Marzieposie

• Introduction to Diagnostic Bacteriology
• CLINICAL BACTERIOLOGY
• Transcriber: Riyoma Surell
• LEC 1
• 2nd SEM
• Page 1 of 3
• OLFU College of Medical Laboratory Science
• Batch 2023
• Outline


  • Define Microbiology, Medical Microbiology and Diagnostic Microbiology
  • Define terms related to infectious process and disease transmission
  • Outline some of the contributions of Leeuwenhoek, Pasteur and Koch to Microbiology
  • Identify the careers in Microbiology
• Microbiology


  A branch of biology which deals with the study of living organisms that are too small to be seen by the naked eye
• Medical Microbiology


  A branch of medical science which deals with the study of medically important microorganisms specifically their role in human disease which includes diagnosis, treatment and prevention of infectious diseases
• Diagnostic Bacteriology


  A branch of medical microbiology that focuses on the laboratory identification of medically important bacteria by phenotypical (physical characteristic) and genotypical (genes) characterization including antibiotic susceptibility testing
• Microbiology


  • Study of living organism (microbes)
  • Study of certain nonliving entities as well as certain living organisms
• Microbes


  Are said to be ubiquitous, meaning they are virtually everywhere
• 4 Groups


  • Viruses
  • Bacteria
  • Fungi
  • Parasites
• Viruses

  • Very simple microbes, consisting of nucleic acid, a few proteins, and (in some) a lipid envelope
  • Completely dependent on the cells they infect for their survival and replication
• Bacteria


  • With both RNA and DNA, metabolic machinery for self-replication and a complex cell wall structure. Asexual
  • Prokaryotic – simple unicellular organisms (no nuclear membrane, mitochondria, endoplasmic reticulum)
• Fungi


  Subdivided into single-celled organisms (yeasts) or multi-celled organisms (molds), with a few medically important members existing in both forms (dimorphic fungi)
• Parasites


  Subdivided into single-celled organisms (protozoa) or multi-celled organisms (worms and bugs)
• Pathogens


  Disease causing microorganisms such as bacteria, fungi, protozoans and viruses
• Types of Pathogens


  • True Pathogen
  • Opportunistic Pathogens
• True Pathogen


  Refers to an organism that will cause disease in a healthy host
• Opportunistic Pathogens


  Refers to organisms that will cause disease in an immunocompromised host
• Pathogenicity


  Refers to the ability of an organism to cause disease in a host organism
• Virulence


  Refers to the degree of pathogenicity; the power by which a pathogen can cause severe disease
• Pathogenic Determinants/ Virulence Factors


  Refers to any genetic, biochemical or structural features that enable a pathogen to cause disease in a host organism
• Types of Infection


  • Endogenous Infection
  • Exogenous Infection
  • Acute Infection
  • Chronic Infection
  • Nosocomial Infection
  • Zoonotic Infection (Zoonosis)
  • Subclinical/ Asymptomatic/ Nonapparent
  • Clinical/ Symptomatic/ Apparent
• Endogenous Infection


  Infection arising from colonizing flora
• Exogenous Infection


  Infection arising from invading pathogen from the external environment
• Acute Infection


  Rapid/ sudden onset of signs and symptoms which are usually severe to fatal that may lead to death
• Chronic Infection


  Gradual onset of signs and symptoms that are usually mild to moderate that may progress to long standing infection
• Nosocomial Infection


  Infection acquired during hospitalization
• Zoonotic Infection (Zoonosis)


  Is an animal disease which can spread to humans; animal acquired infection
• Subclinical/ Asymptomatic/ Nonapparent


  No obvious appearance of signs and symptoms and the person is unaware of the infection
• Clinical/ Symptomatic/ Apparent


  Associated with presence of overt signs and symptoms of the disease
• Disease


  An altered health state in an infected host
• Infectious Disease


  Is an illness caused by a pathogen which invades body tissues and causes damage
• Communicable Disease


  Is an infectious disease that is capable of spreading from person to person
• Symptoms


  Refers to any subjective evidence of disease. These are usually perception of the patient having the disease such as headache, dizziness, etc.
• Signs


  Refers to readily observable evidence of disease. These are usually physical manifestation of the disease such as rashes, bleeding etc.