Project description:There is limited efficacy in vaccines currently available to prevent some animal diseases of bacterial origin, such as bovine respiratory disease due to Histophilus somni. Protective efficacy can potentially be improved if bacterial antigens expressed in the host are included in vaccines. During H. somni infection in the bovine host, biofilms become established and the availability of essential iron is restricted. To investigate potential proteins as protective antigens, the protein composition of spontaneously released outer membrane vesicles (OMVs) during iron-sufficient and iron-restricted growth, and the proteins expressed in the biofilm matrix were analyzed and compared. Proteomic analysis revealed a dramatic physiological change in H. somni as it transitioned from the planktonic form to the biofilm mode of growth. All transferrin-binding proteins (Tbp) previously identified in H. somni were detected in the OMVs, suggesting that OMVs could induce antibodies to these proteins. Two TbpA-like proteins and 7 total proteins were present in the OMVs only when iron was restricted, indicating that the expression of these Tbp was differentially regulated. More proteins associated with quorum-sensing (QS) signaling were detected in the biofilm matrix compared with proteins in the OMVs, supporting a link between QS and biofilm formation. Proteins ACA31267.1 (OmpA) and ACA32419.1 (TonB-dependent receptor) were present in the OMV and biofilm matrix, and predicted to be potential protective antigens using an immuno-bioinformatic approach. Overall, the results support the development of novel vaccines that contain OMVs obtained from bacteria grown to simulate the in vivo environment, and possibly biofilm matrix, to prevent diseases due to bacterial pathogens.
Project description:Objectives: To determine the transcripts that are differentially expressed in a hfq mutant. Hfq is an RNA chaperone that mediates many interactions between regultory RNAs and their mRNA targets. Analysis of the transcriptomes of the Pasteurella multocida wild-type strain and the Pasteurella multocida hfq mutant will allow for identification of genes controlled by hfq and the sRNAs with which it interacts. Methods: RNA sequencing was employed to determine the transcriptomes of a wild-type Pasteurella multocida strain and a hfq mutant strain. Comparison of these two transcriptomes allows for determination of differentially expressed genes and therefore those genes controlled by Hfq and sRNAs with which it interacts.
Project description:Objectives: To determine the transcripts that are differentially expressed in a hfq mutant. Hfq is an RNA chaperone that mediates many interactions between regultory RNAs and their mRNA targets. Analysis of the transcriptomes of the Pasteurella multocida wild-type strain and the Pasteurella multocida hfq mutant will allow for identification of genes controlled by hfq and the sRNAs with which it interacts.
Project description:Treatment of bacteria with antibiotics at or close to the inhibitory concentration leads to specific transcriptional responses often affecting target genes and targets pathways. A dataset of transcriptional profiles (compendium) induced by antibiotics with known mode-of-action (MoA) can be used to gain information on the putative MoA of novel substances with unknown MoAs. We used a Pasteurella multocida microarray to generate a compendium of transcriptional profiles and to obtain information on the putative MoA of a novel antibiotic compound. We also show a strong impact of the bacteriostatic antibiotics on P. multocida virulence gene transcription. Keywords: antibiotica treatment, time course
Project description:Bovine Pasteurella multocida (P. multocida) serotype A is considered to be one of the major causes of bovine respiratory disease (BRD), while its secretory proteins remain poorly understood. In this study, we employed data-independent acquisition (DIA) LC-MS/MS combined with bioinformatics analysis to obtain more comprehensive and accurate information on proteins secreted by P. multocida. A total of 154 proteins were obtained from the supernatants of two isolates of bovine P. multocida serotype A (high virulent PmCQ2 and low virulent PmCQ6) cultured in Martin or BHI media,and 52 putative secretory proteins were identified.
Project description:Treatment of bacteria with antibiotics at or close to the inhibitory concentration leads to specific transcriptional responses often affecting target genes and targets pathways. A dataset of transcriptional profiles (compendium) induced by antibiotics with known mode-of-action (MoA) can be used to gain information on the putative MoA of novel substances with unknown MoAs. We used a Pasteurella multocida microarray to generate a compendium of transcriptional profiles and to obtain information on the putative MoA of a novel antibiotic compound. We also show a strong impact of the bacteriostatic antibiotics on P. multocida virulence gene transcription. Keywords: antibiotica treatment, time course Midlog-grown cultures of P. multocida were treated for 10 or 30 min with 8 different antibiotics and one novel compound (thiazin) at minimal inhibitory concentrations (MICs) and were harvested. Control bacteria were not-treated and harvested at approximately the same optical density an OD578 of ~ 0.5. Total RNA was extracted from these samples and labelled with biotin. P. multocida whole genome transcriptional profiling was performed by hybridization on the custom-made Affymetrix microarray according to the manufacturerâs instructions. The experiments were done in triplicates.
Project description:Garlic is a popular flavor enhancer in modern cuisines. Although anti-atherosclerotic, anti-proliferative, hypolipidemic and chemopreventative effects of garlic are known for a long time, the mechanisms of garlic as a dietary supplement ramain largely unknown. We used microarrays to analyze the global programme of gene expression in control (cellulose) and garlic-fed C57BL/6J mice serendipitously infected with Pasteurella multocida and identified acute phase response genes, particularly Lcn2 and Orm2, as the major players in the innate response. Also dieraty garlic suppressed pasteurella infection in C57BL/6J mice.