Microorganism adhere to host cell with the help of -

Some gram negative bacillli carry very fine , hair like surface appendages called fimbriae or pili. They are shoer and thinner than flagella and project from the cell surfaces as straight filaments . Fimbriae function as organ of adhesion helping the cells to adhere firmly to paicles of various kinds . This propey may serve to anchor the bacteria in nutritionally ourable microenvironments. Fimbriated bacteria form surface pellicles in liquid media Ref: Ananthanarayan & panikers textbook of microbiology 9th edition page no 20