Scanning electron micrograph of Salmonella spp. The flagellae are clearly visible.
Salmonellaare motile, gram negative, aerobic, rod-shaped bacilli of the bacterial family Enterobacteriaceae. The genus Salmonella is obligately pathogenic and is divided into five subgenera that include approximately 2000 serovars. Salmonella can infect a wide variety of mammals, birds, reptiles, and other animals (Wigley, 2004).
Clinical signs for salmonellosisvary according to the host immune status, the number of infecting Salmonella, and the concomitant diseases (Wigley, 2004). Most cases of salmonellosis in animals are asymptotic, but infected animals may exhibit fever, poor appetite, diarrhea, vomiting, and abdominal pain. Generally, salmonellosis infection syndromes can be divided into persistence of an asymptomatic carrier state, gastroenteritis, bacteremia, endotoxemia, and organ localization of the infection.
The diagnosis of salmonellosis is suspected in animals with acute or chronic gastrointestinal illness. However, this is difficult because the clinical and pathological findings of salmonellosis may be indistinguishable from those of other bacterial and viral diseases. Traditional diagnostic methods for salmonellosis include bacterial isolation, immunologic identification, serologic testing, and cytologic examination.
While Salmonella culture remains the gold standard with some limitations, it may take up to five days to obtain final results (Uyttendaele et al., 2003).
The Molecular Diagnostics Laboratory at