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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Library synthesis of neurotoxin inhibitors

Jones, Stephen Richard January 2001 (has links)
No description available.
2

The establishment of clostridial plasmid and chromosomal DNA in Escherichia coli and Bacillus subtilis

Collins, M. E. January 1984 (has links)
No description available.
3

Ensayo de tres programas de vacunación anticlostridial en alpacas

Yaya Luyo, Katherine Miluska January 2003 (has links)
La enterotoxetemia, enfermedad nfecciosa más importante en crías de alpaca, es causante de altas tasas de mortalidad y se caracteriza por ocasionar brotes con muerte súbita sin permitir la aplicación de tratamientos convencionales. El control está supeditado a la aplicación de medidas preventivas de manejo y a la aplicación de inmunoprofilaxis. En e presente trabajo se ensayaron tres programas de vacunación anticlostridial durante las tres campañas de parición ( 2001, 2002 y 2003) en una Unidad de Producción de una Empresa de Propiedad Social del departamento de Puno. Se empleó un anacultivo a base de cepas del Clostridium perfringes predominantemente de origen ovino ( cepas A,B;C y D) más una cepa tipo A aislada de alpaca. El efecto de la vacuna se realizó comparando tasas de mortalidad total y asociada a enterotoxemia ocurrida antes de la introducción de la vacuna(año 2000) con los 3 años con programa de vacunación (años 2001, 2002 y 2003). El programa # 1 (año 2000) con los 3 años con programa de vacunación (años 2001, 2002, 2003). El programa #1 (año 2001) administró la vacuna al 100% de las madres gestantes (dos dosis).y al 100% de las crías (una dosis). El programa #2 (año 2002) vacun´solamente al 100% de las crías (dos dosis) y en el programa #3(año 2003) se procedió a vacunar solamente al 100% de las madres gestantes (una dosis). El efecto de la vacuna fue evaluado comparando los índices de mortalidad neonatal total y asociadas a enterotoxemia, básicamente relizando diagnóstico de campo. La aplicación de la vacuna redujo lamortalidad neonatal total progresivamente, desde 33.41% (año 2000), hasta alcanzar el 25.17% (año 2001), 23.72% (año 2002) y el 9.38 % (año 2003). La 19.45% (año 2000) hasta 7.18%, 9.1% y 0.98% para los años vacunados (2001, 2002 y 2003). Comparando los diferentes programas de vacunación, el análisis de diferencia estadística de proporciones determinó que el anacultivo (vacuna) fue de progrma aplicado. Sin embargo, la reducción fue más palpable en aquellos programas que involucraron vacunar madres gestantes. / Enterotoxemia, the most mportant infectious disease in alpacas juvenile, is the cause og high mortaly and to present outbreaks with suden death that does not allow the application of conventional treatments. Cntrol depends on preventive handlng measures and the application of inmunoprofilaxis. The present work applied three programs of anticlostridial vaccnation during three campaigns of birth (2001, 2002 and 2003) in a Social propriety Enterprise´s Unite ofProduction in Puno. We employed an anacultivo with strains of Clostridium perfringens predominantly of ovine origin and a strain type A isolated enterotoxemia Mortality that occurred before the introduction of the vaccine (year 2000) with the three years with program of vaccination ( years 2001, 2002 AND 2003). In program #1 (year 2001) the vaccine was administered to 100# of pregnant mothers( two juveniles were vaccinated (100%) (two doss) and n program #3 (year 2003) only pregnant mothers were vaccinated (100%) ( a dose vaccinated). The application of the vaccine equally reduced the tital neonatal mortality associated with enterotoxemia from 19,45% (year 2000) to 25.17 % (year 2001), 23.72% (year 2002) and 9.38% (year 2003). The vaccine equally reduced the mortality associated wirh enterotoxemia from 19.45%(year 2000) to 7.18% ,9,1% and 0,98% in the years in wich vaccination was given (2001, 2002and 2003). Comparng the different programs of vaccination, the anlysis of statistical difference of proportions detrmined that the anaculativo (vaccine) was wffective for the control of enterotoxemia in alpacas independently of the type of application program. Nevertheless, the reduction in mortality was greater in the programs that involved vaccinating pregnant mothers.
4

Investigation into the role of Clostridium novyi in sudden death in pigs

Gomez-Duran, Charles Oliver January 1996 (has links)
No description available.
5

Deciphering components of synaptosomal neurotransmitter release with various neurotoxins

