Made available in DSpace on 2014-06-11T19:30:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-23Bitstream added on 2014-06-13T18:40:42Z : No. of bitstreams: 1 sakabe_r_dr_jabo.pdf: 1962870 bytes, checksum: cd990c2bf904dcaef626cdef3948aa0c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este ensaio teve como objetivo avaliar a suplementação alimentar com dois óleos vegetais (soja e linhaça) e parede celular de Saccharomyces cerevisiae em tilápias do Nilo sobre o desempenho produtivo, inflamação aguda induzida por Streptococcus agalactiae inativado, inflamação crônica por corpo estranho por meio do implante de lamínulas de vidro no tecido subcutâneo e a taxa de sobrevivência frente ao desafio com S. agalactiae. Foram utilizadas 840 tilápias, invertidas sexualmente, distribuídas em 24 caixas de 500L (n=35). O delineamento utilizado foi o inteiramente casualizado com oito tratamentos e três repetições, no qual foram testadas duas fontes de ácidos graxos essenciais (óleo de soja (OS) e óleo de linhaça (OL)) e dois níveis de parede celular de S. cerevisiae (PC) na dieta (0,0 e 0,3%) constituindo os seguintes tratamentos: OS; OL; OS+OL; OS+PC; OL+PC; OS+OL+PC; PC e controle. Os peixes receberam as rações teste durante três meses, duas vezes ao dia, ad libitum. Um lote de peixes foi avaliado quanto ao acúmulo de células na inflamação induzida por S. agalactiae inativado, na bexiga natatória após 12, 24 e 48 horas. O segundo lote de peixes foi submetido ao implante de lamínulas de vidro no tecido subcutâneo por dois, quatro, seis e oito dias, quando foram colhidas e avaliadas quanto ao acúmulo de macrófagos e formação de gigantócitos. Dentre os parâmetros hematológicos foi realizado eritrograma completo (contagem de células vermelhas, percentual de hematócrito e taxa de hemoglobina). Além disso, foi avaliada a atividade respiratória de leucócitos sanguíneos. No terceiro lote de peixes, foram avaliados os parâmetros de desempenho produtivo e a sobrevivência frente ao desafio bacteriano com S. agalactiae. No estudo da inflamação aguda constatou-se o efeito da suplementação alimentar com os óleos vegetais (soja e/ou linhaça)... / This test was designed to evaluate dietary supplementation with two vegetable oils (soybean and linseed) and cell wall of Saccharomyces cerevisiae in Nile tilapia growth performance, acute inflammation induced by Streptococcus agalactiae inactivated, chronic inflammation of foreign body through implantation of glass coverslips into the subcutaneous tissue and survival upon challenge with S. agalactiae. 840 tilapia, sexually inverted, were distributed into 24 aquarium of 500L (n = 35). The design was completely randomized with eight treatments and three replicates which two sources of essential fatty acids (soybean oil (SO) and linseed oil (LO)) and two levels of the cell wall of S. cerevisiae (PC) in diet (0.0 and 0.3%), and tested to the following treatments: OS, OL, OL + OS, OS + PC, PC + OL; OS + OL + PC, PC and control. The fish were fed with diets for three months, twice daily, ad libitum. In one group of fish the accumulation of cells in the inflammation induced by S. agalactiae inactivated in bladder after 12, 24 and 48 hours were evaluated. The second group of fish was subjected to implantation of glass coverslips into the subcutaneous tissue by two, four, six and eight days when they were harvested and evaluated for macrophage accumulation and formation of giant cell. Among the hematological parameters the complete erythrocyte (red blood cell count, percentage of hematocrit and hemoglobin) was performed. Furthermore, the respiratory activity of blood leukocytes was evaluated. The third group of fish, the productive performance parameters and survival to the bacterial challenge with S. agalactiae was evaluated. In the study of acute inflammation was found the effect of dietary supplementation with vegetable oils (soybean and / or linseed), as well as the yeast cell wall increased accumulation of total cells in the exudate of the swim bladder... (Complete abstract click electronic access below)

