Toxoplasma gondii is a zoonotic parasite with global distribution capable of infecting homeothermic animals. Transmission of protozoan to humans includes ingestion of water and raw food contaminated ...with sporulated oocysts, ingestion of raw or undercooked meat with tissue cysts, and tachyzoites’ transplacental transmission. Fresh goat milk intake has already been linked to human toxoplasmosis outbreaks, but little is known about the infectious potential of this biological sample. Accordingly, the aim of the present study is to assess the survival and infectivity of T. gondii tachyzoites in fresh goat milk samples through an experimental protocol to detect this parasite via bioassay carried out with a murine model, DNA amplification, and serology. Swiss Webster mice were inoculated with fresh goat milk samples contaminated with different T. gondii RH strain tachyzoite concentrations per milliliter and stored for different refrigeration times. Animals showing clinical signs compatible to toxoplasmosis were euthanized. Milk samples contaminated with high parasitic loads and kept for a shorter refrigeration time were the most lethal ones. No significant differences were observed between mean death rates recorded for different goat milk contamination concentrations ( p = 0.1888), and for the refrigeration time, contaminated milk samples were kept under ( p = 0.9440). T. gondii DNA was amplified in all contaminated milk samples, but only one of the surviving mice was serologically positive. Results of the present study have shown T. gondii survival and infectivity in fresh goat milk samples, and it highlights its significant risk for public health. Therefore, molecular methods must be the tests of choice when milk samples are used to assess infection caused by protozoan in goats’ dairy products.
The highly virulent
RH strain is maintained through successive passages in mice, but there is still a lack of studies that refine these procedures from a 3Rs perspective, where humanitarian ideals ...aim to minimize the stress, pain, or suffering of the animals used in the research without the loss of results. The aim of this study was to establish humane endpoints in Swiss Webster mice inoculated with the
RH strain. A total of 52 mice were infected with 5 × 10
tachyzoites/mL and monitored for periods of up to 5 days. The parameters body weight; hair condition; higher than normal body temperature; hypothermia; respiratory function; pain; soft stools or diarrhea; bloody diarrhea; tense, nervous, or in distress during handling; and ascites were recorded daily in score tables. The results showed that prominent piloerection, respiratory function, pain parameters, and ascites are important clinical signs to be used as a cut-off point for implementing euthanasia. The application of this refinement method helped to avoid animal suffering and pain without compromising the number of parasites recovered. We therefore suggest adopting these parameters in research protocols that require the maintenance of the
RH strain in murine models to avoid and reduce animal suffering.
Toxoplasma gondii was isolated in mice from different tissues of a captive black-and-gold howler monkey (Alouatta caraya) kept in a colony at the Primatology Center of Rio de Janeiro State, Brazil, ...and it was genotypically characterized based on using PCR-RFLP and Microsatellite Analysis (MS), later on. T. gondii was successfully isolated from inocula deriving from heart, liver and tissue pool (heart, liver, lungs, axillary lymph nodes and cerebellum) samples. The isolate was named TgBgHmBrRJ1. The high virulence of the aforementioned strain was observed in infected mice. Non-archetypal genotype (ToxoDB PCR-RFLP #206) was obtained through PCR-RFLP. This genotype had been previously described in 12 isolates from different hosts, also in Southeastern Brazil, a fact that indicates likely high circulation of this genotype in this region. The isolate was also classified as non-archetypal, based on MS genotyping, as well as presented genotypic identity close to that of strains isolated from free-range non-symptomatic chickens (TgCkBr244,245,278,279) in Espírito Santo State. It is worth emphasizing that despite the large number of reports about clinical toxoplasmosis in neotropical primates in Brazil, this is just the second isolate of this parasite ever reported in this group of animals.
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•Toxoplasma gondii was isolated in a murine model from Alouatta caraya in captivity.•An intermediate virulence of the isolated in the infected murine model was verified.•A non-archetypal genotype (ToxoDB PCR-RFLP #206) was obtained by PCR-RFLP.•This is the second isolation of T. gondii from a non-human primate in Brazil.•For the first time, this genotype was associated with clinical disease in a host.
Urban canine and feline populations are expanding worldwide, a fact that can boost the transmission of zoonotic parasites. Thus, it is necessary understanding dog and cat owners’ profile, as well as ...their perceptions about zoonoses, to develop preventive strategies based on the One Health approach. The aim of the current study is to compare the profile of dog and cat owners, whose domestic pets were treated at Jorge Vaitsman Veterinary Medicine Center, Rio de Janeiro, Brazil. Dog and cat owners, whose domestic pets were treated in the routine service of the aforementioned medical clinic, from August 2017 to November 2018, filled a structured questionnaire comprising closed questions in order to collect information about their socioeconomic profile, hygiene habits, animal care and knowledge about parasites. Comparative analysis was applied to data collected from dog and cat owners, based on using Fischer's Exact Test or Pearson's Chi-square. In total, 350 individuals - 244 dog owners and 106 cat owners - filled the questionnaire. The comparative analysis of socioeconomic profile, animal care, sanitary practices and knowledge about parasites did not show differences between dog and cat owners (p≥0.05). Animal vaccination and deworming practices were significantly more prevalent among dog owners than among cat owners (p≤0.05). Overall, respondents have shown lack of knowledge about parasitic zoonoses. Results in the current study have evidenced the need of mediating and promoting information about potentially zoonotic parasitic agents among domestic pet owners, as well as the key role played by veterinarians as mediators of primary prevention measures against these agents.
Toxoplasmosis is a globally distributed zoonosis caused by Toxoplasma gondii. This protozoan is capable of infecting mammals and birds and can cause significant impacts on human and animal health. ...Much of what is known about the parasite’s biology, the immune mechanisms involved in toxoplasmosis, and the development of diagnostic tests for this protozoan disease is due to the maintenance of the parasite in laboratory mice. However, the increasing debate on the use of biomodels in scientific research has brought about the need to implement the principles of the 3Rs in laboratory protocols, such as experimental infections with T. gondii in murine models. Therefore, this study aimed to establish the humane endpoints for experimental infection with the T. gondii RH strain in Swiss Webster mice. The results presented here seek to disseminate the method we have proposed for the humane finalization of these animals in experimental protocols using this highly virulent strain as a method of refinement that seeks to enhance animal welfare. The highly virulent Toxoplasma gondii RH strain is maintained through successive passages in mice, but there is still a lack of studies that refine these procedures from a 3Rs perspective, where humanitarian ideals aim to minimize the stress, pain, or suffering of the animals used in the research without the loss of results. The aim of this study was to establish humane endpoints in Swiss Webster mice inoculated with the T. gondii RH strain. A total of 52 mice were infected with 5 × 10sup.6 tachyzoites/mL and monitored for periods of up to 5 days. The parameters body weight; hair condition; higher than normal body temperature; hypothermia; respiratory function; pain; soft stools or diarrhea; bloody diarrhea; tense, nervous, or in distress during handling; and ascites were recorded daily in score tables. The results showed that prominent piloerection, respiratory function, pain parameters, and ascites are important clinical signs to be used as a cut-off point for implementing euthanasia. The application of this refinement method helped to avoid animal suffering and pain without compromising the number of parasites recovered. We therefore suggest adopting these parameters in research protocols that require the maintenance of the T. gondii RH strain in murine models to avoid and reduce animal suffering.
