Transcriptomic differences noted in Glaesserella parasuis between growth in broth and on agar

• Published in: PloS one Vol. 14; no. 8; p. e0220365
• Main Authors: Hau, Samantha J, Mou, Kathy T, Bayles, Darrell O, Brockmeier, Susan L
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.08.2019; Public Library of Science (PLoS)
• Subjects: Agar; Agar - pharmacology; Animal diseases; Animals; Antigens; Bacteria; Bacterial Proteins; Bacterial Vaccines; BASIC BIOLOGICAL SCIENCES; Bioinformatics; biological transport; Biology and Life Sciences; Causes of; cell metabolism; Cell Proliferation - drug effects; Cellular manufacture; Culture Media - pharmacology; Deoxyribonucleic acid; DNA; DNA transcription; Gene expression; Gene Expression Profiling; Genes; Genes, Bacterial; Genetic aspects; Genomes; Genomics; Gram-negative bacteria; Growth; Haemophilus parasuis - genetics; Haemophilus parasuis - growth & development; Hemophilus infections; Hogs; Homology; Immune response; Immune system; Immunologic research; Immunotherapy; Infections; Lipids; Lipids - biosynthesis; Livestock; metabolic pathways; Pork industry; Prevention; Principal components analysis; Proteases; Protein Biosynthesis - drug effects; Proteins; Quality; Research and analysis methods; RNA sequencing; Substrates; Swine; Swine diseases; Transcription; Transcription (Genetics); transcriptome analysis; Vaccine efficacy; Vaccines; Virulence; Virulence (Microbiology); Virulence - genetics; Weaning; United States; United States > US; Iowa; Tennessee
• DOI: 10.1371/journal.pone.0220365
• ISSN: 1932-6203

Glaesserella parasuis is the cause of Glӓsser's disease in pigs and is a significant contributor to post-weaning mortality in the swine industry. Prevention of G. parasuis disease relies primarily on bacterin vaccines, which have shown good homologous protection and variable heterologous protection. Bacterin production involves large scale growth of the bacteria and proteins produced during the proliferation phase of production become important antigens that stimulate the immune response. In order to evaluate genes activated during G. parasuis growth on different media substrates, the transcriptome of broth and agar grown G. parasuis strain 29755 were sequenced and compared. The transcription of most purported virulence genes were comparable between broth and agar grown G. parasuis; however, four virulence-associated genes, including ompA and vapD, had elevated expression under agar growth, while six virulence-associate genes had elevated expression during broth growth, including several protease genes. Additionally, there were metabolic shifts toward increased protein and lipid production and increased cellular division in broth grown G. parasuis. The results contribute to the understanding of how growth substrate alters gene transcription and protein expression, which may impact vaccine efficacy if immunogens important to the protective immune response are not produced under specific in vitro conditions. While the results of this work are unable to fully elucidate which growth medium presents a transcriptome more representative of in vivo samples or best suited for bacterin production, it forms a foundation that can be used for future comparisons and provides a better understanding of the metabolic differences in broth and agar grown bacteria.