RONALDO CESAR BORGES GRYSCHEK
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina - Docente
LIM/06 - Laboratório de Imunopatologia da Esquistossomose e outras Parasitoses, Hospital das Clínicas, Faculdade de Medicina
LIM/06 - Laboratório de Imunopatologia da Esquistossomose e outras Parasitoses, Hospital das Clínicas, Faculdade de Medicina
17 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 17
- Seroprevalence and associated risk factors of strongyloidiasis in indigenous communities and healthcare professionals from Brazil(2023) SANTAREM, Vamilton Alvares; DOLINE, Fernando Rodrigo; SANTOS, Joao Henrique Farinhas dos; FERREIRA, Isabella Braghin; GOMES, Bruna Barroso; MEISEL, Dirce Mary Correa; BIONDO, Leandro Meneguelli; LESCANO, Susana Angelica Zevallos; GRYSCHEK, Ronaldo Cesar Borges; GIUFFRIDA, Rogerio; SANTOS, Andrea Pires dos; KMETIUK, Louise Bach; PAULA, Fabiana Martins de; BIONDO, Alexander WelkerAuthor summaryHuman strongyloidiasis, caused mainly by nematoda Strongyloides stercoralis, with estimate of infecting around 613.9 million people worldwide, and may play a pivotal role in causing morbidity in aboriginals and indigenous populations worldwide. Nevertheless, prevalence and risk factors for Strongyloides stercoralis in Brazilian indigenous populations remains to be fully established. The present study was the first comparative report of S. stercoralis seroprevalence in indigenous population and healthcare professionals. A high seroprevalence to Strongyloides stercoralis in indigenous communities of Brazil along with even higher exposure of healthcare professionals was reported and should be considered as vulnerability and health worker exposure. Male and adult indigenous persons were more likely seropositive as associated risk factors, while having septic tank as a sanitary facility represented a protective factor for S. stercoralis exposure. Thus, the present study has alerted for the public health concerns of strongyloidiasis in such vulnerable populations, particularly when lacking sanitation conditions. Finally, a further One Health approach may contribute for better understanding the strongyloidiasis exposure including the environmental, animal, and human components to battle this important parasitic neglected disease in indigenous communities. Strongyloides stercoralis, a pathogenic roundworm, is considered endemic in several tropical and subtropical areas worldwide. Indigenous populations have the highest soil-transmitted helminthiases-related mortality rates, but the prevalence and risk factors associated with S. stercoralis in Brazilian indigenous populations have not been established. Thus, the present study aimed to assess the seroprevalence and associated risk factors for S. stercoralis in indigenous communities and the healthcare professionals serving them in Brazil. Indigenous populations living in nine communities and healthcare professionals were tested for anti- S. stercoralis antibodies by ELISA. A questionnaire was used to assess socio-epidemiological information. Associated risk factors for seropositivity were tested by chi-square or Fisher's exact tests, using bivariate analyses and multivariate logistic regression. Overall, 174/463 (37.6%; CI 95%: 33.3-42.1) indigenous persons and 77/147 (52.4%; 95% CI: 44.3-60.3) healthcare professionals were seropositive for anti- S. stercoralis antibodies. Seropositivity among the two groups was statistically significant (p = 0.0016; OR = 0.547; 95% CI: 0.376-0.796) and revealed that healthcare professionals were 1.83 times more likely to be seropositive. The multivariate analysis showed that being male or being adult were also risk factors, while having a septic tank as a sanitary facility represented a protective factor for S. stercoralis exposure in indigenous persons. None of the variables evaluated were associated with S. stercoralis exposure in the professional group. The study herein has reported a high seroprevalence to Strongyloides stercoralis in indigenous communities of Brazil and healthcare professionals, warning for potential public health concerns of strongyloidiasis in such populations.
