Toxoplasma gondii infection in sheep from Romania

Apigeninidin chloride disrupts Toxoplasma gondii Mitochondrial membrane potential and induce reactive oxygen species and metabolites production

Introduction

Apigeninidin chloride (APi) is a form of 3-deoxyanthrocyanidins (3-DAs) abundantly produced by the red Sorghum bicolor plant. It has been previously reported to be effective against Toxoplasma gondii (T. gondii) tachyzoites grown in vitro with less cytotoxic effect. However, its possible mechanism(s) of action has not been elucidated. Biochemically, we discovered that APi induced high reactive oxygen species (ROS) and mitochondria superoxide (MitoSOX) productions in tachyzoites, leading to mitochondrial membrane potential (MMP) disruption in vitro.

Methods

To confirm our biochemical results at the molecular level, we performed a liquid chromatography-mass spectrometry (LC-MS) analysis on APi-treated parasites to assess any metabolite and lipid alterations often associated with high ROS/MitoSOX production in cells.

Results

Noteworthy is that we detected several important oxidative stress-induced metabolites such as hexanal, aldehydes, methyl undeo10-enoate, butadiynyl phenyl ketone, 16-hydroxyhexadecanoic acid (16-OH, 16:0), 2-hydroxytricosanoic acid (C23:0; O), 3-oxodecanosanoic acid (C22:1; O), 2-hydroxypropylsterate, and furan fatty acids F6 (19FU-FA).

Discussion

These metabolites are associated with lipid, protein, and nucleic acid disruptions. Using atovaquone (Atov) as a control, we observed that it disrupted intracellular tachyzoites' mitochondrial membrane potential, increased ROS and MitoSOX production, and altered metabolite and lipid production similar to what was observed with our experimental compound APi. Overall, our results indicated that APi targets T. gondii tachyzoite growth through inducing oxidative stress, mitochondrial dysfunction, and eventually parasite death.

Cats as a sentinel species for human infectious diseases - toxoplasmosis, trichinellosis, and COVID-19

In this study, serological screening for Toxoplasma gondii, Trichinella spp., and SARS-CoV-2 in domestic cats was conducted, aiming to identify their exposure to the mentioned pathogens and to assess the risk of potential human infection. In total, serum samples from 481 (310 owned and 171 shelter cats) were collected in Bratislava from September 2020 to September 2021, a period that included the initial outbreak wave of the COVID-19 pandemic. The study showed a 37.4% (135/441) seroprevalence of T. gondii with a slightly lower seropositivity in shelter cats (35.9%; 61/170) than in owned cats (38.4%; 104/271), but this difference was not statistically significant. Overall, the seroprevalence of Trichinella spp. was 2.0% (9/441), with animals from shelters being positive but not significantly more often (2.9%; 5/170) than owned cats (1.5%; 4/271). SARS-CoV-2 antibodies were detected in 2.7% (13/481) of cat sera (2.9% in shelter cats; 2.6% in owned cats). Among ten samples positive by virus neutralisation assay, two were positive for the B.1 variant. The presence of the SARS-CoV-2 virus in buccal and rectal swabs (n = 239) was not detected. The seroprevalence of almost 40% for T. gondii in cats suggests a non-negligible risk of human infection. The study confirmed the possibility of Trichinella spp. infection in cats, and thus the possibility of infection spreading between the sylvatic and synanthropic cycle via this animal species. The presented results also showed that the SARS-CoV-2 virus is likely to circulate in cat populations in Slovakia, not only in cats that may have been in contact with infected persons, but also in shelter cats.

Detection of Toxoplasma gondii Infection in Small Ruminants: Old Problems, and Current Solutions

Toxoplasmosis is a parasitic zoonosis of veterinary importance, with implications for public health. Toxoplasma gondii infection causes abortion or congenital disease in small ruminants. Moreover, the consumption of infected meat, cured meat products, or unpasteurized milk and dairy products can facilitate zoonotic transmission. Serological studies conducted in various European countries have shown the high seroprevalence of specific anti-T. gondii antibodies in sheep and goats related to the presence of oocysts in the environment, as well as climatic conditions. This article presents the current status of the detection possibilities for T. gondii infection in small ruminants and their milk. Serological testing is considered the most practical method for diagnosing toxoplasmosis; therefore, many studies have shown that recombinant antigens as single proteins, mixtures of various antigens, or chimeric proteins can be successfully used as an alternative to Toxoplasma lysate antigens (TLA). Several assays based on DNA amplification have been developed as alternative diagnostic methods, which are especially useful when serodiagnosis is not possible, e.g., the detection of intrauterine T. gondii infection when the fetus is not immunocompetent. These techniques employ multicopy sequences highly conserved among different strains of T. gondii in conventional, nested, competitive, and quantitative reverse transcriptase-PCR.