Intracellular Protozoan Research Articles

Toxoplasma gondii Prevalence and Risk Factors among Female Students at Al-Yemenia University, Sana'a City, Yemen

Abstract Background: Toxoplasmosis is one of the most common human infections worldwide. It is caused by the intracellular protozoan Toxoplasma gondii. Therefore, this study aimed to determine the prevalence of Toxoplasma gondii infection among female students at Al-Yemenia University in Yemen. Methods: Two hundred female students were selected for this study and screened for Toxoplasma gondii antibodies using an immunochromatographic technique (ICT). Demographic, socioeconomic, risk factors, and behavioral data were collected using a pre-tested questionnaire via face-to-face interviews. Results: The seropositivity rate for T. gondii was (6.0%). The majority were from age groups of 18–20 and 21–24 years (41.7%), who lived in the urban area (83.3%), unmarried individuals (83.8%), and middle-income participants (66.7%), with a non-significant difference (P < 0.05). Female students who washed vegetables before eating had a high risk of T. gondii infection (OR = 4.810), followed by raising cats in the house (OR = 3.812), and had a history of blood transfusion (OR = 1.618). Conclusion: This study reported low seroprevalence among female students at Al-Yemenia University, Yemen. Environmental sanitation, personal hygiene, and health education are all required for promotion to prevent Toxoplasma gondii infection among female students.

Seroepidemiological study of Neospora caninum in equids using c-ELISA in Erbil Province, Iraq.

Equine neosporosis is an intracellular protozoan disease with a global distribution, affecting a diverse range of warm-blooded animals. Neospora caninum Dubey, Carpenter, Speer, Topper et Uggla, 1988 is associated with foetal loss, neurological disease and abortion in equids. No information was available regarding equine N. caninum infection among equids in Iraq. Thus, the aim of this study was to determine the prevalence rate of N. caninum in equines by using a competitive enzyme-linked immunosorbent assay (c-ELISA). A total of 329 blood samples randomly selected from equines, comprising 268 horses and 61 donkeys were examined. The seroprevalence rate of N. caninum was determined as 46% (28/61) for donkeys and 24% (64/268) for horses. The prevalence of N. caninum indicated a significantly higher risk of infection in donkeys compared to horses (P < 0.001). However, the odds of N. caninum infection in draught equids were 8.2 times greater than other equids with a significant difference (P < 0.001). The current study revealed no significant differences in the prevalence of N. caninum across various genders, breeds, clinical statuses, disease histories and among equids that had contact with dogs. While outdoor feeding and mixed (grazing), showed a significant difference (P = 0.003) and (P = 0.75), respectively, in the presence of antibodies against N. caninum compared to indoor feeding (stable). Moreover, the odds of infection in equids with a history of late abortion were 4.8 times higher than those without such a history of abortion (2.20-10.56) with statistical significance (P < 0.001).

Analysis of the Correlation Between Toxoplasma gondii Seropositivity and Alzheimer's Disease.

Alzheimer's disease (AD) is a multifactorial brain disorder and infectious diseases are considered as one of the predisposing factors for AD. Toxoplasma gondii, an obligate intracellular parasitic protozoan, is suspected of being associated with AD. Serum samples were collected from 109 AD patients and 114 age-matched healthy controls. ELISA was performed using recombinant T. gondii cyst wall protein 1 (CST1) to detect T. gondii antibodies. A parallel experiment was performed with Toxoplasma gondii tachyzoites lysate protein. To analyze whether factors associated with the onset of AD included chronic T. gondii infection, a multivariate logistic regression model was applied, further validating the correlation between chronic T. gondii infection and AD. AD patients exhibited significantly higher levels of Toxoplasma-specific antibodies in their serum compared to the control group, with statistically significant differences (p < 0.05). Multivariate logistic regression analysis revealed that Toxoplasma infection is a risk factor for AD (p < 0.01), and the CST1 antigen can significantly improve the model's performance in predicting the occurrence of AD. The results indicate that chronic infection with Toxoplasma gondii could be one of the risk factors for the development of AD, potentially predisposing individuals with underlying health conditions to the disease. This further validates the correlation between Toxoplasma gondii and AD.