- Immunoreactivity of proteins within 30-40 kDa range during the acute and the recovery phases in rats experimentally infected with Strongyloides venezuelensis(2020) FONSECA, Priscilla Duarte Marques; CORRAL, Marcelo Andreeta; MEISEL, Dirce Mary C. Lima; LEVI, Debora; NASCIMENTO, Rafael Correa; CASTRO-BORGES, William; GRYSCHEK, Ronaldo; COSTA-CRUZ, Julia Maria; PAULA, Fabiana Martins deIn experimental infection with Strongyloides venezuelensis, the acute and recovery phases can be distinguished, unlike human infections caused by Strongyloides stercoralis. The objective of this study was to evaluate the production of anti-Strongyloides IgG antibodies and the recognition of immunogenic protein bands during the acute and the recovery phases in rats experimentally infected with S. venezuelensis. Rats were infected subcutaneously with 400 or 4,000 S. venezuelensis infective larvae. The acute phase was characterized by elimination of a large number of eggs in the faeces on days 6-14 post infection; the recovery phase was characterized by the resolution of the infection between days 30 and 35 post infection. Differences in IgG levels were observed in the acute and the recovery phases. Different antigenic fractions were recognized in both phases of infection. It is concluded that proteins within the 30-40 kDa range are immunoreactive markers for both the acute and the recovery phases in rats experimentally infected with S. venezuelensis, particularly using membrane antigen.
- Culture isolation and molecular identification of Blastocystis sp. in Brazilian human isolates: preliminary results(2020) MELO, Gessica Baptista de; ROLDAN, William; MALTA, Fernanda de Mello; LESCANO, Susana Angelica Zevallos; CASTILHO, Vera Lucia; GONCALVES, Elenice Messias Do Nascimento; PAULA, Fabiana Martins de; GRYSCHEK, Ronaldo Cesar BorgesBlastocystis sp. is a protist commonly found in stool samples of humans and animals. Biological and genetic factors of this organism remain controversial. The present study aimed to develop and implement the Blastocystis in vitro culture of Brazilian human isolates for routine use. The fecal isolates (n = 20) were maintained in our laboratory by several passages in Pavlova's medium. Cultures were monitored every 72 h by light microscopy. Genomic DNA was extracted to identify the subtypes (STs). In most isolates, the vacuolar form was prevalent. The amoeboid, granular and cystic forms were observed during in vitro cultivation. STs 1, 2, 3. 4 and 7 were identified. Our preliminary results show the generation time and forms present in the in vitro culture of Blastocystis subtypes isolated from Brazilian human isolates. Therefore, we emphasize the use of in vitro culture as a tool in future studies for the better understanding of the biological aspects of Blastocystis sp.
- Blastocystis subtypes in patients with diabetes mellitus from the Midwest region of Brazil(2021) MELO, Gessica Baptista de; MAZZARO, Marcia Carolina; GOMES-GOUVEA, Michele Soares; SANTOS, Emelin Alves Dos; SOUZA, Laura Vilela de; ELIAS-OLIVEIRA, Jefferson; GRYSCHEK, Ronaldo Cesar Borges; RODRIGUES, Rosangela Maria; PAULA, Fabiana Martins deBlastocystis sp. is an enteric protist commonly found in human fecal samples. In Brazil, few studies have been developed, but none of them has explored the presence of Blastocystis in patients with diabetes mellitus. We evaluated the occurrence and molecular identification of Blastocystis sp. among patients with diabetes mellitus in the Midwest region, Goias State, Brazil. Genomic DNA was obtained from 175 fecal samples (99 from the diabetic group and 76 from the control group). PCR was performed using pan-Blastocystis primers from the SSU-rDNA gene. Microscopic examination revealed positivity of 12.1% and 7.9% for Blastocystis in diabetics and in controls, respectively. Amplification of Blastocystis DNA was observed in 34.4% (34 of 99) and 30.3% (23 of 76) from the diabetic and control groups, respectively. Phylogenetic analyses and BLAST searches revealed six subtypes among Blastocystis isolates in the diabetic group, represented by ST1 (38.2%), ST2 (11.8%), ST3 (35.3%), ST6 (2.9%), ST7 (2.9%) and ST8 (8.8%). In the control group, ST1 (21.8%), ST2 (21.8%), ST3 (43.5%), ST6 (4.4%) and ST8 (8.7%) were identified. This study is the first report regarding the occurrence and subtypes distribution of Blastocystis in patients with diabetes mellitus in Brazil. The results reinforce the potential risk of Blastocystis infection in patients with diabetes, in addition, it contributes to the understanding of the genetic diversity of this enigmatic organism.
