The detection of galactomannan (GM), an antigen secreted by Aspergillus fumigatus, has been developed to improve the diagnosis of invasive aspergillosis in humans. Despite a high sensitivity, GM detection in serum is hampered by a high rate of false positive results which may be associated with the contamination of food by exogenous GM. In the present study, we focused of the detection of GM in milk which is one of the main elements of the food chain. We therefore set a screening of bovine serum and milk samples in order to assess the frequency of GM contamination of milk and to determine whether digestive absorption of GM occurred in cows. Dairy cows were sampled from two veterinary practices in France (Normandy and Jura). The presence and quantity of GM was determined by using ELISA (Platelia Aspergillus®). A total number of 426 milk samples and 426 serum samples were screened. Positive GM assay results were obtained in 2±2% and 22±6% of milk samples from Normandy and Jura, respectively. Positive GM assay results were obtained in 9±3% and 17±4% of serum samples from Normandy and Jura, respectively. In Jura, 90±6% of bovine herds were shown to contain at least one animal with detectable GM in milk. In Normandy, the proportion of positive herds was lower (45±27%). Several parameters, such as food regimen and housing of the cows, may account for the differences observed between the two regions. This study confirmed that GM contamination of the milk occurs and that great variations may be detected according to the origin of the milk.
Full conference title:
The 15 th Congress of the International Society for Human and Animal Mycology
- ISHAM 15th (2003)