Toxoplasma gondii infection and ABO blood groups: a systematic review and meta-analysis

The current study aimed to determine the prevalence of Toxoplasma gondii in ABO blood groups and assess the relationship between the prevalence of T. gondii and blood groups. A literature search was carried out for epidemiological studies that were published through December 2022. A random effects model was used to determine the OR and the pooled prevalence with a 95% CI. The estimated pooled prevalences of T. gondii infection in the A, B, AB and O blood groups were 38% (95% CI 27 to 48%), 38% (95% CI 29 to 47%), 36% (95% CI 26 to 45%) and 36% (95% CI 27 to 45%), respectively. Also, the pooled ORs of the relationship between the prevalence of T. gondii infection and the A, B, AB and O blood groups were 1.08 (95% CI 0.97 to 1.19), 1.10 (95% CI 0.95 to 1.28), 1.08 (95% CI 0.92 to 1.27) and 0.89 (95% CI 0.80 to 1.00), respectively. This meta-analysis did not show any relationship between the prevalence of T. gondii infection and ABO blood groups.

Toxoplasma infection and Rhesus blood group system: A systematic review and meta-analysis

BACKGROUND

Toxoplasmosis is one of the most common infections in humans and animals, which is caused by an obligate intracellular opportunistic parasite known as Toxoplasma gondii (T. gondii). Some data have shown that both Rhesus (Rh)-positive and Rh-negative individuals differ in response to biological factors, including Toxoplasma infection. Therefore, this systematic review and meta-analysis was conducted to investigate the scientific evidence regarding the possible association between the Rh blood group and Toxoplasma infection and to determine the seroprevalence of T. gondii in the Rh blood group system.

METHODS

The research was conducted on PubMed, ScienceDirect, ProQuest, and Google Scholar databases until January 2023. Twenty-one cross-sectional studies were included with a total of 10910 people. The data were synthesized using a random effect model with 95% confidence intervals (CIs).

RESULTS

The overall prevalence of T. gondii was calculated at 32.34% (CI 95%: 28.23-36.45%) and 33.35% (CI 95%: 19.73-46.96%) in Rh-positive and Rh-negative blood groups. In addition, the pooled OR for the relationship between the Rh blood group and the seroprevalence of T. gondii was 0.96 (95% CI: 0.72-1.28).

CONCLUSIONS

This meta-analysis showed a high prevalence of Toxoplasma infection in both Rh-negative and positive blood groups. This systematic review and meta-analysis revealed that no significant association was found between toxoplasmosis and Rh factor. Because of the limited number of studies in this field, more research is recommended to determine the exact relationship between toxoplasmosis and the Rh factor.

Live attenuated Leishmania infantum centrin deleted mutant (LiCen-/-) as a novel vaccine candidate: A field study on safety, immunogenicity, and efficacy against canine leishmaniasis

This study was designed to evaluate the safety, immunogenicity, and efficacy of a single dose of L. infantum (LiCen^-/-) live attenuated candidate vaccine against canine leishmaniasis (CanL). Eighteen healthy domestic dogs with no anti-Leishmania antibodies and negative leishmanin skin test (LST) were randomly inoculated intravenously with either L. infantum (LiCen^-/-) vaccine candidate in 10 dogs or phosphate-buffered saline (PBS) in 8 dogs. The safety, immunogenicity, and efficacy rate of L. infantum (LiCen^-/-) vaccine candidate against CanL were evaluated by different criteria, including clinical manifestations, injection-site lesion, hematology and biochemistry values, anti-Leishmania antibodies using direct agglutination test (DAT), delayed-type hypersensitivity (DTH) using LST, and CD4⁺ and CD8⁺ T-cells subsets, as well as by measuring interferon (IFN-γ), interleukin (IL-23), IL-17, and IL-10 cytokines. Spleen aspiration and detection of Leishmania parasite using parasitological examinations (microscopy and culture) were performed in both vaccinated and control groups. Two months after intervention, each dog was challenged intraperitoneally (IP) with wide type (WT) L. infantum. Two-month follow-up post vaccination showed no clinical signs and serious side effects associated with the vaccination. A significant increase was found in the expression of IL-17, CD4⁺, and CD8⁺ gene transcripts in PBMCs, as well as increased levels of Th1 cytokines, and reduction of Th2 cytokine. The efficacy of the vaccine candidate was calculated to be 42.85%. While the time window for assessing the vaccine's effectiveness was too limited to draw any real conclusions but the preliminary results showed a moderate efficacy rate due to inoculation a single dose of L. infantum (LiCen^-/-) vaccine candidate. Further investigations with more sample sizes and multiple doses of the vaccine candidate using natural challenges in the endemic areas of CanL are recommended.

