Molecular Epidemiology of Nontuberculous Mycobacteria in a German CF Center and Clinical Course of NTM Positive Patients

Carolin Kröner,Sören Schubert,Matthias Kappler,Bernd H Belohradsky,Michael Meissner,Gudrun Laniado,Matthias Griese,Michael Hogardt,Ann-Christin Grimmelt,Barbara Ganster

doi:10.4236/ojmm.2013.31006

Carolin Kröner, Sören Schubert + Show 8 more

Open Access

https://doi.org/10.4236/ojmm.2013.31006

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Abstract

Goal of this study was to analyse the clinical course of cystic fibrosis (CF) patients with nontuberculous mycobacteria (NTM) in their respiratory secretions and to investigate the molecular epidemiology of the most prevalent NTM species by multilocus sequence analysis (MLSA). The respiratory specimen and the clinical parameters forced expiratory volume in one second (FEV1), body-mass-index (BMI), erythrocyte sedimentation rate (ESR) 1 h and immunoglobulin G (IgG) of 357 CF patients, 0 - 52.4 years, mean FEV1 2009 81.5% pred were analysed between 1998 and 2010. In 13 patients NTM were detected. 12 of 13 patients carried M. abscessus, for one patient the NTM species was not characterized. 4 patients carried a second NTM species (M. avium, M. chelonae (2x), M. intracellulare). 6 patients exhibited a significant decline in FEV1, however changes in BMI, IgG and ESR were discordant. Molecular genotyping of M. abscessus isolates revealed a unique MLSA pattern in 6 patients. 2 patients harboured identical strains, and one patient a closely related strain. Whether the presence of identical strains is attributed to the acquisition of NTM clones from common environmental sources or to patient-to-patient transmission cannot be definitely clarified. Although cross-in- fection of the three patients with identical/closely related strains in the present cohort is highly unlikely, we recommend strict hygiene measures for all CF patients harbouring NTM.

Highlights

Nontuberculous mycobacteria (NTM) are acid-fast bacilli (AFB) which are ubiquitous in environment, found in soils, water, animals, milk, and food products
The clinical course of NTM positive patients was analysed retrospectively based on the parameters forced expiratory volume in one second (FEV1, % pred), body mass index (BMI, kg/m2) and the inflammatory markers immunoglobulin G (IgG, g/l) and erythrocyte sedimentation rate (ESR 1h, mm)
Reported prevalence rates for cystic fibrosis (CF) patients range between 2% and 28% [9,10,28,29]

Summary

Introduction

Nontuberculous mycobacteria (NTM) are acid-fast bacilli (AFB) which are ubiquitous in environment, found in soils, water, animals, milk, and food products. In contrast to Mycobacterium (M.) tuberculosis human-tohuman transmission appears unlikely for NTM, this view was challenged recently [6]. Several studies have reported prevalence rates of NTM in CF patients between 2% and 28% [1,7,8,9,10]. The results regarding the effect of the NTM infection on the clinical course are controversial [11,12]. The detection rate of NTM was determined in a cohort of CF patients for which strict preventive anti-cross infection policies were in place [13] and the individual clinical course of NTM positive patients. Multi-locus sequence analysis (MLSA) was applied to investigate the molecular epidemiology of the NTM clones in the cohort

Materials and Methods

Specimen Preparation

Clinical Assessment of NTM Positive

Discussion