Antiseptics and Disinfectants 2023.pdf

Antiseptics and Disinfectants JANA VANAGA 2023  Biosecurity Detergents, antiseptics and disinfectants play a crucial role in preventing the spread of infectious diseases in veterinary medicine. From pre-operative area washing to disinfection after an outbreak. Veterinaria...

Antiseptics and Disinfectants JANA VANAGA 2023  Biosecurity Detergents, antiseptics and disinfectants play a crucial role in preventing the spread of infectious diseases in veterinary medicine. From pre-operative area washing to disinfection after an outbreak. Veterinarians rely on these products to ensure safe and effective germicidal action.  ANTIMICROBIALS Antimicrobials Antibacterial Antifungal Antivirals Antiprotozoal Antiparasitic Antiseptics Disinfectants Sterilization  The effectiveness of hand washing was proved by Ignaz Semmelweis, a Hungarian obstetrician, as early as the 1840s. Ignaz Philipp Semmelweis was a Hungarian physician and scientist, now known as an early pioneer of antiseptic procedures. Semmelweis discovered that the incidence of childbed fever (women had it after given birth) could be drastically cut by the use of hand disinfection in obstetrical clinics. Childbed fever was common in mid-19th-century hospitals and often fatal. Semmelweis proposed the practice of washing hands with chlorinated lime solutions. Despite various publications of results where hand washing reduced mortality to below 1%, some doctors were offended at the suggestion that they should wash their hands and mocked him for it. He died 14 days later after being beaten by the guards, from a gangrenous wound on his right hand which might have been caused by the beating. Semmelweis's practice earned widespread acceptance only years after his death, when Louis Pasteur confirmed the germ theory, and Joseph Lister, acting on the French microbiologist's research, practised and operated using hygienic methods, with great success.  Detergents, antiseptics and disinfectants are distinguished by their intended use and characteristics and not by their chemical content. Cleaners helps to physically remove foreign materials and is not always a germicide. Any organic material significantly reduces the quality of disinfection. Therefore, surgical instruments should be washed thoroughly, especially with a porous surface or 'teeth'. An antiseptic is a biocide used on living tissues A disinfectant is a biocide used for inanimate objects. Some antiseptics may remain inactive on non-living surfaces and because some disinfectants are dangerous to living tissues, these two should not be replaced by each other. The same product should not be used for both asepsis and disinfection. Even products with an identical active chemical moiety can be formulated to prevent their interchangeable use By changing the concentration and duration of exposure  Disinfec8on An8sep8cs Disinfectants - products that acted on Antiseptics - products that act on microorganisms in the environment. microorganisms present on the animal.  Definition Antiseptics Disinfectants Antiseptics - products that act on Disinfectants - strong chemicals used to microorganisms that are: kill microorganisms in: on the skin, in the external environment: indoors, mucous membranes, clothing, burns maintenance tools, wound surfaces. surgical instruments, in the patient's discharge sputum, Also used to disinfect surrounding healthy feces, tissues as well as body cavities. urine. The effect of these products is fast and it is used in bacteriocidal concentrations. Main objec8ves of disinfec8on in veterinary medicine Main objectives of disinfection in veterinary medicine  DISINFECTION PROTOCOLS Different clinics, farms, procedures in veterinary medicine have different cleaning, antiseptic and disinfection protocols There is no one universal agent that is suitable or effective for all stages of disinfection and asepsis. You can't use one tool for all stages!  MUST BE USED WITH CARE Antiseptics, disinfectants and sterilizers should be used with caution, taking into account their biocidal activity, toxic effects and ability to accumulate in the environment, in the patient and in the caregiver. You! And rising AMR BSAVA PROTECT ME h8ps://www.bsava.com/resources/veterinary-resources/protect-me/  Detergents or Cleansers Cleansers remove dirt and contaminating organisms by solubilization and physical means. Cleansers are often a critical step to proper disinfection or antisepsis as removing gross contamination from an area prior to disinfection or antisepsis. Cleansers can be classified based on the presence and charge of the hydrophilic portion of the molecule. Clipping?  