title: Prevalence and species spectrum of both pulmonary and extrapulmonary nontuberculous mycobacteria isolates at a tertiary care center.
abstract: Nontuberculous mycobacteria (NTM) infection associated with pulmonary and extrapulmonary disease has been increasing globally. Despite an increase in incidence rate of NTM infection, its prevalence, species diversity, and circulation pattern in India is largely unknown. This study sought to investigate the overall burden and diversity of NTM among both pulmonary and extrapulmonary clinical isolates from a Northern Indian population.
  
  
  
  The study was conducted in the Department of Microbiology, from January 2013 to December 2015. A total of 4620 clinical samples were collected from patients suspected to have pulmonary and extrapulmonary tuberculosis. Preliminary diagnosis was performed using Ziehl-Neelsen staining followed by liquid culture in BacT/ALERT three-dimensional system. A total of 906 positive cultures obtained were differentiated as either NTM or Mycobacterium tuberculosis complex using a biochemical and MPT64 antigen test. Further identification of NTM species was confirmed with a line probe assay.
  
  
  
  Out of 906 cultures isolates, 263 (29.0%) were confirmed as NTM and 643 (71.0%) were identified as Mycobacterium tuberculosis complex. A total of 79.4% of the NTM were recovered from pulmonary and 18.2% from extrapulmonary specimens. The diversity of NTM species was high (13 species) and predominated by Mycobacterium abscessus (31.3%) followed by Mycobacterium fortuitum (22%), Mycobacterium intracellulare (13.6%), Mycobacterium chelonae (9.1%), however, M. abscessus and M. fortuitum were the predominant species in both types of clinical isolates. Men (60.4%) and older patients aged greater than 55years were the predominated risk group for NTM infection.
  
  
  
  The high prevalence and species diversity of NTM suggests the need for immediate and accurate characterization of NTM for proper treatment and management of patients.
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow, India; Department of Microbiology, Sri Satya Sai University of Technology and Medical Sciences, Bhopal, India.
authors.forename: Jyoti
authors.initials: J
authors.lastname: Umrao
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow, India.
authors.forename: Dharamveer
authors.initials: D
authors.lastname: Singh
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow, India.
authors.forename: Amreen
authors.initials: A
authors.lastname: Zia
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow, India.
authors.forename: Swati
authors.initials: S
authors.lastname: Saxena
authors.affiliation: Department of Microbiology, Sri Satya Sai University of Technology and Medical Sciences, Bhopal, India.
authors.forename: Surendra
authors.initials: S
authors.lastname: Sarsaiya
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow, India.
authors.forename: Shushma
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow, India.
authors.forename: Jahanarah
authors.initials: J
authors.lastname: Khatoon
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareli Road, Lucknow, India. Electronic address: tndhole@gmail.com.
authors.forename: Tapan N
authors.initials: TN
authors.lastname: Dhole
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001431:Bacteriological Techniques; D002648:Child; D002675:Child, Preschool; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D009165:Mycobacterium Infections, Nontuberculous / Q000453:epidemiology* / Q000382:microbiology*; D009170:Nontuberculous Mycobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D015995:Prevalence; D011446:Prospective Studies; D062606:Tertiary Care Centers; D055815:Young Adult
keywords: Liquid culture; Mycobacterium tuberculosis complex; Nontuberculous mycobacteria; Species identification