The cat is out of the bag: How parasites know their hosts

iTRAQ-Based Phosphoproteomic Analysis Exposes Molecular Changes in the Small Intestinal Epithelia of Cats after Toxoplasma gondii Infection

Toxoplasma gondii, an obligate intracellular parasite, has the ability to invade and proliferate within most nucleated cells. The invasion and destruction of host cells by T. gondii lead to significant changes in the cellular signal transduction network. One important post-translational modification (PTM) of proteins is phosphorylation/dephosphorylation, which plays a crucial role in cell signal transmission. In this study, we aimed to investigate how T. gondii regulates signal transduction in definitive host cells. We employed titanium dioxide (TiO2) affinity chromatography to enrich phosphopeptides in the small intestinal epithelia of cats at 10 days post-infection with the T. gondii Prugniuad (Pru) strain and quantified them using iTRAQ technology. A total of 4998 phosphopeptides, 3497 phosphorylation sites, and 1805 phosphoproteins were identified. Among the 705 differentially expressed phosphoproteins (DEPs), 68 were down-regulated and 637 were up-regulated. The bioinformatics analysis revealed that the DE phosphoproteins were involved in various cellular processes, including actin cytoskeleton reorganization, cell necroptosis, and MHC immune processes. Our findings confirm that T. gondii infection leads to extensive changes in the phosphorylation of proteins in the cat intestinal epithelial cells. The results of this study provide a theoretical foundation for understanding the interaction between T. gondii and its definitive host.

Gut microbiota differences induced by Toxoplasma gondii seropositivity in stray cats in South Korea

T. gondii is a highly prevalent parasite worldwide, with cats serving as its final host. However, few studies have investigated the impact of T. gondii infection on cat gut microbiota. Therefore, this study examined the influence of T. gondii infection on the gut microbiota of stray cats and identified potential pathogens in their feces. This study examined T. gondii infection through blood of stray cats and the influence of microbiota in their feces using 16S rRNA gene amplicon sequencing. The results revealed significant differences in gut microbiota composition and diversity between the T. gondii seropositive and seronegative groups. Seropositive samples displayed a lower number of operational taxonomic units and reduced Shannon index than the seronegative samples. The seropositive and seronegative groups exhibited enrichment of taxa, including Escherichia and Enterobacteriaceae and Collinsella, Bifidobacterium, and Roseburia, respectively. Furthermore, potential pathogen species, including Campylobacter, Escherichia, and Streptococcus, were identified in the fecal samples. These findings suggest that T. gondii infection significantly impacts gut microbiota composition and diversity in stray cats. Additionally, an increased potential pathogen load, represented by Escherichia spp., was observed. These results underscore the importance of monitoring the prevalence of zoonotic pathogens in stray cats, as they can serve as reservoirs for zoonotic diseases.

The anti-parasite action of imidazole derivatives likely involves oxidative stress but not HIF-1α signaling

BACKGROUND

Therapeutic options for toxoplasmosis are limited. This fact underscores ongoing research efforts to identify and develop better therapy. Previously, we reported the anti-parasitic potential of a new series of derivatives of imidazole.

OBJECTIVE

In the current investigation, we attempted the investigation of the possible action mechanism of few promising anti-parasite imidazole derivatives namely C1 (bis-imidazole), C2 (phenyl-substituted 1H-imidazole) and C3 (thiophene-imidazole) METHODS: We evaluated if oxidative stress, hypoxia as well as metabolic reprogramming of host l-tryptophan pathway form part of the parasite growth inhibition by imidazoles. Anti-parasite assay was performed for imidazoles at concentrations ranging from 0 to 10 μM, while pyrimethamine was used as reference drug to validate assay.

RESULTS

Imidazole compounds restricted parasite growth dose-dependently. However, in the presence of an antioxidant (Trolox), l-tryptophan and/or CoCl₂ (chemical inducer of hypoxia), the growth inhibitory efficacy of imidazoles was appreciably abolished. Further, imidazole treatment led to elevated level of reactive oxygen species, while reducing parasite mitochondrial membrane potential compared with control. In contrast, imidazole had no effect on host HIF-1α level suggesting its exclusion in the anti-parasite action.

CONCLUSION

Taken together, imidazole-based compounds might restrict parasite growth by causing oxidative stress. The findings provide new insight on the likely biochemical mechanisms of imidazoles as prospective anti-parasite therapy. Data gives new perspective that not only underscores the anti-parasite prospects of imidazoles, but implicates the host l-tryptophan pathway as a feasible treatment option for T. gondii infections.

A decreasing trend in toxoplasma gondii seroprevalence among pregnant women in Romania - results of a large scale study

Toxoplasmosis is a zoonotic infection caused by the obligate intracellular apicomplexan parasite Toxoplasma gondii (T. gondii). T. gondii infection is a cause of congenital infection worldwide. Primary infection or the reactivation of latent infection during pregnancy may lead to fetal infection and to congenital toxoplasmosis syndrome. Seropositive pregnant women are generally protected from maternal-fetal transmission of T. gondii, although exceptions exist. The aim of our study was to analyze the dynamics of T. gondii seroprevalence during a 10-year period and to correlate it with age and demographic features of pregnant women. We tested 6,889 pregnant women in Timisoara, Romania, for IgG-anti-T. gondii antibodies, in two successive periods: i) 2008-2010 (group 1: 1,457 participants); and ii) 2015-2018 (group 2: 5,432 participants). For each participant, data on age and area of residence were collected. Our results showed that in the Western Region of Romania T. gondii seroprevalence in pregnant women declined from 43.79 to 38.81% in the last ten years. This trend was observed in both urban (40.53 vs. 34.85%) and rural areas (52.22 vs. 46.22%). A higher seroprevalence rate was found in rural than in urban areas. In addition, we found an increasing tendency of seroprevalence related to the age of pregnant women.