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Papers by Domingos da Silva Leite
Two hundred and five Escherichia coli strains isolated from calves with diarrhea from mid-western... more Two hundred and five Escherichia coli strains isolated from calves with diarrhea from mid-western Brazil were screened for the presence of virulence factors associated with bovine colibacillosis. One hundred and two (49.8%) of the E. coli strains produced toxins: Shiga toxins 1 (9.7%) and 2 (6.3%), a-hemolysin (9.7%), enterohemolysin(6.8%), Cytotoxic Necrotizing Factors type 1 (0.5%), and type 2 (4.4%), enterotoxins LT-II (8.3%) and STa (3.9%). No strain produced enterotoxin LT-I. Fimbrial adhesins F5 and F17 were produced by 7.3% and 4.8% of the strains, respectivly, and none expressed F41. Seven strains (3.4%) possessed the gene eae and belonged to serotypes O26:H-; O111:H- and O118:H16. These results suggest that calves in Brazil may be an important source of pathogenic E. coli for animals and humans.Duzentas e cinco amostras de Escherichia coli isoladas de bezerros com diarréia da região centro oeste do Brazil foram examinados quanto a presença de fatores de virulência associado...
Pesquisa Veterinaria Brasileira, 1990
Estudos das propriedades de virulencia de Escherichia coli associadas as infeccoes intestinais sa... more Estudos das propriedades de virulencia de Escherichia coli associadas as infeccoes intestinais sao importantes para compreender seus mecanismos diarreiogenicos. Em um trabalho anterior, realizado em nosso laboratorio descrevemos um fator de virulencia no sobrenadante de E. coli isoladas de agua de consumo na cidade de Ouro Preto, MG, com atividades enterotoxica e citotoxica. Este fator foi denominado enterotoxina termo-estavel ST-like (ST-L). A ST-L foi purificada a partir dos sobrenadantes de cultura de amostras de E.coli cultivadas em meio CAYE modificado, fracionado com sulfato de amonio e por ultrafiltracao e concentrado por liofilizacao. Este material foi submetido as cromatografias de exclusao molecular e fase reversa, em sistema HPLC. A ST-L purificada mostrou, pela analise eletroforetica em 2D, ponto isoeletrico (pI) em 6,19 e massa molecular de aproximadamente 2kDa. A atividade biologica pelos tratamentos com enzimas tripsina, proteinase K, ribonuclease ou pepsina. A citotoxicidade da ST-L manteve-se inalterada sob variacoes de pH (3 a 9) e tratamento com solventes orgânicos. A toxina resistiu ao aquecimento a 100oC mostrando ser termoestavel. A caracterizacao biologica da ST-L mostrou que varias linhagens celulares foram sensiveis aos seus efeitos citotoxicos, sofrendo alteracoes celulares e nucleares, em ate 24h, com a formacao de vacuolos citoplasmaticos e morte celular, conforme verificado pelos testes de viabilidade celular dos lisossomos, mitocondrias, membranas celulares e quantificacao da populacao celular das linhagens HEp-2, Vero, CaCo-2 e HT-29. A ST-L nao induziu acumulo de fluidos no teste de alca ligada em intestino de coelhos induzindo, contudo, acumulo de fluidos intestinais no teste de camundongos recem-nascidos (Dean). Foi possivel determinar que a toxina STL encontra-se codificada num plasmideo e apresenta uma regiao conservada de alta similaridade com estA2, o que justifica a presenca de efeito enterotoxico no teste de Dean. No entanto, nao foi possivel determinar a regiao ativa para a atividade citotoxica da ST-L. Em funcao das caracteristicas apresentadas sugere-se a toxina ST-L seja uma variante do grupo das enterotoxinas termoestaveis (ST) com atividade citotoxica produzida por E. coli diarreiogenicas Abstract
Scientific Reports, 2019
Bullfrog farming and trade practices are well-established, globally distributed, and economically... more Bullfrog farming and trade practices are well-established, globally distributed, and economically valuable, but pose risks for biodiversity conservation. Besides their negative impacts on native amphibian populations as an invasive species, bullfrogs play a key role in spreading the frog-killing fungus Batrachochytrium dendrobatidis (Bd) in the natural environment. Bullfrogs are tolerant to Bd, meaning that they can carry high infection loads without developing chytridiomycosis. To test the potential of bullfrog farms as reservoirs for diverse and virulent chytrid genotypes, we quantified Bd presence, prevalence and infection loads across approximately 1,500 farmed bullfrogs and in the water that is released from farms into the environment. We also described Bd genotypic diversity within frog farms by isolating Bd from dozens of infected tadpoles. We observed individuals infected with Bd in all sampled farms, with high prevalence (reaching 100%) and high infection loads (average 71,...
