RESUMO
The study conducted a review of the parasitological profile of vegetables from 2001 to 2021, considering the type, consumption, and cultivation, globally. The databases searched included MEDLINE, SciELO, Web of Science, Science Direct, and Scopus using the terms "Detection OR Prevalence OR Incidence OR occurrence OR contamination AND vegetable OR fruit AND Helminth OR egg OR Parasite OR cysts OR protozoa". A total of 16,600 articles were found, 117 of which were reviewed. Of the 391,291 samples, 3.85% (15,095) were contaminated by parasites. Among those positive, 30.10% (4,543/15,095) contained enteroparasites commonly of human origin and 58.78% (8,873/15,095) came from markets. Few articles mentioned the cultivation type, but among those, conventional cultivation showed more contamination (42.34%; 224/529). Herbaceous vegetables were the most contaminated (56.84%; 8,580/15,095. Ascaris lumbricoides was found in 10.16% (1,535/15,095) of the samples. Lettuce was the most contaminated (20.43%; 3,084/15,095).
Assuntos
Verduras , Verduras/parasitologia , Humanos , Animais , Parasitos/isolamento & purificação , Parasitos/classificação , Contaminação de Alimentos/análise , Parasitologia de AlimentosRESUMO
To evaluate the alarm notification of artificial intelligence in detecting parasites on the KU-F40 Fully Automatic Feces Analyzer and provide a reference for clinical diagnosis in parasite diseases. A total of 1030 fecal specimens from patients in our hospital from May to June 2023 were collected, and parasite detection studies were conducted using the KU-F40 automated feces analyzer (normal mode method, floating-sedimentation mode method), acid-ether sedimentation method, and direct smear microscopy method, respectively. The positive detection rate of parasites in the 1030 fecal specimens was 22.9% (236 cases), of which the KU-F40 normal mode method had a detection rate of 16.3% (168 cases), the acid-ether sedimentation method had a detection rate of 19.0% (196 cases), and the direct smear microscopy method had a detection rate of 13.1% (135 cases). The detection rates of the first 2 methods were higher than those of the direct smear microscopy method, and the difference was statistically significant (Pâ <â .05). The detection rate of the KU-F40 floating-sedimentation mode method was 11.9% (123 cases), which was lower than that of the direct smear microscopy, and the difference was not statistically significant (P > .05). The sensitivity of the KU-F40 normal mode method, acid-ether sedimentation method, direct smear microscopy method, and the KU-F40 floating-sedimentation mode method were 71.2%, 83.1%, 57.2%, and 52.1%, respectively, and the specificity was 94.7%, 100%, 100%, and 97.7%, respectively. The coincidence rates of the KU-F40 normal mode method was 90.78%, with Kappa values of 0.633. The positive detection rate of parasites using the KU-F40 normal mode method is higher than that using the direct smear microscopy method. It has high sensitivity and specificity and has advantages such as high automation and fast detection speed. It can replace the microscopy method for routine screening and has higher clinical application value in the diagnosis of intestinal parasitic diseases.
Assuntos
Inteligência Artificial , Fezes , Humanos , Fezes/parasitologia , Sensibilidade e Especificidade , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Microscopia/métodos , Criança , Adolescente , Pré-Escolar , Idoso , Adulto Jovem , Parasitos/isolamento & purificação , Doenças Parasitárias/diagnósticoRESUMO
Pairwise host-parasite relationships are typically embedded in broader networks of ecological interactions, which have the potential to shape parasite evolutionary trajectories. Understanding this 'community context' of pathogen evolution is vital for wildlife, agricultural and human systems alike, as pathogens typically infect more than one host-and these hosts may have independent ecological relationships. Here, we introduce an eco-evolutionary model examining ecological feedback across a range of host-host interactions. Specifically, we analyse a model of the evolution of virulence of a parasite infecting two hosts exhibiting competitive, mutualistic or exploitative relationships. We first find that parasite specialism is necessary for inter-host interactions to impact parasite evolution. Furthermore, we find generally that increasing competition between hosts leads to higher shared parasite virulence while increasing mutualism leads to lower virulence. In exploitative host-host interactions, the particular form of parasite specialization is critical-for instance, specialization in terms of onward transmission, host tolerance or intra-host pathogen growth rate lead to distinct evolutionary outcomes under the same host-host interactions. Our work provides testable hypotheses for multi-host disease systems, predicts how changing interaction networks may impact virulence evolution and broadly demonstrates the importance of looking beyond pairwise relationships to understand evolution in realistic community contexts.
