Marcia Kober - Academia.edu (original) (raw)

Papers by Marcia Kober

Research paper thumbnail of Differentiation ofSalmonellaEnteritidis Isolates by Fluorescent Amplified Fragment Length Polymorphism

Foodborne Pathogens and Disease, 2011

Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the mole... more Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the molecular characterization of isolates is an important tool for epidemiological studies. Fluorescent amplified fragment length polymorphism (FAFLP) analysis was performed on 31 Salmonella Enteritidis strains from South Brazil isolated from human, foods, swine, broiler carcasses, and other poultry-related samples to subtype isolates in comparison to pulsed-field gel electrophoresis (PFGE) analysis. Five strains of Salmonella Enteritidis from different geographical regions, Salmonella Enteritidis ATCC 13076, and four isolates of different Salmonella serovars were also tested. Among the 41 isolates tested, 96 polymorphic AFs and 40 distinct profiles were obtained, displaying a Simpson's index of diversity of 0.99; whereas the PFGE analysis presented 13 patterns and the resulting Simpson's index was 0.55. Nine FAFLP and seven PFGE clusters could be inferred based in Dice similarity coefficient. FAFLP clustering readily identified different serotypes of Salmonella but did not distinguish isolates epidemiologically nonrelated or distinct phage types. Therefore, these results indicate that FAFLP is a rapid method for epidemiological investigations of Salmonella outbreaks, presenting a high discriminatory power for subtyping of Salmonella Enteritidis.

Research paper thumbnail of Avaliação da competitividade, entre isolados de Bradyrhizobiumjaponicum, e expressão da fixação simbiótica em soja

Research paper thumbnail of Serology for toxoplaSmoSiS in pregnant women and newbornS from Santo antônio da patrulha, rio grande do Sul, brazil

Introduction: Serological tests have been used to detect the presence of possible etiologic agent... more Introduction: Serological tests have been used to detect the presence of possible etiologic agents during pregnancy. This study aimed to evaluate the serological profile of toxoplasmosis in pregnant women and newborns and to correlate women’s age group with seroprevalence.

Research paper thumbnail of Diversidade genética de isolados de Salmonella Enteritidis avaliada por FAFLP (Análise de fragmentos polimórficos amplificados e fluorescentes) e MLST (Tipificação por sequenciamento de múltiplos loci)

Salmonella Enteritidis is a common foodborne pathogen that causes gastroenteritis and systemic in... more Salmonella Enteritidis is a common foodborne pathogen that causes gastroenteritis and systemic infections in humans. The characterization of this bacterium is essential for epidemiological studies. In this context, two molecular methods, MLST and FAFLP, were tested for characterization of 32 S. Enteritidis isolates obtained from South of Brazil, as well as five isolates obtained from other geographical areas. Four isolates of different serovars of Salmonella (S. Panama, S. Senftenberg, S. Typhimurium and Salmonella [4,5:-:1,2]) were included as outgroup. These two techniques were already used to analyze different Salmonella serovars, but this study is the first to use them to discriminate the same S. Enteritidis isolates. The MLST scheme was performed with two housekeeping genes (hemD and mdh) combined with two virulence genes (ssaQ and slyA) to improve the discriminatory power of method. Both methods presented high discriminatory indexes calculated by Simpson's index of diversity, 0.99 and 0.88 for FAFLP and MLST, respectively. These methods were efficient to differentiate isolates of distinct Salmonella serovars, but did not distinguish isolates probable epidemiologically non-related, and also did not group isolates of same phage type. These results suggested that these two techniques can be used as a tool for the epidemiological molecular characterization of S. Enteritidis isolates.

