Analysis of the Effect of Antimicrobial Soap on Bacterial Survival

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.