Phenol Coefficient Method Research Articles

Formulation of Silver Nanoparticles Liquid Hand Wash with Polyvinyl Alcohol as Stabilizer

According to Global Burden of Disease reported on 2019, about 1.53 million deaths caused by infectious diseases such as pneumonia and diarrhea. Triclosan is one of the active ingredient commonly used in antibacterial soap as one way to prevent the spread of infectious disease.. However, bacteria resistance against triclosan has been reported. Silver nanoparticles (AgNP) is an alternative antibacterial that potential to be used in liquid hand wash. However AgNp tend to aggregate during storage, thus stabilizer is needed This study aims to synthesize AgNP, formulate the liquid hand wash contain AgNP with polyvinil alcohol as stabilizer, and evaluate its effectiveness against Escherichia coli, Staphylococcus aureus, and Salmonella thypi. AgNP was prepared using the chemical reduction method between silver nitrate and sodium borohydride, followed by its characterization using UV-Vis spectrophotometer, TEM, PSA, and AAS. The physical characteristic of AgNp-liquid hand wash were also evaluated. Further, the antibacterial activity of AgNP-handwash was evaluated by phenol coefficient method. The peak of UV absorption spectrum of colloidal was found at 404.2 nm indicated the presence of AgNP. Ag content in AgNP colloidal was 38.405 mg/Kg ± 0,008. The spherical shape of AgNP was observed. The AgNP size was 65.1 nm with polydispersity index value of 0.543, and zeta potential value was -22.25 mV. The obtained AgNP-hand wash met the Indonesian standard criteria and was stable for 28 days. The best phenol coefficient value was obtained at formulation with addition of 30% AgNP (0.1 for S. typhi, 0.4 for E. coli, and 0.01 for S. aureus).

Uji Aktivitas Antiseptik Ekstrak Etanol Daun Sirih (Piper betle Linn.) dalam Obat Kumur terhadap Staphylococcus aureus secara in Vitro

Betle leaf (Piper betle Linn.) is very popular in Indonesia. Betle leaf is useful for dental health and frequently used as mouthwash; to eliminate body and mouth odor; treats mouth ulcer, nosebleed, itching, ulceration and vaginal discharge in women. An oral cavity is a place for bacteria. If there is a bacterial immunity reduction, that was originally commensal bacteria can turn into a pathogen that cause infection. One of bacteria that commonly found in the oral cavity is Staphylococcus aureus. The bacteria have the ability to occupy and form biofilm on biomaterials that cause resistant to antimicrobials, thus making it difficult to eradicate host that is infected by S. aureus. Previous study reported a multidrug resistant of S. aureus that could cause death, that to overcome it, betle leaves extract ethanol in vitro antiseptic test to S.aureus was conducted. The test was conducted by the phenol coefficient method using S. auereus ATCC 25923 bacteria. Povidone iodine mouthwash that is circulated in the market is used as a comparison. The results showed that mouthwash containing ethanol extract of betle leaf had a phenol coefficient value of 1.87 while povidone iodine mouthwash as a comparison, had a phenol coefficient of 1.0. Mouthwash containing ethanol extract of betle leaf had higher antiseptic effectiveness than the comparative mouthwash.

コアグラーゼ‐エンテロトキシン型別で分類したＭＲＳＡに対する各種消毒剤の殺菌効果

The bactericidal effect of four kinds of disinfectant-benzethonium chloride, benzalkonium chloride, chlorhexidine gluconate and alkyl diaminoethyl glycine-was evaluated against 30 strains of Staphylococcus aureus which comprised of 24 strains of Methcillin-resistant Staphylococcus aureus (MRSA) and six of Methicillin-sensitive Staphylococcus aureus (MSSA). The effect was measured by the phenol coefficient method and the MRSA strains were classified by typecombination of coagulase and enterotoxin as IIA, IIB, IIC and IINT (non-typable)The results were as follows: 1) All strains except for three strains of MRSA and MSSA became growth-inhibited within 15 seconds due to each disinfectant at a rate of 0.1% which was the ordinary dose in clinical use. 2) There were differences in inhibition time by 0.02% of the disinfectants among the MRSA type-combinations.So far as our materials were concerned, we concluded that there was no necessity to distinguish MRSA from MSSA when “disinfection” is considered.