Research paper thumbnail of Sorologia para Toxoplasmose em Gestantes e Recém-Nascidos em Santo Antônio da Patrulha, Rio Grande do Sul

Clinical & Biomedical Research, 2014

Introdução: Testes sorológicos têm sido utilizados para detectar a presença de possíveis agentes ... more Introdução: Testes sorológicos têm sido utilizados para detectar a presença de possíveis agentes etiológicos infecciosos durante a gestação. Esse estudo avaliou o perfil sorológico para toxoplasmose em gestantes e recém-nascidos e correlacionou a faixa etária das gestantes com soroprevalência. Métodos: Foi realizado um estudo transversal prospectivo sobre o perfil sorológico IgM e IgG anti-Toxoplasma gondii em 197 gestantes e seus respectivos recém-nascidos atendidos no Hospital Santo Antônio, localizado em Santo Antônio da Patrulha (RS) entre fevereiro e outubro de 2011, através do método de imunofluorescência indireta. Foi realizado cálculo da taxa de prevalência e respectivos intervalos de confiança de 95%. Resultados: A idade média das gestantes estudadas foi de 25,9 anos. Soropositividade para toxoplasmose foi encontrada em 105 (53,3%) das 197 amostras. Nenhum caso de IgM reagente foi encontrado no presente estudo. Não se identificou associação estatisticamente significativa entre soropositividade e faixa etária das mulheres (p=0,343). Conclusões: Medidas educativas voltadas para as gestantes suscetíveis à toxoplasmose devem ser desenvolvidas desde o primeiro pré-natal, visando orientá-las quanto ao risco de infecção, diminuindo assim o risco de soroconversão durante a gravidez.

Research paper thumbnail of Differentiation of Salmonella Enteritidis Isolates by Fluorescent Amplified Fragment Length Polymorphism

Foodborne Pathogens and Disease, 2011

Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the mole... more Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the molecular characterization of isolates is an important tool for epidemiological studies. Fluorescent amplified fragment length polymorphism (FAFLP) analysis was performed on 31 Salmonella Enteritidis strains from South Brazil isolated from human, foods, swine, broiler carcasses, and other poultry-related samples to subtype isolates in comparison to pulsed-field gel electrophoresis (PFGE) analysis. Five strains of Salmonella Enteritidis from different geographical regions, Salmonella Enteritidis ATCC 13076, and four isolates of different Salmonella serovars were also tested. Among the 41 isolates tested, 96 polymorphic AFs and 40 distinct profiles were obtained, displaying a Simpson's index of diversity of 0.99; whereas the PFGE analysis presented 13 patterns and the resulting Simpson's index was 0.55. Nine FAFLP and seven PFGE clusters could be inferred based in Dice similarity coefficient. FAFLP clustering readily identified different serotypes of Salmonella but did not distinguish isolates epidemiologically nonrelated or distinct phage types. Therefore, these results indicate that FAFLP is a rapid method for epidemiological investigations of Salmonella outbreaks, presenting a high discriminatory power for subtyping of Salmonella Enteritidis.

Research paper thumbnail of Characterization of variants of Bradyrhizobium elkanii and B. japonicum and symbiotic behaviour in soybeans

Ciência Rural, 2004

Variation in rhizobia strains isn’t a desirable fact based mainly on the possibility of unexpecte... more Variation in rhizobia strains isn’t a desirable fact based mainly on the possibility of unexpected results on legume inoculation. In this work, we studied the variability on phenotypic characteristics and genetic stability of rhizobia strains recommended for soybean inoculation. Variants with stable colony morphology were obtained from Bradyrhizobium japonicum strain SEMIA 5080 and from B. elkanii SEMIA 5019. Variants from SEMIA 587 obtained by another author were also used. The variants differed on colony characteristics, nodulation capacity, nitrogen fixation efficiency and competitive ability for nodule formation in two soybean varieties (Jacui 7 and IAS 5). Symbiotic behavior varied according to plant variety. Only the variants 5019 G and 5019 P differed on the isoenzymatic profile. There were differences in antibiotic resistance between variants from two strains. Correlation between symbiotic characteristics and colony morphology or antibiotic resistance wasn’t conclusive. The ...

