Project description:The DNA content of bacteriophages from Bartonella grahamii was investigated by hybridization against cellular DNA from the same organism. Phage particles were isolated from plate grown bacteria as well as from different growth phases during culture in liquid medium.
Project description:Transfer RNA (tRNA) modifications play a crucial role in maintaining translational fidelity and efficiency, and they may function as regulatory elements in stress response and virulence. Despite their pivotal roles, a comprehensive mapping of tRNA modifications and their associated synthesis genes is still limited, with a predominant focus on free-living bacteria. In this study, we employed a multidisciplinary approach, incorporating comparative genomics, mass spectrometry, and next-generation sequencing, to predict the set of tRNA modification genes responsible for tRNA maturation in two intracellular pathogens—Bartonella henselae Houston I and Bartonella quintana Toulouse, which are causative agents of cat-scratch disease and trench fever, respectively. This analysis presented challenges, particularly because of host RNA contamination, which served as a potential source of error. However, our approach predicted 26 genes responsible for synthesizing 23 distinct tRNA modifications in B. henselae and 22 genes associated with 23 modifications in B. quintana. Notably, akin to other intracellular and symbiotic bacteria, both Bartonella species have undergone substantial reductions in tRNA modification genes, mostly by simplifying the hypermodifications present at positions 34 and 37. B. quintana exhibited the additional loss of four modifications and these were linked to examples of gene decay, providing snapshots of reductive evolution.
Project description:Transcriptional profiling of Bartonella quintana grown on a plate at 28C and 37C for various time points. Comparing each individual sample in cy5 to a pooled mix of all samples in cy3 to preserve a common denominator.
Project description:Myeloid Angiogenic Cells (MACs) were infected with the intracellular, bacterial pathogen Bartonella henselae (B.h.). Infected cells were seeded onto Matrigel coated plates. While uninfected cells showed no phenotypic changes and died over time, infected cells showed strong phenotypic changes and developed into complex 2D chord networks over the course of long term culture (eg 49d). To examine the changes in gene expression associated with the development of the B.h.dependent chord formation phenotype, RNA was isolated from MACs shortly after isolation (d4) and from cells of the chord structures (+B.h. Matrigel). As primary endothelial cells are also know to form chord networks when cultured on Matrigel, a sample of human umbilical vein endothelial cells (HUVECs) cultured on Matrigel for 12hr was also included in the analysis as a control.
