Viruses typically enter host cells through direct penetration of the cell membrane, using specialized proteins or glycoproteins on their surface.

The cell-mediated immune response, particularly cytotoxic T cells, plays a crucial role in recognizing and eliminating virus-infected cells by directly targeting and destroying them.

Immunoevasion refers to the strategies employed by pathogens to escape or counteract the host's immune defenses, allowing them to persist and cause infection.

Beta-lactam antibiotics, such as penicillin and cephalosporins, are a class of antimicrobial agents that specifically target and inhibit the synthesis of bacterial cell walls, leading to cell death.

Bacteria often cause disease by producing toxins, which are harmful substances that can damage host cells and tissues, leading to various symptoms and complications.

Tetracyclines are a class of antimicrobial agents that primarily target and inhibit the synthesis of bacterial proteins, interfering with their growth and replication.

Pathogenicity refers to the ability of a pathogen to cause disease in a host organism, including its capacity to survive, multiply, and damage host tissues.

Fluoroquinolones are a class of antimicrobial agents that primarily target and inhibit the synthesis of bacterial DNA, interfering with their replication and causing cell death.

Transmissibility refers to the ability of a pathogen to be transferred from an infected host to a susceptible host, either through direct contact, indirect contact, or via vectors.

Rifamycins are a class of antimicrobial agents that primarily target and inhibit the synthesis of bacterial RNA, interfering with their transcription and protein synthesis.

Virulence refers to the degree of pathogenicity of a microorganism, indicating its ability to cause severe disease or death in a host organism.

Polymyxins are a class of antimicrobial agents that primarily target and disrupt the synthesis of bacterial cell membranes, leading to leakage of cell contents and cell death.

Persistence refers to the ability of a pathogen to survive and remain viable within a host organism, often evading the host's immune defenses and causing chronic or recurrent infections.

Sulfonamides are a class of antimicrobial agents that primarily target and inhibit the synthesis of bacterial folic acid, an essential cofactor for various metabolic processes.

Infectivity refers to the ability of a pathogen to enter and establish an infection in a host organism, often quantified by the number of organisms required to cause infection.