A bronquite infecciosa é uma doença viral, aguda e altamente contagiosa que afeta as aves da espécie Gallus gallus, de todas as idades, causando grandes perdas econômicas devido à mortalidade, queda na produção e qualidade dos ovos. Variações na sequência de aminoácidos na região hipervariável da subunidadade S1 da proteína de espícula (S) levam à emergência de novos sorotipos do vírus da bronquite infecciosa das galinhas (IBV). Este estudo teve como objetivo seqüenciar parcialmente o gene S1 para determinar a relação filogenética entre amostras vacinais e de campo com o intuito de investigar os genótipos circulantes. Cento e sessenta amostras foram coletadas, na forma de pools, de plantéis sintomáticos durante 2009/2010. Cada pool continha tecidos de 3 a 5 aves e foram compostos por diferentes órgãos (traquéia, pulmões, rins, conteúdo entérico, trato reprodutivo e swabs traqueais). As amostras foram triadas para a presença de IBV utilizando-se uma nested RT-PCR, direcionada a região 3UTR. As amostras positivas, (n=89) foram submetidas a nova nested RT-PCR dirigida para o gene S, resultando em 10 amplicons de 390pb que foram então submetidos a seqüenciamento de DNA e análise filogenética. As amostras brasileiras segregaram-se em dois grupos filogenéticos: Massachusetts (Mass) e tipos marcadamente brasileiros. Seis amostras agruparam-se no grupo Mass, com vacinas vivas atenuadas utilizadas no Brasil. Quatro amostras agruparam com cepas de campo brasileiras previamente descritas (acesso no GeneBank: FJ791257 to FJ791273). A identidade de aminoácidos no grupo Mass variou de 98% a 100%, sugerindo a detecção de vírus vacinal. Enquanto que entre as amostras brasileiras e o grupo Mass, a variabilidade de aminoácidos foi de 79% a 81%. Esses resultados mostram uma variação importante em genótipos virais circulantes nos plantéis industriais avícolas brasileiros. Portanto, o presente estudo reforça a contínua emergência e disseminação de novas linhagens de IBV no Brasil e a importância de constantes pesquisas e monitoramento, para que se compreendam aos fenômenos de emergência de novas linhagens e suas consequências, bem como para otimizar as medidas de controle do vírus. / Infectious bronchitis is a viral disease, acute and highly contagious that affects birds of the Gallus gallus species, of all ages, causing huge economic losses due to mortality, drop in production and quality eggs. Differences between serotypes of IBV are due to variations in the amino acids sequence in S1 hypervariable region subunit of spike protein (S). This study aimed to partially sequence the S1 gene to determine the phylogenetic relationship between field and vaccine viral types, and to investigate circulating genotypes in Brazil. One hundred and sixty pool samples were collected from symptomatic flocks during 2009/2010. Each pool contained tissues from 3 to 5 birds and was composed by different organs (tracheas, lungs, kidneys, enteric contents, tract reproductive and tracheal swabs). Samples were screened for the presence of IBV using a nested RT-PCR targeted to the 3UTR. Positive samples (n=56) were submitted to a nested RT-PCR target to S gene resulting in 10 amplicons of 390pb that were then submitted to DNA sequencing and analysis. Brazilian IBV genotypes segregated in two phylogenetic groups: Massachusetts (Mass) and Brazilian types. Six samples clustered in the Mass group, with live attenuated vaccines used in Brazil. Four samples grouped with field Brazilian strains previously described (GeneBank accession: FJ791257 to FJ791273). In Mass cluster aminoacids identity range from 98% to 100%, suggesting vaccine virus detection, in this last case. Moreover, the verified identity between samples from this study and Mass group ranged 79% to 81%. Therefore the present study reinforces the emergence and circulation of news lineages of IBV in commercial Brazilian flocks, as well as the importance of consistent research and monitoring to better understand this phenomen and its consequences, aiming to improved control measures against the virus.

