Development and validation of a method for purification of mallein for the diagnosis of glanders in equines

The TFF methodology efficiently separated the high and low molecular weight protein groups of mallein. The five TFF-purified malleins, produced from Burkholderia mallei strains isolated from clinical cases of glanders in Brazil, proved to be more potent than standard mallein in the induction of an allergic reaction in sensitized animals. Regarding specificity, two of the purified malleins were equivalent to the standard and three were less specific.Some of the TFF-purified malleins showed considerable potential to be used as an auxiliary test in the diagnosis of glanders.Glanders occurs primarily in equines, but other species, including humans, may become incidental hosts [1]. The causal agent of glanders is the bacterium Burkholderia mallei, a small, Gram negative, non-motile, encapsulated, facultative intracellular rod [2,3]. The disease presents in three main forms: pulmonary, nasal and cutaneous [4]. In horses, glanders is usually chronic, and the infected animal may live for years. In donkeys and mules, the acute form is more common, and the infected animals may die in a few days. Transmission of glanders occurs mainly by the ingestion of food and water contaminated by the secretions of animals with the clinical and sub-clinical forms of the disease and is exacerbated by crowded, unhealthy living conditions. Sharing of grooming and riding equipment is also considered an important form of transmission. [5-7].Glanders was eradicated from Western Europe and North America [8] but is still present in Asia, the Middle East and South America [9-14]. In Brazil, glanders was first described in 1811 and was most likely introduced by the importation of infected horses from Europe [15]. From 1960 to 1998, the disease was not reported in the country. In 1999, though, it was diagnosed in the Brazilian northeastern states of Pernambuco and Alagoas [14], and subsequently, some foci were reported in other regions of the country [16]. The regulatory legislation for the control a