Outcomes of the 2014 SPAUD meeting

Reprinted from the SPAUD website

A publication based on the information presented and discussed at SPAUD is in progress. The following are a few top line highlights from the meeting.

• The use of antibiotics in livestock feed comprises almost 80% of total antibiotic use in the US.¹ Antibiotic resistant bacterial strains as well as antibiotics themselves gain access to wastewater from livestock and poultry farms.

• The addition of antibiotics to livestock feed may alter the microbial ecology, can contribute to emergence of infections in humans, and can increase carriage of resistant bacteria. For example, 30% of workers employed at farms using tetracycline in animal feed were positive nasal carriers of tetracycline-resistant MRSA nasal colonization as compared to 2% of workers employed at antibiotic-free farms.² In addition, a specific MRSA strain induced in hogs fed with tetracycline has subsequently been recovered from human infection, and has been found in 30% of tested supermarket beef and pork (30%), and on 10% of shopping cart handles.³ 

​RELATED: Partnering with pharmacists in responsible prescribing

• Human use of antibiotics represents 19.1% of annual antibiotic use in the US.¹ The most commonly prescribed oral antibiotics among all US clinicians in 2010  were azithromycin (166 Rx per 1000 persons), amoxicillin (166 Rx per 1000 persons), amoxicillin-clavulanate (70 Rx per 1000 persons), ciprofloxacin (66 Rx per 1000 persons), and cephalexin (65 Rx per 1000 persons).^4,5 When prescribing patterns of a specific antibiotic lead to a high prevalence of emergence of an antibiotic-resistant pathogenic bacteria, studies have shown that altering prescribing of the antibiotic can reduce the antibiotic resistance rate.^6,7 

• Much of the data evaluating the sensitivity of Propionibacterium acnes to various antibiotics such as the tetracyclines and clindamycin is based on studies that were completed ten to fifteen years ago. More recent data shows increasing levels of less sensitive strains to commonly used antibiotics, with geographic variations correlating with the frequency of use of specific antibiotics.^8-11 Over time, some strains of P. acnes have become much less sensitive to clindamycin, which appears reduce efficacy in patients with acne vulgaris who harbor a high population of these less sensitive organisms.

RELATED: 3 things derms can do now to limit antibiotic use

• Oral isotretinoin induces cutaneous changes that alter the microbial flora. The microbial effects include reduction in P. acnes, decrease in surface Gram-negative bacteria, and increase in S. aureus colonization.¹²

• MRSA continues to be a common cause of cutaneous infection encountered in outpatient clinics, including dermatology. Updated practice guidelines for the management of skin and soft tissue infections from the Infectious Disease Society of America have been published in 2014.¹³

RELATED: The pendulum is swinging

References

1. Hollis A, Ahmed Z. Preserving antibiotics, rationally. N Engl J Med. 2013:369:2474-2476.

2. Rinsky JL, Nadimpalli M, Wing S, et al. Livestock-associated methicillin and multidrug resistant Staphylococcus aureus is present among industrial, not antibiotic-free livestock operation workers in North Carolina. PLoS One. 2013 Jul 2;8(7):e67641.

3. Mole B. MRSA: Farming up trouble. Nature. 2013. 25;499(7459):398-400.

4. Sanchez G. Get smart: know when antibiotics work. American Acne and Rosacea Society And Scientific Panel on Antibiotic Use in Dermatology Meeting, Las Vegas, NV, September 6, 2014.

5. IMX Xponent Data, 2011.

6. Seppälä H, Klaukka T, Vuopio-Varkila J, et al. The effect of changes in the consumption of macrolide antibiotics on erythromycin resistance in group A streptococci in Finland. Finnish study group for antimicrobial resistance. N Engl J Med. 1997;14;337(7):441-446.

7. Cristino MJ. Correlation between consumption of antimicrobials in humans and development of resistance in bacteria. Int J Antimicrob Agents. 1999;12:199-202.

8. Bowe WP, Leyden JJ. Clinical implications of antibiotic resistance: risk of systemic infection from Staphylococcus and Streptococcus. In: Shalita AR, Del Rosso JQ, Webster GF, Eds. Acne Vulgaris, Informa healthcare, London, UK, 2011, pp 125-133.

9. Leyden JJ, Del Rosso JQ, Webster GF. Clinical considerations in the treatment of acne vulgaris and other inflammatory skin disorders: focus on antibiotic resistance. Cutis. 2007;79(suppl 6):9-25.

10. Del Rosso JQ, Leyden JJ, Thiboutot D, Webster GF. Antibiotic use in acne vulgaris and Rosacea: clinical considerations and resistance issues of significance to dermatologists. Cutis. 2008;82(suppl 2[ii]):5-12.

11. Levy RM, Huang EY, Roling D, et al. Effect of antibiotics on the oropharyngeal flora in patients with acne. Arch Dermatol. 2003;139(4):467-471.

12. James W, Leyden JJ. Treatment of gram-negative folliculitis with isotretinoin: positive clinical and microbiologic response. J Am Acad Dermatol. 1985:12:319-324.

13. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the infectious diseases society of America. Clin Infect Dis. 2014;59(2):147-159.