Adenovirus masquerading as microsporidia

Area of Science:

• Medical Microbiology
• Virology
• Infectious Diseases

Background:

• Enterocytozoon bieneusi is an opportunistic pathogen causing chronic diarrhea in immunocompromised individuals, particularly those with acquired immunodeficiency syndrome (AIDS).
• Current diagnosis of E. bieneusi infection necessitates invasive procedures like duodenal biopsy and time-consuming electron microscopy, highlighting the need for improved diagnostic methods.

Purpose of the Study:

• To investigate the feasibility of establishing an in vitro culture system for Enterocytozoon bieneusi using mammalian cell cultures.
• To identify potential challenges or confounding factors in culturing E. bieneusi from clinical samples.

Main Methods:

• Mammalian cell cultures were inoculated with duodenal aspirates and/or biopsy specimens from two patients with suspected E. bieneusi infection.
• Light microscopy and transmission electron microscopy were employed to examine the cultured cells for the presence of microsporidia.
• Viral identification was performed on the cocultured organisms.

Main Results:

• An inadvertent coculture of adenovirus (identified as adenovirus type 8) alongside E. bieneusi was established.
• Light microscopy initially suggested the presence of microsporidia in adenovirus-infected cells, but electron microscopy revealed few microsporidia and numerous adenovirus-infected cells.
• Adenovirus type 8 infection appeared to inhibit the proliferation of E. bieneusi and led to the destruction of the cell cultures.

Conclusions:

• Adenovirus type 8 coinfection can interfere with the in vitro culture of Enterocytozoon bieneusi.
• The presence of adenovirus may mimic or mask microsporidial infections in cell cultures, posing a diagnostic challenge.
• Further research is needed to understand the interaction between adenovirus and E. bieneusi in cell culture and its implications for diagnosis.