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Dos Santos EH, Barreira GA, Yamamoto L, Rocha MC, Rodrigues KA, Cruz MCP, Kanunfre KA, Okay TS. New Allele-Specific Oligonucleotide (ASO) amplifications for Toxoplasma gondii rop18 allele typing: Analysis of 86 human congenital infections in Brazil. Acta Trop 2023; 247:107011. [PMID: 37652181 DOI: 10.1016/j.actatropica.2023.107011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
This study aimed to detect and differentiate Toxoplasma gondii by the allele typing of its polymorphic rop18 gene. For this purpose, a novel genotyping system using allele-specific oligonucleotides (ASOs) was designed, consisting of three ASO pairs. The first and third pairs specifically amplify rop18 allele I and allele III, while the second pair amplify both allele I and II. Genomic DNA from 86 congenital infections was analyzed by ASO-PCRs, successfully typing 82 (95.35%) samples. The remaining 4 samples (4.65%) required sequencing and single nucleotide polymorphism (SNP) analysis of the amplification products. The distribution of samples according to rop18 alleles was: 39.5% of allele III, 38.4% of allele II, 19.8% of mixed rop18 alleles (I/III or II/III), and 2.3% of allele I. The six severely compromised infants exhibited the highest parasite load levels and were infected during the first and early second trimesters of pregnancy. Among these cases, two were associated with rop18 allele I parasites, two with mixed rop18 alleles (I/III), one with allele II, and one with allele III parasites. In conclusion, all severe cases of congenital toxoplasmosis were infected during early pregnancy, but they were not exclusively associated with rop18 allele I parasites, as observed in murine toxoplasmosis. Furthermore, nearly one-fifth of parasites were non-archetypal, exhibiting more than one rop18 allele, indicating a higher genetic diversity of Toxoplasma gondii in this South American sample. Overall, a robust T. gondii rop18 allele typing was developed and suggested that congenital toxoplasmosis in humans involves complex mechanisms beyond the parasite genotype.
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Affiliation(s)
- Emilly Henrique Dos Santos
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, Brasil; Departamento de Pediatria, Faculdade de Medicina, Universidade de São Paulo, Brasil
| | - Gabriel Acca Barreira
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, Brasil; Faculdade Israelita de Ciências da Saúde Albert Einstein (FICSAE), São Paulo, Brasil
| | - Lidia Yamamoto
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, Brasil
| | - Mussya Cisotto Rocha
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, Brasil
| | - Karen Alessandra Rodrigues
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, Brasil; Departamento de Pediatria, Faculdade de Medicina, Universidade de São Paulo, Brasil
| | | | | | - Thelma Suely Okay
- Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, Brasil; Departamento de Pediatria, Faculdade de Medicina, Universidade de São Paulo, Brasil.
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Barreira GA, Santos EHD, Pereira MFB, Rodrigues KA, Rocha MC, Kanunfre KA, Marques HHDS, Okay TS. Technical performance of a lateral flow immunoassay for detection of anti-SARS-CoV-2 IgG in the outpatient follow-up of non-severe cases and at different times after vaccination: comparison with enzyme and chemiluminescent immunoassays. Rev Inst Med Trop Sao Paulo 2022; 64:e49. [PMID: 35858039 PMCID: PMC9281580 DOI: 10.1590/s1678-9946202264049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/09/2022] [Indexed: 11/22/2022] Open
Abstract
This study assessed the technical performance of a rapid lateral flow immunochromatographic assay (LFIA) for the detection of anti-SARS-CoV-2 IgG and compared LFIA results with chemiluminescent immunoassay (CLIA) results and an in-house enzyme immunoassay (EIA). To this end, a total of 216 whole blood or serum samples from three groups were analyzed: the first group was composed of 68 true negative cases corresponding to blood bank donors, healthy young volunteers, and eight pediatric patients diagnosed with other coronavirus infections. The serum samples from these participants were obtained and stored in a pre-COVID-19 period, thus they were not expected to have COVID-19. In the second group of true positive cases, we chose to replace natural cases of COVID-19 by 96 participants who were expected to have produced anti-SARS-CoV-2 IgG antibodies 30-60 days after the vaccine booster dose. The serum samples were collected on the same day that LFIA were tested either by EIA or CLIA. The third study group was composed of 52 participants (12 adults and 40 children) who did or did not have anti-SARS-CoV-2 IgG antibodies due to specific clinical scenarios. The 12 adults had been vaccinated more than seven months before LFIA testing, and the 40 children had non-severe COVID-19 diagnosed using RT-PCR during the acute phase of infection. They were referred for outpatient follow-up and during this period the serum samples were collected and tested by CLIA and LFIA. All tests were performed by the same healthcare operator and there was no variation of LFIA results when tests were performed on finger prick whole blood or serum samples, so that results were grouped for analysis. LFIA's sensitivity in detecting anti-SARS-CoV-2 IgG antibodies was 90%, specificity 97.6%, efficiency 93%, PPV 98.3%, NPV 86.6%, and likelihood ratio for a positive or a negative result were 37.5 and 0.01 respectively. There was a good agreement (Kappa index of 0.677) between LFIA results and serological (EIA or CLIA) results. In conclusion, LFIA analyzed in this study showed a good technical performance and agreement with reference serological assays (EIA or CLIA), therefore it can be recommended for use in the outpatient follow-up of non-severe cases of COVID-19 and to assess anti-SARS-CoV-2 IgG antibody production induced by vaccination and the antibodies decrease over time. However, LFIAs should be confirmed by using reference serological assays whenever possible.