Assuntos
Evolução Biológica , Interações Hospedeiro-Parasita , Virulência , Animais , Simbiose , Parasitos/patogenicidade , Modelos BiológicosRESUMO
Consumption of raw and semi-raw aquatic products is strongly associated with the development of fish-borne parasitic diseases. Detection of fish-borne parasites in aquatic products is of great significance for the prevention and control of fish-borne parasitic diseases. This review describes the advances in the application of etiological, molecular biological and immunological techniques alone and in combinations for detection of fish-borne parasites, so as to provide insights into detection of fish-borne parasites.
Assuntos
Peixes , Parasitos , Animais , Peixes/parasitologia , Parasitos/isolamento & purificação , Parasitos/fisiologia , Parasitologia de Alimentos , Humanos , Doenças dos Peixes/parasitologia , Doenças dos Peixes/prevenção & controle , Doenças Parasitárias/parasitologia , Doenças Parasitárias/prevenção & controleRESUMO
Immunotherapy has emerged as a highly effective treatment for various tumors. However, the variable response rates associated with current immunotherapies often restrict their beneficial impact on a subset of patients. Therefore, more effective treatment approaches that can broaden the scope of therapeutic benefits to a larger patient population are urgently needed. Studies have shown that some parasites and their products, for example, Plasmodium, Toxoplasma, Trypanosoma, and Echinococcus, can effectively transform "cold" tumors into "hot" battlefields and reshape the tumor microenvironment, thereby stimulating innate and adaptive antitumor immune responses. These parasitic infections not only achieve the functional reversal of innate immune cells, such as neutrophils, macrophages, myeloid-derived suppressor cells, regulatory T cells, and dendritic cells, in tumors but also successfully activate CD4+/CD8+ T cells and even B cells to produce antibodies, ultimately resulting in an antitumor-specific immune response and antibody-dependent cellular cytotoxicity. Animal studies have confirmed these findings. This review discusses the abovementioned content and the challenges faced in the future clinical application of antitumor treatment strategies based on parasitic infections. With the potential of these parasites and their byproducts to function as anticancer agents, we anticipate that further investigations in this field could yield significant advancements in cancer treatment.
Assuntos
Imunoterapia , Neoplasias , Humanos , Imunoterapia/métodos , Neoplasias/imunologia , Neoplasias/terapia , Animais , Parasitos/imunologia , Microambiente Tumoral/imunologiaRESUMO
The practice of hybridization is carried out globally in fish farms. Here, we present the first record of the parasitic fauna of hybrids among genus Colossoma and Piaractus in natural environments. We identified a total of 48 hybrids, nine F1 hybrids (nuclear DNA from both species present in the cross) and 38 advanced hybrids (nuclear DNA from one species), both from crosses between Piaractus brachypomus and Piaractus mesopotamicus, and one F1 "tambacu" corresponding to cross between Colossoma macropomum and Piaractus mesopotamicus. This is the first record of Anacanthorus penilabiatus, Anacanthorus toledoensis, Mymarothecium viatorum, Mymarothecium ianwhittington, Haementeria sp., Dadaytrema oxycephala, Rondonia rondoni, and Echinorhynchus gomesi parasitizing hybrids collected in a natural environment. With this, we expand knowledge about the diversity of fish and parasites in the upper Paraná River and warn about the risk that fish escapes can cause in the basin.
Assuntos
Hibridização Genética , Animais , Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Parasitos/classificação , Parasitos/genética , Parasitos/isolamento & purificação , Rios , Brasil , Doenças Parasitárias em Animais/parasitologiaRESUMO
This study examined the metrics of the macroparasite community in fishes from the Jaguaribe River basin, state of Ceará, before and after receiving water from the São Francisco River in Northeastern Brazil. This research assessed the association of environmental factors (water parameters) and the traits of 30 fish species on the parasite richness and abundance across space (river course) and time (seasons, pre- and post-transposition periods). Generalized linear models reveal associations between parasite metrics and host traits, water parameters, and river sub-basin. Host size and body condition positively correlated with parasite richness and abundance, while reproductive phase was negatively related. Water quality impacted ecto- and endoparasites differently, with seasonal and sub-basins variations and differences among sub-basins. The general models also indicate that the period is a significant variable, where parasite richness decreases while abundance increases in the post-transposition period. This study underscores the importance of considering diverse environmental and host variables for understanding parasite dynamics in river ecosystems. These findings could lead to valuable insights for ecosystem management and conservation, elucidating the potential consequences of environmental alterations on parasite-host interactions and ecosystem health.
