Submitted to: International Association for Food Protection Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 3/1/2002
Publication Date: 8/1/2002
Citation: Chantarapanout, W., Berrang, M.E., Frank, J. 2002. Direct microscopic observation and visualization of viability for detectionof campylobacter jejuni on chicken skin. [abstract] International Association for Food Protection Proceedings. Interpretive Summary:
Technical Abstract: The objective of this study was to develop a method to identify specific sites on chicken skin, which allow Campylobacter jejuni survival. This method employs confocal laser scanning laser microscopy (CSLM) visualization of Campylobacer jejuni transformed with Pcgfp plasmid (GFP-Campylobacter) exposed to 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), a redox dye which is taken up, reduced to CTC-formazan, and accumulated intracellularly in respiratory active cells. An Ar/Kr laser (excitation wavelength [l] = 488 nm) was used to excite both GFP- Campylobacter and CTC. The emission wavelength of 500-563 nm was assigned as green color for GFP-Campylobatcer image, 600-680 nm as red color for CTC image, and 483-499 as grey color for chicken skin- reflected light. After 1 h inoculation with 2 ml of 108-109 cfu/ml GFP- Campylobacter suspension, 105-106 cfu of C. jejuni remained on 1 cm2 of chicken breast skin after rinsing. Green fluorescence of all C. jejuni colonies as well as the CTC-formazan in viable Campylobacter was clearly visible on chicken skin. The data indicated that GFP-Campylobacter remaining on the chicken skin surface after rinsing were mostly located in crevices, entrapped inside feather follicles with water and also entrapped in the surface water layer. Most of viable cells were entrapped with water in the skin crevices and feather follicles. These sites provide suitable microenvironment for GFP-Campylobacter to survive.