M.V. Collins
S.M. Mitchell
Rebecca A. Cole
G.J. Flick
C.N. Wetch
A. Lindquist
J. P. Dubey
D. S. Lindsay
2003
<p><span>We have been collaborating since 1992 in studies on southern sea otters (</span><i>Enhdyra lutris nereis</i><span>) as part of a program to define factors, which may be responsible for limiting the growth of the southern sea otter population. We previously demonstrated<span> </span></span><i>Toxoplasma gondii</i><span><span> </span>in sea otiers. We postulated that cat feces containing oocysts could be entering the marine environment through storm run-off or through municipal sewage since cat feces are often disposed down toilets by cat owners. The present study examined the sporulation of<span> </span></span><i>T. gondii</i><span>oocysts in seawater and the survival of sporulated oocysts in seawater. Unsporulated oocysts were placed in 1.5 ppt artificial seawater, 32 ppt artificial seawater or 2% sulfuric acid (positive control) at 24 C in an incubator. Samples were examined daily for 3 days and development monitored by counting 100 oocysts from each sample. From 75 to 80% of the oocysts were sporulated by 3 days post-inoculation under all treatment conditions. Groups of 2 mice were fed 10,000 oocysts each from each of the 3 treatment groups. All inoculated mice developed toxoplasmosis indicating that oocysts were capable of sporulating in seawater. Survival of sporulated oocysts was examined by placing sporulated<span> </span></span><i>T. gondii</i><span><span> </span>oocysts in 15 ppt seawater at room temperature 22–24 C (RT) or in a refrigerator kept at 4 C. Mice fed oocysts that had been stored at 4C or RT for 6 months became infected. These results indicate that<span> </span></span><i>T. gondii</i><span><span> </span>oocysts can sporulate and remain viable in seawater for several months.</span></p>
application/pdf
10.1111/j.1550-7408.2003.tb00688.x
en
International Society of Protistologists
Sporulation and survival of Toxoplasma gondii oocysts in seawater
article