A bronquite Infecciosa das galinhas (BIG) é uma doença respiratória aguda e altamente contagiosa que acomete galinhas de diferentes idades. Foram utilizadas duas amostras do VBIG de problemas respiratórios e entéricos em frangos. As amostras foram classificadas como variantes do VBIG através da técnica de RT-PCR multiplex e sequenciamento parcial do gene S1. As amostras foram inoculadas em frangos de corte e aves SPF (specific pathogen free). As aves apresentaram sinais respiratórios 36 horas após inoculação independente da origem viral, entérica ou respiratória, sendo mais discretos nas aves SPF. As alterações macroscópicas mais evidentes foram congestão da mucosa traqueal, pulmão e rins. A análise histopatológica mostrou lesões semelhantes àquelas encontradas em outros sorotipos. A análise filogenética mostrou que as duas amostras eram similares e diferentes das amostras Massachusetts. Esses resultados sugerem que os isolados classificados como variantes apresentam potencial patogênico para aves. / Infectious bronchitis (IB) is an acute respiratory disease, highly contagious which affects chickens of different ages. This study was composed with two isolates obtained from broilers with respiratory and enteric problems. These isolates were classified as IBV variants by the multiplex RT-PCR and by sequencing of S1 gene. Isolates were inoculated in broilers and SPF birds. The birds showed respiratory signs 36 hours post inoculation, independently of the enteric or respiratory source. The respiratory signs were less evident on SPF birds. The histopathology analysis showed significant lesions on the trachea, lungs and kidneys. The phylogenetic analysis of S1 gene showed that both isolates were similar and different from Massachusetts strains. These results suggest that the isolates classified as variant have pathogenic potential for birds.

El objetivo del estudio era identificar las exposiciones ocupacionales relacionadas con asma en empleadas de limpieza doméstica. Un estudio poblacional transversal realizado en 4,521 mujeres mostró que las empleadas del hogar tenían un mayor riesgo de asma y bronquitis crónica que las mujeres que nunca habían trabajado en limpieza. Posteriormente, se realizo un estudio caso-control en empleadas del hogar que incluia 40 casos de asma y/o bronquitis crónica y 155 controles. Los casos estaban expuestos más frecuentemente a lejía y a fregar los platos y habían sufrido más accidentes de inhalación con productos de limpieza. Finalmente, en un estudio de panel en 43 empleadas del hogar con problemas respiratorios, se observó empeoramiento de los síntomas de las vías respiratorias inferiores los días de trabajo y los días expuestos a lejía, desengrasantes y/o ambientadores. Se concluye que las empleadas del hogar tienen un aumento en el riesgo de asma y posiblemente bronquitis crónica y que dicho riesgo está relacionado principalmente con exposiciones irritantes. / We aimed to investigate the relationship between occupational exposures and asthma in women employed in domestic cleaning. A population-based cross-sectional study among 4,521 women showed that domestic cleaners had an increased risk of asthma and chronic bronchitis symptoms as compared with those never employed in cleaning. Subsequently, a case-control study among domestic cleaning women was conducted including 40 cases of asthma and/or chronic bronchitis and 155 controls. Cases were more frequently exposed to bleach and washing dishes and had experienced more inhalation accidents involving cleaning products than controls. Finally, a panel study among 43 domestic cleaning women with respiratory symptoms showed aggravation of lower respiratory symptoms on working days and on days with exposure to bleach, degreasers and/or air-fresheners. In conclusion, women employed in domestic cleaning are at an increased risk of asthma and possibly chronic bronchitis, this risk being predominantly related to irritant exposures.