Cleansers: Soap Soaps are anionic surfactants. Dissociation in water liberates a molecule with both a hydrophilic and a hydrophobic portion, which can emulsify and solubilize hydrophobic dirt, fat, and protoplasmic membranes. Once solubilized, this contamination can be rinsed away with water. The ability to solubilize membranes renders soaps antibacterial against gram-positive and acid-fast bacteria. The anionic nature of soaps, however, causes them to be inactivated in the presence of certain positive ions such as free Ca+ in hard water and in the presence of cationic detergents. Inclusion of antiseptic compounds in soap preparations has given them a wider antibacterial spectrum. Chlorhexadine soaps Iodine soaps  Triclosan soap was developed in the 1960s Banned in December 2017. Finding no benefit to consumers and considering the risk of antibiotic resistance.  Cleansers: The quaternary ammonium compounds (QACs) The fourth ammonium compounds (QAC) are examples of cationic surfactants with germicidal activity. These compounds are widely used as disinfectants. Cationic surfactants are readily bound to proteins, fats and phosphates and are therefore of limited value in serum, blood and other tissue residues. In addition, when used in combination with materials such as gauze and cotton balls, they become less germicidal due to the absorption of the active ingredients.  Antiseptics An antiseptic reduces microbes on the skin and other living tissues. Its mechanism of action is non-specific damage to cell Gloves?? membranes or enzymes, care should be taken not to damage the patient's tissues. The ideal antiseptic preparation would have a wide spectrum of activity, low toxicity, high penetration, it would maintain activity in the presence of pus and necrotic tissues, would not cause skin irritation, would not interfere with the normal tissue healing process.  Disinfectants Disinfection is the process of destroying most, if not all, pathogenic organisms from a non-living object, except in the form of spores. Disinfection is sometimes incorrectly mixed with sterilization, a process that completely eliminates all microbial forms by physical or chemical means. Sometimes chemical sterilizers can be considered as disinfectants if shorter exposure periods or concentrations are used. Surface disinfection is the treatment of objects that are too large to be immersed in disinfectants, such as cabinets, tables, chairs, lighting equipment and cages. Immersion disinfection is the immersion of smaller items in disinfectants for a sufficient period of time to destroy most of the contaminating, pathogenic organisms. Ideal properties of the disinfectant include a wide range, rapid action, action in the presence of organic materials (including blood, sputum and feces), compatibility with detergents, low toxicity, low cost, ease of use and extended surface activity. They should not damage tools or metal surfaces, damage rubber, plastic or other materials, and should be odorless.  STERILIZATION Steriliza8on - an acCon or process, physical or chemical, that destroys and disrupts all life forms, especially microorganisms (aEer a certain contact Cme or temperature). Dry heat Steam Chemical vapor Ethylene oxide gas Formaldehyde gas Ultraviolet radiaCon Gamma rays FiltraCon Fire  Disinfectants are divided according to exposure: High-level disinfection destroys all microorganisms except bacterial spores. Intermediate-level disinfection inactivates acid-fast microorganisms, including Mycobacterium tuberculosis, most viruses and fungi, but not necessarily bacterial spores. Low-level disinfection kills most bacteria, some viruses, and some fungi, but not tubercle bacilli or bacterial spores.  Divide based on risk of infection involved in their use: Critical – those that enter or penetrate skin or mucous membranes (e.g., needles, scalpels) should be sterilized Semicritical – those that touch intact mucous membranes (e.g., anesthesia equipment, endoscopes); require high-level disinfection Noncritical – those that do not touch mucous membranes but may contact intact skin (e.g., stethoscopes, cages, tables, food bowls). require low to intermediate-level disinfection  Popular antiseptics and disinfectants Alcohol Halogens Biguanides Aldehydes Oxidizing compounds Phenols  Alcohol Alcohols are one of the most popular anCsepCcs and disinfectants used in veterinary medicine on