Prevalence and genetic diversity of Toxoplasma gondii oocysts in cats of southwest of Iran

Gastrointestinal parasites of cats in the Middle East (2000-2023): A literature review

BACKGROUND/OBJECTIVE

Gastrointestinal parasites in stray cats are of significant clinical and zoonotic importance and pose a potential threat to public health. Hence, the current review has practical implications as it aims to present the diversity and the prevalence of cat parasites in Middle Eastern countries.

METHODS

The research process was rigorous and thorough, spanning from 2000 to 2023. Data collection and analysis were conducted utilizing multiple international and national databases, including Google Scholar, Scopus, PubMed, and Irandoc. This meticulous approach ensures the reliability and validity of the findings, providing a solid foundation for further research and preventive measures.

RESULTS

A total of 159 articles were collected and comprehensively reviewed. Among these, 85 articles were from Iran, 25 from Türkiye, 20 from Iraq, 11 from Egypt, five from Qatar, three from Cyprus, three from Kuwait, and one each from the UAE, Saudi Arabia, Syria, Lebanon, Jordan, Israel, and Palestine. Toxocara cati was the most prevalent nematode, exhibiting the highest prevalence in Iran, ranging from 8% to 90%, followed by Egypt, with a range of 8.23% to 58.7%. In comparison, the lowest prevalence was recorded in Qatar at 8%. Hydatigera taeniaeformis, a common cestode in the feline, showed the highest prevalence in Qatar, with a range of 73.6% to 75.8%, while the lowest was in Kuwait at 0.8%. In Iran, the prevalence ranged from 0.9% to 64.7%. Toxoplasma gondii, a cosmopolitan protozoan, showcased the highest prevalence in Lebanon at 78.1% and the lowest in the UAE at 0.8%. In Iran, the prevalence ranged between 1.2% and 90%. Additionally, noteworthy patterns regarding the distribution and potential risk factors associated with these parasites were observed. While gender variations were not significant, environmental conditions such as high humidity and absence of sunlight exposure, along with the age and behavior of cats, were among the risk factors associated with the prevalence of parasites.

CONCLUSION

The prevalence of parasites among stray cats in Iran and other Middle Eastern countries remains notably high. This emphasizes the urgent need for a series of control and preventive measures. Implementing effective anti-parasitic strategies and emphasizing the development of multiple diagnostic methods are essential.

Prevalence and Molecular Characterization of Toxoplasma gondii and Toxocara cati Among Stray and Household Cats and Cat Owners in Tehran, Iran

Toxoplasma gondii and Toxocara spp. are the most critical parasites common between humans and cats. The close association of cats with humans in urban areas persuaded us to investigate the prevalence of these parasites in stray and household cats and their possible role in the owners' infection. Herein, 132 and 33 fecal samples of stray and household cats, respectively, and 33 blood samples of their owners were collected in Tehran, Iran. The prevalence of T. gondii was determined by targeting the B1 gene in the feces of stray and household cats and the blood of cat owners. Furthermore, genotypes of T. gondii were identified based on the multilocus genotyping of BTUB, GRA6, SAG3, and APICO loci. Toxocara spp. were detected by targeting the second internal transcribed spacer (ITS-2) of the ribosomal DNA of these parasites in the cats' feces and the humans' blood. Also, Toxocara IgG was assessed in the human serum samples. The B1 gene amplification showed that 15.2% of stray cats, 18.2% of household cats, and 51.5% of cat owners were infected with T. gondii. The multilocus sequence analysis revealed the predominance of genotype I of T. gondii in stray cats and genotype II of T. gondii in household cats and cat owners. The amplifying of ITS-2 revealed a high prevalence of T. cati infection (47.0%) in stray cats, whereas no infection was found in the feces of household cats or the serum of cat owners. Likewise, Toxocara IgG was not detected in the serum of humans. The lower prevalence of T. gondii in stray/household cats than in the cat owners indicates the limited impact of close contact with infected cats in human toxoplasmosis. However, the high prevalence of T. cati infection in stray cats can cause contamination of the environment by excreting eggs that may lead to infecting humans through soil or water. Therefore, public health education in urban management planning is necessary for routine urban cat deworming programs and for training the healthcare workers to prevent, control, and treat these infections.

Molecular Detection and Genetic Diversity of Toxoplasma gondii Oocysts in Cat Faeces from Klang Valley, Malaysia, Using B1 and REP Genes in 2018

The major route for Toxoplasma gondii (T. gondii) infection is through the ingestion of foods contaminated with oocyst from cat faeces. The microscopic detection of T. gondii oocysts in cat faeces is challenging, which contributes to the failure of detecting or differentiating it from other related coccidian parasites. This study aims to detect T. gondii oocysts in cat faeces using two multicopy-target PCR assays and to evaluate their genetic diversity. Cat faecal (200) samples were collected from pet cats (PCs; 100) and free-roaming cats (FRCs; 100) within Klang Valley, Malaysia, and screened for coccidian oocysts by microscopy using Sheather's sucrose floatation. PCR assays were performed on each faecal sample, targeting a B1 gene and a repetitive element (REP) gene to confirm T. gondii oocysts. Additionally, the PCR amplicons from the REP gene were sequenced to further confirm T. gondii-positive samples for phylogenetic analysis. Microscopy detected 7/200 (3.5%) T. gondii-like oocysts, while both the B1 gene and the REP gene detected 17/200 (8.5%) samples positive for T. gondii. All samples that were microscopically positive for T. gondii-like oocysts were also shown to be positive by both B1 and REP genes. The BLAST results sequenced for 16/200 (8.0%) PCR-positive T. gondii samples revealed homology and genetic heterogeneity with T. gondii strains in the GenBank, except for only one positive sample that did not show a result. There was almost perfect agreement (k = 0.145) between the two PCR assays targeting the B1 gene and the REP gene. This is the first report on microscopic, molecular detection and genetic diversity of T. gondii from cat faecal samples in Malaysia. In addition, the sensitivities of either the B1 gene or REP gene multicopy-target PCR assays are suitable for the accurate detection of T. gondii from cat faeces.