Lecture 01

• What are the methods to identify bacteria?

  Methods to identify and discriminate between bacteria
• Why is the identification of bacteria important?

  To distinguish strains and enable control strategies
• How does knowing the bacterial cause of diseases help?

  It enables control and prevention strategies
• What is antimicrobial resistance (AMR)?

  Resistance of bacteria to antibiotics
• What is the difference between broad-spectrum and narrow-spectrum antibiotics?

  Broad-spectrum affects many bacteria, narrow-spectrum targets specific ones
• What is the first step in the bacterial identification process?

  Collect a sample
• What is the purpose of subculturing a microbe?

  To ensure it is a pure culture
• How do test results help in identifying bacterial species?

  They are compared to a classification system
• What does the sensitivity of a technique depend on?

  Number of microorganisms in the specimen
• What does specificity depend on in bacterial identification?

  How unique a microorganism appears microscopically
• What are the phenotypic characteristics used for bacterial identification?

  Morphology and biochemical properties
• What is MALDI-TOF Mass Spectrometry used for?

  Identifying bacteria based on protein profile
• What is the purpose of serotyping?

  To identify bacterial strains using antibodies
• What is the role of culture media for microbes?

  To provide nutrients for microbial growth
• What is selective culture media?

  Media that inhibits unwanted organisms
• What is differential culture media used for?

  To distinguish between different species
• What does MacConkey agar differentiate?

  Between lactose fermenters and non-fermenters
• What happens when lactose is fermented on MacConkey agar?

  It turns the pH indicator bright pink
• What is the significance of Staphylococcus aureus on Mannitol salts agar?

  It ferments mannitol and is pathogenic
• What does a positive oxidase test indicate?

  Presence of cytochrome c oxidase enzyme

  
• What does the oxidation/fermentation (OF) test measure?

  Ability to metabolise carbohydrates like glucose
• What is the analytical profile index (API)?

  A classification system for bacteria
• What is PCR used for in bacterial identification?

  To amplify specific DNA sequences
• What is the significance of the 16S rRNA gene?

  It is stable and present in almost all bacteria
• How does FISH work in bacterial identification?

  Uses fluorescent probes to detect specific sequences

  
• What does whole genome sequencing determine?

  Order of bases in an organism's genome
• How does MALDI-TOF work for bacterial identification?

  Measures mass-to-charge ratio of ionised proteins
• What is serotyping based on?

  Antigenic proteins on the bacterial surface
• What are the advantages and disadvantages of different bacterial identification methods?

  Advantages:

  • Morphological tests are simple and quick
  • Biochemical tests provide detailed information
  • 16S rRNA sequencing is highly accurate

  
  

  Disadvantages:

  • Morphological tests may lack specificity
  • Biochemical tests can be time-consuming
  • 16S rRNA sequencing requires specialised equipment
• How does the identification process help in microbiology?

  It aids in understanding bacterial roles in diseases
• What is the role of the slide catalase test?

  To determine if bacteria produce catalase

  
• What does a positive coagulase test indicate?

  Presence of S. aureus in the sample
• What is the purpose of the oxidase test?

  To identify aerobic bacteria with ETC

  
• What does the oil overlay in the OF test create?

  An anaerobic environment for bacteria
• What is the significance of the phenotypic classification table?

  It compares positive and negative tests for identification
• How does the API strip work for bacterial classification?

  It uses biochemical tests to classify bacteria

  
• What is the role of ribosomes in bacterial identification?

  They are involved in protein synthesis and rRNA analysis
• What is the purpose of using primers in PCR?

  To target conserved regions of DNA
• What does the presence of mutations in the 16S rRNA gene indicate?

  It is rare due to its critical function
• How does the intensity of fluorescence in FISH relate to bacterial activity?

  Higher intensity indicates more active cells