A enterite necrótica causada por Clostridium perfringens é, comprovadamente, um grande problema para frangos de corte, seja sob a forma clínica ou subclínica , com elevados prejuízos produtivos. Em perus, não está claramente identificada a influência deste patógeno sobre os resultados produtivos, e provavelmente por razões econômicas, o volume de pesquisa nesta área é limitado. Em dois experimentos consecutivos, conduzidos em granjas experimentais diferentes, e sobre cama nova e reutilizada, perus de 14 dias, sem medicação com anticoccidianos, foram inoculados, a partir de uma amostra de campo patogênica, com uma superdosagem de aproximadamente 1 x 1010 UFC/ml de Clostridium perfringens, tipo A; bactéria anaeróbica Gram positiva, que compõe a microflora intestinal dos perus. Lesões necróticas severas, com grande destruição da mucosa intestinal, foram observadas após o 4º dia de inoculação. Nos dois experimentos, a resposta dos perus à infecção foi diferente da descrita em frangos de corte. A mortalidade foi muito baixa ou nula e a recuperação das aves, independente da medicação utilizada, foi rápida com pouco ou nenhum comprometimento zootécnico. Escores das lesões histológicas foram desenvolvidos, para tentar correlacionar as lesões macroscópicas com as lesões microscópicas, mas a correlação foi baixa. Frente ao alto desafio observado, não foi possível avaliar adequadamente a ação do antimicrobiano utilizado. As respostas frente aos desafios de Clostridium perfringens nos perus, aparentam ser diferentes em relação às observadas em frangos de corte, sendo necessária cautela ao extrapolar padrões de uma espécie para outra. O uso de critérios subjetivos nas avaliações podem comprometer a tomada de decisão em relação aos tratamentos e as respostas esperadas. / Necrotic enteritis caused by Clostridium perfringens represents a major challenge in broilers, causing clinical or sub clinical diseases, and results in important economic losses for the poultry industry. In turkeys, however, the importance of this pathogen is not clearly defined, and there are few studies assessing its effects on the performance of turkeys, most probably for economic reasons. In two consecutive trials, conducted in two experimental farms, 14 day old turkey poults were reared on new and reused wood shavings litter, without any anticoccidials in the feed, and were inoculated with an overdose of approximately 1x1010 CFU/ml of a pathogenic field sample of Clostridium perfringens type A. This Gram positive anaerobic bacterium is a normal inhabitant of the gut micro flora in the enteric tract of turkeys. Severe necrotic lesions, with major damage to the intestinal mucosa were observed on Day 4 after inoculation. In both trials, the response to the turkeys to the clostridial infection was clearly different from what is described in the literature for broilers. The mortality rate was very low or inexistent, and the birds in all treatments groups recovered very fast, with little or no impact on performance results. An attempt was made to establish a pattern to correlate histological lesion scores with macroscopic and microscopic lesions, but the resulting correlation was very low. Considering the high level of challenge induced in both trials, it was not possible to evaluate in activity of the antibiotic in proper terms. The response of turkeys to a high level of challenge with Clostridium perfringens seems to be different when compared to what is observed in broilers under similar experimental conditions, and caution should be applied when using the same diagnostic methods for different species. The use of subjective criteria to assess and describe the lesions can lead to erroneous treatments decisions and misinterpretation of the responses to treatment.