Prevalence, genetic diversity and antifungal susceptibility profiles of F. fujikuroi, F. solani, and Fusarium incarnatum-equiseti species complexes from onychomycosis in North of Iran

Onychomycosis, a nail fungal infection, is normally caused by dermatophytes. However, yeasts and non-dermatophyte molds (NDM) are among pathogens that cause nail disease. Regarding, this study aimed to describe the molecular epidemiology of Fusarium onychomycosis in the North of Iran. 257 nail samples collected from the patients clinically suspected of onychomycosis were subjected to direct microscopy, calcofluor white staining, and culture. Fusarium isolates were identified at a species level through determination of multi-locus sequences for internal transcribed spacer and translation elongation factor 1 alpha. Based on the findings, Fusarium species were isolated from onychomycosis patients (n=27). According to a previous partial genes analysis, the species in the resent study belonged to the members of F. fujikuroi species complex (n=14), Fusarium incarnatum-equiseti species complex (n=1) and F. solani species complex (n=12). In rhis study, F. proliferatum was the dominant Fusarium species collected from the samples. The correct identification of Fusarium species is essential regarding the increased prevalence of Fusarium onychomycosis and the inherent resistance of these agents to a wide spectrum of antifungals. The obtained results indicated variation in the epidemiology of Fusarium species isolated from onychomycosis. Moreover, the minimum inhibitory concentration (MIC) of luliconazole and lanoconazole was in the range of 0.001-1 μg/mL, with the geometric mean of MICs obtained at 0.0103 and 0.0343 μg/mL against Fusarium species, respectively. These findings can increase researchers' knowledge regarding diversity of species, distribution of onychomycosis, and the choice of a proper treatment.

High occurrence of Blastocystis sp. subtype 3 in individuals referred to medical laboratories in Kermanshah, Iran

Aim

The current study investigated the prevalence and genotypes of Blastocystis sp. in individuals who referred to medical laboratories in Kermanshah, Iran.

Background

Blastocystis sp. is a common intestinal protozoan found in humans and a wide range of animals, and it is involved in the development of gastrointestinal disorders.

Methods

A total of 950 stool samples were examined using the standard formalin-ether concentration technique. All specimens were cultured in Robinson xenic medium. Subsequently, DNA extraction and PCR amplification of subtype specific sequence-tagged site (STS) were conducted.

Results

Microscopic examination showed that 86 out of 950 samples (9.05%) were infected with Blastocystis sp. Subsequently, 33 of 86 positive samples were cultured and molecularly confirmed by conventional PCR, indicating six subtypes (ST1-ST6). Of note, ST3 (45.0%) was the predominant subtype, followed by ST1 (15.15%) and ST5 (12%).

Conclusion

Based on the current findings, ST3 was the most frequent subtype among all positive samples. Having a better understanding of Blastocystis sp. subtype distribution and risk factors would lead to improved preventive measures.

Evaluation of the Effects of Rumex obtusifolius Seed and Leaf Extracts Against Acanthamoeba: An in vitro Study

BACKGROUND

Acanthamoebiasis treatment is a major and challenging problem due to the presence of resistant cyst form. Many herbal extracts and their derivatives have been used against trophozoites and cysts of Acanthamoeba, but no effective therapeutic agent has yet been discovered. Therefore, the present study aimed to evaluate the effect of Rumex obtusifolius (R. obtusifolius) extracts against a clinical strain of Acanthamoeba genotype T4 in vitro.

METHODS

In this experimental study, after genotyping the clinical isolate, the hydroalcohlic extracts of R. obtusifolius seeds and leaves were prepared. Different concentrations (1.25, 2.5, 5 and 10 mg/ml) of extracts were tested in triplicate (24, 48 and 72h) on trophozoites and cysts of Acanthamoeba. The mortality of the parasite was assessed by trypan blue vital staining and flow cytometry analysis.

