Vanadium compounds as antiparasitic agents: An approach to their mechanisms of action.

BACKGROUND: Parasitic infections are a public health problem since they have high morbidity and mortality worldwide. In parasitosis such as malaria, leishmaniasis and trypanosomiasis it is necessary to develop new compounds for their treatment since an increase in drug resistance and toxic effects have been observed. Therefore, the use of different compounds that couple vanadium in their structure and that have a broad spectrum against different parasites have been proposed experimentally. OBJECTIVE: Report the mechanisms of action exerted by vanadium in different parasites. CONCLUSION: In this review, some of the targets that vanadium compounds have were identified and it was observed that they have a broad spectrum against different parasites, which represents an advance to continue investigating therapeutic options.

Revisão integrativa sobre doenças parasitárias em crianças de creches brasileiras / Integrative review on parasitic diseases in children in brazilian day care centers

As parasitoses intestinais constituem um importante problema de Saúde Pública, especialmente entre os pré-escolares, devido à imaturidade do sistema imune. Assim, este estudo objetivou realizar uma revisão integrativa dos estudos publicados entre os anos de 2010 a 2017 sobre parasitoses intestinais e os fatores associados ao desenvolvimento em crianças matriculadas em creches brasileiras. Foi realizada busca bibliográfica através das bases de dados Medline, Lilacs e SciELO, utilizando os descritores: infecção, parasitoses, diarreia e creches, e seus correspondentes em inglês: "infection", "parasitc diseases", "diarrhea" e "child day care centers". No caso das buscas no Medline o descritor Brazil também foi usado. Foram identificados 59 estudos, dos quais 11 foram incluídos no presente trabalho. Foi observado variação de 19,4% a 98,4% de parasitos e, a Giardia duodenalis foi o mais prevalente em crianças entre um e seis anos de idade, gênero masculino, com baixo peso, advindas de residências com alta densidade familiar e nível socioeconômico baixo. As análises mostraram a importância da compreensão dos fatores de risco para a incidência de parasitos, indicando a necessidade da promoção de estratégias efetivas para prevenção e controle das infecções parasitárias no país, visto que, tais infecções influenciam diretamente no desenvolvimento da criança, e em alguns casos, evoluindo a óbito.

Intestinal parasitosis is an important public health issue especially among pre-school children due to the immaturity of their immune system. Thus, this study aimed at carrying out an integrative review of studies published between 2010 and 2017 regarding intestinal parasites and associated factors in children registered in Brazilian day care centers. A bibliographic survey was performed through the Medline, Lilacs, and SciELO databases using the following descriptors: infection, parasitic diseases, diarrhea, and child day care centers, as well as their corresponding translations in Portuguese: "infecção", "parasitoses", "diarreia" and "creches". In the case of Medline searches, the descriptor Brazil was also used. Fifty-nine studies were identified, from which, 11 were included in this study. A variation of 19.4% to 98.4% of parasites could be observed, with Giardia duodenalis being the most prevalent in children between one and six years old, male, with low weight, coming from homes with high family density and low socioeconomic status. The analyzes showed the importance of understanding the risk factors for the incidence of parasites, showing the need to promote effective strategies for the prevention and control of parasitic infections in the country, since such infections have direct influence on the child's development, and in some cases, even evolving to death.

How much epigenetics and quantitative trait loci (QTL) mapping tell us about parasitism maintenance and resistance/susceptibility to hosts.

Interactions between the environment, parasites, vectors, and/or intermediate hosts are complex and involve several factors that define the success or failure of an infection. Among these interactions that can affect infections by a parasite, it is possible to highlight the genetic and epigenetic mechanisms in hosts and parasites. The interaction between genetics, epigenetics, infection, and the host's internal and external environment is decisive and dictates the outcome of a parasitic infection and the resistance, susceptibility, and transmission of this parasite. Epigenetic changes become important mediators in the regulation of gene expression, allowing the evasion of the parasite to immune host barriers, its transmission to new hosts, and the end of its development cycle. Epigenetics is a new frontier in the understanding of the interaction mechanisms between parasite and host that, along with information from the gene regions associated with complex phenotypic variations, the Quantitative Trait Loci, brings new possibilities to investigate more modern and efficient approaches to the treatment, control, and eradication of parasitic diseases. In this brief review, a general overview of the use of epigenetic information and mapping of Quantitative Trait Loci was summarized, both in genes of parasites and hosts, for understanding the mechanisms of resistance and/or susceptibility in parasitic relationships; also, the main search platforms were quantitatively compared, aiming to facilitate access data produced over a period of twenty years.

