Presence of Salmonella infections in freshwater turtles

Research on salmonella in different species of turtles, and risks to humans

source: F Pasmans et al
Veterinary Record vo150, no 22, June 1 2002
starts p692, 2 pages long

Turtles appear to carry Salmonella while showing no clinical signs, so they present a risk to humans, who can contract Salmonellosis. Commercial turtle farms seek to combat this risk by decontaminating eggs of turtles, but there are still large numbers of juvenile turtles exported with Salmonella infections. Most studies involve ornate terrapins, notably red-eared terrapins, since they have economic importance. This study seeks to assess the prevalence of these infections in several freshwater turtle species, as well as the risk of a serovar Muenchen turtle isolate being transmitted to homeothermic creatures.

The study used 62 turtles from four private owners and 10 pet shops. Samples were either swabs from the soil of aquaria (34 samples) or cloacal swabs (28). The genera included Apalone, Chelydra, Chinemys, Emys, Emydura, Geomyda and Kinosternon. Seven samples were found to be positive, or 11.3%, with three coming from cloacal samples, and four from soil samples. Six serovars were found from I, II and IIb subspecies. Five mice and five chicks were infected using by oral transmission, using S Muenchen from a red-eared terrapin. One mouse died, and the caeca of the other mice and five chickes tested positive for the serovar, while the spleens of two chicks and one mouse were also infected, as was the liver of one mouse. It appears, then, that serovar Muenchen from reptiles can invade birds' and mammals' intestinal tracts.

Most of the isolates came from ornate terrapins that were farm bred, and it is these species which have been subject to preventive measures, do not appear to be totally effective. The seven isolates were from three subspecies of Salmonella enterica, with six different serovars. Turtles have relatively low infection tates, but they can act as a reservoir of Dalmonella serovars that have potential as pathogens for homeothermic animals.