The contribution of red poultry mites (Dermanyssus gallinae (Degeer 1778) (Acari: Dermanyssidae)) to the cross contamination of poultry with Campylobacter spp. and Salmonella spp. and the acaricidal effect of carvacrol, thymol, bay oil and neem oil on Dermanyssus gallinae

Abstract

Food borne infections are the cause of many illnesses and cost the Netherlands tens of millions of euro’s every year. The most important food borne pathogens are Campylobacter spp. and Salmonella spp. Poultry products are important carriers of these pathogens. This is why it is important to eradicate these pathogens from the poultry system. Poultry mites have infested more than 80 % of the Dutch poultry and cost the poultry industry millions every year according to the Animal Sciences Group. In this study poultry mites were tested if they carried Campylobacter spp. and Salmonella spp. and in this way contributed to the cross infection of poultry flocks. It was concluded that the red poultry mite, Dermanyssus gallinae De Geer, does not carry Campylobacter spp. and thus the infection of the mites can not be correlated with the Campylobacter status of the farm. Correlation between the Salmonella status of the flock and infection of the mites could not be tested in this study for there were no flocks found positive for Salmonella. The second aim of this study was to test the acaricidal effect of carvacrol, thymol, bay oil and neem oil on Dermanyssus gallinae using direct contact and vapour. For the contact test carvacrol and thymol had the highest mean mortality percentage of a 100 % at 0.5 % suspension, followed by bay oil and neem oil. Significant difference between acaricidal activity at different temperatures (20°C and 30°C) were only found for bay oil at 0.5 % and neem oil at 2 %. Carvacrol and thymol also had high mean mortality percentages (approximately 85 %) in the vapour tests, but never 100 %; indicating that contact with these substances is more effective than vapour. Looking at the acaricidal effectiveness of carvacrol and thymol, they can be considered for practical use in the future.