When used properly , disinfectants have been shown to be effective in reducing microbial contamination and preventing infections , which are particularly important in healthcare settings . Their uses are essential in high-risk settings such as healthcare facilities in the current pandemic given the large numbers of patients routinely admitted to these facilities and workers at potential risks of exposure to contaminated surfaces or objects . A more cautious approach , however , is needed to weigh the risks and benefits of their prolonged and often non-discriminated use in other low-risk settings .”
– Chen , et al . ( 2021 ) of these compounds , which can be either intrinsic or acquired , has been observed on various bacterial pathogens .”
As Chen , et al . ( 2021 ) confirm , there are more than 500 EPA-approved chemical disinfectant products for COVID-19 disinfection , and among them , the most used biocidal agents account for two-thirds of the active ingredients found in current EPA-approved disinfectants . More importantly , almost 81 percent of the disinfectant products use only one biocidal agent , while the rest of them use two or more in their formulation . The problem with that narrow spectrum of products is that “ The lack of diversity of active ingredients used in these products increases the likelihood of exposing bacteria to the same type of biocidal agents over and over again on a regular basis , under the current practices of regular disinfecting of contact surfaces in community and public settings during COVID-19 ,” the researchers emphasize .
Numerous studies indicate that many types of bacterial pathogens have shown the ability to adapt and develop increased tolerance to biocidal agents , including the four major active ingredients used in products listed by EPA for COVID-19 .
As we know , bacterial mutations can be driven by selective pressure exerted by antimicrobials ( including disinfectants ), which could contribute to the development of increased tolerance .
“ The data appears to indicate that this can occur due to bacterial horizontal gene transfer , upregulation of efflux pumps , membrane alteration , and biofilm formation as common mechanisms conferring biocide tolerance in bacteria ,” Rohde says .
Chen , et al . ( 2021 ) emphasize that , “ A substantial body of published literature has described the linkage between the use of chemical disinfectants and the growth of antibiotic resistance in some bacteria ,” and adding that , “ The association between chronic sublethal exposure to biocidal agents and promoted antibiotic resistance has been demonstrated unequivocally in laboratory studies , although real-world situations are often more complicated . Many field studies have been conducted to explore whether there was indeed a correlation between disinfectant use and antibiotic resistance .”
The researchers continue , “ Overall , current evidence suggests that disinfectant-induced antibiotic resistance is more likely to become a contributing factor when bacteria are repeatedly exposed to subinhibitory concentrations of biocidal agents in disinfectants . This is plausible given that in practice , the concentration of biocides will be in a continuous gradient from zero to the treatment concentration . Meanwhile , the actual uses of disinfectants by un-trained individuals and the wide variety of receiving surfaces and environments differ from an ideal situation , and many factors could affect the disinfection efficacy , potentially leading to subinhibitory concentration exposure . Common risk factors include inadequate cleaning of the surface to be disinfected , materials with porous or complex internal structures that are difficult to access , presence of biofilms , and failure to follow instructions during product storage and use . A lesser-known risk factor in disinfectant-induced antibiotic resistance is that some disinfection byproducts ( DBPs ) – intermediates often generated in chemical disinfection processes – can have mutagenic activities and contribute to the emergence of antibiotic resistance in microbes . Experiments using three commonly occurring DBPs , namely , trichloroacetic acid , chlorite , and iodoacetic acid , demonstrated that the latter two compounds had antibiotic-like effects and induced antibiotic resistance at both high ( near MICs ) and low levels ( ca . 3 % of MICs ).”
It is generally accepted that disinfectants and antiseptics should be used when there is scientific evidence demonstrating the benefits of use or when there is a strong rationale for doing so . As Chen , et al . ( 2021 ) explain , “ When used properly , disinfectants have been shown to be effective in reducing microbial contamination and preventing infections , which are particularly important in healthcare settings . Their uses are essential in high-risk settings such as healthcare facilities in the current pandemic given the large numbers of patients routinely admitted to these facilities and workers at potential risks of exposure to contaminated surfaces or objects . A more cautious approach , however , is needed to weigh the risks and benefits of their prolonged and often non-discriminated use in other low-risk settings . The constant selective pressures exerted by over a handful of disinfecting agents would inevitably give rise to bacteria that can survive in these environments , and consequently increase the risk of exposure to biocide-tolerant and drug-resistant bacteria for people living by or contacting with these surfaces . Despite the current widespread practice , reports evaluating the correlation between disinfectant use and potential induction of bacterial tolerance or resistance in community-relevant environments are scarce . To date , there has been no study or scholarly discussion on the risk of antimicrobial resistance emerging from the regular use of chemical disinfectants on common touch surfaces in community or public settings , revolving around the current practices during the COVID-19 pandemic or the EPA-approved disinfectants . Pertinent data and findings suggest that one probably should not neglect the emerging risk of community outbreaks of antimicrobial bacteria as unintended consequences of the wide and regular use of chemical disinfectants in a persisting pandemic .”
It is important to note that disinfectants are often used at concentrations considerably higher than minimum inhibitory concentrations ( MICs ) or minimum bactericidal concentrations ( MBCs ) to achieve rapid killing , and it is unlikely for bacteria to survive and develop resistance under normal circumstances , according to experts . As Chen , et al . ( 2021 ) note , “ The antibiotic