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Current Opinion in Neurology Jun 2021Malaria, Chagas Disease and Human African Trypanosomiasis are vector-borne protozoan illnesses, frequently associated with neurological manifestations. Intriguing but... (Review)
Review
PURPOSE OF REVIEW
Malaria, Chagas Disease and Human African Trypanosomiasis are vector-borne protozoan illnesses, frequently associated with neurological manifestations. Intriguing but ignored, limited mainly to resource-limited, tropical settings, these disorders are now coming to light because of globalisation and improved diagnosis and treatment. Enhanced understanding of these illnesses has prompted this review.
RECENT FINDINGS
Methods of diagnosis have currently transitioned from blood smear examinations to immunological assays and molecular methods. Tools to assess neurological involvement, such as magnetic resonance imaging, are now increasingly available in regions and countries with high infection loads. Sleep and other electrophysiological technologies (electroencephalography, actigraphy) are also promising diagnostic tools but requiring field-validation. Access to treatments was formerly limited, even as limitations of agents used in the treatment are increasingly recognised. Newer agents are now being developed and trialled, encouraged by improved understanding of the disorders' molecular underpinnings.
SUMMARY
Prompt diagnosis and treatment are crucial in ensuring cure from the infections. Attention should also be due to the development of globally applicable treatment guidelines, the burden of neurological sequelae and elimination of the zoonoses from currently endemic regions.
Topics: Animals; Chagas Disease; Humans; Malaria, Cerebral; Trypanosomiasis, African
PubMed: 33709976
DOI: 10.1097/WCO.0000000000000919 -
Ticks and Tick-borne Diseases May 2018The use of molecular diagnostic techniques in the study of ticks and tick-borne agents has increased dramatically in the last few decades, and while conferring the... (Review)
Review
The use of molecular diagnostic techniques in the study of ticks and tick-borne agents has increased dramatically in the last few decades, and while conferring the advantages of rapidity, sensitivity and accuracy, they can also be misused by the research community, who have shown an increasing overreliance on the data they produce, often completely abandoning more traditional approaches such as microscopy and serology. In this short review examples are provided of 'findings' that are apparently at odds with well-established eco-epidemiological knowledge, ranging from descriptions of new species of pathogens to their detection in new hosts and ticks, often immediately incriminated as new reservoir hosts and vector ticks, respectively. Most examples have been taken from the Piroplasmorida or "piroplasm" species as they are often called. Researchers are urged to utilize molecular methods with as much awareness as possible of the system or systems they are investigating, and journal editors and their teams of reviewers should be encouraged to adopt a more critical approach to papers that contain data based solely on molecular methods without due regard to the underlying biology. Explanations for such findings should be offered and discussed.
Topics: Animals; Cattle; Humans; Microscopy; Molecular Diagnostic Techniques; Piroplasmida; Protozoan Infections; Protozoan Infections, Animal; Research; Research Design; Sensitivity and Specificity; Serologic Tests; Tick Infestations; Tick-Borne Diseases; Ticks
PubMed: 29567148
DOI: 10.1016/j.ttbdis.2018.03.005 -
Eastern Mediterranean Health Journal =... Dec 2020Cryptosporidium is a waterborne intestinal parasite that causes diarrhoea in low and middle-income countries worldwide. Reports from Mediterranean countries have... (Review)
Review
BACKGROUND
Cryptosporidium is a waterborne intestinal parasite that causes diarrhoea in low and middle-income countries worldwide. Reports from Mediterranean countries have documented the prevalence of cryptosporidiosis in children at various ages, also among cancer patients, and in cases of chronic kidney disease, haemodialysis, and organ transplant. Untill now, modified-acid staining preceded by stool concentration preparation remains the leading screening diagnostic test for the infection. In Jordan, few studies for cryptosporidiosis have been performed during the last 3 decades.
AIMS
This paper reviewed the status of cryptosporidiosis in Jordan and tracked recent updates for this emerging protozoal infection among different population groups.
METHODS
In this study, an online search was conducted on Google Scholar and PubMed databases using the keywords: Jordan, cryptosporidiosis and Cryptosporidium to inspect studies done on this parasite in Jordan.
RESULTS
Only 9 articles were identified from 1994 to 2019. These were analysed in terms of population group, demography, clinical history and the diagnostic tools used.
CONCLUSION
Cryptosporidiosis is still neglected in Jordan as indicated by the low number of studies over the last 3 decades and the prevalence is diverse depending on the diagnostic test used and socioeconomic status.
