Immune homeostasis to microorganisms in the guts of triatomines (Reduviidae): a review

Bacteria, fungi and parasites are in constant contact with the insect gut environment and can influence different aspects of the host gut physiology. Usually, some of these microorganisms develop and survive in the digestive tract. Therefore, the gut environment must be able to tolerate certain populations of these organisms for the establishment of interactions between non-pathogenic bacteria, parasites and the gut. This review provides a brief overview of the biological and molecular mechanisms that microorganisms use to interact with the gut epithelia in mosquitoes and speculates on their significances for the development of bacteria and Trypanosoma cruzi in the guts of triatomines.

In vivo assessment of possible probiotic properties of Zymomonas mobilis in a Wistar rat model

In recent years the incorporation of probiotic bacteria into foods has received increasing scientific interest for health promotion and disease prevention. The safety and probiotic properties of Zymomonas mobilis CP4 (UFPEDA-202) was studied in a Wistar rat model fed the 10(9) colony forming units (cfu)/mL-1 of the assayed strain for 30 days. No abnormal clinical signs were noted in the group receiving viable cells of Z. mobilis and water (control) during the period of the experiment. There were no significant difference (p > 0.05) in feed intake and weight gain among mice fed the Z. mobilis in comparison to the control group. No bacteria were found in blood, liver and spleen of any animals. Mice receiving Z. mobilis showed significantly differences (p < 0.05) in total and differential leucocytes count, excepting for neutrophils, after the experimental period. Otherwise, it was not found in control group. Histological examination showed that feeding mice with Z. mobilis caused no signs of adverse effects on gut, liver and spleen. From these results, Z. mobilis CP4 (UFEPEDA-202) is likely to be nonpathogenic and safe for consumption, and could have a slight modulating effect on immunological performance in mice.

Prevalencia del complejo entamoeba histolytica/entamoeba dispar en pacientes con síntomas gastrointestinales de diarrea procedentes de Cumaná estado Sucre / Prevalence of entamoeba histolytica/entamoeba dispar in patients with gastrointestinal symptoms of diarrhea and who come from Cumaná Sucre state

Entamoeba histolytica es considerada un problema de salud pública debido a su alta prevalencia y las consecuencias para los individuos, especialmente a niños quienes puede considerar incluso la muerte. Pocos estudios se han llevado a cabo sobre la prevalencia de estas especies en el nororiente de Venezuela, por lo que se planteó analizar 400 muestras de heces de pacientes con síntomas gastrointestinales de diarrea de ambos sexos y diferentes grupos etarios para determinar la prevalencia del complejo entamoeba histolytica/entamoeba dispar y su asociación con otros parásitos además de su asociación con algunos parámetros epidemiológicos. Las muestras fueron analizadas por métodos coproparasitológicos usando solución salina fisiológica al 0,85 por ciento, lugol coloración tricrómica, sangre oculta y concentración por Ritchie. A cada paciente se le aplicó una encuesta para obtener datos clínicos y epidemiológicos. Se encontró una prevalencia de 16,0 por ciento (n=64) para el complejo entamoeba histolytica/entamoeba dispar. Otros parásitos frecuentes fueron blastocystis hominis 19,3 por ciento (n=77), entamoeba coli 9,3 por ciento (n=37), endolimax nana 8,0 por ciento (n=32), giardia lamblia 5,8 por ciento (n=23), trichuris trichiuria 4,0 por ciento (n=16), ascaris lumbricoides 3,8 por ciento (n=15). Un 15,5 por ciento de los pacientes estaban poliparasitados, mientras que 37,0 por ciento mostraron un único parásito. Blastocystis hominis resultó ser el parásito mayormente asociado con complejo entamoeba histolytica/entamoeba dispar 10,9 por ciento (n=7). La sintomatología fue variable entre lo que podemos mencionar vómitos (26,6 por ciento), nauseas (39,1 por ciento), dolor abdominal (68,8 por ciento), fiebre (28,1 por ciento) y flatulencia (65,6 por ciento). No se encontró asociación significativa entre la presencia de las amibas y el sexo (X²=16,63, P<0,05), pero sí con edad (x²=16,63, p<0,05), siendo el grupo etario 10-19 años el más efectado. Las cifras de prevalencia de parásitos intestinales, especialmente para el complejo entamoeba histolytica/entamoeba dispar, demuestran que existe un problema importante de salud que debe ser abordado por las autoridades sanitarias del estado

Midgut antibodies reduce the reproductive capacity of Anopheles stephensi (Diptera: Culicidae).

