Comparação dos diagnósticos sorológico e molecular da leptospirose humana na região metropolitana de Curitiba, Paraná

Orientadora : Prof. Dr. Alexander Welker BiondoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e Molecular. Defesa: Curitiba, 2007Inclui bibliografiaA leptospirose é uma zoonose de distribuição mundial que apresenta sintomas clínicos não-específicos, cujo diagnóstico definitivo depende de testes laboratoriais. Amostras de sangue total, plasma e soro contaminadas in vitro foram submetidas à PCR em sistemas monoplex e duplex, utilizando dois conjuntos de iniciadores previamente descritos (G1/G2 e A/B). Posteriormente, amostras clínicas de sangue e urina foram amplificadas com os mesmos iniciadores para o diagnóstico da leptospirose. Amplificações com os iniciadores G1/G2 apresentaram sensibilidade de 60,7% e especificidade de 65,8%, contra 7,1% e 94,7% obtidas com os iniciadores A/B. Sensibilidade e especificidade gerais da PCR foram 53,6% e 63,2%, respectivamente. Sessenta e seis amostras clínicas foram testadas por ELISA IgM, MAT e PCR de sangue e urina, acompanhadas de 15 amostras pareadas. A detecção do DNA das leptospiras por PCR ocorreu a partir do primeiro dia de doença, enquanto a detecção dos anticorpos pelo MAT só foi possível a partir do quinto dia. Nossos resultados sugerem que amostras de sangue são mais apropriadas para a investigação clínica da leptospiremia, frente a amostras de plasma ou soro. Essas amostras apresentaram limite mínimo de detecção de 5x10³, 5x10 elevado a 4 e 5x10 elevado a 6 células/ml, respectivamente. Apesar da amplificação parcial do gene secY ser utilizada para a detecção de leptospiras patogênicas, o seqüenciamento desses produtos de PCR não permitiu a genotipagem da cepa infectante. A PCR foi menos sensível (53,6%) do que o ELISA IgM (85,7%) ao longo do curso da doença. Entretanto, a PCR realizada em amostras de sangue ou urina permitiu o diagnóstico precoce em 71,4% dos pacientes cuja soroconversão foi confirmada pelo MAT. Assim, a PCR constitui uma ferramenta complementar na primeira fase da doença, especialmente quando não é possível detectar anticorpos específicos pelas técnicas sorológicas, permitindo a confirmação precoce da infecção e o diagnóstico diferencial de outras doenças febris.Leptospirosis is a worldwide zoonosis of nonspecific clinical symptoms, which definitive diagnosis relies on laboratorial tests. Whole blood, plasma and serum samples in vitro contaminated were submitted to both monoplex and duplex PCR assays using previously described protocols (G1/G2 and A/B). Next, whole blood and urine clinical specimens were amplified with the same primers for diagnosis of leptospirosis. G1/G2-primed amplifications showed sensitivity of 60.7% and specificity of 65.8%, compared to 7.1% and 94.7% of the A/B-primed reactions. Overall PCR sensitivity and specificity was 53.6% and 63.2%, respectively. Sixty-six clinical samples tested by IgM ELISA, MAT and blood and urine PCR, along with 15 paired samples. PCR detection of leptospiral DNA occurred from the first day of illness, while antibodies detection by MAT was possible from the fifth day. Our results suggest that whole blood specimens are more appropriate for clinical investigation of leptospiremia, when compared to plasma or serum samples. Those samples had minimal detection limit of 5x10³, 5x10 to the power of 4 e 5x10 to the power of 6 cells/ml, respectively. Although PCR of secY gene fragment has been used for diagnosis of pathogenic leptospires, sequencing of respective amplicons does not allow genotyping of the infecting strain. PCR was less sensitive (53.6%) than IgM ELISA (85.7%) throughout the course of the disease. However, PCR performed on blood or urine samples permitted early diagnosis in 71.4% of patients whose seroconversion was confirmed by MAT. Thus, PCR constitutes a complementary tool in the first phase of the illness, especially when no specific antibodies can be detected by serological techniques, allowing early confirmation of the infection and differential diagnosis from other infectious febrile diseases

Whole-Genome Characterization of a Novel Human Influenza A(H1N2) Virus Variant, Brazil

We report the characterization of a novel reassortant influenza A(H1N2) virus not previously reported in humans. Recovered from a a pig farm worker in southeast Brazil who had influenza-like illness, this virus is a triple reassortant containing gene segments from subtypes H1N2 (hemagglutinin), H3N2 (neuraminidase), and pandemic H1N1 (remaining genes)

Molecular identification and typing of Mycobacterium massiliense isolated from postsurgical infections in Brazil

