Campylobacter is considered a fragile microorganism ans sensitive to environmental conditions, but demostrate strategies to survive in unfavorable environmental conditions. This study evaluated the viability and production of transcipts of the genes sodB, p19 ciaB and dnaJ in strains ATCC 33291, NCTC 11351 and IAL 2383 stored in UHT milk and neopeptona + 12% glycerol,whether or not subject to the pre-treatment temperature of 4°C or 10°C for 30 minutes.Analyses were performed immediately after freezing in liquid nitrogen (day 0) and after maintenance for 30, 60 and 90 days at -20°C.The viability was evaluated by traditional method of cultivation and production of transcripts by RT-PCR technique. The quantification was only possible on the first day of analysis (day 0) and had a mean of 3.0x107UFC and in the remaining periods of storage strains showed confluent growth not allowing their enumeration. The set of results has shown that the UHT milk was the most appropriate for cryopreservation than the use of neopeptona +12% glycerol. The pretreatment at 4°C for 30 minutes favored the production of transcripts for ciaB and dnaJ genes. For the strains ATCC 33291 and NCTC 11351 was verified a possible interconnection of sodB genes and p19, however, this link was not observed for the strain IAL 2383, which also showed different behavior from other strains for viability in both cryoprotectants and production of transcripts. The results of this study show that when the maintenance of viability of the strains is essential, it is necessary to use different combinations of cryoprotectants / treatments to increase the chances of recovery and, when the primary purpose is the production of transcripts, the option to maintain the reliability of the results is the immediate extraction of DNA of isolated strains. / Campylobacter é considerado um microrganismo frágil e sensível às condições ambientais, mas que demonstram possuir estratégias para sobreviver em condições ambientais desfavoráveis. Este estudo avaliou a viabilidade e produção de transcritos dos genes sodB, p19, ciaB e dnaJ em cepas ATCC 33291, NCTC 11351 e IAL 2383 armazenadas em leite UHT integral e neopeptona + glicerol 12%, submetidas ou não a pré-tratamentos à temperatura de 4°C ou 10°C por 30 minutos. As análises foram realizadas imediatamente após o congelamento em nitrogênio líquido (dia 0) e após manutenção por 30, 60 e 90 dias a -20ºC. A viabilidade foi avaliada pelo método tradicional de cultivo e a produção de transcritos pela técnica do RTPCR. A quantificação só foi possível no primeiro dia de análise (dia 0) e apresentaram média de 3,0 x 107 UFC, sendo que nos demais períodos de armazenamento as cepas apresentaram crescimento confluente não permitindo sua enumeração. O conjunto de resultados permitiu verificar que o leite UHT integral foi mais adequado para a criopreservação que o uso da neopeptona + glicerol 12%. O pré-tratamento a 4ºC por 30 minutos favoreceu a produção de transcritos para os genes ciaB e dnaJ. Para as cepas ATCC 33291 e NCTC 11351 foi verificada uma possível interligação dos genes sodB e p19, entretanto, esta ligação não foi observada para a cepa IAL 2383, que também mostrou comportamento diferente das outras cepas quanto à viabilidade nos dois crioprotetores e produção de transcritos. Os resultados obtidos neste estudo permitem concluir que quando a manutenção da viabilidade das cepas é essencial, faz-se necessário o uso das diferentes combinações crioprotetor/tratamentos para aumentar as chances de recuperação e, quando o objetivo principal é a produção de transcritos, a opção para manter a fidedignidade dos resultados é a extração imediata do DNA das estirpes isoladas. / Mestre em Ciências Veterinárias