PeerJ, 2018
BackgroundUnderstanding of the physiological effects of chytridiomycosis is crucial to worldwide ... more BackgroundUnderstanding of the physiological effects of chytridiomycosis is crucial to worldwide amphibian conservation. Therefore, we analyzed the cardiac function of two anuran species (Xenopus laevisandPhysalaemus albonotatus) with different susceptibilities to infection by the causative agent of chytridiomycosis,Batrachochytrium dendrobatidis(hereafterBd).MethodsWe analyzed thein situheart rate (fH- bpm), relative ventricular mass (RVM -%), and Ca2+handling in heart ofBdinfected animals compared to uninfected controls of both study species.ResultsBdinfection resulted in a 78% decrease in contraction force values inP. albonotatuswhen compared to the less susceptibleX. laevis. This negative effect was even more evident (82%) for the cardiac pumping capacity. The time to reach peak tension was 125% longer inP. albonotatusthan inX. laevis, and cardiac relaxation was 57% longer.DiscussionThese results indicate a delay in the cardiac cycle ofP. albonotatuson a beat-to-beat basis, whic...
PLOS ONE, 2015
Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late ... more Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation.
North-Western Journal of Zoology, 2015
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa... more Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)112360362FAPESC - FUNDAÇÃO DE AMPARO A PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNQP - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [405285/2013-2]FAPESP [2011/51694-7]6949/2010-3405285/2013-22011/51694-7We are grateful for the collecting permit from Sistema de Autorização e Informação em Biodiversidade (SISBIOProc. no. 359871) and to Empresa de Pesquisa Agropecuária e Extensão Rural (EPAGRI) for providing meteorological data. The project was funded
Letters in Applied Microbiology
Adhesins (P-fimbriae, S-fimbriae, type 1 fimbriae and afimbrial adhesin), toxins (α-hemolysi... more Adhesins (P-fimbriae, S-fimbriae, type 1 fimbriae and afimbrial adhesin), toxins (α-hemolysin and cytotoxic necrotizing factor type 1), iron acquisition systems (aerobactin) and host defense avoidance mechanisms (capsule or lipopolysaccharide) have been shown to be prevalent in Escherichia coli strains associated with urinary tract infections. In this work, 162 Uropathogenic Escherichia coli (UPEC) strains from patients with cystitis were genotypically characterized by polymerase chain reaction (PCR) assay. We developed three multiplex PCR assays for virulence-related genes papC, papE/F, papG alleles, fimH, sfa/foc, afaE, hly, cnf-1, usp, cdtB, iucD, and kpsMTII, all of them previously identified in UPEC strains. The PCR assay results identified 158 fimH (97.5%), 86 kpsMTII (53.1%), 53 papC/papEF/papG (32.7%), 45 sfa (27.8%), 42 iucD (25.9%), 41 hly (25.3%), 36 usp (22.2%), 30 cnf-1(18.5%) and 10 afa (6.2%) strains. No strain was positive for cdtB. In this work, we also demonst...