A diarréia é o principal evento clínico observado no período neonatal em leitões (como conseqüência das doenças entéricas). Além de contribuir para piora no ganho de peso diário e conversão alimentar do animal causa aumento na mortalidade e gastos com medicamentos. O presente trabalho teve como objetivo determinar a freqüência dos principais agentes virais (rotavírus), bacterianos (E. coli, Clostridium perfringens tipo A e C e Clostridium difficile) e parasitários (coccídeos e Cryptosporidium spp.) envolvidos na diarréia neonatal em leitegadas caso (com diarréia) e controle (sem diarréia). Foram examinadas 276 amostras de fezes provenientes de 147 leitegadas com diarréia e 129 leitegadas sem diarréia, com idade variando entre 1 e 7 dias de vida em 28 unidades produtoras de leitões localizados no Estado do Rio Grande do Sul. Entre as amostras coletadas, 29,34% (81/276) foram positivas para pelo menos um agente pesquisado. Os coccídeos (20/276) e o C. perfringens tipo A (19/276) foram os agentes mais freqüentes. Nenhum dos enteropatógenos pesquisados obteve diferença significativa (p>0,05) entre as leitegadas caso e controle. Apenas o rotavírus (p=0,20) e o C. perfringens tipo A (p=0,16) apresentaram tendência de serem mais freqüentes em leitegadas com diarréia. Uma forte associação foi observada entre a ocorrência das diarréias e leitegadas mais novas (p<0,014). Foi observada pela primeira vez no Brasil a infecção pelo C. difficile, em 13,6% (17/132) das amostras, todavia a presença das toxinas nas fezes não teve relação com a diarréia. Os resultados obtidos indicam a necessidade de cuidados especiais quando da coleta de amostras para diagnósticos de monitoria de diarréias no período neonatal, pois é alta a chance de se obterem resultados falso positivos naqueles casos em que as doenças estiverem ocorrendo numa forma endêmica. / Diarrhea is the main clinical event occurring in pigs in the neonatal period,(as consequence of enteric disease). Besides contributing to losses in daily weight gain and feed conversion, diarrhea causes increased mortality and medication costs. The present work aimed to determine the frequency of the main viral agents (rotavirus), bacterial (E. coli, Clostridium perfringens type A and C and Clostridium difficile) and parasitic (coccidian and Cryptosporidium spp.) involved in neonatal diarrhea in case groups (with diarrhea) and controls (without diarrhea). We examined 276 fecal samples originating from 147 litters with diarrhea and 129 litters without diarrhea, with ages varying between 1 and 7 days, in 28 pig units of the state of Rio Grande do Sul, Brazil. Among the examined samples, 29.34% (81/276) were positive for at least one agent. Coccidia (20/276) and C. perfringens type A (19/276) were the most frequently isolated agents. None of the enteropathogens studied showed significant difference (p>0.05) between case and control litters. Only rotavirus (p=0.20) and C. perfringens A (p=0.16) had a tendency to present higher frequency in piglets with diarrhea. A strong association was observed between occurrence of diarrhea and litters with smaller age (p<0,014). Infection with C. difficile was diagnosed for the first time in Brazil, in 13.6% (17/132) samples; however the presence of the toxin in feces was not related to diarrhea. The present results suggest the need for special attention when sampling for the diagnosis or monitoring diarrhea in the neonatal period, as chances for obtaining false-positive results are high, especially when diseases are occurring endemically.

C. perfringens é uma bactéria anaeróbia presente no intestino delgado do homem e animais em equilíbrio e, sob a ação de alguns fatores predisponentes como mudança brusca de alimentação ou super alimentação, stress no manejo ou alto parasitismo intestinal, há a proliferação do microrganismo com a consequente produção de potentes toxinas que provocam a morte do animal. Dentre as toxinas principais destaca-se a toxina alfa, importante fator de virulência, produzida por todos os tipos de C. perfringens, sendo os pertencentes ao tipo A os maiores produtores. A fim de caracterizar o microrganismo em suspeitas de enterotoxemia em ruminantes, trabalhamos com 61 amostras de intestino delgado de bovinos e 12 de ovinos como grupo estudo e no grupo controle composto de animais hígidos levados ao abate, 73 amostras de intestino delgado de bovinos e 24 de ovinos. Foram realizados procedimentos de isolamento e tipagem molecular de C. perfringens e quantificação celular, detecção molecular da toxina &beta;2, além de avaliações moleculares qualitativa (PCR convencional) e quantitativa (PCR em tempo real) do gene da toxina alfa dos diferentes isolados. Em 29 amostras do grupo estudo bovino (47,54%) e em 4 (33,33%) do grupo estudo ovino isolou-se o microrganismo, em contrapartida no grupo controle bovino não houve isolamento do bacilo e 5 amostras do grupo controle ovino (20,83%) foram