Antimicrobial-antibiofilm compositions and methods of use thereof

Abstract

Compositions comprising chelating agents, metal ion salts, gelling agents or a buffer, antimicrobials, antibiofilm agents and a pH adjuster or a buffer for the prevention and treatment of wound infections and food-borne diseases involving bacterial biofilms are disclosed. The anti-infective properties of a composition include reduction or killing of anaerobic/aerobic/facultative gram-negative and gram-positive wound infection associated bacteria occurring in polymicrobial biofilms. The composition may be in the form of lotion, cream, ointment, dressing, bandage, rinse, soak, gel, spray, or other suitable forms, including certain devices. Additionally, the invention offers an efficient method of delivering the formulated composition containing one or two chelating agents or chelating agents alone or in combination with a metal ion salt using either a nanoparticle or other efficient delivery systems.

Claims

1. A composition for inhibiting biofilm formation caused by Malassezia pachydermatis, Staphylococcus aureus, or Malassezia furfur, the composition comprising: (a) EDTA salt at a concentration of about 0.5 mg/ml of the composition; and (b) sodium citrate at a concentration of between about 3.2 mg/ml to about 6.4 mg/ml of the composition.

2. The composition of claim 1, wherein the EDTA comprises disodium or tetrasodium EDTA.

3. The composition of claim 1, comprising: about 0.5 mg/ml EDTA salt and about 3.2 mg/ml sodium citrate.

4. The composition of claim 1, comprising: about 0.5 mg/ml EDTA salt and about 6.4 mg/ml sodium citrate.

5. The composition of claim 1, further comprising one or more ingredients selected from the group consisting of: water, a buffer, a stabilizing agent, a gelling agent, a surfactant, a herbal, a vitamin, a mineral, an extra cellular matrix, an antimicrobial, an antibiotic, and a pH adjuster.

6. The composition of claim 1 prepared as one or more of a disinfecting solution, a dip solution, a lotion, a cream, an ointment, a gel, a spray, a dressing, a gauze, a bandage, a thermoreversible gel spray, a wrap, an adhesive, a tape, a soak, a shampoo, and a balm.

7. The composition of claim 1, wherein the composition is delivered using a liposome or nanoparticle.

8. The composition as claimed in claim 1, further comprising an anti-infective compound selected from the group consisting of alginate lyase, nisin, lactoferricin, serotransferrin, ovotransferrin, ovalbumin, ovomucoid, protamine sulfate, chlorhexidine, cetylpyridinium chloride, triclosan, silver sulfadiazine, benzalkonium chloride, hydrogen peroxide, citric acid, potassium citrate, 5-fuorouracil, cis-2-decenoic acid, DNase I, proteinase K, silver, gallium, bacteriocins, antimicrobial peptides and an enzyme that cleaves poly-B-1,6-N-acetylglucosamine.

9. A method of preventing or treating wound infection, comprising topical or non-topical application of the composition of claim 1, wherein the wound infection is selected from one or more of infections of cuts, bruises, surgical sites, lacerations, abrasions, punctures, incisions, gunshots, burns, pyoderma, otitis media, otitis externa, otitis interna, cow udder mastitis, atopic dermatitis, eczema, pressure ulcers, venous and artery leg ulcers, and diabetic foot ulcers.

10. The method as set forth in claim 9, further comprising multiple applications of the composition.

11. The method as claimed in claim 9, wherein the method is used to treat one or more of humans, domestic animals, farm animals, zoo animals, pet animals, dogs, horses, cats, cattle, pigs, goats and sheep.

12. A method of preventing or treating meat spoilage comprising topical or non-topical use of the composition of claim 1 on meat or meat products.

13. A method of disinfecting meat comprising topical use of the composition of claim 1 on meat or meat products.

14. The method of claim 12, wherein the meat or meat products comprises intestine or intestinal parts of pigs, cattle, sheep, goats or horses used for making sausage casings.

15. A method of preventing or treating meat spoilage comprising topical or non-topical use of the composition of claim 1 on or impregnated into collagen or cellulose for making artificial sausage casings.

16. The method of claim 12, wherein the topical or non-topical use comprises one or more of coating, spraying, misting, injecting, soaking, flushing, dipping and rinsing.

17. A composition for inhibiting biofilm formation caused by Malassezia pachydermatis, Staphylococcus aureus,or Malassezia furfur, the composition comprising an antimicrobial agent consisting of: (a) EDTA salt at a concentration of about 0.5 mg/ml of the composition; and (b) citrate salt at a concentration of between more than about 3.2 mg/ml to about 6.4 mg/ml of the composition.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone and in combination on methicillin-resistant Staphylococcus aureus (MRSA) growth and biofilm formation.

(2) FIG. 2 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone and in combination on methicillin-resistant Staphylococcus pseudintermedius (MRSP) growth and biofilm formation.

(3) FIG. 3 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone and in combination on Pseudomonas aeruginosa growth and biofilm formation.

(4) FIG. 4 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.062 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone and in combination on Listeria monocytogenes growth and biofilm formation.

(5) FIG. 5 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2 and EDTA+ZnCl.sub.2 combinations on methicillin-resistant Staphylococcus aureus (MRSA) growth and biofilm formation.

(6) FIG. 6 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on methicillin-resistant Staphylococcus pseudintermedius (MRSP) growth and biofilm formation.

(7) FIG. 7 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml), and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Pseudomonas aeruginosa growth and biofilm formation.

(8) FIG. 8 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (025 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Salmonella choleraesuis ATCC 10708 growth and biofilm formation.

(9) FIG. 9 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Escherichia coli O157:H7 growth and biofilm formation.

(10) FIG. 10 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and in combination on Escherichia coli O157:H7 growth and biofilm formation.

(11) FIG. 11 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Staphylococcus epidermidis growth and biofilm formation.

(12) FIG. 12 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Coagulase-negative Staphylococci (CoNS-42) growth and biofilm formation.

(13) FIG. 13 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Streptococcus agalactiae ATCC 12386 growth and biofilm formation.

(14) FIG. 14 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Klebsiella pneumoniae growth and biofilm formation.

(15) FIG. 15 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Acinetobacter baumannii growth and biofilm formation.

(16) FIG. 16 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Stenotrophomonas maltophilia growth and biofilm formation.

(17) FIG. 17 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Vancomycin-resistant Enterococci (VRE) growth and biofilm formation.

(18) FIG. 18 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Enterococcus faecalis growth and biofilm formation.

(19) FIG. 19 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Proteus mirabilis growth and biofilm formation.

(20) FIG. 20 is a bar graph showing the inhibitory effect of sodium citrate (3 mg/ml), EDTA (0.25 mg/ml) and ZnCl.sub.2 (0.1 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Candida albicans growth and biofilm formation.

(21) FIG. 21 is a bar graph showing the inhibitory effect of sodium citrate (1.5 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.05 mg/ml) alone, and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations on Malassezia pachydermatis growth and biofilm formation.

(22) FIG. 22 is a bar graph showing the inhibitory effect of sodium citrate (1.5 mg/ml), EDTA (0.125 mg/ml) and ZnCl.sub.2 (0.05 mg/ml) alone and in combination on Malassezia pachydermatis growth and biofilm formation.

(23) FIG. 23 is a bar graph showing the inhibitory effect of sodium citrate (1.6 mg/ml), and EDTA (0.5 mg/ml) alone and in combination on Malassezia pachydermatis biofilm formation.

(24) FIG. 24 is a bar graph showing the inhibitory effect of sodium citrate (3.2 and 6.4 mg/ml), and EDTA (0.5 mg/ml) alone and in combination on Staphylococcus aureus biofilm formation.

(25) FIG. 25 is a bar graph showing the inhibitory effect of sodium citrate (3.2 and 6.4 mg/ml), and EDTA (0.5 mg/ml) alone and in combination on Malassezia furfur biofilm formation.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

(26) The term antimicrobial refers to a compound or a composition that kills or inhibits or stops the growth of microorganisms, including, but not limited to bacteria and yeasts.

(27) The term biofilm refers to a structured community of microorganisms enclosed in a self-produced extracellular polymeric matrix, and attached to a biotic or abiotic surface. Bacteria in a biofilm can be 1000 times more resistant to antibiotics/antimicrobials compared to their planktonic (free living) counterparts.

(28) The term biofilm formation refers to the attachment of microorganisms to surfaces and the subsequent development of multiple layers of cells.

(29) The term antibiofilm refers to inhibition of microbial biofilm formation and disruption or dispersal of preformed biofilms.

(30) The term infection refers to the invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body. An infection may cause no symptoms and be subclinical, or it may cause symptoms and be clinically apparent. An infection may remain localized, or it may spread through the blood or lymphatic vessels to become systemic (body wide). Microorganisms that live naturally in the body are not considered infections.

