MXPA99008595A - Method for disinfecting surfaces - Google Patents

Abstract

A surface is disinfected with a solution comprised of a fully or partially neutralized orthophosphate and optionally one or more surfactants. The method provides a safe and effective means of sanitizing surfaces such as cutting boards by removing, reducing or retarding the growth of pathogenic microorganisms without the use of substances that are toxic to humans.

Description

METHOD FOR DISINFECTING SURFACES CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of the co-pending provisional application filed in advance serial number 60 / 041,661, filed on March 24, 1997, the entire contents of which are incorporated by reference. DECLARATION ON RESEARCH OR DEVELOPMENT SPONSORED BY THE FEDERAL GOVERNMENT: Not applicable BACKGROUND OF THE INVENTION Infections acquired from contaminated food and food products are becoming more frequent. For example, a 1987 study of a group of patients with diarrhea in the Puget Sound area showed an unexpectedly high incidence of E. Coli 0157: H7 (MacDonald KL, et al, JAMA 259: 3567-3570, 1987). Eighty-nine percent of patients with E. Coli did not have a history of eating undercooked meat. In 1993, an epidemic of E. coli 0157: H7 was traced to undercooked hamburger meat in Washington state. Four children died and several suffered permanent kidney damage. Much of this contamination has been related to the food preparation process, even though two of the E. Coli cases in Washington did not come directly from the consumption of contaminated burgers and are considered to have been acquired through indirect contact. Other bacteria that cause gastroenteritis and diarrhea include spices of Ca pylobacter, Salmonella and Shigella. The presence of Salmonella typhimurium in watermelon, milk powder, and infant formulas has been reported and this has caused severe cases of diarrhea. Salmonella enteritides presents a remarkable increase in its incidence due to the contamination of eggs and products made with eggs. With the apparent proliferation of diseases caused by the ingestion of pathogenic organisms, a greater potential for cross-contamination of foods is observed, such as, for example, cutting boards and other work surfaces used to process and / or prepare birds. , beef, or pork. Several recent studies have shown that bacterial contamination of cutting boards that come into direct or indirect contact with food is mainly due to bacterial biofilms and not to planktonic bacteria. Planktonic bacteria are simple organisms that move in a fluid while a bacterial biofilm consists of colonies of bacteria surrounded by a mucosal glycopolysaccharide envelope, which adheres to surfaces. Most classical microbiology studies starting with Louis Pasteur have been carried out on bacteria growing in an enriched liquid culture medium or in an enriched culture medium solidified in Petri dishes. These enriched culture conditions encourage bacterial growth in planktonic form. In nature, bacteria exist in a more hostile environment and form biofilms. An example of a biofilm is the Legionella bacteria in the air conditioning cooling towers responsible for Legionnaires' disease. Bacteria on wood cutting boards quickly form biofilms that are not recovered by routine cultivation methods and are difficult to remove from contaminated areas. While it is generally accepted that cutting boards can be cleaned using conventional methods, for example hot water and detergents and / or disinfectants, for example quaternary ammonium compounds, an example published in January 1994 showed that live bacteria were observed in adhered biofilms on plastic and wood cutting boards and said article suggested that these bacteria were a potential source of food contamination at home and commercial level. This article concluded that there is a need to develop better ways to remove bacterial biofilms from cutting surfaces (Abrishami, Tall et al. "Bacterial Adherence and Viability on Cutting Board Surfaces," J. Food Safety 14: 153-172, 1994).

