Author(s)

Elsa-Rush Eyang-Assengone^1,2*, Carole Cassagne³, Roland Dieki^1,2, Jean Paul Akue¹, Jean Bernard Lekana-Douki^1,4,5, Stéphane Ranque^3,6

¹Centre Interdisciplinaire de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon.
²Unité de Recherches en Ecologie de la Santé (URES), Franceville, Gabon.
³IHU-Méditerranée Infection, Marseille, France.
⁴Unité Ecologie Evolution et Résistances Parasitaires (UNEEREP), Franceville, Gabon.
⁵Département de Parasitologie-Mycologie, Université des Sciences de la Santé (USS), Libreville, Gabon.
⁶Aix Marseille University, IRD, AP-HM, SSA, Vitrome, Marseille, France.

Mass spectrometry (MS) is a powerful tool for identifying bacteria and fungi. Several attempts have been made to apply the technique in clinical parasitology but not in filarial identification. The study shows that MALDI-TOF-MS is a promising tool to identify Loa loa microfilaria of patients from an endemic country. Loa loa microfilariae were isolated and purified from blood via a Percoll gradient. The microfilaria was separated into different groups from 1 microfilaria to 500 microfilaria specimens. Four extraction procedures were subsequently tested to determine the most adaptable procedure for the quality protein for MALDI-TOF MS analysis. A reference database of spectra was constructed and tested on a panel of 80 isolates. A blind test of 80 spectra was performed against the created library. Results showed that the best protocol for protein extraction used an equal volume of 70% formic acid 100% acetonitrile. Good resolution spectra were obtained at 400 microfilariae. The approach correctly identified all the patients. Ten spectra that were used to build a MS. The LSV obtained after comparison of the spectra with the MSP showed a good technical reproducibility ranged from 1.86 to 2.9, with a mean of 2.398 ± 0.046 and a good biological reproducibility with a mean of 2.13 [1.17 - 2.55]. MALDI-TOF MS is a promising approach, providing rapid and accurate identification of L. loa microfilaria.

Loiasis, Microfilariae, Parasite, Identification, Diagnostic

Eyang-Assengone, E.-R., Cassagne, C., Dieki, R., Akue, J.P., Lekana-Douki, J.B. and Ranque, S. (2025) Creation of the MALDI-TOF MS Database for Identification of Loa loa Microfilaria: Preliminary Study. Advances in Microbiology, 15, 371-385. doi: 10.4236/aim.2025.156025.