medical w1

• What is taxonomy?


  Classification based on shared characteristics.
• What is the hierarchical order of taxonomy?


  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• What is the scientific name for humans?

  Homo sapiens
• What does phylogeny measure?


  The evolutionary relationships between organisms.
• What are the steps in taxonomic classification of microbes?


  1. Classification: Ordering organisms into groups based on shared properties.
  2. Nomenclature: Naming the classified organisms.
  3. Identification: Determining species based on properties and comparison to known groups.

  
• Who is considered the founder of modern taxonomy?


  Carl Linnaeus
• What traditional properties are used in classification?

  Microscopy, morphology, response to oxygen, and biochemical tests.
• What are the molecular and genetic methods for classifying bacteria?


  • Choose appropriate molecular markers for a gene family.
  • Amplify and sequence.
  • Create evolutionary model.
  • Phylogenetic tree analysis and construction.

  
• What is the basis of phylogeny?


  All living things have genes that mutate randomly at low frequency.
• How do organisms differing by a few DNA base changes relate to evolutionary time?


  They have diverged more recently in evolutionary time.
• What is the universal phylogenetic tree based on?


  • 16S sRNA analysis
  • Three domains of life: Bacteria, Archaea, Eukarya
• What are extremophiles?


  Organisms that thrive in extreme environmental conditions.
• What is the temperature range for hyperthermophiles?


  113 – 200°C
• What is the pH level for acidophiles?


  pH 1.0
• What is the difference between biovar, morphovar, and serovar in bacterial classification?


  Biovar refers to biochemical variants, morphovar to morphological differences, and serovar to antigenic differences.
• What are the phenotypic and chemotaxonomic methods for classifying a previously unrecorded microbe?


  • Phenotypic: Physical, structural, or metabolic features.
  • Chemotaxonomic: Measures biochemical composition similarity.
• What is the difference between genotypic and phenotypic classification?


  Genotypic is based on genetic similarities, while phenotypic is based on physical features.
• What are the benefits of using genotypic classification?


  It provides precise genetic information for classification.
• What are the benefits of using phenotypic classification?


  It is often quicker and easier to perform than genotypic classification.
• What are the similarities and differences between Archaea and Bacteria?


  Similarities:

  • Shape, size, and microscopic appearance.
  • Multiply by binary fission.

  
  

  Differences:

  • Archaea do not have peptidoglycan.
  • Archaea genes are more similar to eukaryotes.

  
• What are the aims of the lecture on taxonomy and phylogeny?


  • Differentiate between Linnaean and modern phylogenetic methods.
  • Understand taxonomy and phylogeny concepts.
  • Discuss taxonomic tests for bacteria.
  • Explore limitations and benefits of classification systems.
  • Understand key differences between Bacteria and Archaea.

  
• What is the focus of the study on Pseudomonadaceae and related opportunistic pathogens?


  To introduce the bacterial group, focusing on Pseudomonas aeruginosa and Burkholderia genus
• What is the clinical significance of Pseudomonadaceae?


  It includes opportunistic pathogens that can cause infections in immunocompromised individuals
• What are the learning outcomes of the study on Pseudomonadaceae?


  Familiarity with phylogeny, diverse roles, and understanding P. aeruginosa as an opportunistic pathogen
• What is the faecal carriage rate of Pseudomonas aeruginosa?


  Between 15% and 25%, higher in vegetarians
• What is the classification hierarchy for Pseudomonas aeruginosa?


  • Domain: Bacteria
  • Phylum: Proteobacteria
  • Class: Gamma
  • Order: Pseudomonadales
  • Family: Pseudomonadaceae
  • Genus: Pseudomonas
  • Species: P. aeruginosa
• What are the characteristics of Pseudomonadaceae bacteria?


  They are Gram-negative bacilli, polar flagella, aerobic, and non-fermentative
• What are some genera included in the Pseudomonadaceae family?


  • Pseudomonas
  • Burkholderia
  • Xanthomonas
  • Ralstonia
  • Zymomonas
  • Sphingomonas
  • Stenotrophomonas
• What is the model opportunistic pathogen mentioned in the study?

  Pseudomonas aeruginosa
• In which patients is Pseudomonas aeruginosa particularly problematic?


  In immunosuppressed individuals, cystic fibrosis patients, and burns patients
• What type of infections can Pseudomonas aeruginosa cause in humans?


  Gastrointestinal, bladder, lungs, skin, and soft tissue infections
• How does Pseudomonas aeruginosa typically spread?


  Through person-to-person contact, fomite spread, and exposure to environmental sources
• What are the virulence factors of Pseudomonas aeruginosa?


  • Fimbriae & adhesins: Attachment and biofilm formation
  • Neuraminidase: Aids fimbriae attachment
  • Polysaccharide capsule: Protects against immune system
  • Endotoxin: May cause septic shock
  • Exotoxin A: Inhibits protein synthesis
  • Elastase, protease, haemolysins: Breaks down host cell fibers
  • Pyocyanin: Tissue damage and inflammatory response
  • Exopolysaccharides: Facilitate biofilm formation

  
• What environments can Pseudomonas aeruginosa thrive in?


  It can multiply in nutritionally poor environments like distilled water and photographic chemicals
• What are some common plant pathogens in the Pseudomonad group?

  Ralstonia solanacearum, Pseudomonas syringae, and Pseudomonas marginalis
• What disease does Burkholderia pseudomallei cause?


  Melioidosis
• What is a significant risk factor for severe melioidosis?


  Diabetes, renal failure, and HIV
• How does Burkholderia mallei differ from Burkholderia pseudomallei?


  Burkholderia mallei causes glanders and is endemic in certain regions, while B. pseudomallei is found in soil and water
• What are the symptoms of glanders caused by Burkholderia mallei?


  Ulceration, cutaneous lesions, pulmonary abscesses, and septicemia
• What is the target research paper for the test?


  It is available on SurreyLearn and will have five MCQ questions in Test 1