Orientador : Domingos da Silva LeiteDissertação (mestrado) - Universidade Estadual de Campinas, I... more Orientador : Domingos da Silva LeiteDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaMestrad
Orientadores: Domingos da Silva Leite, Tomomasa YanoDissertação (mestrado) - Universidade Estadua... more Orientadores: Domingos da Silva Leite, Tomomasa YanoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaMestrad
Fibrose Cistica (FC) e uma doenca genetica, autossomica recessiva, caracterizada por anormalidade... more Fibrose Cistica (FC) e uma doenca genetica, autossomica recessiva, caracterizada por anormalidade no transporte eletrolitico. Pseudomonas aeruginosa e um importante patogeno oportunista, frequentemente encontrado em pacientes com FC. Nesses pacientes, a colonizacao inicial e feita com a bacteria na forma nao mucoide que, posteriormente, converte-se a forma mucoide. O objetivo desse trabalho foi verificar comparativamente a producao de alguns fatores de virulencia por P. aeruginosa em amostras mucoides e nao mucoides isoladas de pacientes com FC e em amostras isoladas de pacientes nao portadores de FC. O metodo para detectar hemolisina utilizou placas de agar sangue contendo 5% de sangue de carneiro. A hidrolise da gelatina foi utilizada para detectar a producao de gelatinase e a producao de elastase foi observada em placas contendo 1 % de elastina. A presenca de pili foi analisada pelo metodo de microhemaglutinacao e a capsula de alginato, pelo metodo de PCR para identificar os genes algD e algU. As linhagens nao mucoides isoladas de pacientes com FC e aquelas isoladas de outros casos clinicos produziram as exoenzimas gelatinas e e elastase em maior frequencia que as linhagens mucoides. A producao de hemolisina e a presenca dos genes algD e algU foi semelhante nos tres grupos bacterianos. O gene algD foi encontrado em todas as linhagens estudadas e o ensaio de microhemaglutinacao nao foi satisfatorio para detectar a presenca de pili em P. aeruginosa Abstract
This work evaluated the index of pathogenicity, the production of hemolysin and determination of ... more This work evaluated the index of pathogenicity, the production of hemolysin and determination of serogroups in Escherichia coli strains isolated from liver of commercial laying hens with one day of age. Thirtytwo lots were analyzed, of which 15 were positive for the isolation ofE. coli in the liver, for a total of 24 samples. The pathogenicity in one-day-old chicks was determined by inoculation in air sac and was classified as high, intermediate or low pathogenicity, or non-pathogenic. Serogroups were identified using a set of anti-O antisera (O1 to O180). The production of hemolysin was determined by plating on chicken blood agar (8%) and sheep blood agar (8%). Of the samples studied, 17 (70.83%) were classified as non-pathogenic, 6 (25%) as low pathogenicity and 1 (4.17%) as high pathogenicity. Fourteen different serogroups were identified: O1, O2, O5, O8, O15, O18, O22, O36, O64, O70, O75, O115, O132 and O141, while 5 samples were non-typable. Regarding the test for production of...
