Lecture 1_Ch 1.1 The science of Microbiology.pdf

Jawetz, Melnick, & Adelberg’s Medical Microbiology, Twenty-Eighth Edition Stefan Riedel Lectures slides by Dr. Jose Sapien Chapter 1: The Science of Microbiology...

Jawetz, Melnick, & Adelberg’s Medical Microbiology, Twenty-Eighth Edition Stefan Riedel Lectures slides by Dr. Jose Sapien Chapter 1: The Science of Microbiology 1.1 Introduction, 1.2 Biologic Principles and 1.3 Viruses Jawetz, Melnick, & Adelberg’s Medical Microbiology, Twenty-Eighth Edition  Introduction to the Science of Microbiology Microbiology is the study of microorganisms that exist as single cells or cell clusters; it also includes viruses, which are microscopic but not cellular organisms and worms → to be seen with Microscopy. Microorganisms have a tremendous impact on all life and the physical and chemical makeup of our planet. The rate of viral infections in the oceans is about 1 × 1023 infections per second, and these infections remove 20–40% of all bacterial cells each day. From: https://kids.frontiersin.org/articles/10.3389/frym.2021.569372 © McGraw-Hill Education, 2019 Biologic principles illustrated by Microbiology Microorganisms, cells, and viruses show an incredible variety of forms and functions, even though we can't see them with the naked eye. From: https://www.linkedin.com/pulse/golden-age-microbiology-aneesh-sudhakaran-nair-bindhu- © McGraw-Hill Education, 2019  Biochemistry, molecular biology, and genetics provide the tools required for analysis of microorganisms. Microbiology extends the horizons of these scientific disciplines. * Cellular and Acellular microbes. - Cellular: Eukaryotes and Prokaryotes (Bacteria, Archaea, Fungi, and Protists). - Acellular: Viruses. Virology focuses its studies on viruses. Alexey Solodovnikov (Idea, Producer, CG, Editor), Valeria Arkhipova (Scientific Сonsultant), CC BY-SA 4.0, via Wikimedia Commons © McGraw-Hill Education, 2019  Mutualism in biology is also called symbiosis. Symbiosis is a continuous association of different organisms. Many terms to describes the benefitted party. © McGraw-Hill Education, 2019  Viruses? Poulin, Robert, et al. (2015). If the relationship mainly benefits one party, it is described as parasitism. In parasitism, the host provides the primary benefit to the parasite. Parker, N., Schneegurt, M., Thi Tu, A.-H., Lister, P., & Forster, B. M. (2016). 4 Prokaryotic Diversity. In Microbiology. OpenStax. © McGraw-Hill Education, 2019  Most viruses and host relationships are considered…? A. Mutualism B. Parasitism C. Amensalism D. Commensalism © McGraw-Hill Education, 2019  Poulin, Robert, et al. (2015). If the relationship mainly benefits one party, it is described as parasitism. In parasitism, the host provides the primary benefit to the parasite. Parker, N., Schneegurt, M., Thi Tu, A.-H., Lister, P., & Forster, B. M. (2016). 4 Prokaryotic Diversity. In Microbiology. OpenStax. © McGraw-Hill Education, 2019  Are viruses bad? The exquisite cellular specificity of virus infection is being adapted to generate modifications of virus‐encoded proteins and the genetic manipulation of viral genomes = provides new and (hopefully) highly specific prophylactic vaccines as well as other therapeutic agents. © McGraw-Hill Education, 2019 Viruses Viral particles are generally small consisting of a nucleic acid molecule (DNA or RNA), enclosed in a protein coat (capsid) → Nucleic acid protection. Sometimes surrounded by an envelope of lipids, proteins, and carbohydrates. Proteins—frequently glycoproteins—comprising the capsid and/or making up part of the lipid envelope (e.g., HIV gp120) determine the specificity of interaction of a virus with its host cell. From: https://www.britannica.com/summary/virus © McGraw-Hill Education, 2019 Viruses The unique properties of viruses set them apart from living creatures. Only when it infects a cell does a virus acquire the key attribute of a living system—reproduction. Viruses are known to infect a wide variety of plant and animal hosts as well as protists, fungi, and bacteria. Tropism: restriction to infecting specific types of cells of only one host species. Parker, N., Schneegurt, M., Thi Tu, A.-H., Lister, P., & Forster, B. M. (2016). 6 Acellular pathogens. In Microbiology. OpenStax. © McGraw-Hill Education, 2019 Viruses - Cycle Attachment and Penetration: Viral surface proteins facilitate binding to and entry into the host cell. Replication and Assembly: Viral nucleic acid hijacks host cellular machinery to produce viral components. Integration (Optional): In some cases, viral DNA becomes integrated into the host genome as a provirus. Maturation and Release: New viral particles are assembled and released from the host cell. Viral Dependency: Some small viruses, like Hepatitis D, require assistance from other viruses (e.g., Hepatitis B) for replication. Parker, N., Schneegurt, M., Thi Tu, A.-H., Lister, P., & Forster, B. M. (2016). 6 Acellular pathogens. In Microbiology. OpenStax. © McGraw-Hill Education, 2019 Check your What makes viruses unique compared understanding to other microbes? How do viruses interact with their hosts? What unique structures do viruses possess? Do viruses have specific targets? © McGraw-Hill Education, 2019