Bacteria-like endosymbionts in Blastocystis sp

Area of Science:

• Microbiology
• Parasitology
• Cell Biology

Background:

• Blastocystis sp. is a common intestinal protist found in various hosts.
• Endosymbionts within eukaryotic microorganisms are crucial for understanding host-microbe interactions.
• The intracellular presence of bacteria within Blastocystis sp. has been previously reported but requires further characterization.

Purpose of the Study:

• To investigate the ultrastructure and intracellular location of bacteria-like endosymbionts in Blastocystis sp. from different hosts.
• To determine if the observed endosymbionts represent distinct species based on morphological and localization differences.

Main Methods:

• Transmission electron microscopy was used to examine the ultrastructure of Blastocystis sp. isolates.
• Faecal samples from ducks and monkeys were analyzed for the presence of Blastocystis sp.
• Intracellular localization of endosymbionts within Blastocystis sp. cells was determined.

Main Results:

• Bacteria-like endosymbionts were observed in vacuolar cells and cysts of Blastocystis sp. from both duck and monkey origins.
• Ultrastructurally, the endosymbionts resembled Gram-negative bacilli.
• Endosymbionts were found within the nucleus of Blastocystis sp. from ducks and in the cytoplasm of those from monkeys.

Conclusions:

• The endosymbionts found in duck and monkey Blastocystis sp. exhibit distinct intracellular locations and probable morphological differences.
• These findings suggest the presence of at least two distinct bacterial endosymbiont species associated with Blastocystis sp.
• Further molecular and comparative studies are warranted to confirm the species designation of these endosymbionts.