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Title: Proteome analysis of bacterial pathogens
Author: Encheva, Vesela
ISNI:       0000 0001 3447 9353
Awarding Body: University of East London
Current Institution: University of East London
Date of Award: 2005
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The explosive progress over the past decade in the fields of genomics, bioinformatics and mass spectrometry has resulted in an increased capability to investigate and compare the global protein expression of cells, tissues and organisms. The main focus of this study was on characterising the protein expression profiles of different serovars of Salmonella enterica and different serotypeso f Streptococcusp neumoniae in an attempt to identify protein factors associatedw ith host specificity and virulence. A novel approach for typing of bacterial isolates using SELDI TOF MS was developed. A thorough investigation on the effect of different factors on the quality of the SELDI profile was carried out, and the potential of several software programmes to perform cluster analysis of the SELDI data was assessedB. oth cytosolic and membrane-associatepdr oteins were separatedb y 2D GE, and detailed referencem aps of the proteins expressedu nder standardisedc. onditions were created.I n the caseo f Salmonella, it containedm ore than 300 proteins. The comparativea nalysisa t the subspeciesle vel revealedt hat, in many cases,t he variation in the expression patterns was greater between strains with the same serospecificity than betweens erotypes/serovarss, uggestingt hat the serological properties of bacteria do not correlate with differential protein synthesis. However, in the case of Salmonella, where the serovars have different host specificity, the high resolution 2D gel maps revealed several serovar-specific proteins, including enzymes involved in the catabolismo f various substrates,o r in the processo f cell detoxification. Changesi n the expression patterns of the serovars in different growth conditions, such as pH or oxygen availability, were mostly universal amongst the serovars, although a few serovar-specific proteins were also present. The findings revealed parts of the proteome that alter their expression when the microorganism are subjected to unfavourable conditions such as while colonising the host, amongst other parts that remain stable. Overall, the results demonstrated the importance of analysing many different isolates when performing protein expression studies in highly variable microbial populations.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available