Molecular Analysis of Mycobacteria in Cutting Fluids

Details

• Personal Author:
  Yadav JS
• Description:
  Microbial contaminants particularly nontuberculous mycobacteria (NTM) in metalworking fluids (MWFs) have been implicated in occupational respiratory illnesses such as hypersensitivity pneumonitis (HP) and asthma in exposed machine workers. Conventional approaches for exposure assessment of mycobacteria in metalworking fluid environments often lead to ambiguous (false-negative and false-positive) results, and fail to identify the prevalent mycobacteria to species- and strain-level. Hence there is a need for development of more efficient exposure assessment methods for mycobacteria in these fluids. This project involved development and application of modern DNA-based approaches for efficient monitoring of mycobacteria (both culturable and non-culturable) in MWF. The efforts involved (i) development of PCR-based protocols for real-time detection and quantitation of mycobacteria in water-based MWF; (ii). PCR screening of field samples of different commercial formulations of water-based MWFs for presence of mycobacteria followed by speciation and strain identification of the cultured isolates using optimized molecular typing methods; (iii) investigation to understand the loss of viability of mycobacteria in MWF versus saline and dose-response relationships for different commercially used biocides. The DNA-based methods developed in this study included the following: (1). Genus-specific PCR assays for culture-independent detection of mycobacteria or pseudomonads; (2). mycobacteria-specific real-time PCR assay for culture-independent quantitation of total mycobacteria (both viable and non-viable); (3). PCR-RFLP assays for speciation of MWF mycobacteria that differentiated M. immunogenum from M. chelonae; (4). DNA-fingerprinting methods for strain typing of MWF mycobacterial species. Other related methods developed for exposure assessment and characterization of MWF mycobacteria included the following: (1). Protocol for enhanced selective recovery of mycobacteria from field MWF-in-use; (2). Differential fluorescence-based microscopic assay for viable and non-viable mycobacteria in MWF; (3). Rapid screening method for estimating relative biocidal potential of field MWF samples. Besides method development efforts, the study led to the screening of 101 metalworking fluid samples from geographically diverse regions of North America and led to the isolation of a total of 18 isolates of MWF mycobacteria. These isolates represented two species of Mycobacterium, M. immunogenum and M. chelonae and differed from the one isolated from MWF diluent water (M. diernhoferi); 14 of the isolates could be grouped into 5 distinct novel genotypes, 3 of M. immunogenum and 2 of M. chelonae. These findings changed the existing assumption that MWF-associated mycobacteria lack genetic diversity. Another part of the study led to an understanding of the biocide-induced loss of viability of the isolated mycobacteria in the fluid matrix versus the saline. Survivability of mycobacteria to commercial biocides depended on the MWF matrix and presence of co-contaminants in in-use fluids, and was strain-dependent. The developed state-of-the-art DNA-based methods are adaptable for an effective and early monitoring of the metalworking fluids for presence of mycobacteria and thus could be used to assess and minimize worker exposure to mycobacteria via MWF in the workplace. [Description provided by NIOSH]
• Subjects:
  Lung Diseases Manufacturing And Industrial Facilities Occupational Exposure Occupational Health Respiratory Tract Diseases Safety
• Keywords:
  Deoxyribonucleic Acids DNA Lung Disease Machine Operators Metalworking Fluids MWFs Mycobacterium Occupational Exposure
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-32
• NIOSHTIC Number:
  nn:20056267
• NTIS Accession Number:
  PB2019-101124
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R01-OH-007364, 2012 Sep; :1-32
• Contact Point Address:
  Jagjit S. Yadav, Ph.D., Associate Professor, Department of Environmental Health, University of Cincinnati College of medicine, Cincinnati, OH 45267-0056
• Email:
  Jagjit.Yadav@uc.edu
• Federal Fiscal Year:
  2012
• NORA Priority Area:
  Manufacturing ; Research Tools and Approaches: Risk Assessment Methods
• Performing Organization:
  University of Cincinnati
• Peer Reviewed:
  False
• Start Date:
  20010930
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20170731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:680370f21621c70a1d83c9c696f234e3c49c9a30d489f02c827074e157917484e1ef7f466c8cf5eaf0e26ef8338dec26174a8af48cbf8bb16a61ef46de4055c5
• Download URL:
  https://stacks.cdc.gov/view/cdc/218886/cdc_218886_DS1.pdf
• File Type:
  [PDF - 821.29 KB ]