49 research outputs found
Molecular Characterization of the Porcine Group A Rotavirus NSP2 and NSP5/6 Genes from São Paulo State, Brazil, in 2011/12
Rotaviruses are responsible for the acute diarrhea in various mammalian and avian species. The nonstructural proteins NSP2 and NSP5 are involved in the rotavirus replication and the formation of viroplasm, cytoplasmic inclusion bodies within which new viral particles morphogenesis and viral RNA replication occur. There are few studies on the genetic diversity of those proteins; thus this study aims at characterizing the diversity of rotavirus based on NSP2 and NSP5 genes in rotaviruses circulating in Brazilian pig farms. For this purpose, 63 fecal samples from pig farms located in six different cities in the São Paulo State, Brazil, were screened by nested RT-PCR. Seven strains had the partial nucleotide sequencing for NSP2, whereas in six, the total sequencing for NSP5. All were characterized as genotype H1 and N1. The nucleotide identity of NSP2 genes ranged from 100% to 86.4% and the amino acid identity from 100% to 91.5%. For NSP5, the nucleotide identity was from 100% to 95.1% and the amino acid identity from 100% to 97.4%. It is concluded that the genotypes of the strains circulating in the region of study are in agreement with those reported in the literature for swine and that there is the possibility of interaction between human and animal rotaviruses
Diversity of porcine rotavirus genotypes in São Paulo State, Brazil
Rotavírus é uma das causas mais comuns de diarréia tanto em humanos quanto em diferentes espécies animais. Foi conduzido um estudo transversal a partir de 144 amostras fecais diarréicas colhidas de leitões, provenientes de 16 criações comerciais distribuídas por 10 municípios do Estado de São Paulo, Brasil, com o objetivo de se detectar a ocorrência de rotavírus e realizar sua caracterização molecular quanto seus genotipos G e P. Um total de 43 amostras (29,86%) foram positivas para rotavírus por Eletroforese em Gel de Poliacrilamida (PAGE) e ELISA, num esquema de triagem em paralelo. A caracterização mediante reações do tipo nested-multiplex RT-PCR demonstrou que, isoladamente, o genotipo P[6] foi o mais frequente, detectado em 25,58% das amostras, seguido pelo P[1] (11,63%) e P[7] (9,3%). Infecções concomitantes de genotipos P[6]+P[7] (9,3%), P[1]+P[6] (4,65%), P[1]+P[6]+P[7] (2,33%) foram também observadas. Analogamente, o genotipo G[5] foi detectado em 30,23% das amostras, seguido pelo G[10] (20,93%) e G[6] (4,65%) e G[5]+G[10] (18,6%). O genotipo G[5]P[6] foi o mais frequente (11,63%), porém outras combinações e amostras não tipificáveis também foram observadas. Considerando-se a diversidade de rotavírus suínos encontrada na população estudada, medidas profiláticas específicas devem levar em conta, para sua efetividade, o grau de proteção cruzada entre os genotipos presentes nas formulações vacinais e aqueles que realmente são circulantes numa região.Rotavirus is one the most common causes of diarrhea both in humans and different animal species. It was carried out a transversal study with 144 diarrheic fecal samples of piglets, from 16 commercial swine-producing units distributed among 10 municipalities of São Paulo State, Brazil, aiming at the detection of rotavirus occurrence and its molecular characterization according to G and P genotypes. A total of 43 samples (29.86%) were positive for rotavirus by Polyacrylamide Gel Electrophoresis (PAGE) and ELISA, in a parallel screening scheme. The nested-multiplex RT-PCR characterization revealed that, separately, the P[6] genotype was the most frequent, detected in 25.58% of the samples, followed by P[1] (11.63%) and P[7] (9.3%). Concomitant infection of the genotypes P[6]+P[7] (9.3%), P[1]+P[6] (4.65%), P[1]+P[6]+P[7] (2.33%) were also found. Similarly, the G[5] genotype was detected on 30.23% of the samples, followed by G[10] (20.93%), G[6] (4.65%) and G[5]+G[10] (18.6%). The genotype G[5]P[6] was the most frequent (11.63%), but other combinations and untypeable samples were also observed. Considering the diversity porcine rotavirus found in the surveyed population, specific prophylactic measures should take in charge, for its effectiveness, the cross-protection degree between the genotypes present on vaccine formulations and those that really circulates on a region.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Isolamento de rotavírus de cães assintomáticos no Brasil