A Study on the Bactericidal Effect of Sodium Chlorite

The bactericidal effects of solutions of sodium chlorite (NaClO2) at various pH values was studied by several methods (the phenol coefficient method, available chlorine germicidal equivalent concentration method and phenol coefficient method under dirty conditions).A 2.73% NaClO2 solution at pH 8.8-9.1 showed no bactericidal effect against E. coli and S. aureus within 15min, but it destroyed them within 2.5min when the pH value was adjusted to 4.0. The bactericidal effect of the solution was increased by elevating the acidity of the solution, and the NaClO2 solution at the lowest concentration adjusted to pH 2.0, had a bactericidal effect. Even at pH 4.0, the effect of the high-concentration solution was sufficient.The bactericidal effect of NaClO2 at pH 4.0 was independent of the use of lactic acid, acetic acid or hydrochloric acid for pH adjustment. However at pH 2.0, the organic acids were superior to the inorganic acid as the pH regulator.

A Study of Bactericidal Effect of Sodium Chlorite Preparation

The bactericidal effect of a sodium chlorite preparation recently developed in the USA was examined with several test methods (available chlorine germicidal equivalent concentration method in A. O. A. C., phenol coefficient method and phenol coefficient method under dirty conditions). The changes with the lapse of time of available chlorine and bactericidal effect were also examined. The base NaClO2 solution exhibited no bactericidal effect, but when lactic acid was added as the activator, it became effective.Base concentration of NaClO2 (%) and available chlorine concentration (ppm) with the activator allowing growth at 5min but not 10min of E. coli, P. aeruginosa, S. aureus and B. subtilis spores were 0.029 (500), 0.014 (250), 0.058 (1000) and 0.23% (4000ppm), respectively. On the other hand, the corresponding values of sodium hypochlorite were 0.015 (150) of E. coli and P. aeruginosa and 0.025% (250ppm) of S. aureus and B. subtilis spores.These results indicated that equivalent bactericidal effects at almost the same concentration of both NaClO2 and NaClO could be expected of P. aeruginosa, but the base concentration of the NaClO2 preparation needed to be several times as high as that of NaClO in order to obtain equivalent bactericidal effects of the other 3 species. Bactericidal effect of E. coli under dirty conditions was one-half of that in clean conditions for NaClO2 and from one-third to one-fifth for NaClO. The degree of decrease suggested less influence of dirty conditions for NaClO2.Available chlorine immediately after preparing the use dilution was decreased to one-half, one-fourth…one-fortieth with the lapse of preservation time. However, the bactericidal effect was enhanced from 1 day after the preparation, continued to increase or remained constant up to 7 days and was lower after 10 days.

Influence of Serum on Antibacterial Activity of Disinfectants and Evaluation of Disinfectant Testing Methods

Influence of serum on antibacterial activity of disinfectants and evaluation of disinfectant testing methods, ie, phenol coefficient method and minimum inhibitory concentration method, were studied. Changes in the effect of various disinfectants such as phenol, saponated cresol solution, povidone-iodine, benzethonium chloride and chlorhexidine were determined against various strains of S. aureus, S. typhi, E. coli, Klebsiella, Serratia, P. aeruginosa, P. maltophilia, P. cepacia and A. xylosoxidans.1) Antibacterial activity of phenol, cresol and povidone-iodine reduced very slightly after serum is added, but that of serum-added benzethonium chloride and chlorhexidine decreased remarkably. 2) The bactericidal effect of serum-added disinfectants 1 hour after contact with bacteria reduced by 25 to 50 % 24 hours after. 3) The antibacterial effect of disinfectants determined by MIC method showed a considerable difference between the effect by phenol coefficient method. So concentration and bactericidal time should be taken into consideration in the evaluation of disinfectant testing methods.

