Significance and Use
5.1 This practice allows for the recovery and enumeration of viable and culturable, non-tuberculosis, rapidly growing Mycobacteria (M.immunogenum, M.chelonae, M. absessus, M. fortuitum , and M.smegmatis) in the presence of high gram negative background populations in metalworking fluid field samples. During the past decade it has become increasingly apparent that non-tuberculous Mycobacteria are common members of the indigenous MWF bacterial population. This population is predominantly comprised of gram negative bacteria and fungi. Mycobacterial contamination of metalworking fluids has been putatively associated with hypersensitivity pneumonitis (HP) amongst metal grinding machinists. The detection and enumeration of these organisms will aid in better understanding of occupational health related problems and a better assessment of antimicrobial pesticide efficacy.
5.2 The measurement of viable and culturable mycobacterial densities combined with the total mycobacterial counts (including viable culturable (VC), viable-non culturable (VNC) and non viable (NV) counts) is usually the first step in establishing any possible relationship between Mycobacteria and occupational health concerns (for example, HP).
1.1 This practice covers the detection and enumeration of viable and culturable rapidly growing Mycobacteria (RGM), or non-tuberculosis Mycobacteria (NTM) in aqueous metalworking fluids (MWF) in the presence of high non-mycobacterial background population using standard microbiological culture methods.
1.3 This practice involves culture of organisms classified as Level 2 pathogens, and should be undertaken by a trained microbiologist in an appropriately equipped facility. The microbiologist should also be capable of distinguishing the diverse colonies of Mycobacteria from other microorganism colonies on a Petri dish and capable of confirming Mycobacteria by acid fast staining method