Lecture 11 - Microbes PDF

Microbes ACMP 106: Human Biology II (3 Credits) Fred Aboagye-Antwi Day & time of office hours: Monday 10:15 am – 12:30 pm E-mail: [email protected] Monday, 19 July 2021...

Microbes ACMP 106: Human Biology II (3 Credits) Fred Aboagye-Antwi Day & time of office hours: Monday 10:15 am – 12:30 pm E-mail: [email protected] Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 1  Bacteria: Classification and Structure Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 2  Classification of Bacteria Bacteria: –Heterotrophs –Photosynthetic autotrophs –Chemosynthetic autotrophs Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 3  Bacteria - Heterotrophs Found everywhere (Ubiquitous) Parasites: live off of other organisms Saprobes/ Saprophytes: live off of dead organisms or waste (recyclers) – Eg. Yeast (Saccharomyces cerevisiae) Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 4  Bacteria: Photosynthetic Autotrophs Photosynthetic: make their own food (generates ATP) from sunlight – Eg. Rhodobacter, Rhodospirillum, Rhodopila, Rhodobium Cyanobacteria: blue-green, yellow, or red: Found in ponds, streams, moist areas – Eg. Anabaena, Oscillatoria, Lyngbya Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 5  Bacteria: Chemosynthetic Autotrophs Energy derived from breaking down inorganic substances (Eg. sulphur and nitrogen) Nitrogen fixation for plant use (i.e.: Make nitrogen in the air usable for plants {Very Important}) Eg. Thermodesulfovibrio yellowstonii, Gammaproteobacteria, Beggiatoa Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 6  Bacterial Cell Structure Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 7  Bacterial Structure Capsule: a loose polysaccharide structure protecting the cell from phagocytosis and desiccation Lipopolysaccharide: protects Gram-negative bacteria from complement-mediated lysis. A potent stimulator of cytokine release Fimbriae or pili: specialized thin projections that aid adhesion to host cells and colonization Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 8  Bacterial Structure Flagella: bacterial organs of locomotion -enabling organisms to find sources of nutrition and penetrate host mucus Slime: polysaccharide material secreted by some bacteria growing in biofilms -protects the organism against immune attack and eradication by antibiotics Spores: a metabolically inert form of bacteria triggered by adverse environmental conditions; adapted for long-term survival, allowing regrowth under suitable conditions Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 9  Classification of Bacteria Structure –Shape –Arrangement Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 10  Classification of Bacteria Gram Reaction (Nature of Cell Wall/ Membrane) Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 11  Classification of Bacteria Gaseous requirements Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 12  Classification of Bacteria Nature of Spores and Biochemistry Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 13  Classification of Bacteria Arrangement Paired: diplo Grape-like clusters: staphylo Chains: strepto Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 14  Classification of Bacteria Shape Rod: bacillus Spheres: coccus Spirals: spirillum Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 15  Examples Streptococcus: chains of spheres Staphylospirillum: Grapelike clusters of spirals Streptobacillus: Chains of rods Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 16 Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 17  FUNGI Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 18  Fungi (Division: Mycota) Name derived from mushrooms (Greek: mykes, Latin: fungus) Eukaryotes with similarities with plants – Possession of cell wall – Liquid-filled intracellular vacuoles – Microscopic cytoplasmic streaming – Lack of motility Differences from plants – Lacks photosynthetic pigments – Chemo-organoheterotrophs Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 19  Fungal Structure Vegetative body known as Thallus Thallus multiply branch into filaments Filaments known as Hyphae Hyphae consisting of: – Cell wall – Cytoplasm – Organelles – Nucleic acid Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 20  Fungal Structure Hyphae may be septate or aseptate Septate hyphae divided into “cells” by septa – Yet cytoplasm is continuous via a central pore in the septum – The pores allow for the flow of cytoplasm and nutrients throughout the mycelium – Members of the classes Basiodiomycetes and Ascomycetes form septate hyphae Aseptate hyphae also known as non-septate hyphae or coenocytic hyphae, form one long cell with many nuclei – More primitive form of hyphae; species with septate hyphae diverged from a common ancestor with coenocytic hyphae – Members of the class Zygomycetes are aseptate Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 21  Fungal Structure Entire hyphal mass of fungal thallus: Mycelium Tissue like aggregates of mycelium: Plectenchyma – Eg. “Flesh” of Mushroom Mycelium may form thick strands: Rhizomorphs Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 22  Fungal Morphology (Lamellae) (annulus) (stem/stape) (cup) Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 23  Fungi: Growth and Reproduction All parts of mycelium has potential for growth Apical growth: Hyphal elongation Highly diverse forms and mechanisms of reproduction Two kinds of reproduction – Asexual – Sexual Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 24  Classification of Fungi