The objective of this study was to evaluate the viability of Campylobacter jejuni and quantify indicator microorganisms (mesophilic bacteria, total coliforms and E. coli) in initial and final broiler feed artificially contaminated with 103 and 105 CFU of C. jejuni per gram of ration, kept at two different temperatures of storage (25 and 370C) and analyzed on four different storage periods 0, 24, 72 and 120 hours. C. jejuni survived throughout the study period and multiplied when inoculated with 103UFC, with the highest counts observed when the feed was kept at a temperature of 370C. Overall, there was a multiplication of mesophilic microorganisms, but the amount of coliforms didn´t increase with time. This work shows that the importance of feed in the epidemiology of C. jejuni in broilers should be better assessed and instigates other studies to verify the possible symbiotic relationship between C. jejuni and mesophilic. / O objetivo desse estudo foi avaliar a viabilidade de Campylobacter jejuni e quantificar microrganismos indicadores (bactérias mesófilas, coliformes totais e E. coli) em rações inicial e final de frangos de corte artificialmente contaminadas com 103 e 105 UFC de C. jejuni por grama de ração, mantidas em duas diferentes temperaturas de armazenamento (25 e 370C) e analisadas em quatro períodos de armazenamento distintos 0, 24, 72 e 120 horas. A C. jejuni sobreviveu durante todo o período avaliado e se multiplicou quando inoculada 103 UFC, sendo observadas as maiores contagens quando a ração foi mantida na temperatura de 370C. Houve multiplicação de microrganismos mesófilos, mas a quantidade de coliformes não aumentou com o tempo. Este trabalho alerta para a necessidade de melhores investigações sobre a importância da ração na epidemiologia da C. jejuni em frangos de corte e a relação mesófilo e Campylobacter. / Mestre em Ciências Veterinárias

Membros termofílicos do gênero Campylobacter são reconhecidos como importantes enteropatógenos para o ser humano e animais. A grande diversidade ecológica destes microorganismos em diferentes habitats tais como: água, animais e alimentos predispõem ao aparecimento de novos fatores de virulência. Este trabalho teve por objetivo detectar os genes codificantes da Toxina Distensiva Citoletal (CDT) por meio da técnica de PCR, pesquisar a atividade de hemolisinas e a influência de soluções quelantes e de íons nesta atividade. Foram utilizadas 45 amostras de C. jejuni de origem avícolas para pesquisa de atividade hemolítica, cultivadas em Caldo Triptona de Soja (TSB). Após o crescimento bacteriano, as amostras foram semeadas em Ágar tríptico de soja (TSA) contendo 5% de sangue de ovino, equino e bovino, sendo cada sangue testado isoladamente. Para verificar a influência de agentes quelantes e solução de íons na atividade hemolítica, as amostras de C. jejuni foram cultivadas em TSB contendo separadamente os quelantes EDTA, ácido acético, soluções de íons CaCl2 , MgCl2 e FeCl3, em atmosfera de microaerofilia. Quanto à atividade de hemolisina de Campylobacter jejuni em placas de TSA – sangue, foi possível observar que houve hemólises em 48,89% das amostras quando utilizado sangue eqüino, em 40% em sangue de bovino e em 31,11% quando de ovino. Quanto à influência de agentes quelantes e íons em caldo TSB na atividade de hemolisinas em amostras de Campylobacter jejuni semeadas em placas de TSA – sangue ovino, foi observada atividade hemolítica em 26,67% quando utilizado CaCl2, 15,55% (FeCl3), 22,22% (EDTA), 11,11% (MgCl2) e apenas 2,22% (ácido acético). No tocante à atividade hemolítica, o TSA - sangue bovino apresentou 15,55% (CaCl2), 24,44% (FeCl3), 26,26% (EDTA), 20% (MgCl2) e 11,11% (ácido acético). A atividade hemolítica para o sangue equino foi de 24,44% (CaCl2), 22,22% (FeCl3), 28,89% (EDTA), 28,89% (MgCl2) e 8,89% (ácido acético). Para detecção dos genes cdtA, cdtB e cdtC através da técnica da Reação da Polimerase em Cadeia (PCR), foram utilizadas 119 amostras de C. jejuni de origem avícolas. Foi possível observar que 38% possuíam os três genes, e foram identificados somente os genes cdtA e cdtC em 19% do total de amostras, sendo que o gene cdtB foi encontrado em 14%, o gene cdtC foi observado em 12%, os genes cdtA e cdtB em somente 1%, os genes cdtB e cdtC em 1% e para cdtA em 1%. Observou-se que os resultados são dignos de atenção, pois demonstraram em amostras avícolas a presença de estirpes de C. jejuni com potencial virulento. A atividade hemolítica apresentou significativo aumento quando utilizado sangue de origem equina. A mesma foi diminuída quando utilizados agentes quelantes ou íons, nos três tipos de sangue. / Thermophilic members of the Campylobacter genus are recognized as important enteropathogenics for humans and also for other animals. The great diversity of ecological habitats in different organisms such as water, food, and animals may promote new