Non-tuberculous mycobacteria (NTM) frequently colonize the modem metalworking fluids (MWFs) and are increasingly being implicated in occupational respiratory illnesses such as hypersensitivity pneumonitis (HP) in machine workers. Their early detection/recovery and characterization will help take pre-emptive measures and develop intervention strategies. Our first funding has led to the development of PCR based protocols for culture-independent detection and quantification of NTM in water-based MWF, coupled with isolation and genotypic identification of several NTM strains from MWF, which belonged to two species M. immunogenum and M. chelonae. Our proposed future goals are to develop next generation of simplified DNA-based approaches that can be adapted in in-house laboratories and to investigate the relative biocide susceptibility and antigenic potential of these MWF isolated NTM strains (genotypes).
The specific aims are (1). to develop protocols for efficient NTM recovery and simple DNA-based detection and quantification of NTM from different MWF types; (2). to determine the relative biocide susceptibility of the available and new NTM strains from MWF by optimization and use of a high throughput protocol; (3). to investigate antigenic characteristics of the available and HP-linked NTM strains. Immunomagnetic separation using Mycobacterium-specific polyclonal antibodies will be developed for selective cell recovery for improved NTM detection and cultural isolation. Our current PCR protocol will be adapted for colorimetric detection of NTM. A new protocol based on Fluorescence in-situ hybridization (FISH) will be developed for microscope- assisted culture-independent detection and quantification of the MWF-specific mycobacterial species. A high throughput protocol based on intracellular ATP will be optimized and used for measurement ofbiocide susceptibility. Relative antigenic potential of the MWF-prevalent strains/genotypes will be determined based on cellular immune response in the sensitized blood cells from HP patients or MWF exposed workers. M. immunogenum polyclonal antibodies or HP patient sera will be applied as probes to identify the putative protein antigens in the cell protein lysates and culture filtrates of the identified antigenic strain. The resulting information will help NORA's objectives by providing a set of practical methods for mycobacterial contamination- and exposure- assessment and a strain characteristics database, for facilitating development of intervention strategies related to MWF exposures.
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