1 o157h7 one difficulty is deciding how different two

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Unformatted text preview: ferent strains. 1 O157:H7 One difficulty is deciding how different two isolates must be before one describes them as different species rather than as different strains. Taxonomy: Nomenclature Strain Three-Domain Classification Line lengths are based on genetic distances, i.e., longer lines reflect greater differences. Methods of Identification Note existence of other methods of visualization beyond Gram stain... Note Phenotype- vs. Genotype-based classification. Nomenclature: “Bacterial names may originate from any language, but they must be given a Latin suffix.” (i.e., they must be Latinized). Strain O157:H7 Recall Binomial Nomenclature. Three-Domain Classification Note that majority of genetic diversity is among single-celled organisms Phenotypic Characteristics Taxonomic Rank Note that not all groupings of microorganisms have taxonomic meaning: e.g., lactic acid bacteria, endosporeformers, or enteric pathogens. These are examples of classifying “mistakes” due to phenotypic similarity that results from convergent evolution. Microscopy: Gram stain, acid-fast stain, cell morphology, cell arrangements. Colony morphology: size, color, border shape, etc. Growth on Differential media: blood agar, MacConkey ag...
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