Analysis of the Effect of Antimicrobial Soap on Bacterial Survival
Condition: Survival of Bacteria on Skin After Using Different Soaps
Study type: Interventional

Summary: 
      This study will recruit up to 10 healthy volunteers. An avirulent strain of S. pyogenes will
      be applied to their forearms after washing each of their forearms with different types of
      soap, one with an antimicrobial compound, and the other without an antimicrobial compound.
      After several hours of incubation, the subject's forearms will be swabbed for bacteria. The
      forearms will then be cleansed with antibacterial soap and water followed by 70% ethanol. The
      bacterial swabs will be analyzed and compared between the different soaps that were used to
      cleanse each digit prior to the application of S. pyogenes. The investigator expects the
      number of bacteria surviving on the skin of forearms washed with antimicrobial soaps will be
      fewer than with control soap.
    

Detailed description: 
      The study timeline will be as follows:

      Day -7 to -1 - After obtaining informed consent, potential participants will be screened. A
      brief history and physical exam will be done on those who meet enrollment criteria. They will
      be assigned a start date to coincide with Day 0 below.

      Day 0 - Participants will be instructed not to shower on this day. They may shower the
      evening before Day 0, however starting at midnight on Day 0, the participant will be advised
      not to shower. They will also be asked to wear a shirt with long sleeves. Significant
      exercise, sunbathing, and the use of creams or lotions on the forearms should also be avoided
      starting on Day 0, and these restrictions will remain in place until all Day 1 study-related
      procedures are completed. In the late afternoon on this day, the subject will have six (6) 2
      cm x 2 cm squares drawn on each forearm using a skin marker. The volar forearms will be
      washed with soap, taking care to not remove the skin markings. One forearm will be washed
      with a soap containing an antibacterial compound. The other forearm will be washed using a
      control soap that does not contain an antibacterial compound. Each washing will consist of
      the application of 1.5 mL of test product to the volar forearm. A lather will be generated
      for 20 seconds using a gloved hand. The forearm will be rinsed with running tap water for 30
      seconds and allowed to air-dry. Each forearm will be wrapped in gauze once dry. The gauze
      should be kept dry and in place until removed by the study staff the following day.

      Day 1 - On the morning of Day 1, the gauze will be removed from participants' forearms, and
      10 µL PBS containing 104 CFU of avirulent Streptococcus pyogenes (strain NZ131 M49) will be
      applied to the center of each of the squares previously drawn on participants' forearms. The
      bacteria will be spread within each square to evenly coat the surface of the skin within the
      square. The bacteria will then be allowed to air dry. Once dry, skin swabs will be rubbed
      over two of the squares on each forearm to collect a sample of the bacteria on the forearm at
      that location. After swabbing, these areas will be immediately disinfected with 70% alcohol.
      The forearms will then be wrapped again in gauze. One hour later, the gauze will be removed,
      and two more squares on each forearm will be swabbed for bacteria. These squares will then be
      disinfected with 70% alcohol, and gauze reapplied to the forearms. One hour later (two hours
      post-washing), the gauze will be removed, and the remaining two squares on each forearm will
      be swabbed for bacteria. Both forearms will then be washed with 70% ethanol and rinsed with
      water to remove any remaining bacteria. This will conclude the study-related procedures for
      Day 1. Participants are then free to shower, sunbathe, exercise and apply any creams or
      lotions to their forearms until the following week.

      These same study procedures as above will be repeated again on Days 7 and 8, however the
      antibacterial soap will be used to wash one of the forearms will be replaced by a different
      antibacterial soap. The exact details are described in the paragraphs below.

      Day 7 - Participants will be instructed not to shower on this day. They may shower the
      evening before Day 7, however starting at midnight on Day 7, the participant will be advised
      not to shower. They will also be asked to wear a shirt with long sleeves. Significant
      exercise, sunbathing, and the use of creams or lotions on the forearms should also be avoided
      starting on Day 7, and these restrictions will continue until all Day 8 study-related
      procedures are completed. In the late afternoon on this day, the subject will have six (6) 2
      cm x 2 cm squares drawn on each forearm using a skin marker. The volar forearms will be
      washed with soap, taking care to not remove the skin markings. One forearm will be washed
      with a soap containing an antibacterial compound. The other forearm will be washed using a
      control soap that does not contain an antibacterial compound. Each washing will consist of
      the application of 1.5 mL of test product to the volar forearm. A lather will be generated
      for 20 seconds using a gloved hand. The forearm will be rinsed with running tap water for 30
      seconds and allowed to air-dry. Each forearm will be wrapped in gauze once dry. The gauze
      should be kept dry and in place until removed by the study staff the following day.

      Day 8 - On the morning of Day 8, the gauze will be removed from participants' forearms, and
      10 µL PBS containing 104 CFU of avirulent Streptococcus pyogenes (strain NZ131 M49) will be
      applied to the center of each of the squares previously drawn on participants' forearms. The
      bacteria will be spread within each square to evenly coat the surface of the skin within the
      square. The bacteria will then be allowed to air dry. Once dry, skin swabs will be rubbed
      over two of the squares on each forearm to collect a sample of the bacteria on the forearm at
      that location. After swabbing, these areas will be immediately disinfected with 70% alcohol.
      The forearms will then be wrapped again in gauze. One hour later, the gauze will be removed,
      and two more squares on each forearm will be swabbed for bacteria. These squares will then be
      disinfected with 70 alcohol, and gauze reapplied to the forearms. One hour later (two hours
      post-washing), the gauze will be removed, and the remaining two squares on each forearm will
      be swabbed for bacteria. Both forearms will then be washed with 70% ethanol and rinsed with
      water to remove any remaining bacteria. This will conclude all study-related procedures.
      Participants are then free to shower, sunbathe, exercise and apply any creams or lotions to
      their forearms.
    

Intervention name(s): Antibacterial soap with triclocarban; Antibacterial soap + benzalkonium chloride; Control soap
Intervention type(s): Other; Other; Other
Intervention MeSH terms: Anti-Bacterial Agents; Benzalkonium Compounds; Triclocarban
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: bacteria survival, surfactants