Use of Anatone and Microbiotine in Phenol Coefficient Method for Disinfectant Testing

Abstract Preliminary studies were made of two peptones which are being considered to replace Armour's Peptone or USP Peptic Digest of Animal Tissue. Results indicate that collaborative study on Anatone is warranted.

Resistance of Pseudomonas to Various Chemical Germicides

Abstract Studies were conducted to determine the range of susceptibility of Pseudomonas to seven samples of commercial contact germicides. Tests were made by the official phenol coefficient method, 5.001-5.009. Ranges of resistance for Pseudomonas strains varied with the germicides tested and the concentration of germicide used. Chlorine in water supply systems showed a resistance range of 45-150 ppm to Pseudomonas organisms. Comparative studies were also conducted, using the dilution test method, on various strains of Pseudomonas to determine the effectiveness of disinfectants; strain PRD-10 proved to be the test strain of choice for determining the validity of Pseudomonicidal claims.

Factors Affecting the Activity of Phenolic Disinfectants

Low challenge phenol coefficient and high challenge use-dilution tests were made on a neutral cocoanut oil soap emulsion of o -phenylphenol and aqueous solutions of sodium o -phenylphenate prepared in the laboratory from the phenol using a stoichiometric amount of NaOH as well as with increasing amounts of excess NaOH. The phenol had considerably greater activity in both test methods when emulsified with the neutral soap than when converted to the phenate and dissolved in water. Use dilution test results against Salmonella choleraesuis with both the phenol and the phenate were within the range which would have been predicted from the Salmonella typhosa coefficient results employing the conventional conversion multiple of 20 to determine the maximal number of parts of water to which one part of germicide could be added. With the emulsified phenol this was also true where Staphylococcus aureus was employed in both procedures. With the aqueous solution of the phenate the maximal safe use-dilution by the phenol coefficient found for S. aureus and the same conventional conversion procedure was roughly five times higher than the maximal safe use-dilution found by the use-dilution method. Results with aqueous solutions of the phenate to which increasing amounts of excess NaOH were added showed no significant differences in the phenol coefficient method with either S. typhosa or S. aureus . In the use-dilution method, significant decreases in activity were found as the excess NaOH was increased to 4% with both S. choleraesuis and S. aureus . Although the pH values of aqueous solutions of the phenate were raised as the amount of free NaOH was increased, the decreases in pH observed as the dilution with water was increased were such that only small differences existed at the high critical killing dilutions found in the low challenge phenol coefficient method, whereas rather large differences existed at the lower critical killing dilutions in the high challenge use-dilution method.

Factors Affecting the Activity of Phenolic Disinfectants

Low challenge phenol coefficient and high challenge use-dilution tests were made on a neutral cocoanut oil soap emulsion of o-phenylphenol and aqueous solutions of sodium o-phenylphenate prepared in the laboratory from the phenol using a stoichiometric amount of NaOH as well as with increasing amounts of excess NaOH. The phenol had considerably greater activity in both test methods when emulsified with the neutral soap than when converted to the phenate and dissolved in water. Use dilution test results against Salmonella choleraesuis with both the phenol and the phenate were within the range which would have been predicted from the Salmonella typhosa coefficient results employing the conventional conversion multiple of 20 to determine the maximal number of parts of water to which one part of germicide could be added. With the emulsified phenol this was also true where Staphylococcus aureus was employed in both procedures. With the aqueous solution of the phenate the maximal safe use-dilution by the phenol coefficient found for S. aureus and the same conventional conversion procedure was roughly five times higher than the maximal safe use-dilution found by the use-dilution method. Results with aqueous solutions of the phenate to which increasing amounts of excess NaOH were added showed no significant differences in the phenol coefficient method with either S. typhosa or S. aureus. In the use-dilution method, significant decreases in activity were found as the excess NaOH was increased to 4% with both S. choleraesuis and S. aureus. Although the pH values of aqueous solutions of the phenate were raised as the amount of free NaOH was increased, the decreases in pH observed as the dilution with water was increased were such that only small differences existed at the high critical killing dilutions found in the low challenge phenol coefficient method, whereas rather large differences existed at the lower critical killing dilutions in the high challenge use-dilution method.