Seroprevalence and Distribution of Toxoplasma gondii Infections among Patients in the West Bank, Palestine (2017-2021).

Toxoplasmosis is a zoonotic disease caused by the obligate intracellular protozoan Toxoplasma gondii. The current study assessed the seroepidemiological status and risk factors of T. gondii in the West Bank, Palestine. We conducted a retrospective study among 1,475 patients referred for serological examination for toxoplasmosis between 2017 and 2021 at the Central Public Health Laboratory. The overall prevalences of anti-T. gondii IgG and IgM antibodies were 1.0% [18.9-23.0%] and 1.0% [0.5-1.6%], respectively. Multifactorial analysis showed that age and sex were significantly associated with the presence of IgG antibodies. The prevalence of IgG antibodies was highest in 2018 and decreased significantly each year until 2021. Routine serological screening in women of childbearing age and pregnant women is recommended.

Seroprevalence of Toxoplasma gondii in Cattle in Southern Egypt: Do Milk and Serum Samples Tell the Same Story?

Toxoplasma gondii is an intracellular protozoan parasite of veterinary and public health importance. Infection may lead to abortion in susceptible pregnant animals and women, and potentially fatal health complications in immunocompromised individuals. In this study, we aimed to provide an update on the seroprevalence of, and risk factors for, T. gondii antibodies in cattle from Qena, southern Egypt. Additionally, we investigated if raw milk and serum samples from the same animals reacted similarly in a commercial ELISA, thus potentially reducing the invasiveness of future serosurveillance studies. Cattle serum samples (n = 362) from three locations in the Qena governorate (Qena, Qus, and Al Waqf cities), of both sexes and different ages were collected. From most dairy cows, a corresponding milk sample (n = 154) was additionally obtained. We found that the overall seroprevalence in serum samples was 9.1% (33/362). Increasing age was the sole risk factor identified in our study among all tested parameters (location, age, sex, lactating yes or no). Thus, older cattle (more than 3 years old) exhibited significantly higher rates of T. gondii antibodies (11.7%; p = 0.033, odd ratio = 4.3) in comparison to animals younger than 1 year (2.9%). In the corresponding serum and milk samples, the prevalence was 12.3% (19/154) in serum samples, and 9.7% (15/154) in milk samples, respectively. A high correlation was observed between the two sample types with a concordance of 97.4%, a kappa value of 0.87, and a Pearson r correlation coefficient of 0.85. When the serum ELISA was taken as the gold standard, the milk ELISA had the following characteristics: sensitivity (78.9%), specificity (100%), positive predictive value (100%), negative predictive value (97.1%), and area under the receiver operating characteristic (ROC) curve (0.6, p = 0.0011). In this study, we confirmed the frequent occurrence of T. gondii antibodies in cattle in southern Egypt and demonstrated that non-invasive milk samples may be used instead of serum samples for seroprevalence studies in dairy cows.

A Retrospective Analysis of Human Cutaneous Leishmaniasis Epidemiology During 2016 - 2021 in Hoveyzeh County, Khuzestan Province, Iran