Research paper thumbnail of Differentiation ofSalmonellaEnteritidis Isolates by Fluorescent Amplified Fragment Length Polymorphism

Foodborne Pathogens and Disease, 2011

Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the mole... more Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the molecular characterization of isolates is an important tool for epidemiological studies. Fluorescent amplified fragment length polymorphism (FAFLP) analysis was performed on 31 Salmonella Enteritidis strains from South Brazil isolated from human, foods, swine, broiler carcasses, and other poultry-related samples to subtype isolates in comparison to pulsed-field gel electrophoresis (PFGE) analysis. Five strains of Salmonella Enteritidis from different geographical regions, Salmonella Enteritidis ATCC 13076, and four isolates of different Salmonella serovars were also tested. Among the 41 isolates tested, 96 polymorphic AFs and 40 distinct profiles were obtained, displaying a Simpson's index of diversity of 0.99; whereas the PFGE analysis presented 13 patterns and the resulting Simpson's index was 0.55. Nine FAFLP and seven PFGE clusters could be inferred based in Dice similarity coefficient. FAFLP clustering readily identified different serotypes of Salmonella but did not distinguish isolates epidemiologically nonrelated or distinct phage types. Therefore, these results indicate that FAFLP is a rapid method for epidemiological investigations of Salmonella outbreaks, presenting a high discriminatory power for subtyping of Salmonella Enteritidis.

Research paper thumbnail of Avaliação da competitividade, entre isolados de Bradyrhizobiumjaponicum, e expressão da fixação simbiótica em soja

Research paper thumbnail of Serology for toxoplaSmoSiS in pregnant women and newbornS from Santo antônio da patrulha, rio grande do Sul, brazil

Introduction: Serological tests have been used to detect the presence of possible etiologic agent... more Introduction: Serological tests have been used to detect the presence of possible etiologic agents during pregnancy. This study aimed to evaluate the serological profile of toxoplasmosis in pregnant women and newborns and to correlate women’s age group with seroprevalence.

Research paper thumbnail of Diversidade genética de isolados de Salmonella Enteritidis avaliada por FAFLP (Análise de fragmentos polimórficos amplificados e fluorescentes) e MLST (Tipificação por sequenciamento de múltiplos loci)

Salmonella Enteritidis is a common foodborne pathogen that causes gastroenteritis and systemic in... more Salmonella Enteritidis is a common foodborne pathogen that causes gastroenteritis and systemic infections in humans. The characterization of this bacterium is essential for epidemiological studies. In this context, two molecular methods, MLST and FAFLP, were tested for characterization of 32 S. Enteritidis isolates obtained from South of Brazil, as well as five isolates obtained from other geographical areas. Four isolates of different serovars of Salmonella (S. Panama, S. Senftenberg, S. Typhimurium and Salmonella [4,5:-:1,2]) were included as outgroup. These two techniques were already used to analyze different Salmonella serovars, but this study is the first to use them to discriminate the same S. Enteritidis isolates. The MLST scheme was performed with two housekeeping genes (hemD and mdh) combined with two virulence genes (ssaQ and slyA) to improve the discriminatory power of method. Both methods presented high discriminatory indexes calculated by Simpson's index of diversity, 0.99 and 0.88 for FAFLP and MLST, respectively. These methods were efficient to differentiate isolates of distinct Salmonella serovars, but did not distinguish isolates probable epidemiologically non-related, and also did not group isolates of same phage type. These results suggested that these two techniques can be used as a tool for the epidemiological molecular characterization of S. Enteritidis isolates.