Ashton, Anthony Christopher January 2002 (has links)
No description available.
6

Ensayo de tres programas de vacunación anticlostridial en alpacas

Yaya Luyo, Katherine Miluska January 2003 (has links)
La enterotoxetemia, enfermedad nfecciosa más importante en crías de alpaca, es causante de altas tasas de mortalidad y se caracteriza por ocasionar brotes con muerte súbita sin permitir la aplicación de tratamientos convencionales. El control está supeditado a la aplicación de medidas preventivas de manejo y a la aplicación de inmunoprofilaxis. En e presente trabajo se ensayaron tres programas de vacunación anticlostridial durante las tres campañas de parición ( 2001, 2002 y 2003) en una Unidad de Producción de una Empresa de Propiedad Social del departamento de Puno. Se empleó un anacultivo a base de cepas del Clostridium perfringes predominantemente de origen ovino ( cepas A,B;C y D) más una cepa tipo A aislada de alpaca. El efecto de la vacuna se realizó comparando tasas de mortalidad total y asociada a enterotoxemia ocurrida antes de la introducción de la vacuna(año 2000) con los 3 años con programa de vacunación (años 2001, 2002 y 2003). El programa # 1 (año 2000) con los 3 años con programa de vacunación (años 2001, 2002, 2003). El programa #1 (año 2001) administró la vacuna al 100% de las madres gestantes (dos dosis).y al 100% de las crías (una dosis). El programa #2 (año 2002) vacun´solamente al 100% de las crías (dos dosis) y en el programa #3(año 2003) se procedió a vacunar solamente al 100% de las madres gestantes (una dosis). El efecto de la vacuna fue evaluado comparando los índices de mortalidad neonatal total y asociadas a enterotoxemia, básicamente relizando diagnóstico de campo. La aplicación de la vacuna redujo lamortalidad neonatal total progresivamente, desde 33.41% (año 2000), hasta alcanzar el 25.17% (año 2001), 23.72% (año 2002) y el 9.38 % (año 2003). La 19.45% (año 2000) hasta 7.18%, 9.1% y 0.98% para los años vacunados (2001, 2002 y 2003). Comparando los diferentes programas de vacunación, el análisis de diferencia estadística de proporciones determinó que el anacultivo (vacuna) fue de progrma aplicado. Sin embargo, la reducción fue más palpable en aquellos programas que involucraron vacunar madres gestantes. / Enterotoxemia, the most mportant infectious disease in alpacas juvenile, is the cause og high mortaly and to present outbreaks with suden death that does not allow the application of conventional treatments. Cntrol depends on preventive handlng measures and the application of inmunoprofilaxis. The present work applied three programs of anticlostridial vaccnation during three campaigns of birth (2001, 2002 and 2003) in a Social propriety Enterprise´s Unite ofProduction in Puno. We employed an anacultivo with strains of Clostridium perfringens predominantly of ovine origin and a strain type A isolated enterotoxemia Mortality that occurred before the introduction of the vaccine (year 2000) with the three years with program of vaccination ( years 2001, 2002 AND 2003). In program #1 (year 2001) the vaccine was administered to 100# of pregnant mothers( two juveniles were vaccinated (100%) (two doss) and n program #3 (year 2003) only pregnant mothers were vaccinated (100%) ( a dose vaccinated). The application of the vaccine equally reduced the tital neonatal mortality associated with enterotoxemia from 19,45% (year 2000) to 25.17 % (year 2001), 23.72% (year 2002) and 9.38% (year 2003). The vaccine equally reduced the mortality associated wirh enterotoxemia from 19.45%(year 2000) to 7.18% ,9,1% and 0,98% in the years in wich vaccination was given (2001, 2002and 2003). Comparng the different programs of vaccination, the anlysis of statistical difference of proportions detrmined that the anaculativo (vaccine) was wffective for the control of enterotoxemia in alpacas independently of the type of application program. Nevertheless, the reduction in mortality was greater in the programs that involved vaccinating pregnant mothers. / Tesis
7

Epidemiology and Pathophysiology of Clostridial Dermatitis (Cellulitis) in Turkeys