Background: Leishmaniasis, a significant neglected tropical disease, is caused by obligate intracellular protozoa of the Leishmania genus. Objectives: This research aimed to investigate the epidemiology of cutaneous leishmaniasis (CL) from 2016 to 2021 in Hoveyzeh county. Methods: This study is a retrospective, cross-sectional, descriptive study based on available data. The study population included all individuals treated and followed up in health care centers who were clinically diagnosed with CL and confirmed by laboratory tests. Results: Among the 628 individuals diagnosed with CL, 324 (51.6%) were male, and 304 (48.4%) were female. The average age of the patients was 16.58 ± 15.17 years. The highest proportion (45.4%) of cases occurred in the 0 - 10-year age group, highlighting the vulnerability of children, while those above 50 years had the lowest incidence (3.7%). Approximately 68.2% of patients resided in urban areas, with the remainder living in rural settings. The hand was the most frequently affected area (44.5%), and the maximum number of lesions reported in a single individual was 25. Most patients (46.82%) were treated with topical glucantime along with cryotherapy. Disease incidence showed seasonal variation, with the highest number of cases reported in autumn (54%) and a significant peak in December (22%). The highest incidence year was 2016 (30.3%). Conclusions: Effective strategies to combat this disease should include comprehensive public awareness campaigns focused on health education, early recognition of symptoms, and transmission methods. Promoting personal protective measures is crucial for disease prevention efforts.

Coinfection of Toxoplasma gondii and Other Microorganisms: A Systematic Review and Meta-Analysis.

Toxoplasmosis is a disease caused by the intracellular protozoan Toxoplasma gondii, which has infected a third of the global population. Immunocompromised individuals and children with congenital disorders are most likely to be impacted by toxoplasmosis, and accurate diagnosis is essential. Toxoplasmosis is associated with HIV, schizophrenia, and diabetes. However, few studies have analyzed the association with other microorganisms. The purpose of this study was to determine the prevalence of coinfection of Toxoplasma gondii with other pathogens. From November 1997 to June 2024, PubMed, Science Direct, LAT index, Web of Science, Google Scholar, and Research Gate were searched. The keywords used were "Toxoplasma and microorganism coinfection", "Toxoplasma coinfection and parasites", "Toxoplasma coinfection and Protozoans or Bacteria or Helminths or Nematodes or Trematodes or Mycobacterium", "Toxoplasma gondii in coinfection with virus", and "Human Toxoplasmosis and coinfection". Next, OpenMeta Analyst Software version 12.11 was used for meta-analysis, creating forest plots, and determining heterogeneity I2. A total of 17,535 patients in 48 articles, of whom 5848 were seropositive to T. gondii, were included in this review. Population studies showed that the prevalence of virus infection was most frequent (32%), followed by parasites (18.4%), bacteria (29.7%), and fungi (5.8%). The pooled prevalence of coinfection was found to be 29.1%, with a lower bound of 0.232, an upper bound of 0.350, a standard error of 0.030, and p < 0.001. Heterogeneity (I2) was 99.12%, p < 0.001, with a global variance tau2 = 0.042. Toxoplasma gondii is an opportunist that mainly affects immunocompromised populations. The main coinfections were found to be viral infections, with HIV ranking first, followed by cytomegalovirus, hepatitis B and C, rubella, herpes simplex 1 and 2, SARS-CoV-2, and coxsackie virus.

The association of serum level and polymorphisms of IFN-γ (rs2069705) with the susceptibility to cutaneous leishmaniasis

Leishmaniasis, a broad range of parasitic diseases, caused by Leishmania which is a flagellated intracellular protozoan parasite of the family Trypanosomatidae. The severity of leishmaniasis diseases ranges from minor cutaneous lesions to severe visceral illnesses that can be disfiguring and life-threatening. Cytokines are glycoprotein molecules produced by various cells in response to various immunological triggers. They regulate the body’s innate and adaptive immunological responses. The aim of this study was to clarify the association of serum level and polymorphisms of IFN-γ with susceptibility to cutaneous leishmaniasis (CL). The whole blood 200 samples were collected from patients and controls from Diyala Governorate/ Iraq from October 2022 to February 2023 which were used to measure IFN-γ polymorphisms using High Resolution Melting technique. Enzyme-linked immunosorbent assay was used to detect the serum level of IFN-γ. The findings of this investigation showed that the IFN-γ serum concentration elevated significantly in patients compared to controls (P < 0.01). Also, the study found that the highest mean level IFN-γ concentrations were found in adults aged 46–55 years old for patients compared with controls with significant differences (P < 0.01). While, no significant differences were observed in the rest age groups except children aged 5–15 years old. Additionally, significant differences between patients and controls were revealed by polymorphisms data in all genetic models for genotypes GA, AA, (GA + AA) and allele A with (P < 0.01) and OR > 1. However, the distribution of IFN-γ serum levels by SNP (rs2069705) demonstrated no differences between genotypes except GG genotype which has significant differences for patients comparing to the same genotype in controls. Taking together, the SNP for IFN-γ (rs2069705) could be a risk factor for susceptibility infection with CL. Also, considered the mutant allele A as a risk allele and genotype AA in codominant genetic model as more risk factor than the genotype GA.