a daily basis. Ethyl alcohol and isopropyl alcohol are the most commonly used. These compounds are both lipid solvents and protein denaturants. They kill organisms by dissolving the lipid cell membrane and denaturing the cell membrane proteins. Alcohols are most effecCve when diluted with water to 70% ethyl alcohol or 50% isopropyl alcohol. It is believed that at higher concentraAons, the iniAal dehydraAon of cellular proteins makes them resistant to the effect of denaturaAon. Alcohols have excellent an8bacterial ac8vity against most vegeta8ve gram- posi8ve, gram-nega8ve and tuberculosis bacillus organisms, but they do not ac8vate bacterial spores. They are ac8ve against many fungi and viruses, mainly enveloped viruses, due to the dissolu8on of alcohol lipids.  Alcohol Alcohols are not recommended for high-level disinfection or chemical sterilization because they are inactive against bacterial spores and have reduced efficacy in protein-containing secretions, including other biological secretions. Blood proteins are denatured with alcohol and adhere to instruments that are disinfected. After prolonged use, alcohols can damage lens instruments, rubber, some plastic tubes and can be corrosive (corrosive) to metal surfaces. Alcohols are highly flammable, care must be taken in their storage and use before electrocautery or laser surgery.  Alcohol When deciding on ethyl and isopropyl alcohol, it is important to take into account the inactivity of isopropyl against hydrophilic viruses and the potential for misuse of ethyl alcohol (grain alcohol). Both isopropyl and ethyl alcohol are used as effective antiseptics. As their effectiveness is greatly reduced by organic substances such as faeces, mucus and blood, they are most effective on 'clean' skin. They cause a rapid reduction in the number of bacteria, the contact time is 1 to 3 minutes, resulting in the destruction of almost 80% of organisms. Rapid evaporation limits contact time; however, it can be seen that the reduction in the number of bacteria also occurs after the alcohol evaporates from the skin. Alcohol can dry the skin and cause local irritation. In an effort to reduce the drying effect, emollients such as glycerin were added with good results.  Halogens Iodine and Chlorine Both have antimicrobial activity and have been used as antiseptics or disinfectants. Iodine has germicidal activity against gram-positive and gram- negative bacteria, bacterial spores, fungi and most viruses. It kills microorganisms by diffusing into the cell and interfering with metabolic reactions, as well as disrupting the structure and synthesis of proteins and nucleic acids. Iodine has a characteristic odor and is corrosive to metals. It is insoluble in water and is thus prepared in alcohol (tincture).  Halogens Iodine Iodine 'ncture, which was used as early as 1839 in the French Civil War, is most effec(vely formed as a 1-2% iodine solu(on in 70% ethyl alcohol. In this form, most bacteria (approximately 90%) are killed within 3 minutes of administra'on. The an'bacterial ac'vity of this combina'on is greater than that of alcohol alone. Iodine (ncture is irrita(ng and allergic, corrodes metals and stains skin and clothing. Iodine is also painful when used on open wounds and is irrita'ng to the pa'ent's 'ssues; this can delay healing and increase the chance of infec'on. For these reasons, this prepara(on is no longer popular as an an'sep'c or disinfectant.  Halogen Iodophores Efforts to reduce unwanted aspects of tinctures have led to the introduction of tamed iodines, known as iodophores. Povidon-iodine In this preparation, iodine is dissolved in surfactants, which allows it to remain undivided. The use of this product allows the slow and continuous release of free iodine for germicidal action. Iodophores have a similar spectrum of activity to aqueous solution; are less irritating, allergic, corrosive and discoloring  Halogens Iodophores For maximum killing effect and minimal toxicity, it is necessary to dilute correctly to 1% -2% iodine solution. More concentrated solutions are in fact less effective, possibly due to stronger complexation, which prevents the free release of iodine. The release of free iodine requires a contact time of about 2 minutes. Iodophores are fast bactericides, virucides and mycobactericides, but longer contact times may be required to kill certain fungi and bacterial spores. Iodophores formulated as antiseptics are not suitable as hard surface disinfectants due to insufficient iodine concentration. Iodine has ability to be absorbed systemically through the skin and mucous membranes. The degree of absorption is related to the concentration used, the frequency of use and the state of renal function (major route of excretion). Complications of iodophor absorption include renal failure, metabolic acidosis, and elevated serum iodide levels. If renal function is normal, serum iodine levels return to normal rapidly. Clinical hyperthyroidism and thyroid hyperplasia have been reported following PI treatment.  