(31) The term wound refers to a type of injury in which skin is torn, cut, or punctured (an open wound), or where blunt force trauma causes a contusion (a closed wound). In pathology, it specifically refers to a sharp injury, damages to the dermis of the skin.

(32) The term acute wound refers to those that are new and in the first phase of healing. Acute wounds are characterized by skin layers that have been punctured or broken through by an external force or object. Any acute wound can progress to a chronic wound if it does not heal within the expected time frame or as a result of poor blood supply, oxygen, nutrients or hygiene. Acute wounds should be properly treated to avoid infection, inflammation or constant pressure. Acute wounds are categorized based on causes such as lacerations, abrasions, punctures, incisions, gunshots, burns, and type according to the size and depth (superficial or deep).

(33) The term chronic wound refers to a wound that just will not repair itself over time. Chronic wounds are often thought to be stuck in one of the phases of wound healing, and are most often seen in the older adult population. Typically, if a wound is not healing as expected within 2-3 months, it is considered chronic. Chronic wounds include pressure ulcers (e.g. bed sores), arterial and venous leg ulcers, and diabetic ulcers.

(34) The term disinfectants refers to substances that are applied to non-living objects to destroy microorganisms that are living on the objects. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical and/or chemical process that kills all types of life. Disinfectants are different from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants are also different from biocidesthe latter are intended to destroy all forms of life, not just microorganisms. Disinfectants work by destroying the cell wall/membrane of microbes or interfering with metabolism and growth.

(35) The term inhibition refers to at least a decrease of wound-associated bacterial growth and biofilm formation.

(36) The term mammal for purposes of treatment refers to any animal classified as a mammal, including humans, domestic and farm animals, and zoo, sports or pet animals, such as dogs, horses, cats, cattle, pigs, sheep, etc.

(37) The term prevention refers to at least preventing a condition associated with bacteria occurring in a mammal, particularly when the mammal is found to be predisposed to having the condition but has not yet been diagnosed as having it.

(38) The term subject refers to a living vertebrate such as mammal (preferably human and pet animals) in need of treatment.

(39) The term therapeutically effective amount refers to a quantity of a composition high enough to provide a significant positive modification of the subject's condition(s) to be treated.

(40) A preventative amount as used herein includes a prophylactic amount, for example, an amount effective for preventing or protecting against wounds, skin infections and related diseases, and symptoms thereof, and amounts effective for alleviating or healing wounds, skin infections, related diseases, and symptoms thereof. By administering a peptide suitable for use in methods of the invention concurrently with an antimicrobial, the peptide and/or the antimicrobial may be administered in a dosage amount that is less than the dosage amount required when the antimicrobial is administered as a sole active ingredient. By administering lower dosage amounts of active ingredient, side effects associated therewith could be reduced.

(41) The term treatment refers to an intervention performed with the intention of preventing the further development or altering the pathology of an existing disorder. Accordingly, treatment refers to both therapeutic treatment and prophylactic or preventative measures. Those in need of treatment include those already with the infection as well as those in which the infection is to be prevented. In regards, to wound infections, treating or treatment is intended to mean at least the mitigation of wound healing conditions associated with bacterial infections in a subject, such as a mammal, including but not limited to, a human, that is affected at least in part by the condition, and includes, but is not limited to, modulating, inhibiting the condition, and/or alleviating the condition.

(42) The term metal ion salt refers to salt of a metal ion such as zinc chloride, zinc lactate, zinc citrate, zinc gluconate, zinc sulfate zinc acetate, silver ion or silver sulfadiazine, silver sulfate, silver nitrate, and silver carbonate.

(43) The present invention may teach anti-infective compositions offering antimicrobials and antibiofilm activity, containing combinations of chelating agents with other antimicrobial agents, such as, for example, antimicrobials/antibiofilm compounds, metal ion salts with gelling agents, surfactants or stabilizing agents.

(44) Novel compositions that combine chelating agents together with metal ion salts such that lesser quantities of chelating agents and/or metal ion salts than would normally be necessary for an antimicrobial composition are used to achieve significant bacterial growth and biofilm inhibition. Higher concentrations of these compounds can be used if it is desired for certain applications.

