A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study
© Misner; licensee BioMed Central Ltd. 2007
Received: 14 June 2007
Accepted: 13 July 2007
Published: 13 July 2007
Athlete's Foot (Tinea pedis) is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Enclosing feet in socks and shoes generates a moisture-rich environment that stimulates overgrowth of pungent both aerobic bacteria and infectious yeast-fungi. Suppression of microbial growth may be accomplished by exposing the feet to air to enhance evaporation to reduce moistures' growth-stimulating effect and is often neglected. There is an association between yeast-fungi overgrowths and disabling foot infections. Potent agents virtually exterminate some microbial growth, but the inevitable presence of infection under the nails predicts future infection. Topical antibiotics present a potent approach with the ideal agent being one that removes moisture producing antibacterial-antifungal activity. Severe infection may require costly prescription drugs, salves, and repeated treatment.
A 63-y female volunteered to enclose feet in shoes and socks for 48 hours. Aerobic bacteria and yeast-fungi counts were determined by swab sample incubation technique (1) after 48-hours feet enclosure, (2) after washing feet, and (3) after 8-hours socks-shoes exposure to a aromatic oil powder-compound consisting of arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil.
Application of this novel compound to the external surfaces of feet completely inhibited both aerobic bacteria and yeast-fungi-mold proliferation for 8-hours in spite of being in an enclosed environment compatible to microbial proliferation. Whether topical application of this compound prevents microbial infections in larger populations is not known. This calls for more research collected from subjects exposed to elements that may increase the risk of microbial-induced foot diseases.
Kobayashi  isolated a gram-positive cocci bacterium from foot skin of 17 volunteers by swab sampling technique. This bacterium was identified as Staphylococcus epidermidis. Except for this unique staphylococcal species, microbes isolated from the athlete's foot infections are typically colonies of yeast-fungi. There are 700 known classified yeast-fungi, although their colonies often look like bacteria. Uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Athlete's Foot (Tinea pedis) is a form of ringworm associated with highly contagious colonies of Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and Trichophyton rubrum.
Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Hot weather, sweating, exercise, and shoes, generates a moisture-rich environment that stimulates overgrowth of both aerobic bacteria and yeast/fungi. The most harmful interdigital infections begin with invasion of the horny layer by dermatophytes. Large numbers of normally resident diphtheroids cause the common wet, macerated Athlete's Foot Syndrome (Tinea pedis), due to an overgrowth of gram-negative organisms. The dry, scaly type (dermatophytosis simplex) alternates with the wet, macerated type (dermatophytosis complex). Flare-ups are more common in summer and are experimentally induced by occlusion of fungus-infected feet. The pustular-mid sole form responds best to topical antifungal agents, while the interdigital form, responds to a mixed treatment of anti-fungal/anti-bacterial antibiotics, regular drying routine, and constant debridement. Toenail infections are caused by a variety of organisms, which may appear as onycholysis with or without paronychia and must also be treated with appropriate antibiotics. Since these microbes are part of the normal flora, infection often reoccurs, necessitating regular treatment . Suppression of microbial growth is accomplished by exposing the feet to air (e.g., wearing sandals) to enhance evaporation to reduce moistures' growth-stimulating effect. Drying is the decisive element and is often neglected. Topical antibiotics present a potent approach with the ideal agent being one that dries the skin by absorbing moisture and generating broad-spectrum antibacterial-antifungal activity. Potent agents virtually exterminate interdigital dermatophytes, but the inevitable presence of infection under the nails predicts future infection [14, 20]. There is an association between microbial overgrowth and disabling foot infections in athletes. Common skin microbes proliferate rapidly in a moisture-rich, enclosed environment resulting in limited or no athletic participation. Resolution of a severe infection may require prescription drugs, salves, or foot soakings. Arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil are also reported to inhibit both aerobic bacteria and yeast-mold-fungi growths respectively [1–7, 9–11, 13, 15–19, 21–23].
