MB - INTRO

• Microbiology


  Study of microorganisms such as bacteria, fungi, viruses and similar organisms that cannot be seen with the naked eye
• The need to study these minute organisms started when scientists discovered the association of microbes to specific diseases
• Normal flora


  Microorganisms that normally reside at a given site and under normal circumstances does not cause disease
• Pathogen


  An infectious agent that causes disease or illness to its host, disrupting normal physiology of the host
• Pharmacists' roles in microbiology


  • Manufacture of microbiologically sterile medicines
  • Protection against microbial contamination and spoilage
  • Detection of hazardous microorganisms in medicines and antibiotics' manufacture and assay
• Classification of microorganisms by structure


  • Subcellular (viruses)
  • Prokaryotic (bacteria)
  • Eukaryotic (fungi, parasites including protozoans)
• Genus


  Category of biologic classification, e.g. Streptococcus

  
• Species


  Represents a distinct type of microorganisms, e.g. Streptococcus mutans, S.pyogenes, S.agalactiae

  
• Bacteria


  • Single-celled prokaryotic organisms
  • Reproduce rapidly
• Bacterial classification methods


  • Shape
  • Ability to retain dyes
  • Ability to grow with/without oxygen
  • Biochemical reactions
• Bacterial shapes


  • Coccus (spherical, round, or ovoid)
  • Bacillus (rod-shaped)
  • Spirillum (spiral-shaped)
  • Vibrio (comma-shaped)
• Gram's stain


  Identifies Gram-positive and Gram-negative bacteria
• Acid-fast stain/Ziehl-Neelsen staining


  Identifies Mycobacterium
• Bacterial growth conditions


  • Aerobes (grow best in presence of oxygen)
  • Anaerobes (grow best in absence of oxygen)
• Bacterial identification tests


  • Catalase test
  • Hemolysis test
  • Motility test
  • Citrate test
• Viruses


  • Smallest, obligate intracellular parasites
  • Must live and grow in living cells of other organisms
  • Can direct the cell machinery to produce more viruses
• Virion


  A complete virus particle
• Viral structure


  • Nucleic acid (single- or double-stranded RNA or DNA)
  • Capsid (protein coat shell to protect the viral genome, attaches the virion to specific receptors)
  • Envelope (additional protective coat, derived in part from modified host cell membranes, consists of a lipid bilayer)
• Viral symmetry


  • Icosahedral
  • Helical
  • Complex
• Viral genome and replication


  • DNA or RNA, single-stranded or double-stranded, linear or circular
  • Different genome types necessitate different replication strategies
• Illnesses caused by viruses


  • Influenza
  • AIDS
  • Herpes
  • Mumps
  • Hepatitis
  • Rubella
  • Warts
  • Measles
• Vaccines are available for many viruses
• Antiviral drugs are a class of medication used specifically for treating viral infections
• Fungi are eukaryotic protista, differ from bacteria and other prokaryotes
• Chitin


  Polysaccharide in fungal cell walls, provides rigidity and support, making fungi resistant to antibiotics like penicillins
• β-glucan


  Polysaccharide in fungal cell walls, site of action of some antifungal drugs
• Ergosterols


  In fungal cytoplasmic membranes, site of action of antifungal drugs like amphotericin B and azole group
• Fungal spores may be important as human allergenic agents
• Fungal morphology


  • Dimorphic (hyphae at ambient temperatures, yeasts at body temperature)
  • Hyphae (branching filaments)
  • Mycelium (tangled mass of hyphae)
  • Yeast (unicellular budding)