(45) The amount of EDTA to be used in the antimicrobial composition of this invention can be between 10000 to 100000 mg/L. The higher end of this stated range might be used to prepare a concentrated product that would be diluted prior to use. For non-concentrated products, the amount of to be used in this invention is preferably between about 5000 to 10000 mg/L. Preferably, the range is between about 1000 to 5000 mg/L, more preferably 0.1 to 1 mg/ml.

(46) The amount of citrate to be used should be between about 1000 to 5000 mg/L. The higher end of this range might apply if the compositions were formulated as a concentrate. For non-concentrated products, the amount of chelating agent to be used in this invention is preferably between about 500 to 5000 mg/L. Preferably, the range is between about 1000 to 3000 mg/L, more preferably between about 2000 to 3000 mg/L, and more preferably 1 to 10 mg/ml.

(47) Preparation

(48) By one method, if a two-component composition is formed containing one or two chelating agents and a metal ion salt, these compounds can be combined in the following manner. With good stirring, a chelating agent can be dissolved in water, followed by a metal ion salt. It should be noted, however, that the addition order can be reversed.

(49) Additionally, antimicrobials/antimicrobial peptides, antibiotics, antibiofilm compounds, quaternary ammonium compounds and surfactants also may be advantageously combined with chelating agents in an antimicrobial composition. A composition of the invention comprises: (a) a small amount of at least one or two chelating agent; (b) a small amount of a metal ion salt or iron-sequestering glycoprotein or antimicrobial peptide or an antibiotic or an antibiofilm compound; and (c) a sparing amount of at least one compound from the group consisting of a stabilizing agent and/or a gelling agent and/or a surfactant, wherein, the amount of each of component (a), (b) and (c) is sufficient to form, in combination, an effective anti-infective composition for prevention and treatment of acute and chronic wound infections (infections of cuts, bruises, surgical sites, lacerations, abrasions, punctures, incisions, gunshots, burns, pyoderma, atopic dermatitis, eczema, pressure ulcers, venous and artery leg ulcers diabetic foot ulcers, etc).

(50) The concentration of active components in the compositions may vary as desired or necessary to decrease the amount of time the composition of the invention is used to prevent or treat wound infections and for disinfection. These variations in active components concentration are easily determined by persons skilled in the art.

(51) Compositions

(52) The present invention may include unique and enhanced anti-infective compositions for the prevention and treatment of wound infections comprising at least two chelating agents and one metal ion salt.

(53) In an embodiment, two chelating agents and a metal ion salt containing composition includes an antimicrobial compound. The chelating agents and a metal ion salt containing composition with an antimicrobial and/antibiofilm compound has an enhanced inhibitory effect on wound infection-associated bacterial growth and biofilm formation. Furthermore, addition of an antimicrobial compound to a composition containing chelating agents and a metal ion salt can make the composition effective against pathogens associated with wound infections and microbial contamination causing food-borne diseases.

(54) In an embodiment of the invention, an enhanced antimicrobial-antibiofilm composition comprises at least one or two chelating agents, one metal ion salt and one or more antimicrobial agents comprising antiseptics (e.g., triclosan, chlorhexidine salt, cetylpyridinium chloride, etc.), antibiotics and bacteriocins (e.g., nisin, epidermin, gallidennin, cinnamycin, duramycin, lacticin 481, etc.), and iron-sequestering glycoproteins (ovotransferrin, lactoferrin and serrotransferrin). Additionally, the wound care or disinfectant compositions may comprise ingredients such as citrate (e.g., citric acid, zinc citrate, sodium citrate, potassium citrate, etc.), minerals (e.g., mineral salts such as zinc chloride, zinc gluconate, zinc lactate, zinc citrate, zinc sulfate, zinc acetate, silver, silver sulfate, silver sulfadiazine, silver nitrate, silver carbonate, etc.), and triterpenoids (e.g., oleanolic acid and ursolic acid) and chitosan

(55) In an embodiment, a composition comprises an antibiotic and one or two chelating agents and also one metal ion salt. Antibiotics are well known. Groups of antibiotics include, but are not limited to, -lactam inhibitors (e.g., penicillin, ampicillin, amoxicillin, methicillin, etc.), cephalosporins (e.g., cephalothin, cephamycin, etc.), aminoglycosides (e.g., streptomycin, tobramycin, etc.), polyenes (e.g., amphotericin, nystatin, etc.), macrolides (e.g., erythromycin, etc.), tetracyclines (e.g., tetracycline, doxycycline, etc.), nitroimidazole (e.g., metronidazole), quinolones (e.g., nalidixic acid), rifamycins (e.g., rifampin), and sulfonamides (e.g., sulfanilamide), nitroaromatics (e.g., chloramphenicol) and pyridines (e.g., isoniazid).

