3.1 Bacteria: Types, Growth & Infections in Nail Services

Quick Answer: Bacteria are one-celled microorganisms. Nonpathogenic bacteria are harmless. Pathogenic bacteria cause disease, and they are what disinfection and hand cleaning target. The three shapes are cocci (round), bacilli (rods) and spirilla (spirals). Cocci group as staphylococci (clusters, pus-forming), streptococci (chains) and diplococci (pairs). Bacteria multiply by binary fission in warm, damp, dirty conditions. Some bacilli form spores that only sterilization can destroy. Green discoloration under a lifted enhancement is a bacterial infection, usually Pseudomonas aeruginosa, not mold.

Why Microbiology Is on a Nail Exam

Nail services involve implements used near living tissue, soaking basins, shared tables and dust from filing. Microorganisms spread from one client to the next through direct contact (skin to skin), indirect contact through contaminated objects (called fomites, such as nippers, files, towels and foot spas), and airborne droplets or dust. The Safety, Sanitation & Infection Control domain is 40% of the Written Theory exam, and "types of bacteria" is one of its listed topics.

Pathogenic vs. Nonpathogenic

• Nonpathogenic bacteria are harmless and often useful. They make up the majority of bacterial species. Some are saprophytes that live on dead matter and help decomposition, and normal skin flora helps crowd out harmful organisms.
• Pathogenic bacteria are harmful and cause disease when they invade tissue, multiply and produce toxins. Every sanitation rule you learn exists to break their chain of transmission.

The Three Shapes

The Three Cocci Groups

• Staphylococci: pus-forming cocci in grape-like clusters. They cause abscesses, pustules and boils. Staphylococcus aureus includes MRSA (methicillin-resistant S. aureus), which resists common antibiotics. MRSA often starts as a small red bump that looks like a pimple or insect bite.
• Streptococci: pus-forming cocci in chains, like a string of beads. They cause strep throat, impetigo, cellulitis and blood poisoning.
• Diplococci: cocci in pairs. They cause pneumonia.

Motility: cocci rarely move on their own. Bacilli and spirilla are motile, using hair-like flagella (older texts also mention cilia) to move through liquid.

How Bacteria Grow and Reproduce

Bacteria have two stages:

1. Active (vegetative) stage. The bacteria grow and reproduce. They thrive where it is warm, dark, damp and dirty, for example in debris trapped under a foot spa screen, in a damp towel or on an uncleaned implement. When a cell reaches full size it divides in two by binary fission. Under ideal conditions this can happen every 20–30 minutes, so one cell can become millions in a few hours.
2. Inactive (spore-forming) stage. When conditions turn harsh, such as heat, cold, drying out or lack of food, certain bacilli (Bacillus and Clostridium species, including the cause of tetanus) form tough spores. Spores resist heat, drying and ordinary disinfectants. They become active again when conditions improve. Only sterilization destroys spores. In Kansas regulations, sterilization means a steam autoclave or dry-heat sterilizer, and ultraviolet light is not an acceptable form of sterilization (K.A.R. 28-24-1(s)).

Bacterial Infections

• Inflammation is the body's response to injury or infection. Its signs are redness, heat, pain and swelling.
• Pus is a fluid of white blood cells, dead cells, bacteria and debris. Pus is a sign of bacterial infection.
• A local infection stays in one area, such as a pustule, boil or infected hangnail.
• A general (systemic) infection spreads through the bloodstream to the whole body, for example blood poisoning.
• A disease is contagious (communicable) when it spreads from one person to another by contact.

Kansas regulations treat open sores and inflamed tissue suggesting a communicable disease or condition as reasons not to provide a service until a physician signs a statement that the condition is no longer contagious (K.A.R. 28-24-3; section 3.3).

Pseudomonas: The "Greenies" Under Enhancements

Clients sometimes return with a yellow-green to dark green or black stain on the natural nail under a lifted acrylic, gel or wrap. Salon slang calls it "mold," but mold does not grow on the nail plate. The stain comes from a bacterial infection, most often Pseudomonas aeruginosa. This bacterium thrives in the warm, damp pocket that forms when product lifts and water gets trapped. As it grows it produces pigments (pyocyanin, blue-green, and pyoverdine, yellow-green) that stain the nail plate. The color darkens as the infection progresses.

What to do:

1. Do not apply new product, polish or a tip over the discolored nail. Sealing the pocket makes things worse.
2. Remove the lifted product with the correct soak-off method (section 9.7). Do not pry it off.
3. Treat all multi-use implements that touched the nail as soiled, clean and disinfect them, and discard files and buffers.
4. Explain the finding without diagnosing, and refer the client to a physician. Signs of infection such as swelling, pain or pus mean the service stops.
5. Prevention: prep correctly, never leave lifting unrepaired at fills, and tell clients to come back promptly if product lifts.

Biofilms

A biofilm is a colony of microorganisms stuck to a wet surface and wrapped in a slimy protective layer. Biofilms build up in pedicure pipes, jets, screens and drains when debris is left behind. Microbes inside a biofilm are far harder to kill than free-floating ones, so disinfectant alone does not work. The surface must first be scrubbed clean to break the film, and then disinfected. This is why Kansas pedicure rules require removing parts and scrubbing every surface before disinfecting (section 8.5). In 2000, one California salon's whirlpool foot baths caused skin infections in more than 100 clients. The cause was Mycobacterium fortuitum growing in debris behind the inlet screens.

Breaking the Chain of Infection

Each step of your routine blocks one route of transmission: