| dc.description.abstract | Meningitis in newborns is a serious infection that causes mortality and neurological injury worldwide. The infection progresses from sepsis, and is dependent on the pathogen being able to cross the blood-brain barrier and invade the spinal fluid. One of the most common gram-negative organisms to cause neonatal meningitis is Escherichia coli. In this work, neonatal meningitis-causing E. coli strains H622 and IHE3034 were grown in clinical blood cultures alongside commensal E. coli K12 derivative J53. The bacteria were purified, lysed, and digested with proteases, before being analysed using mass spectrometry. The mass spectrometry results were quantified in order to create quantitative protein profiles of each bacterium. By using statistical and computational analysis, we compared the strains and identified proteins that were differentially expressed between the pathogenic strains and J53. The results indicate that the pathogenic strains share a number of regulatory mechanism, and demonstrate a higher expression than J53 of virulence factors, motility proteins, and proteins involved in capsule synthesis. In addition to the mass spectrometric analysis, the bacteria were characterised using genetic and phenotypic methods. The results indicate that the pathogenic strains H622 and IHE3034 share a closer evolutionary relationship than either does with J53. The mass spectrometry raw files have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD005779. | en_US |
