High clustering rates of multidrug-resistant Mycobacterium tuberculosisgenotypes in Panama

Samantha Rosas,Amador Goodridge,Jaime Bravo,Joel Sanchez,Nora De Moreno,Ronnie G Gavilan,Franklin Gonzalez

doi:10.1186/1471-2334-13-442

Abstract

BackgroundTuberculosis continues to be one of the leading causes of death worldwide and in the American region. Although multidrug-resistant tuberculosis (MDR-TB) remains a threat to TB control in Panama, few studies have focused in typing MDR-TB strains. The aim of our study was to characterize MDR Mycobacterium tuberculosis clinical isolates using PCR-based genetic markers.MethodsFrom 2002 to 2004, a total of 231 Mycobacterium tuberculosis isolates from TB cases country-wide were screened for antibiotic resistance, and MDR-TB isolates were further genotyped by double repetitive element PCR (DRE-PCR), (GTG)5-PCR and spoligotyping.ResultsA total of 37 isolates (0.85%) were resistant to both isoniazid (INH) and rifampicin (RIF). Among these 37 isolates, only two (5.4%) were resistant to all five drugs tested. Dual genotyping using DRE-PCR and (GTG)5-PCR of MDR Mycobacterium tuberculosis isolates revealed eight clusters comprising 82.9% of the MDR-TB strain collection, and six isolates (17.1%) showed unique fingerprints. The spoligotyping of MDR-TB clinical isolates identified 68% as members of the 42 (LAM9) family genotype.ConclusionOur findings suggest that MDR Mycobacterium tuberculosis is highly clustered in Panama’s metropolitan area corresponding to Panama City and Colon City, and our study reveals the genotype distribution across the country.

Highlights

Tuberculosis continues to be one of the leading causes of death worldwide and in the American region
From 2002 to 2004, the Panamanian National TB Program (NTBP) reported a total of 4507 new pulmonary TB cases country-wide
Thirty-seven isolates collected between 2002 and 2004 demonstrated resistance to at least INH and RFP, and these isolates were defined as MDR Mycobacterium tuberculosis

Summary

Introduction

Tuberculosis continues to be one of the leading causes of death worldwide and in the American region. Multidrug-resistant tuberculosis (MDR-TB) remains a threat to TB control in Panama, few studies have focused in typing MDR-TB strains. The aim of our study was to characterize MDR Mycobacterium tuberculosis clinical isolates using PCR-based genetic markers. Mycobacterium tuberculosis (M. tuberculosis) is the bacterium that causes tuberculosis (TB), which is the world’s leading infectious killer after human immunodeficiency virus (HIV). TB control has been impaired by the persistence of multidrug-resistant M. tuberculosis (MDR-TB). In 2011, Panama reported 1301 new pulmonary TB cases, including an estimated seven MDR-TB cases [2]. The estimated average prevalence of MDR-TB in Panama for 2011 was approximately 0.5%; a more detailed country-wide surveillance project is underway [2]. Novel diagnosis and biomarker tests for monitoring the treatment response in MDR-TB cases are currently under evaluation

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Results