RESUMO
An effective pathogen has the ability to evade the immune response. The strategies used to achieve this may be based on the direct action of virulence factors or on the induction of host factors. Myeloid-derived suppressor cells (MDSCs) are immune cells with an incredible ability to suppress the inflammatory response, which makes them excellent targets to be exploited by pathogenic bacteria, viruses, or parasites. In this review, we describe the origin and suppressive mechanisms of MDSCs, as well as their role in chronic bacterial, viral, and parasitic infections, where their expansion seems to be essential in the chronicity of the disease. We also analyze the disadvantages of current MDSC depletion strategies and the different in vitro generation methods, which can be useful tools for the deeper study of these cells in the context of microbial infections.
Assuntos
Infecções Bacterianas/imunologia , Células da Medula Óssea/imunologia , Citocinas/imunologia , Células Supressoras Mieloides/imunologia , Doenças Parasitárias/imunologia , Viroses/imunologia , Animais , Infecções Bacterianas/genética , Infecções Bacterianas/microbiologia , Células da Medula Óssea/microbiologia , Doença Crônica , Citocinas/genética , Expressão Gênica , Humanos , Evasão da Resposta Imune , Imunidade Inata , Linfócitos/imunologia , Linfócitos/microbiologia , Monócitos/imunologia , Monócitos/microbiologia , Células Supressoras Mieloides/microbiologia , Neutrófilos/imunologia , Neutrófilos/microbiologia , Doenças Parasitárias/genética , Doenças Parasitárias/microbiologia , Transdução de Sinais , Viroses/genética , Viroses/microbiologiaRESUMO
PURPOSE OF REVIEW: Asthma in Latin America is a growing public health problem and seems to be most prevalent and cause most morbidity among poor urban populations. This article will review the findings of recent human studies of the associations of asthma prevalence in Latin America with factors associated with poverty and inequality including childhood infections, stress, environment, nutrition and diet. RECENT FINDINGS: Most asthma in childhood in Latin America is nonatopic and has been associated with exposures related to environmental dirt, diet and psychosocial distress. These factors are strongly linked to poverty and inequality. Interestingly, infections with bacterial, viral and parasitic pathogens in childhood appear to attenuate atopy in childhood but have no effect on asthma symptoms. There are biologically plausible mechanisms by which dirt exposures (e.g. endotoxin and other microbial products and nonmicrobial irritants), diet and obesity and psychosocial stress may cause airways inflammation. SUMMARY: Most childhood asthma in Latin America is nonatopic for which important risk factors are those of poverty including poor hygiene (i.e. dirt), poor diet and obesity and psychosocial stress. There is evidence that exposures to infections in early childhood reduce atopy but not asthma. Research is needed to identify causes of nonatopic asthma that may be suitable for primary prevention or other public health intervention strategies for asthma in Latin America.
Assuntos
Asma/epidemiologia , Infecções Bacterianas/epidemiologia , Pobreza/estatística & dados numéricos , Viroses/epidemiologia , Asma/microbiologia , Dieta/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Feminino , Humanos , América Latina/epidemiologia , Masculino , Obesidade/epidemiologia , Obesidade/microbiologia , Doenças Parasitárias/epidemiologia , Doenças Parasitárias/microbiologia , Fatores de Risco , Microbiologia do Solo , Estresse Psicológico/epidemiologia , Estresse Psicológico/microbiologia , Urbanização , Violência/estatística & dados numéricosRESUMO
Pseudomiasis es el término empleado cuando se considera que las larvas y/o huevos de moscas se adquieren accidentalmente per os y atraviesan con inmediatez a lo largo del tracto digestivo. Se documenta un caso de una pseudomiasis intestinal por larvas de Eristalis tenax (Diptera: Syrphidae) en una paciente femenina de 39 años de edad, proveniente de un sector periférico de la ciudad de Coro, estado Falcón, Venezuela. La paciente observó inmediatamente la presencia de la larva viva en sus heces. Aunque refirió sufrir eventualmente de cólicos, al examen físico se presentó normal. La paciente aparentemente no sufre de trastornos mentales, y posee un nivel socioeconómico bajo. El presente trabajo constituye el primer reporte documentado de una pseudomiasis entérica por E. tenax en la zona semiárida del estado Falcón, en la región nor-occidental de Venezuela.
Pseudomyiasis is the term used for the accidental entrapment of swallowed fly maggots and/or eggs immediately passing through the digestive tract. We report a case of intestinal pseudomyasis caused by the larvae of the cosmopolitan drone fly Eristalis tenax (Diptera: Syrphidae) in a 39 year old woman, resident in a suburban sector from Coro city, Falcon state, Venezuela. The patient immediately noticed a living larva in her stool. Although patient referred eventually became colic, her physical examination was normal, with no mental disturbance. She was in a low socioeconomic level. This is the first report of an enteric pseudomyasis by E. tenax in the semiarid zone of Falcon state, in the northwestern region of Venezuela.