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Affiliation(s)
- Gabriel Acca Barreira
- Universidade de São Paulo, Faculdade de Medicina, Instituto de Medicina Tropical de São Paulo, São Paulo, São Paulo, Brazil.,Faculdade Israelita de Ciências da Saúde Albert Einstein, São Paulo, São Paulo, Brazil
| | - Emilly Henrique Dos Santos
- Universidade de São Paulo, Faculdade de Medicina, Instituto de Medicina Tropical de São Paulo, São Paulo, São Paulo, Brazil.,Universidade de São Paulo, Faculdade de Medicina, Departamento de Pediatria, São Paulo, São Paulo, Brazil
| | | | - Karen Alessandra Rodrigues
- Universidade de São Paulo, Faculdade de Medicina, Instituto de Medicina Tropical de São Paulo, São Paulo, São Paulo, Brazil
| | - Mussya Cisotto Rocha
- Universidade de São Paulo, Faculdade de Medicina, Instituto de Medicina Tropical de São Paulo, São Paulo, São Paulo, Brazil
| | - Kelly Aparecida Kanunfre
- Universidade de São Paulo, Faculdade de Medicina, Instituto de Medicina Tropical de São Paulo, São Paulo, São Paulo, Brazil
| | | | - Thelma Suely Okay
- Universidade de São Paulo, Faculdade de Medicina, Instituto de Medicina Tropical de São Paulo, São Paulo, São Paulo, Brazil.,Universidade de São Paulo, Faculdade de Medicina, Departamento de Pediatria, São Paulo, São Paulo, Brazil
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Domingues W, Dos Santos EH, Yamamoto L, Di Santi SM, Kanunfre KA, Okay TS. Single-round multiplex PCR with species-specific mitochondrial primers of P. falciparum, P. vivax/P. simium and P. malariae/P. brasilianum: Comparison with standard techniques. J Microbiol Methods 2021; 193:106398. [PMID: 34953974 DOI: 10.1016/j.mimet.2021.106398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 12/17/2021] [Accepted: 12/17/2021] [Indexed: 11/19/2022]
Abstract
A single-round multiplex PCR (mPCR) with species-specific primers (SSP) of three mitochondrial genes of Plasmodium, namely COX I, COX III and CYT B, was compared to microscopy and 18S rRNA semi-nested PCR, nested-PCR and Real Time PCRs (*PCRs). Each parasite has between 20 and 150 mitochondria and each mitochondria has one copy of each target gene, while 18S rRNA gene is repeated 4 to 8 times. The specificity of mPCR was assessed by testing Plasmodium from rodents and birds, parasites responsible for other endemic diseases in the country such as schistosomiasis, Chagas disease and leishmaniasis in addition to microorganisms that, like Plasmodium, can cause anemia (Bartonella henselae, Babesia vogeli, Rickettsia vini). No cross-reactions were detected. From a total of 149 specimens from suspected cases of malaria were tested, 97 were positive by microscopy (49 P. falciparum, 38 P. vivax, 6 P. malariae, 4 P. falciparum/P. vivax- mixed infections) and 52 were negative; 148 samples were positive by *PCRs (49 P. falciparum, 53 P. vivax, 7 P. malariae and 39 mixed infections) and one was negative; 146 were positive by mPCR (49 P. falciparum, 56 P. vivax, 9 P. malariae and 32 mixed infections) and three were negative. The comparison of groups found statistically significant differences between microscopy vs.*PCRs or vs. mPCR (p-values <0.0001), but no difference was found between mPCR vs. *PCRs (p=0.946). The agreement in the identification of Plasmodium species was only regular, with Kappa indices of 0.407 (microscopy vs. *PCRs), 0.433 (microscopy vs. mPCR) and 0.558 (*PCRs vs. mPCR). In conclusion, the diagnostic performance of mPCR was comparable to those of *PCRs, and superior to microscopy, although the identification of Plasmodium species showed many disagreements. In conclusion, a sensitive and specific one-round SSP multiplex PCR, capable of simultaneously detecting and identifying P. falciparum, P. vivax/P. simium and P. malariae/P. brasilianum may be useful in resource-constrained countries where quantitative amplifications are not yet fully accessible.
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Affiliation(s)
- Wilson Domingues
- Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Emilly Henrique Dos Santos
- Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Lidia Yamamoto
- Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Silvia Maria Di Santi
- Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil; Núcleo de Estudos em Malária, Superintendência de Controle de Endemias, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
| | - Kelly Aparecida Kanunfre
- Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil; LIM 48, Departamento de Moléstias Infecciosas e Parasitárias, Universidade de São Paulo, Faculdade de Medicina, São Paulo, São Paulo, Brazil
| | - Thelma Suely Okay
- Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil; Departamento de Pediatria, Faculdade de Medicina, Universidade de São Paulo, Brazil.
