Bacteria causing catheter infections attach to surfaces using:

A. antisepsis: Antisepsis refers to the application of chemical agents, known as antiseptics, directly to living tissues to destroy or inhibit the growth of vegetative pathogens. Common antiseptics include alcohols, iodine preparations, chlorhexidine, and hydrogen peroxide. These agents are widely used before injections, surgical procedures, and wound care to reduce microbial load and prevent infection.

B. sanitization: Sanitization involves reducing the number of microorganisms on inanimate objects to levels considered safe according to public health standards. This process is commonly used in food preparation areas, restaurants, and public facilities. It does not necessarily destroy all vegetative pathogens and is not intended for use on living tissues.

C. sterilization: Sterilization is the complete elimination of all forms of microbial life, including bacterial spores, viruses, fungi, and vegetative cells. Methods such as autoclaving, dry heat, radiation, and certain chemical sterilants are used for medical instruments and laboratory materials. Sterilization methods are extremely harsh and are not applied to living tissues.

D. disinfection: Disinfection involves the use of chemical or physical agents to destroy vegetative pathogens on inanimate objects such as medical equipment, countertops, and hospital surfaces. While effective against many microorganisms, disinfectants are typically too toxic or irritating to be used safely on living tissues.

E. degermation: Degermation refers to the mechanical removal of microorganisms from a limited area, usually through physical actions such as scrubbing or washing. While it reduces microbial numbers, it primarily involves mechanical removal rather than the direct chemical destruction of pathogens.

A. do not cause many human infections: While some fungi, protozoa, and helminths cause fewer infections compared to bacteria, the main limitation in drug development is not the frequency of infections. Even common infections like candidiasis or malaria require treatment, so infection prevalence alone does not explain the scarcity of effective drugs.

B. have fewer target sites compared to bacteria: These organisms do possess cellular structures that could be targeted, such as cell membranes, enzymes, or nucleic acids. The issue is not the number of potential targets but the similarity of those targets to human cells, which complicates drug design.

C. are so similar to human cells that selective drug toxicity is difficult to achieve: Fungi, protozoa, and helminths are eukaryotic, like human cells, meaning their cellular structures and metabolic pathways closely resemble those of the host. This similarity makes it challenging to develop drugs that are toxic to the pathogen but safe for human cells, limiting the number of available therapeutic options.

D. are parasites found inside human cells: While intracellular parasites pose delivery challenges for drugs, this is not the primary reason for the overall scarcity of antifungal, antiprotozoan, and antihelminth medications. Drug development is limited mainly by eukaryotic similarity rather than intracellular location alone.

E. are not affected by antimicrobics: This is incorrect because antifungal, antiprotozoan, and antihelminth drugs do exist and can be effective. The challenge is creating agents that selectively target these organisms without harming human cells, not an inherent resistance to all antimicrobial agents.