positivas. Houve diferença estatisticamente significante somente entre os grupos de bovinos (p<0,05). Todos os isolados (100%) foram classificados como tipo A, e os resultados das quantificações celulares de C. perfringens revelaram que todos os bovinos controle apresentaram <10 UFC/g de conteúdo enquanto que o grupo estudo apresentou mediana de 104 UFC/g com variações de <10 UFC/g até 108 UFC/g. Nos ovinos, a mediana no grupo controle foi 101 UFC/g assim como no grupo estudo, entretanto com clara separação de valores entre os grupos. Tanto na PCR convencional quanto na PCR em tempo real para detecção do RNAm da toxina alfa foi observado limiar de detecção de 102 cópias de cDNA por reação, porém provavelmente devido aos valores das amostras estarem próximos ao limite da sensibilidade analítica da reação, não foi observada boa reprodutibilidade da última. Já na reação molecular convencional, observou-se a presença de detecção de RNAm da toxina alfa em 60,52% dos isolados o que revela alguma diferença da presença do transcrito entre as culturas, já que nas cepas restantes não foi detectada a presença do RNAm em questão. A pesquisa do gene da toxina &beta;2 revelou sua presença em 54,55% dos isolados de C. perfringens corroborando com a afirmativa de que o gene está amplamente distribuído entre os ruminantes. A metodologia aplicada para avaliação da expressão do gene da toxina alfa nos isolados mostrou que há diferenças dos níveis de transcrição porém não permitiu quantificar esses valores. A tipagem molecular corrobora com outros estudos quanto à importância epidemiológica do tipo A nos quadros de enterotoxemia em ruminantes, e os dados da quantificação celular permite-nos concluir que animais sadios possuem um nível basal de C. perfringens <10 UFC/g de conteúdo que não possibilita o seu isolamento. / C. perfringens is an anaerobe present in small intestine of man and animals in equilibrium, and under some predisposing factors such as sudden feeding change or super feeding, rough management or high intestinal parasitism, the microorganism multiplies with the consequent production of potent toxins that can cause animal death. Amongst the main toxins, alpha toxin is an important virulence factor, that is produced by all C. perfringens types, and those belonging to type A are its higher producer. Aiming to characterize the microorganism in ruminants suspect of enterotoxaemia, we evaluated 61 bovine small intestinal samples and 12 sheep small intestines as the study group, and for the control group composed by higid animals led to slaughterhousing, 73 bovine small intestines and 24 ovine samples. We performed microbiological culture and molecular typing of C. perfringens isolates, cellular quantification, molecular detection of 2 toxin, and qualitative and quantitative molecular evaluations of alpha toxin from different isolates by means of conventional PCR and real time PCR, respectively. In 29 samples from the bovine study group (47.54%) and in 4 (33.33%) from ovine study group the microorganism was isolated, however in the bovine control group there was no isolation success and 5 samples from sheep control group (20.83%) were positive. There was statistically significant difference only between bovine groups (p<0,05). All isolates (100%) were classified as type A, and C. perfringens cellular quantification results showed that every control bovine presented <10 CFU/g of intestinal contents while the study group presented a median of 104 CFU/g with results ranging from <10 CFU/g to 108 CFU/g. In sheep, the median value in the control group was 101 CFU/g as in the study group, but with a clear division of values between the groups. We observed the threshold detection of 102 cDNA copies per reaction in both conventional and real time PCR reactions for alpha toxin mRNA detection, however since the samples quantification values were close to the analytical sensitivity of the test, we could not observe the reproducibility in the last technique. In the conventional PCR reaction, alpha toxin mRNA was detected in 60.52% of the isolates. This result reveals some difference in the transcript presence among the cultures, since we could not detect the presence of the described mRNA in the other isolates. Beta2 toxin gene was detected in 54.55% of C. perfringens isolates corroborating with the affirmative that this gene is widely distributed among ruminants. The methodology presented herein for the evaluation of alpha toxin gene expression showed that there are differences in the transcription levels, however it didnt allow to quantify these values. Molecular typing results agree with other studies regarding the epidemiological importance of type A in the enterotoxaemia processes in ruminants, and the cellular quantification data allow us to conclude that healthy animals show a basal level of C. perfringens <10 CFU/g of intestinal content that doesnt allow its isolation.