- Strongyloides infection screening in transplant candidates: What is the best strategy?(2023) GRYSCHEK, Ronaldo Cesar Borges; CORRAL, Marcelo Andreetta; SITTA, Renata Barnabe; GOTTARDI, Maiara; PIERROTTI, Ligia Camera; COSTA, Silvia Figueiredo; ABDALA, Edson; CHIEFFI, Pedro Paulo; PAULA, Fabiana Martins deBackground: The potential that Strongyloides stercoralis infection has to cause major morbidity and high mortality when the disseminated form occurs in transplant patients is of particular concern.Methods: In this study, the objective was to observe S. stercoralis infection in patients who are candidates for transplantation by using parasitological, serological, and molecular techniques and to propose an algorithm for the detection of that infection in transplant candidates.Results: By parasitological techniques, 10% of fecal samples were positive. Anti-Strongyloides antibodies immunoglobulin G were detected in 19.3% and 20.7% of patients by immunofluorescence assay and enzyme-linked immunosorbent assay, respectively. S. stercoralis DNA was observed in 17.3% of samples by conventional polymerase chain reaction and 32.7% of samples by quantitative polymerase chain reaction (qPCR).Conclusion: The set of results allows us to reinforce that a positive result by parasitological techniques and/or qPCR indicates that the specific treatment should be applied. However, the improvement of diagnostic techniques may suggest changes in the screening for strongyloidiasis in these patients. image
- Characterization of subtypes of Blastocystis sp. isolated from patients with urticaria, Sao Paulo, Brazil(2019) MELO, Gessica Baptista de; MALTA, Fernanda de Mello; MARUTA, Celina Wakisaka; CRIADO, Paulo Ricardo; CASTILHO, Vera Lucia Pagliusi; GONCALVES, Elenice Messias do Nascimento; ESPIRITO-SANTO, Maria Cristina de Carvalho do; PAULA, Fabiana Martins de; GRYSCHEK, Ronaldo Cesar BorgesBlastocystis sp. is described as an enteric protist prevalent in fecal samples from humans and animals; its pathogenicity and epidemiology are still controversial. Currently, it has been associated with intestinal diseases such as irritable bowel syndrome and clinical manifestations of allergic skin, such as chronic urticaria. In the context of urticaria, it is still uncertain whether this organism is directly related to the allergic manifestation or just a common component of the intestinal microbiota. This study aimed to evaluate the occurrence and molecular diversity of Blastocystis sp. in individuals with urticaria from a dermatology outpatient clinic, Sao Paulo, Brazil. Fecal samples of 58 patients with urticaria were examined using parasitological methods; and subsequently tested by polymerase chain reaction using Blastocystis-specific primers. The subtypes (STs) and alleles (a) were determined using BLASTn and MLST tools. ST1, ST2, ST3, ST4, ST6 and mixed infection (ST1 + ST3) were identified in the patients with urticaria; ST1 (a4), ST3 (a34 and a36) and ST4 (a42) were the most prevalent. Our molecular analyses allowed an initial description of Blastocystis subtypes in patients with urticaria from Sao Paulo city, Brazil. (C) 2019 Published by Elsevier Ltd on behalf of World Federation of Parasitologists.
- Molecular diagnosis of Strongyloides stercoralis among transplant candidates(2018) PAULA, Fabiana M.; MALTA, Fernanda M.; MARQUES, Priscilla D.; MELO, Gessica B.; CORRAL, Marcelo A.; GOTTARDI, Maiara; PINHO, Joao R. R.; GONCALVES, Elenice M. N.; CASTILHO, Vera L. P.; PIERROTTI, Ligia C.; ABDALA, Edson; COSTA, Silvia F.; CHIEFFI, Pedro P.; GRYSCHEK, Ronaldo C. B.Strongyloidiasis can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection, principally in immunosuppressed patients. Our study aimed to evaluate the application of conventional polymerase chain reaction (cPCR) and real-time PCR (qPCR). Polymerase chain reaction (PCR) and real-time PCR (qPCR) targeting the 18S rRNA gene for detection of Strongyloides stercoralis infection among transplant candidates were applied in stool samples obtained from 150 transplant candidates, preliminarily analyzed by parasitological methods. S.stercoralis larvae were visualized in 15/150 (10.0%) transplant candidates by parasitological methods. DNA from S.stercoralis was amplified in 26/150 (17.3%) and 49/150 (32.7%) stool samples of transplant candidates, using cPCR and qPCR, respectively. The results suggest that molecular methods, especially qPCR, should be used as an additional tool for diagnostic of S.stercoralis infection among transplant candidates.