Relata-se o isolamento de rotavírus, a partir de material fecal de dois cães assintomáticos, no Brasil. A ocorrência de rotavírus foi pesquisada em amostras fecais de nove cães assintomáticos, provenientes do Centro de Controle de Zoonoses do município de Osasco, SP. Duas das nove amostras analisadas, por eletroforese em gel de poliacrilamida, foram positivas. O isolamento de rotavírus foi realizado em linhagem de células MA-104, com adição de 10,0µg/mL de tripsina ao meio de manutenção, e confirmado pelo eletroferótipo característico de grupo
Soroprevalência de anticorpos anti-rotavírus do sorogrupo A em bovinos de uma fronteira pioneira na Amazônia brasileira
Rotavirus is a worldwide etiologic agent of diarrhea, responsible for large economic losses. We studied the seroprevalence of antibodies to group A rotavirus in cattle in 67 smallholder farms from Uruará municipality, using counterimmunoelectroosmophoresis with the NCDV strain as a standard antigen. Prevalence of positive smallholder farms was 95.6-100%. Significant differences were seen between age groups when the seropositivity rose from the youngest to the oldest groups and between females and males older than 1 year, when the seropositivity was higher in the first group.O rotavírus é um agente etiológico de diarréias de distribuição mundial, responsável por grandes prejuízos econômicos. Pesquisou-se a soroprevalência de anticorpos anti-rotavírus do sorogrupo A em bovinos criados no município de Uruará, utilizando a técnica da contraimunoeletroosmofore com a amostra NCDV como antígeno padrão. A prevalência de propriedades positivas foi de 95.6-100%. Diferenças significativas foram observadas entre as sucessivas faixas etárias, quando a soropositividade aumentou dos grupos mais jovens para os mais velhos, bem como entre fêmeas e machos maiores de 1 ano, quando a soropositividade foi maior no primeiro grupo
Comparative Susceptibility of Different Populations of Amblyomma sculptum to Rickettsia rickettsii
The bacterium Rickettsia rickettsii is the etiological agent of Brazilian spotted fever (BSF), which is transmitted in Brazil mainly by the tick Amblyomma sculptum. Herein, larvae and nymphs of six populations of A. sculptum were exposed to R. rickettsii by feeding on needle-inoculated guinea pigs, and thereafter reared on uninfected guinea pigs or rabbits. Two tick populations were exposed to autochthone R. rickettsii strains, whereas four tick populations were exposed to non-autochthone strains. The six geographically different populations of A. sculptum showed different susceptibilities to R. rickettsii, higher among the two tick populations that were exposed to their autochthone R. rickettsii strain. In addition, higher rates of transovarial transmission of R. rickettsii and vector competence success also included the two tick populations that were exposed to autochthone R. rickettsii strains. These results indicate that the susceptibility of A. sculptum to R. rickettsii varies among different tick populations, with a clear bias for higher susceptibility to an autochthone R. rickettsii strain that has already coevolved with a tick population for some time. Our results demonstrated that the R. rickettsii infection induces higher mortality of engorged larvae and nymphs, and tend to reduce the reproductive fitness of engorged females. All together, these results might explain the low R. rickettsii-infection rates of A. sculptum under natural conditions (usually <1%), and indicate that an A. sculptum population should not be able to sustain a R. rickettsii infection for successive tick generations without the creation of new cohorts of infected ticks via horizontal transmission on vertebrate rickettsemic hosts (amplifying hosts). Finally, despite of the ubiquitous distribution of A. sculptum in southeastern and central-western Brazil, most of the populations of this tick species are devoid of R. rickettsii infection. This scenario might be related to two major factors: (i) insufficient numbers of susceptible amplifying hosts; and (ii) lower susceptibilities of many tick populations. While the first factor has been demonstrated by mathematical models in previous studies, the second is highlighted by the results observed in the present study
Mycobacteria em queijos tipo Minas comercializados em feiras-livres de São Paulo, Brasil