(56) In an embodiment, a composition comprises an antiseptic, one or two chelating agents and one metal ion salt. Antiseptics are agents that kill or inhibit the growth of microorganisms on the external surfaces of the body. Antiseptics include, but are not limited to, triclosan, chlorhexidine salt, and cetylpyridinium chloride.

(57) In an embodiment, a composition comprises an antibiofilm compound, one or two chelating agents and a metal ion salt. Antibiofilm compounds include, but not limited to, DispersinB, DNase I, Proteinase K, apyrase, cis-2-decnoic acid, alginate lyase, lactoferrin, gallium, cellulase, and 5-fluorouracil.

(58) In an embodiment, a composition is effective for inhibiting growth and biofilm formation in wound infection and food-borne disease associated bacteria. The composition is also effective in disrupting or dispersing preformed biofilms, which makes biofilm-embedded bacteria more susceptible to antimicrobial killing. Under appropriate environmental conditions, such as moisture and pH, infections can be modulated using embodiments of the invention.

(59) An embodiment of the invention may also include other pharmaceutically acceptable vehicles, diluents, and additives such as antioxidants, anti-inflammatory compounds, vitamins, tissue degrading enzymes, buffers and solutes that render the formulation isotonic in the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents, surfactants and thickening agents.

(60) Wound Care Formulations

(61) A composition of the invention may be added to a variety of formulations suitable for applying/delivering the composition to wounds, including, but not limited to, disinfecting solutions, lotions, creams, gels, sprays, gel spray, bandage, dressings, wraps, gauze, tapes, adhesives and wound irrigation devices. To provide such formulations, a composition of this invention is combined with one or more pharmaceutically acceptable excipients.

(62) Formulations including, but not limited to, pharmaceutically acceptable compositions comprising one or two chelating agents and a metal ion salt in combination with an antiseptic, an antibiotic, an antimicrobial, an iron-sequestering glycoprotein, a bacteriocin, extracellular matrix or chitosan can be prepared by any known method.

(63) In general, methods of manufacturing anti-infective compositions may comprise combining a pharmaceutically acceptable carrier and an effective amount of both chelating agents and a metal ion salt with an antiseptic, an antibiotic, a bacteriocin, an antimicrobial peptide or chitosan.

(64) A variety of carriers and excipients can be used to formulate an embodiment of this invention and are well known. Such pharmaceutically acceptable vehicles include, but are not limited to, water, ethanol, humectants such as polypropylene glycol, glycerol and sorbitol, gelling agents such as cellulose derivatives, polyoxypropylene/polyoxyethylene block copolymers, carboxy methyl cellulose, pluronic F-127, sodium alginate, polyethylene glycol, thickening agents such as Carbopol 934.

(65) Method of Treatment

(66) Another aspect of this invention may include a method for treating wound infections, and also for decontaminating wound surfaces as well as food/meat processing facilities. In general, wound infections may be treated by applying to the infected wound of a subject with an effective amount of one or more chelating agents and a metal ion salt in combination with one or more antimicrobial agent effective to reduce wound infections.

(67) Before selling meat such as chicken, beef and pork for consumption, it is necessary to stop or retard the growth of pathogenic microorganisms and it is preferable to kill pathogenic microorganisms such as bacteria which may cause food poisoning due to their presence in the meat. Thus, the invention provides a method of preventing or treating meat spoilage comprising topical use of the composition of the invention on meat or meat products. Meat or meat products may be one or more of beef, pork, lamb, goat, horse, chicken and fish. The meat or meat products may include intestine or intestinal parts of pigs, cattle, sheep, goats and horses used for making sausage casings. They may further include collagen or cellulose used for making artificial sausage casings

(68) The compositions may be applied by one or more of coating, spraying, misting, injecting, soaking, flushing, dipping and rinsing. The flushing may include flushing water lines or meat processing lines and cleaning equipment in meat processing and packaging plants.

