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Chemotatic effect of different treatments on heterophils from healthy chickens and chickens with staphylococcal infectionAnwer, Mohammad 30 September 1992 (has links)
Staphylococcal tenosynovitis and osteomyelitis are world-wide problems of
broilers and broiler breeders caused by staphylococci. Pathogenesis of the disease is
ill defined. Avian heterophils are analogous to mammalian neutrophils but the
granules appear to be different.
The first chemotactic study was done on heterophils from chickens having
natural staphylococcal infection brought from a commercial broiler flock and on the
heterophils obtained from healthy 6-8 weeks old chickens brought from a local
hatchery as one day old chicks. In the second study, a chemotactic study was done
with three different staphylococci on heterophils obtained from healthy 6-8 weeks
old chickens brought from a local hatchery as one day old chicks.
Results for the first study showed a decreased chemotactic response in the
heterophils of chickens naturally infected with staphylococcus compared to healthy
chicken heterophils in response to minimum essential medium, pooled normal
chicken serum and E. coli endotoxin with normal chicken serum used as
chemoattractants. Second study results showed that pathogenic capsule type 5 and
type 8 Staphylococcus aureus isolates both induced chemotaxis in heterophils from
healthy chickens to a significantly greater degree than did a non-pathogenic
Staphylococcus xylosus. The Staphylococcus aureus isolate with capsule type 5
induced heterophil chemotaxis more than the capsule type 8 isolate. / Graduation date: 1993
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Development of a subunit vaccine against infectious bursal disease virusYeung, Wing-shing., 楊永成。. January 1999 (has links)
published_or_final_version / Zoology / Master / Master of Philosophy
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Methods for serological and PCR detection of Salmonella enteritidis in chickens.Meyer, Brendan. 08 November 2013 (has links)
Salmonella enteritidis (S. enteritidis) is a bacterial pathogen of chickens, and is currently
one of the leading causes of human food poisoning in the world. It is believed that
contaminated poultry products, especially eggs and egg products, have been responsible
for the dramatic increase in the incidence of this Salmonella serotype. Detection of
S. entertidis has conventionally involved bacteriological examination of samples, yet these
procedures are time-consuming which could lead to the rapid spread of S. enteritidis
through commercial flocks and potentially cause a human health risk. A number of
alternative detection techniques, mostly based on serological methods, have been reported
as effective diagnostic assays. However, some of these reports have not been supported by
representations of SDS-PAGE gels or Western blots. The objective of this study was the
evaluation of these serological techniques as well as a PCR amplification technique, which
has been reported to show promising results as a diagnostic method. The techniques
discussed in these reports were evaluated with regards to how rapid they were, their
specificity and their potential for use in local diagnostic laboratories.
Antigens from the outer surface of S. enteritidis were purified by several methods and their
antigenicity was tested by separating the antigens by means of SDS-PAGE, followed by
Western blotting using sera of chickens infected with S. enteritidis. A high degree of cross
reactivity was observed with many of the antigens tested, especially the
lipopolysaccharides (LPSs) and outer membrane proteins (OMPs) which had previously
been reported as containing antigens which could be used for specific detection of
S. enteritidis. This cross-reactivity could be explained by the conserved nature of many of
the LPS and OMP antigens among the Salmonella serotypes tested. A fimbrial antigen,
SEF14, which has been reported as a novel antigen, was seen as a prominent band at 14.3
kDa and was found to react with antibodies against S. enteritidis, yet not to the specificity
levels described in previous reports.
PCR amplification of the sefA gene sequence, which encodes for the SEF14 fimbrial
antigen, was found to give a predicted product of 310 bp when using a previously
described oligonucleotide primer pair. This amplified product was found to be specific for
S. enteritidis and other serogroup D Salmonella serotypes that are not poultry pathogens The cross-reactivity observed with many of the serological techniques used in this study,
meant that detection of S. enteritidis infection in chickens was considerably hindered.
However, the identification of further novel antigens by serological means, could result in the development of new vaccines. The specificity and speed afforded by PCR amplification indicated that this technique showed excellent potential for use in local diagnostic laboratories. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.
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