First Molecular Identification and Prevalence of Sarcocystis spp. in Sheep Intended for Human Consumption in Shanxi Province, China.

Sarcocystis species are intracellular coccidian protozoans that can infect a range of animals and humans and cause public health problems and economically significant losses. Sarcocystosis in sheep (Ovis aries) can cause abortion, neurological symptoms, and even death and results in significant economic losses to the livestock industry. To date, however, it is yet unknown whether sheep in Shanxi Province, north China, are infected with Sarcocystis spp. The purpose of this study was to investigate the prevalence of Sarcocystis spp. in sheep in Shanxi Province. Thus, 582 muscle samples of sheep were purchased from farmers' markets from ten representative counties in Shanxi Province, north China, and examined for the presence and prevalence of Sarcocystis spp. by PCR amplification of the mitochondrial cytochrome c oxidase subunit I (cox1) gene. Of the examined 582 mutton samples, 197 samples (33.85%) were Sarcocystis-positive and were sequenced. Of the obtained 197 cox1 sequences, 196 sequences showed nucleotide similarity of 98.56-99.81% with those of S. tenella, and the remaining one cox1 sequence showed nucleotide similarity of 99.71% with that of S. arieticanis. Two representative cox1 sequences of S. tenella (accession nos. PQ189447 and PQ189448) have 99.52% and 99.61% identity with S. tenalla (KC209725) and S. tenalla (MK419984), respectively. The sequence of S. arieticanis (accession no. PQ165949) obtained in this study has 99.71% identity with S. arieticanis (MK419975). This present study documents the occurrence and prevalence of Sarcocystis spp. in sheep in Shanxi Province for the first time, which enriches the data on the distribution of Sarcocystis spp. in sheep in China and has implications for the control of sheep sarcocystosis.

Organellar genome dynamics of exogenous stages of Eimeria tenella

BackgroundCoccidia are a group of intracellular protozoal parasites within the phylum Apicomplexa. Eimeria tenella, one of the species that cause intestinal coccidiosis in poultry, can cause significant mortality and morbidity. Diploid oocysts of Eimeria species are shed in the feces of an infected host and must sporulate to achieve infectivity. This process results in eight haploid infectious units, called sporozoites, held within a single oocyst. Each Eimeria spp. parasite possesses a single apicoplast and a single mitochondrion, both of which carry multiple copies of their respective organellar genomes. Reports of copy numbers of organellar genomes have varied widely.MethodsWe report the application of quantitative polymerase chain reaction (qPCR), supported by next-generation sequencing, for the quantification of the extranuclear genomes relative to the nuclear genome over the course of sporulation and following its completion.ResultsAt 64 elapsed hours, 93.0% of oocysts were fully sporulated; no increase in percent sporulation was observed after this time. Apicoplast relative genome copy number showed several significant shifts up to 72 elapsed hours, after which no significant shifts were observed. Oocysts were shed with approximately 60% the amount of apicoplast DNA present at 72 h, after which point no significant shifts in apicoplast genome relative abundance occurred. Mitogenome relative copy number showed only two significant shifts, from 16 to 24 elapsed hours and from 24 to 32 elapsed hours. Oocysts were shed with approximately 28% the amount of mitochondrial DNA that was present at the time sporulation was deemed morphologically complete, at 64 elapsed hours.ConclusionsThe characterization of the dynamics of genome abundance in exogenous stages sheds new light on the basic biology of Eimeria spp. and supports the use of extranuclear targets for molecular modes of parasite quantification and identification with improved sensitivity and accuracy.Graphical

A Comprehensive Bibliometric Analysis of Research Trends About Congenital Toxoplasmosis.