Σκοπός της παρούσας μελέτης ήταν να αξιολογηθεί το αγγειομετατρεπτικό ένζυμο στον ορό των ασθενών με πνευμονία, ως διαγνωστικός ή/και προγνωστικός δείκτης της νόσου και γενικά να μελετηθούν οι διάφοροι προγνωστικοί παράγοντες στις λοιμώξεις του κατώτερου αναπνευστικού συστήματος. / Objective: The aim of this study was to determine prognostic factors of outcome in patients with lower respiratory tract infections (LRTIs). LRTIs are an heterogeneous group of disorders, including acute bronchitis, pneumonia, superinfection of chronic bronchitis and flu. The recent publications of several prognostic factors of outcome address specific conditions such as pneumonia or bronchitis, while general practitioners cannot usually differentiate between these conditions in current practice. Methodology: A total of 616 patients with LRTIs were retrospectively reviewed with regard to epidemiological, clinical, laboratory and radiographic data. The prognostic analysis included an univariate as well as a multivariate approach, in order to identify parameters associated with death. Results: The parameters found to be significantly different between survivors and non survivors in the univariate analysis, were respiratory rate (p<0,01), oxygen partial pressure (PaO2) (p<0,001), heart rate (p<0,0003), systolic and diastolic blood pressure (p<0,047 and (p<0,022, respectively), platelet count (p<0,045), urea (p<0,002), creatinine Objective: The aim of this study was to determine prognostic factors of outcome in patients with lower respiratory tract infections (LRTIs). LRTIs are an heterogeneous group of disorders, including acute bronchitis, pneumonia, superinfection of chronic bronchitis and flu. The recent publications of several prognostic factors of outcome address specific conditions such as pneumonia or bronchitis, while general practitioners cannot usually differentiate between these conditions in current practice. Methodology: A total of 616 patients with LRTIs were retrospectively reviewed with regard to epidemiological, clinical, laboratory and radiographic data. The prognostic analysis included an univariate as well as a multivariate approach, in order to identify parameters associated with death. Results: The parameters found to be significantly different between survivors and non survivors in the univariate analysis, were respiratory rate (p<0,01), oxygen partial pressure (PaO2) (p<0,001), heart rate (p<0,0003), systolic and diastolic blood pressure (p<0,047 and (p<0,022, respectively), platelet count (p<0,045), urea (p<0,002), creatinine (p<0,002), previous admission in the hospital the last year (p<0,033), and cavitations in chest radiograph (p<0,047). In multivariate analysis, the only statistically significant risk factors were PaO2 (odds ratio (OR) =0,8574; 95% confidence interval (CI) 0,7499-0,9802 in non survivors compared to survivors) and heart rate (OR=1,063; 95% CI 1,0052-1,1241 in non survivors compared to survivors). Conclusions: LRTIs remain a widespread problem and have a significant impact on primary healthcare resources. The great variability seen in rates of hospital admission and lengths of stay in part reflects uncertainty among physicians in assessing the severity of the illness. According to our data, PaO2 and heart rate, were most closely associated with death in patients with LRTIs. These predictor variables are all explicitly defined and can be readily assessed at the time of patient presentation.

Aim. To assess associations between occupational air pollution and respiratory health, especially in miners. Background. Indications of associations between occupational exposure or social economic status and respiratory health have been found in several population-based studies. However, there have been few longitudinal studies of the putative correlations, the effects of environmental and genetic factors have seldom been simultaneously studied, and studies of miners have generated conflicting results. Material and methods. Population-based Obstructive Lung Disease in Northern Sweden (OLIN) cohorts surveyed in 1986, 1992 and 1996, and two industry-based materials, were used in cross-sectional and longitudinal studies. Inflammatory markers were compared in sputa from miners after a vacation of at least four weeks, after repeated occupational exposures for at least three months, and controls. The mortality from silicosis was studied in 7729 miners with at least 1 year of exposure. Multivariate analyses were used to adjust for confounders. Results. Up