Streptococcus agalactiae est la première cause d’infections néonatales, et est aussi un pathogène émergent chez l’adulte immunodéprimé. L’objectif de ce travail de thèse a été de caractériser l’opéron métabolique fru2 de S. agalactiae (i) en étudiant sa phylogénie, (ii) en identifiant ses inducteurs, et (iii) en élaborant son schéma de régulation. Cet opéron est composé de 7 gènes qui codent un activateur transcriptionnel de la famille DeoR-like (Fru2R), un transporteur PTS (PTSFru2), et trois enzymes qui sont potentiellement impliquées dans la voie non oxydative des pentoses phosphates. Nous avons mis en évidence que cet opéron avait été acquis au cours de l’évolution, et n’était présent que chez les souches de complexes clonaux responsables d’infections chez l’adulte immunodéprimé et la personne âgée. Nous avons ensuite montré que certains milieux complexes, sources de carbone, et liquides biologiques humains permettaient l’activation de cet opéron. Ensuite, nous avons caractérisé le rôle et fonctionnement de la protéine Fru2R (i) en montrant son rôle d’activateur transcriptionnel, (ii) en identifiant les acides aminés essentiels à son activité, et (iii) en démontrant sa capacité à se fixer au niveau de la région promotrice de fru2. / Streptococcus agalactiae, commonly known as group B streptococcus, is a leading cause of neonatal morbidity and mortality. It is also an emergent pathogen in immunocompromised and elderly adults. The objective of this study was to characterize the phylogeny, the induction and the regulation of the S. agalactiae fru2 operon. This operon encodes a PTS transporter of the fructose-mannitol family, a transcriptional activator of the DeoR-like family, an allulose-6 phosphate-3-epimerase, a transaldolase and a transketolase. Our results, concerning the phylogeny, indicate that fru2 was acquired during the evolution of S. agalactiae. Then, we highlighted that the fru2 promoter was active in complex medium, in chemically defined medium with various carbon sources and in human biological fluids. Then, we demonstrated that the Fru2R protein (i) was a transcriptional activator, (ii) contains amino acids which are essential for the activity of the Fru2R and fru2 promoter, and (iii) interacts with the fru2 intergenic region. Then, we demonstrated the role of the PTSFru2 proteins of S. agalactiae A909 fru2.

Submitted by Rodolfo Santos Rossi null (rodolfosrossi@gmail.com) on 2017-06-20T19:44:52Z No. of bitstreams: 1 Rossi - Dissertação Repositório UNESP.pdf: 1649974 bytes, checksum: eab3c6db952f25d7d6aa51700765d11b (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-06-21T14:07:38Z (GMT) No. of bitstreams: 1 rossi_rs_me_bot.pdf: 1649974 bytes, checksum: eab3c6db952f25d7d6aa51700765d11b (MD5) / Made available in DSpace on 2017-06-21T14:07:38Z (GMT). No. of bitstreams: 1 rossi_rs_me_bot.pdf: 1649974 bytes, checksum: eab3c6db952f25d7d6aa51700765d11b (MD5) Previous issue date: 2017-04-27 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo deste estudo foi avaliar novas estratégias de identificação e tratamento de mastite subclínica causada por Streptococcus agalactiae. Dois estudos foram conduzidos para alcançar os objetivos propostos: 1) um ensaio clínico randomizado, para avaliar a eficácia do tratamento de S. agalactiae com cloxacilina intramamária (CLOXIMM), cefquinoma intramamária (CEFIMM) e cefquinoma intramuscular (CEFIM); e avaliar a não-inferioridade da CLOXIMM em relação a CEFIMM. E, 2) um estudo de acurácia diagnóstica, para estimar a acurácia do Somaticell, California Mastitis Test (CMT) e do exame microbiológico do leite composto (leite dos quatro quartos) na detecção de quartos e animais infectados com S. agalactiae. Os resultados indicaram que quartos tratados com CEFIM apresentaram menor taxa de cura bacteriológica (55%) do que aqueles tratados com CLOXIMM (86%) ou CEFIMM (98%). A diferença na proporção de cura bacteriológica entre CEFIMM e CLOXIMM foi de 0,121 (intervalo de confiança de 95%: 0,056 - 0,184). A CLOXIMM foi considerada não inferior a CEFIMM quando margens de não inferioridade de 0,20 e 0,25 foram utilizadas. Contudo, a determinação da não inferioridade foi inconclusiva para margens de 0,10 e 0,15. A cultura do leite composto apresentou acurácia diagnóstica satisfatória (95,7%) quando comparada a cultura individual por quarto. Para identificação dos quartos infectados com S. agalactiae, o ponto de corte considerado mais adequado foi de 205.000 células/mL para o teste Somaticell e escore 1 para o teste CMT. O teste Somaticell foi considerado mais acurado para uso em