MC3

• Microbiology


  An advanced biology course that specifically focuses on very small forms of life known as microorganisms/ microbes that may cause disease to its host
• Microorganisms/microbes


  • Bacteria, viruses, fungi, helminths

  
• Types of microbiology


  • Medical microbiology
  • Industrial microbiology
• Medical microbiology


  Study of interactions between man and microorganisms in which they co-exist, both beneficial and harmful
• There are 5 nonillion bacteria on planet earth
• Industrial microbiology


  Deals with food and beverages for safe human consumption
• Classifications of microorganisms


  • Commensals (normal flora)
  • Pathogens
  • Opportunistic pathogens
• Commensals (normal flora)


  Non-disease producing microorganisms
• Commensals (normal flora)


  • L. Casei - motility of the stomach
  • L. acidophilus - promotes acidity of vaginal tract
• Pathogens


  Disease-producing microorganisms
• Opportunistic pathogens


  Organisms that normally do not harm their host but can cause disease especially when the host's resistance is low
• Opportunistic pathogens


  • Candida albicans - an opportunistic agent of oral and genital infections in humans
  • Staphylococcus aureus - normal flora on human skin but may cause infections
  • Pseudomonas aeruginosa - may cause burn and external ear infections
• Classification of infective microorganisms according to risk group


  • Risk Group 1 - non-pathogenic, no or low individual and community risk
  • Risk Group 2 - can cause disease in humans, with treatment and prevention, moderate individual risk, low community risk
  • Risk Group 3 - cause serious disease in humans, treatments and vaccines for these diseases may exist, high individual risk, low community risk
  • Risk Group 4 - emerging infections w/o treatment and prevention and usually causes death, high individual and community risk
• Ways of pathogen transmission

  • Direct invasion - direct contact / indirect contact
  • Toxins production
• Types of toxins


  • Exotoxins - gram (+), secreted by the cell, heat labile proteins, ↑ antigenicity/ toxicity, systemic effect
  • Endotoxins - gram (-), produce when bacteria dies/ multiply, heat stable lipopolysaccharide-protein complexes, ↓ antigenicity/ toxicity, local effect
• Classification of pathogens


  • Virus
  • Bacteria
  • Parasites
  • Fungi
• Virus


  Smallest intact infectious agents with pathogenic potentials, 20nm - 300nm, best observed under electron microscopy, contain only one type of nucleic acid either RNA or DNA, non-cellular particles/ acellular = lifeless arrangement of molecules, lives inside the living cells, obligate intracellular organisms
• Bacteria


  Prokaryotic, contains both RNA & DNA, 1-5 um dm (average)

  
• Parasites


  Eukaryotic, protozoans, helminthes, arthropods
• Fungi


  Eukaryotic, molds; yeasts
• Fundamental types of cells

  • Prokaryotic/ Prokaryocytes
  • Eukaryotic/ Eukaryotes
• Prokaryotic/ Prokaryocytes


  Primitive type of nucleus, DNA located in an area called the nucleoid, not separated from other parts of the cell by a membrane, two domains: bacteria and archaea, lack true cell nucleus, mixture of nucleus and cytoplasm
• Eukaryotic/ Eukaryotes


  Have a nucleus where DNA is contained, true cell nucleus, with nuclear envelope, nucleolus, and chromatin, larger and contain many more organelles, endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, cytoskeleton
• Cell structure comparison


  • Eukaryotes (Fungi, Parasites)
  • Prokaryotes (Bacteria)
• A cell is defined as the fundamental living unit of any organism and the tissues of the body and exhibits the basic characteristics of life thus the basic unit of life and are involved in all processes of life. It was first discovered and named by Robert Hooke in 1665.
• Functions of the cell


  • Respiration
  • Nutrition
  • Excretion (phagocytosis)
  • Reproduction
  • Sensitivity (defense mechanism)
  • Growth
  • Movement of proteins
  • Transport of ions
• Parts of the cell and their functions

  • Cell wall
  • Cell membrane
  • Cytoplasm
  • Centrioles
  • Nucleus
  • Nucleolus
  • Ribosomes
  • Endoplasmic reticulum
  • Golgi bodies
  • Lysosomes
  • Mitochondria
• Passive transport


  Fundamental movement of ions and other molecular substances transport that occurs along a concentration gradient from high to low concentration, without necessary external energy for this
• Active transport


  Requires energy for the process by transporting molecules against a concentration or electrochemical gradient, uses adenosine triphosphate (ATP) to transport a substance that moves against its concentration gradient, low to high concentration
• Divisions of medical microbiology

  • Bacteriology
  • Virology
  • Mycology
  • Parasitology
  • Immunology
• Microbiology helps a nursing professional to understand the basic concepts of reproduction, morphology, biochemical characteristics, and genetics. They are involved in managing all aspects of patient's health and infection control in the hospitals. Nurse must have sufficient education and training in microbiology to perform many roles within clinical nursing practice, they must know microbiology to take care of patient and to protect oneself from pathogenic microorganisms preventing spread of infection and maintain the field as sterile.
• Significant scope of microbiology

  • Diagnostic
  • Prognosis of disease
  • Guidance in treatment
  • Source of infection
  • Detection of new pathogens and then development of vaccines
• Archaeans and Cyanobacteria/Cyanophyta were the first microorganisms
• Earliest known infectious diseases

  • Tuberculosis
  • Schistosomiasis
  • Dracunculiasis
  • Smallpox
• Archaea


  Single-celled organisms that are produced asexually and have unique metabolisms allowing them to live in the most inhospitable places on earth
• Cyanobacteria/Cyanophyta


  A phylum of gram-negative bacteria capable of photosynthesis, also known as blue-green algae although they are not usually scientifically classified as algae
• Earliest known Infectious Diseases

  • Tuberculosis
  • Schistosomiasis
  • Dracunculiasis
  • Smallpox
  • Rabies
  • Anthrax
  • Dysentery
  • Botulism
  • Measles
  • Typhoid fever
  • Diphtheria
  • Syphilis
• Tuberculosis


  A disease caused by germs (mycobacterium tuberculosis) that are spread from person to person through the air, usually affects the lungs
• Schistosomiasis


  Also known as bilharzia, is a disease caused by parasitic worms, second to malaria as the most harmful disease
• Dracunculiasis


  Also known as Guinea worm disease (GWD), is an infection caused by the parasite Dracunculus medinensis, spread by drinking water containing Guinea worm larvae