(69) For use in treating or disinfecting meat, preferred concentration range of ingredients may include: (i) Sodium Citrate: (a) 50,000 mg/L-100,000 mg/L, (b) 25,000 mg/L-50,000 mg/L, (c) 10,000 mg/L-25,000 mg/L, (d) 5,000 mg/L-10,000 mg/L, & (e) 1,000 mg/L-5,000 mg/L. (ii) Disodium EDTA: (a) 10,000 mg/L-25,000 mg/L, (b) 5,000 mg/L-10,000 mg/L, (c) 1,000 mg/L-5,000 mg/L, (d) 100 mg/L-1,000 mg/L, & (e) 100 mg/L-500 mg/L (iii) Zinc Chloride: (a) 1,000 mg/L-5,000 mg/L, (b) 500 mg/L-1,000 mg/L, (c) 100 mg/L-500 mg/L, and (d) 10 mg/L-100 mg/L.

(70) In one embodiment, one or more chelating agents and a metal ion salt together is formulated as pharmaceutically acceptable medicament as described herein comprising a carrier and an effective amount of composition comprising one or more chelating agents and a metal ion salt as active ingredients.

(71) An exemplary dosing regime of a wound care composition of this invention is application of a composition to the wound surface of a subject (animal or human) at least once or twice. According to this embodiment, a subject would apply a composition of the invention to the wound surface from one to three times daily depending on the type of wound and severity of infection. For animals or pets, the composition of the invention can be used as a lotion or a cream, or a gel or a spray or a dressing twice or thrice a day.

(72) In a further embodiment of the invention, an enhanced wound anti-infective composition does not present any antibiotic resistance concerns and bio-compatibility/safety issues. Also, the composition of this invention comprising one or two chelating agents (EDTA and sodium citrate) and a metal ion salt (zinc chloride or zinc sulfate or zinc lactate) has GRAS (Generally Recognized as Safe) status and all these ingredients are food as well as feed additives.

(73) The present invention may be better understood with reference to the following examples. These examples are intended to be representative of specific embodiments of the invention, and are not intended as limiting the scope of the invention.

EXAMPLES

Example 1: Inhibitory Effect of Sodium Citrate, EDTA and Zinc Chloride Alone and in Combination on Methicillin-Resistant Staphylococcus aureus (MRSA) Growth and Biofilm Formation

(74) An overnight broth culture of S. aureus was grown in TSB and used as inoculum. 96-well microplates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and together (Sodium chloride+EDTA+Zinc chloride) were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A composition, comprising sodium citrate, EDTA and zinc chloride showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 1).

Example 2: Inhibitory Effect of Sodium Citrate, EDTA and Zinc Chloride Alone, and in Combination on Methicillin-Resistant Staphylococcus pseudintermedius (MRSP) Growth and Biofilm Formation

(75) An overnight broth culture of methicillin resistant S. pseudintermedius was grown in TSB and used as inoculum. 96-well microplates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and together (Sodium chloride+EDTA+Zinc chloride) were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A composition, comprising sodium citrate, EDTA and zinc chloride showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 2).

Example 3: Inhibitory Effect of Sodium Citrate, EDTA, and Zinc Chloride Alone, and in Combination on Pseudomonas aeruginosa Growth and Biofilm Formation

(76) An overnight broth culture of P. aeruginosa was grown in TSB and used as inoculum. 96-well microplates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and together (Sodium chloride+EDTA+Zinc chloride) were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A composition, comprising sodium citrate, EDTA and zinc chloride showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 3).

Example 4: Inhibitory Effect of Sodium Citrate, EDTA, and Zinc Chloride Alone and in Combination on Listeria monocytogenes Growth and Biofilm Formation

(77) An overnight broth culture of L. monocytogenes was grown in TSB and used as inoculum. 96-well microplates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and together (Sodium chloride+EDTA+Zinc chloride) were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A composition, comprising sodium citrate, EDTA and zinc chloride showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 4).

Example 5: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Methicillin-Resistant Staphylococcus aureus [MRSA] Growth and Biofilm Formation

(78) An overnight broth culture of S. aureus (MRSA) was grown in TSB and used as inoculum. 96-well microplates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and Sodium citrate+EDTA, Sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA and Sodium citrate+ZnCl.sub.2 combinations showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 5).

Example 6: Effect of Sodium Citrate, EDTA, and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Methicillin Resistant Staphylococcus pseudintermedius (MRSP) Growth and Biofilm Formation

(79) An overnight broth culture of MRSP was grown in TSB and used as inoculum. 96-well microplates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and Sodium citrate+EDTA, Sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA, Sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 6).