virulence factors. This study aimed at detecting the distending cytolethal toxin (CDT) encoding genes by PCR, studying the activity of hemolysin and also the influence of chelation solutions and ions. A total of 45 samples of C. jejuni from poultry origin, grown in Tryptone Soy Broth (TSB) were used for investigating hemolytic activity. After bacterial growth, samples were plated on Tryptic Soy Agar (TSA) containing 5% sheep, equine or bovine blood, being each blood tested individually. In order to check the influence of chelation agents and ions solution on the hemolytic activity, samples of C. jejuni strains were grown in TSB containing chelation agents individually: EDTA, acetic acid, CaCl2 ion, MgCl2 and FeCl3 solutions, all in microaerophilic atmosphere. Regarding the detection of Campylobacter jejuni hemolysin activity on TSA plates, blood hemolysis were observed in 48.89 % of samples when equine blood was used; in 40% of samples when bovine blood was used and in 31.11 % when the blood used was of sheep origin. The influence of ions and chelation agents in hemolysin activity in TSB when Campylobacter jejuni was plated on TSA with sheep blood can be described as: hemolytic activity was observed at 26.67% of samples when CaCl2 was used, at 15.55 % for FeCl3, 22 22 % for EDTA, 11.11 % for MgCl2 and only 2.22% when acetic acid was used. The hemolytic activity detected when bovine blood - TSA was used indicated 15.55% for CaCl2, 24.44% for FeCl3, 26.26 % for EDTA, 20 % for MgCl2 and 11.11% for acetic acid. In terms of the hemolytic activity when equine blood was used, the results indicated 24.44% for CaCl2, 22.22 % for FeCl3, 28.89 % for EDTA, 28.89 % for MgCl2 and 8.89% for acetic acid. Finally, regarding the detection of cdtA, cdtB and cdtC through PCR, 119 samples of C. jejuni from poultry origin were used. The results indicated that all three genes were present in 38 % of the samples, whereas only two genes were identified in 19 % of samples, while the cdtB gene was singly found in 14%, the cdtC gene was independently observed in 12%, cdtA and cdtB genes together were found in 1% of the samples; the cdtB and cdtC genes associated were detected in 1%, while cdtA alone answered for 1% of detections. The results also showed the presence of C. jejuni strains with virulence potential. The hemolytic activity increased significantly when blood of equine origin was used, and that this activity was reduced when ions or chelating agents were used in combination with the three types of blood cells.

Campylobacter jejuni is the main cause of bacterial diarrhoeal illness in developed countries, with ~7000 cases being reported each year in Sweden. C. jejuni has received growing attention since it’s recognition as a human pathogen in the 1970s, but its epidemiology is complex and much still remains unknown. There are several potential reservoirs for C. jejuni, including environmental sources as water and soil, wild and domesticated animals, particularly poultry, but also other livestock and pets. In this study 348 Swedish C. jejuni isolates from the year 2000 from humans (n = 164) and broilers (n = 184) were characterized with multilocus sequence typing (MLST) with the aim of comparing the population structures and diversity of C. jejuni between isolates from the two hosts. MLST is a method for characterization of bacterial isolates that indexes the variation in DNA sequence of multiple protein encoding housekeeping genes. A secondary aim in this study was to compare populations of C. jejuni from 11 subgroups of isolates based on location of the sampling. The overlap between the populations was analyzed numerically based on genotypes detected and with analysis of phylogeny, gene flow and molecular variation. It was shown that the population structure of C. jejuni isolates from broilers and humans show a high degree of similarity, supporting broilers as an important source of human infection. However, even though the population structure of human and broiler C. jejuni were almost genetically indistinguishable other sources of C. jejuni infections in humans cannot be ruled out since the same genotypes can be found in other sources as well. Analysis of the 11 subgroups suggested that there may be a difference in populations infecting humans in different Swedish regions, and between populations of C. jejuni in broilers from different slaughterhouses. But this could be a result of chance since most of the subgroups were small. Future studies to improve the understanding of C. jejuni epidemiology, for which MLST has proven itself as a valid method, is important to develop control strategies to prevent infection with this common cause of diarrhoeal illness.