Inactivation of Campylobacter jejuni by exposure to high-intensity 405-nm visible light.
Although considerable research has been carried out on a range of environmental factors that impact on the survival of Campylobacter jejuni, there is limited information on the effects of violet/blue light on this pathogen. This investigation was carried out to determine the effects of high-intensity 405-nm light on C. jejuni and to compare this with the effects on two other important Gram-negative enteric pathogens, Salmonella enteritidis and Escherichia coli O157:H7. High-intensity 405-nm light generated from an array of 405-nm light-emitting diodes was used to inactivate the test bacteria. The results demonstrated that while all three tested species were susceptible to 405-nm light inactivation, C. jejuni was by far the most sensitive organism, requiring a total dose of 18 J cm⁻² of 405-nm light to achieve a 5-log₁₀ reduction. This study has established that C. jejuni is particularly susceptible to violet/blue light at a wavelength of 405 nm. This finding, coupled with the safety-in-use advantages of this visible (non-ultraviolet wavelength) light, suggests that high-intensity 405-nm light may have applications for control of C. jejuni contamination levels in situations where this type of illumination can be effectively applied.
Murdoch
Lynne Elizabeth
LE
The Robertson Trust Laboratory for Electronic Sterilisation Technologies, Department of Electronic and Electrical Engineering, University of Strathclyde, 204 George Street, Glasgow, Scotland. lynne.murdoch@strath.ac.uk
Maclean
Michelle
M
MacGregor
Scott J
SJ
Anderson
John G
JG
D002169:Campylobacter Infections / Q000517:prevention & control; D016123:Campylobacter jejuni / Q000528:radiation effects*; D019453:Escherichia coli O157 / Q000528:radiation effects; D005516:Food Microbiology; D008027:Light; D012477:Salmonella enteritidis / Q000528:radiation effects