The Role of Spermidine and Its Key Metabolites in Important, Pathogenic Human Viruses and in Parasitic Infections Caused by Plasmodium falciparum and Trypanosoma brucei.

The triamine spermidine is a key metabolite of the polyamine pathway. It plays a crucial role in many infectious diseases caused by viral or parasitic infections. Spermidine and its metabolizing enzymes, i.e., spermidine/spermine-N1-acetyltransferase, spermine oxidase, acetyl polyamine oxidase, and deoxyhypusine synthase, fulfill common functions during infection in parasitic protozoa and viruses which are obligate, intracellular parasites. The competition for this important polyamine between the infected host cell and the pathogen determines the severity of infection in disabling human parasites and pathogenic viruses. Here, we review the impact of spermidine and its metabolites in disease development of the most important, pathogenic human viruses such as SARS-CoV-2, HIV, Ebola, and in the human parasites Plasmodium and Trypanosomes. Moreover, state-of-the-art translational approaches to manipulate spermidine metabolism in the host and the pathogen are discussed to accelerate drug development against these threatful, infectious human diseases.

Investigating intestinal parasitic infections with emphasis on molecular identification of Strongyloides stercoralis and Trichostrongylus colubriformis in north of Iran.

Currently, parasitic infections are one of the important health problems in the world, especially in developing countries. This study aims to investigate intestinal parasites with an emphasis on molecular identification through the analysis of mitochondrial COX1 and ITS2 gene sequences of Strongyloides stercoralis (S. stercoralis) and Trichostrongylus spp. in north of Iran. Five hundred forty stool samples were collected from medical diagnostic laboratories affiliated with Mazandaran University of Medical Sciences in Sari city, north of Iran. First, all the samples were examined using direct smear, formalin-ether sedimentation, and trichrome staining technique. Suspected samples of Strongyloides larvae were cultured in agar plate. Then, DNA was extracted from samples containing Trichostrongylus spp. eggs and Strongyloides larvae. To amplify DNA, PCR was performed and the samples with a sharp band in electrophoresis were sequenced by Sanger method. Overall, the prevalence of parasitic infections in the study population was 5.4%. The highest and the lowest level of infection was observed with Trichostrongylus spp. and S. stercoralis at 3% and 0.2%, respectively. No traces of live Strongyloides larvae were seen in the culture medium of the agar plate. The six isolates obtained from the amplification of the ITS2 gene of Trichostrongylus spp. were sequenced, all of which were Trichostrongylus colubriformis. The sequencing results of COX1 gene indicated S. stercoralis. In the present study, the prevalence of intestinal parasitic infections in north of Iran has relatively decreased that its main reason can be due to the coronavirus epidemic and compliance with health principles. However, the prevalence of Trichostrongylus parasite was relatively high that it requires special attention to apply appropriate control and treatment strategies in this field.

The mRNA Vaccine Technology Era and the Future Control of Parasitic Infections.

Despite intensive long-term efforts, with very few exceptions, the development of effective vaccines against parasitic infections has presented considerable challenges, given the complexity of parasite life cycles, the interplay between parasites and their hosts, and their capacity to escape the host immune system and to regulate host immune responses. For many parasitic diseases, conventional vaccine platforms have generally proven ill suited, considering the complex manufacturing processes involved and the costs they incur, the inability to posttranslationally modify cloned target antigens, and the absence of long-lasting protective immunity induced by these antigens. An effective antiparasite vaccine platform is required to assess the effectiveness of novel vaccine candidates at high throughput. By exploiting the approach that has recently been used successfully to produce highly protective COVID mRNA vaccines, we anticipate a new wave of research to advance the use of mRNA vaccines to prevent parasitic infections in the near future. This article considers the characteristics that are required to develop a potent antiparasite vaccine and provides a conceptual foundation to promote the development of parasite mRNA-based vaccines. We review the recent advances and challenges encountered in developing antiparasite vaccines and evaluate the potential of developing mRNA vaccines against parasites, including those causing diseases such as malaria and schistosomiasis, against which vaccines are currently suboptimal or not yet available.

Potential of the CRISPR-Cas system for improved parasite diagnosis: CRISPR-Cas mediated diagnosis in parasitic infections: CRISPR-Cas mediated diagnosis in parasitic infections.

CRISPR-Cas technology accelerates development of fast, accurate, and portable diagnostic tools, typified by recent applications in COVID-19 diagnosis. Parasitic helminths cause devastating diseases afflicting 1.5 billion people globally, representing a significant public health and economic burden, especially in developing countries. Currently available diagnostic tests for worm infection are neither sufficiently sensitive nor field-friendly for use in low-endemic or resource-poor settings, leading to underestimation of true prevalence rates. Mass drug administration programs are unsustainable long-term, and diagnostic tools - required to be rapid, specific, sensitive, cost-effective, and user-friendly without specialized equipment and expertise - are urgently needed for rapid mapping of helminthic diseases and monitoring control programs. We describe the key features of the CRISPR-Cas12/13 system and emphasise its potential for the development of effective tools for the diagnosis of parasitic and other neglected tropical diseases (NTDs), a key recommendation of the NTDs 2021-2030 roadmap released by the World Health Organization.

Specificity of SARS-CoV-2 Antibody Detection Assays against S and N Proteins among Pre-COVID-19 Sera from Patients with Protozoan and Helminth Parasitic Infections.

We aimed to assess the specificity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody detection assays among people with tissue-borne parasitic infections. We tested three SARS-CoV-2 antibody-detection assays (cPass SARS-CoV-2 neutralization antibody detection kit [cPass], Abbott SARS-CoV-2 IgG assay [Abbott Architect], and Standard Q COVID-19 IgM/IgG combo rapid diagnostic test [SD RDT IgM/SD RDT IgG]) among 559 pre-COVID-19 seropositive sera for several parasitic infections. The specificity of assays was 95 to 98% overall. However, lower specificity was observed among sera from patients with protozoan infections of the reticuloendothelial system, such as human African trypanosomiasis (Abbott Architect; 88% [95% CI, 75 to 95]) and visceral leishmaniasis (SD RDT IgG; 80% [95% CI, 30 to 99]), and from patients with recent malaria in areas of Senegal where malaria is holoendemic (ranging from 91% for Abbott Architect and SD RDT IgM to 98 to 99% for cPass and SD RDT IgG). For specimens from patients with evidence of past or present helminth infection overall, test specificity estimates were all ≥96%. Sera collected from patients clinically suspected of parasitic infections that tested negative for these infections yielded a specificity of 98 to 100%. The majority (>85%) of false-positive results were positive by only one assay. The specificity of SARS-CoV-2 serological assays among sera from patients with tissue-borne parasitic infections was below the threshold required for decisions about individual patient care. Specificity is markedly increased by the use of confirmatory testing with a second assay. Finally, the SD RDT IgG proved similarly specific to laboratory-based assays and provides an option in low-resource settings when detection of anti-SARS-CoV-2 IgG is indicated.

Considering opportunistic parasitic infections in COVID-19 policies and recommendations.

The COVID-19 pandemic has led to a significant increase in the immunosuppressed population worldwide due to the disease pathology and extensive use of corticosteroids. This has subsequently increased the risk of opportunistic parasitic infections such as Toxoplasma gondii, Strongyloides stercoralis and other parasites in these patients. The reactivation of such parasites may remain unnoticed due to overlapping symptoms, the difficulty of diagnosis and lack of guidelines for opportunistic parasitic infections in COVID-19 management. Therefore, recommendations for systematic screening of high-risk patients in endemic regions and active research and surveillance to estimate the impact of these infections are required in COVID-19 policy guidelines.