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-05-05T15:00:33Z No. of bitstreams: 1 Junior Mario Baltazar de Oliveira.pdf: 1499654 bytes, checksum: 6880a06cd3c2f0f28c7d609803cb7e9e (MD5) / Made available in DSpace on 2017-05-05T15:00:33Z (GMT). No. of bitstreams: 1 Junior Mario Baltazar de Oliveira.pdf: 1499654 bytes, checksum: 6880a06cd3c2f0f28c7d609803cb7e9e (MD5) Previous issue date: 2014-08-08 / The objective of this study was to perform an epidemiological analysis of Campylobacter fetus subsp. venerealis and Tritrichomonas foetus infection in cattle from state of Pernambuco, Brazil. For this, 383 samples of cervical-vaginal mucus of cows from 21 properties distributed in the 19 counties that make up the microregion of Garanhuns and 105 samples of preputial smegma of males in the reproductive age, coming from 32 properties and four slaughterhouses were collected from state Pernambuco. The samples had their genomic materials extracted and subjected to polymerase chain reaction for diagnosis. To analyze the risk factors applied an investigative questionnaire on the hygienic, sanitary and reproductive management. The risk factors identified in this study was to bovine genital campylobacteriosis in female herds above 100 animals (OR=7.2, C.I. 1.3 to 38.4%, p=0.020) and bovine trichomoniasis was the use of natural mating (OR=2.4, C.I. 1.1 to 5.9%, p=0.041). In males, there was a frequency of 6.6% (2.7%-13.2%, 95% C.I.) for T. fetus and no sample was positive for C. fetus subsp. venerealis. Regarding the number of outbreaks, 21.8% of farms had animals positive for T. foetus. None analyzed variables was associated with infection. Regarding the samples from slaughterhouses, none was positive. It is concluded that infection by C. fetus subsp. venerealis and T. foetus are present in cattle in the state of Pernambuco and suggest that control measures such as diagnosis and prophylaxis, and sexual segregation and rest of infected females, using a program of artificial insemination with strict health care, elimination of infected bulls and replacement for young animals are implemented to prevent the spread of agents in herds. / Objetivou-se com este trabalho realizar uma análise epidemiológica da infecção por Campylobacter. fetus subsp. venerealis e Tritrichomonas foetus em bovinos do estado de Pernambuco, Brasil. Para isso, foram colhidas 383 amostras de muco cérvico-vaginal de vacas procedentes de 21 propriedades distribuídas nos 19 municípios que compõem a microrregião de Garanhuns e 105 amostras de esmegma prepucial de machos em idade reprodutiva, procedentes de 32 propriedades e quatro matadouros do estado de Pernambuco. As amostras tiveram seu material genômico extraído e submetido à reação em cadeia da polimerase para o diagnóstico. Para análise de fatores de risco aplicou-se um questionário investigativo com perguntas referentes ao manejo higiênico-sanitário e reprodutivo. Nas fêmeas, observou-se uma prevalência de 1,8% (0,8% - 3,9%; I.C. 95%) e 33,4% (28,7% - 38,4%; I.C. 95%;) para Campylobacter fetus subsp. venerealis e Tritrichomonas foetus, respectivamente. Em relação ao número de focos observou-se que 28,6% das propriedades apresentaram pelo menos um animal positivo para C. fetus subsp. venerealis e 90,5% para T. foetus. Os fatores de risco identificados neste estudo para campilobacteriose genital bovina em fêmeas foi rebanhos acima de 100 animais (OR=7,2; I.C. 1,3 - 38,4%; p=0,020) e para tricomonose bovina foi a utilização da monta natural (OR=2,4; I.C. 1,1 - 5,9%; p=0,041). Nos machos, observou-se uma frequência de 6,6% (2,7% - 13,2%; I.C. 95%) para T. foetus e nenhuma amostra foi positiva para C. fetus subsp. venerealis. Em relação ao número de focos, 21,8% das propriedades apresentaram animais positivos para T. foetus. Nenhuma das variáveis analisadas apresentou associação com a infecção. Quanto às amostras dos matadouros, nenhuma foi positiva. Conclui-se que as infecções por C. fetus subsp. venerealis e T. foetus estão presentes nos rebanhos bovinos do estado de Pernambuco e sugere-se que medidas de controle e profilaxia como o diagnóstico, separação e repouso sexual das fêmeas infectadas, utilização de um programa de inseminação artificial com cuidados sanitários rigorosos, descarte dos touros infectados e reposição por animais jovens devem ser implementadas a fim de evitar a disseminação do agente nos rebanhos.