Bacterial adherence to epithelium is mediated through
Explanation: Fimbriae Certain (Gram-negative bacilli carry very fine, hair-like surface appendages called fimbriae or pili.
They are shorter and thinner than flagella Fimbriae can be seen only under the electron microscope.
Fimbriae function as organs of adhesion, helping the cells to adhere firmly to particles of various kinds Fimbriated bacteria form surface pellicles in liquid media.
Many fimbriated cells (for example Escherichia, Klebsiella) agglutinate red blood cells. Hemagglutination provides a simple method of detecting the presence of such fimbriae.
The hemagglutination is specifically inhibited by D- mannose (mannose sensitive) A special type of fimbria is the sex pili.
They are found on ‘male’ bacteria and help in the attachment of those cells to ‘female’ bacteria.
They do not mediate attachment to epithelium Flagella Flagella are the organs of locomotion.
Flagellum consists of three distinct parts the filament, the hook and the basal Flagella are made up of a protein (flagellin) Flagella are less than 0.02 Jim in thickness and hence beyond the limit of resolution of the light microscope.
They may, in some instances, be seen under dark ground illumination.
They can be visualised by special staining techniques in which their thickness is increased by mordanting, or by electron microscopy Mesosoxnes Mesosomes (chondroid) are vesicular,
convoluted or niultilaniinated structures formed as invaginations of the plasma membrane into the cytoplasm.
They are more prominent in Gram-positive bacteria. They are the principal sites of respiratory enzymes in bacteria and are analogous to the mitochondria of eukaryotes.
Mesosomes are often seen in relation to the nuclear body and the site of synthesis of crosswall septa,
suggesting that they coordinate nuclear and cytoplasmic division during binary fission