Study type: Medical/biological study (experimental study)

Inactivation of Mycobacterium paratuberculosis by pulsed electric fields. med./bio.

Published in: Appl Environ Microbiol 2001; 67 (6): 2833-2836

Aim of study (acc. to author)

To investigate the effects of pulsed electric fields and/or temperature on the viability of the bacterium Mycobacterium paratuberculosis. Furthermore Listeria monocytogenes cells and Bacillus cereus endospores were investigated.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 5 Hz
Exposure duration: 25 min

Exposure 1

Main characteristics
Frequency 5 Hz
Type
Waveform
Exposure duration 25 min
Modulation
Modulation type cf. additional info
Additional info

cells were treated with 2500 pulses at 5, 20 and 50°C

Exposure setup
Exposure source
Chamber uniform field static chamber
Additional info The test chamber consisted of a disk of 10 mm perspex, with a central hole cut through it to hold a 1.9 ml of sample volume. The brass plates were fitted on both sides of the central hole. The test chamber was immersed in a circulating constant temperature water bath.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 30 kV/cm unspecified unspecified - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The viability of Mycobacterium paratuberculosis, suspended either in peptone water or sterilized cow's milk, was effectively reduced by pulsed electric fields at 50°C. Whereas a treatment with pulsed electric fields at lower temperatures or heating alone at 50°C and 70°C, respectively, resulted in less lethality. Electon microscopy studies revealed substantial damages at cellular level to M. paratuberculosis caused by pulsed electric fields. Listeria monocytogenes cells and Bacillus cereus endospores were used to validate the test method.

Study character:

Study funded by