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de Paula CSY, Palandri GG, Fonseca TS, Vendramini TCA, Farhat SCL, Pereira MFB, Litvinov N, Toma RK, de Sá FVM, Rodrigues KR, Schvartsman C, Forsait S, Sakita NK, Kanunfre KA, Rocha MC, Dos Santos EH, Okay TS, Pinho JRR, de Carvalho WB, Carneiro-Sampaio M, Almeida Silva CA, Marques HHDS. Gastrointestinal manifestations are associated with severe pediatric COVID-19: A study in tertiary hospital. J Infect 2021; 83:e22-e25. [PMID: 33940088 PMCID: PMC8084879 DOI: 10.1016/j.jinf.2021.04.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 04/25/2021] [Indexed: 12/12/2022]
Affiliation(s)
| | | | - Taiane Siraisi Fonseca
- Instituto da Criança e do Adolescente (ICr), Hospital das Clínicas HCFMUSP, São Paulo, Brasil.
| | | | | | | | - Nadia Litvinov
- Instituto da Criança e do Adolescente (ICr), Hospital das Clínicas HCFMUSP, São Paulo, Brasil.
| | - Ricardo Katsuya Toma
- Instituto da Criança e do Adolescente (ICr), Hospital das Clínicas HCFMUSP, São Paulo, Brasil.
| | | | | | - Cláudio Schvartsman
- Instituto da Criança e do Adolescente (ICr), Hospital das Clínicas HCFMUSP, São Paulo, Brasil.
| | - Silvana Forsait
- Instituto de Tratamento do Câncer Infantil - ICr HCFMUSP, São Paulo, Brasil.
| | - Neusa Keico Sakita
- Instituto da Criança e do Adolescente (ICr), Hospital das Clínicas HCFMUSP, São Paulo, Brasil.
| | | | | | | | - Thelma Suely Okay
- Instituto de Medicina Tropical de São Paulo - USP, IMT-SP-USP, Brasil.
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Dos Santos EH, Yamamoto L, Domingues W, di Santi SM, Kanunfre KA, Okay TS. A new Real Time PCR with species-specific primers from Plasmodium malariae/P. brasilianum mitochondrial cytochrome b gene. Parasitol Int 2020; 76:102069. [PMID: 32032726 DOI: 10.1016/j.parint.2020.102069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/17/2020] [Accepted: 02/03/2020] [Indexed: 10/25/2022]
Abstract
Plasmodium malariae mainly causes asymptomatic submicroscopic parasitemia in the endemic Amazon and non-endemic Atlantic Forest, where the number of cases and transmission of malaria through blood transfusion has increased. This study developed a P. malariae/P. brasilianum Real Time PCR (rtPCR) targeting the cytochrome b oxidase (cytb), a highly repetitive gene (20-150 copies/parasite) that should detect more cases than the 18S rRNA (4-8 copies/parasite) gene-based amplification systems. Cytb from human and non-human Plasmodium species (including P. brasilianum) aligned to the only 20 African P. malariae cytb sequences identified polymorphic regions within which we designed P. malariae species-specific primers. Non-human Plasmodium species, related parasites, anemia-causing microorganisms, normal human DNA and 47 blood bank donors samples that were truly negative to malaria accessed rtPCR specificity. Truly positive samples (n = 101) with species identification by semi-nested, nested or TaqMan PCR, and four samples from the Atlantic Forest that were suspected of malaria but three of them had negative genus TaqMan and 18S rRNA nested PCR. The cloned amplification product used in standard curves determined qPCR detection limit (0.5-1 parasite equivalent/μL). The 10 positive P. malariae samples among truly positives yielded positive rtPCR results and more importantly, rtPCR detected the four samples suspected of malaria from the Atlantic Forest. The rtPCR specificity was 100%, reproducibility 11.1% and repeatability 6.7%. In conclusion, the proposed rtPCR is fast, apparently more sensitive than all 18S rRNA amplification systems for detecting extremely low parasitemia. The rtPCR is also specific to P. malariae/P. brasilianum species. This new molecular tool could be applied to the detection of P. malariae/brasilianum infections with submicroscopic parasitemias in the context of epidemiological studies and blood bank safety programs.
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Affiliation(s)
| | - Lidia Yamamoto
- Instituto de Medicina Tropical, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Wilson Domingues
- Instituto de Medicina Tropical, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Silvia Maria di Santi
- Instituto de Medicina Tropical, Universidade de São Paulo, São Paulo, SP, Brazil; Núcleo de Estudos em Malária, Superintendência de Controle de Endemias (SUCEN), São Paulo, SP, Brazil; Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Kelly Aparecida Kanunfre
- Instituto de Medicina Tropical, Universidade de São Paulo, São Paulo, SP, Brazil; LIM 48, Laboratório de Investigação Médica, Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Thelma Suely Okay
- Instituto de Medicina Tropical, Universidade de São Paulo, São Paulo, SP, Brazil; Departamento de Pediatria, Faculdade de Medicina, Universidade de São Paulo, SP, Brazil.
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