Agent of whooping cough (pertussis), Bordetella pertussis is a small gram-negative coccobacilli.
Capsule, adhesion proteins, lipooligosaccharides, pili, IgA protease, and phase variations of H.influenzae play major roles in pathogenesis.
Acinetobacter are gram-negative coccobacilli, among them Acinetobacter baumannii accounts for most infections in humans in hospital settings.
Haemophilus species require accessory growth factors such as X (hemin), V (NAD) or a combination of both.
Gram-negative cocci of medical importance belong to the family Neisseriaceae which includes the genera Neisseria, Moraxella, Kingella, Acinetobacter.
Brucellosis, also known as “Undulant fever”, “Mediterranean fever” or “Malta fever” or “Bang’s disease” is a zoonosis caused by Brucella melitensis.
Q fever is caused by the intracellular bacterium Coxiella burnetii and is endemic in nearly every country in the world.
Haemophilus spp may grow on sheep blood agar very close to the colonies of Staphylococcus aureus.
Bacteria exist in four basic morphologies: cocci; rod-shaped cells, or bacilli; spiral-shaped cells, or spirilla; and comma-shaped cells, or vibrios.