Mycobacterium bovis is the causative agent of bovine tuberculosis, a disease that affects dairy herds throughout the Brazilian territory, constituting a neglected zoonosis transmitted by raw milk and its derivatives. In this study, we evaluated the presence of M. bovis and other mycobacteria in Minas cheese obtained from open fairs in the city of São Paulo between 2012 and 2013. Samples (n = 133) were decontaminated using hexa-cetylpyridinium chloride and seeded on Stonebrink–Leslie medium. The isolates were submitted to molecular identification by TB Multiplex PCR targeting the 16S rRNA gene and amplicon nucleotide sequencing. From 16 cheese samples (12%), we obtained 26 putative colonies of Mycobacterium spp., none of which belonged to any of the Mycobacterium tuberculosis, Mycobacterium avium, or Mycobacterium intracellulare complexes. Phylogenetic analysis showed that sample sequences were grouped in a clade that includes only non-tuberculous mycobacteria with proximity to sequences obtained from Mycobacterium novocastrense (3 sequences), Mycobacterium holsaticum (1 sequence), andMycobacterium elephantis (2 sequences). Although no epidemiological evidence was found regarding the importance of oral transmission of mycobacteria in healthy people, their importance in the immunosuppressed population remains uncertain.Mycobacterium bovis é o agente da tuberculose bovina, doença que acomete o rebanho em todo território brasileiro e é uma negligenciada zoonose transmitida pelo leite e seus derivados. Este trabalho avaliou a presença de M. bovis e outras micobactérias, em queijo minas meia-cura, obtidos em feiras-livres na cidade de São Paulo, entre os anos de 2012 e 2013. As amostras (n = 133) foram descontaminadas pelo método HPC (hexa-cetyl-pyridinium chloride) e semeadas em meio Stonebrink Leslie. Os isolados foram submetidos à identificação molecular por PCR TB multiplex, pesquisando-se o gene 16S rRNA, e ao sequenciamento nucleotídico. Dezesseis amostras (12%) possuiam 26 colônias sugestivas de Mycobacterium spp., mas nenhuma delas pertencia aos complexos Mycobacterium tuberculosis, Mycobacterium avium e Mycobacterium intracellulare. A análise filogenética mostrou que todas as amostras estavam agrupadas em clados que incluem apenas micobactérias não tuberculosas (MNT), sendo que algumas possuiam proximidade com sequências obtidas de Mycobacterium novocastrense (3 sequências), Mycobacterium hosaticum (1 sequência) e Mycobacterium elephantis (2 sequências). Embora no momento não haja evidência epidemiológica da importância da transmissão oral das micobactérias pra indivíduos saudáveis, sua importância na população imunossuprimida ainda é incerta
Molecular characterization of group A bovine rotavirus in southeastern and central-western Brazil, 2009-2010
Lidar Observations in South America. Part I - Mesosphere and Stratosphere
South America covers a large area of the globe and plays a fundamental function in its climate change, geographical features, and natural resources. However, it still is a developing area, and natural resource management and energy production are far from a sustainable framework, impacting the air quality of the area and needs much improvement in monitoring. There are significant activities regarding laser remote sensing of the atmosphere at different levels for different purposes. Among these activities, we can mention the mesospheric probing of sodium measurements and stratospheric monitoring of ozone, and the study of wind and gravity waves. Some of these activities are long-lasting and count on the support from the Latin American Lidar Network (LALINET). We intend to pinpoint the most significant scientific achievements and show the potential of carrying out remote sensing activities in the continent and show its correlations with other earth science connections and synergies. In Part I of this chapter, we will present an overview and significant results of lidar observations in the mesosphere and stratosphere. Part II will be dedicated to tropospheric observations
Lidar Observations in South America. Part II - Troposphere
In Part II of this chapter, we intend to show the significant advances and results concerning aerosols’ tropospheric monitoring in South America. The tropospheric lidar monitoring is also supported by the Latin American Lidar Network (LALINET). It is concerned about aerosols originating from urban pollution, biomass burning, desert dust, sea spray, and other primary sources. Cloud studies and their impact on radiative transfer using tropospheric lidar measurements are also presented