Gut microbiota modulation by prednisolone in a rat kindling model of pentylenetetrazol (PTZ)-induced seizure.

The gut microbiota is a complex community composed by several microorganisms that interact in the maintenance of homeostasis and contribute to physiological processes, including brain function. The relationship of the taxonomic composition of the gut microbiota with neurological diseases such as autism, Parkinson's, Alzheimer's, anxiety, and depression is widely recognized. The immune system is an important intermediary between the gut microbiota and the central nervous system, being one of the communication routes of the gut-brain axis. Although the complexity of the relationship between inflammation and epilepsy has not yet been elucidated, inflammatory processes are similar in many ways to the consequences of dysbiosis and contribute to disease progression. This study aimed to analyze the taxonomic composition of the gut microbiota of rats treated with prednisolone in a kindling model of epilepsy. Male Wistar rats (90 days, n = 24) divided into four experimental groups: sodium chloride solution 0.9 g%, diazepam 2 mg/kg, prednisolone 1 mg/kg, and prednisolone 5 mg/kg administered intraperitoneally (i.p.) for 14 days. The kindling model was induced by pentylenetetrazole (PTZ) 25 mg/kg i.p. on alternate days. The taxonomic profile was established by applying metagenomic DNA sequencing. There was no change in alpha diversity, and the composition of the gut microbiota between prednisolone and diazepam was similar. The significant increase in Verrucomicrobia, Saccharibacteria, and Actinobacteria may be related to the protective activity against seizures and inflammatory processes that cause some cases of epilepsy. Further studies are needed to investigate the functional influence that these species have on epilepsy and the inflammatory processes that trigger it.

Immunization of Wistar female rats with 255-Gy-irradiated Toxoplasma gondii: Tissue parasitic load and lactogenic quantification.

Toxoplasma gondii is one of the most significant parasite, due its importance in veterinary medicine and in public health, considered a food-borne pathogens, there is no available drug treatments to eliminate it from animal tissue, this reinforce the search for a vaccine against this parasite. This study was aimed to evaluate the dynamic of the distribution of T. gondii in tissues of female Wistar rats and their milk, after the immunization by oral rote with irradiated tachyzoites. One week after pregnancy confirmation, rats was challenged by gavage with T. gondii bradyzoites, oocysts or tachyzoites of T. gondii. Forty-eight pregnant rats were grouped as follows: immunized and challenged with bradyzoites (BZ*); non-immunized and challenged with bradyzoites (BZ); immunized and challenged with oocysts (OC*); non-immunized and challenged with oocysts (OC); immunized and challenged with tachyzoites (TZ*); non-immunized and challenged with tachyzoites (TZ); only immunized (I); control group (C). After parturition, milk samples were collected for 3 weeks and then rats were sacrificed and the tissues and milk samples were researched for T. gondii parasite load determined by the quantitative PCR (qPCR). It was verified that the immunization with irradiated tachyzoites of T. gondii induced the reduction of parasitic load in muscle samples in rats challenged by bradyzoites and oocysts, although not enabled the development of sterile immunity. The detection of parasite DNA in milk was found throughout the lactation period, from immunized and non-immunized rats, however no differences were found in the parasite load caused by immunization.

Seropositivity of Anti-Toxoplasma gondii Antibodies in Owners and Their Dogs Living on Island and Mainland Seashore Areas of Southern Brazil.

Although toxoplasmosis has been considered among the most neglected zoonoses worldwide, no study has focused on the frequency and associated risk factors of owners and their dogs living on an island and mainland seashore areas. Accordingly, anti-Toxoplasma gondii IgG antibodies were screened by indirect fluorescent antibody test (IFAT) in owners and dogs from three oceanic islands and two nearby mainland harbor areas, with associated risk factors for toxoplasmosis assessed by univariable and multivariable logistic regression models. Overall, anti-T. gondii seropositivity was observed in 59/328 (18.0%) owners and 66/283 (23.3%) dogs, with no statistical difference between owners (p = 0.360) and dogs (p = 0.655) from islands and mainland areas. Consumption of local water springs (p = 0.016; OR = 2.11) was an associated risk factor for T. gondii seropositivity, and owners with the habit of spring water intake were twice more likely seropositive (p = 0.014; OR = 2.14). Presence of anti-T. gondii antibodies in dogs was associated with seropositive owners (p = 0.008; OR = 2.81), household consumption of beef meat (p = 0.042; OR = 1.7) and chicken (p = 0.026; OR = 2.9). Despite being lower than the worldwide prevalence, toxoplasmosis seropositivity in owners and their dogs in southern Brazil was influenced by the positive owner, water source, and meat consumption, and not by inhabiting islands or seashore mainland areas, presence of dogs, cats, or both. In addition, drinking water quality should always be considered a critical risk factor for toxoplasmosis on islands.

Ocorrência da infecção por Toxoplasma gondii pela detecção de anticorpos em galinhas-dangola criadas extensivamente no estado do Rio de Janeiro, Brasil

O presente estudo teve por objetivo avaliar a ocorrência de infecção por Toxoplasma gondii sugerida pela detecção de anticorpos específicos em galinhas-dangola criadas extensivamente no estado do Rio de Janeiro, Brasil. As aves foram oriundas de seis propriedades rurais: quatro no município de Maricá, uma no município de Silva Jardim e uma no município de Mangaratiba. Os soros das 114 galinhas-dangola adultas foram examinados pelo teste de aglutinação modificado (MAT) para detecção de anticorpos anti-T. gondii. Foram realizadas as diluições de 1:16, 1:64, 1:256, 1:1024 e 1:4096. Títulos iguais ou maiores que 16 foram considerados positivos. Foi encontrada uma ocorrência de 12,3% (14/114) de infecção por T. gondii em galinhas-dangola do estado do Rio de Janeiro. Três (50%) das seis propriedades estudadas apresentavam, pelo menos, uma galinha-dangola soropositiva para T. gondii. As ocorrências de galinhas-dangola soropositivas para T. gondii em cada município foram: seis (30%) das 20 aves examinadas em Mangaratiba, sete (10,9%) das 64 aves examinadas em Silva Jardim e uma (3,3%) das 30 aves examinadas em Maricá. Os títulos de anticorpos encontrados foram: 16 (42,9%), 64 (35,7%) e 256 (21,4%). Pela primeira vez no estado do Rio de Janeiro foi constatada a infecção por T. gondii em galinhas-dangola. Esse resultado indica contaminação ambiental com possibilidade de infecção hu