Toxoplasma gondii is an obligate intracellular protozoon that infects approximately one-third of the human population. The parasite could transmit from mother to fetus in cases of acute infection during pregnancy and cause complications in the fetus. The bibliometric analysis is a popular research area that evaluates all the studies indexed in particular databases on a subject. This article puts forth bibliometric review of the literature on maternal and congenital toxoplasmosis research indexed in the Web of Science database between 1945 and 2024. VOS viewer, Web of Science and MS Office Excel 17 programs were used in the study. The results of the search showed 1476 publications. The countries that most contributed to the literature were France (n=306, 20.73%), the USA (n=229, 15.52%), and Brazil (n=146, 9.89%). The most cited country was also France (n=10271, 35.52%), followed by the USA (n=9113, 31.51%), and England (n=2611, 9.03%). The top three countries by number of citations per document were Denmark (44.88), the USA (39.79) and France (33.57). The five departments with the most publications are Pediatrics (20.26%), General Internal Medicine (18.16%), Infectious Diseases (16.8%), Obstetrics (14.57%), and Immunology (11.86%). Wallon M. (n=57), Peyron F. (n=49), Thulliez P. (n=36) and Vilena I. (n=36) were the leading authors in terms of contribution to the literature. The five most published journals were Pediatric Infectious Disease Journal (3.66%), Journal of Clinical Microbiology (2.78%), Lancet (2.3%), Presse Medicale (1.76%), and American Journal of Obstetrics and Gynecology (1.63%). France is one of the countries that pays the most attention to congenital toxoplasmosis and compatible with this, in our study, the country with the highest number of studies on congenital toxoplasmosis was France. It is thought that drawing more attention to this issue and conducting more studies in countries where the disease is common might yield successful results, as in France.

The emerging role of Toxoplasma gondii in periodontal diseases and underlying mechanisms.

Toxoplasma gondii (T. gondii), an obligate intracellular protozoan parasite, is increasingly recognized for its role in various human diseases, including periodontal diseases. Periodontal diseases comprise a wide range of inflammatory conditions that not only affect the supporting structures of the teeth and oral health but also contribute to systemic diseases. The parasite's ability to modulate the host's immune response and induce chronic inflammation within the periodontium is a key factor in periodontal tissue damage. Through its virulence factors, T. gondii disrupts the balance of inflammatory cytokines, leading to dysregulated immune responses, and exacerbates oxidative stress in periodontal tissues. And T. gondii invasion could affect specific proteins in host cells including HSP70, BAGs, MICs, ROPs, SAGs, and GRAs leading to periodontal tissue damage. The indirect role of the host immune response to T. gondii via natural killer cells, monocytes, macrophages, neutrophils, dendritic cells, T cells, and B cells also contributes to periodontal diseases. Understanding these complex interactions of T. gondii with host cells could unravel disease mechanisms and therapeutic targets for periodontal diseases. This review delves into the pathogenic mechanisms of T. gondii in periodontal diseases, offering a detailed exploration of both direct and indirect pathways of its impact on periodontal health.

Eimeria tenella rhoptry neck protein 2 plays a key role in the process of invading the host intestinal epithelium