Designed for practical application with some phylogenetic considerations Nomenclature is binomial with names both – Generic – Specific E.g. Aspergillus niger Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 25  Classification of Fungi Classes (suffix –mycetes) Orders (suffix –ales) Families (suffix –aceae) Genera Species Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 26 Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 27  Importance of Microbes: Public health and industrial significance Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 28  Viruses Medical importance – DNA viruses Adenoviruses (Sore throat, conjunctivitis) Hepadnaviruses (Serum hepatitis) Herpes viruses (Herpes etc.) Papillomaviruses (Warts) Pox viruses (Small Pox) – RNA viruses Arboviruses (Insect borne encephalitis, yellow fever, zika) Arenaviruses (Meningitis, Lassa fever) Orthomyxoviruses (Influenza) Paramyxoviruses (Measles, mumps) Piconaviruses (Cold, meningitis, poliomyelitis) Retoviruses (HIV/AIDS, T-Cell Leukemia) Rhabdoviruses (Rabies) Rubella virus (German measles) Filoviruses (Ebola virus disease) Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 29  Emerging Viral Infectious Diseases Ebola virus disease (EVD) also known as Ebola hemorrhagic fever (EHF) – Ebola virus – First identified in Nzara and Yambuku along the Ebola river in 1976 – Intermittent occurrence of outbreaks – 25 outbreaks between 1976- to date West Nile encephalitis – West Nile Virus – First diagnosed in the West Nile region of Uganda in 1937 – Appeared in New York City in 1999 Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 30  Antiviral Drugs Host cell penetration inhibitors – Eg. Amantadin, Gammaglobulins, Rimantadin Nucleic acid synthesis inhibitors – Eg. Zidovudine, Zalcitabine, Didanosine, Foscarnet Virus replication inhibitors – (Neuramidase inhibition); Eg. Zanamivar, Oseltamivar Immunomodulators – Eg. Pavilizmab, Imiquimod Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 31  Viruses Environmental importance – Generally unknown – Managing populations (Keeping microbial populations in check [Bacteriophages and Mycoviruses]) – Potentially as a delivery tool for gene therapy Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 32  Emerging Subviral Infectious Diseases Prion (infectious proteinaceous material) Bovine Spongiform Encephalopathy (BSE/ Mad Cow Disease) Also causes Creutzfeldt-Jakob disease (CJD) New-variant CJD in humans related to cattle fed sheep offal for protein. Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 33  Bacteria Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 34  Bacteria Medical importance – Gastroenteritis (Camplyobacter jejuni, Escherichia coli, Salmonella sp., Shigella sp., Staphylococcus aureus, Clostridium difficile) – Syphilis (Treponema pallidum) – Tetanus (Clostridium tetani) – Lyme disease (Borrelia burgdorferi) – Plague (Yersinia pestis) Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 35  Antibacterial Drugs Classified based on: – mechanism of action, chemical structure, or spectrum of activity Bacterial cell wall/ membrane targets: – Penicillins and cephalosporins; polymyxins Bacterial enzymes targets: – Rifamycins, lipiarmycins, quinolones and sulfonamides) Bacterial protein synthesis targets: – Macrolides, lincosamides and tetracyclines Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 36  Bacteria Industrial importance –Food supplements Amino acids & Vitamins –Petrochemical industry –Organic solvents Acetone Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 37  Industrial sources of organic solvents from bacteria Sourced from: (Baker et al., 2011. Microbilogy, 4th Ed. Garland Science, NY., Pp 177) Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 38  Bacteria Pharmaceutical importance –Antibiotics Polymyxin Metronidazole (Antiprotozoan) Tetracycline –Hormones Insulin Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 39  Bacteria Environmental importance – Biodegradation Oil spills (Bioremediation) –Alcanivorax borkumensis and Oleispira antarctica Pollutants (Deinoccocus radiodurans) Wastewater treatment Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 40  Fungi Medical importance – Valley fever Coccidioides immitis or Coccidioides posadasii – Candidiasis Candida albicans – Athlete's foot Trichophyton rubrum Trichophyton mentagrophytes Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 41  Antifungal drugs (Fungicides) Polyene antifugals – Candicidin, Rimocidin, Nystatin Imidazole, triazoles and thiazole (Azole) antifungals – Miconazole, Fluconazole, Ravuconazole, Abafungin, Allylamines and Morpholines – Amorolfin Antimetabolite Antifungals – 5-Fluorocytosine Echinocandins – Caspofungin, Micafungin Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 42  Fungi Industrial importance – Fermentation and food Wine Beer Bread Yogurt Cheese Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 43  Fungi Pharmaceutical importance – Antibiotics Penicillin (Penicillium chrysogenum and P. griseofulvum) Cephalosporin (Cephalosporium acremonium and Acremonium chrysogenum) Cyclosporin (Tolypocladium inflatum) Cilofungin (Aspergillus nidulans and A. rugulosus) Ergotamine (Claviceps purpurea) Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 44  Fungi Environmental importance –Wastewater treatment Filamentous fungi, Bjerkandera adusta –Degradation of complex organic matter Lignin in wood –Aspergillus fumigatus, A. niger, Cladosporium sp., Fusarium sp., Myrothecium verrucaria Monday, 19 July 2021 ACMP 106 (Human Bilogy II) 45