Heterogeneity among Mycobacterium ulcerans from French Guiana Revealed by Multilocus Variable Number Tandem Repeat Analysis (MLVA)

Abstract

Buruli ulcer is an emerging and neglected tropical disease caused by Mycobacterium ulcerans. Few cases have been reported so far in the Americas. With 250 cases reported since 1969, French Guiana is the only Buruli ulcer endemic area in the continent. Thus far, no genetic diversity studies of strains of M. ulcerans from French Guiana have been reported. Our goal in the present study was to examine the genetic diversity of M. ulcerans strains in this region by using the Multilocus Variable Number Tandem Repeat Analysis (MLVA) approach. A total of 23 DNA samples were purified from ulcer biopsies or derived from pure cultures. MVLA was used in the study of six previously-described Variable Number of Tandem Repeat (VNTR) markers. A total of three allelic combinations were characterized in our study: genotype I which has been described previously, genotype III which is very similar to genotype I, and genotype II which has distinctly different characteristics in comparison with the other two genotypes. This high degree of genetic diversity appears to be uncommon for M. ulcerans. Further research based on complete genome sequencing of strains belonging to genotypes I and II is in progress and should lead soon to a better understanding of genetic specificities of M. ulcerans strains from French Guiana.

Mycobacterium ulcerans Infection in French Guiana; Current State of Knowledge

“…In the phylogenomic analysis it clustered with fish pathogens belonging to the sublineage 1 of the ancestral lineage, as defined by Doig et al [8]. A recent study based on Multilocus Variable Number Tandem Repeat Analysis (MLVA) looked at the genetic diversity of M. ulcerans strains isolated from BU patients from French Guiana between 1994 and 2013 [11]. A total of 23 DNA samples obtained from 23 patients were purified from ulcer biopsies or derived from cultures.…”

Epidemiology and disease burden of Buruli ulcer: a review

“…Published reports on the occurrence of M. ulcerans infections are limited [41][42][43][44]47,48 and only very few cases of BU have been reported to the WHO. While fewer than ten cases per country have been confirmed in Suriname, Mexico, Peru, and Brazil in the past 50 years, 42 .250 cases have been notified between 1969 and 2014 in French Guiana, which borders Brazil to the east and south, and Suriname to the west.…”

“…Recently, M. ulcerans DNA (IS2404 and the ketoreductase B domain gene) has been detected in specimens from three of 23 different freshwater bodies sampled in French Guiana, indicative for the presence of this species in the environment. 43 The recent observation of genetic heterogeneity among 23 isolates from patients living along the coastline of French Guiana as revealed by Multilocus Variable Number Tandem Repeat Analysis 44 is uncommon for M. ulcerans, which usually shows very limited genetic diversity within particular endemic areas. 14,45,46 While two of the genotypes detected in French Guiana showed high similarity, one had distinctly different characteristics and shared more sequence similarity with the M. ulcerans ecovar liflandii.…”

“…No geographical clustering of the genotypes was observed. 44 While French Guiana is the only country in the Americas actively reporting BU cases to the WHO, 13 sporadic infections have been reported from other American countries dating back several years.…”

Buruli ulcers in a Spanish aid worker after a stay in Peru

“…MLVA was performed using six previously described variable number tandem repeat (VNTR) markers: VNTR18 and VNTR19 , mycobacterial interspersed repetitive units MIRU5 and MIRU33 (Stragier et al, 2005), ST1 (Hilty et al, 2006), and microsatellite SSR (Ablordey et al, 2007). To determine the geographic linkage from our M. ulcerans isolate, the MLVA results were interpreted according to previously published data (Reynaud et al, 2015). The pattern obtained was JLAAC (VNTR-18: J, VNTR-19: L, MIRU5: A, MIRU33: A, MST1: C) and 34 repeats for the SSR microsatellite.…”