Assuntos
Biodiversidade , Doenças dos Peixes , Peixes , Parasitos , Rios , Animais , Brasil , Rios/parasitologia , Peixes/parasitologia , Parasitos/classificação , Parasitos/isolamento & purificação , Doenças dos Peixes/parasitologia , Estações do Ano , Ecossistema , Doenças Parasitárias em Animais/parasitologia , Doenças Parasitárias em Animais/epidemiologiaRESUMO
Fish parasitology is a dynamic and internationally important discipline with numerous biological, ecological and practical applications. We reviewed optimal fish and parasite sampling methods for key ectoparasite phyla (i.e. Ciliophora, Platyhelminthes, Annelida and Arthropoda) as well as recent advances in molecular detection of ectoparasites in aquatic environments. Ideally, fish capture and anaesthesia as well as parasite recovery methods should be validated to eliminate potential sampling bias and inaccuracy in determining ectoparasite population parameters. There are considerable advantages to working with fresh samples and live parasites, when combined with appropriate fixation methods, as sampling using dead or decaying materials can lead to rapid decomposition of soft-bodied parasites and subsequent challenges for identification. Sampling methods differ between target phyla, and sometimes genera, with optimum techniques largely associated with identification of parasite microhabitat and the method of attachment. International advances in fish parasitology can be achieved through the accession of whole specimens and/or molecular voucher specimens (i.e. hologenophores) in curated collections for further study. This approach is now critical for data quality because of the increased application of environmental DNA (eDNA) for the detection and surveillance of parasites in aquatic environments where the whole organism may be unavailable. Optimal fish parasite sampling methods are emphasised to aid repeatability and reliability of parasitological studies that require accurate biodiversity and impact assessments, as well as precise surveillance and diagnostics.
Assuntos
Ectoparasitoses , Doenças dos Peixes , Peixes , Animais , Peixes/parasitologia , Ectoparasitoses/parasitologia , Ectoparasitoses/veterinária , Ectoparasitoses/diagnóstico , Doenças dos Peixes/parasitologia , Doenças dos Peixes/diagnóstico , Manejo de Espécimes/métodos , Parasitos/isolamento & purificação , Parasitologia/métodosRESUMO
This article presents a checklist of metazoan parasites of snakes from Argentina, along with a comprehensive review of the relevant literature published between 1922 and June 2023, covering various aspects of interest. We compiled 34 species of metazoan endoparasites from 28 studies. The subclass Digenea showed the highest number of species (n = 22 species), followed by the phylum Nematoda (n = 8 species), and the subclass Pentastomida (n = 3 species and 1 taxa inquirenda). Dipsadidae was the family of snakes with the most species examined for metazoan endoparasites (n = 20 species). In contrast, Viperidae had the largest number of specimens surveyed (n = 343). Of 23 provinces, 15 (65.2%) presented at least one report of metazoan endoparasites in snakes. The northeastern provinces showed the highest richness of metazoan endoparasites and host diversity. Many articles focused on taxonomy, but studies on parasite ecology were not found. Although taxonomic accuracy was high in most reports, some records were correctly deposited in zoological collections or geo-referenced. This is the first attempt to include all groups of metazoan endoparasites of snakes from Argentina in a single checklist in the last century.
