomastigotes resulted in the differentiation of the parasites and the adoption of a haptomonad morphology, attaching to the gut walls via hemidesmosomes-like junctions. These findings suggest that insect trypanosomatids may have a wider range of hosts than previously thought.