Toxoplasma gondii Genotypes and Feline: Geographical Distribution Trends
36 Pages Posted: 16 Sep 2018More...
Background: Toxoplasma gondii, an obligate intracellular protozoan parasite, is well-known for its ability to virtually infect all warm-blooded vertebrates. Felines are the only definitive hosts for this parasite playing an important role in the epidemiology of toxoplasmosis. Although cats are considered to be the definitive hosts, there are few descriptions of genetic diversity in the world. The present review study aimed to describe the population structure of T. gondii in these animal species.
Methods: For the purpose of the study, five English language databases reporting data on T. gondii genotyping in cats were searched within March-June 2017. The searching process resulted in the inclusion of 44 reports published from 1992 to June 2017.
Findings: The data revealed that 47,454 samples were genotyped into 615 T. gondii DNA/isolates. Globally, atypical genotypes were predominant (44%, n=270) and Type II clonal strains were the second most common genotype (39.6%, n=243). These results suggested an epidemic population structure in America and Asia, and a clonal population structure in Europe and Africa. Genotype #3 (also known as Type II variant) was found to be dominant in Africa, Europe, and Oceania continents. Furthermore, genotypes #9 and #5 (also known as Chinese 1 and Type 12, respectively) were prevalent in Asia and America, respectively. Additionally, genotypes #2, #3, #5, and #20 were common genotypes in domestic and sylvatic cycles from family Felidea.
Interpretation: Collectively, this systematic review indicated a large degree of genetic diversity and circulation of highly mouse virulent T. gondii strains in this family. However, further studies are necessary to better understand the population structures and determine the significance of their features.
Funding Statement: The authors declare: "There was no funding source for this study."
Declaration of Interests: The authors declare no competing interests.
Ethics Approval Statement: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline and checklist for the conduct of systematic review of cross-sectional studies 44 were followed (see S1 Checklist). The study protocol (15-Jan-2018) was registered on the site of CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility.
Keywords: Toxoplasma gondii, Genotype, Feline, Genetic Diversity, Continent
Suggested Citation: Suggested Citation