Detection of Toxoplasma gondii DNA in sera samples of mice experimentally infected

Detection of Toxoplasma gondii (T. gondii) DNA in blood can help to diagnose the disease in its acute phase; however, it must be considered that hemoglobin, present in blood, can inhibit polymerase activity, making impracticable the detection of DNA in samples. Mice were experimentally infected via oral route with ME49 and BTU2 strains cysts and RH strain tachyzoites; polymerase chain reaction was used to detect T. gondii DNA in mice sera 18, 24, 48, 96, and 192 hours post infection (PI). Toxoplama gondii DNA was detected in only one animal infected with BTU2 strain, genotype III (isolated from a dog with neurological signs) 18 hours PI. The agent’s DNA was not detected in any sample of the other experimental groups. New studies must be carried out to verify the technique sensitivity in researches on this agent’s genetic material using sera samples of acute-phase toxoplasmosis patients, especially in cases of immunosuppression

Serological profile of anti-Toxoplasma gondii antibodies in apparently healthy dogs of the city of Botucatu, São Paulo State, Brazil

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii, a coccidian protozoan of worldwide distribution. The seroprevalence in canine population can be an alternative for measuring T. gondii urban spreading. A total of 780 blood samples from dogs were collected, during the yearly anti-rabies campaign, carried out by the Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Husbandry (FMVZ), São Paulo State University, UNESP, together with the county health authorities, in August 1999. Using Indirect Fluorescent Antibody Test (IFAT) for detecting antibodies anti-T. gondii in the sera samples, we observed that 258 dogs (33.1 percent) were positive. The associations between the serological results and the epidemiological variables were studied. Statistically significant differences were not found regarding sex (32.2 percent male and 34.3 percent female reactors). Dogs without a defined breed showed seropositivity statistically higher than the pedigreed group. The occurrence of infection was considered higher with age.

Anti-leptospirose agglutinins in equine sera, from São Paulo, Goias, and Mato Grosso do Sul, Brazil, 1996-2001

Equine leptospirosis can present a non-symptomatic form, an acute clinical form, or even develop chronically, causing reproductive alterations, such as abortion and recurrent uveitis. Since the prevalence of leptospirosis in several countries and regions is widely reported, the objective of this study was to verify the prevailing equine leptospirosis in different regions of Brazil. Sera from 1402 blood samples from horses of different age, sex, breed, and purpose were examined. These samples came from southeastern and central west states of Brazil. The method utilized was the Microscopic Agglutination Test (MAT), with 12 different Leptospira serovars. From the sera tested, 754 (54 percent) were positive for one (385) or more (372) serovars. These results were higher when compared to national and international levels. The most commonly found serovars were icterohaemorrhagiae (37.01 percent), suggesting exposure to rodents, castellonis (16.97 percent), and djasiman (15.19 percent). There were significant differences of reagents between sexes, and a tendency toward higher positivity with age. Distribution of sera-reagents related to aptitude showed a markedly higher value for work animals than for sporting ones. Higher rates were found for animals with undefined breed. There were no significant differences related to regional origin. As an indication of multiple exposure, significant associations were observed between the following serovars: castellonis and djasiman; castellonis and grippotyphosa; castellonis and copenhageni; castellonis and icterohaemorrhagiae; castellonis and pomona; canicola and pomona; canicola and djasiman; djasiman and copenhageni; icterohaemorrhagiae and djasiman; icterohaemorrhagiae and pyrogenes; copenhageni and pomona. These results showed the necessity of further studies on the epidemiology of this disease in equines and its relationship to human illness.