Cross-sectional survey of Toxoplasma gondii infection in colony cats from urban Florence (Italy).

Cats are the key species in the epidemiology of Toxoplasma gondii infection, even if the proportion of subjects excreting oocysts is low. The aim of the present paper was to obtain information about seroprevalence, oocyst shedding rate and presence of T gondii DNA in faeces collected from an urban population of colony cats in Florence (Tuscany). Fifty European shorthair feral cats were examined for anti-T gondii specific antibodies by a modified agglutination test (MAT), and for oocysts by microscopic examination and for faecal protozoal DNA, by means of a nested polymerase chain reaction (n-PCR) protocol. Twenty-two out of 50 serum samples (44%) were MAT positive. T gondii oocysts were not detected in any of the examined faecal samples. Eight out of 50 faecal specimens (16%) were n-PCR positive and sequencing of the bands was specific for T gondii. Detection by combination of the two methods was higher than single techniques and enhanced the detection of T gondii up to 48%. Our results suggest that the use of MAT plus PCR in faeces may be the best choice for diagnosis of feline toxoplasmosis. Further studies to ascertain the real infectivity of the copro-PCR positive subjects are required.