Microbial taxonomy

• The word taxonomy came from three greek words
• Taxis – arrangement or order
• Nomos – law
• Nemein – means to distribute or govern
• Taxonomy – the science of biological classification
• Taxon or taxa - a group or level of classification or hierarchy categorized at different levels
• Systematics or phylogeny – the study of diversity of organisms and their evolutionary relationship
• Dichotomous key – a tool used for assigning an organism to a specific taxonomic catergory
• Taxonomic categories or hierarchy – an ordered group of taxonomic ranks used to classify organisms from general to specific
• What is it called?

  A) morphological characters

  
• What is it called?

  A) Physiological characters

  
• What is it called?

  A) Molecular characters

  
• What is it called?

  A) Ecological characters

  
• Major Taxonomical Characters:

  1. Morphological Characters
  2. Physiological Characters
  3. Geographic Characters
  4. Molecular Characters
  5. Ecological Characters
• What is it called?

  A) Classification

  
• Artificial system – share the same characteristics but organisms are not closely related to one another genetically
• Natural system – with many of the same characteristics and highly predictive
• Phylogenetic (phyletic) system – classifying organisms on the basis of descent from a common ancestor
• Phenotypic (Phenetic) Classification System - Groups do not necessarily reflect genetic similarity or evolutionary relatedness; based on convenient observable characteristics.
• Genotypic (Phylogenetic) Classification System - Considers characteristics of the genomes of organisms
• Family - encompasses a group of organisms that may contain multiple genera and consists of organisms with a common attribute
• Genus - Grouping similar genera into common families and similar families into common orders is used for classification of plants and animals, higher taxa designations are not useful for classifying bacteria.
• Species - Groups of populations that can potentially interbreed freely within and among themselves; Collection of bacterial strains that share common physiologic and genetic features and differ notably from other microbial species.
• Subspecies are taxonomic subgroups within a species.
• Biotype –a group of organisms having the same or nearly the same genotype
• Serotype – a group of organisms within a species that have the same type and number of surface antigens
• Genotype – may be given to groups below the subspecies level that share specific but relatively minor charadcteristics
• Clone is a population of cells derived from a single parent cell and identical
• Strain – came from pure cultures of the same species are not their antigen properties
• Serovar – a strain differentiated by serological means. Strains vary in their antigen properties
• Biovar (biotype) – strains that are differentiated by biochemical or other non-serological means
• Morphovar (morphotype) – a strain which is differentiated on the basis of morphological distinctions
• Isolate – a pure culture derived from a heterogeneous, wild population of microorganisms. It is also applicable to eukaryotic microorganisms as well as to viruses
• Classification of Hierarchy:

  1. Family
  2. Genus
  3. Species
• Three types of subspecies:

  1. Biotype
  2. Serotype
  3. Genotype
• Four types of Strains:

  1. Serovar
  2. Biovar
  3. Morphovar
  4. Isolate
• Strain differentiation methods – compare pure culture derived from a heterogeneous, wild population of microorganisms. The term isolate is also applicable to eucaryotic microorganisms as well as to viruses.
• Identify which is biotype, serotype, and genotype

  A) Biotype

  B) Serotype

  C) Genotype

  
• name the strain differentiation methods

  A) Protein profiling

  B) Immunological reactions

  C) Flow cytometry

  D) phage typing

  
• Nomenclature - branch of taxonomy concerned with the assignment of names to taxonomic groups in agreement with published rules