Antibiotic & Antibacterial Resistance of Skin Bacteria from Users & Non- Users of Antibacterial Wash Products Eugene C. Cole, DrPH Brigham Young University Provo, Utah

Organization Study conducted through cooperative efforts of two applied research organizations: Study conducted through cooperative efforts of two applied research organizations: Applied Environmental, Inc., Cary, NC Applied Environmental, Inc., Cary, NC Restoration Sciences, LLC, Cary, NC Restoration Sciences, LLC, Cary, NC Study sponsored by: Study sponsored by: The Soap and Detergent Association, Washington, DC The Soap and Detergent Association, Washington, DC

Objective Investigate relationship between antibiotic and antibacterial resistance in human skin bacteria: Investigate relationship between antibiotic and antibacterial resistance in human skin bacteria: Staphylococcus aureus Staphylococcus aureus Coagulase-negative Staphylococcus sp. Coagulase-negative Staphylococcus sp. Isolated from forearm skin of persons routinely using or not using body washes and bath soaps containing, exclusively, either: triclosan or triclocarban. Isolated from forearm skin of persons routinely using or not using body washes and bath soaps containing, exclusively, either: triclosan or triclocarban.

Summary These study results discount the speculative claim that the use of antibacterial wash products contribute to the selection and propagation of drug-resistant bacteria on human skin. These study results discount the speculative claim that the use of antibacterial wash products contribute to the selection and propagation of drug-resistant bacteria on human skin.

Approach Randomized study with 210 qualified male and female participants >18 years Randomized study with 210 qualified male and female participants >18 years 70 that frequently use body wash products containing only Triclosan (TCS) 70 that frequently use body wash products containing only Triclosan (TCS) 70 that frequently use body wash products containing only Triclocarban (TCC) 70 that frequently use body wash products containing only Triclocarban (TCC) 70 that frequently wash, but do not use any antibacterial body wash products (Controls) 70 that frequently wash, but do not use any antibacterial body wash products (Controls)

Approach Users were defined as those using TCC or TCS wash products on a regular basis during the last 30 days for body washing. Users were defined as those using TCC or TCS wash products on a regular basis during the last 30 days for body washing. Exclusion criteria disqualified persons from participating: Exclusion criteria disqualified persons from participating: Antibiotic therapy within last 90 days Antibiotic therapy within last 90 days Use of topical skin medications, medicated shampoos, anti-acne products Use of topical skin medications, medicated shampoos, anti-acne products Employment in health care, day-care, or animal care Employment in health care, day-care, or animal care Frequent swimmer or hot tub user Frequent swimmer or hot tub user Routine exposure to solvents Routine exposure to solvents

Approach Home visits confirmed qualification Home visits confirmed qualification Forearm skin samples were collected: Forearm skin samples were collected: Composite swab sample of both forearms, using a 4 x 16 cm (64 cm 2 template) Composite swab sample of both forearms, using a 4 x 16 cm (64 cm 2 template) Lab processing by elution, plating on SBA and incubation for hours at 37 º C Lab processing by elution, plating on SBA and incubation for hours at 37 º C Colonies selected by criteria: morphology, pigmentation, texture, hemolysis, etc Colonies selected by criteria: morphology, pigmentation, texture, hemolysis, etc Presumptive ID by gram stain, catalase, coagulase Presumptive ID by gram stain, catalase, coagulase Confirmation by reference laboratory Confirmation by reference laboratory

Approach Antibiotic susceptibility performed by: Antibiotic susceptibility performed by: Standard MIC testing using MicroScan method Standard MIC testing using MicroScan method Testing conducted by LabCorp, NC Testing conducted by LabCorp, NC Antibacterial susceptibility performed by: Antibacterial susceptibility performed by: Standard broth micro-dilution method (Barry et al, 1999), adapted from NCCLS method M7-A4 (NCCLS, 1997) Standard broth micro-dilution method (Barry et al, 1999), adapted from NCCLS method M7-A4 (NCCLS, 1997) All isolates tested against TCC and TCS All isolates tested against TCC and TCS All results verified through appropriate QA procedures and microorganism control strains All results verified through appropriate QA procedures and microorganism control strains

