# Presentation: 528806

## 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:
- Applied Environmental, Inc., Cary, NC
- Restoration Sciences, LLC, Cary, NC
- Study sponsored by:
- The Soap and Detergent Association, Washington, DC

## Objective

- Investigate relationship between antibiotic and antibacterial resistance in human skin bacteria:
***Staphylococcus aureus***
**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**.

## 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.**

## Approach

**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 **Triclocarban** (TCC)
- 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.**
**Exclusion criteria disqualified persons from participating:**
**Antibiotic therapy within last 90 days**
**Use of topical skin medications, medicated shampoos, anti-acne products**
**Employment in health care, day-care, or animal care**
**Frequent swimmer or hot tub user**
**Routine exposure to solvents **

## Approach

**Home visits confirmed qualification**
**Forearm skin samples were collected:**
**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 18-24 hours at 37****o**** C **
- Colonies selected by criteria: morphology, pigmentation, texture, hemolysis, etc
- Presumptive ID by gram stain, catalase, coagulase
- Confirmation by reference laboratory

## Slide 8

## Approach

**Antibiotic susceptibility performed by:**
**Standard MIC testing using MicroScan method**
**Testing conducted by LabCorp, NC**
**Antibacterial susceptibility performed by:**
**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 results verified through appropriate** QA procedures and microorganism control strains

## Approach

- Standard Antibiotic Susceptibility Panel:
**Ampicillin**
**Ciprofloxacin**
**Clindamycin**
**Erythromycin**
**Nitrofurantoin**

**Oxacillin**
**Penicillin**
**Tetracycline**
**TMP/SMX**
**Vancomycin**

## Results

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

## Results

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

## Results

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

## Results

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

## Results

**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 **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**
- 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**.

## Results

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

## Results

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

## Results

**Antibacterial (TCC/TCS) Resistance**
- 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**
**SA isolates had comparable MIC values when tested against TCC and TCS**

## Results

**Antibacterial Resistance**
**CNS – MIC Values**
**	****	****	****TCC****	****	****	****	****  TCS**
**NU****	****0.0117-0.750****	****	****  0.128-2.020**
**TCC****	****0.0234-0.750****	****	****  0.004-2.020**
**TCS****	****0.0117-0.750****	****  ****	****  0.008-2.020**

## Results

**Antibacterial Resistance**
**SA – MIC Values**
**	****	****	****TCC****	****	****	****   ****	****   TCS**
**NU****	****0.0469-0.1875****	****    0.510-2.040**
**TCC****	****0.0029-0.1875****	****    0.124-1.020**
**TCS****	****0.0469-0.1875****	****    1.020-2.040**

## Results

**Cross-Resistance Testing**
**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) **
**MICs for TCS were comparable, and with one exception, none showed highest MICs (as did less antibiotic-resistant isolates)**

## Results

**Cross-Resistance Testing**
**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**.

## Results

**Cross-Resistance Testing**
**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.**

## Results

**Cross-Resistance Testing**
**SA**
**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.**

## Conclusion

**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 **

## 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.**

## References

- Cole et al, 20003, Investigation of antibiotic and antibacterial agent cross-resistance in target bacteria from homes of antibacterial product users and non-users.  *Journal of Applied Microbiology* 95:664-676.
- Aiello et al, 2005, Antibacterial cleaning products and drug resistance. *Emerging Infectious Diseases*, 11(10):1565-1570.
- DUMC (2005), Summary of Antimicrobial Susceptibility Test Results 1999-2004, Duke University Medical Center, Durham, NC, htpp://pathology.mc.duke.edu/microbiology/susceptibility.htm.
- Fridkin SF, Hill HA, Volkova NV, Edwards JR, Lawton RM, Gaynes RP, McGowan , Jr JE, 2002, Temporal changes in prevalence of antimicrobial resistance in 23 U.S. hospitals, *Emerging Infectious Diseases*, (8)7:697-701.
- Tiemersma EW, Bronzwaer SL, Lyytikainen O, Degener JE, Schrijnemakers P, Bruinsma N, Monen J, Witte W, Grundmann H, 2004,  Methicillin-resistant Staphylococcus aureus in Europe, 1999-2002, *Emerging Infectious Diseases*, 10(9):1627-1634.