Escherichia coli tem sido isolada, com certa frequencia, apresentando antigenos flagelares (H) qu... more Escherichia coli tem sido isolada, com certa frequencia, apresentando antigenos flagelares (H) que nao sao reconhecidos por nenhum dos anti-soros disponibilizado pelo mais importante centro de referencia de E. coli, The International Escherichia and Klebsiella Centre (WHO) do Statens Serum Institut, Copenhague, Dinamarca. Atualmente sao reconhecidos 53 antigenos "H" e, nos ultimos 29 anos, nenhuma modificacao ocorreu na lista dos antigenos flagelares associados a Escherichia coli. Isto posto, os objetivos deste trabalho foram identificar os antigenos flagelares das cepas de E. coli que expressam H nao tipavel (HNT) e que apresentam fatores de virulencia associados a diferentes enteropatias. Esta identificacao foi realizada inicialmente, pela reacao em cadeia da polimerase (PCR) do gene fliC, responsavel pela proteina flagelina, das 53 amostras padroes para os antigenos H e das 20 amostras HNT (H nao-tipavel). Em seguida, os amplicons foram digeridos por enzimas de restricao e daquelas amostras que apresentaram perfis de restricoes distintos daqueles observados para as amostras padroes de antigeno H, foram produzidos soros em coelhos. Foram realizados testes de titulacao frente aos 53 antigenos padroes, frente ao antigeno homologo e frente aos antigenos das amostras HNT. As sequencia genicas das amostras HNT, obtidas na reacao de sequenciamento, foram comparadas aos diferentes genes de fliC armazenados no banco de dados do "National Center for Biotecnology Information" (NCBI) atraves do sistema BLAST, e o programa ClustalW foi utilizado para alinhamento das sequencias. Os resultados demonstraram que estas amostras apresentaram similaridade com antigenos padroes, entretanto, elas nao possuem a mesma sequencia nucleotidica e tambem nao reagiram fenotipicamente com o anti-soro esperado. Os dados obtidos permitem concluir que no conjunto de amostras estudado, treze amostras apresentaram antigeno flagelar diferente daqueles ja descritos na literatura, quando utilizado as tecnicas de PCR e/ou sorologia Abstract
The larval therapy involves the intentional applica tion of sterilized and alive dipterans larvae... more The larval therapy involves the intentional applica tion of sterilized and alive dipterans larvae on non - healing wounds with the purpose of cleaning out the necrotic tissue to facilitate the healing process. This study aimed to evaluate the sterilization proce ss and survival of Chrysomya megacephala (Fabricius), Chrysomya putoria (Wiedemann) and Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae) larvae, after treatment with sodium hypochlorite (NaClO). The experimental groups for each species were: control group (CG), in which it was used water; 0.5% sodium hypochlorite group (0.5% SHG); and 1% SHG. For testing the time for ea ch treatment, the eggs were washed for one or three minutes in the described solution. After, ali quots from the “rinsing water” were inoculated in Plate Count Agar (PCA) and blood agar (BA), with in cubation at 37oC and readings performed after 24 and 48 hours for both. For all species, there were no bacterial growth on PCA and BA regarding to bot...
Scientific Reports, 2020
In Brazil’s Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal ... more In Brazil’s Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to the rapid loss of amphibian populations here and worldwide. The impact of Bd on amphibians is determined by the host's immune system, of which the skin microbiome is a critical component. The richness and diversity of such cutaneous bacterial communities are known to be shaped by abiotic factors which thus may indirectly modulate host susceptibility to Bd. This study aimed to contribute to understanding the environment-host–pathogen interaction determining skin bacterial communities in 819 treefrogs (Anura: Hylidae and Phyllomedusidae) from 71 species sampled across the AF. We investigated whether abiotic factors influence the bacterial community richness and structure on the amphibian skin. We further tested for an association between skin bacterial community structure and Bd co-occurrence. Our data revealed that temperature, p...
Embora as moscas sejam conhecidas como vetores de varios patogenos, poucos trabalhos discutem a p... more Embora as moscas sejam conhecidas como vetores de varios patogenos, poucos trabalhos discutem a participacao desses dipteros na transmissao de VTEC no ambiente. Considerando que o principal reservatorio de VTEC e o gado saudavel, este estudo buscou verificar a presenca de tais cepas em dipteros muscoides e bovinos com aptidao leiteira. Cepas de Escherichia coli foram isoladas da superficie externa de moscas coletadas no ambiente de ordenha e das fezes de bezerros e vacas, aparentemente saudaveis, de uma propriedade leiteira da regiao de Botucatu, SP. A presenca de Verotoxina foi investigada por PCR para os genes stx1 e stx2 e ensaio in vitro de citotoxicidade em celulas Vero. As analises estatisticas foram realizadas utilizando o teste exato de Fisher. De 57 moscas foram isoladas 135 cepas de E. coli sendo que 7/135 (5,2%) apresentaram genotipo positivo apenas para stx1 . Das 286 cepas isoladas de 58 bezerros, 84/286 (29,4%) foram positivas para stx1 , 12/286 (4,2%) para stx2 e 3/28...
