Neida Lucia Conrad’s research while affiliated with Federal University of Pelotas and other places

The cytokine microenvironment is crucial in generating and polarizing the immune response. A means of monitoring this environment would be of great value for better understanding Toxocara canis immune modulation. The aim of this study was to analyze the dynamics of cytokine transcription ex vivo, during early (24-48 hours) and late (15-30 days) times post-infection, in the mesenteric lymph nodes, spleen and intestinal mucosa of Balb/c mice experimentally infected with T. canis larvae. Mice in the treated group were infected with 100 third-stage larvae (L3), whereas mice in the control group were not infected. Analyses were performed at different times: 24-48 hours post-infection (HPI), 15-30 days post-infection (DPI). IL4, IL10, IL12 and Ym1 mRNA transcriptions were analyzed through qPCR. This study showed cytokine transcription mediated by migrating larvae in the mesenteric lymph nodes and spleen at 24-48 HPI, whereas cytokine transcription in the intestinal mucosa was observed only at late times (15-30 DPI). These results suggest that the T. canis larvae migration during infection might play a role in cytokine dynamics. Since the cytokine microenvironment is crucial in modulating immune response, knowledge of cytokine dynamics during T. canis infections pave the way to better understand its interaction with the host.

Lawsonia intracellularis é uma bactéria Gram-negativa intracelular obrigatória que causa a Enteropatia Proliferativa Suína (EPS), uma doença economicamente importante para a suinocultura. A infecção é caracterizada pela hiperplasia da mucosa intestinal, desencadeando sinais clínicos como diarreia, perda de peso e, em alguns casos, morte súbita. A prevalência das infecções em escala mundial é difícil de ser estimada devido a presença de animais assintomáticos e difícil diagnóstico diferencial, tornando incalculáveis as perdas econômicas decorrentes da infecção. A compreensão da patogênese de L. intracellularis, especialmente como o hospedeiro responde à infecção e os fatores que influenciam para os diferentes desfechos clínicos é essencial para que intervenções apropriadas sejam realizadas. A vacinação é a melhor medida profilática contra EPS, contudo as vacinas disponíveis apresentam limitações, motivando pesquisadores à busca de novos antígenos, estratégias e sistemas de entrega vacinais que proporcionem a resposta imune protetora à L. intracellularis. Neste estudo revisamos os principais fatores relacionados à patogenicidade de L. intracellularis e os principais aspectos da resposta vacinal. Além disso, a revisão aborda o cenário de vacinas disponíveis e em desenvolvimento contra L. intracelullaris, incluindo os principais epítopos e estratégias que vem sendo estudadas.

Descoberta no final de 2019 e denominada COVID-19, a infecção pelo coronavírus SARS-CoV-2 é uma doença que impactou o mundo de diversas formas, atingindo o status de pandemia. Dentre as opções de tratamento, o soro hiperimune representou ser eficaz e de baixo custo, obtido através do fracionamento do soro a partir do sangue total contendo grande quantidade de anticorpos. Para a produção pode ser utilizada a espécie equina, que demonstra vantagens, como o volume de sangue que pode ser obtido e a facilidade de manejo. Diversos fatores individuais como a idade, o escore corporal, aspectos clínicos e hematológicos influenciam a resposta imunológica a um antígeno vacinal. O objetivo deste trabalho foi definir através de parâmetros clínicos e hematológicos os equinos com maior potencial para a produção de soro hiperimune contra o SARS-CoV-2. Para isso foram utilizados 26 cavalos hígidos, sendo realizadas coletas de sangue e obtenção de soro, para avaliação de parâmetros bioquímicos, hematológicos e monitoramento da produção de anticorpos (ELISA indireto), respectivamente. Correlacionando os dados clínicos e hematológicos com os níveis de anticorpos produzidos após 20 e 30 dias da última inoculação, observou-se que maiores níveis de anticorpos anti-SARS-CoV-2 foram produzidos por equinos machos castrados, com alta concentração de plaquetas. Concluímos que o processo de produção de soro hiperimune contra o SARS-CoV-2 causou reações inflamatórias locais e sistêmicas transitórias, porém as reações se reverteram sem causar danos relevantes aos animais. Os equinos machos castrados, quando comparados com fêmeas, produziram níveis mais elevados de anticorpos contra a SARS-CoV-2.

