Evaluating changes to Ralstonia pickettii in high-purity water to guide selection of potential calibration materials for online water bioburden analyzers.
Kurt D BenksteinSandra M Da SilvaNancy J LinDean C RipplePublished in: Journal of industrial microbiology & biotechnology (2019)
Online water bioburden analyzers (OWBAs) can provide real-time feedback on viable bacteria in high-purity water (HPW) systems for pharmaceutical manufacturers. To calibrate and validate OWBAs, which detect bacteria using scattered light and bacterial autofluorescence, standards are needed that mimic the characteristics of bacteria in HPW. To guide selection of potential standards, e.g., fluorescent microspheres, a relevant bacterial contaminant, Ralstonia pickettii, was characterized for size, count, viability, and autofluorescence after exposure for 24 h to HPW or a nutrient environment. The cells exposed to HPW showed smaller sizes, with lower counts and autofluorescence intensities, but similar spectral features. The cell characteristics are discussed in comparison with a set of fluorescent microspheres, considering factors relevant to OWBAs. These studies suggest that fluorescent microspheres should be relatively small (< 1 µm diameter) and dim, while covering a broad emission range from ≈ (420 to 600) nm to best mimic the representative R. pickettii.
Keyphrases
- quantum dots
- living cells
- social media
- induced apoptosis
- molecularly imprinted
- single cell
- label free
- health information
- peripheral blood
- risk assessment
- healthcare
- optical coherence tomography
- human health
- cell therapy
- cell cycle arrest
- stem cells
- mass spectrometry
- signaling pathway
- magnetic resonance
- fluorescent probe
- endoplasmic reticulum stress
- optic nerve