Assuntos
Serpentes , Animais , Serpentes/parasitologia , Argentina , Lista de Checagem , Parasitos/classificação , Parasitos/isolamento & purificação , Nematoides/classificação , Nematoides/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Doenças Parasitárias em Animais/epidemiologia , BiodiversidadeRESUMO
The development of rapid, accurate, and efficient detection methods for protozoan parasites can substantially control the outbreak of protozoan parasites infection, which poses a threat to global public health. Idealistically, electrochemical biosensors would be able to overcome the limitations of current detection methods due to their simplified detection procedure, on-site quantitative analysis, rapid detection time, high sensitivity, and portability. The objective of this scoping review is to evaluate the current state of electrochemical biosensors for detecting protozoan parasites. This review followed the most recent Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) recommendations. Using electrochemical biosensor and protozoan parasite keywords, a literature search was conducted in PubMed, Scopus, Web of Science, and ScienceDirect on journals published between January 2014 and January 2022. Of the 52 studies, 19 were evaluated for eligibility, and 11 met the review's inclusion criteria to evaluate the effectiveness and limitations of the developed electrochemical biosensor platforms for detecting protozoan parasite including information about the samples, biomarkers, bioreceptors, detection system platform, nanomaterials used in fabrication, and limit of detection (LoD). Most electrochemical biosensors were fabricated using conventional electrodes rather than screen-printed electrodes (SPE). The range of the linear calibration curves for the developed electrochemical biosensors was between 200 ng/ml and 0.77 pM. The encouraging detection performance of the electrochemical biosensors demonstrate their potential as a superior alternative to existing detection techniques. On the other hand, more study is needed to determine the sensitivity and specificity of the electrochemical sensing platform for protozoan parasite detection.
Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/métodos , Humanos , Infecções por Protozoários/diagnóstico , Infecções por Protozoários/parasitologia , Parasitos/isolamento & purificação , AnimaisRESUMO
In this paper we study invasion probabilities and invasion times of cooperative parasites spreading in spatially structured host populations. The spatial structure of the host population is given by a random geometric graph on [0,1]n, n∈N, with a Poisson(N)-distributed number of vertices and in which vertices are connected over an edge when they have a distance of at most rN with rN of order N(ß-1)/n for some 0<ß<1. At a host infection many parasites are generated and parasites move along edges to neighbouring hosts. We assume that parasites have to cooperate to infect hosts, in the sense that at least two parasites need to attack a host simultaneously. We find lower and upper bounds on the invasion probability of the parasites in terms of survival probabilities of branching processes with cooperation. Furthermore, we characterize the asymptotic invasion time. An important ingredient of the proofs is a comparison with infection dynamics of cooperative parasites in host populations structured according to a complete graph, i.e. in well-mixed host populations. For these infection processes we can show that invasion probabilities are asymptotically equal to survival probabilities of branching processes with cooperation. Furthermore, we build on proof techniques developed in Brouard and Pokalyuk (2022), where an analogous invasion process has been studied for host populations structured according to a configuration model. We substantiate our results with simulations.
Assuntos
Interações Hospedeiro-Parasita , Animais , Parasitos , Probabilidade , Humanos , Dinâmica PopulacionalRESUMO
Parasites are commonly associated with harm, but they also have beneficial aspects that are still being discovered. It is important to acknowledge both the harmful and beneficial aspects of parasites. They have been found to have positive effects on non-healing wounds, surgical wounds, obesity, glucose metabolism disorders, nerve repair, cancer treatments, and fertility. Research has shown that helminths, protozoa, and arthropods have the ability to correct, prevent, and cure certain disorders through the use of the parasite itself, its molecules, or even its eggs. This article includes studies on the beneficial aspects of parasites. However, further research is needed to fully understand the mechanisms by which parasites stimulate or affect the immune system and how they can be used therapeutically.
Assuntos
Parasitos , Animais , Humanos , Parasitos/classificação , Artrópodes , Helmintos/classificação , Doenças Parasitárias/parasitologiaRESUMO
The construction of dams and hydroelectric plants affects biodiversity in aquatic environments and can facilitate the invasion of species. Few studies assess the long-term response of parasite fauna under these events. The aim of this study was to investigate possible changes in the endoparasite composition of the invasive catfish Trachelyopterus galeatus (Linnaeus, 1766) in the floodplain of the upper Paraná River over a 27-year study period. A total of 79 fish were collected in period 1 (1993) and 31 in period 2 (2019/2020) at the same sampling points, and the endoparasites were located in the gastrointestinal system using a stereomicroscope. It was found that the development of the fish and the composition of their endoparasitic fauna changed over time. In the second period, the fish presented smaller values for mass (g) and standard length (cm) when compared to period 1. It was found that three species of endoparasites were found per period, but although the richness was the same, the composition differed, and only one digenean (Microrchis oligovitellum Lunaschi, 1987 (Trematoda: Paramphistomidae)) was shared. The Porto Primavera Dam was built upstream of the site between the sampling periods (1999) and caused a number of environmental changes, possibly being the main factor responsible for changes in components of the parasite community. Anthropic modification to an environment can cause loss of diversity and loss of ecological interactions. Through our results, we emphasize the importance of including parasite fauna in studies that assess environmental impacts.