Clostridium perfringens é um dos microrganismos mais freqüentemente envolvidos em surtos de enfermidades transmitidas por alimentos. Este microrganismo pode ser classificado em cinco tipos toxigênicos (A-E), de acordo com a detecção dos genes codificadores de suas principais toxinas: alfa (cpa), beta (cpb), épsilon (etx) e iota (iap), sendo que técnicas moleculares empregando a PCR são atualmente utilizadas para genotipagem desses isolados. Alguns isolados de C. perfringens produzem uma enterotoxina (CPE) que é responsável pelos sintomas clínicos desenvolvidos em casos de toxinfecção alimentar, sendo que esta toxina é codificada pelo gene cpe. A simples detecção de C. perfringens em um alimento, mesmo naqueles suspeitos de causar surtos, não é suficiente para considerá-lo como de risco à saúde do consumidor. Isto porque dentre os isolados de C. perfringens apenas um número muito pequeno apresenta o gene cpe. Além disso, isolados de C. perfringens não produtores de CPE estão amplamente disseminados no ambiente, em alimentos e mesmo em fezes de pessoas. Desta forma, com o presente estudo verificou-se a freqüência de C. perfringens dentre isolados de clostrídios sulfito redutores, a freqüência de C. perfringens potencialmente enterotoxigênicos e sua variabilidade genética, de modo a evidenciar a importância dessas cepas como causadoras de doenças, além de fornecer subsídios para melhorar os conhecimentos sobre as características das cepas circulantes em nosso meio. Foram utilizados 335 isolados de clostrídios sulfito redutores provenientes de alimentos (126), solo (84) e fezes de animais (125). Dos 335 isolados, 146 (43,6%) foram caracterizados, através de reações bioquímicas e moleculares, comoC. perfringens, sendo 75 isolados (59,5%) provenientes de alimentos, 43 (51,2%) de solo e 28 (22,4%) de fezes de animais. Todas as cepas de C. perfringens analisadas foram tipadas como C. perfringens tipo A. Dos 75 isolados de C. perfringens provenientes de alimentos, 20 apresentaram o gene cpe, sendo 13 (65%) com localização cromossomal; nas demais cepas não foi possível determinar sua localização. Nos isolados de C. perfringens provenientes de solo e das fezes de animais não se verificou a presença desse gene. Das 20 cepas de C. perfringens que apresentaram o gene cpe detectou-se em 15 a produção de enterotoxina; as cinco cepas restantes não apresentaram esporulação no meio DUNCAN STRONG modificado, não sendo possível avaliar sua atividade enterotoxigênica. As 146 cepas de C. perfringens quando submetidas à PFGE geraram 69 perfis PFGE distintos, sendo 42 exclusivos para uma única cepa, indicando uma grande variabilidade genética, entre isolados provenientes de amostra de alimentos, fezes ou solo. A utilização de clostrídios sulfito redutores, ou mesmo de C. perfringens como indicador de possível risco à saúde dos consumidores pode levar à condenação desnecessária de alimentos, uma vez que existe baixa correlação entre costrídios sulfito redutores e C. perfringens, independente da fonte de isolamento, além da baixa freqüência do gene cpe nas cepas estudadas. / Clostridium perfringens is one of the most frequently microorganism involved in outbreaks of foodborne diseases. This microorganism can be classified into five toxigenic types (A to E), according to the detection of genes encoding its major toxins: alpha (cpa), beta (cpb), epsilon (etx) and iota (iap). Molecular techniques using PCR are currently used for genotyping this isolates. Besides the major toxins, some isolates of C. perfringens produce an enterotoxin (CPE) that is responsible for clinical symptoms developed in cases of food poisoning. This enterotoxin is encoded by the cpe gene. The simple detection of C. perfringens in food, even in those suspected of causing outbreaks, is not enough to consider it as a risk to consumers´ health. This happens because among the isolates ofC. perfringens only a very small number shows the cpe gene. In addition, isolates of C. perfringens that do not produce CPE are widespread in the environment, food and even in feces of humans. Thus, the present study examined the frequency of C. perfringens isolates among sulfite reducing clostridia, the frequency of potentially