to about 30-40% (etiologic fraction) of incident symptoms in persons both with and without a family history of asthma (FHA) could be explained by exposure to occupational air pollution. Low socio-economic status (SES) was associated with impaired respiratory health. Population attributable risks for most examined disorders were about 10%. Current and ex-miners had increased prevalence of recurrent wheeze, longstanding cough, physician-diagnosed chronic bronchitis, and a trend for increased sputum production. For physician-diagnosed chronic bronchitis a multiplicative interaction was found between exposure and smoking habits. Ex-miners that had been exposed for on average 13 years and whose exposure had ceased 16 years before the study had an increased prevalence of physician-diagnosed chronic bronchitis and chronic productive cough and a trend to increased use of asthma medicines. Miners exposed underground for 18 years, on average, to diesel exhaust (with 0.28 mg/m3 nitrogen dioxide and 27 μg/m3 elemental carbon on average, EC) and particles (3.2 mg/m3 inhalable dust on average) had signs of higher inflammatory activity in their airways, i.e. significantly higher frequencies of macrophages, neutrophils, and total cells compared with referents. The activity in miners was similar after a vacation of at least four weeks and after repeated exposures for three months. There were 58 deaths from silicosis (underlying and contributing cause of death) and a clear dose-response relationship. The data indicated an increased risk of severe silicosis after long-term exposure to 0.1 mg/m3 respirable quartz, the current maximum allowable concentration (MAC) in Sweden and many other countries. Conclusion. Occupational exposure to dust, gases, and fumes impaired respiratory health, accounting for up to 30-40% of some respiratory symptoms in the general population. Low socio-economic status was associated with impaired respiratory health. The complex profiles of dust and diesel exhaust substances found in mines may cause inflammatory reactions in their lungs and persistent respiratory symptoms in occupationally exposed miners. Long-term exposure to quartz at the present MAC level may cause severe silicosis.

Vis daugiau epidemiologinių tyrimų atskleidžia neigiamą oro taršos įtaką žmonių sveikatai. Ypač oro taršos neigiamam poveikiui yra jautrūs maži vaikai. Todėl, siekiant nustatyti ryšį tarp oro taršos kietosiomis dalelėmis ir bronchito rizikos, atlikome oro kokybės ir epidemiologinį „atvejis – kontrolė“ tyrimą. Nustatėme, kad vidutinė sezoninė kietųjų dalelių koncentracija dviejuose mikrorajonuose svyravo nuo 20 µg/m3 iki 41 µg/m3, o vidutinė metinė - svyravo nuo 24 µg/m3 iki 33 µg/m3. Didžiausia vidutinė metinė koncentracija 2010 ir 2011 nustatyta Petrašiūnuose. Atliekant „atvejis – kontrolė” nustatėme, kad Petrašiūnuose iki penkerių metų amžiaus vaikų bronchito paplitimas yra didesnis - 69% visų tirtų vaikų, kai Dainavoje – tik 49 % visų tirtų vaikų. Kontroliuojant ryšį iškraipančius veiksnius, nustatėme, kad riziką susirgti bronchitu dididno suaugusiųjų rūkymas ir vitamino D trūkumas. Tyrimo analizė leido padaryti išvadą, kad vaikams, gyvenantiems ir lankantiems darželius Petrašiūnų mikrorajone, rizika susirgti bronchitu buvo 2,9 karto (PI 95 % 1,789 – 4,716) didesnė, nei vaikams, kurie gyveno ir lankė darželius Dainavos mikrorajone. Taip pat nustatyta, kad berniukams rizika susirgti bronchitu yra didesnė, nei mergaitėms. / There are plenty of epidemiological researches reveal that, exposure to air pollution is associated with numerous effects on human health. The association of PM 10 with the prevalence of bronchitis among till 5 years old children was examined in a cross-sectional study. We found out that, average seasonal pm 10 concentration varied from 20 µg/m3 till 41 µg/m3. And average pm 10 concentration and counted in every year varied from 24 µg/m3 till 33 µg/m3. The highest average yearly pm 10 concentration was determined in Petrašiūnai 2010 and 2011 years. Also we found out that, the prevalence of bronchitis between 5 years old children was higher in Petrašiūnai (69%). The prevalence of bronchitis in Dainava was 49 %. Controlling the factors perverting connection we found out that, smoking and indoor smoking also deficiency of D vitamin have the tendency to increase the risk of bronchitis. In conclusion, we found that, children who lived and used to go to kindergartens in Petrašiūnai the risk of the bronchitis was 2,9 (PI 95 % 1,789 – 4,716).

