Genetic identification of intestinal microsporidia species in immunocompromised patients in Tunisia

Area of Science:

• Medical Parasitology
• Molecular Diagnostics
• Infectious Diseases

Background:

• Intestinal microsporidiosis is an opportunistic infection common in immunocompromised individuals.
• Diagnosis can be challenging with conventional microscopy, necessitating advanced molecular techniques.
• Limited data exists on microsporidiosis prevalence in Tunisia, particularly in specific patient groups.

Purpose of the Study:

• To systematically screen immunocompromised patients for intestinal microsporidiosis using microscopy and PCR.
• To identify the specific microsporidia species present in the Tunisian patient cohort.
• To evaluate the utility of molecular tools for diagnosing microsporidiosis in this population.

Main Methods:

• Stool samples from 86 immunocompromised patients (HIV-infected and hematologic malignancy patients) were analyzed.
• Microscopic examination and polymerase chain reaction (PCR) with universal primers were employed.
• Species-specific primers and sequencing were used for definitive identification of microsporidia.

Main Results:

• Nine samples (10.5%) tested positive by PCR, with six from HIV-infected patients and three from patients with myeloma.
• Microscopy confirmed five cases, all in HIV-infected patients.
• Three microsporidia species were identified for the first time in Tunisia: Enterocytozoon bieneusi, Encephalitozoon intestinalis, and Encephalitozoon hellem.

Conclusions:

• PCR is a more sensitive diagnostic tool for intestinal microsporidiosis than microscopy in immunocompromised patients.
• The identification of multiple microsporidia species underscores the importance of molecular diagnostics in Tunisia.
• Wider implementation of these molecular tools can improve the diagnosis and management of microsporidiosis in immunocompromised individuals.