- Toxocara canis 30-35 kDa excretory-secretory antigen is an important marker in mice challenged by inocula containing different parasite load levels(2022) FONSECA, Gabriela Rodrigues e; CORRAL, Marcelo Andreetta; PAULA, Fabiana Martins de; MEISEL, Dirce Mary Correia Lima; GRYSCHEK, Ronaldo Cesar Borges; LESCANO, Susana Angelica ZevallosThe Western-blotting technique was applied to identify antigenic fractions of excretory-secretory Toxocara canis antigen recognized by IgG antibodies throughout an experimental infection in mice challenged by different inocula. Mice were inoculated with 5, 50 and 500 embryonated eggs and serum samples were collected 15, 30, 60, 90 and 120 days post-infection. Serum samples were analyzed using an excretory-secretory Toxocara antigen. Antibodies recognized antigenic fractions from 30 to 90 kDa. The protein fraction of 30-35 kDa was the most frequently recognized regardless of the size of inoculum and the stage of infection represented by the different collection times, but the antigenic recognition was more evident in groups infected with 50 and 500 eggs. This study presents an antigenic panel of the excretory secretory antigen of T. canis and suggests that the 30-35 kDa antigenic fraction is a promising marker of the infection and should be further explored in future studies on experimental toxocariasis.
- Evaluation of larval surface antigens from infective larvae of Strongyloides venezuelensis for the serodiagnosis of human strongyloidiasis(2023) GOMES, Bruna Barroso; GONZALES, William Henry Roldan; MEISEL, Dirce Mary Correa; GRYSCHEK, Ronaldo Cesar Borges; PAULA, Fabiana Martins deSerodiagnosis of strongyloidiasis is usually performed by ELISA for the detection of IgG antibodies due to its high sensitivity and practicality, but its main limitation is a constant source of S. stercoralis antigens. The use of S. venezuelensis as a heterologous source of antigens has facilitated several published studies on the serodiagnosis and epidemiology of human strongyloidiasis. The main objective of this study was to evaluate the diagnostic accuracy of surface cuticle antigens of infective larvae of S. venezuelensis extracted with CTAB detergent (L3-CTAB) in comparison with soluble somatic extracts (L3-SSE) using a panel of sera from immunocompetent and immunocompromised individuals, at three different cut-offs. ROC curve analysis showed that L3-CTAB had an AUC of 0.9926. At the first cut-off value (OD 450 nm = 0.214), sensitivity and specificity were 100% and 90.11%, respectively, with a diagnostic accuracy of 0.93. At a second cut-off value (OD 450 nm = 0.286), sensitivity and specificity were 70% and 100%, respectively, with a diagnostic accuracy of 0.91. However, at an alternative third cut-off value (OD 450 nm = 0.589), sensitivity and specificity were 95% and 97.8%, respectively, with a diagnostic accuracy of 0.97. Using L3-CTAB as an antigenic source, the seropositivity rate in immunocompromised patients was 28.13% (9/32) whereas a seropositivity rate of 34.38% (11/32) was found when L3-SSE was used in ELISA. Therefore, the L3-CTAB is simple and practical to obtain and was found to be highly sensitive and specific.
- A case report of COVID-19 in a patient with non-Hodgkin's lymphoma(2021) EILAMI, Owrang; LOPES, Max Igor Banks Ferreira; GRYSCHEK, Ronaldo Cesar Borges; TAGHIPOUR, KavehBackground The current literature is scarce as to the outcomes of COVID-19 infection in non-Hodgkin's lymphoma patients and whether immunosuppressive or chemotherapeutic agents can cause worsening of the patients' condition during COVID-19 infection. Case presentation Our case is a 59-year-old gentleman who presented to the Emergency Department of the Cancer Institute of Hospital das Clinicas da Universidade de Sao Paulo, Sao Paulo, Brazil on 10th May 2020 with a worsening dyspnea and chest pain which had started 3 days prior to presentation to the Emergency Department. He had a past history of non-Hodgkin's lymphoma for which he was receiving chemotherapy. Subsequent PCR testing demonstrated that our patient was SARS-CoV-2 positive. Conclusion In this report, we show a patient with non-Hodgkin lymphoma in the middle of chemotherapy, presented a mild clinical course of COVID-19 infection.