programas de erradicação, pois apresentou maior sensibilidade e menor proporção de resultados falso-negativos. Resultados deste estudo podem ser aplicados diretamente em nível de campo, para aumentar a eficiência de programas de erradicação de S. agalactiae. / The objective of the present study was to assess new strategies to identify and treat Streptococcus agalactiae subclinical mastitis. Two studies were conducted to achieve the proposed objectives: 1) a randomized clinical trial, to assess the efficacy of intramammary cloxacillin (CLOXIMM), intramammary cefquinome (CEFIMM), and intramuscular cefquinome (CEFIM), to treat S. agalactiae intramammary infections (IMI); and assess whether CLOXIMM was non-inferior to CEFIMM to treat S. agalactiae IMI. And, 2) a diagnostic accuracy study, to estimate the accuracy of the Somaticell, California Mastitis Test (CMT), and the composite milk microbiological examination of milk to detect S. agalactiae IMI. Results indicated that the bacteriological cure rate was lower for quarters treated with CEFIM (55%), as compared with CLOXIMM (86%) or CEFIMM (98%). The bacteriological cure difference between CEFIMM and CLOXIMM was 0.121 (95% confidence interval: 0.056 - 0.184). The CLOXIMM was considered non-inferior to CEFIMM when the non-inferiority margins of 0.20 and 0.25 were considered. Nevertheless, determination of non-inferiority was inconclusive for margins of 0.10 and 0.15. Microbiological examination of composite milk was of high accuracy (95.7%), as compared with microbiological examination of quarter milk samples. The thresholds of 205,000 cells/mL for the Somaticell and of score 1 for the CMT can be considered the most appropriate for diagnosing S. agalactiae IMI. The higher sensitivity and lower proportion of false-negative results are characteristics that can justify the use of the Somaticell in S. agalactiae eradication programs, as an alternative to the CMT. Results of this study can be directly applied at the farm level, to improve the efficiency of S. agalactiae eradication programs. / CNPq: 132538-2015-6

Orientador: Flávio Ruas de Moraes / Banca: Margaria Maria Barros / Banca: Júlio Hermann Leonhardt / Banca: Maria José Tavares Ranzani de Paiva / Banca: Newton Castagnolli / Resumo: O presente trabalho teve por objetivos avaliar a inter-relação entre a suplementação alimentar com 0,3% de parede celular de levedura e vacinação com extrato oleoso de Streptococcus agalactiae sobre o desempenho produtivo, parâmetros fisiopatológicos e componente celular inflamatório em tilápia do Nilo. Oitenta e quatro tilápia com peso médio inicial de 125,0 + 1,5g foram distribuídas em 12 caixas de fibra, seguindo o esquema fatorial 2x2x3, correspondente a dois níveis de parede celular de levedura (0,0 e 0,3% parede celular), dois tratamentos (solução salina e vacina) e três coletas após o desafio com a bactéria viva (seis, 24 e 48h) com sete repetições. Os peixes foram alimentados durante 77 dias. A vacinação foi realizada 60 dias após o início da alimentação, por meio da inoculação intraperitoneal de 0,5 mL da vacina contendo 108 UFC/mL. Após 15 dias da vacinação, todos os peixes foram submetidos ao desafio com Streptococcus agalactiae vivo, por meio da inoculação intraperitoneal de 108 UFC/mL, veiculadas em 0,5 mL de solução salina (0,85%). As análises do desempenho produtivo mostraram que a suplementação dietética com parede celular de levedura associada à vacinação não influenciou o desempenho produtivo da tilápia do Nilo e o melhor desempenho ocorreu na utilização da parede celular de levedura. Os parâmetros hematológicos mostraram que a suplementação com 0,3% de parede celular de levedura associada à vacinação contra Streptococcus agalactiae em tilápia do Nilo foi essencial para incrementar a hematopoiese. A suplementação alimentar com 0,3% de parede celular de levedura associada à vacinação melhorou a resposta de defesa dos peixes, no que se refere à inflamação aguda e destaca a importância da vacinação. / Abstract: The work evaluates the interrelation between supplementation diets with 0,3% of cellular wall of yeast and vaccination with oily extract of Streptococcus agalactiae in the growth performance, phisiopathological parameters and inflamatory cellular component of Nile tilapia (Oreochromis niloticus). Eighty four tilapia with initial