COMPENDIUM OF THE INVENTION One aspect of the present invention relates to a method for the treatment of a surface such as, for example, cutting boards and the like which are in direct or indirect contact with food for the purpose of removing, reducing or delay the growth of pathogenic microorganisms such as, for example, E. Coli, Salmonella, campylobacter, shigella and listeria. The method according to the present invention comprises contacting a surface with an effective amount of a contact solution comprising a total or partially neutralized orthophosphate or a combination thereof. Another aspect of the present invention pertains to a method for the treatment of a surface such as, for example, cutting boards and the like which come into direct or indirect contact with food in order to remove, reduce or retard the growth of pathogenic microorganisms. as, for example, E. coli, salmonella, ca pylobacter, shigella and listeria. The method according to the present invention comprises contacting a surface with an effective amount of a contact solution comprising a partially or fully neutralized orthophosphate or a combination thereof and one or more surfactants. The present invention offers a safe and effective method for cleaning surfaces such as, for example, cutting boards by removing, reducing or retarding the growth of pathogenic microorganisms without the use of substances toxic to humans. DESCRIPTION OF THE PREFERRED MODALITIES The term "disinfectant" as used herein indicates the removal, reduction or retardation of the growth of pathogenic microorganisms such as, for example, pathogenic bacteria and yeasts. A trialcalcium metal phosphate is an orthophosphate salt of the formula M3PO4 wherein M is an alkali metal or hydrogen according to that described in U.S. Patent No. 5,354,568, the content of which is incorporated herein by reference. The orthophosphate useful in the method according to the present invention is any of a mixture of partially or fully neutralized phosphate salts such as, for example, disodium monohydrogen phosphate, monosodium dihydrogenphosphate and trisodium phosphate, and the hydrates thereof, such as, for example, dodecahydrate as described in U.S. Patent No. 5,354,568. The most preferred orthophosphate salts are NaßP? and trisodium phosphate dodecahydrate (Na3P04-12 H20). The amount of orthophosphate in the contact solution is an effective amount which can be any amount effective to remove, reduce or retard the growth of pathogenic microorganisms on a surface. The amount of orthophosphate in the contact solution can be any amount necessary to make the solution or treatment effective to remove, reduce or retard the growth of pathogenic microorganisms on a surface and will typically vary from about 1% up to the solubility limit or well saturation of the orthophosphate in the solution. The pH of the treatment solutions may vary from about 7 to about 14, while the preferred range is from about 9 to about 11. Another embodiment of the method according to the present invention comprises the use of a contact solution comprising a surfactant and an orthophosphate as described above. The surfactant may be a nonionic, anionic, cationic, or amphoteric surfactant or a combination of such surfactants. Examples of nonionic surfactants that may be employed in the compositions and methods according to the present invention include, but are not limited to, alkylene oxide condensates of alkylphenols, alkylene oxide condensates of aliphatic alcohols, alkylene oxide condensates of amines. aliphatics, amine oxides, alkanolamides, and the like. Examples of anionic surfactants that can be employed in the compositions and methods according to the present invention include, not limited thereto, anionic surfactants, such as for example carboxylates, sulfonates, sulfates, phosphates, and alkylbenzene sulfonates. Examples of cationic surfactants that may be employed in the compositions and methods according to the present invention include, but are not limited to, quaternary ammonium compounds, such as quaternized amines and the like. Amphoteric surfactants which may be employed in the compositions and methods according to the present invention include, without being limited thereto, betaines, imidazolinium compounds, amino acids and the like. A preferred type surfactant is a non-toxic surfactant or one that exhibits low toxicity and is biodegradable. An alkyl polyglycoside is a particularly preferred surfactant because it is non-toxic, is totally biodegradable and is made from regenerable raw materials. The alkyl polyglycosides that can be employed in the invention have the formula I R 0 O (R 20) b (Z) a I where Ri is a monovalent organic radical having from about 6 to about 30 carbon atoms; R2 is a divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6. Preferred alkyl polyglycosides that can be employed in the compositions and processes according to the invention have the formula I wherein Z is a glucose residue and b is 0 such alkyl polyglycosides are commercially available, example surfactants APG®, GLUCOPON®, PLANTAREN®, or AGRIMUL® from Henkel Corporation, Ambler, PA 19002. Examples of such surfactants include, but are not limited to: 1. GLUPOCON® 220 surfactant - an alkyl polyglycoside wherein the alkyl group it contains 8 to 10 carbon atoms and has an average degree of polymerization of 1.5. 2. Surfactant GLUPOCON® 225 - an alkyl polyglycoside wherein the alkyl group contains from 8 to 10 carbon atoms and which has an average degree of polymerization of 1.7. 3. Surfactant GLUPOCON® 600 - an alkyl polyglycoside wherein the alkyl group contains from 12 to 16 carbon atoms and which has an average degree of polymerization of 1.4. 4. Surfactant GLUPOCON ® 625 - an alkyl polyglycoside in which the alkyl group contains 12 to 16 carbon atoms and having an average degree of polymerization of 1.4. 5. Surfactant APG ® 325 - an alkyl polyglycoside wherein the alkyl group contains from 9 to 11 carbon atoms and which has an average degree of polymerization of 1.6. 6. Surfactant Plantaren ® 2000 - an alkyl polyglycoside in which the alkyl group contains 8 to 16 carbon atoms and having an average degree of polymerization of 1.4. 7. Surfactant Plantaren ® 1300 - an alkyl polyglycoside in which the alkyl group contains 12 to 16 carbon atoms and having an average degree of polymerization of 1.6. 8. Surfactant GRIJMUL® PG 2067 - an alkyl polyglycoside in which the alkyl group contains 8 to 10 carbon atoms and having an average degree of polymerization of 1.7. Other examples include alkyl polyglycoside surfactant compositions consisting of mixtures of compounds of formula I as described in U.S. Patent Nos. 5,266,690 and 5,449,763, the entire contents of which are incorporated herein by reference. The amount of surfactant in the treatment solutions of the present embodiment of the process according to the present invention can be any amount necessary to render the treatment solution effective to remove, reduce or retard the growth of pathogenic microorganisms on a surface and will typically vary from about 1% to about 75% by weight of the total treatment solution and preferably from about 7.0% to about 15% by weight. While the process according to the present invention can be used to disinfect any surface, a hard surface such as wood or plastic is preferred. The process according to the present invention can be applied especially to disinfect cutting boards where foods such as chicken, beef and fish are cut or otherwise handled before cooking or other operation such as, for example, freezing example. In carrying out the process according to the present invention, a surface such as, for example, a wood or plastic surface is contacted