Two hundred and five Escherichia coli strains isolated from calves with diarrhea from mid-western... more Two hundred and five Escherichia coli strains isolated from calves with diarrhea from mid-western Brazil were screened for the presence of virulence factors associated with bovine colibacillosis. One hundred and two (49.8%) of the E. coli strains produced toxins: Shiga toxins 1 (9.7%) and 2 (6.3%), a-hemolysin (9.7%), enterohemolysin(6.8%), Cytotoxic Necrotizing Factors type 1 (0.5%), and type 2 (4.4%), enterotoxins LT-II (8.3%) and STa (3.9%). No strain produced enterotoxin LT-I. Fimbrial adhesins F5 and F17 were produced by 7.3% and 4.8% of the strains, respectivly, and none expressed F41. Seven strains (3.4%) possessed the gene eae and belonged to serotypes O26:H-; O111:H- and O118:H16. These results suggest that calves in Brazil may be an important source of pathogenic E. coli for animals and humans.Duzentas e cinco amostras de Escherichia coli isoladas de bezerros com diarréia da região centro oeste do Brazil foram examinados quanto a presença de fatores de virulência associado...
Pesquisa Veterinaria Brasileira, 1990
Estudos das propriedades de virulencia de Escherichia coli associadas as infeccoes intestinais sa... more Estudos das propriedades de virulencia de Escherichia coli associadas as infeccoes intestinais sao importantes para compreender seus mecanismos diarreiogenicos. Em um trabalho anterior, realizado em nosso laboratorio descrevemos um fator de virulencia no sobrenadante de E. coli isoladas de agua de consumo na cidade de Ouro Preto, MG, com atividades enterotoxica e citotoxica. Este fator foi denominado enterotoxina termo-estavel ST-like (ST-L). A ST-L foi purificada a partir dos sobrenadantes de cultura de amostras de E.coli cultivadas em meio CAYE modificado, fracionado com sulfato de amonio e por ultrafiltracao e concentrado por liofilizacao. Este material foi submetido as cromatografias de exclusao molecular e fase reversa, em sistema HPLC. A ST-L purificada mostrou, pela analise eletroforetica em 2D, ponto isoeletrico (pI) em 6,19 e massa molecular de aproximadamente 2kDa. A atividade biologica pelos tratamentos com enzimas tripsina, proteinase K, ribonuclease ou pepsina. A citotoxicidade da ST-L manteve-se inalterada sob variacoes de pH (3 a 9) e tratamento com solventes orgânicos. A toxina resistiu ao aquecimento a 100oC mostrando ser termoestavel. A caracterizacao biologica da ST-L mostrou que varias linhagens celulares foram sensiveis aos seus efeitos citotoxicos, sofrendo alteracoes celulares e nucleares, em ate 24h, com a formacao de vacuolos citoplasmaticos e morte celular, conforme verificado pelos testes de viabilidade celular dos lisossomos, mitocondrias, membranas celulares e quantificacao da populacao celular das linhagens HEp-2, Vero, CaCo-2 e HT-29. A ST-L nao induziu acumulo de fluidos no teste de alca ligada em intestino de coelhos induzindo, contudo, acumulo de fluidos intestinais no teste de camundongos recem-nascidos (Dean). Foi possivel determinar que a toxina STL encontra-se codificada num plasmideo e apresenta uma regiao conservada de alta similaridade com estA2, o que justifica a presenca de efeito enterotoxico no teste de Dean. No entanto, nao foi possivel determinar a regiao ativa para a atividade citotoxica da ST-L. Em funcao das caracteristicas apresentadas sugere-se a toxina ST-L seja uma variante do grupo das enterotoxinas termoestaveis (ST) com atividade citotoxica produzida por E. coli diarreiogenicas Abstract
Scientific Reports, 2019
Bullfrog farming and trade practices are well-established, globally distributed, and economically... more Bullfrog farming and trade practices are well-established, globally distributed, and economically valuable, but pose risks for biodiversity conservation. Besides their negative impacts on native amphibian populations as an invasive species, bullfrogs play a key role in spreading the frog-killing fungus Batrachochytrium dendrobatidis (Bd) in the natural environment. Bullfrogs are tolerant to Bd, meaning that they can carry high infection loads without developing chytridiomycosis. To test the potential of bullfrog farms as reservoirs for diverse and virulent chytrid genotypes, we quantified Bd presence, prevalence and infection loads across approximately 1,500 farmed bullfrogs and in the water that is released from farms into the environment. We also described Bd genotypic diversity within frog farms by isolating Bd from dozens of infected tadpoles. We observed individuals infected with Bd in all sampled farms, with high prevalence (reaching 100%) and high infection loads (average 71,...