enterotoxigenic C. perfringens and its genetic variability in order to highlight the importance of these strains in causing diseases, and provides subsidies to improve the knowledge about the strains that are circulating in our environment. A total of 335 isolates of sulfite reducing clostridia from foods (126), soil (84) and animal feces (125) were used. Among the 335 isolates, 146 (43.6%) were characterized by biochemical and molecular reactions as C. perfringens, being 75 (59.5%) from foods, 43 (51.2%) from soil and 28 (22.4%) from animal feces. All strains of C. perfringens were typed as C. perfringens type A. Of the 75 isolates of C. perfringens from food, 20 had the cpe gene, and in 13 (65%) the gene was chromosomally located. In the other strains it was not possible to determine the location of this gene. In isolates of C. perfringens from soil and animal feces the cpe gene was not present. Amongst the 20 strains of C. perfringens positive for cpe, enterotoxin production was detected in 15. Five strains showed no sporulation in the medium modified Duncan Strong, being not possible to verify their enterotoxigenic activity. All C. perfringens were subjected to PFGE and generated 69 different PFGE profiles, being 42 unique to a single strain, indicating a great genetic variability among isolates from food, feces or soil. The use of sulfite reducing clostridia, or even C. perfringens as an indicator of possible health risk to consumers can lead to unnecessary condemnation of food, since there is low correlation between sulfite reducing clostridia and C. perfringens, regardless of source of isolation. This study also shows a low frequency of cpe gene in the strains indicating the low risk in causing foodborne disease.

Necrotic enteritis in poultry is caused by Clostridium perfringens type A, and is estimated to cost the worldwide poultry industry approximately $2 billion dollars a year, due to increased mortality and decreased feed conversion and weight gain. Very little is known about the pathogenesis of this disease due to the lack of a consistently reproducible experimental model. This dissertation outlines the development of an effective and consistent experimental model for necrotic enteritis in broiler chickens. It was also found that in vivo passage through the chicken's intestinal tract let to increased virulence; we increased the proportion of birds developing disease from 34.6% to 81.4%. Researchers have proposed that alpha toxin (CPA) is believed to be the critical virulence factor of the disease. All type A isolates have the potential to produce CPA, thus we challenged birds with numerous type A isolates that are virulent in other animal hosts. However, we found that they did not produce necrotic enteritis in broiler chickens. In addition, challenge with culture supernatant alone failed to produce gross lesions in the birds, although challenging with washed whole cell cultures did do so. Vaccinating birds with HIS-tagged recombinant CPA provided partial protection against disease; there was a 42.0% decrease in lesion development. The conclusion of this doctoral research is that CPA does have a role in the pathogenesis of necrotic enteritis in broiler chickens, but there are apparently other critical virulence factors involved in the development of 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%. A pesar de esto, existe poca información sobre los factores de virulencia (toxinas) del C. perfringens que participan en la etiopatogénesis de la enfermedad. El presente estudio tuvo como objetivo determinar el genotipo de los C. perfringens aislados de casos de enterotoxemia en base a la presencia de los genes (cpa, cpb, etx e iap) codificantes de las toxinas principales (α, β, ε y ι) así como el subtipo en base a la presencia de los genes cpe y cpb2 codificantes de la enterotoxina (CPE) y la toxina β2, respectivamente. En el estudio se analizaron 47 aislamientos de C. perfringens obtenidos de intestino de crías muertas de alpaca con signos clínicos y lesiones anatomopatológicas e histopatológicas correspondientes a enterotoxemia. El ADN de estos aislados fue extraído y analizado por la técnica de PCR Múltiple conteniendo iniciadores específicos para los