Toxoplasma gondii-Induced Long-Term Changes in the Upper Intestinal Microflora during the Chronic Stage of Infection

Abstract

Toxoplasma gondii is an obligate intracellular parasite with worldwide distribution. Felines are the definitive hosts supporting the complete life cycle of T. gondii. However, other warm-blooded animals such as rodents and humans can also be infected. Infection of such secondary hosts results in long-term infection characterized by the presence of tissue cysts in the brain and other organs. While it is known that T. gondii infection in rodents is associated with behavioral changes, the mechanisms behind these changes remain unclear. Alterations of the host intestinal microflora are recognized as a prominent role player in shaping host behavior and cognition. It has been shown that acute T. gondii infection of mice results in microflora changes as a result of gastrointestinal inflammation in inbred mouse models. The long-term effects of chronic T. gondii infection on microbial communities, however, are unknown. In this study, after we verified using our model in terms of measuring microflora changes during an acute episode of toxoplasmosis, we assessed the microbiome changes that occur during a long-term infection; then we further investigated these changes in a follow-up study of chronic infection. These analyses were performed by constructing and sequencing 16S rRNA amplicon DNA libraries from small intestine fecal specimens. We found that acute infection with the GT1 strain of T. gondii caused an enrichment of Bacteroidetes compared with controls in CD1 mice. Strikingly, this enrichment upheld throughout long-term chronic infection. The potential biological consequences of this alteration in rodents and humans should be subjected to further exploration.

Gut microbiota composition does not associate with toxoplasma infection in rats

“…Our results contrast with those of Shao et al (2020) and Prandovszky et al (2018), who reported substantial changes in the overall bacterial community composition in the gastrointestinal tract of mice chronically infected with Toxoplasma . These differences in results may be driven by the differing impacts of Toxoplasma infection in mice compared to rats and the implications infection has for sustained inflammation in each species.…”

The Gut Microbiome in Psychosis From Mice to Men: A Systematic Review of Preclinical and Clinical Studies

“…Infectious agents, such as Toxoplasma gondii, have been suggested to contribute to the development of schizophrenia (107,108). It has been recently demonstrated in a preclinical study that chronic Toxoplasma gondii infection results in an enrichment of Bacteroidetes in CD1 mice compared to noninfected controls (109). Interestingly, Bacteroidetes were also increased in a pharmacological model of schizophrenia (52) and in individuals with chronic schizophrenia (57).…”

Toxoplasma gondii α‐amylase deletion mutant is a promising vaccine against acute and chronic toxoplasmosis

“…Toxoplasma gondii ( T. gondii ), a vital obligate intracellular parasitic protozoan, is the causative agent of toxoplasmosis (Kato, 2018). The characteristics of it are worldwide distribution and broad host range that can infect all warm‐blooded animals including humans (Prandovszky et al ., 2018; Coutermarsh‐Ott, 2019). T. gondii is considered as a considerably successful parasitic organism, which can persist in the host for the host's entire lifetime and present opportunistic pathogenicity after successful infection (Dubey and Jones, 2008; Montazeri et al ., 2018a,b).…”