Leprosy is one among serious skin infection diseases present worldwide. Leprosy is associated with significant social stigma that renders the life of affected individuals difficult and isolated. Leprosy is caused by Mycobacterium leprae with a chronic granulomatous infection of the peripheral nerves along with the skin. The disease is characterized by damage of the peripheral nerves, mucous membranes, eyes and skin. Untreated skin especially on the face thickens because of dermal infiltration giving rise to the ‘leonine faces’. Skin is the primary organ affected in leprosy patients, though the role of skin microbiome in pathogenesis is not very well studied. One of the recent studies have shown that skin of leprosy patients harbors perturbed microbiota which grants inflammation and disease progression.
Researchers conducted a collaborative study in order to understand the lesional and non-lesional skin microbiota in leprosy patients. Different experimental techniques were used for conducting this study. DGGE is a molecular sequence dependent fingerprinting technique that allows characterization of the microbiota from large number of skin samples without pre-existing knowledge of its composition. In this study, nested PCR-DGGE and a comprehensive computational analysis for the microbial diversity exploration present in skin swab samples collected from LS and NLS sites was done. The overall objective of the study was to catalogue and compare the skin microbial communities present in healthy control with those in lesional skin (LS) and non-lesional skin (NLS) sites of Leprosy patients. According to the researchers, the results obtained from this study can potentially be used for generating preliminary hypotheses about interaction between disease causing microorganisms, microbial co-inhabitants and pathophysiology of the disease in leprosy patients.
A comprehensive analysis of 16S rRNA profiles was done, corresponding to skin samples from participants located in two geographical locations in India, Hyderabad and Miraj. Study participants were chosen from well-established leprosy research centers located in two geographically well-separated locations in India in order to understand if any variability occurs as a result of differences in food, climate and lifestyle. The genus Staphylococcus was one of the representative bacteria in healthy controls while it was underrepresented in skin microbiota of leprosy patients. Taxa affiliated to phyla Firmicutes and Proteobacteria were found in abundance in healthy controls and lesional skin, respectively.
While the NLS microbiota for LP from both Hyderabad and Miraj indicated the presence of similar microbiota with bacteria belonging to genus Canibacter, Corynebacterium, Cutibacterium, Janibacter, Moraxella and Staphylococcus, samples of LP from Miraj were observed to additionally harbour Bacillus, Methylobacterium, Microvirga, Paracoccus and Staphylococcus. Some of the important genera found in Hyderabad subjects were Canibacter, Corynebacterium, Cutibacterium, Janibacter, Moraxella and Staphylococcus while Miraj subjects had Bacillus, Methylobacterium, Microvirga, Paracoccus and Staphylococcus genera. Taxonomic analysis indicates presence of few taxa having distinct abundance trends between healthy control (HC) and leprosy patients (LP) : Acinetobacter, Corynebacterium, Kocuria, Micrococcus, Paracoccus, Propionibacterium, Staphlococcus were observed to be the most abundant common taxa in samples from both Hyderabad and Miraj.
Network analysis study reveals signature differences in microbial co-occurrence patterns in datasets corresponding to HC and LP. The skin lesions occurring on the lesional and non-lesional skin surface has analyzed some sort of abnormalities. The abnormalities were structured to undergo through experimental sites that are lesional and non-lesional sites, and understand the severity of the disease.
Observed diversity level changes, shifts in core microbiota, and community network structure support the evident dysbiosis in normal skin microbiota due to leprosy. Insights obtained indicate the need for exploring skin microbiota modulation as a potential therapeutic option for leprosy.
In order to understand the detailed results in this study please refer: https://www.nature.com/articles/s41598-020-80533-5