genes codificantes de las toxinas mencionadas, encontrándose en 33/47 (70.2%) aislamientos sólo al gen cpa (genotipo A subtipo cpe-cpb2-), en 13/47 (27.7%) a los genes cpa y cpb2 (genotipo A subtipo cpe-cpb2+) y en 1/47 (2.1%) a los genes cpa, cpb y cpe ( genotipo A subtipo cpe+cpb2-). Estos resultados evidencian principalmente a la toxina α, así como a la β2 y β participar en la etiopatogénesis de la enterotoxemia en las alpacas. Palabras Clave: Clostridium perfringens, genotipificación, enterotoxemia, alpacas. / --- Enterotoxemia, caused by the Clostridium perfringens, is the most important infectious disease which affects alpacas, causing up to 70% neonatal mortality. In spite of this, little information exists on the virulence factors (toxins) of C. perfringens which play an important role in the etiopathogenesis of the disease. The objective of the present study was to determine the genotype of C. perfringens isolated from cases of enterotoxemia based on the presence of genes (cpa, cpb, etx and iap) which encode the main toxins (α, β, ε and ι), as well as the subtypes based on the presence of genes cpe and cpb2 which encode the enterotoxin (CPE) and β2-toxin respectively. A total of 47 isolations of C. perfringens were obtained from the small intestine of neonatal alpaca mortalities which had both clinical signs and gross and histological injuries typical of enterotoxemia. The DNA was extracted from these isolates and analyzed by PCR Multiplex using specific primers for the toxin genes. The cpa gene genotype A subtype cpe-cpb2-) was the only gene found in 70.2% (33/47) of the isolations. In 27.7% (13/47) of the cases the cpa and cpb2 (genotype A subtype cpe-cpb2+) genes were found and in 2.1% (1/47) the cpa, cpb and cpe (genotype C subtype cpe+cpb2-) genes were present. These results demonstrate the primary role of α-toxin, as well as the presence of β2 and β-toxins in the etiopathogenesis of enterotoxemia in alpacas. Key Words: Clostridium perfringens, genotypification, enterotoxemia, alpacas.

El presente estudio comparó los principales parámetros productivos de pollos de engorde suplementados con promotores de crecimiento con actividad anticlostridial en la dieta, se desarrolló en las instalaciones de la Facultad de Medicina Veterinaria de la Universidad Nacional Mayor de San Marcos, Lima -Perú. Se emplearon 575 aves distribuidas en 5 grupos de 115 animales con 5 repeticiones cada uno. G1 fue el grupo desafiado y tratado con lisozima encapsulada, G2 fue desafiado y tratado con fitobiótico (Humulus lupulus), G3 fue desafiado y tratado con Zinc bacitracina, G4 fue el control positivo sin promotor y desafiado y G5 fue el control negativo sin promotor y sin desafío. Se realizaron dos desafíos con Eimeria vía oral y agua de bebida (14 y 22 días) y un desafío con Clostridium perfringes (108 UFC/mL) vía oral a los 26 días. Los resultados mostraron que las aves de G1 y G2 ,tuvieron 56 y 42 g mas de peso corporal que G4. La mayor ganancia de peso promedio lo obtuvo G2 (2570.82 g). El mayor consumo acumulado lo presentó G4 (4797.82 g), G1 el menor (4676.12 g). La mejor conversión alimenticia la alcanzó G1 (1.78), seguido de G2 (1.79).El índice de eficiencia productivo Europeo arrojó una mejor eficiencia para G1 (349.16).Comparando G1 y G2 con G3 se obtuvo un 4.65% y 3.60% más de eficiencia productiva respectivamente. Sin embargo, el análisis de varianza de los parámetros productivos (peso promedio, ganancia de peso, índice de conversión alimenticia, consumo de alimento y el índice de eficiencia Europeo) en los cinco grupos del estudio no mostraron diferencia significativa entre ellos (p>0.05). Los resultados permiten concluir que la suplementación con productos alternativos a Zinc bacitracina tales como las lisozimas encapsuladas y fitobióticos (Humulus lupulus) mejoran el rendimiento productivo de los pollos de engorde bajo condiciones de reto de clostridios. Palabras clave: promotor de crecimiento, Clostridium perfringens, parámetros productivos, pollos de engorde. / --- This study compared the main productive parameters of broilers supplemented with growthpromoting activity anticlostridial diet, developed on the facilities of the Faculty of Veterinary Medicine