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-06-15T12:48:17Z No. of bitstreams: 1 Ruy Brayner de Oliveira Filho.pdf: 2028711 bytes, checksum: c66c5e9d041a3c1b673438d6c412bde8 (MD5) / Made available in DSpace on 2018-06-15T12:48:17Z (GMT). No. of bitstreams: 1 Ruy Brayner de Oliveira Filho.pdf: 2028711 bytes, checksum: c66c5e9d041a3c1b673438d6c412bde8 (MD5) Previous issue date: 2017-10-16 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The objective of this study was to determine the epidemiological situation of infection by Tritrichomonas foetus and Campylobacter fetus subsp. venerealis in cattle at Brejo Paraibano microregion, Northeastern Brazil, identifying the possible risk factors associated with T. foetus infection. For the study of T. foetus, 349 samples of cervico-vaginal mucus and smegma were collected in beef and dairy cattle (290 females and 59 males) in 31 farms and for C. fetus subsp. venerealis, 273 samples of cervico-vaginal mucus from dairy cows from 19 farms were collected. Polymerase Chain Reaction was used to identify the DNA of the agents and culture with Modified Diamond medium for isolation of T. foetus. For analysis of risk factors associated with Tritrichomonas foetus infection in bovine species, univariate analysis of the variables of interest was performed by the Pearson chi-squared test, or Fisher's exact test, when necessary. Subsequently, logistic regression was performed considering PCR (positive or negative) as the dependent variable for trichomoniasis. Thematic maps were prepared with prevalence distributions in the studied area. The prevalence of C. fetus subsp. venerealis infection in cows was 7.7% (21/273) (CI 95% 4.8% – 11.5%), and 31.6% (6/19) of the farms showed at least one positive animal. The prevalence of T. foetus infection was 3.7% (13/349) (CI 95%, 2.1 - 6.4%). Regarding the gender, a prevalence of T. foetus infection of 4.5% (females) and 0.0% (males) was observed. The percentage of farms that had at least one positive animal for T. foetus was 19.3% (6/31). In culture, no samples were positive for T. foetus. The risk factor associated with T. foetus infection identified in this study was contact of females with bulls of other farms (OR 5.9; CI 1.5 - 22.4). This is the first report of C. fetus subsp. venerealis infection in dairy cows in this region of Brazil and the first in Brejo Paraibano microregion that analyzed T. foetus infection in cattle. To reduce risk of infection, it is recommended to adopt an artificial insemination program on the farms with negative bull semen, as well as a vaccination program against Bovine Genital Campylobacteriosis to stimulate immunity to reduce the occurrence of infection and possible reproductive problems. Contact of females with males of other farms should be avoided, especially when the health status of these bulls is not known regarding these two infections. / Objetivou-se com este estudo determinar a situação epidemiológica das infecções por Tritrichomonas foetus e Campylobacter fetus subsp. venerealis em bovinos na microrregião do Brejo Paraibano, região Nordeste do Brasil, identificando os possíveis fatores de risco associados à infecção por T. foetus. Para pesquisa de T. foetus foram coletadas 349 amostras de muco cérvico vaginal e esmegma em bovinos de corte e leite (290 fêmeas e 59 machos) em 31 propriedades e para pesquisa de C. fetus subsp. venerealis foram coletadas 273 amostras de muco cérvico vaginal de vacas leiteiras procedentes de 19 propriedades. Para a pesquisa do DNA dos agentes utilizou-se a Reação em Cadeia da Polimerase e cultivo com meio Diamond Modificado para isolamento de T. foetus. Para análise dos fatores de risco associados à infecção por Tritrichomonas foetus na espécie bovina, foi realizada uma análise univariada das variáveis de interesse pelo teste