Project description:Long Read Genome Sequence Assemblies of Pasteurella multocida and Mannheimia haemolytica isolates from BRD-affected feedlots in Australia
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:Mannheimia haemolytica (M. haemolytica) cause mastitis in sheep, acute sepsis in newborn lambs, and co-infections with various pathogens, leading to bovine respiratory disease syndrome (BRDS), these infections have resulted in significant economic losses to both domestic and international farming industries. An in-depth understanding of the pathogenic mechanisms of M. haemolytica is crucial for the prevention and control of this disease. Outer membrane vesicles (OMVs) play a vital role in bacterial pathogenesis, serving as key mediators of interactions between Gram-negative bacteria and their hosts. However, the specific role of OMVs in the pathogenic process of M. haemolytica remains poorly understood. To address this, we isolated OMVs from the Mannheimia haemolytica Type A5 strain (MH-5) using ultracentrifugation and subsequently characterized their secretory properties, protein composition, and immunogenicity through electron microscopy, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and cellular experiments. The electron microscopy results indicated that the MH-5 strain secreted OMVs under natural growth conditions. Proteomic and bioinformatics analyses revealed that these OMVs contained 282 proteins, with significant enrichment in proteins related to immunity, iron metabolism, and catalytic activity. Cellular experiments demonstrated that, compared to the control group, the OMVs group exhibited a significant increase in the mRNA expression of IL-1β, IL-6, and TNF-α, with secretion levels increasing in a dose-dependent manner, thereby enhancing the inflammatory response. These findings lay the groundwork for further exploration of the role of OMVs in the pathogenesis of M. haemolytica and provide insights for the development of effective vaccines and antibiotics against this pathogen.
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.