A bacterial protective covering refers to structural layers that help bacteria survive hostile environments. The most notable example is the capsule, a polysaccharide or protein layer that surrounds the cell wall. In species like Streptococcus pneumoniae and Escherichia coli, the capsule enhances virulence by preventing phagocytosis and resisting immune defenses. Some bacteria also form endospores, which act as highly resistant dormant coverings under extreme stress.

These coverings are studied in microbiology for vaccine development and antimicrobial research. Understanding them also guides pharmaceutical production, including antibiotics such as cephalexin capsules wholesale, which are used to treat bacterial infections effectively by targeting susceptible organisms.