AbstractObjectiveOne hundred thirty-one cases of postsurgical infections were reported in Southern Region of Brazil between August 2007 and January 2008. Thirty-nine (29.8%) cases were studied; this report describes epidemiological findings, species identification, antimicrobial susceptibility and clonal diversity of rapidly growing mycobacteria isolated in this outbreak.MethodsAll 39 isolates were analyzed by Ziehl-Nielsen stained smear, bacterial culture and submitted to rpoB partial gene sequencing for identification. The isolates were also evaluated for their susceptibility to amikacin, cefoxitin, clarithromycin, ciprofloxacin, doxycycline, tobramycin and sulfamethoxazole.ResultsThirty-six isolates out of the confirmed cases were identified as Mycobacterium massiliense and the remaining three were identified as Mycobacterium abscessus, Mycobacterium chelonae and Mycobacterium fortuitum. All M. massiliense isolates were susceptible to amikacin (MIC90=8μg/mL) and clarithromycin (MIC90=0.25μg/mL) but resistant to cefoxitin, ciprofloxacin, doxycycline, tobramycin and sulfamethoxazole. Molecular analysis by pulsed-field gel electrophoresis clustered all 36 M. massiliense isolates and showed the same pattern (BRA 100) observed in three other outbreaks previously reported in Brazil.ConclusionsThese findings suggest a common source of infection for all patients and reinforce the hypotheses of spread of M. massiliense BRA100 in Brazilian hospital surgical environment in recent years

Identification of a novel alphavirus related to the encephalitis complexes circulating in southern Brazil

Submitted by Manoel Barata ([email protected]) on 2019-07-22T17:44:10Z No. of bitstreams: 1 222217512019.pdf: 4079083 bytes, checksum: 65970f6566a9f9aee02974252f0933b3 (MD5)Approved for entry into archive by Manoel Barata ([email protected]) on 2019-07-22T18:15:37Z (GMT) No. of bitstreams: 1 222217512019.pdf: 4079083 bytes, checksum: 65970f6566a9f9aee02974252f0933b3 (MD5)Made available in DSpace on 2019-07-22T18:15:37Z (GMT). No. of bitstreams: 1 222217512019.pdf: 4079083 bytes, checksum: 65970f6566a9f9aee02974252f0933b3 (MD5) Previous issue date: 2019Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Virologia Molecular. Curitiba, PR, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Virologia Molecular. Curitiba, PR, Brasil.Universidade Federal do Rio de Janeiro. Departamento de Genética. Instituto de Biologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Virologia Molecular. Curitiba, PR, Brasil.Secretaria da Saúde do Estado do Paraná. Laboratório Central. São José dos Pinhais, PR, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Regulação da Expressão Gênica. Curitiba, PR, Brasil.Secretaria da Saúde do Estado do Paraná. Laboratório Central. São José dos Pinhais, PR, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Biologia Celular. Curitiba, PR, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Virologia Molecular. Curitiba, PR, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Virologia Molecular. Curitiba, PR, Brasil.Fundação Oswaldo Cruz. Instituto Carlos Chagas. Laboratório de Virologia Molecular. Curitiba, PR, Brasil.In early 2017, an outbreak caused by an unknown and supposedly viral agent in the Marilena region of southern Brazil was investigated. Since the etiological agent causing the outbreak was not identified from human samples, mosquitoes from this region were collected. Three out of 121 mosquito pools collected from the region tested positive for alphavirus in molecular tests. Next generation sequencing results revealed the presence of a novel alphavirus, tentatively named here as Caainguá virus (CAAV). DNA barcoding analyses indicated that different species of Culex are hosts for CAAV. This new virus was basal to the New World encephalitic alphaviruses in a comprehensive and robust phylogenetic approach using complete genomes. Viral particles were observed in the cytosol and inside of intracellular compartments of cells in mosquito-derived cell cultures. Despite being noninfectious in vertebrate derived cell cultures, primary culturing of CAAV in human mononuclear cells suggests monocytes and lymphocytes as CAAV targets. However, the epidemiological link of CAAV on the human outbreak should be further explored

Reemergence of Dengue Virus Serotype 3, Brazil, 2023

We characterized 3 autochthonous dengue virus serotype 3 cases and 1 imported case from 2 states in the North and South Regions of Brazil, 15 years after Brazil's last outbreak involving this serotype. We also identified a new Asian lineage recently introduced into the Americas, raising concerns about future outbreaks

Genomic epidemiology reveals how restriction measures shaped the SARS-CoV-2 epidemic in Brazil

Abstract Brazil has experienced some of the highest numbers of COVID-19 infections and deaths globally and made Latin America a pandemic epicenter from May 2021. Although SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, important gaps remain in our understanding of local virus transmission dynamics. Here, we describe the genomic epidemiology of SARS-CoV-2 using near-full genomes sampled from 27 Brazilian states and an adjacent country - Paraguay. We show that the early stage of the pandemic in Brazil was characterised by the co-circulation of multiple viral lineages, linked to multiple importations predominantly from Europe, and subsequently characterized by large local transmission clusters. As the epidemic progressed, the absence of effective restriction measures led to the local emergence and international spread of Variants of Concern (VOC) and under monitoring (VUM), including the Gamma (P.1) and Zeta (P.2) variants. In addition, we provide a preliminary genomic overview of the epidemic in Paraguay, showing evidence of importation from Brazil. These data reinforce the need for the implementation of widespread genomic surveillance in South America as a toolkit for pandemic monitoring and providing a means to follow the real-time spread of emerging SARS-CoV-2 variants with possible implications for public health and immunization strategies