of the Universidad Nacional Mayor de San Marcos, Lima-Peru. 575 birds divided into 5 groups of 115 animals with 5 repetitions each were used. Group G1 was challenged and treated with encapsulated lysozyme, G2 was challenged and treated with phytobiotics (Humulus lupulus), G3 was challenged and treated with zinc bacitracin, G4 was the positive control without promoter and challenged and G5 was the negative control without promoter and unchallenged. Two challenges with Eimeria oral and drinking water (14 to 22 days) and Clostridium perfringens challenge (108 CFU / mL) at 26 days oral route were performed. The results showed that birds of G1 and G2 were 56 and 42 g of body weight more than G4. The greater weight gain average was obtained by G2 (2570.82 g). G4 had the highest cumulative consumption introduced (4797.82 g), G1 the lowest (4676.12 g). G1 the best feed conversion (1.78), followed by G2 (1.79) .The European productive efficiency index showed a better efficiency for G1 (349.16) Comparing G1 and G2 against G3, obtained 4.65% and 3.60% over respectively production efficiency. However, analysis of variance of the production parameters (average weight, weight gain, feed conversion rate, feed intake and European efficiency index) in the five study groups showed no significant difference between them (p> 0.05). The results suggest that supplementation with alternative products such as Bacitracin Zinc and phytobiotics encapsulated lysozyme (Humulus lupulus) improve the productive performance of broiler chickens under clostridia challenging conditions. Keywords: growth promoter, Clostridium perfringens, production parameters, broilers.

Orientador: Ruben Pablo Schocken-Iturrino / Banca: Antonio Carlos Pizzolitto / Banca: José Moacir Marin / Resumo: A suinocultura vem ganhando espaço no mercado brasileiro, atualmente o interesse por alimentos saudáveis trouxe a carne suína como aliada e não mais como vilã. A partir disso, novas tecnologias como sistemas de confinamento, foram adotadas a fim de obter melhorias que visam principalmente à higiene do processo, alimentação balanceada dos animais e instalações adequadas. Nesse enquadramento, doenças infecciosas entéricas representam um problema importante na suinocultura, e estão envolvidas com grandes perdas econômicas e contaminação da carcaça comercializada. Considerando estes aspectos, o trabalho objetivou identificar Clostridium perfringens e Salmonella spp., a fim de alertar o setor suinícola sobre os riscos ainda disseminados que causam enfermidades nos suínos e contaminam os produtos que serão comercializados; e correlacionar a presença de Clostridium perfringens com interferências no ganho de peso dos animais. Foram realizadas contagens bacterianas para Clostridium spp. que apresentaram médias de 1,2x105 UFC/mL na primeira coleta e 7,88x102 UFC/mL na segunda coleta do confinamento, e nas amostras do frigorífico contou-se 1,8x104 UFC/mL. Os resultados obtidos por PCR foram positivos apenas para a toxina alfa (cpa), caracterizando uniformidade dos positivos (25%) para Clostridium perfringens tipo A do confinamento e 46,4% do frigorífico. Para Salmonella spp. com o gene invA foram detectados 9,5% de positivos nos animais do confinamento e 21,4% das amostras do frigorífico. E Salmonella Typhimurium com o gene fliC, foram positivas 3,57% no confinamento e 8,33% no frigorífico. Foi possível concluir que Clostridium perfringens e Salmonella spp. foram... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Swine production is becoming more popular in the Brazilian market, currently interest in healthy foods brought swine as an ally and not as a villain. From this, new technologies such as confinement systems were adopted in order to achieve improvements aimed primarily to process hygiene, a balanced diet of animals and adequate facilities. In this framework, enteric infectious diseases represent a important problem in the swine production, and are involved with large economic losses and contamination of carcass marketed. Considering these aspects, the study aimed to identify Clostridium perfringens and Salmonella spp. in order to alert the swine sector still scattered about the risks that cause diseases in swine