qui-quadrado de Pearson, ou Exato de Fisher, quando necessário. Posteriormente foi realizada uma regressão logística considerando como variável dependente para Tricomonose a PCR (positivo ou negativo). Foram elaborados mapas temáticos com as distribuições das prevalências na área estudada. A prevalência da infecção por C. fetus subsp. venerealis em vacas foi 7,7% (21/273) (I.C. 95%; 4,8 - 11,5%) e 31,6% (6/19) das propriedades apresentaram ao menos um animal positivo. A prevalência da infecção por T. foetus foi 3,7% (13/349) (I.C. 95%; 2,1 – 6,4%). Em relação ao sexo, observou-se uma prevalência da infecção por T. foetus de 4,5% (fêmeas) e 0,0% (machos). A porcentagem de propriedades que apresentaram ao menos um animal positivo para T. foetus foi de 19,3% (6/31). No cultivo, nenhuma amostra foi positiva para T. foetus. O fator de risco associado à infecção por T. foetus identificado neste estudo foi contato de fêmeas com touros de outras propriedades (OR 5,9; I.C. 1,5 – 22,4). Este é o primeiro relato da infecção por C. fetus subsp. venerealis em vacas leiteiras nesta região do Brasil e o primeiro na microrregião do Brejo Paraibano a analisar a infecção por T. foetus em bovinos. Para diminuir os riscos de infecção, recomenda-se a adoção de um programa de inseminação artificial nas propriedades com sêmen de touros negativos, bem como um programa de vacinação contra a Campilobacteriose Genital Bovina para estimular a imunidade, com o intuito de reduzir a ocorrência da infecção e possíveis problemas reprodutivos. O contato das fêmeas com machos de outras propriedades deve ser evitado, principalmente quando não se conhece o status sanitário desses touros em relação a estas duas infecções.

Memoria para optar al Titulo Profesional de Médico Veterinario / El objetivo del presente estudio fue aislar, cuantificar y caracterizar molecularmente a Campylobacter jejuni (C. jejuni) proveniente de muestras de canales obtenidas en la etapa de eviscerado y enfriado en dos plantas faenadoras de pollos broiler de la Región Metropolitana. Además se obtuvo los datos del enfriador de agua de las canales (“chiller”) en ambas plantas para establecer las diferencias. Las cepas de C. jejuni fueron aisladas en medios de cultivo selectivos, posteriormente identificadas por pruebas bioquímicas y caracterizadas a través de “Electroforesis en Gel de Campo Pulsado” (PFGE) usando dos enzimas de restricción, SmaI y KpnI. Los resultados mostraron que, C. jejuni se aisló en 166 de las 259 muestras analizadas (64%). En la planta A se obtuvo un total de 82% (107/130) muestras positivas y en la planta B 46% (59/129). Al analizar la contaminación por etapa de proceso se observó mayor porcentaje de ocurrencia en la etapa de eviscerado 71% (97/136) que enfriado 56% (69/123), mientras que al analizar los datos por planta y etapa se obtuvo que en la planta A la etapa de eviscerado tuvo un 89% y la etapa de enfriado un 74% de ocurrencia para C. jejuni. Comparativamente, la contaminación con Campylobacter en la planta B fue menor en ambas etapas con un 53% de ocurrencia en el eviscerado y un 37% en el enfriado. Los resultados de la caracterización molecular de C. jejuni mostraron 13 patrones distintos de macrorrestricción al usar la enzima SmaI y 12 al aplicar KpnI. En ambos casos se obtuvo 6 patrones comunes, siendo los restantes patrones únicos (6 y 7 respectivamente). Los mismos patrones se observaron tanto en la etapa de eviscerado como de enfriado. Los controles de temperatura en el “chiller” de las plantas A y B fueron en promedio de 1,56ºC y 0,59ºC respectivamente. La planta B presenta temperaturas significativamente menores (p=0,0024). La concentración de cloro del agua del “chiller” medida en la planta A fue de 0,58 ppm y en la planta B de 0,53 ppm. Las diferencias observadas no fueron significativas (p=0,4315). Solo ocurrió una disminución estadísticamente significativa de los porcentajes de ocurrencia desde la etapa de eviscerado a enfriado por parte de la Planta A. Sin embargo, la ocurrencia en la planta A siempre fue mayor que la planta B. Los patrones de macrorrestricción observados fueron específicos para cada una de las plantas y según el día de muestreo, no así para las etapas. Estos resultados, inducen a pensar, que la mayor contaminación de las canales con C. jejuni corresponde a la proveniente de la crianza y no se genera al interior de la planta faenadora de aves