Topics: Child; Cryptosporidiosis; Cryptosporidium; Diarrhea; Feces; Humans; Jordan; Prevalence
PubMed: 33355397
DOI: 10.26719/emhj.20.065 -
Fundamental & Clinical Pharmacology Feb 2017CYP51 is an enzyme of sterol biosynthesis pathway present in animals, plants, protozoa and fungi. This enzyme is described as an important drug target that is still of... (Review)
Review
CYP51 is an enzyme of sterol biosynthesis pathway present in animals, plants, protozoa and fungi. This enzyme is described as an important drug target that is still of interest. Therefore, in this work, we reviewed the structure and function of CYP51 and explored the molecular modeling approaches for the development of new antifungal and antiprotozoans that target this enzyme. Crystallographic structures of CYP51 of some organisms have already been described in the literature, which enable the construction of homology models of other organisms' enzymes and molecular docking studies of new ligands. The binding mode and interactions of some new series of azoles with antifungal or antiprotozoan activities has been studied and showed important residues of the active site. Molecular modeling is an important tool to be explored for the discovery and optimization of CYP51 inhibitors with better activities, pharmacokinetics, and toxicological profiles.
Topics: 14-alpha Demethylase Inhibitors; Animals; Antifungal Agents; Antiprotozoal Agents; Binding Sites; Drug Design; Humans; Molecular Docking Simulation; Mycoses; Protein Binding; Protein Structure, Secondary; Protozoan Infections; Sterol 14-Demethylase; Substrate Specificity
PubMed: 27487199
DOI: 10.1111/fcp.12230 -
International Journal of Gynaecology... Oct 2023Trichomonas vaginalis infection is the most prevalent non-viral sexually transmitted infection (STI) in women and has been suggested as a risk factor for developing... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Trichomonas vaginalis infection is the most prevalent non-viral sexually transmitted infection (STI) in women and has been suggested as a risk factor for developing cervical cancer.
OBJECTIVE
We aimed to investigate the associations between T. vaginalis infection and cervical carcinogenesis.
SEARCH STRATEGY
A comprehensive systematic search was conducted in five databases on 21 October 2021.
SELECTION CRITERIA
Studies assessing the relationship between T. vaginalis infection, HPV co-infections, cervical dysplasia, and cervical cancer were found eligible.
DATA COLLECTION AND ANALYSIS
Summary estimates for pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated with a random-effects model. Statistical heterogeneity was measured with I and Cochran's Q tests.
MAIN RESULTS
The 29 articles included 473 740 women, of whom 8518 were T. vaginalis-positive. Our results showed that T. vaginalis-infected women had 1.79 times higher odds of being diagnosed with HPV co-infection (95% CI 1.27-2.53; I 95%). We also found that T. vaginalis infection was associated with high-grade squamous intraepithelial lesion diagnosis (OR 2.34, 95% CI 1.10-4.95; I 75%) and cervical cancer (OR 5.23, 95% CI 3.03-9.04; I 3%).
CONCLUSIONS
Our results showed an association between T. vaginalis and cervical carcinogenesis in sexually active women.
Topics: Humans; Female; Trichomonas vaginalis; Uterine Cervical Neoplasms; Papillomavirus Infections; Trichomonas Infections; Cervix Uteri; Trichomonas Vaginitis
PubMed: 37010897
DOI: 10.1002/ijgo.14763 -
Annals of Parasitology 2017Parasitic diseases of the central nervous system are associated with high mortality and morbidity. Many human parasites, such as Toxoplasma gondii, Entamoeba...
Parasitic diseases of the central nervous system are associated with high mortality and morbidity. Many human parasites, such as Toxoplasma gondii, Entamoeba histolytica, Trypanosoma cruzi, Taenia solium, Echinococcus spp., Toxocara canis, T. cati, Angiostrongylus cantonensis, Trichinella spp., during invasion might involve the CNS. Some parasitic infections of the brain are lethal if left untreated (e.g., cerebral malaria – Plasmodium falciparum, primary amoebic meningoencephalitis (PAM) – Naegleria fowleri, baylisascariosis – Baylisascaris procyonis, African sleeping sickness – African trypanosomes). These diseases have diverse vectors or intermediate hosts, modes of transmission and endemic regions or geographic distributions. The neurological, cognitive, and mental health problems caused by above parasites are noted mostly in low-income countries; however, sporadic cases also occur in non-endemic areas because of an increase in international travel and immunosuppression caused by therapy or HIV infection. The presence of parasites in the CNS may cause a variety of nerve symptoms, depending on the location and extent of the injury; the most common subjective symptoms include headache, dizziness, and root pain while objective symptoms are epileptic seizures, increased intracranial pressure, sensory disturbances, meningeal syndrome, cerebellar ataxia, and core syndromes. Many early symptoms of CNS invasion are often nonspecific therefore a diagnosis can be difficult. This article presents the epidemiology, pathophysiology and clinical manifestations of selected parasitic neuroinfections.