with the aqueous solution containing one or more metaltrialkaline phosphates or a solution comprising one or more phosphates. of trialcalino metal and one or more surfactants as described herein. The cleaning and disinfection of a surface can be achieved by any conventional method used to clean surfaces such as by means of a brush or a cloth moistened with the treatment solution or by immersing the surface in the treatment solution or contacting the surface inside a conventional automatic dishwasher for a period of time sufficient to remove, retard or reduce bacterial contamination and / or growth beyond what can be obtained if pure water is used. A surface is treated with a treatment solution containing from about 4% to saturation, preferably about 6% to and more preferably about 8% to saturation of another trialcaline metal phosphate by weight of the solution. A treatment solution comprising a surfactant and a trialkaline metal orthophosphate can contain from about 4% to saturation, preferably about 6% and more preferably about 8% to saturation of trialkaline metal orthophosphate and about 1% to approximately 70% of a surfactant. More preferably, a treatment solution will typically contain from about 5% to about 8% by weight and from about 7% to about 15% by weight of an alkyl polyglycoside. The pH of the treatment solutions may vary from about 7 to about 14, with a range from about 9 to about 11 being preferred. The treatment solutions according to the present invention may also contain other components such as foam removers and disinfectants such as quaternary ammonium compounds. The following examples are presented to illustrate the invention but not to limit it. Example 1 Approximately 50 ul of drop dilution MIC of each treatment solution presented in the following list was deposited in blood dish cultures of the following bacteria: E. coli - E. Coli 01.57: HE Pseu a - Pseudomonas aeruginosa Sale typh - Salmonella typhi Shig - Shigella dysenterica Staph a - Staphylococcus aureus Strep p - Streptococcus pyogenes In addition to the component presented below, each treatment solution contained the following (% by weight): 10% PLANTAREN® 20001; 7% PLANTAREN ® 12002; 4% TRITON® N 1013; 2% VELVETEX ® BK-354; Cocamide diethanolamide 2%. 1) = 5% trisodium phosphate 2) = 1% trisodium phosphate 3) = 1% dimethyl alkyl benzalkonium chloride 4) = 0.5% dimethyl alkyl benzalkonium chloride 5) = 1% trisodium phosphate + 1% of the mono-n-butyl ester of 1, 2-dipropylene glycol Surfactant 1-PLANTAREN® 2000 - a 50% active alkyl polyglycoside wherein the alkyl group contains 8 to 16 carbon atoms and which has an average polymerization degree of 1.4, a product trademark of Henkel Corporation, Gulph Mills, PA. 2-PLANTAREN ® 1200 - a 50% active polyglycoside alkyl wherein the alkyl group contains from 12 to 16 carbon atoms and having an average polymerization degree of 1.4, a branded product from Henkel Corporation, Gulph Mills, PA. 3-TRITON® N 101, a 100% active ethoxylated nonylphenol, a trademark product of Union Carbide Corp. 4-VELVETEX® BK-35, a 35% active cocoamidopropyl betaine, a trademark product of Henkel Corporation, Gulph Mills, PA. The results appear in the table below: Table 1 Organism 1) 2) 3) 4) 5) Sal typh 10 ° 10 ° - 10 ° E. coli 10 ° - - Pseu at 10 ° - - Shig 10 ° - - Staph to 10"1 10 ° 10" 1 10"10 ° Strep p 10" 4 10"1 10" 2 10"10 -2 Zone of inhibition - expressed for greater dilution 10 ° - 10 ~ 8 = dilutions tested - = no zone, no inhibition Example 2 A sufficient number of samples of cutting boards of wood and plastic were inoculated each with a suspension of E. Coli 0157: H7 ATCC No.35150 in 50% horse serum and 10% vegetable oil. Similarly, samples of additional cutting boards were inoculated with a suspension of S. Typhimurium ATCC No.14028 in 50% horse serum and 10% vegetable oil. Samples of cutting boards were allowed to dry for one hour and then heated with one of the 3 treatment solutions below, or with sterile PBS (phosphate buffered solution) as control. Approximately 1 hour or 18-22 hours after the treatment, the recoverable microbial population was determined in each of the cutting table surfaces. In addition to the component presented below, each treatment solution contained the following (% by weight): PLANTAREN ® 20001 at 10%; PLANTAREN ® 12002 at 7%; TRITON ® N 1013 at 4%, VELVETEX ® BK-354 at 2%; Cocamide diethanolamide 2%. 1) = 5% trisodium phosphate or 7.5% (see below) 2) = FORTECH ® + 2500 ppm cleaner or 200 ppm hypochlorite bleach (see below). 3) = 5000 ppm of dimethyl alkyl benzalkonium chloride 4) = 0.05 M PBS aq. 1- Surfactant PLANTAREN ® 2000 - a 50% active alkyl polyglycoside wherein the alkyl group contains from 8 to 16 carbon atoms and having an average degree of polymerization of 1.4, a commercially branded product from Henkel Corporation, Gulph Mills, PA. 2- Surfactant PLANTAREN ® 1200 - a 50% active alkyl polyglycoside wherein the alkyl group contains from 12 to 16 carbon atoms and having an average polymerization degree of 1.4, a commercially branded product from Henkel Corporation, Gulph Mills, PA. 3- TRITON ® N 101, a 100% active nonylphenol ethoxylate, a trademark product of Union Carbide Corp. 4- VELVETEX® BK-35, a 35% active cocoamidopropyl betaine, a commercially branded product from Henkel Corporation, Gulph Mills, PA. 5- FORTECH ® Cleaner, a trademark product of Formula, Corp, Seattle, WA. E. Coli and S. Typhimurium cultures were used to inoculate separate dishes of Tryptic Soy Agar (TEA). The dishes were incubated at a temperature between 30 and 35 ° C for approximately 24 hours to develop a confluent growth. The growth of each of the cultures was suspended separately in a solution comprising 50% horse serum (Northbay Bioscience, catalog number 550-100, 2x100 mL), 10% vegetable oil (Crisco Oil) and 40% PBS. The suspensions were used the same day of the preparation. The population of each of the prepared microbial suspensions was determined immediately before the inoculation of the cutting table samples. Aliquots of each microbial suspension were serially diluted in sterile PBS, and placed in a plate in triplicate using the diptych plating method and tryptic soy agar. The dishes were allowed to solidify, invert and incubate at a temperature between 30 and 35 ° C for 48 to 72 hours. After incubation, colonies per dish were enumerated, and the average number of colony forming units (CFU) per ml of suspension was determined for each of the two inoculations. A total of 16 samples of cutting boards subjected to autoclave treatment (8 wood and 8 plastic) were inoculated with 1.0 ml of each of the E. coli test suspensions. Sixteen samples of cutting boards subjected to additional autoclave treatment (8 wood and 8 plastic; 5 x 5 cm each) were inoculated with 1.0 ml of the test suspension of S. Typhimurium. Samples of inoculated cutting boards were allowed to dry in a bioflower hood for approximately 1 hour (Time = -1 hour). Two samples of wood cutting boards and two samples of plastic cutting boards inoculated with an E. coli suspension were washed with a sterile gauze saturated with a cutting board cleaner for 10 seconds. A similar procedure was performed for samples of cutting boards inoculated with the suspension of S. Typhimurium. The Fortech cleanser was followed by a wash for 10 seconds with a sterile gas sponge saturated in diluted bleach. Each of the samples was rinsed with sterile water. (Time = 0 hours). The washed surfaces were allowed to dry for about 1 hour. The microbial population of one of the samples of wood cutting boards and one of the samples of plastic cutting boards previously inoculated with E. coli was determined approximately 1 hour after washing (time = lh).