Assuntos
Peixes-Gato , Doenças dos Peixes , Espécies Introduzidas , Rios , Animais , Peixes-Gato/parasitologia , Doenças dos Peixes/parasitologia , Brasil , Rios/parasitologia , Biodiversidade , Parasitos/isolamento & purificação , Parasitos/classificação , Parasitos/fisiologiaRESUMO
Parasites are ubiquitous in wildlife populations and have a profound impact on population dynamics. Interest in parasites of wildlife has increased significantly in recent years, particularly in those with relevant conservation status. Patagonia is one of the wildest and remote areas of the world. The Wolffsohn's viscacha lives in a small mountainous area of Patagonia. Until now, little is known about the biology and ecology of this species. The aim of this research was to study the gastrointestinal parasite diversity in this rodent from a coprological survey. A total of 125 fecal samples from 25 colonies were examined. Each sample was rehydrated, homogenized, and analyzed using three parasitological techniques: spontaneous sedimentation, Mini-FLOTAC, and centrifugation-flotation in sucrose-saturated solution, followed by examination under optical microscopy. The samples, eggs, and oocysts of parasites were described, measured, and photographed. All colonies were positive for at least one parasite species. A total of 10 parasitic species were identified: Viscachataenia sp., possibly V. quadrata, Monoecocestus sp., an unidentified anoplocephalid, Heteroxynema sp., possibly H. (Cavioxyura) viscaciae, Helminthoxys sp., possibly H. effilatus, an unidentified strongylid-type egg, Trichuris sp., two morphologies of unidentified coccidians and Eimeria sp. This is the first exhaustive study of gastrointestinal parasites in L. wolffsohni and a large number of eggs and oocysts of parasites were found. Our results highlight the use of noninvasive techniques for the study of parasites of wildlife hosts; as in the case of this rodent with a remote habitat, which makes sampling difficult. The results of our study provide baseline information on gastrointestinal parasite infections in this species.
Assuntos
Fezes , Animais , Fezes/parasitologia , Argentina , Roedores/parasitologia , Enteropatias Parasitárias/veterinária , Enteropatias Parasitárias/parasitologia , Doenças dos Roedores/parasitologia , Doenças dos Roedores/epidemiologia , Parasitos/isolamento & purificação , Parasitos/classificação , Microscopia , Trato Gastrointestinal/parasitologiaRESUMO
Vegetable and fruit contamination is recognized as a significant parasite transmission route. This review presents the current state of vegetables ad fruits contamination with food-borne parasitic protozoa worldwide. We consider the methodologies and strategies for detecting parasitic stages developed in the last decade and the contamination data. Asia had the highest number of reports (94 studies), followed by Africa (74 studies). At the country level, with 41 studies, Iran had the most reports among other countries, followed by Nigeria (28 studies). According to the studies included in the current review, 41.22% of vegetables and fruits were contaminated with different species of protozoan parasites. Among different continents, Asia accounted for the highest contamination rate of protozoan parasites (57.12%). Giardia spp. (10%) had the highest contamination rate in vegetables and fruits, followed by Entamoeba coli (8%), E. histolytica/dispar (7%), and Cryptosporidium spp. (6%). This study provides essential data for health authorities to develop food safety programs. The presence of protozoan parasites in fruits and vegetables highlights the critical need for maintaining rigorous food safety measures across the entire production and distribution process, particularly in countries that are major producers and distributors of these food items.
Assuntos
Contaminação de Alimentos , Frutas , Verduras , Verduras/parasitologia , Frutas/parasitologia , Contaminação de Alimentos/análise , Humanos , Animais , Inocuidade dos Alimentos , Parasitologia de Alimentos , Cryptosporidium/isolamento & purificação , Cryptosporidium/genética , Parasitos/isolamento & purificação , Parasitos/classificação , Parasitos/genética , Giardia/isolamento & purificação , Giardia/genética , Entamoeba/isolamento & purificação , Entamoeba/genética , ÁsiaRESUMO
Despite recent advances in the management and therapeutic of cancer, the treatment of the disease is limited by its high cost and severe side effects. In this scenario, there is an unmet need to identify novel treatment alternatives for this dreaded disease. Recently there is growing evidence that parasites may cause anticancer effects because of a negative correlation between parasitic infections and tumour growth despite some parasites that are known to exhibit pro-carcinogenic effects. It has been observed that parasites exert an anticancer effect either by activating the host's immune response or by secreting certain molecules that exhibit anticancer potential. The activation of the immune response by these parasitic organisms results in the inhibition of some of the hallmarks of cancer such as tumour proliferation, angiogenesis, and metastasis. This review summarizes the current advances as well as the mechanisms underlying the possible implications of this diverse group of organisms as anticancer agents.