Approach Standard Antibiotic Susceptibility Panel: Standard Antibiotic Susceptibility Panel: Ampicillin Ampicillin Ciprofloxacin Ciprofloxacin Clindamycin Clindamycin Erythromycin Erythromycin Nitrofurantoin Nitrofurantoin Oxacillin Penicillin Tetracycline TMP/SMX Vancomycin

Results 317 Staphylococcus isolates 317 Staphylococcus isolates 301 CNS isolates 301 CNS isolates Non-users (n = 106) Non-users (n = 106) TCC users (n = 102 TCC users (n = 102 TCS users (n = 93) TCS users (n = 93) 16 SA isolates 16 SA isolates Non-users (n = 4) Non-users (n = 4) TCC users (n = 7) TCC users (n = 7) TCS users (n = 5) TCS users (n = 5)

Results No isolates showed full or intermediate resistance to vancomycin No isolates showed full or intermediate resistance to vancomycin S. aureus - MRSA S. aureus - MRSA Rates of resistance to oxacillin was less than reported rates for hospital- acquired and community-acquired MRSA: Rates of resistance to oxacillin was less than reported rates for hospital- acquired and community-acquired MRSA: 12.5% 12.5% 20.2% (Fridkin et al, 2002) 20.2% (Fridkin et al, 2002) 50.0% (Tiemersma et al, 2004) 50.0% (Tiemersma et al, 2004)

Results CNS - MR CNS - MR Rates of resistance to oxacillin was less than reported rates for hospital-acquired and community- acquired MR-CNS: Rates of resistance to oxacillin was less than reported rates for hospital-acquired and community- acquired MR-CNS: 20.6% 20.6% 43.6% (Fridkin et al, 2002) 43.6% (Fridkin et al, 2002) 73.3% (DUMC, 2005) 73.3% (DUMC, 2005)

Results MRSA MRSA NU = 25.0% (1/4) NU = 25.0% (1/4) TCC = 0.0% (0/7) TCC = 0.0% (0/7) TCS = 20.0% (1/5) TCS = 20.0% (1/5) MR-CNS MR-CNS NU = 17.9% (19/106) NU = 17.9% (19/106) TCC = 23.5% (24/102) TCC = 23.5% (24/102) TCS = 20.4% (19/93) TCS = 20.4% (19/93)

Results Antibiotic Resistance - SA Antibiotic Resistance - SA Distribution across all 10 drugs showed no significant differences among groups, even when TCC and TCS data were pooled and compared with NU results. Distribution across all 10 drugs showed no significant differences among groups, even when TCC and TCS data were pooled and compared with NU results. Distribution across the 6 preferred drugs showed no significant differences among groups, even when TCC and TCS data were pooled and compared with NU results. Distribution across the 6 preferred drugs showed no significant differences among groups, even when TCC and TCS data were pooled and compared with NU results.

Results Antibiotic Resistance - CNS Antibiotic Resistance - CNS Distribution across all 10 drugs showed no significant differences among groups, even when TCC and TCS data were pooled and compared with NU results. Distribution across all 10 drugs showed no significant differences among groups, even when TCC and TCS data were pooled and compared with NU results. Greater tetracycline resistance in NU group isolates. Greater tetracycline resistance in NU group isolates.