Topics: Antiparasitic Agents; Central Nervous System Parasitic Infections; Helminthiasis; Humans; Protozoan Infections
PubMed: 29385325
DOI: 10.17420/ap6304.111 -
Innate Lymphoid Cells in Protection, Pathology, and Adaptive Immunity During Apicomplexan Infection.Frontiers in Immunology 2019Apicomplexans are a diverse and complex group of protozoan pathogens including spp., spp., spp., and spp. They infect a wide variety of hosts and are a major health... (Review)
Review
Apicomplexans are a diverse and complex group of protozoan pathogens including spp., spp., spp., and spp. They infect a wide variety of hosts and are a major health threat to humans and other animals. Innate immunity provides early control and also regulates the development of adaptive immune responses important for controlling these pathogens. Innate immune responses also contribute to immunopathology associated with these infections. Natural killer (NK) cells have been for a long time known to be potent first line effector cells in helping control protozoan infection. They provide control by producing IL-12 dependent IFNγ and killing infected cells and parasites via their cytotoxic response. Results from more recent studies indicate that NK cells could provide additional effector functions such as IL-10 and IL-17 and might have diverse roles in immunity to these pathogens. These early studies based their conclusions on the identification of NK cells to be CD3-, CD49b+, NK1.1+, and/or NKp46+ and the common accepted paradigm at that time that NK cells were one of the only lymphoid derived innate immune cells present. New discoveries have lead to major advances in understanding that NK cells are only one of several populations of innate immune cells of lymphoid origin. Common lymphoid progenitor derived innate immune cells are now known as innate lymphoid cells (ILC) and comprise three different groups, group 1, group 2, and group 3 ILC. They are a functionally heterogeneous and plastic cell population and are important effector cells in disease and tissue homeostasis. Very little is known about each of these different types of ILCs in parasitic infection. Therefore, we will review what is known about NK cells in innate immune responses during different protozoan infections. We will discuss what immune responses attributed to NK cells might be reconsidered as ILC1, 2, or 3 population responses. We will then discuss how different ILCs may impact immunopathology and adaptive immune responses to these parasites.
Topics: Adaptive Immunity; Animals; Apicomplexa; Biomarkers; Cell Plasticity; Cytokines; Host-Parasite Interactions; Humans; Immunity, Innate; Immunophenotyping; Inflammation Mediators; Lymphocyte Subsets; Plasmodium; Protozoan Infections
PubMed: 30873151
DOI: 10.3389/fimmu.2019.00196 -
International Journal For Parasitology Dec 2018Theoretical studies predict that parasitic infection may impact host longevity and ultimately modify the trade-off between reproduction and survival. Indeed, a host may...
Theoretical studies predict that parasitic infection may impact host longevity and ultimately modify the trade-off between reproduction and survival. Indeed, a host may adjust its energy allocation in current reproduction to balance the negative effects of parasitism on its survival prospects. However, very few empirical studies tested this prediction. Avian haemosporidian parasites provide an excellent opportunity to assess the influence of parasitic infection on both host survival and reproduction. They are represented by three main genera (Plasmodium, Haemoproteus and Leucocytozoon) and are highly prevalent in many bird populations. Here we provide the first known long-term field study (12 years) to explore the effects of haemosporidian parasite infection and co-infection on fitness in two populations of great tits (Parus major), using a multistate modeling framework. We found that while co-infection decreased survival probability, both infection and co-infection increased reproductive success. This study provides evidence that co-infections can be more virulent than single infections. It also provides support for the life-history theory which predicts that reproductive effort can be adjusted to balance one's fitness when survival prospects are challenged.
Topics: Animals; Animals, Wild; Bird Diseases; Coinfection; Haemosporida; Longevity; Passeriformes; Protozoan Infections, Animal; Reproduction
PubMed: 30391229
DOI: 10.1016/j.ijpara.2018.06.007 -
Expert Opinion on Therapeutic Targets 2015The carbonic anhydrases (CAs, EC 4.2.1.1), a group of ubiquitously expressed metalloenzymes, are involved in numerous physiological and pathological processes, as well... (Review)
Review
INTRODUCTION
The carbonic anhydrases (CAs, EC 4.2.1.1), a group of ubiquitously expressed metalloenzymes, are involved in numerous physiological and pathological processes, as well as in the growth and virulence of pathogens belonging to bacteria, fungi and protozoa.
