title: Increased isolation of nontuberculous mycobacteria among TB suspects in Northeastern, Tanzania: public health and diagnostic implications for control programmes.
abstract: BACKGROUND
  Non-tuberculous mycobacteria (NTM) are increasingly reported worldwide associated with human disease. Defining the significance of NTM in settings with endemic tuberculosis (TB) requires the discrimination of NTM from TB in suspect patients. Correct and timely identification of NTM will impact both therapy and epidemiology of TB and TB-like diseases. The present study aimed at determining the frequency and diversity of NTM among TB suspects in northeastern Tanzania.
  
  
  METHODS
  A cross-sectional study was conducted between November 2012 through January 2013. Seven hundred and forty-four sputum samples were collected from 372 TB suspects. Detection was done by using phenotypic, GenoType(®) Mycobacterium CM/AS kits, 16S rRNA and hsp65 gene sequencing for identification of isolates not identified by Hain kits. Binary regression model was used to analyse the predictors of NTM detection.
  
  
  RESULTS
  The prevalence of NTM was 9.7% of the mycobacterial isolates. Out of 36 patients with confirmed NTM infection, 12 were HIV infected with HIV being a significant predictor of NTM detection (P < 0.001). Co-infection with Mycobacterium tuberculosis (M. tb) was found in five patients. Twenty-eight NTM isolates were identified using GenoType(®) Mycobacterium CM/AS and eight isolates could not be identified. Identified species included M. gordonae and M. interjectum 6 (16.7%), M. intracelullare 4 (11.1%), M. avium spp. and M. fortuitum 2 (5.5%), M. kansasii, M. lentiflavum, M. simiae, M. celatum, M. marinum 1 (2.8%) each. Of isolates not identified to subspecies level, we identified M. kumamotonense (2), M. intracellulare/kansasii, M. intermedium/triplex, M. acapulcensis/flavescens, M. stomatepiae, M. colombiense and M. terrae complex (1) each using 16S rRNA sequencing. Additionally, hsp65 gene sequencing identified M. kumamotonense, M. scrofulaceum/M. avium, M. avium, M. flavescens/novocastrense, M. kumamotonense/hiberniae, M. lentiflavum, M. colombiense/M. avium and M. kumamotonense/terrae/hiberniae (1) each. Results of the 16S rRNA and hsp65 gene sequencing were concordant in three and discordant in five isolates not identified by GenoType(®) Mycobacterium CM/AS.
  
  
  CONCLUSIONS
  NTM infections may play a vital role in causing lung disease and impact management of TB in endemic settings. GenoType(®) Mycobacterium CM/AS represents a useful tool to identify clinical NTM infections. However, 16S rRNA gene sequencing should be thought for confirmatory diagnosis of the clinical isolates. Due to the complexity and inconsistence of NTM identification, we recommend diagnosis of NTM infections be centralized by strengthening and setting up quality national and regional infrastructure.
authors.affiliation: Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University of Leipzig, Liebigstrasse 21, 04103, Leipzig, Germany. abshoza@gmail.com.|Sokoine University of Agriculture, Morogoro, Tanzania. abshoza@gmail.com.
authors.forename: Abubakar S
authors.initials: AS
authors.lastname: Hoza
authors.affiliation: Muhimbili Centre, National Institute for Medical Research (NIMR), Dar es Salaam, Tanzania. gsmfinanga@yahoo.com.
authors.forename: Sayoki G M
authors.initials: SG
authors.lastname: Mfinanga
authors.affiliation: Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University of Leipzig, Liebigstrasse 21, 04103, Leipzig, Germany. acr@medizin.uni-leipzig.de.
authors.forename: Arne C
authors.initials: AC
authors.lastname: Rodloff
authors.affiliation: Federal Research for Animal Health, Friedrich Loeffler Institut, Jena, Germany. irmgard.moser@fli.bund.de.
authors.forename: Irmgard
authors.initials: I
authors.lastname: Moser
authors.affiliation: Institute of Medical Microbiology and Epidemiology of Infectious Diseases, University of Leipzig, Liebigstrasse 21, 04103, Leipzig, Germany. brigitte.koenig@medizin.uni-leipzig.de.
authors.forename: Brigitte
authors.initials: B
authors.lastname: König
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001426:Bacterial Proteins; D015373:Bacterial Typing Techniques; D018834:Chaperonin 60; D002648:Child; D060085:Coinfection; D003140:Communicable Disease Control / Q000458:organization & administration; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D006678:HIV / Q000235:genetics; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D009170:Nontuberculous Mycobacteria / Q000235:genetics* / Q000302:isolation & purification; D011634:Public Health; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013636:Tanzania / Q000453:epidemiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D012336:RNA, Ribosomal, 16S; C074119:heat-shock protein 65, Mycobacterium