Orientador: Ihiel Schwartz Schneider / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-16T18:03:07Z (GMT). No. of bitstreams: 1 Serrano_AntoniodeMelo_D.pdf: 9163332 bytes, checksum: a97cf7421bdaa308a9af5d09267de262 (MD5) Previous issue date: 1976 / Resumo: Para se pesquisar a ocorrência de C. perfringens em produtos alimentares vendidos em Campinas, são Paulo, foram examinadas 50 amostras de carne molda de bovino, obtidas de máquinas moedoras de açougues, 50 amostras de carne de sulno, em pedaços, 35 amostras de corvina, 50 de frango já cortado em pedaços, amostras de lingüiça fresca, 31 de salsicha e 31 de coxinha de galinha, todas obtidas em diversos retalhistas, com exceção da corvina, colhida em atacadista. As amostras, após homogeneização, foram isoladas em placas com ágar-sangue e a confirmação do microrganismo foi feita no meio de WILLIS & BOBBS (1958). Para a pesquisa do f. perfringens em carne bovina, frango e corvina, foram usados três procedimentos: num, o homogoneizado foi semeado diretamente em ágar-sangue; noutro, a mesma semeadura foi feita depois de um aquecimento a 809C, por 10 min; e, num terceiro, o homogeneizado foi inoculado em caldo de carne cozida, aquecido em banho-maria fervente, por 60 min.,incubado de pois inoculado em ágar~sangue. A freqüência média de amostras positivas de carne bovina, nesses meios, foi de 10%, 2% e 4%, respetivamente; de carne suína, foi de 20%, 0% e 6%; 15%, 0% e 2%, para frango; e 4%, 0% e 0%, para corvina. Para a mesma pesquisa em salsicha, lingüiça e coxinha, foram usados apenas dois procedimentos: num, homogeneizados idênticos de salsichas foram inoculados diretamente em placas; e, noutro, enriqueciam-se primeiro os homogeneizados em caldo de carne depois inoculava-se esta em ágar-sangue. A freqüência de cozida e amostras positivas foi de 3% e 6%, respectivamente. Idênticos procedimentos em lingüiça evidenciaram 6 e 60%; e 3% e 6%, em coxinhas. No exame de 120 estufas e posteriormente de 118, que mantinham produtos para pronto consumo, encontramos, respectivamente, 38,6% e 49,5% com temperaturas entre 309 e 489C, condição esta favorável ao desenvolvimento de f.. perfringens. Tendo ocorrido uma intoxicação alimentar num refeitório, foi distribuldo um questionário a parte de 2.016 pessoas que tomaram a refeição. O inquérito revelou que 88,2% das pessoas tiveram diarréia; 74,2%, dores abdominais; 16,1%, tonturas; 14%, prostração; 9,7%,náuseas; 8,6%, vômitos; 6,5%, febre. A mediana do tempo de incubação foi de 13 horas. A duração dos sintomas foi de menos de 24 horas, em quase todos os doentes. A contagem de C. perfringens nas fezes dos doentes foi maior do que a das pessoas normais. O alimento mais suspeito de ter causado a intoxicação foi uma maionese, cujos principais componentes eram corvina e batata. Em face das dificuldades na evidenciação da lecitinase, através dos processos até hoje descritos, procuramos obter um novo meio. No presente estudo, foram comparadas quatro culturas de C. perfringens: no meio de WILLIS & HOBBS (1958); no mesmo, modificado por HALL etalo (1969); e no meio de WILLIS & HOBBS, por nós modificado. Só neste último as quatro culturas mostraram a reação de lecitinase, de forma clara, indubitável e em apenas 24 horas / Abstract: Not informed. / Doutorado / Doutor em Engenharia de Alimentos

No description available.

No description available.

Thesis (Ph. D.)--University of Missouri--Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 148-155). Also available on the Internet.

Thesis (Ph.D.)--Indiana University, 2008. / Title from screen (viewed on June 2, 2009). Department of Pathology & Laboratory Medicine, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Stephen D. Allen. Includes vita. Includes bibliographical references (leaves 192-215).

Thesis (M.S.)--University of Wisconsin--Madison, 1932. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf [29]).

A method for the production of a hot hemolysin by CI. perfringens in a chemically defined medium is described. A factor essential for the production of lecithinase (alpha toxin ) has been partially purified from dried meat. It is suggested that this toxigenic factor is a protein derivative. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