Halogens Chlorine Chlorine-containing solutions were first introduced in the early 1900s as sodium hypochlorite. They are effective bactericides, fungicides, virucides and deadly to protozoa. Today, the most commonly used chemical forms are hypochlorites (sodium and calcium) and organic chlorides (chloramine-T). In any form, germicidal activity is associated with the release of free chlorine and the formation of hypochlorous acid (HOCl) from water. Mechanisms of action include inhibition of cellular enzymatic reactions, protein denaturation and nucleic acid inactivation. Low concentrations of free chlorine are active against M. tuberculosis and vegetative bacteria within a few seconds. High concentrations kill fungi in less than 1 hour, and many viruses are inactivated within 10 minutes at high concentrations. Household bleach is 5.25%; thus, dilutions of 1: 100 to 1: 250 should be effective germicides, although more concentrated solutions (1:10 to 1: 100) are often recommended.  Halogens Hypochlorites The use of hypochlorite as a disinfectant is limited by several properOes. Chlorine soluOons are corrosive to metals and destroy many fabrics. Unstable to light, they should be prepared fresh daily. Hypochlorites are inac1vated more than organic chlorides by the presence of blood. They have a strong odor and are not suitable for confined spaces. Hypochlorites can cause mucosal irrita1on and may form toxic bioproducts when interacOng with other chemicals. Despite these shortcomings, chlorine soluOons are commonly used as low-level disinfectants in dairy facili1es, animal housing, hospital floors and other non-cri1cal items. Of the 12 disinfectant solu=ons evaluated for their ability to kill the dermatophyte Microsporum canis, the most effec=ve were those containing hypochlorite. Hypochlorites are not recommended for daily use as an1sep1cs because they are very irrita1ng to the skin and other 1ssues and delay healing. There are studies showing that diluted household bleach can be used to control superficial pyoderma in dogs.  Biguanides Chlorhexidine is a popular synthetic cationic antiseptic compound with better activity against gram-positive than against gram-negative organisms. It is active against fungi, quite active against M. tuberculosis, but poorly active against viruses. The compound lacks sporicidal activity. Chlorhexidine kills bacteria by breaking down the cell membrane. Antibacterial activity is not as rapid as that of alcohols; however, as a 0.1% aqueous solution, significant germicidal activity is seen after 15 seconds. In addition, chlorhexidine solutions have the longest lasting activity, persist for 5-6 hours and retain their activity in the presence of blood and other organic materials. As a cation, it is inactivated by hard water, non-ionic surfactants, inorganic anions and soaps. The operation depends on the pH. It has extremely low toxicity. Chlorhexidine is available as a detergent as a 4% solution or as a 2% liquid foam. Widely used as a preoperative detergent and antiseptic, wound healing agent. Chlorhexidine and alcohol preparations that appear to improve efficacy have also been described. May be allergic and cause skin irritation  Biguanides Polyhexamethylene biguanide (PHMB) is a polymeric biguanide with activity against gram-positive and gram- negative bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and Streptococcus equi. PHMB rapidly kills bacteria by disrupting the cytoplasmic membrane. PHMB is used to treat eye, mouth and vaginal infections and is also formulated as a surface disinfectant as a mouthwash and contact lens disinfectant. Not corrosive  Aldehydes Formaldehyde The two aldehyde disinfectants used are formaldehyde and glutaraldehyde. Formaldehyde has antimicrobial activity both as a gas and in liquid form. 37% of formaldehyde is formalin. It inactivates microorganisms by alkylating the amino and sulfhydryl groups of the protein and the nitrogen atoms of the purine base ring. Formaldehyde is an effective but slow bactericide, virucide and fungicide that requires a contact time of 6-12 hours. It is effective against M. tuberculosis, bacterial spores and most animal viruses, including the foot- and-mouth disease virus. Organic substances does not affect its performance and is relatively non-corrosive to metals, paint and fabric. Formaldehyde is considered a high-level disinfectant and can be used in combination with alcohol as a chemical sterilizer for surgical instruments. However, due to irritating and pungent odors at low concentrations and possible carcinogenic properties, the use of formaldehyde as a disinfectant is limited.  