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

Orientador: Tereza Cristina Cardoso Silva / Banca: Roberto Gameiro de Carvalho / Banca: Andréa Fontes Garcia / Resumo: O Vírus da Bronquite Infecciosa, assim como outras doenças infecciosas, é um dos principais limitantes à produção de frango de corte. O coronavírus responsável por causar essa doença influencia na perda de desempenho das aves acometidas prejudicando o perfil financeiro do setor. Considerando o Brasil hoje, o segundo maior exportador mundial de carne de frango e esse coronavírus altamente contagioso por suas perdas em níveis financeiro e industrias, este trabalho objetivou avaliar a presença do vírus em uma região do noroeste paulista sem vacinação compulsória. Para investigar a presença de anticorpos contra o mesmo, foram coletados de 100 aviários 10 soros de cada, os animais eram alojados de forma aleatória em 2 regiões que formam um ângulo de 360º com a unidade de abate integradora parceira deste trabalho. Por fim, as amostras foram mensuradas através do teste de ELISA® indireto, que abordou o método estatístico X 2 . Os resultados indicaram que há circulação do vírus p<0.1, demonstrando uma necessidade em se adotar um novo protocolo de vacinação para a região. / Abstract: - Infectious Bronchitis Virus is one of the main limiting factors for the production of broiler chickens, and is still responsible for the loss of performance of these birds and even motivating high mortality rates. Considering Brazil today, the second largest exporter of poultry in the world and this highly contagious coronavirus, due to its losses to the financier of the industries, this work aimed to evaluate the presence of the virus in a region of the northwest of São Paulo without compulsory vaccination. Thus, to investigate the presence of antibodies against it, 10 sera of each 100 birds were randomly housed in 2 regions that form a 360 degree angle with the integrating slaughter unit partner of this work. Finally, the samples were measured through the indirect ELISA, which approached the chi - square statistical method. The results indicated that there is circulation of the virus p <0.1, demonstrating a need to adopt a new vaccination protocol for the region / Mestre

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-04-18T14:52:38Z No. of bitstreams: 1 texto completo.pdf: 2107997 bytes, checksum: 9af3c7a1788cd5f34e07226a97b0fc13 (MD5) / Made available in DSpace on 2016-04-18T14:52:38Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2107997 bytes, checksum: 9af3c7a1788cd5f34e07226a97b0fc13 (MD5) Previous issue date: 2015-07-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A criação de aves em sistemas industrializados vem adquirindo, mundialmente, características que envolvem uma elevada densidade animal, o que, consequentemente, leva ao surgimento de condições epidemiológicas capazes de predisporem ao aparecimento de problemas sanitários. Diante deste contexto, aumenta-se a preocupação com as doenças infecciosas, dentre elas, a Bronquite Infecciosa das Galinhas (BIG), cujo agente etiológico é o Infectious bronchitis virus (IBV). O presente estudo teve como objetivo reconstruir a epidemiologia molecular do IBV, por meio de análises filogenéticas e filogeográficas dos genes estruturais N e S1, para estudo da evolução viral. Estas informações são importantes para estabelecer um padrão de dispersão em um contexto histórico geográfico, entender eventos biológicos no passado relacionados à dinâmica populacional e ajudar no desenvolvimento de estratégias efetivas de controle do IBV. Para isso, foram montados dois bancos de dados com sequências moleculares completas e parciais dos genes N e S1 obtidos no GenBank. O primeiro banco de dados (IBV1) contemplou sequências completas de S1 (N=256) e N (N=154) e o segundo banco de dados (IBV2) foi montado com sequências parciais de S1 (N=390) e N (N=173). Importantes parâmetros para estudo da evolução viral foram analisados nesse trabalho para os genes S1 e N do IBV, incluindo estimativas de eventos de recombinação, taxa de mutação, pressão de seleção, dinâmica populacional e dispersão espacial. Os resultados apontam que, na ausência de uma elevada taxa de mutação e pelo fato da seleção purificadora ser a principal forma de seleção natural no IBV, o processo de recombinação tem um papel fundamental na evolução do IBV. As análises de dinâmica populacional sugerem que, até meados da década de 2000, os diferentes programas de vacinação, juntamente com os métodos de