Citrobacter freudii septicemia in a newborn stranded whale (Ziphius cavirostris)

Abstract

Citrobacter freundii, a gram-negative bacterium of the Enterobacteriaceae family, is considered a ubiquitous and opportunistic pathogen. In humans, Citrobacter spp. have been associated with urinary tract infections, respiratory infections, bacteremia, septicemia and meningitis (Doran, 1999; Drelichman and Band, 1985). From a group of human cases diagnosed of Citrobacter freundii septicemia, 48% died (Drelichman and Band, 1985). In humans, person to person contact appears to be the usual mode of transmission; in young children, maternal transmission is possible (Doran, 1999) and Citrobacter koseri and C. freundii have been reported in vertically acquired infection (Doran, 1999; Malpas et al., 2003). In veterinary sciences, Citrobacter freundii is a potential cause of bacteremia-septicemia in puppies or immunocompromized adult dogs (Galarneau et al., 2003). C. freundii has infrequently been identified in cetaceans (Higgins, 2000), and although not reported as a cause of death, a carrier state and its likely importance in relation to dolphin health have been hypothesized (Buck et al., 2006). Here we report a case of a stranded neonatal beaked whale showing a bacteremia–septicemia caused by a systemic infection of Citrobacter freundii.