Genetic characterization of Toxoplasma gondii in Iranian HIV positive patients using multilocus nested-PCR-RFLP method

Toxoplasma gondii in rodents and shrews in Armenia, Transcaucasia

Toxoplasma gondii infections in small mammals are important because they serve as source of infection for the felids who excrete environmentally resistant oocysts in their feces. Here, the authors sought evidence for T. gondii infection in shrews and rodents in Armenia for the first time. Toxoplasma gondii DNA was detected in tissues of trapped animals using a specific PCR targeting gene with a non-coding fragment length of 529 bp. Toxoplasma gondii DNA was detected in 15 out of 137 (10.9%) samples from small mammals from 6 different localities of Armenia for the first time.

Molecular detection and genotyping of Toxoplasma gondii in stray cat feces from Khorramabad, West Iran

Cats, being the definitive host of Toxoplasma gondii, have a significant impact on the spread and outbreaks of the parasite. An essential factor in comprehending the transmission pattern of this parasite is an analysis of the genetic diversity distribution in cats infected with T. gondii. This study was aimed at determining the prevalence rate and genotyping of T. gondii in stray cat feces from Khorramabad, West Iran. In the years 2016-2017, 200 cats were sampled to get fresh feces specimens. Parasitological methods were utilized for the identification of oocysts. The DNA was isolated from the feces using a commercially available Genomic Mini Kit. In order to identify the genetic composition of T. gondii, we employed PCR-RFLP, sequencing, and phylogenetic analysis of the GRA6 target gene. No one of the samples tested positive for parasitology techniques. A total of 6.5 % (13/200) samples were positive when using the GRA6-PCR method. Based on PCR-RFLP results, all 13 samples were of T. gondii type III genotype. The nucleotide sequences of two samples from this study were found to be 5 % different from those of 12 references of T. gondii and one strain of Hammondia hamondi that was used as an external control. Based on the findings, molecular tests are more sensitive than parasitological methods. The RFLP approach revealed that type III of T. gondii is the prevailing and important genotype in Khorramabad, West Iran.

Comparative GRA6 and GRA7 for their Utility as Genetic Markers in the Genotyping of Cerebral Toxoplasmosis in Cerebrospinal Fluid

INTRODUCTION

Cerebral toxoplasmosis is a severe symptom of Toxoplasma gondii (T. gondii) infection that often affects individuals with Human Immunodeficiency Virus (HIV) infection and can be fatal. T. gondii exhibits diverse strains with varied virulence, such as cerebral toxoplasmosis, which is connected with a specific strain. Molecular methods were used to investigate the genotype of the parasite. Some researchers have used genetic markers, such as the dense granule proteins GRA6 and GRA7, in order to identify T. gondii genotype. This study aimed to evaluate the applicability of GRA6 and GRA7 as genetic markers for determining T. gondii strain from cerebrospinal fluid of AIDS patients with toxoplasmic encephalitis.

METHOD

160 serum and cerebrospinal fluid (CSF) samples were collected from 2013 to 2022. The serum samples were initially tested using ELISA anti Toxoplasma IgG, and the CSF was subsequently PCR of 5'SAG2 gene for those positive IgG. A total of 69 CSF successfully positive on PCR of 5'SAG2 were included for analysis of GRA6 and GRA7 by performing PCR, sequencing and phylogenetic analysis for determination of T. gondii type.

RESULT

The findings of this study indicate that the use of GRA7 is better than GRA6 when using direct clinical samples. Out of the 69 samples analyzed, total of 36 samples (52.17%) were positive for GRA7. The cases can be classified as type I: 86,1% (31/36), type III: 2,7% (1/36) and atypical: 11,1% (4/36).

CONCLUSION

Comparison results between GRA6 and GRA7 for genotype determination shows good results on GRA7. GRA7 can be used as a genetic marker to find out the genotype of T. gondii in direct clinical samples where GRA6 cannot be used.

Association of polymorphism of IL-17A, IL-17F, and IL-6 with Toxoplasma gondii infection susceptibility in HIV/AIDS patients in Shiraz, southern Iran

INTRODUCTION

Toxoplasma gondii infection is considered as one of the most important opportunistic infections and cause of death in HIV patients.