average weight of 125,0 ± 1,5g were distributed in 12 fiber aquaria, following the factorial design 2x2x3, corresponding to two levels of cellular wall of yeast (0,0 and 0,3% cellular wall), two treatments (saline solution and vaccine) and three collections, after challenge with bacteria (six, 24 and 48h) with seven repetitions. Fish were fed during 77 days. The vaccination was accomplished 60 days after the beginning of the feeding, through inoculation intraperitoneal of 0,5 mL of the vaccine containing 108 UFC/mL. After 15 days of the vaccination, all fishes were challenged with Streptococcus agalactiae, through inoculation intraperitoneal of 108 UFC/ml, diluted in 0,5 mL of saline solution (0,85%). The analyses of the pattern performance showed that supplementation diets with cellular wall of yeast associated to vaccination did not influence the growth performance of Nile tilapia and the best growth performance was obtained using cellular wall of yeast. The phisiopathological parameters showed supplementation diets with 0,3% of cellular wall of yeast associated to the vaccination against Streptococcus agalactiae in Nile tilapia were essential to increase the hematopoiesis. The supplementation diets with 0,3% of cellular wall of yeast associated to the vaccination improved the immune response of fish, in relation to the sharp inflammation and it detaches the importance of the vaccination. / Doutor

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-04-04T20:58:01Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PesquisaStreptococcusAgalactiae.pdf: 37926140 bytes, checksum: 593f901741610227708bc44798685330 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-04-05T12:36:13Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PesquisaStreptococcusAgalactiae.pdf: 37926140 bytes, checksum: 593f901741610227708bc44798685330 (MD5) / Made available in DSpace on 2013-04-05T12:36:14Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PesquisaStreptococcusAgalactiae.pdf: 37926140 bytes, checksum: 593f901741610227708bc44798685330 (MD5) Previous issue date: 2003 / Na infecção por Streptococcus agalactiae são reconhecidas duas formas neonatais, a de início precoce, cujo quadro clínico é caracterizado por bacteremia com envolvimento pulmonar, meningite é a manifestação clínica predominante. Considerando-se a gravidade da patologia, o desconhecimento da incidência desta bactéria em gestantes residentes na região Norte do Brasil e a importância do seu diagnóstico em exames pré-natais, é fundamental a determinação da ocorrência dos estreptococos do B neste referido grupo populacional. Portanto, este estudo objetivou a realização do diagnóstico laboratorial de Streptococcus agalactiae no trato genital feminino de gestantes, no último trimestre de gestação, determinando a incidência e alertando sobre a importância do diagnóstico no exame pré-natal. O estudo foi realizado no período de fevereiro a agosto de 2002, em 50 gestantes voluntárias residentes e domiciliadas na cidade de Belém-Pará, procedentes do setor de Tocoginecologia da Universidade Federal do Pará, e a identificação da bactéria foi realizada através da bacterioscopia e da cultura do conteúdo vaginal. Das 50 gestantes estudadas, sete (14 %) apresentavam cultura positiva para Streptococcus agalactiae. Destas, duas (28,6 %) eram primigestas e cinco (71,4 %) secundigestas. Os resultados obtidos indicaram a presença significativa da bactéria, indicando a necessidade da adoção de medidas profiláticas da infecção por este agente, devido às altas taxas de morbidade e mortalidade associadas ao estreptococo do grupo B. / In the Steptococus agalactiaie infections in newly born two forms are recognized, that of precocious beginning, whose clinical picture is characterized by bacteremia with lung involvement, meningitis, septic shock and neutropenia, and the of late beginning, where the bacteremia associated to the meningitis is the predominant clinical manifestation. Being considered the gravity of the pathology, the absence of information about the incidence of this bacterium in resident pregnant women in the north area of Brazil and the importance of diagnosis, is fundamental the determination of the occurrence of the estreptococos of the group B in this population. Therefore, this study aimed the laboratorial diagnosis of