Final answer:
Bacteria use adhesion factors like fimbriae and pili for attachment; fimbriae allow adherence to host cells for colonization, whereas pili can also transfer genetic material.
Step-by-step explanation:
Two types of adhesion factors found in bacteria that facilitate their attachment to host cells or surfaces are fimbriae and pili. Fimbriae are short bristle-like proteins present by the hundreds that enable a bacterium to adhere to various surfaces, integral for pathogenic bacteria to colonize and establish infections. Pili are similar in structure to fimbriae but are typically longer and less numerous, aiding not only in attachment but also in horizontal gene transfer through a process known as bacterial conjugation.
For example, Haemophilus influenzae utilizes the Haemophilus adhesion and penetration factor (Hap) and a polysaccharide capsule for effective adhesion and evasion of the host's immune defense mechanisms. Similarly, Streptococcus species with M protein-modified fimbriae can inhibit phagocytosis, underscoring the role of these appendages in bacterial pathogenesis and immune system evasion.