The Apicomplexa parasitic phylum rhoptry neck protein 2 (RON2) plays a key role in the process of invading host cells. Eimeria tenella, an intracellular protozoan shares a similar conserved invasion pattern. However, whether E. tenella RON2 participates in the process of invading the host intestinal epithelium is poorly understood. In this study, the sequence of EtRON2 was analyzed and expressed. The expression of the truncated extracellular N-terminal fragment of EtRON2 (403–700 aa, designated EtRON2403–700) with a molecular mass of 38.3 kDa. EtRON2 in the sporozoite protein was detected at 151.4 kDa by rabbit anti-rEtRON2403–700 antibody. Immunofluorescence results showed that EtRON2 was mainly localized to the nucleus and apex of the E. tenella sporozoite. qPCR results showed that the highest expression level of EtRON2 was detected in sporulated oocysts compared with other developmental stages of E. tenella. In vitro invasion inhibition assays showed that the capacity of sporozoites to invade DF-1 cells was significantly inhibited after pretreatment with the rabbit anti-rEtRON2403–700 antibody. Silencing the EtRON2 gene by RNA interference (RNAi) significantly inhibited EtRON2 expression and significantly reduced the invasion of DF-1 cells by sporozoites. In vivo experiments revealed a significant decrease parasite burden and oocyst outputs in chicks after infection with EtRON2 gene-silenced sporozoites by cloacal inoculation. Recombinant EtRON2403–700 (rEtRON2403–700) immunizes chicks effectively against E. tenella infection by inducing humoral immunity and upregulating IFN-γ and CD8+ T lymphocytes. Furthermore, chicks exhibited increased relative weight gain rates, lower cecum lesion scores, and reduced oocyst outputs during the E. tenella challenge. H&E staining showed that the cecum tissue of chicks immunized with rEtRON2403–700 showed relatively mild histopathological changes. In conclusion, the results of this study demonstrated that EtRON2 plays a key role in E. tenella invasion of the host intestinal epithelium and provides a potential target for vaccines against E. tenella infection.

Toxoplasma-induced behavior changes - is microbial dysbiosis the missing link?

Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoa in that it can infect the majority of mammalian cell types during the acute phase of infection. Furthermore, it is able to establish a chronic infection for the host's entire lifespan by developing an encysted parasite form, primarily in the muscles and brain of the host, to avoid the host immune system. The infection affects one third of the world population and poses an increased risk for people with a suppressed immune system. Despite the dormant characteristics of chronic T. gondii infection, there is much evidence suggesting that this infection leads to specific behavior changes in both humans and rodents. Although numerous hypotheses have been put forth, the exact mechanisms underlying these behavior changes have yet to be understood. In recent years, several studies revealed a strong connection between the gut microbiome and the different organ systems that are affected in T. gondii infection. While it is widely studied and accepted that acute T. gondii infection can lead to a dramatic disruption of the host's normal, well-balanced microbial ecosystem (microbial dysbiosis), changes in the gut microbiome during the chronic stage of infection has not been well characterized. This review is intended to briefly inspect the different hypotheses that attempt to explain the behavior changes during T. gondii infection. Furthermore, this review proposes to consider the potential link between gut microbial dysbiosis, and behavior changes in T. gondii infection as a novel way to describe the underlying mechanism.

Integrated subtractive genomics and structure-based approach to unravel the therapeutic drug target of Leishmania species.

Leishmaniasis is a complex vector-borne disease caused by intracellular protozoan parasites of the Leishmania genus. It presents a significant public health challenge in tropical and subtropical regions globally. As resistance to treatment increases, managing and controlling Leishmaniasis becomes more challenging, necessitating innovative approaches. To address this challenge, our study utilized subtractive genomics and structure-based approaches to identify common drug targets and combat antimicrobial resistance (AMR) across five Leishmania species strains. The subtractive genomics approach unraveled Glutamate Dehydrogenase (GDH) as a promising drug target for treating Leishmania infections. The investigation considered established methodologies observed in analogous studies, orthologous group, and druggability tests. Multiple sequence alignment revealed conserved sequences in GDH, while phylogenetic tree analysis provided insights into the evolutionary origin and close relationships of GDH across Leishmania species. Conserved sequences in GDH along with its function in pathogenicity provided insights into the close relationships of GDH across Leishmania species. Using a structure-based approach, our study showed the molecular interactions between GDH and three ligands-Bithionol, GW5074, and Hexachlorophene-through molecular docking and 100ns molecular dynamics (MD) simulations. GW5074 exhibited a significant affinity for GDH, as indicated by stable RMSD values, a more compact conformation, and a higher number of hydrogen bonds than Bithionol. MMPBSA analysis confirmed the superior binding energy of the GW5074-GDH complex, emphasizing its potential as a potent ligand for drug development. This comprehensive analysis identified GW5074 as a promising candidate for inhibiting GDH activities in Leishmania species, contributing to the development of effective therapeutics against Leishmania infections.

