![]() mallei, purified from soluble components. Here we describe a new Western blot assay based on an easy to prepare LPS preparation containing antigen from B. mallei are time consuming, sophisticated and hazardous for the operator. But current protocols for the extraction and purification of LPS from B. Lipopolysaccharide (LPS) preparations have already been applied in Western blot analysis or competition ELISA to detect anti- B. However, in glanders free areas or in areas with very low prevalence of glanders highly specific tests are needed to minimize the number of false positive results. ![]() These techniques are useful in eradication programs with regard to specificity and sensitivity. Glanders was eradicated from Western Europe, Australia and North America in the last century applying a rigorous culling of horses found positive in complement fixation and mallein test. In general, serological tests may be negative in emaciated and chronically debilitated animals suffering from glanders. The test can also not be applied on sera having so called "anticomplementary activity". False positive results due to cross-reactions may be seen in horses suffering from strangles, equine influenza or petechial fever. The CFT has a sensitivity of at least 97% but a notable number of unspecific, false positive results occur. The CFT for glanders is so far the only officially recognized serological test in international trade of equidae. mallei infection still relies on serological proof by agglutination test and complement fixation test (CFT), or proof of the presence of a specific delayed hypersensitivity reaction after intracutaneous application of mallein. The distribution of glanders in Africa is unknown. Recent outbreaks have been reported from Turkey, the United Arabic Emirates, Iraq, Iran, India, Pakistan, Mongolia, China, Brazil and most recently from Bahrain. The disease is still endemic in the Middle East, Asia and South America. Glanders, caused by Burkholderia (B.) mallei, is a highly contagious disease in equines which is notifiable to the World Organisation of Animal Health (OIE, Office International des Epizooties). Its use for international trade of horses and mules should be implemented by the OIE. The CFT should be amended by the newly validated Western blot to increase the positive likelihood ratio of glanders serodiagnosis in non endemic areas or areas with low glanders prevalence. However, the CFT remains the test of choice for routine testing of glanders due to its high sensitivity, its feasibility using standard laboratory equipment and its worldwide distribution in diagnostic laboratories. The developed Western blot assay showed a markedly higher diagnostic specificity when compared to the prescribed CFT and therefore can be used as a confirmatory test. The test was validated investigating a comprehensive set of positive and negative sera obtained from horses and mules from endemic and non endemic areas. Hence, a Western blot assay making use of a partly purified lipopolysaccaride (LPS) containing antigen of three Burkholderia mallei strains was developed. Consequently, there is an urgent need to develop a test with high specificity. Frequently observed false positive results are troublesome for veterinary authorities and cause financial losses to animal owners. The in vivo diagnosis of glanders relies on the highly sensitive complement fixation test (CFT).
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