Neurological Infection, Kynurenine Pathway, and Parasitic Infection by Neospora caninum.

Neuroinflammation is one of the most frequently studied topics of neurosciences as it is a common feature in almost all neurological disorders. Although the primary function of neuroinflammation is to protect the nervous system from an insult, the complex and sequential response of activated glial cells can lead to neurological damage. Depending on the type of insults and the time post-insult, the inflammatory response can be neuroprotective, neurotoxic, or, depending on the glial cell types, both. There are multiple pathways activated and many bioactive intermediates are released during neuroinflammation. One of the most common one is the kynurenine pathway, catabolizing tryptophan, which is involved in immune regulation, neuroprotection, and neurotoxicity. Different models have been used to study the kynurenine pathway metabolites to understand their involvements in the development and maintenance of the inflammatory processes triggered by infections. Among them, the parasitic infection Neospora caninum could be used as a relevant model to study the role of the kynurenine pathway in the neuroinflammatory response and the subset of cells involved.

Loop-Mediated Isothermal Amplification as Point-of-Care Diagnosis for Neglected Parasitic Infections.

The World Health Organisation (WHO) has placed twenty diseases into a group known as neglected tropical diseases (NTDs), twelve of them being parasitic diseases: Chagas' disease, cysticercosis/taeniasis, echinococcosis, food-borne trematodiasis, human African trypanosomiasis (sleeping sickness), leishmaniasis, lymphatic filariasis, onchocerciasis (river blindness), schistosomiasis, soil-transmitted helminthiasis (ascariasis, hookworm, trichuriasis), guinea-worm and scabies. Such diseases affect millions of people in developing countries where one of the main problems concerning the control of these diseases is diagnosis-based due to the most affected areas usually being far from laboratories having suitable infrastructure and/or being equipped with sophisticated equipment. Advances have been made during the last two decades regarding standardising and introducing techniques enabling diagnoses to be made in remote places, i.e., the loop-mediated isothermal amplification (LAMP) technique. This technique's advantages include being able to perform it using simple equipment, diagnosis made directly in the field, low cost of each test and the technique's high specificity. Using this technique could thus contribute toward neglected parasite infection (NPI) control and eradication programmes. This review describes the advances made to date regarding LAMP tests, as it has been found that even though several studies have been conducted concerning most NPI, information is scarce for others.

Alta prevalência de Balantidium coli em crianças de uma Escola Municipal de Moreira Sales - Pr / High prevalence of balantidium coli in children of a Municipal School in Moreira Sales - Pr

As doenças causadas por parasitos intestinais estão entre os mais frequentes agravos do mundo, pois é um problema de saúde pública que atinge a maioria da população. O presente estudo teve como objetivo verificar a prevalência de parasitos em crianças de 4 a 6 anos de uma escola municipal de Moreira Sales, PR. A pesquisa foi composta por inquérito parasitológico e epidemiológico em crianças matriculadas em uma escola municipal em julho de 2017. O critério para inclusão no estudo foi: coletar a amostra de fezes, responder o questionário socioepidemiológico e ter o Termo de Consentimento Livre e Esclarecido (TCLE) assinado pelos pais e/ou responsáveis. Participaram do estudo 42 crianças com idades entre 4 e 6 anos, das quais 66,7% eram meninas. Dos participantes, dez crianças (23,8%) apresentaram infecção por Balantidium coli, sendo que destas, duas apresentaram infecção mista por Entamoeba coli. Foi observado que a maioria dos infectados possuíam animais de estimação (60%), roíam unhas (60%), consumiam hortaliças (80%) e todas as crianças brincavam na terra, sendo esses alguns fatores de risco para a infecção. Diante dos resultados apresentados, é possível perceber que existem vários fatores que podem estar associados à infecção por Balantidium coli, sendo os principais: falta de saneamento básico e os hábitos de higiene inadequado. Portanto, fatores importantes para se promover a conscientização e ação profilática da população, com o intuito de minimizar as parasitoses, principalmente nas crianças.