An improved tissue toxicity technique for the evaluation of germicidal substances.

The method generally employed for the evaluation of germicides is known as the phenol coefficient test. This test in one form or another is universally employed for the determination of the germicidal potency of compounds or preparations recommended for the destruction of bacteria. The most widely used modification in this country at the present time is the Ruehle and Brewer (1931), U. S. Food and Drug Administration (FDA) phenol coefficient method. The test was originally designed to be used for comparing the bactericidal potency of phenol with phenol-like compounds. However, in recent years the method has been used for the examination of compounds which are totally unlike phenol, with the result that such evaluations have been the cause of considerable confusion and of doubtful value. Another departure has been the freedom which some investigators have taken with the test itself, changing the procedure to favor the compounds under examination. Regardless of the many modifications of the original procedure which have been proposed, it is generally agreed that a phenol coefficient test is of very little or no value for determining the efficiency of a germicide intended for clinical application. A phenol coefficient attempts to compare the toxicity of a germicide for a given organism with that of phenol but gives no information as to its effect on living tissue. For example, a germicide with a high phenol coefficient and a proportionately high toxicity to living tissue would have no advantage over one with a low phenol coefficient and a proportionately low toxicity to living tissue. A new method was proposed in 1935 (Salle and Lazarus), and modified in 1938 (Salle, McOmie, Shechmeister, and Foord), for the evaluation of germicidal substances intended for clinical application (figure 1). The germicides were tested for their effect on living embryonic chick heart tissue fragments as well as for their ability to kill bacteria. Two tests were performed. In one test the bacteria were exposed to a series of dilutions of germicide for 10 min, then transfers were made to nutrient broth to determine the killing dilution. In the other test the tissue fragments were exposed to a series of dilutions of germicide for 10 min, then washed twice with saline, and finally embedded in rabbit plasma to determine the killing dilution. A number known as the Toxicity Index was calculated from the results, which was defined as the ratio of the highest dilution of germicide required to prevent growth of the tissue fragments in 10 min to the highest dilution required to kill the test organism in the same period of time and under similar conditions. Theoretically, an index greater than one means that the germicide is more toxic to the tissue fragments than to the bacteria. As the number increases in size, the germicide decreases in value. Conversely, an index smaller than one means that the germicide is more toxic to the test organism than to the embryonic tissue fragments. As the fraction decreases in magnitude, the germicide increases in value. The smaller the toxicity index the more nearly perfect the chemotherapeutic agent. A phenol coefficient is not determined, and no reference is made to it. There is no relation whatsoever between a phenol coefficient and a toxicity index. In the present investigation the tissue toxicity and the bactericidal tests have been combined in one operation making the procedure simulate actual conditions of germicide therapy as closely as possible.

An Improved Tissue Toxicity Technique for the Evaluation of Germicidal Substances