Each slice table sample was placed in a separate sterile sample cup containing a minimum of 50 ml of sterile PBS. The surfaces were scraped with a sterile scalpel, and the surface and the scrapes were sonicated in a bath sonicator for approximately 1 minute. The sterile PBS container with the cutting table sample was mixed by vortex mixing for approximately 60 seconds. Serial dilutions were prepared for each test surface in sterile PBS and placed in a plate in triplicate using the plate casting method and TEA. The plates were incubated at a temperature of 30-35 ° C for 48-72 hours. Steps 1 and 2 were repeated for the remaining samples inoculated with E. coli at approximately 18-22 hours after washing (Time = 19 hours). The samples remained in the bioflower bell during the intermediate period. The procedure in sections 2 and 3 was repeated for samples of previously washed cutting boards inoculated with the suspension of S. Tityphimurium. After incubation, the emptying plates were examined to determine bacterial growth and the average number of Colony Forming Units (CFU) recovered from each sample cutting table was determined and recorded. A second experiment was carried out using samples of wood cutting boards inoculated with E. Coli, using a treatment solution (1) with 7.5% TSP and a treatment solution (2) with 200 ppm hypochlorite. The following diagram describes the test performed: Escherichia coli ATCC No.35150 Cleaner Type of Inoculated wash 10 Micro-test Table with E. Coli sec, m-bianus Cut wait 1 hr. juague H20 1 hr 18 hrs.