Diseases caused by intestinal parasites are among the most frequent ones in the world, since it is a public health issue affecting most of the population. The purpose of this study was to verify the prevalence of parasites in children aged 4 to 6 years at a school in the municipality of Moreira Sales, in the state of Paraná, Brazil. The study was comprised by the parasitological and epidemiological investigation in children enrolled in a school in the city in July 2017. The criteria for inclusion in the study was to collect the stool sample, answer the socio-epidemiological questionnaire and sign a Free and Clarified Consent Form. A total of 42 children took part in this study, with ages ranging between 4 and 6 years, of which 66.7% were female. From the participants, ten children (23.8%) presented infection by Balantidium coli, and among which, two of them presented mixed infection by Entamoeba coli. It was observed that most of the infected children had pets (60%), bit their nails (60%), consumed vegetables (80%) and all children played on dirt, which are some of the risk factors for infection. Considering the results, it is possible to observe that there are several factors that can be associated to infection by Balantidium coli, among which: basic sanitation and hygiene habits. Therefore, raising awareness and presenting prophylactic action to the population is essential in order to minimize intestinal parasitosis, especially in children.

CCR5 and CCR5Δ32 in bacterial and parasitic infections: Thinking chemokine receptors outside the HIV box.

The CCR5 molecule was reported in 1996 as the main HIV-1 co-receptor. In that same year, the CCR5Δ32 genetic variant was described as a strong protective factor against HIV-1 infection. These findings led to extensive research regarding the CCR5, culminating in critical scientific advances, such as the development of CCR5 inhibitors for the treatment of HIV infection. Recently, the research landscape surrounding CCR5 has begun to change. Different research groups have realized that, since CCR5 has such important effects in the chemokine system, it could also affect other different physiological systems. Therefore, the effect of reduced CCR5 expression due to the presence of the CCR5Δ32 variant began to be further studied. Several studies have investigated the role of CCR5 and the impacts of CCR5Δ32 on autoimmune and inflammatory diseases, various types of cancer, and viral diseases. However, the role of CCR5 in diseases caused by bacteria and parasites is still poorly understood. Therefore, the aim of this article is to review the role of CCR5 and the effects of CCR5Δ32 on bacterial (brucellosis, osteomyelitis, pneumonia, tuberculosis and infection by Chlamydia trachomatis) and parasitic infections (toxoplasmosis, leishmaniasis, Chagas disease and schistosomiasis). Basic information about each of these infections was also addressed. The neglected role of CCR5 in fungal disease and emerging studies regarding the action of CCR5 on regulatory T cells are briefly covered in this review. Considering the "renaissance of CCR5 research," this article is useful for updating researchers who develop studies involving CCR5 and CCR5Δ32 in different infectious diseases.

Apoptotic mimicry as a strategy for the establishment of parasitic infections: parasite- and host-derived phosphatidylserine as key molecule.

The establishment of parasitic infection is dependent on the development of efficient strategies to evade the host defense mechanisms. Phosphatidylserine (PS) molecules are pivotal for apoptotic cell recognition and clearance by professional phagocytes. Moreover, PS receptors are able to trigger anti-inflammatory and immunosuppressive responses by phagocytes, either by coupled enzymes or through the induction of regulatory cytokine secretion. These PS-dependent events are exploited by parasites in a mechanism called apoptotic mimicry. Generally, apoptotic mimicry refers to the effects of PS recognition for the initiation and maintenance of pathogenic infections. However, in this context, PS molecules can be recognized on the surface of the infectious agent or in the surface of apoptotic host debris, leading to the respective denomination of classical and non-classical apoptotic mimicry. In this review, we discuss the role of PS in the pathogenesis of several human infections caused by protozoan parasites. Video Abstract.

Microbiological contaminations of laboratory mice and rats in conventional facilities in Argentina.

Routine microbiological monitoring of rodent colonies in animal facilities is essential to evaluate the health status of the animals used in research studies. In the present study, animals were examined for the presence of selected microbial infections. In order to determine the contamination rates of mice and rats in Argentina, animals from 102 conventional facilities were monitored from 2012 to 2016. The most frequent bacteria isolated were Pseudomonas aeruginosa and Proteus spp. The common parasites identified were Syphacia spp. and Tritrichomonas spp. Serological assays demonstrated the highest prevalence for Mouse hepatitis virus in mice and Sialodacryoadenitis virus in rats. The results indicate that there is a high incidence of infections, so it is suggested that an efficient management system and effective sanitary barriers should be implemented in conventional facilities in Argentina in order to improve sanitary standards.