streptocuccus agalactiae in the pregnant women feminine genital treat, in the last quarter of gestation, determining the incidence and alerting about the importance of the diagnosis in the prenatal exam. This study was realized in the period of February to August of 2002, in 50 pregnant women resident and domiciled in the city of Belem-Para, coming from the section of gynecology of the Federal University of Para. The bacteria identification carry out through the bacterioscopy and culture of the vaginal contents. Of the 50 studied pregnant women, seven (14%) presented positive culture for Streptococcus agalactiae. Of these, two (28,6%) were first gestation and five (71,4%) second gestation. This results to indication the significant presence of the bacterium, indicating the need of the adoption procedures for prevention of the infection by this agent, due the high index morbidade and mortality associated to the estreptococo of the group B.

Resumo: Este ensaio teve como objetivo avaliar a suplementação alimentar com dois óleos vegetais (soja e linhaça) e parede celular de Saccharomyces cerevisiae em tilápias do Nilo sobre o desempenho produtivo, inflamação aguda induzida por Streptococcus agalactiae inativado, inflamação crônica por corpo estranho por meio do implante de lamínulas de vidro no tecido subcutâneo e a taxa de sobrevivência frente ao desafio com S. agalactiae. Foram utilizadas 840 tilápias, invertidas sexualmente, distribuídas em 24 caixas de 500L (n=35). O delineamento utilizado foi o inteiramente casualizado com oito tratamentos e três repetições, no qual foram testadas duas fontes de ácidos graxos essenciais (óleo de soja (OS) e óleo de linhaça (OL)) e dois níveis de parede celular de S. cerevisiae (PC) na dieta (0,0 e 0,3%) constituindo os seguintes tratamentos: OS; OL; OS+OL; OS+PC; OL+PC; OS+OL+PC; PC e controle. Os peixes receberam as rações teste durante três meses, duas vezes ao dia, ad libitum. Um lote de peixes foi avaliado quanto ao acúmulo de células na inflamação induzida por S. agalactiae inativado, na bexiga natatória após 12, 24 e 48 horas. O segundo lote de peixes foi submetido ao implante de lamínulas de vidro no tecido subcutâneo por dois, quatro, seis e oito dias, quando foram colhidas e avaliadas quanto ao acúmulo de macrófagos e formação de gigantócitos. Dentre os parâmetros hematológicos foi realizado eritrograma completo (contagem de células vermelhas, percentual de hematócrito e taxa de hemoglobina). Além disso, foi avaliada a atividade respiratória de leucócitos sanguíneos. No terceiro lote de peixes, foram avaliados os parâmetros de desempenho produtivo e a sobrevivência frente ao desafio bacteriano com S. agalactiae. No estudo da inflamação aguda constatou-se o efeito da suplementação alimentar com os óleos vegetais (soja e/ou linhaça) ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This test was designed to evaluate dietary supplementation with two vegetable oils (soybean and linseed) and cell wall of Saccharomyces cerevisiae in Nile tilapia growth performance, acute inflammation induced by Streptococcus agalactiae inactivated, chronic inflammation of foreign body through implantation of glass coverslips into the subcutaneous tissue and survival upon challenge with S. agalactiae. 840 tilapia, sexually inverted, were distributed into 24 aquarium of 500L (n = 35). The design was completely randomized with eight treatments and three replicates which two sources of essential fatty acids (soybean oil (SO) and linseed oil (LO)) and two levels of the cell wall of S. cerevisiae (PC) in diet (0.0 and 0.3%), and tested to the following treatments: OS, OL, OL + OS, OS + PC, PC + OL; OS + OL + PC, PC and control. The fish were fed with diets for three months, twice daily, ad libitum. In one group of fish the accumulation of cells in the inflammation induced by S. agalactiae inactivated in bladder after 12, 24 and 48 hours were evaluated. The second group of fish was subjected to implantation of glass coverslips into the subcutaneous tissue by two, four, six and eight days when they were harvested and evaluated for macrophage accumulation and formation of giant cell. Among the hematological parameters the complete erythrocyte (red blood cell count, percentage of hematocrit and hemoglobin) was performed. Furthermore, the respiratory activity of