AREAS COVERED
CAs belonging to at least four genetic families, the α-, β-, γ- and η-CAs, were discovered and characterized in many pathogens: i) Bacteria encode enzymes from one or more such families, which were investigated as potential drug targets. Inhibition of bacterial CAs by sulfonamides/phenol derivatives lead to inhibition of growth of the pathogen for Helicobacter pylori, Mycobacterium tuberculosis, Brucella suis; ii) Fungi encode for α- and β-CAs, and inhibitors of the sulfonamide, thiol or dithiocarbamate type inhibited the growth of some of them (Malassezia globosa, Candida albicans, Crytpococcus neoformans, etc) in vivo; and iii) Protozoa encode α-, β- or η-CAs. Sulfonamide, thiols and hydroxamates effectively killed such parasites (Trypanosoma cruzi, Leishmania donovani chagasi, Plasmodium falciparum) in vivo.
EXPERT OPINION
None of the microorganism CAs is validated as drug targets as yet, but the inhibitors designed against many such enzymes showed interesting in vitro/in vivo results. By interfering with the activity of CAs from microorganisms, both pH homeostasis as well as crucial biosynthetic reactions are impaired, which lead to significant antiinfective effects, not yet exploited for obtaining pharmacological agents. As resistance to the clinically used antiinfectives is a serious healthcare problem worldwide, inhibition of parasite CAs may constitute an alternative approach for obtaining such agents with novel mechanisms of action.
Topics: Animals; Anti-Bacterial Agents; Antifungal Agents; Antiprotozoal Agents; Bacterial Infections; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Drug Design; Humans; Molecular Targeted Therapy; Mycoses; Protozoan Infections
PubMed: 26235676
DOI: 10.1517/14728222.2015.1067685 -
PLoS Neglected Tropical Diseases Mar 2021Intestinal parasitic infections, caused by helminths and protozoa, are globally distributed and major causes of worldwide morbidity. The gut microbiota may modulate...
Intestinal parasitic infections, caused by helminths and protozoa, are globally distributed and major causes of worldwide morbidity. The gut microbiota may modulate parasite virulence and host response upon infection. The complex interplay between parasites and the gut microbiota is poorly understood, partly due to sampling difficulties in remote areas with high parasite burden. In a large study of children in Guinea-Bissau, we found high prevalence of intestinal parasites. By sequencing of the 16S rRNA genes of fecal samples stored on filter paper from a total of 1,204 children, we demonstrate that the bacterial microbiota is not significantly altered by helminth infections, whereas it is shaped by the presence of both pathogenic and nonpathogenic protozoa, including Entamoeba (E.) spp. and Giardia (G.) lamblia. Within-sample diversity remains largely unaffected, whereas overall community composition is significantly affected by infection with both nonpathogenic E. coli (R2 = 0.0131, P = 0.0001) and Endolimax nana (R2 = 0.00902, P = 0.0001), and by pathogenic E. histolytica (R2 = 0.0164, P = 0.0001) and G. lamblia (R2 = 0.00676, P = 0.0001). Infections with multiple parasite species induces more pronounced shifts in microbiota community than mild ones. A total of 31 bacterial genera across all four major bacterial phyla were differentially abundant in protozoan infection as compared to noninfected individuals, including increased abundance of Prevotella, Campylobacter and two Clostridium clades, and decreased abundance of Collinsella, Lactobacillus, Ruminococcus, Veillonella and one Clostridium clade. In the present study, we demonstrate that the fecal bacterial microbiota is shaped by intestinal parasitic infection, with most pronounced associations for protozoan species. Our results provide insights into the interplay between the microbiota and intestinal parasites, which are valuable to understand infection biology and design further studies aimed at optimizing treatment strategies.
Topics: Adolescent; Animals; Bacteria; Child; Child, Preschool; Coinfection; Entamoeba; Feces; Female; Gastrointestinal Microbiome; Giardia; Guinea-Bissau; Helminths; Humans; Intestinal Diseases, Parasitic; Male; Protozoan Infections; RNA, Ribosomal, 16S
PubMed: 33657123
DOI: 10.1371/journal.pntd.0009232