Research paper thumbnail of Sorologia para Toxoplasmose em Gestantes e Recém-Nascidos em Santo Antônio da Patrulha, Rio Grande do Sul

Clinical & Biomedical Research, 2014

Introdução: Testes sorológicos têm sido utilizados para detectar a presença de possíveis agentes ... more Introdução: Testes sorológicos têm sido utilizados para detectar a presença de possíveis agentes etiológicos infecciosos durante a gestação. Esse estudo avaliou o perfil sorológico para toxoplasmose em gestantes e recém-nascidos e correlacionou a faixa etária das gestantes com soroprevalência. Métodos: Foi realizado um estudo transversal prospectivo sobre o perfil sorológico IgM e IgG anti-Toxoplasma gondii em 197 gestantes e seus respectivos recém-nascidos atendidos no Hospital Santo Antônio, localizado em Santo Antônio da Patrulha (RS) entre fevereiro e outubro de 2011, através do método de imunofluorescência indireta. Foi realizado cálculo da taxa de prevalência e respectivos intervalos de confiança de 95%. Resultados: A idade média das gestantes estudadas foi de 25,9 anos. Soropositividade para toxoplasmose foi encontrada em 105 (53,3%) das 197 amostras. Nenhum caso de IgM reagente foi encontrado no presente estudo. Não se identificou associação estatisticamente significativa entre soropositividade e faixa etária das mulheres (p=0,343). Conclusões: Medidas educativas voltadas para as gestantes suscetíveis à toxoplasmose devem ser desenvolvidas desde o primeiro pré-natal, visando orientá-las quanto ao risco de infecção, diminuindo assim o risco de soroconversão durante a gravidez.

Research paper thumbnail of Differentiation of Salmonella Enteritidis Isolates by Fluorescent Amplified Fragment Length Polymorphism

Foodborne Pathogens and Disease, 2011

Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the mole... more Salmonella Enteritidis is responsible for human gastroenteritis outbreaks worldwide, and the molecular characterization of isolates is an important tool for epidemiological studies. Fluorescent amplified fragment length polymorphism (FAFLP) analysis was performed on 31 Salmonella Enteritidis strains from South Brazil isolated from human, foods, swine, broiler carcasses, and other poultry-related samples to subtype isolates in comparison to pulsed-field gel electrophoresis (PFGE) analysis. Five strains of Salmonella Enteritidis from different geographical regions, Salmonella Enteritidis ATCC 13076, and four isolates of different Salmonella serovars were also tested. Among the 41 isolates tested, 96 polymorphic AFs and 40 distinct profiles were obtained, displaying a Simpson's index of diversity of 0.99; whereas the PFGE analysis presented 13 patterns and the resulting Simpson's index was 0.55. Nine FAFLP and seven PFGE clusters could be inferred based in Dice similarity coefficient. FAFLP clustering readily identified different serotypes of Salmonella but did not distinguish isolates epidemiologically nonrelated or distinct phage types. Therefore, these results indicate that FAFLP is a rapid method for epidemiological investigations of Salmonella outbreaks, presenting a high discriminatory power for subtyping of Salmonella Enteritidis.

Research paper thumbnail of Characterization of variants of Bradyrhizobium elkanii and B. japonicum and symbiotic behaviour in soybeans

Ciência Rural, 2004

Variation in rhizobia strains isn’t a desirable fact based mainly on the possibility of unexpecte... more Variation in rhizobia strains isn’t a desirable fact based mainly on the possibility of unexpected results on legume inoculation. In this work, we studied the variability on phenotypic characteristics and genetic stability of rhizobia strains recommended for soybean inoculation. Variants with stable colony morphology were obtained from Bradyrhizobium japonicum strain SEMIA 5080 and from B. elkanii SEMIA 5019. Variants from SEMIA 587 obtained by another author were also used. The variants differed on colony characteristics, nodulation capacity, nitrogen fixation efficiency and competitive ability for nodule formation in two soybean varieties (Jacui 7 and IAS 5). Symbiotic behavior varied according to plant variety. Only the variants 5019 G and 5019 P differed on the isoenzymatic profile. There were differences in antibiotic resistance between variants from two strains. Correlation between symbiotic characteristics and colony morphology or antibiotic resistance wasn’t conclusive. The ...