Epidemiology and clinical significance of non-tuberculous mycobacteria isolated from pulmonary specimens

Abstract

Setting: A tertiary university medical centre in northern Israel.

Objective: To evaluate the clinical significance of non-tuberculous mycobacteria (NTM) isolated from pulmonary specimens.

Design: Clinical and microbiological data were collected from patient files. Cases were classified as definite, probable and possible NTM.

Results: Between 2004 and 2010, 215 cases with respiratory isolates of NTM were identified. Mycobacterium xenopi was the most common species (n = 84, 39.1%), followed by M. simiae (n = 52, 24.2%). A total of 170 (79.1%) cases were classified as possible and 24 (11.2%) as probable NTM. Only 21 (9.8%) cases were considered definite NTM, the majority of which were M. kansasii and M. avium complex.

Conclusions: M. xenopi and M. simiae are the most prevalent species of NTM isolated from respiratory samples in northern Israel. However, most of these isolates represent colonisation. Of the relatively small number of clinically significant isolates, M. kansasii and M. avium complex were the most common.