• Bacterial Resistance to Antimicrobial Biocides: an insight into molecular mechanisms
  • Malek Namaki Kheljan,1,* Malihe Hasanzadeh,2 zohreh neyestani,3 parastoo ashuri,4
    1. Department of Microbiology, School of Medicine, Ardabil university of medical sciences, Iran
    2. Department of Biology, Ardabil Branch Islamic Azad University, Ardabil, Iran
    3. Department of Microbiology, School of Medicine, Ardabil university of medical sciences, Iran
    4. Department of Microbiology, School of Medicine, Ardabil university of medical sciences, Iran


  • Introduction: Antimicrobial Biocides are extensively employed as preservatives, disinfectants, and sterilizers in hospitals, industry, and the household. Antimicrobial Biocides are commonly used to eliminate bacteria from the surfaces of objects, transmission media, and surfaces. Iodophors, quaternary ammonium compounds, peroxides, phenols, chlorides, and glutaraldehyde are the six primary groups of Antimicrobial Biocides utilized in hospitals worldwide. In clinical settings, the most prevalent antiseptic and disinfectant biocides are chlorhexidine digluconate (a biguanide that disrupts the cell membrane), benzalkonium chloride (a quaternary ammonium compound that disrupts the cell membrane), triclosan (a bisphenol that blocks lipid biosynthesis), and formaldehyde (an aldehyde, alkylating agent). Reduced susceptibility of bacteria to antimicrobial biocides results from the selection pressure resulting from the bacteria's continuous use and recurrent exposure to substances employed to increase their productivity. Due to the diminished efficiency of antimicrobial biocides, antimicrobial biocides resistance has become a serious threat to life and health and the logical use of resources. This factor restricts their usage as antimicrobials. Several outbreaks of nosocomial infections have been attributed to tainted biocide solutions. A second problem is the paucity of data linking biocide tolerance and resistance to certain medically necessary antibiotics. Multiple investigations have demonstrated bacterial resistance to various biocides due to the presence of resistance genes. Resistance to Antimicrobial Biocides is caused either by the acquisition of foreign mobile genetic elements or by an innate genetic adaptation process. This article examined the resistance mechanisms of Antimicrobial Biocides-resistant bacteria on biofilms, cell membrane permeability, efflux pumps, degradable enzymes, and disinfectant targets. Efflux might be the quickest and most efficient stress resistance mechanism for bacteria. The Qac genes, which are situated on some plasmids that might transmit resistance by conjugative transfer, are the most often reported Antimicrobial Biocides resistance genes. Uncertainty remains about whether the Qac genes can be transmitted via transformation or transduction. Studying the variables influencing bacterial resistance to antimicrobial biocides can lead to the discovery of innovative solutions to the problem of decreasing antimicrobial biocide efficacy. It has been established that the interaction between probiotics and bacteria, as well as the addition of 4-oxazolidinone, can suppress the production of biofilms.
  • Methods: Different databases such as Google Scholar, PubMed, Scopus and Web of Science were searched.
  • Results: Studies have shown that there is a significant relationship between molecular mechanisms and antimicrobial biocides resistance.
  • Conclusion: By decreasing the expression of efflux pumps, chemicals such as eugenol and indole derivatives might enhance bacterial sensitivity. The significance of these discoveries in anti-Biocide resistance has been established.
  • Keywords: Bacterial Resistance ; Antimicrobial Biocides; molecular mechanisms