A Molecular Epidemiological and Genetic Diversity Study of Tuberculosis in Ibadan, Nnewi and Abuja, Nigeria

Lovett Lawson,Olumide M Sogaolu,Stéphanie Le Moullec,Guislaine Refrégier,Luis E Cuevas,Fatima Mohamed,Nnamdi Emenyonu,Saddiq T Abdurrahman,Khye Seng Goh,Michel K Gomgnimbou,Christophe Sola,Gertrude N Uzoewulu,Jian Zhang

doi:10.1371/journal.pone.0038409

Abstract

BackgroundNigeria has the tenth highest burden of tuberculosis (TB) among the 22 TB high-burden countries in the world. This study describes the biodiversity and epidemiology of drug-susceptible and drug-resistant TB in Ibadan, Nnewi and Abuja, using 409 DNAs extracted from culture positive TB isolates.Methodology/Principal FindingsDNAs extracted from clinical isolates of Mycobacterium tuberculosis complex were studied by spoligotyping and 24 VNTR typing. The Cameroon clade (CAM) was predominant followed by the M. africanum (West African 1) and T (mainly T2) clades. By using a smooth definition of clusters, 32 likely epi-linked clusters related to the Cameroon genotype family and 15 likely epi-linked clusters related to other “modern” genotypes were detected. Eight clusters concerned M. africanum West African 1. The recent transmission rate of TB was 38%. This large study shows that the recent transmission of TB in Nigeria is high, without major regional differences, with MDR-TB clusters. Improvement in the TB control programme is imperative to address the TB control problem in Nigeria.

Highlights

Multi-drug-resistant Mycobacterium tuberculosis (MDR-TB) has emerged as a major global public health problem [1]
The four spoligotype profiles characteristic of M. bovis showed the absence of spacer 30 which is a specific characteristic of the ‘‘African 1’’ M. bovis genotype family previously described as predominant in Western Central Africa (Nigeria, Cameroun, Mali, Chad) [20]
No significant statistical differences were detected regarding transmission in the different centers a tendency for higher transmission in Abuja and Nnewi was detected (Table 3). This is the largest and most detailed genetic characterisation on Mycobacterium Tuberculosis Complex (MTBC) clinical isolates of patients suffering from TB in Nigeria relying on the analysis of isolates from three main cities [2]

Summary

Introduction

Multi-drug-resistant Mycobacterium tuberculosis (MDR-TB) has emerged as a major global public health problem [1]. Despite the ever growing importance of TB in Nigeria, available molecular epidemiological studies do not represent an extensive picture of TB epi-links in this country due to non-standard genotyping protocols and restricted sampling areas [3,4,5,6]. This is due to molecular diagnostic methods being until now poorly adapted to high TB prevalence due to high costs or suboptimal protocols to ensure epi-links detection. This study describes the biodiversity and epidemiology of drug-susceptible and drug-resistant TB in Ibadan, Nnewi and Abuja, using 409 DNAs extracted from culture positive TB isolates

Methods

Results

Conclusion