Results Antibiotic Resistance to more than 1 preferred drug Antibiotic Resistance to more than 1 preferred drug CNS - for 69 isolates, rates of resistance for each of the 3 groups were comparable CNS - for 69 isolates, rates of resistance for each of the 3 groups were comparable NU = 25.5% (27/106) NU = 25.5% (27/106) TCC = 24.5% (25/102) TCC = 24.5% (25/102) TCS = 18.3% (17/93) TCS = 18.3% (17/93)

Results Antibiotic Resistance to more than 1 preferred drug Antibiotic Resistance to more than 1 preferred drug SA - for 2 isolates, rates of resistance for each of the 3 groups were comparable SA - for 2 isolates, rates of resistance for each of the 3 groups were comparable NU = 25.0% (1/4) NU = 25.0% (1/4) TCC = 00.0% (0/7) TCC = 00.0% (0/7) TCS = 20.0% (1/5) TCS = 20.0% (1/5)

Results Antibacterial (TCC/TCS) Resistance Antibacterial (TCC/TCS) Resistance All isolates (n=317) were tested for resistance to TCC and TCS All isolates (n=317) were tested for resistance to TCC and TCS CNS isolates from all 3 groups had comparable MIC values when tested against TCC and TCS CNS isolates from all 3 groups had comparable MIC values when tested against TCC and TCS SA isolates had comparable MIC values when tested against TCC and TCS SA isolates had comparable MIC values when tested against TCC and TCS

Results Antibacterial Resistance Antibacterial Resistance CNS – MIC Values TCC TCS NU TCC TCS

Results Antibacterial Resistance Antibacterial Resistance SA – MIC Values TCC TCS NU TCC TCS

Results Cross-Resistance Testing Cross-Resistance Testing CNS – 9 isolates most resistant to preferred treatment drugs (4-5) CNS – 9 isolates most resistant to preferred treatment drugs (4-5) Antibacterial MICs for TCC were comparable across all 3 groups, with none showing highest MICs (as did less antibiotic-resistant isolates) Antibacterial MICs for TCC were comparable across all 3 groups, with none showing highest MICs (as did less antibiotic-resistant isolates) MICs for TCS were comparable, and with one exception, none showed highest MICs (as did less antibiotic- resistant isolates) MICs for TCS were comparable, and with one exception, none showed highest MICs (as did less antibiotic- resistant isolates)

Results Cross-Resistance Testing Cross-Resistance Testing CNS – 7 isolates w/highest antibacterial MICs for TCC CNS – 7 isolates w/highest antibacterial MICs for TCC Comparable antibiotic resistance across the 3 groups (resistance to 0-2 preferred drugs), as opposed to resistance to 4-5 drugs shown by less TCC-resistant isolates. Comparable antibiotic resistance across the 3 groups (resistance to 0-2 preferred drugs), as opposed to resistance to 4-5 drugs shown by less TCC-resistant isolates.

Results Cross-Resistance Testing Cross-Resistance Testing CNS – 60 isolates w/highest antibacterial MICs for TCS CNS – 60 isolates w/highest antibacterial MICs for TCS Comparable antibiotic resistance across the 3 groups, as opposed to resistance to drugs shown by less TCS-resistant isolates. Comparable antibiotic resistance across the 3 groups, as opposed to resistance to drugs shown by less TCS-resistant isolates.

Results Cross-Resistance Testing Cross-Resistance Testing SA SA No isolates showing highest possible MIC value for TCC. No isolates showing highest possible MIC value for TCC. Of 3 isolates showing the highest MIC value for TCS, none were resistant to any of the preferred treatment drugs. Of 3 isolates showing the highest MIC value for TCS, none were resistant to any of the preferred treatment drugs.

Conclusion These study results confirm similar findings from recent assessments of antibiotic and antibacterial resistance in home environments These study results confirm similar findings from recent assessments of antibiotic and antibacterial resistance in home environments Cole et al, J Appl Micro 2003 Aiello et al, Emer Inf Dis 2005 Cole et al, J Appl Micro 2003 Aiello et al, Emer Inf Dis 2005

Conclusion These study results further discount the speculative claim that the use of antibacterial wash products contribute to the selection and propagation of drug-resistant bacteria on human skin. These study results further discount the speculative claim that the use of antibacterial wash products contribute to the selection and propagation of drug-resistant bacteria on human skin.

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