Live-attenuated PruΔgra72 strain of Toxoplasma gondii induces strong protective immunity against acute and chronic toxoplasmosis in mice

BackgroundToxoplasma gondii is an intracellular opportunistic pathogenic protozoan that poses serious threats, particularly in immunocompromised individuals. In the absence of a robust prophylactic measure, the mitigation and management of toxoplasmosis present formidable challenges to public health. We recently found that GRA72 plays an important role in parasitophorous vacuole (PV) morphology, growth and virulence of T. gondii. However, whether gra72-deficient strain can be used as a vaccine remains unknown.MethodsWe first examined the attenuated virulence of gra72 gene knockout strain (PruΔgra72) and the parasite load in organs of the infected mice. Subsequently, we evaluated the immune-protective effects of the PruΔgra72 vaccination against challenge with various types of T. gondii tachyzoites and Pru cysts. Furthermore, levels of antibodies and cytokines induced by PruΔgra72 vaccination were examined. Statistical analysis was conducted by Student’s t-test or Mantel-Cox log-rank test based on data obtained from three independent experiments with GraphPad Prism 8.0.ResultsWe found that PruΔgra72 strain exhibited a significantly attenuated virulence even at the highest dose of 5 × 107 tachyzoites in Kunming mice model. The significant decrease of brain cyst burden and parasite load in the organs of the PruΔgra72-infected mice suggested its potentiality as a live-attenuated vaccine. Hence, we explored the protective immunity of PruΔgra72 vaccination against toxoplasmosis. Results showed that vaccination with 5 × 106 PruΔgra72 tachyzoites triggered a strong and sustained Th1-biased immune response, marked by significantly increased levels of anti-T. gondii IgG antibodies, and significantly higher levels of Th1 type cytokines (IL-2, IL-12 and IFN-γ) compared to that of Th2 type (IL-4 and IL-10). Vaccination with 5 × 106 PruΔgra72 tachyzoites in mice conferred long-term protection against T. gondii infection by less virulent tachyzoites (ToxoDB#9 PYS and Pru strains) and Pru cysts, provided partial protection against acute infection by high virulent Type I RH tachyzoites and significantly decreased brain cyst burden of chronically infected mice.ConclusionsThe avirulent PruΔgra72 induced strong protective immunity against acute and chronic T. gondii infection and is a promising candidate for developing a safe and effective live-attenuated vaccine against T. gondii infection.Graphical

МИКРОСПОРИДИИ ИЛИ КЛЕТКИ ПАНЕТА? ОСОБЕННОСТИ ДИАГНОСТИКИ МИКРОСПОРИДИОЗА ЧЕЛОВЕКА ПО ГИСТОСРЕЗАМ КИШЕЧНИКА

The Clinical Diagnostic Laboratory of Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, I.M. Sechenov First Moscow State Medical University continues to share its experience in diagnosing rare, unusual and/or ambiguous cases of parasitosis in publications. The article describes two cases of suspected intestinal microsporidiosis. The difficulties and the probability of error of the microscopic method in the identification of intracellular protozoa on histosections are discussed.