METHODS

In this cross-sectional study, 334 HIV positive patients were included. The molecular test was performed by the restriction fragment length polymorphism-polymerase chain reaction method. Allelic frequency, haplotype analyses, and linkage disequilibrium were calculated. The odds ratio was calculated. The linear regression model was used to analysis of interleukin (IL)-17A, IL-17F, and IL-6 single-nucleotide polymorphism genotypes in HIV patients with and without toxoplasmosis.

RESULTS

In total, 95 tested'patients (28.4%) were positive for toxoplasmosis. The risk of toxoplasma infection in the current study did not correlate with IL-17 and IL-6 polymorphism and the risk of contracting toxoplasma was also not significantly correlated in this study. There was no association between the frequency of alleles and the risk of toxoplasma infection in IL-17 haplotype analysis.

CONCLUSION

The findings of this study revealed that there were significant differences in the serum levels of IL-6 and IL-17A, but not IL-17F, between the case and control groups in various genetic models. However, these polymorphisms did not show a significant relationship with toxoplasma infection in HIV-positive patients. This study represents the first investigation in Iran to explore the role of IL-6 and IL-17 polymorphisms in toxoplasma infection among HIV-positive patients.

Advances and Challenges in Diagnostics of Toxoplasmosis in HIV-Infected Patients

Toxoplasma gondii is a worldwide distributed protozoan parasite. This apicomplexan parasite infects one-third of the population worldwide, causing toxoplasmosis, considered one of the neglected parasitic infections. In healthy humans, most infections are asymptomatic. However, in immunocompromised patients, the course of the disease can be life-threatening. Human immunodeficiency virus (HIV)-infected patients have a very high burden of Toxoplasma gondii co-infection. Thus, it is essential to use modern, sensitive, and specific methods to properly monitor the course of toxoplasmosis in immunodeficient patients.

Prevalence of Toxoplasma gondii in HIV-Infected Individuals in Iran: A Systematic Review and Meta-Analysis

INTRODUCTION

Toxoplasma gondii is an obligate intracellular protozoan that can infect almost all warm-blooded animals, including humans. Patients with co-infection with toxoplasmosis and HIV have a 30-40% risk of developing toxoplasmosis encephalitis. This study aimed to describe the epidemiology and burden of Toxoplasma gondii in HIV-infected individuals in Iran.

METHODS

We searched the five English databases (Science Direct, PubMed, Scopus, Ovid, Embase, and Cochrane) and four Persian databases (Scientific Information Database (SID), Iran Medex, Iran Doc, and Magiran) with the terms of (Toxoplasma gondii OR "toxoplasmosis") AND (HIV OR "AIDS" OR immunodeficiency OR acquired immune deficiency syndrome) AND (Seroprevalence) AND (Seroepidemiologic Studies) AND (Elisa OR IgG) AND (PCR) AND (Iran) by two authors up to Feb 2021. Studies were included if they investigated people with HIV infection and presented data that allowed us to establish the prevalence of Toxoplasma gondii infection in Iran.

RESULTS

According to the inclusion/exclusion criteria, 15 studies were selected. A total number of 2275 HIV-infected individuals were tested and evaluated for toxoplasmosis from 2005 up to 2018 in different regions of Iran. The weighted overall prevalence of toxoplasmosis in HIV-infected individuals with Elisa was obtained using a random-effects model, which was estimated at 47% (95% CI = 31% - 62%). Also, the Weighted overall prevalence of toxoplasmosis in HIV-infected individuals with PCR was obtained using a random-effects model, which was estimated at 7% (95% CI = 3% - 12%).

CONCLUSION

According to the results of this study, it can be clearly understood that a large population of HIV patients living in Iran have toxoplasmosis. Therefore, due to the high susceptibility of these groups to toxoplasmosis, healthcare professionals must consider measures such as training in the ways of transmission and prevention of the infection to this high-risk group in order to reduce the risk of infection.

