Bacterial Arrangements 1 Arrangement of cells is dependent on pattern of division and how cells remain attached after division: • Cocci: • • • • • • Singles Diplococci – in pairs Tetrads – groups of four Irregular clusters – staphylococci and micrococci Chains – streptococci Cubical packets (sarcina) • Bacilli: • Diplobacilli – a pair • Chains – streptobacilli • Palisades Bacterial Arrangements 2 The figure of “Bacterial Arrangements.” Bacterial Arrangements 3 The figure of “Bacterial Arrangements” continues on this slide. Bacterial Arrangements 4 The figure of “Bacterial Arrangements” continues on this slide. The Size of Bacteria Classification Systems for Prokaryotes 1. Microscopic morphology 2. Macroscopic morphology – colony appearance 3. Bacterial physiology 4. Serological analysis 5. Genetic and molecular analysis Bacterial Taxonomy Based on Bergey’s Manual Bergey’s Manual of Systematic Bacteriology – five volume resource covering all known prokaryotes • Classification based on genetic information – phylogenetic • Two domains: Archaea and Bacteria • Five major subgroups with 25 different phyla Diagnostic Scheme for Medical Use Uses phenotypic qualities in identification • Restricted to bacterial disease agents • Divides bacteria based on cell wall structure, shape, arrangement, and physiological traits