The method generally employed for the evaluation of germicides is known as the phenol coefficient test. This test in one form or another is universally employed for the determination of the germicidal potency of compounds or preparations recommended for the destruction of bacteria. The most widely used modification in this country at the present time is the Ruehle and Brewer (1931), U. S. Food and Drug Administration (FDA) phenol coefficient method. The test was originally designed to be used for comparing the bactericidal potency of phenol with phenol-like compounds. However, in recent years the method has been used for the examination of compounds which are totally unlike phenol, with the result that such evaluations have been the cause of considerable confusion and of doubtful value. Another departure has been the freedom which some investigators have taken with the test itself, changing the procedure to favor the compounds under examination. Regardless of the many modifications of the original procedure which have been proposed, it is generally agreed that a phenol coefficient test is of very little or no value for determining the efficiency of a germicide intended for clinical application. A phenol coefficient attempts to compare the toxicity of a germicide for a given organism with that of phenol but gives no information as to its effect on living tissue. For example, a germicide with a high phenol coefficient and a proportionately high toxicity to living tissue would have no advantage over one with a low phenol coefficient and a proportionately low toxicity to living tissue. A new method was proposed in 1935 (Salle and Lazarus), and modified in 1938 (Salle, McOmie, Shechmeister, and Foord), for the evaluation of germicidal substances intended for clinical application (figure 1). The germicides were tested for their effect on living embryonic chick heart tissue fragments as well as for their ability to kill bacteria. Two tests were performed. In one test the bacteria were exposed to a series of dilutions of germicide for 10 min, then transfers were made to nutrient broth to determine the killing dilution. In the other test the tissue fragments were exposed to a series of dilutions of germicide for 10 min, then washed twice with saline, and finally embedded in rabbit plasma to determine the killing dilution. A number known as the Toxicity Index was calculated from the results, which was defined as the ratio of the highest dilution of germicide required to prevent growth of the tissue fragments in 10 min to the highest dilution required to kill the test organism in the same period of time and under similar conditions. Theoretically, an index greater than one means that the germicide is more toxic to the tissue fragments than to the bacteria. As the number increases in size, the germicide decreases in value. Conversely, an index smaller than one means that the germicide is more toxic to the test organism than to the embryonic tissue fragments. As the fraction decreases in magnitude, the germicide increases in value. The smaller the toxicity index the more nearly perfect the chemotherapeutic agent. A phenol coefficient is not determined, and no reference is made to it. There is no relation whatsoever between a phenol coefficient and a toxicity index. In the present investigation the tissue toxicity and the bactericidal tests have been combined in one operation making the procedure simulate actual conditions of germicide therapy as closely as possible.

Variations in Resistance in E. Typhosa and S. Aureus When Maintained as Specified According to the Official A.O.A.C. Phenol-Coefficient Method

Journal Article Variations in Resistance in E. Typhosa and S. Aureus When Maintained as Specified According to the Official A.O.A.C. Phenol-Coefficient Method Get access L F Ortenzio, L F Ortenzio Insecticide Division, Livestock Branch, Production and Marketing Administration, U. S. Department of Agriculture Search for other works by this author on: Oxford Academic Google Scholar J L Friedl, J L Friedl Insecticide Division, Livestock Branch, Production and Marketing Administration, U. S. Department of Agriculture Search for other works by this author on: Oxford Academic Google Scholar L S Stuart L S Stuart Insecticide Division, Livestock Branch, Production and Marketing Administration, U. S. Department of Agriculture Search for other works by this author on: Oxford Academic Google Scholar Journal of Association of Official Agricultural Chemists, Volume 32, Issue 2, 1 May 1949, Pages 408–417, https://doi.org/10.1093/jaoac/32.2.408 Published: 10 February 2020

Subtilin-Antibiotic Produced by Bacilius subtilis. II. Toxicity of Subtilin to Living Embryonic Tissue.

SummarySubtilin, an antibiotic extracted from Bacillus subtilis, was found to be antagonistic chiefly against Gram-positive organisms, including Mycobacterium tuberculosis and other acid-fast bacteria. Two notable exceptions were Neisseria catarrhalls and N. gonorrhoeae, both Gram-negative but also antagonized by subtilin. The antibiotic showed an extremely low toxicity for embryonic chick heart tissue fragments cultivated in vitro. Under the conditions of the test subtilin was approximately 20 times more toxic to Staphylococcus aureus than to chick heart tissue, a remarkably low tissue toxicity. A unit of subtilin is defined as the amount contained in 1 cc of the highest dilution capable of killing Staphylococcus aureus in 10 minutes at 37°C (F.D.A. phenol coefficient method).

The Phenol Coefficient Method of Testing Disinfectants

The Phenol Coefficient Method of Testing Disinfectants