Assuntos
Humanos , Adulto , Feminino , Miíase/diagnóstico , Miíase/epidemiologia , Miíase/etnologia , Miíase/microbiologia , Miíase/parasitologia , Miíase/patologia , Miíase/transmissão , Dípteros/parasitologia , Doenças Parasitárias/etnologia , Doenças Parasitárias/fisiopatologia , Doenças Parasitárias/microbiologiaRESUMO
El mecanismo adaptativo entre Leishmania y Trypanosoma ante la competencia por los recursos nutricionales en ambientes compartidos ha sido pobremente investigado. En particular, el estudio de la conducta trófica entre Leishmania chagasi y Trypanosoma cruzi podría contribuir al entendimiento de situaciones de gran relevancia médica en humanos, como son las infecciones mixtas por ambos tripanosomatídeos. En este trabajo se establecieron cultivos axénicos puros de Leishmania chagasi y Trypanosoma cruzi, así como cultivos axénicos mixtos (L. chagasi + T. cruzi) en médio BHI. Se registraron los cambios de dinámica poblacional (organismos por mililitro), la evolución de la estructura de las poblaciones, las variaciones de las concentraciones de colesterol, glucosa y proteínas totales, así como los cambios de pH en el medio de cultivo. El manejo cuantitativo de los conjuntos numéricos generados experimentalmente se abordó con técnicas univariadas (Análisis de la Varianza) y multivariadas (Análisis Discriminante Múltiple). Los resultados demuestran diferencias estadísticas significativas entre las medias de los parámetros considerados y prueban que el comportamiento in vitro investigado en el cultivo mixto L. chagasi T. cruzi difiere taxativamente del estudiado en los cultivos puros de L. chagasi y T. Cruzi
The adaptive mechanisms betweenLeishmania and Trypanosoma facing the competencefor the nutritional resources in shared environmentshave been poorly investigated. Particularly, thestudy of the trophic behavior between Leishmaniachagasi and Trypanosoma cruzi could contribute tothe understanding of relevant medical situations, asmixed human infections. In this work pure axeniccultures of Leishmania chagasi and Trypanosomacruzi, as well as mixed cultures (L. chagasi + T.cruzi) were established in BHI medium. Changes ofpopulation dynamics (organisms/mL), the evolutionof the populations structure, the variations of theconcentration of cholesterol, glucose and total proteins,as well as the changes of the mediums pH wereregistered. The generated numerical sets were tackledwith univariate (Analysis of Variance) and multivariate(Multiple Discriminant Analysis) techniques. Theresults demonstrate significant statistical differencesbetween the media of the considered parameters andprove that the in vitro behavior investigated in theL. chagasi T. cruzi mixed culture precisely differsfrom the L. chagasi and T. cruzi pure cultures
Assuntos
Humanos , Masculino , Feminino , Doenças Parasitárias/microbiologia , Leishmania infantum/patogenicidade , Trypanosoma cruzi/patogenicidade , Cultura de VírusRESUMO
Describir y evaluar cinco brotes epidémicos de leishmaniasis tegumentaria americana (LTA) en grupos familiares de los estados Miranda y Aragua y de la República de Colombia. Trece pacientes de grupos familiares diferentes acudieron al Instituto de Medicina Tropical por lesiones ulcerosas en regiones anatómicas expuestas; siete del sexo masculino en edades entre 2 y 66 años. La leishmanina, los anticuerpos fluorescentes anti-leishmania y los frotis por aposición de segmentos de piel de las úlceras revelaron la presencia del parásito leishmania spp. Se efectuaron exámenes bioanalíticos y cardiovasculares recomendados para el tratamiento con antimoniatos pentavalentes. Siete pacietes fueron tratados ambulatoriamente con meglumina intramuscular a la dosis de 3000 mg/día en series terapéuticas de 10 días con una segunda serie luego del reposo de 10 días. Una paciente adulta recibió tres series de AM, la última de ellas de 4500 mg/kg/día 10 días en hospitalización. Cinco niños fueron hospitalizados y recibieron AM a la dosis de 70 mg/día/10 días con reposo intermedio y una segunda serie. Los pacientes respondieron adecuadamente a la terapia empleada con la cicatrización completa de los procesos ulcerosos. La LTA siguen adquiriéndola pobladores y viajeros de las áreas rurales de Venezuela y Colombia y frecuentemente se presenta como brotes epidémicos familiares, lo cual facilita el diagnóstico presuntivo. El caso índice permite el diagnóstico de la enfermedad entre otros familiares. Los casos tratados comprueban una vez más las ventajas terapéuticas de la meglumina en LTA.