PeerJ, 2018
BackgroundUnderstanding of the physiological effects of chytridiomycosis is crucial to worldwide ... more BackgroundUnderstanding of the physiological effects of chytridiomycosis is crucial to worldwide amphibian conservation. Therefore, we analyzed the cardiac function of two anuran species (Xenopus laevisandPhysalaemus albonotatus) with different susceptibilities to infection by the causative agent of chytridiomycosis,Batrachochytrium dendrobatidis(hereafterBd).MethodsWe analyzed thein situheart rate (fH- bpm), relative ventricular mass (RVM -%), and Ca2+handling in heart ofBdinfected animals compared to uninfected controls of both study species.ResultsBdinfection resulted in a 78% decrease in contraction force values inP. albonotatuswhen compared to the less susceptibleX. laevis. This negative effect was even more evident (82%) for the cardiac pumping capacity. The time to reach peak tension was 125% longer inP. albonotatusthan inX. laevis, and cardiac relaxation was 57% longer.DiscussionThese results indicate a delay in the cardiac cycle ofP. albonotatuson a beat-to-beat basis, whic...
PLOS ONE, 2015
Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late ... more Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation.
North-Western Journal of Zoology, 2015
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa... more Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)112360362FAPESC - FUNDAÇÃO DE AMPARO A PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNQP - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [405285/2013-2]FAPESP [2011/51694-7]6949/2010-3405285/2013-22011/51694-7We are grateful for the collecting permit from Sistema de Autorização e Informação em Biodiversidade (SISBIOProc. no. 359871) and to Empresa de Pesquisa Agropecuária e Extensão Rural (EPAGRI) for providing meteorological data. The project was funded
Letters in Applied Microbiology
Adhesins (P-fimbriae, S-fimbriae, type 1 fimbriae and afimbrial adhesin), toxins (α-hemolysi... more Adhesins (P-fimbriae, S-fimbriae, type 1 fimbriae and afimbrial adhesin), toxins (α-hemolysin and cytotoxic necrotizing factor type 1), iron acquisition systems (aerobactin) and host defense avoidance mechanisms (capsule or lipopolysaccharide) have been shown to be prevalent in Escherichia coli strains associated with urinary tract infections. In this work, 162 Uropathogenic Escherichia coli (UPEC) strains from patients with cystitis were genotypically characterized by polymerase chain reaction (PCR) assay. We developed three multiplex PCR assays for virulence-related genes papC, papE/F, papG alleles, fimH, sfa/foc, afaE, hly, cnf-1, usp, cdtB, iucD, and kpsMTII, all of them previously identified in UPEC strains. The PCR assay results identified 158 fimH (97.5%), 86 kpsMTII (53.1%), 53 papC/papEF/papG (32.7%), 45 sfa (27.8%), 42 iucD (25.9%), 41 hly (25.3%), 36 usp (22.2%), 30 cnf-1(18.5%) and 10 afa (6.2%) strains. No strain was positive for cdtB. In this work, we also demonst...