Clostridium perfringens is a Gram-positive anaerobe capable of causing disease in humans and many animals. C. perfringens is able to move across surfaces in a manner that is dependent on growth and type IV pili. Type IV pili are filaments that can be extended away from the cell by rapid polymerization, and retracted by depolymerization. Furthering the understanding of the initial and final energetic states of the pilins will reveal insights into possible mechanisms of type IV pilus assembly. Toward that end, a pilin was purified from the Gram-negative pathogen Pseudomonas aeruginosa and incorporated into an artificial membrane. The pilin was probed by a solid state nuclear magnetic resonance (ssNMR) technique that can determine the angle and depth of insertion of a helical peptide, as well as fluorescent and electron microscopy. All type IV pilus systems involve the action of an assembly ATPase to provide energy to polymerize the pilus. One proposed mechanism involves two primary proteins: an ATPase and an integral membrane core protein (IMCP). Other type IV pilus proteins are thought to play supportive roles in aiding the traversal of the cell envelope. In order to evaluate this model, the assembly ATPase PilB2 and IMCP PilC2 from C. perfringens were purified and examined for interactions. The evidence presented here suggest that PilB2 and PilC2 do not interact directly, and cannot function as a core assembly apparatus. The carbonic anhydrase (Cpb) from C. perfringens strain 13 was characterized both biochemically and physiologically. Cpb belongs to the type I subclass of the β class and is the first β class enzyme investigated from a strictly anaerobic bacteria. Kinetic analyses revealed a two-step, pingpong, zinc-hydroxide mechanism of catalysis. Analyses of a cpb deletion mutant of C. perfringens strain HN13 showed that Cpb is strictly required for growth when cultured in semi-defined medium and an atmosphere without CO₂. The grew well in nutrient-rich media with or without CO₂ in the atmosphere, although elimination of glucose resulted in decreased production of acetate, propionate, and butyrate. The results suggest a role for Cpb in anaplerotic CO₂ fixation reactions by supplying bicarbonate to carboxylases. / Ph. D.

Clostridium difficile and Clostridium perfringens are among the most commonagents of enteric disease in both humans and domestic animals. The former continues to increase in prevalence and diseases caused by the latter persist. Infection with a recently emergedhypervirulent strain (NAP1/027/III) of C. difficile is increasingly common andserious sequelae and fatalities are much more common in these patients. In neonatalpiglets, C. difficile infection (CDI) has become a common occurrence. Historically,isolation of C. perfringens type A from patients with enteric disease has been consideredinconsequential due to its presence in the normal intestine and to the mild nature ofdisease syndromes such as porcine enteritis. However, both CDI and type A diseasecause losses to the swine industry and pigs have been implicated as a possible source ofC. difficile for infection in humans. We investigated the epidemiology and pathogenesisof porcine CDI, and immunity against porcine CDI and type A enteritis. The occurrenceof CDI in integrated swine production facilities was most common in neonatal pigs.Infection in sows was rare, and finisher pigs were culture negative. All C. difficile strainswere ribotype 078. Hypervirulent strain NAP1/027/TTIII was more virulent in neonatalpigs than both a historic human historic human strain and a porcine strain with toxinproducing potential similar to ribotype 027 strains. Inoculation of anti-microbial-treatedadolescent pigs with NAP1/027/III did not cause disease. Ingra-gastric inoculation ofpigs with purified TcdA resulted in severe small intestine damage which isuncharacteristic of natural disease; effects of TcdB were minimal. Passive immunizationof piglets against C. difficile TcdA or C. perfringens type A alpha (CPA) and beta 2(CPB2) toxins did not prevent disease.

La enterotoxemia, causada por el Clostridium perfringens, es la enfermedad infecciosa más importante que afecta a las alpacas, debido a que ocasiona elevadas tasas de mortalidad neonatal de hasta 70%. Recientes estudios han sugerido la participación de la Cp-PLC (C. perfringens fosfolipasa C) como factor de virulencia responsable del cuadro enterotoxemico en alpacas y otras especies domesticas. El presente estudio evaluó las características toxigénicas de la Cp-PLC y de sobrenadantes de diferentes aislados de C. perfringens obtenidos de casos de enterotoxemia en alpacas relacionándolos con sus niveles de producción de Cp-PLC. El protocolo de purificación de Cp-PLC mostró ser exitoso, mostrando su comportamiento como una enterotoxina incapaz de generar lesiones entéricas. Asimismo, los aislados de C. perfringens analizados evidenciaron distintas características toxigénicas independientes de la presencia de Cp-PLC. Al parecer, la Cp-PLC no seria un factor esencial del C. perfringens en la producción de lesiones entéricas en casos de enterotoxemias en alpacas. Palabras Claves: Cp-PLC, Clostridium perfringens, enterotoxigenico / --- Enterotoxemia caused by Clostridium perfringens, causes a mortality neonatal rate up to 70%, this is why it is considered as the most important infections disease. Recent studies has suggested that Cp-PLC (Clostridium perfringens phospholipase C) is a main virulence factor responsible of the enterotoxemic lesions found in alpacas and other domestic animals. This study evaluated the toxigenic characteristics of Cp-PLC and of supercultures of C. perfringens isolates from enterotoxemia in alpacas associated with their levels of Cp-PLC production. The Cp-PLC purification protocol used was successful, showing that Cp-PLC as an enterotoxin enteric unable to cause injury. Similarly, C. perfringens isolates analyzed showed different toxigenic characteristics independently of the Cp-PLC production. Apparently, Cp-PLC does not be a essential factor from C. perfringens in the production of enteric lesions in cases of enterotoxemia in alpacas. Key Word: Cp-PLC, Clostridium perfringens, enterotoxigenic.