and contaminate the products to be marketed; and correlating the presence of Clostridium perfringens with interference on weight gains of animals. Bacterial counts were performed for Clostridium spp presenting averages of 1.2 x105 CFU/ mL in the first test and 7.88 x102 CFU / mL in the second collection of confinement, and the samples of slaughterhouse told by 1.8 x104 CFU/ mL. The results obtained by PCR were positive only for the alpha-toxin (cpa), featuring uniformity of positive samples (25%) for Clostridium perfringens type A of confinement and 46.4% of the slaughterhouse. For Salmonella spp. with the invA gene were detected 9.5% of positive animals in confinement and 21.4% of samples from the slaughterhouse. And Salmonella Typhimurium with the gene fliC, were positive 3.57% in the confinament and 8.33% in the slaughterhouse. It was concluded that Clostridium perfringens and Salmonella spp. were... (Complete abstract click electronic access below) / Mestre

This research evaluates the effectiveness of a concentrated, buffered vinegar product (CBV) and a simple buffered vinegar product (BV) for controlling Clostridium perfringens outgrowth during extended cooling times of ready-to-eat roast turkey and roast beef respectively. Whole turkey breasts and beef inside rounds were injected with a typical brine, then ground and mixed with CBV (0.0, 2.01, 2.70 and 3.30% wt/wt) or BV (0.0, 1.75, 2.25, and 3.75% wt/wt) and a three-strain C. perfringens spore cocktail to a detectable level of ca. 2-3 log CFU/g. The meat was divided into 10g portions and vacuum packaged and stored frozen until tested. The meat was cooked in a programmable water bath to 71.6°C (160.8°F) in 5 hours. The meat was then cooled exponentially with the times between 48.9°C and 12.8°C (120°F and 55°F) lasting 6, 9, 12, 15, and 18 hours for the five different cooling treatments. The cooling continued until the temperature reached 4.4°C (40°F). C. perfringens counts were taken at 54.4°C (130°F) and 4.4°C (40°F). At a 2.01% concentration, CBV effectively limited C. perfringens growth to 1-log or less up to a 9-hour cooling treatment, while 2.70 and 3.30% concentrations were effective up to the 18 hour cooling treatment. BV had an inhibitory effect on C. perfringens outgrowth in roast beef, but did not limit growth to 1-log or less at any concentration tested for any of the cooling treatments.

Clostridium perfringens (CP) was evaluated as an additional indicator in assessing impacts and sources of microbial pollution in the Idaho-Utah Cache Valley . Point , nonpoint, river water, and animal fecal samples were analyzed for CP, total coliforms, fecal collforms, and fecal streptococci. Monthly river samples consistently contained <20 CP/100 mL , but concentrations of the other indicators varied significantly by location and date. Two sample stations consistently had CP concentrations greater than 20 / 100 mL . One of these stations was influenced by an upstream wastewater discharge . Chlorinated effluent from this trickling filter plant contained greater than 103 CP / 100 mL, but met a 400 FC/100 mL discharge standard. A consistent decrease in CP concentrations in samples taken downstream from this wastewater source were fo und, despite significant impact from adjacent nonpoint pollution. Lagoon and oxidation ditch wastewater effluents sampled contained <20 CP/100 mL. Nonpoint sources sampled (e.g . , cattle feedlot runoff) contained <20 CP / 100 mL and 102-104/100 mL coliforms and fecal streptococcus. Cattle, horse, and sheep feces analyzed contained 104-107/g coliforms and fecal streptococcus, but less than 102 CP/g. Nonpoint pollution from such animals may contribute significant coliforms and streptococci but not CP. Wastewater treatment effluents may or may not contain elevated levels of CP depending on factors such as wastewater residence time and particular treatment process employed. The occurrence of relatively high, i.e., >102 CP/100 mL, in areas impacted by nonpoint sources may suggest a municipal wastewater input. Coliform and streptococci indicators may not be able to distinguish municipal or domestic microbial loading in the presence of nonpoint source interferences in many circumstances.