Philosophiae Doctor - PhD / Species of Campylobacter, Arcobacter and Helicobacter have been associated with various diseases in humans and animals; and chickens have been identified as a reservoir of these microorganisms. Two published techniques and a new technique, developed in this dissertation, were evaluated to test its efficiency in removing PCR inhibitors from chicken samples. All of the techniques were based on agarose/DNA slants and were evaluated using multiplex PCR and an Internal Amplification Control. The new technique was found to be most effective and consequently used further in the study. A novel study was done to evaluate the survival of Campylobacter, Arcobacter and Helicobacter strains in chicken blood at -20, 4, 37 and 42ºC as well as at ambient room temperature (±222ºC). It was found that all strains could survive at all temperatures, albeit at different duration times. Most notably, an A. butzleri strain was able to survive at 4ºC for up to 297 days. / South Africa

The major outer membrane protein, MOMP, is the main protein in the outer membrane of pathogenic Campylobacter bacteria. Infection with Campylobacter is the principle cause of severe enteritis and untreated may result in non-trauma related paralysis. Studies have shown, that MOMP can act as antigen and thus has the potential to provide protection by induced humoral immunity. In our study, we expressed recombinant MOMP in Escherichia1coli, developed an alternative method to extract the outer membrane protein from its lipid environment and solved and characterised its crystal structure. The information acquired through these structural studies sheds new light on the structural characteristics of this important membrane protein. The West-African Lassa virus can cause deadly haemorrhagic fever. Lassa virus only possesses five proteins, which are synergistically responsible for the virus' life cycle, and virulence. The way in which the individual proteins act with one another and with host cell proteins is not fully understood. The polymerase L is the largest of the five proteins and has multiple functions. In this study, we first divided the L protein into different domains and tested their recombinant expression in Escherichia1coli. For first time, we solved the crystal structure of the putative endonuclease domain of Lassa virus and validated its endonucleolytic function by means of RNA digestion assays and alanine point mutations.

Campylobacter jejuni is a major cause of bacterial gastroenteritis in the developed world; however, many aspects of its biology remain poorly understood, including its colonization of the mucus layer lining the gastrointestinal tract. In this study, we utilized microarray transposon tracking to compile a list of 195 genes essential for the growth of C. jejuni in vitro under microaerophilic conditions. Then we characterized C. jejuni growing in an extracted intestinal mucus medium. We found that C. jejuni will grow efficiently in a medium comprised of either chick and piglet intestinal mucus, and that these media have a dramatic impact on its transcriptome. Within the genes identified as differentially expressed during growth in a mucus medium, we identified a single operon, (cj0481-cj0490), which we have subsequently characterized as being responsible for both the uptake and metabolism of L-fucose. This represents the first observation of carbohydrate metabolism by the otherwise asaccharolytic C. jejuni. We further found that the inability to utilize L-fucose puts C. jejuni at a competitive disadvantage when colonizing the piglet intestine, but not the chick cecum. Finally, we examined C. jejuni’s ability to utilize mucins as a carbon source while growing within the mucus layer. We found that despite mucins being a major source of L-fucose and amino acids within the intestine, C. jejuni has a minimal ability to degrade and utilize mucins on its own. However, close proximity to mucolytic bacteria within the microbiota of the intestine, allows for increased C. jejuni growth. Together, this paints the picture of an organism that is well adapted to survival within the mucus lining of the intestine and establishing itself as part of the intestinal microbiota.