Assuntos
Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/uso terapêutico , Parasitos/efeitos dos fármacos , Doenças Parasitárias/tratamento farmacológicoAssuntos
Invertebrados , Parasitos , Animais , Invertebrados/classificação , Parasitos/classificaçãoRESUMO
Parasites are generally associated with lower income countries in tropical and subtropical areas. Still, they are also prevalent in low-income communities in the southern United States. Studies characterizing the epidemiology of parasites in the United States are limited, resulting in little comprehensive understanding of the problem. This study investigated the environmental contamination of parasites in the southern United States by determining each parasite's contamination rate and burden in five low-income communities. A total of 499 soil samples of approximately 50 g were collected from public parks and private residences in Alabama, Louisiana, Mississippi, South Carolina, and Texas. A technique using parasite floatation, filtration, and bead-beating was applied to dirt samples to concentrate and extract parasite DNA from samples and detected via multiparallel quantitative polymerase chain reaction (qPCR). qPCR detected total sample contamination of Blastocystis spp. (19.03%), Toxocara cati (6.01%), Toxocara canis (3.61%), Strongyloides stercoralis (2.00%), Trichuris trichiura (1.80%), Ancylostoma duodenale (1.42%), Giardia intestinalis (1.40%), Cryptosporidium spp. (1.01%), Entamoeba histolytica (0.20%), and Necator americanus (0.20%). The remaining samples had no parasitic contamination. Overall parasite contamination rates varied significantly between communities: western Mississippi (46.88%), southwestern Alabama (39.62%), northeastern Louisiana (27.93%), southwestern South Carolina (27.93%), and south Texas (6.93%) (P <0.0001). T. cati DNA burdens were more significant in communities with higher poverty rates, including northeastern Louisiana (50.57%) and western Mississippi (49.60%) compared with southwestern Alabama (30.05%) and southwestern South Carolina (25.01%) (P = 0.0011). This study demonstrates the environmental contamination of parasites and their relationship with high poverty rates in communities in the southern United States.
Assuntos
Solo , Solo/parasitologia , Animais , Mississippi/epidemiologia , Louisiana/epidemiologia , Alabama/epidemiologia , South Carolina/epidemiologia , Texas/epidemiologia , Pobreza , Humanos , Parasitos/isolamento & purificação , Parasitos/genética , Parasitos/classificação , Helmintos/isolamento & purificação , Helmintos/classificação , Helmintos/genéticaRESUMO
The role of malate dehydrogenase (MDH) in the metabolism of various medically significant protozoan parasites is reviewed. MDH is an NADH-dependent oxidoreductase that catalyzes interconversion between oxaloacetate and malate, provides metabolic intermediates for both catabolic and anabolic pathways, and can contribute to NAD+/NADH balance in multiple cellular compartments. MDH is present in nearly all organisms; isoforms of MDH from apicomplexans (Plasmodium falciparum, Toxoplasma gondii, Cryptosporidium spp.), trypanosomatids (Trypanosoma brucei, T. cruzi) and anaerobic protozoans (Trichomonas vaginalis, Giardia duodenalis) are presented here. Many parasitic species have complex life cycles and depend on the environment of their hosts for carbon sources and other nutrients. Metabolic plasticity is crucial to parasite transition between host environments; thus, the regulation of metabolic processes is an important area to explore for therapeutic intervention. Common themes in protozoan parasite metabolism include emphasis on glycolytic catabolism, substrate-level phosphorylation, non-traditional uses of common pathways like tricarboxylic acid cycle and adapted or reduced mitochondria-like organelles. We describe the roles of MDH isoforms in these pathways, discuss unusual structural or functional features of these isoforms relevant to activity or drug targeting, and review current studies exploring the therapeutic potential of MDH and related genes. These studies show that MDH activity has important roles in many metabolic pathways, and thus in the metabolic transitions of protozoan parasites needed for success as pathogens.