Patterns of distribution, population genetics and ecological requirements of field-occurring resistant and susceptible Pseudosuccinea columella snails to Fasciola hepatica in Cuba.

Pseudosuccinea columella snails transmit the trematode Fasciola hepatica, but in Cuba, six naturally occurring populations successfully resist parasite infection. Here, we present an updated distribution of P. columella in Cuba; 68 positive sites with the earliest records more abundant in west-central Cuba and with east-central populations generally corresponding to the newest samples. No records were found farther east. The IPA site reported 10.5% prevalence of F. hepatica-infected snails. Population genetics, studied through microsatellites, showed low allelic and multilocus genotypic richness (MLGT), mainly in susceptible populations, strong deviations from panmixia and high self-fertilization rates. Susceptible individuals were grouped in one major cluster containing the majority of MLGT, and two independent clusters grouped the MLGT of resistant individuals from western and central populations, respectively. From these, we propose that several introductions of P. columella occurred in Cuba, primarily in the west, with the early arrivals deriving on the resistant populations. A more recent introduction of susceptible P. columella carrying MLGT T and Y may have occurred, where the latter spread quickly through the island and possibly increase the risk of parasite transmission in Cuba since all snails naturally infected with F. hepatica were carriers of the MLGT Y. Interestingly, even though resistant populations are highly diverse and are likely the oldest within Cuba, they are only found in six localities characterized by soft (total hardness, TH = 6.3 ± 1.03°d) and slightly acidic (pH = 6.2 ± 0.12) waters with low richness in snail species (3.2 ± 1.02). This tendency was also observed in a two-year follow-up ecological study that was conducted on a farm where both phenotypes occurred in sympatry; colonization events by resistant over susceptible snails coincided with a reduction in the pH and TH of the water. A comparison of life traits in susceptible and resistant isolates reared at two different pH/TH conditions (5.9/4°d or 7.8/14°d) showed that low pH/TH negatively affects P. columella, irrespective of the phenotype. However, evidence of higher tolerance (higher survival, life expectancy, egg viability) to such conditions was observed in resistant isolates. Finally, we speculate that the limited distribution of resistant populations might be related to a better exploitation of sites that are less suitable to snails (thus, with lower competition), rather than to a differential ecological restriction to specific environmental conditions from susceptible P. columella.

Phenolic Compounds from Humulus lupulus as Natural Antimicrobial Products: New Weapons in the Fight against Methicillin Resistant Staphylococcus aureus, Leishmania mexicana and Trypanosoma brucei Strains.

New anti-infective agents are urgently needed to fight microbial resistance. Methicillin-resistant Staphylococcus aureus (MRSA) strains are particularly responsible for complicated pathologies that are difficult to treat due to their virulence and the formation of persistent biofilms forming a complex protecting shell. Parasitic infections caused by Trypanosoma brucei and Leishmania mexicana are also of global concern, because of the mortality due to the low number of safe and effective treatments. Female inflorescences of hop produce specialized metabolites known for their antimicrobial effects but underexploited to fight against drug-resistant microorganisms. In this study, we assessed the antimicrobial potential of phenolic compounds against MRSA clinical isolates, T. brucei and L. mexicana. By fractionation process, we purified the major prenylated chalcones and acylphloroglucinols, which were quantified by UHPLC-UV in different plant parts, showing their higher content in the active flowers extract. Their potent antibacterial action (MIC < 1 µg/mL for the most active compound) was demonstrated against MRSA strains, through kill curves, post-antibiotic effects, anti-biofilm assays and synergy studies with antibiotics. An antiparasitic activity was also shown for some purified compounds, particularly on T. brucei (IC50 < 1 to 11 µg/mL). Their cytotoxic activity was assessed both on cancer and non-cancer human cell lines.

Analysis of Predicted Host-Parasite Interactomes Reveals Commonalities and Specificities Related to Parasitic Lifestyle and Tissues Tropism.

