Chair of Medical Biology, Microbiology, Virology, and Immunology CLASSIFICATION AND MORPHOLOGY OF BACTERIA. Lecturer As. Prof. O. Pokryshko

Bergey's Manual of Determinative Bacteriology – the "bible" of bacterial taxonomy. There are such levels of microorganisms’ organization: Species – Genus – Family – Class – Division – Kingdom Classifications system.

35 of the major groups of bacteria are distinguished primarily on morphological characteristics, namely: cell shapes (rods, cocci, curved, or filament forming); spore production; staining reactions; motility. Other groups are defined based on their metabolism, or combinations of morphological and physiological characteristics.

Some of the Major Groups of Bacteria in Bergey's Manual Spirochetes Very slender rods that are helically coiled around a central axial filament; includes the bacteria that cause syphilis and Lyme disease Gram-positive cocci Bacteria that have a cell wall structure that results in their staining blue- purple by the Gram stain procedure and that are spherical; include the streptococci and staphylococci Endospore- forming rods and cocci Bacteria that form heat-resistant bodies called endospores within their cells; include the bacteria that cause gas gangrene, botulism, tetanus, and anthrax

 Small, single-celled (unicellular) organisms.  Procaryotes: “Before nucleus”. Lack the following structures:  Nuclear membrane around DNA  Membrane bound organelles  Mitochondria  Chloroplasts  Golgi apparatus  Endoplasmic reticulum  Lysosomes Bacteria (Sing. Bacterium)

PropertyProkaryoticEukaryotic 1- Size μm 5-100μm 2- Cell Wall Present in all bacteria Except in Mycoplasma Present in Fungi & Algae 3- Cytoplasmic Membrane No Sterol Except in Mycoplasma Has sterols 4- Nuclear Membrane AbsentPresent 5- Nucleus AbsentPresent 6- Chromosome Single chromosom [not associtred with protein More than one [associated with histone] 7- Mitochondria AbsentPresent 8- Ribosome Sedimentation coefficient 70S 80S 9- Reproduction Asexual (binary fusion) Sexual & Asexual 10- Example Bacteria, Chlamydia, Rickettsiae Fungi & Protozoa

Bacterial Identification and Classification Shape - cocci, bacilli, spiral Shape - cocci, bacilli, spiral Arrangement - single, pairs, chains, clusters Arrangement - single, pairs, chains, clusters Size Size Gram-positive vs. Gram-negative Gram-positive vs. Gram-negative Aerobic vs. anaerobic Aerobic vs. anaerobic Physical/structural characteristics Physical/structural characteristics Biochemical characteristics Biochemical characteristics DNA analysis DNA analysis

The Dimension of Bacteria Relative size of a bacterial cell compared to other cells including viruses.

Gross morphology of bacteria Size - 1 to 10 mm - aids in identification Size - 1 to 10 mm - aids in identification Shape Shape Coccus - round Bacillus - rod - Fusiform, coccobacilli Spirillum - corkscrew - Flexible, undulating - spirochetes - Curved - vibrios

Cocci groupings Coccus Diplococcus Streptococcus Tetrad Sarcinae Staphylococcus

Chains of cocci Streptococcus pyogenes

Clusters of cocci Staphylococcus aureusSputum smear

Bacillus shaped bacteria Pseudomonas aeruginosa Escherichia coli

Bacillus shaped bacteria Fusobacterium

Bacillus chains Bacillus anthracis

Palisades arrangement Corynebacterium diphtheriae

Curved bacteria Vibrio cholerae Campylobacter

Curved bacteria Borrelia burgdorferi Spirilla