An aromatic oil powdered compound was selected for its broad-spectrum antibiotic effects on the feet of a single subject. The compound was selected to measure its combined antibiotic effect inhibiting aerobic bacteria or fungi/yeast cultures growing on the confined surfaces of the feet. A female volunteer stimulated the growth of common microbes by wearing socks and shoes for 48-hours without bathing or exposure to dry air. A significant increase in aerobic bacteria and yeast-fungi-mold concentrations were detected in the first incubated sample set. Application of the antibacterial-antifungal aromatic oil compound to feet reduced aerobic bacteria by a factor of 10,000 (from 100,000,000 to 10,000 per milliliter), and retained this suppressed number for 8 consecutive hours in spite of the subject's return to wearing socks and shoes. Furthermore, application of the antibacterial-antifungal aromatic oil compound to the feet surprisingly inhibited the yeast-fungi count by a factor of 100 (from 100,000 to 1000 per milliliter), and retained this suppressed number for 8 consecutive hours in spite of the subject's return to wearing socks and shoes. The application of this compound was associated with a remarkable inhibition of time/moisture-induced microbial overgrowth in this subject's feet.
Biosan Laboratories microbial test kits were utilized to sample and determine aerobic bacteria (AB) and yeast-fungi-mold (YFM) counts by an incubation procedure. A single female subject (63 y) enclosed feet in socks and shoes without bathing, without exposure to air for 48-hours. Three sets of 2 swab samples were extracted between-toes and subsequently incubated @ 25°–30°C (77–86°F) to determine the numerical count of aerobic bacteria and yeast-fungi/mold in the following samples:
1. Aerobic Bacteria & Yeast-Fungi count enclosed environment 48-hours no bathing
2. Aerobic Bacteria & Yeast-Fungi count immediately after washing with soapy water, drying, and application of arrowroot, baking soda, basil oil, bay oil, tea tree oil, sage oil, and clove oil powder
3. Aerobic Bacteria & Yeast-Fungi count 8-hours wearing socks and shoes following application of arrowroot, baking soda, basil oil, bay oil, tea tree oil, sage oil, and clove oil powder return to for
AB & YF count before and after powder application
AEROBIC BACTERIA Per Milliliter
YEAST-FUNGI Per Milliliter
Pre-Test 48-Hours Enclosed (in socks & shoes) No air, No Bathing
Immediately After Bathing & Powder Compound Application
Eight-Hours After Powder Compound Application Feet Enclosed (in socks & shoes)
Application of this novel herbal powdered compound to the external surfaces of feet inhibited overgrowth of aerobic bacteria and yeast-fungi-mold immediately, and continued to limit microbial proliferation for 8-hours. Whether topical application of this compound prevents microbial infections in larger populations is not known. This calls for more research collected from subjects exposed to elements that may increase the risk of microbial-induced foot diseases.
The author expresses appreciation to Cozy Bear Natural Products, PO Box 1105, Chewelah, Washington 99109, 509-937-2699, for their gracious donation of a herbal powdered compound selected for its ingredients contents, consisting of arrowroot, baking soda, basil oil, bay oil, tea tree oil, sage oil, and clove oil, (under the proprietary name "Sweet Feet") for this project.
- Ahmad N, Alam MK, Shehbaz A, Khan A, Mannan A, Hakim SR, Bisht D, Owais M: Antimicrobial activity of clove oil and its potential in the treatment of vaginal candidiasis. J Drug Target. 2005, 13 (10): 555-61. 10.1080/10611860500422958.View ArticlePubMedGoogle Scholar
- Amigoni NA, Johnson GK, Kalkwarf KL: The use of sodium bicarbonate and hydrogen peroxide in periodontal therapy: a review. J Am Dent Assoc. 1987, 114 (2): 217-21.View ArticlePubMedGoogle Scholar
- Bagamboula CF, Uyttendaele M, Debevere J: Antimicrobial effect of spices and herbs on Shigella sonnei and Shigella flexneri. J Food Prot. 2003, 66 (4): 668-673.PubMedGoogle Scholar