Orientador : Domingos da Silva LeiteDissertação (mestrado) - Universidade Estadual de Campinas, I... more Orientador : Domingos da Silva LeiteDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaMestrad
Orientadores: Domingos da Silva Leite, Tomomasa YanoDissertação (mestrado) - Universidade Estadua... more Orientadores: Domingos da Silva Leite, Tomomasa YanoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaMestrad
Fibrose Cistica (FC) e uma doenca genetica, autossomica recessiva, caracterizada por anormalidade... more Fibrose Cistica (FC) e uma doenca genetica, autossomica recessiva, caracterizada por anormalidade no transporte eletrolitico. Pseudomonas aeruginosa e um importante patogeno oportunista, frequentemente encontrado em pacientes com FC. Nesses pacientes, a colonizacao inicial e feita com a bacteria na forma nao mucoide que, posteriormente, converte-se a forma mucoide. O objetivo desse trabalho foi verificar comparativamente a producao de alguns fatores de virulencia por P. aeruginosa em amostras mucoides e nao mucoides isoladas de pacientes com FC e em amostras isoladas de pacientes nao portadores de FC. O metodo para detectar hemolisina utilizou placas de agar sangue contendo 5% de sangue de carneiro. A hidrolise da gelatina foi utilizada para detectar a producao de gelatinase e a producao de elastase foi observada em placas contendo 1 % de elastina. A presenca de pili foi analisada pelo metodo de microhemaglutinacao e a capsula de alginato, pelo metodo de PCR para identificar os genes algD e algU. As linhagens nao mucoides isoladas de pacientes com FC e aquelas isoladas de outros casos clinicos produziram as exoenzimas gelatinas e e elastase em maior frequencia que as linhagens mucoides. A producao de hemolisina e a presenca dos genes algD e algU foi semelhante nos tres grupos bacterianos. O gene algD foi encontrado em todas as linhagens estudadas e o ensaio de microhemaglutinacao nao foi satisfatorio para detectar a presenca de pili em P. aeruginosa Abstract
This work evaluated the index of pathogenicity, the production of hemolysin and determination of ... more This work evaluated the index of pathogenicity, the production of hemolysin and determination of serogroups in Escherichia coli strains isolated from liver of commercial laying hens with one day of age. Thirtytwo lots were analyzed, of which 15 were positive for the isolation ofE. coli in the liver, for a total of 24 samples. The pathogenicity in one-day-old chicks was determined by inoculation in air sac and was classified as high, intermediate or low pathogenicity, or non-pathogenic. Serogroups were identified using a set of anti-O antisera (O1 to O180). The production of hemolysin was determined by plating on chicken blood agar (8%) and sheep blood agar (8%). Of the samples studied, 17 (70.83%) were classified as non-pathogenic, 6 (25%) as low pathogenicity and 1 (4.17%) as high pathogenicity. Fourteen different serogroups were identified: O1, O2, O5, O8, O15, O18, O22, O36, O64, O70, O75, O115, O132 and O141, while 5 samples were non-typable. Regarding the test for production of...