Clinical, serological and therapeutic profile of ocular toxoplasmosis diagnosed at Batna University Hospital, Algeria

Objectives. Toxoplasmosis is a widespread parasitic infection worldwide, caused by an obligate intracellular protozoan called Toxoplasma gondii. Ocular toxoplasmosis is a common condition, being the main cause of infection affecting the posterior part of the eye. In Algeria, the actual prevalence of this infection remains poorly documented. It is in this context, we undertook this study with the aim of evaluating the seroprevalence of ocular toxoplasmosis diagnosed at Batna University Hospital and identifying the clinical and therapeutic characteristics. Materials and Methods. This prospective, descriptive, crosssectional study is conducted in the parasitology laboratory of Batna University Hospital, over a period of 27 months, from April 2020 to June 2023, sera of patients suspected of ocular toxoplasmosis as well as their retinal angiographies were received and analyzed. Diagnosis was established by measuring IgG and IgM by ELISA in the blood, compared with radiological, clinical and therapeutic data. Results. Among the 37 patients suspected of toxoplasmic chorioretinitis, 21 were serologically positive and no aqueous humor sample could be taken. The seroprevalence of probable ocular toxoplasmosis in our sample is thus 56.75%, there was a diversity of ages, ranging from 10 days to 65 years, the distribution by age shows that the two age groups that predominate in this study are those from 30 to 40 years, the levels of antitoxoplasmic IgG vary from 25 IU to 715 IU, in our series, the main reason for consultation was a decrease in visual acuity and the involvement was unilateral in the majority of cases, we collected isolated fresh foci 3 times, while the others presented a combination of fresh and scar foci, all patients in our sample followed an identical treatment regimen, combining two antibiotics (Sulfamethoxazole / Trimethoprim) and a bolus of corticosteroids. Conclusion: Ocular toxoplasmosis, whether acquired or congenital, remains one of the most significant clinical manifestations during infection with the T. gondii parasite

Adaptive and innate immune response of Leishmania infantum infection in Cirneco dell’Etna dog breed

Leishmania spp. are an intracellular protozoa present in many countries around the world. In Europe, both the parasite and the disease it causes, leishmaniasis, are endemic in the Mediterranean basin. Clinical signs and severity of disease are highly variable depending on the host in both humans and dogs, traditionally considered the main reservoir of the parasite. The reason for these differences is not known, but it has been speculated that some hosts present immune response, related to activation of Th1 and Th17, capable of controlling the spread of the parasite, and that these immune responses are related to the genetic background of the host. The Ibizan hound, an autochthonous canine breed of the Mediterranean basin, has been postulated as a breed resistant to infection, but other canine breeds evolutionarily close to it and native to this region have not been studied. One of them is the Cirneco dell’Etna, native to the island of Sicily in southern Italy. In this study, the immune response against L. infantum infection in this canine breed was analysed. The results showed that infected dogs of this breed present high levels of several cytokines related to Th1 and Th17 immune response, and significant correlation between serum levels of cytokines related to disease resistance. Further studies are necessary in this canine breed to determine the mechanisms of immune response and genetic background related to L. infantum infection control.

Leishmania donovani Modulates Macrophage Lipidome During Infection

ABSTRACTObligate intracellular protozoan parasite, Leishmania donovani, causative agent of visceral leishmaniasis, led to impaired macrophage functions. It is well documented that many of these changes were induced by parasite‐mediated reduction in macrophage cholesterol content. Leishmania‐mediated alteration in the other lipids has not been explored in detail yet. Here, we found that the expression of key cholesterol biosynthetic genes and total cellular cholesterol were reduced during L. donovani infection. Further, we have also identified that this reduction in the cholesterol led to increased membrane fluidity and inhibition of antigen‐presenting potential of macrophages. In addition to this, we studied the relative changes in different lipids in THP‐1‐derived macrophages during L. donovani infection through liquid chromatography‐mass spectrometry. We found that Sphingomyelin (16:0) and ceramide (20:1, 26:0 and 26:1) were significantly reduced in infected macrophages. We further observed that the majority of different sub‐classes of phospholipids were downregulated significantly. Overall ratio of phosphatidylcholine versus phosphotidylethanolamine was decreased which indicated the compensatory mechanism of cell in response to cholesterol reduction. The observed Leishmania‐mediated alteration in macrophage‐lipidome provided the novel insights into mechanism of host‐pathogen interactions.