blood leukocytes was evaluated. The third group of fish, the productive performance parameters and survival to the bacterial challenge with S. agalactiae was evaluated. In the study of acute inflammation was found the effect of dietary supplementation with vegetable oils (soybean and / or linseed), as well as the yeast cell wall increased accumulation of total cells in the exudate of the swim bladder... (Complete abstract click electronic access below) / Orientador: Flávio Ruas de Moraes / Coorientador: Fabiana Pilarski / Banca: Ana Lúcia Salaro / Banca: Áureo Evangelista Santana / Banca: Marco Antônio de Andrade Belo / Banca: Margarida Maria Barros / Doutor

Thesis (MTech (Biomedical Sciences))--Cape Peninsula University of Technology, 2015. / BACKGROUND AND OBJECTIVES: Group B Streptococci (GBS) can asymptomatically colonise the vagina and rectum of women. Studies have shown that this bacterium is the leading cause of septicemia, meningitis and pneumonia in neonates. In Namibia no known studies have investigated GBS colonisation and the antibiotic resistance profile of GBS isolates in pregnant women. This study accessed the GBS colonisation rate amongst the pregnant women who attended the Windhoek Central Hospital Antenatal Clinic (Khomas region), in Namibia for a period of 13 months. Furthermore, using the VITEK 2 system, the GBS isolates were tested against the following antimicrobial substances; benzylpenicillin, ampicillin, clindamycin, erythromycin, tetracycline, vancomycin, cefotaxime, ceftriaxone, linezolid and trimethoprim/sulfamethoxazole. Penicillin G is the drug of choice in the majority of studies, and seems to be the most effective drug for intrapartum antibiotic prophylaxis (IAP). All the GBS isolates found in this study were also analysed for the presence of selected genes known to be associated with resistance to key antibiotics using specific primers within a polymerase chain reaction (PCR).

Orientador: Renato Passini Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-04T01:25:35Z (GMT). No. of bitstreams: 1 Nomura_MarceloLuis_D.pdf: 838174 bytes, checksum: a795b39457b62a18ecb17c4609ece12d (MD5) Previous issue date: 2004 / Resumo: Objetivos: Identificar a taxa de prevalência e fatores de risco de colonização materna por estreptococo do grupo B (EGB) em gestantes com trabalho de parto prematuro (TPP) e/ou ruptura prematura pré-termo de membranas (RPM). Métodos: Foram colhidos dois swabs anais e vaginais de 203 gestantes atendidas no CAISM-UNICAMP. Um swab de cada local foi colocado em meio de transporte e enviados para cultura em placas de ágar-sangue, os outros dois foram incubados por 24 horas em meio de Todd-Hewitt para posterior semeadura em placas de ágar-sangue. Resultados: A prevalência de colonização materna por EGB foi de 27,6% (56 gestantes). As taxas de colonização por diagnóstico foram 34,7% para RPM, 25,2% para TPP e 17,8% para TPP + RPM. As variáveis raça branca, baixo nível de escolaridade e infecção urinária foram associadas a maiores taxas de colonização na análise multivariada. A presença de infecção urinária foi a única variável significativamente associada à colonização materna na análise multivariada. A taxa de detecção do estreptococo do grupo B foi significativamente maior com o uso do meio seletivo e com a associação de coleta de culturas anais e vaginais. A taxa de colonização neonatal foi de 3,1%. Ocorreram dois casos de sepse precoce por EGB nesta amostra, com prevalência estimada de 10,8 casos por mil nascidos vivos e mortalidade de 50%. Conclusão: A amostra avaliada apresenta altas taxas de colonização materna por Streptococcus agalactiae. É necessário o uso de meio de cultura seletivo e a associação de culturas anorretais e vaginais para aumentar a taxa de detecção do EGB. A incidência de sepse neonatal precoce foi elevada nesta população / Abstract: Objective: to study group B streptococcus maternal colonization rates and risk factors in women with preterm labor (PTL) and preterm premature rupture of membranes (PROM). Methods: Vaginal and anal swabs (two of each) were colected from 203 women followed at CAISM-UNICAMP. One of each swab was placed in transport media and then cultured in blood-agar plates, the other swabs were incubated in Todd-Hewitt selective media for 24 hours and then subcultured in blood-agar plates. Results: Maternal colonization rate was 27.6% (56 women). Colonization rates by admission diagnosis were 34.7% in PROM, 25.2% in PTL and 17.8% in PTL and PROM. White race, less than elementary education level and urinary tract infection were associated with maternal colonization in the univariate analysis. Urinary tract infection was the only variable associated with maternal colonization in a multivariate analysis. GBS detection rates were significantly higher with the use of selective culture media and with sampling of both vaginal and anorectal sites. Neonatal colonization rate was 3.1%. There were two cases of early-onset neoanatal sepsis caused by GBS, with an estimated prevalence of 10.8 cases per thousand live borns and a mortality rate of 50%. Conclusions: This sample of women had high GBS colonization rates. The use of selective culture media and collection of both anal and vaginal samples is necessary in order to maximize GBS detection rates. Early-onset neonatal sepsis incidence was high in this population / Doutorado / Tocoginecologia / Doutor em Tocoginecologia

Streptococcus agalactiae is a pathogen of multiple hosts. The bacterium, an aetiological agent of septicaemia and meningo-encephalitis in freshwater and saltwater fish species, is considered a major threat to the aquaculture industry, particularly for tilapia. Cattle and humans are however the main known reservoirs for S. agalactiae. In humans, the bacterium (commonly referred to as Group B Streptococcus or GBS) is a member of the commensal microflora of the intestinal and genito-urinary tracts, but it is also a major cause of neonatal invasive disease and an emerging pathogen in adults. In cattle, S. agalactiae is a well-recognized causative agent of mastitis. Numerous studies focusing on S. agalactiae from human and bovine origins have provided insight into the population structure of the bacterium, as well as the genome content and pathogenic mechanisms through identification of virulence determinants. Concerning S. agalactiae from aquatic origins, scientific information mainly focused on case reporting and/or experimental challenges, with a limited or absence of information in terms of pathogenesis, virulence determinants and genotypes of the strains involved. The objective of this study was to enhance our understanding of the molecular epidemiology, host-adaptation and pathogenicity of S. agalactiae in aquatic species, with particular emphasis on tilapia. Firstly, a collection of 33 piscine, amphibian and sea mammal isolates originating from several countries and continents was assembled, with the aim of exploring the population structure and potential host specificity of aquatic S. agalactiae. Isolates were characterised using pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), and a standardised 3-set genotyping system comprising molecular serotypes, surface protein gene profiles and mobile genetic element profiles. Two major subpopulations were identified in fish. The first subpopulation consisted of non-haemolytic isolates that belonged to sequence type (ST) 260 or 261, which are STs that have been reported only from teleosts. These isolates exhibited a low level of genetic diversity by PFGE and clustered with other STs that have been reported only in fish. Another common feature was the absence of all surface protein genes or mobile genetic elements targeted as part of the 3-set genotyping and that are usually found in human or bovine isolates. The second subpopulation consisted of β-haemolytic isolates recovered from fish, frogs and sea mammals, and that exhibited medium to high genetic diversity by PFGE. STs identified among these isolates have previously been identified from strains associated with asymptomatic carriage and invasive disease in humans. The human pathogenic strain ST7 serotype Ia was detected in fish from Asia. Moreover, ST283 serotype III-4 and its novel single locus variant ST491 detected in fish from Southeast Asia shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. These observations suggested that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. STs found among the seal isolates (ST23) have also been reported from humans and numerous other host species, but never from teleosts. This work provided an excellent basis for exploration of the virulence of selected