Lighty, Megan Elizabeth Folk 01 October 2015 (has links)
Clostridial dermatitis (CD) is a multifactorial disease of rapidly-growing turkeys. Clostridium septicum (Cs) has been identified as the primary cause, although C. perfringens (Cp) has also been implicated. Pathogenesis is not fully understood; however, it is hypothesized that Clostridia translocate from the gastrointestinal tract and spread hematogenously to capillary beds of skeletal muscles. Intense genetic selection has produced a rapidly growing bird that is heavier and less active. This may predispose birds to development of CD due to positional restriction of blood flow to the caudal breast and medial thigh. Subsequent reduction in oxygen tension within these tissues produces conditions conducive to germination, proliferation, and toxin production by previously trapped, non-replicative Clostridia. Studies were undertaken to investigate the epidemiology and pathophysiology of CD. Retrospective epidemiologic investigations evaluated incidence, risk factors, and economic impact of CD. Cs and Cp qPCR were performed on blood and tissue samples to demonstrate hematogenous spread in asymptomatic birds. Studies assessed the effect of prolonged recumbency by measuring oxygen saturation and surface temperature in dependent tissues. Tissues from CD cases were evaluated for Cs and Cp alpha toxin mRNA (CsA and CpA). Analyses were conducted to determine associations between these toxins and severity of histopathologic lesions. Whole genome sequencing was performed on the Cs type strain to identify other toxin genes. Flock type, breed, weight at time of processing, and stocking density affected disease incidence. Detection of Clostridium spp. in intestine, liver, and muscle from asymptomatic turkeys without cutaneous trauma implies hematogenous spread from an endogenous source. Focal polyphasic myonecrosis in dependent muscles of asymptomatic turkeys suggests an underlying predisposition to development of CD. Recumbency appeared to be associated with decreased perfusion to these tissues. Cs DNA was present in asymptomatic birds without corresponding CsA mRNA expression suggesting that organisms were present in a quiescent form. CsA was associated with CD while CpA did not appear to be involved in pathogenesis. Genome sequencing identified several coding regions which may correspond to other potentially active Cs toxins. These results support the proposed mechanism of pathogenesis and provide targets for further investigation of disease pathophysiology and vaccine development. / Ph. D.
8

Clostridium sordellii genome analysis reveals plasmid localized toxin genes encoded within pathogenicity loci

Couchman, Edward C., Browne, Hilary P., Dunn, Matt, Lawley, Trevor D., Songer, J. Glenn, Hall, Val, Petrovska, Liljana, Vidor, Callum, Awad, Milena, Lyras, Dena, Fairweather, Neil F. January 2015 (has links)
BACKGROUND: Clostridium sordellii can cause severe infections in animals and humans, the latter associated with trauma, toxic shock and often-fatal gynaecological infections. Strains can produce two large clostridial cytotoxins (LCCs), TcsL and TcsH, related to those produced by Clostridium difficile, Clostridium novyi and Clostridium perfringens, but the genetic basis of toxin production remains uncharacterised. RESULTS: Phylogenetic analysis of the genome sequences of 44 strains isolated from human and animal infections in the UK, US and Australia placed the species into four clades. Although all strains originated from animal or clinical disease, only 5 strains contained LCC genes: 4 strains contain tcsL alone and one strain contains tcsL and tcsH. Four toxin-positive strains were found within one clade. Where present, tcsL and tcsH were localised in a pathogenicity locus, similar to but distinct from that present in C. difficile. In contrast to C. difficile, where the LCCs are chromosomally localised, the C. sordellii tcsL and tcsH genes are localised on plasmids. Our data suggest gain and loss of entire toxigenic plasmids in addition to horizontal transfer of the pathogenicity locus. A high quality, annotated sequence of ATCC9714 reveals many putative virulence factors including neuraminidase, phospholipase C and the cholesterol-dependent cytolysin sordellilysin that are highly conserved between all strains studied. CONCLUSIONS: Genome analysis of C. sordellii reveals that the LCCs, the major virulence factors, are localised on plasmids. Many strains do not contain the LCC genes; it is probable that in several of these cases the plasmid has been lost upon laboratory subculture. Our data are consistent with LCCs being the primary virulence factors in the majority of infections, but LCC-negative strains may precipitate certain categories of infection. A high quality genome sequence reveals putative virulence factors whose role in virulence can be investigated.
9

Caracterización toxigénica de la fosfolipasa C del Clostridium perfringens (Cp-PLC) y su relación con aislados de C. perfrigens de casos de enterotoxemia en alpacas

Pérez Janampa, David Remy January 2010 (has links)
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.
10

Caracterización toxigénica de la fosfolipasa C del Clostridium perfringens (Cp-PLC) y su relación con aislados de C. perfrigens de casos de enterotoxemia en alpacas

Pérez Janampa, David Remy January 2010 (has links)
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.

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