Inside the Operating Theatre
Manoj Ramachandran, Tom Nunn in Basic Orthopaedic Sciences, 2018
Antiseptics are disinfectants used in living tissue. Their use results in a reduction in the number of viable organisms but not the complete destruction of all viable micro-organisms; unlike the process of sterilization, some viruses and bacterial spores may remain. Three solutions are commonly used for hand washing and skin antisepsis prior to surgery: Iodophors: iodine complexed with solubilizing agent, such as povidone, resulting in free iodine release when in solution. They are potent, broad-spectrum and rapidacting bactericidal agents, also active against spores, fungi and viruses, but inactivated by blood, faeces and pus. They work through the destruction of microbial proteins and deoxyribonucleic acid (DNA). They may be irritant and cause hypersensitivity reactions. In aqueous form, they are safe on open wounds and mucous membranes.Alcohols: used in 70% concentration, rapidly active against a broad spectrum of gram-negative and gram-positive bacteria. They have some antiviral activity but are relatively inactive against spores and fungi. They work by evaporation and protein denaturation, but have no residual activity. Use on open wounds and mucous membranes is contraindicated.Chlorhexidine: a bisbiguanide compound with bactericidal and bacteriostatic activity against a broad spectrum of gram-positive and gram-negative bacteria, fungi, and lipophilic viruses. It acts through membrane disruption. It is deactivated by many topical skin products, cleansers and hand sanitizers; it is active in the presence of blood, soap and pus, but its effectiveness may be reduced. Use on mucous membranes or in body cavities is contraindicated. Pseudomonas may grow in stored contaminated solutions.
Tolerance to disinfectants (chlorhexidine and isopropanol) and its association with antibiotic resistance in clinically-related Klebsiella pneumoniae isolates
Published in Pathogens and Global Health, 2021
Jasmine Morante, Antonio M. Quispe, Barbara Ymaña, Jeel Moya-Salazar, Néstor Luque, Gabriela Soza, María Ramos Chirinos, Maria J Pons
Biocides are routinely used in healthcare settings and play an essential role in infection control [1], one that has been highlighted during the fight against SARS-CoV-2. Two of the most frequently used types of biocides in hospitals are chlorhexidine digluconate (CHG) and isopropyl alcohol (ISP). Chlorhexidine is a bisbiguanide antiseptic used against a wide range of microorganisms. It functions by forming a bridge between phospholipids with subsequent displacement of cations (Mg2+ and Ca2+) [2], resulting in membrane disruption via a reduction in the capacity of the bacterial membrane to osmoregulate and changes in enzymes associated with metabolic membrane capability [2]. Chlorhexidine is often used for procedures such as handwashing, preoperative preparation, and surface disinfection because of its bacteriostatic and bactericidal properties [3,4], as well as its ability to rapidly denature the proteins of microorganisms [5].
Effects of a sub-minimum inhibitory concentration of chlorhexidine gluconate on the development of in vitro multi-species biofilms
Published in Biofouling, 2020
Yuki Suzuki, Tatsuya Ohsumi, Toshihito Isono, Ryoko Nagata, Taisuke Hasegawa, Shoji Takenaka, Yutaka Terao, Yuichiro Noiri
In order to control the growth of cariogenic biofilms, the application of antimicrobial agents, such as chlorhexidine gluconate (CHG) and essential oils, has been widely adopted (Sreenivasan and Gaffar 2002). CHG is a cationic bisbiguanide that involves a broad spectrum of antibacterial activity. It has been proved to be a safe and stable substance that is effective in reducing the viability of biofilm-forming bacteria (Jones 1997; Van Strydonck et al. 2012). The main function of such antimicrobial agents is bactericidal in nature (Koo and Jeon 2009). Antibiotics are effective agents against bacterial pathogens when their concentrations are higher than the minimum inhibitory concentration (MIC). However, the use of bactericidal agents can lead to a disruption in the resident microflora and the establishment of exogenous species, which can result in pathological changes (Marsh 1992). Therefore, a chemotherapeutic approach aimed at reducing the growth and virulence properties of bacteria in antibiotic concentrations below the MIC, which is defined as sub-minimum inhibitory concentrations (sub-MIC), was investigated.
Diagnostics and management approaches for Acanthamoeba keratitis
Published in Expert Opinion on Orphan Drugs, 2020
Nóra Szentmáry, Lei Shi, Loay Daas, Berthold Seitz
Chlorhexidin (C22H30Cl2N10) is a bisbiguanide compound with a structure consisting of two (p-chlorophenyl) guanide units linked by a hexamethylene bridge and is also a member of monochlorobenzenes. It has topical antibacterial activity and is implemented as an antiseptic agent. As Chlorhexidine is positively charged, it reacts with the negatively charged microbial cell surface and thus destroys the integrity of the cell membrane. Consequently, the substance penetrates into the cell, causes leakage of intracellular components, and ultimately results in cell death. Gram-positive bacteria are more sensitive to this agent as they have a higher negative charge. It is indicated for the reduction of pocket depth in patients with adult periodontitis, used as an adjunct to scaling and root planing procedures. Further usage also includes the prevention of dental caries, oropharyngeal decontamination in critically ill patients, hand hygiene in health-care personnel, general skin cleanser, as well as catheter site preparation and care. Furthermore, it is specified in its drug warning to keep the substance out of eyes, ears, and mouth.
Related Knowledge Centers
- Antiseptic
- Biguanide
- Guanidine
- Chlorhexidine
- Alexidine