strains in experimental challenges. The virulence of two strains of S. agalactiae was experimentally investigated by intra-peritoneal infection of Nile tilapia (Oreochromis niloticus), using an isolate originally recovered from fish and belonging to ST260, and an isolate originating from a grey seal and belonging to ST23. The clinical signs, the in vivo distribution of viable bacteria and bacterial antigens, and the gross and histopathological lesions that developed during the time course of the infection were investigated. The ST260 strain was highly virulent, whereas no major clinical sign or mortalities occurred in the fish challenged with the ST23 strain. After injection, both strains however gained access to the bloodstream and viable bacteria were recovered from all organs under investigation. During the early stages of infection, bacteria were mostly found within the reticulo-endothelial system of the spleen and kidney. Thereafter, the ST260 demonstrated a particular tropism for the brain and the heart, but granulomatous inflammation and associated necrotic lesions were observed in all organs. ST23 was responsible for a mixed inflammatory response associated with the presence of bacteria in the choroid rete and in the pancreatic tissue only. After 7 days post-challenge and for both strain, the formation or containment of bacteria within granulomata or other encapsulated structures appeared to be a major component of the fish response. However, the load of viable bacteria remained high within organs of fish infected with ST260, suggesting that, unlike ST23, this strain is able to survive within macrophages and/or to evade the immune system of the fish. This work demonstrates that the lack of report of ST23 strains in fish is possibly not due to a lack of exposure but to a lack of virulence in this host. The two strains, which differ in prevalence and virulence in fish, provide an excellent basis to investigate genomic differences underlying the host-association of distinct S. agalactiae subpopulations. The genome of the ST260 strain used in challenge studies was sequenced. We therefore provided the first description for the genome sequence of a non-haemolytic S. agalactiae isolated from tilapia (strain STIR-CD-17) and that belongs by multi-locus sequence typing (MLST) to clonal complex (CC) 552, which corresponds to a presumptive fish-adapted subgroup of S. agalactiae. The genome was compared to 13 S. agalactiae genomes of human (n=7), bovine (n=2), fish (n=3) and unknown (n=1) origins. Phylogenetic analysis based on the core genome identified isolates of CC552 as the most diverged of all S. agalactiae studied. Conversely, genomes from β-haemolytic isolates of CC7 recovered from fish were found to cluster with human isolates of CC7, further supporting the possibility that some strains may represent a zoonotic or anthroponotic hazard. Comparative analysis of the accessory genome enabled the identification of a cluster of genes uniquely shared between CC7 and CC552, which encode proteins that may provide enhanced fitness in specific niches. Other genes identified were specific to STIR-CD-17 or to CC552 based on genomic comparisons; however the extension of this analysis through the PCR screening of a larger population of S. agalactiae suggested that some of these genes may occasionally be present in isolates belonging to CC7. Some of these genes, occurring in clusters, exhibited typical signatures of mobile genetic elements, suggesting their acquisition through horizontal gene transfer. It is not possible to date to determine whether these genes were acquired through intraspecies transfer or through interspecies transfer from the aquatic environment. Finally, general features of STIR-CD-17 highlighted a distinctive genome characterised by an absence of well conserved insertion sequences, an abundance of pseudogenes, a smaller genomic size than normally observed among human or bovine S. agalactiae, and an apparent loss of metabolic functions considered conserved within the bacterial species, indicating that the fish-adapted subgroup of isolates (CC552) has undergone niche restriction. Finally, genes encoding recognised virulence factors in human S. agalactiae were selected and their presence and structural conservation was evaluated within the genome of STIR-CD-17.