Example 7: Inhibitory Effect of Sodium Citrate, EDTA, and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2 and EDTA+ZnCl2 Combinations on Pseudomonas aeruginosa Growth and Biofilm Formation

(80) An overnight broth culture of P. aeruginosa was grown in TSB and used as inoculum. 96-well microplates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and Sodium citrate+EDTA, Sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA, and EDTA+ZnCl.sub.2 combinations showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 7).

Example 8: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Salmonella choleraesuis ATCC 10708

(81) An overnight broth culture of S. choleraesuis ATCC 10708 was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 8).

Example 9: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Escherichia coli O157:H7

(82) An overnight broth culture of E. coli O157:H7 was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA, Sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA or zinc chloride alone (FIG. 9).

Example 10: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and in Combination on Escherichia coli O157:H7

(83) An overnight broth culture of E. coli O157:H7 was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and together (Sodium chloride+EDTA+Zinc chloride) were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A composition comprising sodium citrate, EDTA, and ZnCl.sub.2 showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 10).

Example 11: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Staphylococcus Epidermidis

(84) An overnight broth culture of S. epidermidis was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2 and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 11).

Example 12: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Coagulase-Negative Staphylococci (CoNS-42)

(85) An overnight broth culture of CoNS-42 was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 12).

Example 13: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Streptococcus agalactiae ATCC 12386

(86) An overnight broth culture of S. agalactiae was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 13).

Example 14: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Klebsiella pneumoniae

(87) An overnight broth culture of K. pneumoniae was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 14).

Example 15: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Acinetobacter baumannii

(88) An overnight broth culture of A. baumannii was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 15).

Example 16: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Stenotrophomonas maltophilia

(89) An overnight broth culture of S. maltophilia was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 16).

Example 17: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Vancomycin-Resistant Enterococci (VRE)

(90) An overnight broth culture of VRE was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 17).

Example 18: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Enterococcus Faecalis

(91) An overnight broth culture of E. faecalis was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 18).

Example 19: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Proteus Mirabilis

(92) An overnight broth culture of P. mirabilis was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 19).

Example 20: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Candida albicans

(93) An overnight broth culture of C. albicans was grown in TSB and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA combination showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA alone (FIG. 20).

Example 21: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone, and Sodium Citrate+EDTA, Sodium Citrate+ZnCl2, and EDTA+ZnCl2 Combinations on Malassezia pachydermatis

(94) An overnight broth culture of Malassezia pachydermatis was grown in Sabouraud Dextrose Broth and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and sodium citrate+EDTA, sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A Sodium citrate+EDTA, Sodium citrate+ZnCl.sub.2, and EDTA+ZnCl.sub.2 combinations showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA or zinc chloride alone (FIG. 21).

Example 22: Inhibitory Effect of Sodium Citrate, EDTA and ZnCl2 Alone and in Combination on Malassezia pachydermatis

(95) An overnight broth culture of Malassezia pachydermatis was grown in Sabouraud Dextrose Broth and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA or Zinc chloride) separately and together (Sodium chloride+EDTA+Zinc chloride) were inoculated and incubated at 37 C. for 24 hours. Growth of planktonic cells based on absorbance at 600 nm using Labsystems Multiskan Ascent microplate reader was determined. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. A composition comprising sodium citrate, EDTA, and ZnCl.sub.2 showed an enhanced inhibitory effect on biofilm formation, as compared to sodium citrate, or EDTA, or zinc chloride alone (FIG. 22).

Example 23: Inhibitory Effect of Sodium Citrate and EDTA Alone and in Combination on Malassezia pachydermatis

(96) An overnight broth culture of Malassezia pachydermatis was grown in Sabouraud Dextrose Broth and used as inoculum. 96-well microtiter plates containing TSB in the absence and the presence of each compound (sodium citrate or EDTA) separately and together (Sodium citrate+EDTA) were inoculated and incubated at 32 C. for 48 hours. Biofilm was measured by discarding the media in the wells, rinsing the well three times with water, and staining the bound cells with crystal violet. The dye was then solubilized with 33% acetic acid, and absorbance at 630 nm was determined using a microtiter plate reader. The Experiment was repeated four times and the results combined. A composition comprising sodium citrate and EDTA showed an enhanced inhibitory effect on biofilm formation at p=0.04, as compared to sodium citrate or EDTA alone (FIG. 23). The unit of all concentrations in FIG. 23 is mg/ml.

