Isolation of nitrate-reductase positive Corynebacterium pseudotuberculosis from dromedary camels

Abstract

Corynebacterium pseudotuberculosis is the causative organisms of caseous lymphadenitis (pseudotuberculosis) in sheep and goats (Lloyd et al. 1990; Lindsay and Lloyd 1991). This condition is characterized by abscessation of one or more lymph nodes, but sometimes presents as pneumonia, hepatitis, mastitis, arthritis, orchitis and subcutaneous abscesses. Corynebacterium pseudotuberculosis is associated with lymphadenitis in horses and ulcerative lymphangitis in cattle (Sutherland et al. 1993; Aleman et al. 1996; Miers and Ley 1980) and affects rarely in human beings (Peel et al. 1997). Pseudotuberculosis occurs worldwide and it has also been described in camels in several countries (Wernery and Kaaden 2002). Two biotypes of C. pseudotuberculosis, based on nitrate-reducing ability, have been reported and these biotypes can be correlated with different genotype patterns (Songer et al. 1988; Sutherland et al. 1996). Isolates from sheep and goats were nitrate negative whereas those from horses were nitrate positive. Reactions from cattle isolates were variable. Strains that reduce nitrate are referred as biotype equi and strains that fail to do so are referred as biotype ovis. Barakat et al. (1984) found two serotypes referred as type I and type II which corresponded with nitrate reductase negative and positive strains, respectively. In camels, only the serotype I (biotype ovis) has been described in the available literature (Wernery and Kaaden 2002). A study on pseudotuberculosis in camels was carried out in the Canary Islands, using 13 affected dromedaries, and isolating C. pseudotuberculosis biotype ovis in all cases (Tejedor et al. 2004). This communication presents the isolation of Corynebacterium pseudotuberculosis nitrate reductase positive from two camels belonging to the same herd and located in Canaries.