- Briozzo J, Núñez L, Chirife J, Herszage L, D'Aquino M: Antimicrobial activity of clove oil dispersed in a concentrated sugar solution. J Appl Bacteriol. 1989, 66 (1): 69-75.View ArticlePubMedGoogle Scholar
- Cervenka L, Peskova I, Foltynova E, Pejchalova M, Brozkova I, Vytrasova J: Inhibitory effects of some spice and herb extracts against Arcobacter butzleri, A. cryaerophilus, and A. skirrowii. Curr Microbiol. 2006, 53 (5): 435-9. 10.1007/s00284-006-0244-x.View ArticlePubMedGoogle Scholar
- Chiang LC, Ng LT, Cheng PW, Chiang W, Lin CC: Antiviral activities of extracts and selected pure constituents of Ocimum basilicum. Clin Exp Pharmacol Physiol. 2005, 32 (10): 811-816. 10.1111/j.1440-1681.2005.04270.x.View ArticlePubMedGoogle Scholar
- Christoph F, Kaulfers PM, Stahl-Biskup E: A comparative study of the in vitro antimicrobial activity of tea tree oils s.l. with special reference to the activity of b-triketones. Planta Medica. 2000, 66 (6):Google Scholar
- Conklin RJ: Common cutaneous disorders in athletes. Sports Med. 1990, 9 (2): 100-19.View ArticlePubMedGoogle Scholar
- Curran DM, Montville TJ: Bicarbonate inhibition of Saccharomyces cerevisiae and Hansenula wingei growth in apple juice. Int J Food Microbiol. 1989, 8 (1): 1-9. 10.1016/0168-1605(89)90074-3.View ArticlePubMedGoogle Scholar
- Hammer KA, Carson CF, Riley TV: In vitro activity of Melaleuca alternifolia (tea tree) oil against dermatophytes and other filamentous fungi. J Antimicrob Chemother. 2002, 50 (2): 195-199. 10.1093/jac/dkf112.View ArticlePubMedGoogle Scholar
- Kim S, Fung DY: Antibacterial effect of water-soluble arrowroot (Puerariae radix) tea extracts on foodborne pathogens in ground beef and mushroom soup. J Food Prot. 2004, 67 (9): 1953-6.PubMedGoogle Scholar
- Kobayashi S: [Relationship between an offensive smell given off from human foot and Staphylococcus epidermidis]. Nippon Saikingaku Zasshi. 1990, 45 (4): 797-800.View ArticlePubMedGoogle Scholar
- Lea P, Ding SF, Lemez SB: Ultrastructure changes induced by dry film formation of a trisodium phosphate blend, antimicrobial solution. Scanning. 2003, 25 (6): 277-84.View ArticlePubMedGoogle Scholar
- Leyden JJ, Kligman AM: Interdigital athlete's foot: new concepts in pathogenesis. Postgrad Med. 1977, 61 (6): 113-6.PubMedGoogle Scholar
- Matan N, Rimkeeree H, Mawson AJ, Chompreeda P, Haruthaithanasan V, Parker M: Antimicrobial activity of cinnamon and clove oils under modified atmosphere conditions. Int J Food Microbiol. 107 (2): 180-5. 10.1016/j.ijfoodmicro.2005.07.007. Epub 2005 Nov 2, 2006 Mar 15Google Scholar
- Ozcan MM, Sagdic O, Ozkan G: Inhibitory effects of spice essential oils on the growth of Bacillus species. J Med Food. 2006, 9 (3): 418-21. 10.1089/jmf.2006.9.418.View ArticlePubMedGoogle Scholar
- Pena EF: Melaleuca alternifolia oil. Its use for trichomonal vaginitis and other vaginal infections. Obstet Gynecol. 1962, 19: 793-795.PubMedGoogle Scholar
- Raharivelomanana PJ, Terrom GP, Bianchini JP, Coulanges P: [Study of the antimicrobial action of various essential oils extracted from Malagasy plants. II: Lauraceae]. Arch Inst Pasteur Madagascar. 1989, 56 (1): 261-71.PubMedGoogle Scholar
- Raman A, Weir U, Bloomfield SF: Antimicrobial effects of tea-tree oil and its major components on Staphylococcus aureus, Staph. epidermidis and Propionibacterium acnes. Lett Appl Microbiol. 1995, 21 (4): 242-245.View ArticlePubMedGoogle Scholar
- Resnik SS, Lewis LA, Cohen BH: The athlete's foot. Cutis. 1977, 20 (3): 351-3, 355.PubMedGoogle Scholar
- Schnitzler P, Schon K, Reichling J: Antiviral activity of Australian tea tree oil and eucalyptus oil against herpes simplex virus in cell culture. Pharmazie. 2001, 56 (4): 343-347.PubMedGoogle Scholar
- Soylu EM, Soylu S, Kurt S: Antimicrobial activities of the essential oils of various plants against tomato late blight disease agent Phytophthora infestans. Mycopathologia. 2006, 161 (2): 119-28. 10.1007/s11046-005-0206-z.View ArticlePubMedGoogle Scholar
- Varel VH, Miller DN, Lindsay AD: Plant oils thymol and eugenol affect cattle and swine waste emissions differently. Water Sci Technol. 2004, 50 (4): 207-13.PubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.