Microbiology, 2021

13.3 • Using Chemicals to Control Microorganisms 537
Figure 13.26 (a) Two common quats are benzylalkonium chloride and cetylpyrimidine chloride. Note the hydrophobic nonpolar carbon
chain at one end and the nitrogen-containing cationic component at the other end. (b) Quats are able to infiltrate the phospholipid plasma
membranes of bacterial cells and disrupt their integrity, leading to death of the cell.
CHECK YOUR UNDERSTANDING
• Why are soaps not considered disinfectants?
MICRO CONNECTIONS
Handwashing the Right Way
Handwashing is critical for public health and should be emphasized in a clinical setting. For the general
public, the CDC recommends handwashing before, during, and after food handling; before eating; before and
after interacting with someone who is ill; before and after treating a wound; after using the toilet or changing
diapers; after coughing, sneezing, or blowing the nose; after handling garbage; and after interacting with an
animal, its feed, or its waste. Figure 13.27 illustrates the five steps of proper handwashing recommended by
the CDC.
Handwashing is even more important for health-care workers, who should wash their hands thoroughly
between every patient contact, after the removal of gloves, after contact with bodily fluids and potentially
infectious fomites, and before and after assisting a surgeon with invasive procedures. Even with the use of
proper surgical attire, including gloves, scrubbing for surgery is more involved than routine handwashing. The
goal of surgical scrubbing is to reduce the normal microbiota on the skin’s surface to prevent the introduction
of these microbes into a patient’s surgical wounds.
There is no single widely accepted protocol for surgical scrubbing. Protocols for length of time spent scrubbing
may depend on the antimicrobial used; health-care workers should always check the manufacturer’s
recommendations. According to the Association of Surgical Technologists (AST), surgical scrubs may be
performed with or without the use of brushes (Figure 13.27).