RESULTS

Results showed that the extract of R. obtusifolius leaves at the concentration of 10 mg/ml killed 100% of trophozoites and cysts after 72 h. However, the seed extract of R. obtusifolius had weak inhibitory effects on trophozoites and cysts of Acanthamoeba. In the presence of 10 mg/ml of hydroalcoholic seed extract of R.obtusifolius in culture medium after 72 h, 28.6% of trophozoites and 0% of cysts of Acanthamoeba were killed. After analysis by flow cytometry, seeds and leaves extract indicated apoptosis effect. Seed and leaf extracts caused 2.6% and 0.4% percent apoptosis.

CONCLUSION

These extracts are not promising candidates for further medicine development on acanthamoebiasis. Nonetheless, further research is necessary to clarify the effects of effective fractions of seed and leaf extracts of R. obtusifolius and their mechanisms of action.

Expression of the herpes simplex virus type 2 glycoprotein D in baculovirus expression system and evaluation of its immunogenicity in guinea pigs

BACKGROUND

Herpes simplex virus type 2 (HSV-2) is highly prevalent and major cause of genital herpes in humans. The life-long nature of infection and the increasing prevalence of genital herpes imply that vaccination is the best strategy for controlling the spread of infection and limiting HSV disease. HSV glycoprotein D (gD) is one of the most important viral immunogen which has an essential role in virus infectivity and induction of immune responses.

METHODS

HSV-2 DNA was extracted and used as template in polymerase chain reactions to amplify gD2 gene. The PCR product was confirmed by restriction enzyme analysis, cloned into a cloning vector and then sequenced. The Bac-to-Bac expression system was used to express HSV-2 gD in insect cells. The expressed protein was used as subunit vaccine to immunize guinea pigs after confirmation.

RESULTS

The expressed protein was confirmed with SDS-PAGE and Western-blot analysis. In Western-blot analysis, two major protein bands, with approximate molecular weights of 52-55 and 41-43 kDa corresponding to the glycosylated and non-glycosylated forms of gD2 protein, were observed, respectively. Immunization with the recombinant gD2 could elicit humoral responses in guinea pigs as measured by neutralization test and ELISA, and offered high protection against induced HSV-2 genital disease.

CONCLUSION

The baculovirus expression of heterologous genes permits proper folding, post-translational modification and oligomerization in manners that are often identical to those that occur in mammalian cells. Expression of proteins under the control of the strong polyhedrin promoter, allowing high level protein production, can be used as subunit vaccine.

The effect of betamethasone and IFN-gamma on replication of Toxoplasma gondii (RH strain) and nitric oxide production in Hela cell culture

Toxoplasmosis is a protozoal infection caused by Toxoplasma gondii. Toxoplasmosis produce severe damage in patients who are immunosuppressed. In those who are immunosuppressed, latent infection can be reactivated resulting in acute disseminating disease. Betamethasone is a synthetic glycocorticoid, used as an anti-inflammatory and immunosuppressant in a wide variety of disorders. The aim of this study was evaluation of betamethasone as an immunosuppressor drug on infected cells by Toxoplasma gondii. In this study, at first HeLa cells were grown in 24 well culture plates in culture medium . When confluent monolayer was obtained, we compared 6 groups to evaluate the effect of betamethasone as a corticosteroid drug (two concentrations 4 and 40 micro g/ml) and the effect of IFN-gamma (100 IU/ml ) on growth, replication and Nitric Oxide (NO) production. The results showed, that high number of plaques were seen in group with 40 mug/ml of betamethasone and the lowest number of plaques were seen in group with 100 IU of IFN-gamma. The difference between plaque number in control and groups treated with IFN-gamma and betamethasone was significant (P<0.05). The groups with betamethasone or IFN-gamma without tachyzoites did not show any effect on cell structures. Replication rates in the wells treated with IFN-gamma were decreased significantly 72 h post inoculation in comparison with control group (P<0.05). There was no significant difference among different groups in NO production. The results indicated that betamethasone increase the invasion of tachyzoites to host cells in vitro.