Rabbits immunized with polypeptides of midgut of glucose fed A. stephensi resulted in high titer of antibodies (10(4)-10(6)) as detected by ELISA. Effect of antisera on fecundity, hatchability and engorgement was investigated. Fecundity was reduced drastically (62.4%). Eight polypeptides were recognized by the antisera raised against midgut tissues viz., 92, 85, 55, 52, 45, 38, 29 and 13 kDa. Cross reactivity of these antibodies with different tissues of A. stephensi as well as different species of Anopheles was also analyzed. The results indicated that anti-mosquito midgut antibodies had the potential to disrupt the reproductive physiology of mosquitoes in view of the present study, there is a need for further investigation with target antigens.

Intestinal infections.

Gastrointestinal infections are the significant cause of childhood morbidity and mortality worldwide. Gastrointestinal infections reflects the balance between the intrinsic virulence factors of the enteropathogens and host mechanisms which defend against enteric infections. Host defense factors include gastric acidity, intestinal motility, the normal indigenous intestinal microflora, mucous secretion, and specific mucosal and systemic immune mechanisms. Majority of GI infections are self limited so on one hand antibiotics are not needed and on the other hand the irrational use of antibiotics produces resistant strains. Acute diarrheal diseases which are one of the important intestinal infections, in majority of the cases are viral and have short course. Antibiotics are recommended only in specific cases and in immunocompromised individuals. Gastrointestinal disease is one of the most common manifestations of HIV infection. The gastrointestinal tract contains abundant quantities of lymphoid tissue and is likely to function as a reservoir of HIV infection, a site of profound immune dysregulation, and a target for opportunistic infections. In this situation specific antibiotics are indicated.

Midgut specific immune response of vector mosquito Anopheles stephensi to malaria parasite Plasmodium.

Innate immune-related polypeptides expression in midgut in the ageing vector mosquito A. stephensi following infection by malaria parasite, Plasmodium yoelii yoelii has been studied. Twenty polypeptides were induced by an infected blood meal during various stages of adult life. A 24 kDa polypeptide was induced generally in most of the stages. Maximum parasite induced polypeptides i.e. 22, 33, 111, 122, 127, 140, 143 and 146 kDa were found in 5 days of post blood feeding (PBF) which coincides with the presence of oocysts on the midgut. However, in addition, three polypeptides in 11 days PBF and 8 polypeptides in 20 days PBF were also induced due to parasite infection in aged mosquitoes. Quantitatively, the amount of soluble proteins in the midgut in oocyst-sporozoite-positive mosquitoes was always less as compared to their normal counterparts. The parasite evidently elicits defined immune responses by inducing specific polypeptides in the midgut of the mosquito.

A rare case of variable immune deficiency with type II dysgammaglobulinaemia, light chain defect, gut associated IgA deficiency and progressive neutropenia.

This report describes in detail an unusual variant of a common variable immunodeficiency disease in a seven-year-old boy. The unique features were progressive neutropenia due to defective myelopoiesis, serum IgG and IgA deficiencies, defective immunoglobulin light-chain synthesis, absence of secretory IgA and IgM gammopathy. He had been born healthy, but following a thermal injury at the age of 1 1/2 years, he suffered recurrent attacks of sinopulmonary and urinary tract infections, enteritis due to enteropathogenic E. coli, Giardia lamblia and E. histolytica, developed pulmonary tuberculosis and died of deep mycotic infection of the oral cavity and obstruction of the bronchial tree. The cause of the defective myelopoiesis could not be determined, but it might have been due to prolonged sulphomamide therapy administered for controlling his persistent urinary tract infection due to paraphymosis.