The study of molecular host-parasite interactions is essential to understand parasitic infection and adaptation within the host system. As well, prevention and treatment of infectious diseases require a clear understanding of the molecular crosstalk between parasites and their hosts. Yet, large-scale experimental identification of host-parasite molecular interactions remains challenging, and the use of computational predictions becomes then necessary. Here, we propose a computational integrative approach to predict host-parasite protein-protein interaction (PPI) networks resulting from the human infection by 15 different eukaryotic parasites. We used an orthology-based approach to transfer high-confidence intraspecies interactions obtained from the STRING database to the corresponding interspecies homolog protein pairs in the host-parasite system. Our approach uses either the parasites predicted secretome and membrane proteins, or only the secretome, depending on whether they are uni- or multi-cellular, respectively, to reduce the number of false predictions. Moreover, the host proteome is filtered for proteins expressed in selected cellular localizations and tissues supporting the parasite growth. We evaluated the inferred interactions by analyzing the enriched biological processes and pathways in the predicted networks and their association with known parasitic invasion and evasion mechanisms. The resulting PPI networks were compared across parasites to identify common mechanisms that may define a global pathogenic hallmark. We also provided a study case focusing on a closer examination of the human-S. mansoni predicted interactome, detecting central proteins that have relevant roles in the human-S. mansoni network, and identifying tissue-specific interactions with key roles in the life cycle of the parasite. The predicted PPI networks can be visualized and downloaded at http://orthohpi.jensenlab.org.

Parasites and allergy: Observations from Brazil.

Brazil is a middle-income country undergoing the epidemiological transition. Effects of changes in daily life habits and access to clean water, sanitation and urban services on a growing urban population have contributed to a double burden of both infectious and noncommunicable chronic diseases. Studies have indicated that parasite infections may modulate the human immune system and influence the development of allergic conditions such as asthma. However, there is no consensus in the published literature on the effects of parasitic infections on allergy, perhaps as a consequence of factors determining the epidemiology of these infections that vary between populations such as age of first infection, duration and chronicity of infections, parasite burden and species, and host genetic susceptibility. In this review, we discuss the observations from Brazil concerning the relationship between parasite infections and allergy.

Nasopharyngeal linguatulosis or halzoun syndrome: clinical diagnosis and treatment.

OBJECTIVE: Halzoun syndrome, also known as nasopharyngeal linguatulosis, is a rare entity that is mostly prevalent in Eastern Mediterranean countries. The consumption of raw ovine liver and lymph nodes infested with Linguatula serrata nymphs remains a major cause of the nasopharyngeal symptoms and discomfort associated with the disease. Halzoun syndrome is a clinical diagnosis based on history and presentation. METHODS: Treatment of this disease is still debated; however, our experience reveals that alcohol gargle can be a good option. Proper counselling on the hazards of eating raw liver in endemic areas is needed. RESULTS: Moreover, physicians should be aware of the sequence of events in the disease in order not to delay or miss the diagnosis. CONCLUSIONS: This communication presents a rare Lebanese case of Halzoun syndrome that offers medical implications in the clinical diagnosis and treatment of the nasopharyngeal symptoms of this syndrome, with a review of the literature.

Nasopharyngeal linguatulosis or halzoun syndrome: clinical diagnosis and treatment

SUMMARY Halzoun syndrome, also known as nasopharyngeal linguatulosis, is a rare entity that is mostly prevalent in Eastern Mediterranean countries. The consumption of raw ovine liver and lymph nodes infested with Linguatula serrata nymphs remains a major cause of the nasopharyngeal symptoms and discomfort associated with the disease. Halzoun syndrome is a clinical diagnosis based on history and presentation. Treatment of this disease is still debated; however, our experience reveals that alcohol gargle can be a good option. Proper counselling on the hazards of eating raw liver in endemic areas is needed. Moreover, physicians should be aware of the sequence of events in the disease in order not to delay or miss the diagnosis. This communication presents a rare Lebanese case of Halzoun syndrome that offers medical implications in the clinical diagnosis and treatment of the nasopharyngeal symptoms of this syndrome, with a review of the literature.

