RONALDO CESAR BORGES GRYSCHEK

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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

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  • article 5 Citação(ões) na Scopus
    Diagnostic accuracy of somatic and excretory-secretory antigens from Strongyloides venezuelensis infective larvae for the immunodiagnosis of human strongyloidiasis
    (2021) GONZALES, William Henry Roldan; MEISEL, Dirce Mary Correia Lima; PAULA, Fabiana Martins de; GRYSCHEK, Ronaldo Cesar Borges
    To evaluate the diagnostic accuracy of three types of antigenic preparations from Strongyloides venezuelensis infective larvae for detection of serum IgG anti-Strongyloides antibodies by enzyme-linked immunosorbent assay (ELISA). Soluble somatic fractions (SSF) and membrane somatic fractions (MSF) and excretory-secretory (E/S) products from S. venezuelensis infective larvae were evaluated against 71 sera from individuals with strongyloidiasis, 105 sera from healthy individuals, and 84 sera from individuals with other helminth infections. Using an ELISA cut-off for 100% sensitivity, E/S products were 97.88% specific followed by MSF (93.12%) and then by SSF (85.2%). The occurrence of cross-reactivity with other helminths was 4.76% (4/84) with E/S products, 8.33% (7/84) with MSF, and 17.86% (15/84) with SSF. For a cut-off for 100% specificity, E/S products showed a sensitivity of 88.73% whereas MSF and SSF showed sensitivities of 59.15% and 53.52%, respectively. In conclusion, E/S products were the best antigenic option for the serodiagnosis of human strongyloidiasis.
  • article 0 Citação(ões) na Scopus
    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 Welker
    Author 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.
  • article 1 Citação(ões) na Scopus
    Twenty years of successful academic outreach at Nucleo de Medicina Tropical (NACE-NUMETROP/USP) in Santarem, Para
    (2021) SAID, Renato do Carmo; ASSY, Joao Guilherme Pontes Lima; SILVA, Kamila Vieira; BRANDAO, Alisson dos Santos; PINHEIRO, Olivia Campos; ESPER, Helena Rangel; GRYSCHEK, Anna Luiza de Fatima Pinho Lins; BERTOLOZZI, Maria Rita; AMATO, Valdir Sabbaga; BOULOS, Marcos; SEGURADO, Aluisio Augusto Cotrim; GRYSCHEK, Ronaldo Cesar Borges; FRANCA, Francisco Oscar de Siqueira
  • article 0 Citação(ões) na Scopus
    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 de
    In 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.
  • article 20 Citação(ões) na Scopus
    Molecular diagnosis of strongyloidiasis in tropical areas: a comparison of conventional and real-time polymerase chain reaction with parasitological methods
    (2015) PAULA, Fabiana Martins de; MALTA, Fernanda de Mello; MARQUES, Priscilla Duarte; SITTA, Renata Barnabe; PINHO, Joao Renato Rebello; GRYSCHEK, Ronaldo Cesar Borges; CHIEFFI, Pedro Paulo
    This study aimed to evaluate the use of conventional polymerase chain reaction (cPCR) and real-time quantitative PCR (qPCR) in the diagnosis of human strongyloidiasis from stool samples in tropical areas. Stool samples were collected from individuals and were determined to be positive for Strongyloides stercoralis (group I), negative for S. stercoralis (group II) and positive for other enteroparasite species (group III). DNA specific to S. stercoralis was found in 76.7% of group I samples by cPCR and in 90% of group I samples by qPCR. The results show that molecular methods can be used as alternative tools for detecting S. stercoralis in human stool samples in tropical areas.
  • article 7 Citação(ões) na Scopus
    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 Borges
    Blastocystis 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.
  • article 7 Citação(ões) na Scopus
    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 de
    Blastocystis 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.
  • article 5 Citação(ões) na Scopus
    Shotgun proteomics of Strongyloides venezuelensis infective third stage larvae: Insights into host-parasite interaction and novel targets for diagnostics
    (2020) FONSECA, Priscilla D. M.; CORRAL, Marcelo A.; COSENZA-CONTRERAS, Miguel; MEISEL, Dirce M. C. L.; MELO, Gessica B.; ANTUNES, Milena M. S.; SANTO, Maria C. E.; GRYSCHEK, Ronaldo C. B.; COSTA-CRUZ, Julia M.; CASTRO-BORGES, William; PAULA, Fabiana M.
    Strongyloides venezuelensis is an important alternative source of antigen for the serologic diagnosis of human strongyloidiasis. Proteomics techniques applied to the analysis of the protein content of infective third stage larvae (iL3) of S. venezuelensis provide a powerful tool for the discovery of new candidates for immunodiagnosis. This study presents an overview of the protein iL3 S. venezuelensis focusing on the diagnosis of strongyloidiasis. A total of 877 proteins were identified by shotgun proteomics. Many of these proteins are involved in different cellular processes, metabolic as well as structural maintenance. Our results point to a catalog of possible diagnostic targets for human strongyloidiasis and highlight the need for evaluation of uncharacterized proteins, especially the proteins within the CAP domain, transthyretin, and BTPI inhibitor domains, as a repertoire as yet unexplored in the context of strongyloidiasis diagnostic markers. We believe that the protein profile presented in this shotgun analysis extends our understanding of the protein composition within the Strongyloides genus, opening up new perspectives for research on biomarkers that may help with the diagnosis of human strongyloidiasis. Data are available via ProteomeXchange with identifier PXD013703.
  • article 1 Citação(ões) na Scopus
    A simple method for purification of Strongyloides venezuelensis eggs from rat faeces
    (2020) ROLDAN, W. H.; PAULA, F. Martins de; GRYSCHEK, R. C. B.
    The aim of this study was to develop a simple method to purify Strongyloides eggs from rat faeces using a sucrose gradient centrifugal-flotation technique. This procedure is simple, rapid and possesses a high efficiency in recovering Strongyloides eggs without faecal detritus in less than one hour, thus eliminating the use of complex apparatus and different chemical substances. The possibility of working with pure and live Strongyloides eggs opens up a wide range of future studies on the biology of this parasite. This study constitutes the first report in the scientific literature on purifying Strongyloides eggs using a sucrose density gradient.
  • article 15 Citação(ões) na Scopus
    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 Borges
    Blastocystis 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.