Natália Gomes de Morais

Neonatal malnutrition is an important environmental exposure factor that can influence the development and health of all body systems, including the immune system. The objective was to detect the impacts of malnutrition in critical period of development on the response Candida albicans infection. It was used 24 male rats Wistar. The animals were divided malnourished group (8% protein) or nourished group (17% protein). It was collected alveolar macrophages by bronchoalveolar lavage fluid of the rats with 90-day-old. Expression levels of the targets were performed using Real-time RT-PCR. It had lower body weights from 5 days of life, until adulthood. Macrophages collected from malnourished animals exhibit a lower expression of the Toll-Like Receptor (TLR-9), interleukin 18 (IL-18) and interleukin 33 (IL-33); however, transcription nuclear kappa B (NF- kB) and interleukin 1β (IL-1β) are expressed in systems where there is a challenge with an immunogenic stimulus (Lipopolysaccharide and Candida albicans). Nutritional reduction during the neonatal period has repercussions on body growth and defense mechanisms observed in adult life. The results revealed dysregulation of immune mediators with probable implications for the effector immune response. Thus, the response to Candida albicans was altered for neonatal malnutrition, with a high chance of progressing to tissue damage.

This study was conducted using data from the SCAALA (Social Change Asthma and Allergy in Latin America) cohort in Brazil from 2005 to 2013. We examined the seroprevalence and risk factors of toxocariasis, a parasitic infection leading to conditions such as visceral larva migrans, utilizing an indirect ELISA with T. canis antigens, alongside with data from questionnaires, eosinophil counts, sIgE to aeroallergens, IL-10 levels, and Skin Prick Test results; the research provided insights into the disease’s dynamics. The prevalence of anti-Toxocara spp. IgG increased from 48% to 53% over the studied period, with a 25% increase in new cases in 2013. The significant risk factors included age and pet exposure, while higher maternal education and living on paved streets were found to offer protection. The study uncovered a complex interaction between Toxocara spp. infection and the immune system, indicating that the infection could both trigger inflammation and modulate skin reactions. Based on these findings, the study proposed a roadmap for controlling toxocariasis, which includes strategies such as enhancing public education about the disease and preventive measures, improving environmental sanitation, strengthening veterinary control measures like pet deworming, increasing access to healthcare and screening, and implementing community-based interventions to address the identified risk factors. These measures aim to reduce the prevalence of toxocariasis and its impact on public health by addressing environmental and socioeconomic risk factors, providing a pathway to significantly reduce the burden of this parasitic infection.

In regions where sanitary conditions are poor, prophylactic administration of antiparasitic drugs is common and affects the prevalence of intestinal parasites, in spite of the environmental maintenance of their life cycle. The purpose of this study was to evaluate the prevalence of parasitic infections, patient lifestyles, health conditions and environmental sources of contamination. One hundred seventy two children and adolescents, 5 to 15 years of age of both sexes were analyzed. Data were obtained through epidemiological questionnaires, parasitological examinations using Paratest®, IgG testing for Entamoeba histolytica, and analysis of sources of contamination in living areas. The study detected a prevalence of 45.9% (79/172) parasitic infections, of which 62.0% (49/79) Entamoeba histolytica/E. dispar complex; 46.8% (37/79) Entamoeba coli; 27.8% (22/79) Giardia intestinalis; 12.7% (10/79) Endolimax nana; 10.1% (8/79) Hymenolepis nana; 8.9% (7/79) Ascaris lumbricoides and 2.5% (2/79) Trichuris trichiura. Out of the 49 samples positive for Entamoeba histolytica complex, there was only one case of antibodies to E. histolytica. The children’s life habits demonstrated inadequate food hygiene practices. These insufficient sanitary parameters revealed a general lack of information in face of an alarming situation regarding sewage and other sources of environmental contamination in 20% of the areas. The high prevalence of protozoan infections despite chemoprophylaxis, with environmental sources of contamination/risk, inadequate health conditions and the general apathy of the population suggest the ineffectiveness of current preventive practices. Thus, it is advisable that control actions include protozoa as therapeutic targets and, above all, health education as a routine practice to prevent the long-term continuance of this vicious cycle. KEY WORDS: Parasitic infections; chemoprophylaxis; environmental sources.

Desnutrição associada à giardíase em escolares: Análise de parâmetros antropométricos e socioeconômicos / Malnutrition associated with giardiasis in school children: Analysis of anthropometric and socioeconomic parameters

To investigate the effects of neonatal malnutrition followed by nutritional replacement on the signaling mechanisms developed by the inflammasome complex by analyzing the expression of the targeted TLR2, TLR4, NLRP3, caspase-1 and release of IL-1β and IL-18 by alveolar macrophages infected in vitro with Candida albicans. Male Wistar rats (n = 24), 90–120 days, were suckled by mothers whose diet during lactation contained 17 % protein in the nourish group and 8 % protein in the malnourished group. After weaning, both groups were fed a normal protein diet. Macrophages were obtained after tracheostomy, through the collection of bronchoalveolar lavage fluid. The quantification of the expression levels of targets (TLR2, TLR4, NLRP3 and caspase-1) was performed by real-time RT-PCR. Production of cytokines was performed by ELISA. The malnourished animals during lactation showed reduced body weight from the fifth day of life, remaining until adulthood. Further, the model applied malnutrition induced a lower expression of TLR4 and caspase-1. The quantification of the TLR2 and NLRP3, as well as the release of IL-1β and IL-18, was not different between groups of animals nourished and malnourished. The system challenged with Candida albicans showed high expression levels of all targets in the study. The tests demonstrate nutritional restriction during critical periods of development, although nutritional supplementation may compromise defense patterns in adulthood in a timely manner, preserving distinct signaling mechanism, so that the individual does not become widely vulnerable to infections by opportunistic pathogens.

Evaluate the effects of neonatal malnutrition on the microbicidal response and viability of in vitro macrophages infected with Staphylococcus aureus sensitive/resistant to methicillin. Male Wistar rats (n = 24) were divided into two distinct groups: nourished (rats breast-fed by mothers undergoing diet with 17 % casein) and malnourished (rats breast-fed by mothers undergoing diet with 8 % casein). Macrophages were recovered after surgical tracheostomy procedure by collecting bronchoalveolar lavage. Four systems were established: negative control, composed only by phagocytes; positive control, macrophages plus lipopolysaccharide; and two test systems, macrophages plus Staphylococcus aureus sensitive and resistant to methicillin. Plates were incubated at 37 °C for 24 h. After this period, tests for the analysis of cell viability and microbicidal response were performed. In the statistical analysis, the Student’s t and ANOVA tests were used, accepting p < 0.05. The neonatal malnutrition impaired the animals’ body weight. There was a lower expression of the inducible nitric oxide enzyme (iNOS), nitric oxide production, and viability of macrophages infected with methicillin-resistant Staphylococcus aureus. However, increased production of superoxide anion in the malnourished group was detected. Neonatal malnutrition focusing on critical periods of development promoted lower expression of iNOS, nitric oxide production, cell viability, and exacerbated reactive oxygen species production. The high levels of reactive oxygen species may favor the onset of serious and systemic infections with fatal outcome if associated with methicillin-resistant Staphylococcus aureus.