biosseguridade, foram eficazes para controlar o crescimento do tamanho efetivo populacional do IBV. Contudo, a partir de 2007, o aumento da população de variantes do IBV, pode indicar que os protocolos vacinais, usados no presente, não estão sendo mais eficazes. Os resultados das análises de dispersão viral do gene S1 e N foram analisados de forma conjunta, a fim de reconstruir um padrão de dispersão do IBV ao longo de sua história evolutiva. O ponto de origem de todas as cepas atuais do IBV foi a China que, após dispersão local, disseminou para os Estados Unidos e, por conseguinte, se dispersou para diferentes países e continentes até alcançar a ampla distribuição mundial encontrada nos dias atuais. Os principais centros de dispersão atuais do IBV foram a China, Estados Unidos, Brasil, Taiwan e Europa. / The intensification of poultry in industrial systems has acquired, worldwide, features that involve a high stock density, which, consequently, leads to the emergence of epidemiological conditions that may predispose to the appearance of health problems. Given this context, the concern with infectious diseases increases, among the diseases is the Avian Infectious Bronchitis (IB), whose etiologic agent is the Infectious bronchitis virus (IBV). This study aimed to reconstruct the molecular epidemiology of IBV through phylogenetic and phylogeographic analyzes of structural genes N and S1, to the study of viral evolution. These pieces of information are important to establish a pattern of dispersion in a geographical historical context, to understand biological events in the past related to population dynamics and to help develop effective strategies for control of IBV. To establish a better outlook for discussion of IBV molecular epidemiology, there were created two databases with complete and partial molecular sequences of genes N and S1 obtained from GenBank. The first database (IBV1) considered complete sequences of the S1 (N = 256) subunit and of the N (N = 154) gene of IBV. To increase the extension of countries from which sequences are available, a second database (IBV2) was created with partial sequences of the S1 (N = 390) gene and the N (N = 173) gene. Important parameters for the study of viral evolution were analyzed in this work for the S1 and N genes of the IBV, including estimates of recombination events, mutation rate, selection pressure, population dynamics and spatial dispersion. The results show that, in the absence of a high mutation rate and because of the purifying selection to be the main form of natural selection in IBV, the recombination process plays a key role in the evolution of IBV. The analysis of population dynamics suggest that, until the mid-2000s, the different vaccination programs, along with the biosecurity methods have been effective in controlling the growth of effective population size of the IBV. However, since 2007, the increase in the population of IBV variants may indicate that the vaccine protocols, used in the present, have not been effective anymore. The results of analyzes of the viral spread of the gene S1 and N were analyzed together, in order to reconstruct a pattern of the IBV dispersion along its evolutionary history. The point of origin of all current strains of IBV was China, which after local dispersion spread to the United States of America and thus dispersed to different countries and continents until reaching the worldwide distribution found today. The current main scattering centers of the IBV were China, the United States, Brazil, Taiwan and Europe.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2016-04-27T14:27:09Z No. of bitstreams: 1 texto completo.pdf: 1652814 bytes, checksum: eb04b97fc0b892ebed6c35181487174a (MD5) / Made available in DSpace on 2016-04-27T14:27:09Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1652814 bytes, checksum: eb04b97fc0b892ebed6c35181487174a (MD5) Previous issue date: 2015-08-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Infectious bronchitis virus (IBV) é uma das principais causas de perdas econômicas na indústria avícola, afetando galinhas de todas as idades, apesar das tentativas de controle por vacinação. Os objetivos deste estudo de três capítulos propôs-se: 1) analisar a composição genética das vacinas vivas H120 e Ma5 de IBV disponíveis comercialmente no Brasil, 2) promover a caracterização molecular de IBV acometendo um plantel de matrizes e, 3) investigar persistência viral nesse lote ao final do ciclo de produção e verificar a ocorrência de transmissão