Leishmaniasis is an infectious disease acquired with relative frequency in the rural areas of Venezuela and Colombia. When there is the antecedent of another member of the family with a similar symptom "at home there is somebody with a similar ulcer" is a frequent statement that facilitates the diagnosis. To describe and evaluate five epidemic autbreaks of cutaneous leishmaniasis of the New World (CLNW) in family groups of Miranda and Aragua states in Venezuela and North Santander Department in Colombia, including diagnosis and treatment with meglumine. This disease is relatively frequently acquired by inhabitants and travelers to these geographical regions. Thirteen patients of different family groups, attended to the "Instituto de Medicina Tropical" (IMT) and to the "Hospital Universitario de Caracas" (HUC) presenting an ulcerative lesión on an exposed area of skin, compatible with the clínical diagnosis of this parasitic disease. Seven patients were females with age between 2 and 66 years. Laboratory diagnostic exams included the intradermal reaction test "leishmanina" serology tests for determination of antibodies anti-leismania and apposition smear from the ulcers stained by the Giemsa method, resulted positive for the infection produced by parasites of the species Leishmania spp. Six patients adults received treatment as outpatients with two series of the pentavalent antimony meglumine at a dose of 3000 mg/day during 10 days, one patient received the dose of 4500 mg/day as a last series of treatment. Children were given a dose of meglumine of 70 mg/kg/day, in series of treatment with their respective rest period. All patients responded adequately. Once again, we can demonstrate the advantages of the treatment of CLNW with the pentavalent antimony meglumine.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Doenças Parasitárias/microbiologia , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/terapia , Doenças Transmissíveis/etiologia , Infectologia , Zona RuralRESUMO
In order to know the agents and foods related more frequently with food-borne disease outbreaks, we reviewed all the outbreaks studied between 1980 and 1989 by the National Laboratory of Public Health. A total of 79 outbreaks of food-borne diseases of microbial origin were reviewed. The causative agent was identified in 50 (73%) outbreaks. Twenty-four per cent of the outbreaks occurred in parties, 10.3 per cent in school or nurseries, 8.6 per cent in restaurants and 8.6 per cent in hospitals. Staphylococcus aureus was the most common agent, causing 48.2 per cent of the outbreaks. Salmonella enterica was involved in 34 per cent of them. The most frequent serovar was typhimurium. Foods involved were: cheese in 29.3 per cent of the cases; cakes in 15.5 per cent; cooked meat in 15.1 per cent; milk in 13.8 per cent; and fish and seafood in 7.0 per cent of the cases. Since the number of studied incidents represents only a small proportion of all the outbreaks occurring in the country, the constant exchange of information among the laboratories which work on the problem and the promotion of the health care team are necessary in order to improve the epidemiologic surveillance systems and the study and prevention of food-borne disease and food poisoning outbreaks.
Assuntos
Infecções Bacterianas/epidemiologia , Infecções Bacterianas/etiologia , Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/etiologia , Doenças Parasitárias/complicações , Doenças Parasitárias/epidemiologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/parasitologia , Surtos de Doenças/estatística & dados numéricos , Microbiologia de Alimentos , Parasitologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/parasitologia , Humanos , Incidência , México/epidemiologia , Doenças Parasitárias/microbiologia , Doenças Parasitárias/parasitologiaRESUMO
The pattern of microbial diseases in Jamaican children is reviewed on the basis of specimens received at the Microbiology Department of the University of the West Indies. Data of infant morbidity and mortality in Jamaica in previous years leads one to speculate that suitable immunizations may have prevented much of this illness. Enteric organisms of the Salmonella, Shigella and Pathogenic Bacterium coli groups were frequently isolated from children with diarrhoea who were under two years of age. Typhoid fever was comparatively rare. Hemophilus infleunza type b still remains the commonest cause of bacterial meningitis. Corynebacterium diphtheria gravis has replaced the intermedius type as the species prevalent in nosapharyngeal diphtheria. Eleven viruses were isolated from one hundred and three specimens received from children. These were identical as poliomyelitis virus in seven cases, herpes simplex virus in two, coxsackie virus in one and chicken pox virus in another. In a study of gastroenteritis, twenty-two of forty-five pools of six rectal swabs each, showed cytopathological changes in human thyroid while thirteen control pools proved to be negative. The predominant parasites found in children were Ascaris, Trichuris, Hookworm and Giardia lambia. The incidence was significantly higher in rural areas (AU)