Identification and multilocus genotyping of Toxoplasma gondii isolates from congenital infection in north of Iran

Congenital toxoplasmosis can cause severe consequences in the fetus, such as spontaneous abortion which is affected by parasite strain. Also, recent studies revealed the high genetic diversity of Toxoplasma gondii. This study aims to investigate the serological status of T. gondii in pregnant women, multilocus genotyping in aborted fetuses' tissue, and archived formalin-fixed paraffin-embedded placenta. This study was performed on 100 pregnant women with spontaneous abortion and their aborted fetuses, and 250 of the archived placentae in Iran. The blood and tissue were examined for seroprevalence and genotype determination of T. gondii using ELISA and multilocus nested-PCR-RFLP, respectively. Anti-T. gondii IgG and IgM were detected in 68 samples (68%) and 1 (1%) out of 100 serums. Toxoplasma DNA was identified in 1 (1%) aborted fetuses' tissue and 32 (12.8%) placenta samples. Overall, ten positive DNA samples were successfully genotyped, and five genotypes were recognized (ToxoDB#1, #2, #10, #27, and #48). The obtained results indicated congenital toxoplasmosis is a severe risk in this region. As type I is highly pathogen and can lead to severe complications, the prevention of the infection should be considered in seronegative pregnant women.

Genetic characterization of Toxoplasma gondii in meat-producing animals in Iran

BACKGROUND

The consumption of uncooked or undercooked food from infected intermediate hosts can result in Toxoplasma gondii infection in humans. However, few studies have investigated the genetic diversity of this protozoan parasite in Iran. The aim of the present study was to genetically characterize isolates of T. gondii from intermediate host animals in Mazandaran Province, Iran.

METHODS

Blood and heart tissue samples were collected from 204 ruminants, and brain tissue was collected from 335 birds. The prevalence of T. gondii infection in these samples was determined serologically using the modified agglutination test and by conventional PCR assays. Those PCR samples positive for T. gondii DNA and 13 DNA samples extracted from aborted fetuses in a previous study were genotyped with 12 genetic markers using the multilocus-nested PCR-restriction fragment length polymorphism (Mn-PCR-RFLP) technique.

RESULTS

Antibodies for parasites were found in 35.7% of the ruminant (39.1% of sheep and 26.4% of goats) samples and in 51.3% of the bird (100% of geese, 52.3% of free-range chickens and 46% of ducks) samples. Molecular detection by PCR of the repetitive 529-bp DNA fragment revealed contamination of 13.2% of ruminant (14.6% of sheep and 9.4% of goats) samples and of 9.6% of bird (11.1% of chickens, 5.7% of ducks and 0% of geese samples). The results from 30 DNA samples revealed five ToxoDB (genome database for the genus Toxoplasma) PCR-RFLP genotypes, including #1 (Type II), #2 (Type III), #10 (Type I), #27 and #48, with genotype #1 the most predominant.

CONCLUSIONS

As evidenced by the results of this study, ruminants and birds are infected with T. gondii in the region, suggesting that they are likely to be involved in the transmission of T. gondii to humans through meat consumption. The identification of different genotypes may suggest a higher genetic diversity of this parasite in Mazandaran, reflecting local environmental contamination. These results have important public health implications for the prevention and control strategies of infection.

Toxoplasmosis among cancer patients undergoing chemotherapy: a population study based on the serological, molecular and epidemiological aspects

BACKGROUND

Toxoplasmosis is highly prevalent in northern Iran and immunocompromised individuals are more susceptible to this infection. The present study aimed to determine the seroprevalence, parasitism and genetic diversity of Toxoplasma gondii among patients with cancer undergoing chemotherapy in northern Iran.

METHODS

A total of 350 serum samples obtained from cancer patients were collected from laboratory centers in northern Iran. Immunodiagnosis and DNA detection were accomplished by ELISA and PCR. Thereafter, multiplex-nested PCR-restriction fragment length polymorphism was used for the genotyping of T. gondii.

RESULTS

In general, out of 350 patients, 264 (75.4%) and 9 (2.57%) cases were positive for anti-T. gondii IgG and IgM, respectively. Moreover, 19 (5.43%) samples contained T. gondii DNA. From 19 positive samples, 10 high-quality samples with sharp and non-smear bands were selected to determine the genotypes of T. gondii. Accordingly, the samples were classified as genotype #1 (type II clonal; n=4, 40%), genotype #2 (type III clonal; n=3, 30%), genotype #10 (type I clonal; n=2, 20%) and genotype #27 (type I variant; n=1, 10%).

CONCLUSIONS

As evidenced by the results, due to the high prevalence of T. gondii, cancer patients in northern Iran are at serious risk of severe toxoplasmosis and its complications. Therefore, oncologists need to regard this critical health problem as a matter requiring urgent attention.