RESUMO Esta comunicação apresenta um caso libanês raro de síndrome de Halzoun que oferece implicações médicas no diagnóstico clínico e no tratamento dos sintomas nasofaríngeos desta síndrome, com uma revisão da literatura. A síndrome de Halzoun, também conhecida como linguatulose nasofaríngea, é uma entidade rara predominante nos países do Mediterrâneo Oriental. O consumo de linfonodos ovinos e linfáticos ovinos infestados com ninfas Linguatula serrata continua a ser uma das principais causas dos sintomas nasofaríngeos e do desconforto associado à doença. A síndrome de Halzoun é um diagnóstico clínico baseado na história e na apresentação. O tratamento dessa doença ainda é debatido; no entanto, nossos resultados revelam que o gargarismo de álcool pode ser uma boa opção. É necessário um aconselhamento adequado sobre os perigos de comer fígado cru em áreas endêmicas. Além disso, os médicos devem estar cientes da sequência de eventos na doença, a fim de não atrasar ou perder o diagnóstico.

Caenorhabditis elegans: nature and nurture gift to nematode parasitologists.

The free-living nematode Caenorhabditis elegans is the simplest animal model organism to work with. Substantial knowledge and tools have accumulated over 50 years of C. elegans research. The use of C. elegans relating to parasitic nematodes from a basic biology standpoint or an applied perspective has increased in recent years. The wealth of information gained on the model organism, the use of the powerful approaches and technologies that have advanced C. elegans research to parasitic nematodes and the enormous success of the omics fields have contributed to bridge the divide between C. elegans and parasite nematode researchers. We review key fields, such as genomics, drug discovery and genetics, where C. elegans and nematode parasite research have convened. We advocate the use of C. elegans as a model to study helminth metabolism, a neglected area ready to advance. How emerging technologies being used in C. elegans can pave the way for parasitic nematode research is discussed.

Analysis of the accuracy of different laboratory methods for the diagnosis of intestinal parasites from stray and domiciled cats (Felis catus domesticus) in Goiânia, Goiás, Brazil / Análise da acurácia de diferentes técnicas parasitológicas no diagnóstico de parasitos entéricos de gatos (Felis catus domesticus) errantes e domiciliados em Goiânia, Goiás, Brasil

Cats are carriers of zoonotic agents to humans, including intestinal parasites. The purpose of this study was to analyze the accuracy of different laboratory methods for the diagnosis of intestinal parasites. Fecal samples were processed by the Willis, Sheather, Faust and Hoffman-Janer-Pons-Lutz (HJPL) methods. Accuracy analysis was performed determining the sensitivity, specificity, positive and negative predictive value and Kappa. A total of 149 fecal samples were collected, 65 from stray cats and 84 from domiciled cats. The prevalence of intestinal parasites in stray cats was 60% while in domiciled cats it was 17%. In the analysis of accuracy, the techniques that showed the greatest accuracy for Ancylostomids were Willis and Faust, for Cystoisospora spp. Sheather with Faust or HPJL, and Toxoplasma gondii/Hammondia hammondi the association between Willis and Faust. Therefore, for a reliable evaluation of the prevalence of intestinal parasites, at least two different techniques should be used in parasitological exams of feces.(AU)

Gatos são veiculadores de agentes zoonóticos para o homem, entre eles os parasitos intestinais. O objetivo foi analisar a acurácia de diferentes métodos laboratoriais para o diagnóstico de parasitos entéricos. As amostras de fezes foram processadas pelos métodos de Willis, Sheather, Faust e Hoffman-Janer-Pons-Lutz (HJPL). A análise de acurácia foi realizada determinando a sensibilidade, especificidade, valor preditivo positivo e negativo e índice Kappa. Foram coletadas 65 amostras de fezes de gatos errantes e 84 amostras de gatos domiciliados, total de 149 amostras. A prevalência de parasitos entéricos nos errantes foi 60% e nos domiciliados 17%. Na análise de acurácia as técnicas que associadas apresentaram maior acurácia para Ancilostomídeos foram Willis e Faust, para Cystoisospora spp. Sheather com Faust ou HPJL, e para Toxoplasma gondii/Hammondia hammondi a associação entre Willis e Faust. Portanto, para uma avaliação fidedigna da prevalência de parasitos entéricos, deve-se usar no mínimo duas técnicas diferentes ao realizar os exames parasitológicos de fezes.(AU)