Aldehydes Glutaraldehyde Glutaraldehyde, a saturated dialdehyde, is similar to formaldehyde, but without some of its disadvantages. BeCer bactericidal, virucidal and sporicidal ac(vity than formaldehyde. Its biocidal ac'vity is related to the ability to alkylate sulLydryl groups, hydroxyl groups, carboxyl groups and amino groups, which affect the synthesis of RNA, DNA and proteins. Acid glutaraldehyde soluCons are not sporicides; thus, they must be "acCvated" by alkalizing agents up to a pH of 7.5 to 8.5. Glutaraldehyde has gained widespread recogni'on in high-level disinfec(on and chemical steriliza(on due to a number of beneficial proper'es, including a wide range of ac'vi'es. It retains its biocidal ac(vity in the presence of organic substances.  Aldehydes Glutaraldehyde It is non-corrosive to metal, rubber and plastic and does not damage lens instruments. Glutaraldehyde solutions should be used in well-ventilated areas as air concentrations are irritating to the eyes and nasal passages. Using a 2% aqueous solution of alkaline glutaraldehyde took less than 2 minutes to kill the vegetative bacteria, 10 minutes for the fungi and 3 hours for the bacterial spores. The activity against the tuberculosis agent was found to be slightly variable; it takes at least 20 minutes at room temperature to safely kill these organisms with 2% glutaraldehyde. When used as a high level disinfectant, at least 1% glutaraldehyde should be used. Glutaraldehyde disinfectants have been shown to be more effective if they contain additives such as alcohol and ammonium chloride derivatives.  Oxidizing compounds Hydrogen peroxide It has been reported to have bactericidal, virucidal and fungicidal effects. As 3% hydrogen peroxide has been shown to damage tissues, including fibroblasts, it is not considered suitable for daily wound care. It is considered a stable and effective disinfectant. Accelerated hydrogen peroxide products have been developed that contain a stabilizer and enhance antimicrobial activity These products are introduced in many veterinary clinics for use as a disinfectant.  Oxidizing compounds Potassium per-oxy-mono-sulphate oxidizer used for disinfection of swimming pools and hot tubs. It was developed with potassium chloride and organic acids and salts to produce a disinfectant that is effective against more than 580 infectious agents, including viruses, gram-positive and gram-negative bacteria, fungi and mycoplasmas. It is sold as a powder because it is stable in solution for about 1 week. Organic substances do not affect its operation, safe for use in both humans and animals. It is widely used as a high-level disinfectant for laboratory, dental and hospital surfaces, laundry cleaning, air disinfection, food-water processing.  Phenols Phenol carboxylic acid is the oldest an'sep'c compound used. Due to its severe toxicity, it is no longer suitable for use as an an'sep'c. Acts as cytoplasmic destroyers by penetra'ng and disrup'ng microbial cell walls. Most commercially available phenolic products contain two or more compounds that act synergis'cally, resul'ng in a broader spectrum of ac'vity, including against M. tuberculosis. Sodium o-phenylphenol is effec've against staphylococci, pseudomonas, mycobacteria, fungi and lipophilic viruses, as well as ascarids, strongyls and lice.  Phenols Cresols are substituted phenols and are more bactericidal, less toxic and corrosive than phenols. Phenols are not recommended for use in disinfection, except for non-critical items, due to disinfectant residues on porous materials, which subsequently cause tissue irritation, even if the products are thoroughly rinsed, due to strong odors and absorption in feed. Triclosan is bisphenol with high antibacterial activity, especially against many Gram-positive (eg Bacillus, Mycobacterium, Staphylococcus aureus) and Gram-negative bacteria (Escherichia, Salmonella, Shigella). Pseudomonas mostly resistant!