vertical. No capítulo 1 foi obtida a sequência completa do gene S1 das vacinas produzidas por diferentes laboratórios, sendo verificada que as vacinas H120 possuem subpopulações de IBV distintas, refletindo em até 14 diferenças na sequência de aminoácidos entre as vacinas. Na análise do cromatograma de S1 obtida da vacina Ma5 também foi detectado pico secundário, sugerindo a presença de subpopulação do vírus. Para abordar essa questão foi desenvolvido um sistema para identificar a população de espécies de RNA dessa vacina. Apesar de ser clonada foram identificadas pelo menos cinco subpopulações do vírus intra-vacina. Portanto, essa grande diversidade genética entre as vacinas poderia justificar os diferentes resultados da vacinação. No capítulo 2, a sequência parcial de S1 de IBV foi obtida diretamente de amostras clínicas. A vacina Ma5, previamente utilizada nesse lote, foi detectada na traqueia e no intestino delgado; enquanto subpopulação de IBV variante foi identificada em órgão específico das aves. Esse achado tem grande importância sob o ponto de vista aplicado porque ele ilustra o potencial repertório patogênico que a infecção por IBV de campo pode imputar sobre um lote de galinhas acometidas pela doença. Finalmente, no capítulo 3, diferentes órgãos dessas galinhas em final de produção e líquido cório-alantoide (LCA) de embriões vivos com 18 dias de incubação oriundos desse lote foram utilizados para a detecção e identificação de IBV. A vacina Ma5 foi detectada no intestino delgado, rins e oviduto das galinhas e no LCA de embriões. No entanto, nas tonsilas cecais foi detectado IBV com significativa diferença genética na comparação com a vacina Ma5 previamente utilizada e aqueles identificados nos diferentes órgãos das aves na época da doença. Esses achados sugerem que além da vacina, outras subpopulações de IBV podem persistir por longos períodos no hospedeiro e, pelo menos em galinhas em final de produção a vacina Ma5 pode ser transmitida verticalmente. / Infectious bronchitis virus (IBV) is a major cause of economic losses in the poultry industry, affecting chickens of all ages, despite attempts to control by vaccination. The objectives of this three-chapter study were: 1) analyze the genetic makeup of the 120 and Ma5 IBV vaccines strains available commercially in Brazil, 2) promote the molecular characterization of IBV affecting one broiler breeding flock and, 3) to investigate IBV persistence in this flock at the end of the production cycle and to verify the occurrence of vertical transmission. In chapter 1, the complete sequence of the S1 gene of vaccines produced by different laboratories was obtained and verified that the vaccines of the strain H120 have different subpopulations, resulting in up to 14 amino acid sequence substitutions among the vaccines. On the other hand, the analysis of Ma5 strain S1 gene an additional peak was detected suggesting the presence of subpopulation of the virus. To address this issue a system to identify the population of RNA species of the vaccine was developed. Despite being cloned, at least five subpopulations of genotypes were detected with in a Ma5 batch. Therefore, this great genetic diversity among the vaccines could justify the different vaccination reactions/results. In chapter 2, partial sequence of S1 of the IBV was obtained directly from clinical specimens. In alignment with the Ma5, which was previously used therein, the same was detected in the trachea and small intestine; while subpopulation of IBV variant was identified in specific organ of birds. This finding has great importance from the applied point of view because illustrates the potential pathogenic repertoire that infection by field IBV can charge on the same lot of chickens affected by the disease. Finally, in chapter 3, different organs of breeders at the end of production and allantoic fluid of embryos with 18 days of incubation deriving this flock were used for the detection and identification of IBV. The Ma5 vaccine was detected in small intestine, kidneys and oviduct of the chickens, and also in the allantoic fluid embryos. However, in the cecal tonsils, IBV was detected in significant genetic difference in comparison with the previously used Ma5 vaccine and those detected in different organs of the birds at the time of disease. These results suggest that in addition to vaccine, other (s) subpopulation (s) of IBV can persist for long periods in the lost least chickens at the end of production Ma5 vaccine can be transmitted vertically.