Polymerase chain reaction for the detection of Toxoplasma gondii within aqueous humor of experimentally-inoculated cats.

The purpose of this study was to determine the temporal appearance of T. gondii in aqueous humor of cats orally inoculated with T. gondii using polymerase chain reaction (PCR) for the detection of the B1 gene. Serum and aqueous humor were collected from five SPF cats prior to oral inoculation with T. gondii and days 7, 14, 21, 28, 42, 84, 140, 147, 154, 161, 168, and 182 after inoculation. Cats were inoculated orally with T. gondii tissue cysts on day 0 and day 140. T. gondii-specific IgM and IgG were measured in serum and aqueous humor from the cats at each sample data. T. gondii B1 gene PCR was performed on all the aqueous humor samples and the amplified DNA was detected by Southern blotting. Chorioretinitis developed in three out of the five cats, but anterior uveitis was not detected. All cats developed T. gondii-specific IgG titers in serum, and had T. gondii-specific IgG C-values > 1 in both eyes at varying times during the study. T. gondii was detected by PCR and Southern blotting in aqueous humor in both eyes of all cats at times varying from days 14-84 after primary inoculation and days 14-42 after challenge inoculation.