Invasive meningococcal disease (IMD) is a major cause of meningitis and septicaemia worldwide. Changes in serogroup predominance contribute to the unpredictable nature of the disease, with significant health impact. This study aimed to determine the epidemiological profile of IMD in Rio Grande do Sul, Santa Catarina and Paraná, three states in southern Brazil. We analysed 1024 IMD cases that had been confirmed by clinical and/or laboratory criteria and reported to the national information system for notifiable diseases between 2015 and 2019. Additionally, we calculated the proportions of serogroup and incidence by age. Of 1024 cases, 562 (55 %) were caused by serogroup C. Furthermore, serogroup W was responsible for almost half of the cases among children younger than 5 years between 2017 and 2018, with an overall incidence of 1.5 cases/100 000 infants. IMD remains a significant healthcare issue in southern Brazil despite reduced serogroup C incidence after the introduction of the meningococcal C conjugate vaccine into the childhood immunization programme. Changes in disease epidemiology were observed, and serogroup W was the most common serogroup among children younger than 5 years in 2017 and 2018. Although future cost-effectiveness studies are necessary, our results could have future implications for meningococcal vaccination programmes.

The objective of this work was to evaluate the early and late immunological modulation of an experimental infection of T. canis larvae in mice. Mice were infected with 100 infective larvae and euthanized at different period: 24, 48 hours post infection (HPI), 15- and 30 days post infection (DPI). The humoral response was evaluated by indirect ELISA. Quantitative RT–PCR (qPCR) was used to quantify the mRNA transcription of cytokines IL4, IL10, IL12 and Ym1 in the early and late infection periods. Infection with T. canis was able to generate specific total IgG at 15- and 30- DPI. Analyzing the IgG isotype revealed a significant differentiation for IgG1 compared with IgG2a, IgG2b and IgG3, characterizing a Th-2 response. Evaluating the gene transcription at the early phase of infection, higher transcription levels of IL10, IL4 and Ym1 and a downregulation of IL12 were observed. By the late phase, increased transcription levels of IL4, Ym1 and IL12 were observed, and downregulation of IL-10 transcription was observed. The data obtained suggest that during experimental infection with T. canis, the participation of the IL4, IL10, IL12 cytokines and Ym1 can play an important role in T. canis immunomodulation.

Non-conventional yeasts can be isolated from a wide range of environmental sources and are often found in the beverage industry in mixed fermentations, in which the microbial community is usually not fully known. However, it is important to know the compositions of these starter cultures because in addition to enabling reproducibility during fermentation, other properties can be discovered. Thus, the objective of this work was to identify and characterize non-conventional yeasts isolated from the environment, evaluating their probiotic potential and possible use in beer brewing. Isolates were obtained from flowers, fruits, leaves and mixed-fermentation beers, with the species being identified by PCR. Yeasts with promising activity were evaluated regarding their growth under different pHs, temperature and the presence of organic acids. To explore probiotic potential, in vitro tests were performed for antimicrobial activity and co-aggregation with food-spoiling microorganisms, auto-aggregation and survival in simulated gastrointestinal tract conditions. In this study, Pichia kluyveri (LAR001), Hanseniaspora uvarum (PIT001) and Candida intermedia (ORQ001) were selected among 20 isolates for further study. P. kluyveri was the only strain that tolerated pH 2.5. Lactic acid was not inhibitory, but acetic acid and incubation at 37 °C had partially inhibitory effects on yeast growth. All yeasts tolerated α-acids from hops and up to 1% NaCl. Our results also suggest that these isolates are able to adhere to intestinal cells and positively influence the host to combat pathogens, as they showed auto-aggregation rates > 99% and antagonistic activity to pathogenic bacteria. The yeasts tolerated gastric environment conditions, but were more sensitive to pancreatic conditions. We conclude that these non-conventional yeasts have probiotic potential and promising application in beer fermentation.

Background: Invasive meningococcal disease (IMD) remains a major public health problem associated with death and severe consequences, especially in children. However, IMD is preventable through vaccination, with vaccines available to cover five of the six most common disease-causing strains (A, B, C, X, Y, and W). Surveillance systems are necessary for monitoring IMD incidence, together with the severity and serogroup prevalence of the disease. knowledge of the prevalence of Neisseria meningitidis (Nm) serogroups in IMD is critical for adopting the best strategies for meningococcal immunization. Method: In Brazil, all IMD cases are reported to the National Disease Notification System (SINAN). The goal of this study is to evaluate the epidemiological and microbiological data retrieved from SINAN from 2007–19. Results: During this period, 251,773 cases were reported with around 9% of them progressing to death. Furthermore, in approximately 95% of cases, the serogroup was not identified. Conclusions: Hence, improving the SINAN information is crucial for guiding future IMD prevention, such as vaccination and control strategies.