Escherichia coli tem sido isolada, com certa frequencia, apresentando antigenos flagelares (H) qu... more Escherichia coli tem sido isolada, com certa frequencia, apresentando antigenos flagelares (H) que nao sao reconhecidos por nenhum dos anti-soros disponibilizado pelo mais importante centro de referencia de E. coli, The International Escherichia and Klebsiella Centre (WHO) do Statens Serum Institut, Copenhague, Dinamarca. Atualmente sao reconhecidos 53 antigenos "H" e, nos ultimos 29 anos, nenhuma modificacao ocorreu na lista dos antigenos flagelares associados a Escherichia coli. Isto posto, os objetivos deste trabalho foram identificar os antigenos flagelares das cepas de E. coli que expressam H nao tipavel (HNT) e que apresentam fatores de virulencia associados a diferentes enteropatias. Esta identificacao foi realizada inicialmente, pela reacao em cadeia da polimerase (PCR) do gene fliC, responsavel pela proteina flagelina, das 53 amostras padroes para os antigenos H e das 20 amostras HNT (H nao-tipavel). Em seguida, os amplicons foram digeridos por enzimas de restricao e daquelas amostras que apresentaram perfis de restricoes distintos daqueles observados para as amostras padroes de antigeno H, foram produzidos soros em coelhos. Foram realizados testes de titulacao frente aos 53 antigenos padroes, frente ao antigeno homologo e frente aos antigenos das amostras HNT. As sequencia genicas das amostras HNT, obtidas na reacao de sequenciamento, foram comparadas aos diferentes genes de fliC armazenados no banco de dados do "National Center for Biotecnology Information" (NCBI) atraves do sistema BLAST, e o programa ClustalW foi utilizado para alinhamento das sequencias. Os resultados demonstraram que estas amostras apresentaram similaridade com antigenos padroes, entretanto, elas nao possuem a mesma sequencia nucleotidica e tambem nao reagiram fenotipicamente com o anti-soro esperado. Os dados obtidos permitem concluir que no conjunto de amostras estudado, treze amostras apresentaram antigeno flagelar diferente daqueles ja descritos na literatura, quando utilizado as tecnicas de PCR e/ou sorologia Abstract
The larval therapy involves the intentional applica tion of sterilized and alive dipterans larvae... more The larval therapy involves the intentional applica tion of sterilized and alive dipterans larvae on non - healing wounds with the purpose of cleaning out the necrotic tissue to facilitate the healing process. This study aimed to evaluate the sterilization proce ss and survival of Chrysomya megacephala (Fabricius), Chrysomya putoria (Wiedemann) and Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae) larvae, after treatment with sodium hypochlorite (NaClO). The experimental groups for each species were: control group (CG), in which it was used water; 0.5% sodium hypochlorite group (0.5% SHG); and 1% SHG. For testing the time for ea ch treatment, the eggs were washed for one or three minutes in the described solution. After, ali quots from the “rinsing water” were inoculated in Plate Count Agar (PCA) and blood agar (BA), with in cubation at 37oC and readings performed after 24 and 48 hours for both. For all species, there were no bacterial growth on PCA and BA regarding to bot...
Scientific Reports, 2020
In Brazil’s Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal ... more In Brazil’s Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to the rapid loss of amphibian populations here and worldwide. The impact of Bd on amphibians is determined by the host's immune system, of which the skin microbiome is a critical component. The richness and diversity of such cutaneous bacterial communities are known to be shaped by abiotic factors which thus may indirectly modulate host susceptibility to Bd. This study aimed to contribute to understanding the environment-host–pathogen interaction determining skin bacterial communities in 819 treefrogs (Anura: Hylidae and Phyllomedusidae) from 71 species sampled across the AF. We investigated whether abiotic factors influence the bacterial community richness and structure on the amphibian skin. We further tested for an association between skin bacterial community structure and Bd co-occurrence. Our data revealed that temperature, p...
Embora as moscas sejam conhecidas como vetores de varios patogenos, poucos trabalhos discutem a p... more Embora as moscas sejam conhecidas como vetores de varios patogenos, poucos trabalhos discutem a participacao desses dipteros na transmissao de VTEC no ambiente. Considerando que o principal reservatorio de VTEC e o gado saudavel, este estudo buscou verificar a presenca de tais cepas em dipteros muscoides e bovinos com aptidao leiteira. Cepas de Escherichia coli foram isoladas da superficie externa de moscas coletadas no ambiente de ordenha e das fezes de bezerros e vacas, aparentemente saudaveis, de uma propriedade leiteira da regiao de Botucatu, SP. A presenca de Verotoxina foi investigada por PCR para os genes stx1 e stx2 e ensaio in vitro de citotoxicidade em celulas Vero. As analises estatisticas foram realizadas utilizando o teste exato de Fisher. De 57 moscas foram isoladas 135 cepas de E. coli sendo que 7/135 (5,2%) apresentaram genotipo positivo apenas para stx1 . Das 286 cepas isoladas de 58 bezerros, 84/286 (29,4%) foram positivas para stx1 , 12/286 (4,2%) para stx2 e 3/28...