Example 24: Inhibitory Effect of Sodium Citrate and EDTA Alone and in Combination on Staphylococcus Aureus

(97) A 12-well polystyrene microtiter plate biofilm assay was used to determine the inhibitory effect of disodium ethylenediaminetetraacetic acid (NaEDTA) and sodium citrate (S. cit) alone and in combination on Staphylococcus aureus. Briefly, Staphylococcus aureus biofilms were developed in a 12-well polystyrene microtiter plate. Initially an overnight culture was grown in TSB for 16 hours at 37 C., the OD.sub.600 was taken and the culture was diluted to 10.sup.4 CFU/ml. To each well either 1 ml of water (control) or 1 ml of treatment was added followed by 1 ml of the diluted S. aureus cell culture. The 12 well plate was incubated for 16 hours at 37 C. The planktonic medium was removed. The wells were rinsed once with 10 mM PBS buffer (pH 7.2) and fresh 10 mM PSB buffer (pH 7.2) added to the wells. The plate was sonicated for 15 seconds. The wells were scraped and solution removed from the 12 well plate and put into 10 ml culture tubes. The tubes were vortexed for 30 seconds. 200 l of solution was transferred from the tubes to a 96 well plate where a serial dilution was done. The dilution series was then plated in duplicate onto TSA plates. The plates were incubated for 16 hours at 37 C. Biofilm-embedded viable cells were quantified by colony forming unit (CFU) counts after 16 hours of incubation. The experiment was repeated twice and the results are combined. The combination of NaEDTA and sodium citrate performed better than NaEDTA or sodium citrate alone. In particular, the combination of NaEDTA (0.5 mg/ml) and S. cit (6.4 mg/ml) performed significantly better than NaEDTA at 0.5 mg/ml (p=0.05421333) or sodium citrate at 6.4 mg/ml alone (p=0.01529095), as shown in FIG. 24.

Example 25: Inhibitory Effect of Sodium Citrate and EDTA Alone and in Combination on Malassezia furfur

(98) A 12-well polystyrene microtiter plate biofilm assay was used to determine the inhibitory effect of disodium ethylenediaminetetraactic acid (NaEDTA) and sodium citrate (S. cit) Formulation on Malassezia furfur. Briefly, Malassezia furfur biofilms were developed on 12-well polystyrene microtiter plate to provide a rapid and simple method for assaying biofilm embedded Malassezia furfur. The mDixon agar plate was heavily inoculated with glycerol stock of Malassezia furfur and incubated at 32 C. for 4 days. The colonies were then inoculated in 20 mls of mDixon media and incubated at 32 C. for 2 days. The cells were pelleted by centrifuging at 8000 rpm for 10 minutes. The supernatant was removed and cells were resuspended in 20 mls of mDixon media. The cells were diluted to approximately 110.sup.4 cfu/ml. Add to each well of a 12-well microtiter plate 1.0 ml water (control) or 1.0 ml of testing agent then add 1.0 ml of the diluted liquid culture to each well of the 12-well plate. Incubate the plate at 32 C., rocking at 15 rpm for 24 hrs to allow cells to adhere to plate. After 24 hrs, gently remove the media (containing planktonic cells) and gently wash each well 1-2 times with 2.0 ml of sterile PBS. Remove the wash. Gently deposit 1.0 ml of fresh liquid growth media to each well. Gently deposit 1.0 ml water (control) or testing agent to each well. Incubate plate at 32 C., rocking at 15 rpm for another 24 hours. Gently remove the media/planktonic cells and gently wash each well twice with 2:0 ml sterile PBS. Remove the wash. Add 2.0 ml of fresh sterile PBS to each well. Sonicate the 12 well plate for 15 seconds. Remove the biofilm containing PBS solution, scrapping the bottom of the plate with the pipette tip and place in a sterile 15 ml tube. Vortex tubes for 30 seconds. 200 l of solution was transferred from the tubes to a 96 well plate where a serial dilution was done. The dilution series was then plated in duplicate onto mDixon plates. Biofilm-embedded viable cells were quantified by colony forming unit (CFU) counts after 4 days of incubation at 32 C. The experiment was repeated twice and the results are combined. The combination of NaEDTA (0.5 mg/ml) and S. cit (3.2 mg/ml) performed significantly better than NaEDTA at 0.5 mg/ml (p=0.0129) or sodium citrate alone (p=0.00007), as shown in FIG. 25. FIG. 25 also shows that the combination of NaEDTA (0.5 mg/ml) and S. cit (6.4 mg/ml) performed significantly better than NaEDTA at 0.5 mg/ml (p=0.0054) or sodium citrate alone (p=0.00002).