Characterization of Leishmania Ulcers Microbiota Using Next Generation Sequencing: Leishmania Ulcers Microbiota

Abstract

* Correspondence: Biochemistry & Molecular Biology Department, Faculty of Medicine, Al-Quds University, Abu Deis, Palestine. © copy rights 2021: All materials in this article are protected permission requests should be addressed to Al-Quds University. www. alquds.edu 1 Biochemistry and Molecular Biology Department-Faculty of Medicine, Al-Quds University, Abu Deis, Palestine 2Leishmanises Research Unit, Jericho, Palestine, 3Arab American University, Jenin, Palestine 4Al-Quds Nutrition and Health Research Institute, Faculty of Medicine, Al-Quds University, Palestine The human skin microbiome is a major source of bacteria in cutaneous leishmaniasis (CL) ulcers following the fall of the crust and the subsequent formation of a shallow depression in the epidermis and dermis of the skin. As a result, secondary bacterial infections are frequently observed which impair the healing process. Our study aimed to investigate the bacterial communities in CL lesions using next-generation sequencing. A total of 298 patients (178 males and 120 females; the median age of 17) presenting ulcerated skin lesions suspected with CL were included in this study. CL was confirmed in 153 (51%) cases by ITS1-PCR and/ or microscopy. Based on bacterial 16S rRNA-PCR, 92 samples were positive for the presence of bacteria, while 206 samples were negative and excluded from the microbiome study. A total of 925 Operational Taxonomic Units (OTUs) were identified and assigned to 215 genera. Despite an insignificant di!erence in the microbiome composition between CL and non-CL lesions, the phylum level analysis revealed that Actinobacteria was significantly higher in CL ulcers while Proteobacteria was significantly higher in non-CL ulcers (X2, P=0.039). The relative abundance of the most commonly encountered skin pathogens i. e E. coli, Pseudomonas aeruginosa, Enterobacter, Enterococcus and Acinetobacter species were significantly higher in non-CL ulcers (X2, P<0.05) compared to Staphylococcus aureus and Proteus mirabilis which was higher in CL ulcers (P<0.05). Our data showed that bacterial communities did not cluster according to the Leishmania infection. Nonetheless, bacterial diversity was lower in CL compared to non-CL lesions. Presence of pathogenic bacteria in CL lesions such as S. aureus might exacerbate lesions, hinder diagnosis, and delay healing.