The effect of a commercial UV disinfection system on the bacterial load of shell eggs

Abstract

Aims: To study the effect of UV irradiation on the bacterial load of shell eggs and of a roller conveyor belt. Methods and Results: The natural bacterial load on the eggshell of clean eggs was significantly reduced by a standard UV treatment of 4·7 s; from 4·47 to 3·57 log CFU per eggshell. For very dirty eggs no significant reduction was observed. Eggs inoculated with Escherichia coli and Staphylococcus aureus (4·74 and 4·64 log CFU per eggshell respectively) passed the conveyor belt and were exposed to UV for 4·7 and 18·8 s. The reduction of both inoculated bacteria on the eggshell was comparable and significant for both exposure times (3 and 4 log CFU per eggshell). Escherichia coli was reduced but still detectable on the conveyor rollers. The internal bacterial contamination of eggs filled up with diluent containing E. coli or S. aureus was not influenced by UV irradiation. Conclusions: There is a significant lethal effect of UV irradiation on the bacterial contamination of clean eggshells and recent shell contamination, contamination of rollers can be controlled and the internal contamination of eggs is not reduced. Significance and Impact of the Study: The penetration of UV into organic material appears to be poor and UV disinfection can be used as an alternative for egg washing.

Bacterial contamination of table eggs and the influence of housing systems

“…De Reu et al (2006a;2006g;2007a) found that natural eggshell contamination of table eggs was dominated by Gram-positive Staphylococcus spp.. Staphylococcus also seems to be the most dominating species in the air of the poultry houses (De Reu et al, 2007a). As major contaminants of egg content; Gram-negative bacteria as Escherichia coli, Salmonella and Alcaligenes sp.…”

The Effects of Using Garlic Extract for Quail Hatching Egg Disinfection on Hatching Results and Performance

“…The use of pre-hatching fumigation in breeding facilities and hatcheries aims at preventing the growth and reducing the numbers of microorganisms such as Salmonella, Escherichia coli, enterobacteria, molds, and yeasts on the eggshell surface (De Reu et al, 2006). Formaldehyde is typically used as a disinfectant of hatching eggs, but other chemicals, as hydrogen peroxide (Cox et al, 2000), Virkon S (Gholami- Ahangaran et al, 2016), propionic acid (Ibrahim et al, 2014), and quaternary ammonium (Arhienowa et al, 1980;Sacco et al,1989) have been tested.…”

Killing bacteria present on surfaces in films or in droplets using microwave UV lamps

“…The E. coli cells were freshly added to the eggshells as in our study and allowed to dry on the surface without complete dehydration. In the present study the bacterial loading within the film was much greater than on the eggs used by De Reu et al (2006) that could not kill the bacteria effectively. Our data has implications for the treatment of heavily fouled surfaces and that almost complete eradication may be possible.…”

“…Recently De Reu et al (2006) showed that UV irradiation can reduce the bacterial content of egg shell surfaces thus preventing internal egg infection and spoilage. They contaminated the surfaces of eggs with E. coli at populations of 10 5 CFU per eggshell and irradiated with UV (intensity at 254 nm = 10 mW cm -2 ) for a period of 4.7 s. A log reduction of 4.47-3.57 per eggshell was observed for the bacterium.…”