Effect of sunlight on the survival of Salmonella on surfaces.
OBJECTIVE
To investigate the effect of simulated full-spectrum tropical sunlight on the survival of Salmonella in droplets on surfaces.


RESULTS
The survival on surfaces of three Zambian strains of Salmonella enterica serovars Enteritidis and Heidelberg was compared with that of a strain of S. enterica serovar Enteritidis phage type (PT) 4 with known characteristics which had been isolated from poultry in the UK. Samples were taken from surfaces every hour for 3 h and after 24 h exposure in either dark or 12 h light/12 h dark cycle conditions. Differences were analysed for significance using a one-way analysis of variance (anova). Results show that there were a significantly higher number of cells surviving on surfaces after 24 h in the dark when compared with populations exposed to a 12 h light/12 h dark cycle. Significantly more cells also survived exposure to sunlight under dirty than clean conditions.


CONCLUSIONS
Exposure to sunlight results in a significant decrease in numbers of Salmonella on surfaces.


CONCLUSIONS
Under field conditions exposure of contaminated surfaces to sunlight could be used in place of chemical methods of control as a cheaper way to reduce Salmonella contamination of surfaces.
Ministry of Agriculture and Co-operatives, Central Veterinary Research Institute, Lusaka, Zambia. charles.nyeleti@bristol.ac.uk
C
C
Nyeleti
T A
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Cogan
T J
TJ
Humphrey
D000818:Animals; D015169:Colony Count, Microbial / Q000379:methods; D003624:Darkness; D003666:Decontamination; D004781:Environmental Exposure; D011200:Poultry / Q000382:microbiology; D012475:Salmonella / Q000254:growth & development / Q000528:radiation effects*; D012483:Salmonella Phages / Q000528:radiation effects; D012477:Salmonella enteritidis / Q000254:growth & development / Q000528:radiation effects; D013472:Sunlight; D014329:Tropical Climate