3.1 Microbiology, Pathogens & Modes of Transmission

Infection control starts with knowing what you are trying to stop. Pathogens are disease-causing organisms. In an Oklahoma salon they move from person to person on unwashed hands, shared implements, soiled towels, chairs, and blood or other potentially infectious material (OPIM). The National-Interstate Council of State Boards of Cosmetology (NIC) National Cosmetology Theory Examination tests cause and transmission of diseases and infections inside Scientific Concepts. Oklahoma Administrative Code (OAC) Title 175 adds a hard operational rule: if you have reason to suspect a communicable or infectious disease, you do not work around it. You stop, wash and disinfect your hands, and refer the patron to a physician (OAC 175:10-7-20).

This OpenExamPrep chapter teaches salon microbiology together with those Oklahoma stop-and-refer duties. It does not invent Oklahoma-specific infection rates. It does not claim official partnership with NIC or the Oklahoma State Board of Cosmetology and Barbering (OSBCB). You still need both vocabularies: scientific names on theory items, and Board verbs — stop, wash, refer, wipe, bag — on sanitation law.

Bacteria in the Salon

Bacteria are single-celled microorganisms. Many are nonpathogenic and live harmlessly on skin. Pathogenic bacteria cause infection. Salon-relevant shapes include cocci (round), bacilli (rod-shaped), and spirilla (spiral). Staphylococci cluster like grapes and are associated with abscesses, boils, and some skin infections. Streptococci form chains and are associated with strep throat and some skin infections. Diplococci appear in pairs.

Methicillin-resistant Staphylococcus aureus (MRSA) is a staphylococcus that does not respond to some common antibiotics. Teach it conceptually: it can colonize skin, hide in cuts, and travel on hands, clippers, tweezers, and linens that were not cleaned and then disinfected. A client may have no dramatic rash at first. That is why every multi-use tool is treated as contaminated after one patron, even when the skin looked intact. You will not diagnose MRSA in the chair. You will not skip disinfection because "the skin looked fine."

Some bacteria form spores — a dormant, protective state that can survive ordinary salon disinfection. The EPA-registered bactericidal, virucidal, and fungicidal products used on implements are not sold as sterilants that destroy every spore. Sterilization (for example, an autoclave used after disinfection) is the only category defined as destroying all microbial life, including spores. Oklahoma allows autoclave use only after disinfection, with periodic testing and maintenance per the manufacturer's instructions (OAC 175:10-7-5(i)).

Bacteria need moisture, a food source, and a suitable temperature. A wet towel left in a closed, unvented hamper, a pedicure basin with leftover skin debris, or a disinfectant pan full of hair and product residue is a growth-friendly environment. That is why Oklahoma requires soiled-linen containers to be covered and vented, and why immersion disinfectant must be changed daily or sooner if it is visibly contaminated. A cloudy, hairy soak pan is not "still working" — it is a contaminated soup.

Viruses in the Salon

Viruses are not cells. They must enter a living host cell to reproduce. Antibiotics do not kill viruses. Bloodborne viruses of salon concern include hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). HBV can remain infectious on environmental surfaces; a contaminated shear, razor, or nipper that nicks the next client is a classic indirect bloodborne route. HBV has a vaccine; HCV and HIV do not have the same routine occupational vaccine story. You are not a clinician confirming these infections. You are a licensee who treats every blood exposure as if those viruses could be present.

Herpes simplex virus (HSV) causes cold sores and other vesicular lesions. Direct contact with an active lesion, and contaminated implements or waxing supplies used around that lesion, can spread HSV. An active, weeping cold sore is a reason to postpone services that would contact the lesion. OAC 175:10-7-20(d) separately forbids massaging a surface that is inflamed or has open cuts, lesions, or infection. "I will just work around it" is not an Oklahoma-legal plan when the surface itself is open or infected.

Fungi (Tinea) and Parasites

Fungi that infect skin, hair, and nails live on keratin. Tinea is the ringworm group of fungal infections:

• Tinea capitis — scalp
• Tinea corporis — body
• Tinea pedis — feet (athlete's foot)
• Tinea unguium / onychomycosis — nails

These spread by direct contact and by fomites — shared towels, files that cannot be disinfected, shoes, and basins. A scaly, circular scalp patch with broken hairs is not dry dandruff you can oil and style through. It is a stop-and-refer presentation under the communicable-disease rule.

Parasites of exam importance are pediculosis capitis (head lice infestation) and scabies (itch mite, Sarcoptes scabiei). Pediculosis capitis is an animal infestation, not a fungus. That distinction is a classic theory trap: tinea capitis is fungal; tinea barbae is beard-area fungal infection; scabies is a mite; pediculosis capitis is lice. Scabies spreads by prolonged skin-to-skin contact and by infested towels, capes, and bedding. Intense itching, especially at night, with burrows in finger webs or on wrists, is not "sensitive skin that needs a hotter towel." Stop, wash, refer.

Oklahoma adds a specific lice protocol in OAC 175:10-7-7. You will see it again with blood-exposure procedures because both are stop-the-service events, not optional courtesy calls.

Modes of Transmission

OAC 175:10-7-20 requires universal precautions: treat blood and other body fluids/materials as if infectious. You do not wait for a lab result, a disclosure, or a dramatic amount of blood. You also do not continue a service because the client "just has a little something." If you suspect a communicable or infectious disease, wash and disinfect your hands, discontinue services, and refer to a physician. A person in charge who knows that a licensee, student, apprentice, or patron is infected must not allow that person to work or receive services in the establishment.

Head Lice: Oklahoma's Named Stop Protocol

If head lice is detected, do not proceed with further services. Wash and disinfect hands. Refer the person to a physician or health clinic. Before services resume, the person should submit a statement signed by a practicing physician stating they are no longer infected and free from a communicable episode. Wipe exposed areas with an EPA-registered lice-killing product. Seal exposed towels and other linen in a plastic bag until they can be laundered. The same immediate referral applies if lice or another communicable condition is found on a licensee, student, or apprentice. The owner/manager is responsible for keeping an infected person from performing services; noncompliance can bring license revocation or suspension (OAC 175:10-7-7).

Theory exams love swapping look-alike names. Clinic inspectors love seeing whether you actually stopped. Learn the organism, the route, and the Oklahoma action as one chain.