Control wood + + + PBS wood + + + Plastic + + + Plastic + + + (1) with wood + + + 5% TSP wood + + + plastic + + + plastic + + + (2) with wood + + + 200 ppm wood + + + blanqueaclor plastic + + + plastic + + + (3) wood + + + wood + + + plastic + + + plastic + + + Salmonella Typhimurium ATCC No. 14028 Cleaner Type of Inoculated wash 10 Test micro- Table with S. tphi sec, m embryo cut, wait 1 hr. juague - H20 1 hr 18 hrs Control wood + + + PBS wood + + + Plastic + + + Plastic + + + (1) with wood + + + 5% TSP wood + + + plastic + + + plastic + + + (2) with wood + + + 200 ppm wood + + + + plastic + + + plastic + + + (3) wood + + + wood + + + plastic + + + plastic + + + E. coli ATCC No.35150 Second experiment: Cleaner Type of inoculated wash 10 Micro-test Table with E. Coli sec, m-bian waiting cut 1 hr. juague - H20 1 hr 18 hrs.

Control wood + + + (1) according to wood + + + the above (2) according to wood + + + the above (3) wood + + The following table summarizes the results of the experiments with a 10 second wash with the 3 formulas of cutting boards described above followed by a rinse with sterile water in samples of cutting boards of 5 x 5 cm of wood and 5 x 5 cm of inosulated plastic are Essherishia coli 0157: H7 ATCC No.350150 and Salmonella typhimurium ATCC No. 14028. E. coli% Reduction% Reduction Inoc Wood Plastic 8.12xl08 ((l1)) ccoonn TTPPSS aall 55 %% 95.2 99.97 (3) 95.4 99.91 (2) with 2500 bl1 85.0 99.97 2.54xl0b (1) with 7.5% TSP 93.0 ND (3) 56.0 ND (2) with 200 bl 2.40 ND S. reduction typhimurium reduction% Inoc wood plastic 2 . 54xl09 (1) with 5% TSP 94. 3 99 97 (3) 94. 6 99. 96 (2) with 2500 bl 23.6 99.99 1 - . 1 - ppm bleach 15 20 25

Claims (1)

1. CLAIMS A method for treating a surface, comprising contacting a surface with an effective amount of a contact solution comprising a total or partially neutralized orthophosphate or a combination thereof. The method of claim 1, wherein the fully neutralized orthophosphate is trisodium phosphate. The method of claim 1, wherein the amount of total or partially neutralized orthophosphate is about 1% by weight to about the solubility limit of said orthophosphate in said solution. A method for treating a surface comprising contacting a surface with an effective amount of a contact solution comprising a total or partially neutralized orthophosphate or a combination thereof and one or more surfactants. The method of claim 4, wherein said surfactant is a non-ionic surfactant. The method of claim 5, wherein said nonionic surfactant is an alkyl polyglycoside of the formula I R? O (R20) b (Z) to I wherein Ri is a monovalent organic radical having from about 6 to about 30 carbon atoms; R2 is a divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6. A method for treating a surface comprising contacting a surface with an effective amount of a contact solution comprising a trisodium orthophosphate and an alkyl polyglycoside of the formula IR? O (R20) b (Z) to I wherein Ri is a monovalent organic radical having from about 6 to about 30 carbon atoms; R2 is a divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number having a value from 1 to about 6. A method for treating a surface comprising contacting a surface with an effective amount of a contact solution comprising from about 4% to about 8% by weight of trisodium orthophosphate and from about 7.0% to about 15% by weight of an alkyl polyglycoside of the formula IR! (R20) b (Z) to I where Ri is a monovalent organic radical having from about 6 to about 30 atoms of carbon; R2 is a divalent alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; a is a number that has a value from 1 to approximately 6.