different types of bacteria shapes and info

Gram positive rods Haemophilus influenzae Gram-negative coccobacilli Francisella tularensis Gram-negative rod Bartonella henselae Gram-negative rod Cardiobacterium hominis Gram-negative rod Propionibacterium acnes Gram-negative rod Some common pleomorphic pathogenic bacteria are Name of the bacteria Gram-staining characteristics Corynebacterium spp. Some bacteria are variable in shape and are said to be pleomorphic (heterogeneous shape). Borrelia : They are corkscrew-shaped and are larger than the Treponema they can be viewed under a light microscope with Giemsa or Wright stains.Spirochetes ( Treponema, Leptospira, and Borrelia): Thin-walled, flexible, spiral rods ( Corkscrew shaped) seen only by darkfield microscope and generally not seen in a standard light microscope.Spiral-shaped bacteria (Image source: Ref-3) Streptomyces species form long, branched, multinucleate filaments called hyphae, which collectively form a mycelium. Such arrangement is called palisade arrangement and is found in Corynebacterium diphtheriae. In some bacillus, the cells are lined side by side like matchsticks and at angles to one another. These pleomorphic, long Gram-negative rods, often with tapered “pointy” ends. Vibrio cholerae Comma-shaped, curved, Gram-negative bacilli Campylobacter Curved Gram-negative rods that appear as comma or S-shaped Haemophilus influenzae Small, Gram-negative coccobacilli Fusobacterium spp. Listeria monocytogenes Small Gram-positive rods arranged in V or L-shaped formations similar to corynebacteria. Bacillus megaterium Gram-positive, streptobacilli (bacillus arranged in chains). Corynebacteria Gram-positive rods are club-shaped and arranged in palisades or V or L-shaped formations, also called “Chinese-Letter” appearance. Clostridium perfringens Large, Gram-positive, “boxcar” shaped bacilli. Clostridium tetani Gram-positive rod with characteristics “tennis racket shaped” or “drum stick appearance” due to presence of terminal spore. Name of the Bacteria Characteristics Shape Bacillus anthracis Large, Gram-positive rod with square ends, frequently found in chains. These arrangements are determined by whether the daughter cells stay together following division.Ĭocci can be found in pairs, chains, squares of four, cubes of eight, or grapelike clusters.Ĭomma-shaped cells generally define a basic characteristic of certain species (e.g., Vibrio species). Characteristics shape Examples Cocci in clusters Staphylococcus Cocci in chains Streptococcus Cocci in pairs with pointed ends Streptococcus pneumoniae Cocci in pairs with a kidney bean shape Neisseria Rods (bacilli) with square ends Bacillus Rods with rounded ends Salmonella Club-shaped rods Corynebacterium diphtheriae Fusiform Fusobacterium Comma shaped Vibrio Spirochetes (relaxed coil) Borrelia Spirochetes (tightly coiled) Treponema CocciĬocci appear in several characteristic arrangements such as diplococci (cocci in pairs), streptococci (cocci in chains), tetrads, staphylococci (cocci in grape-like clusters), and sarcinae. The arrangement of rods and spirochetes is medically less important. These arrangements are determined by the bacteria’s orientation and degree of attachment at the time of cell division. For example, certain cocci occur in pairs (diplococci), some in chains (streptococci), and others in grapelike clusters (staphylococci). In addition to their characteristic shapes, the arrangement of bacteria is essential. Spiral-shaped bacteria are called spirilla if the cells are rigid and spirochetes if they are more flexible and undulating.Rod-shaped bacteria having tapered ends are called fusiform, whereas others are characteristically club-shaped and may be curved or comma-shaped (Vibrios) or bent.

Very short rods that can sometimes almost be mistaken for cocci are called cocobacilli (singular: coccobacillus).Rods are called bacilli (singular: bacillus).Spherical or oval bacteria are called cocci (singular: bacillus).

Different types of bacteria shapes and info