haemolytic

Virulence factors of Bordetella pertussis

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Bordetella pertussis is a small non-motile, non-sporing ovoid. Gram negative cocco-bacillus. It measures about 1-1.5µm x 0.3µm and is haemolytic. Capsulated (fresh isolates from patients), strict aerobes and fastidious. On staining with toludine blue, metachromatic granules are seen. The genes coding for B. pertussis virulence factors are under the control of two sets of genes, which … Read more

Culture media on the basis of physical state

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Media exists in three different forms. They are: Solid culture media. Semisolid culture media. Fluid culture media. Solid culture media: Mainly used in petri dishes as plate cultures. Can also be used in bottles or tubes as stab (deep) or slope cultures. Usually contain a concentration of 1-2% agar to yield a suitable gel. Used … Read more