Microbe resistant to disinfectants

Stone, W. et al. 2020. Disinfectant, Soap or Probiotic Cleaning? Surface Microbiome Diversity and Biofilm Competitive Exclusion.


  • The type and amount of the microbiome of hospital surfaces were studied when cleaning the surfaces for 8 months with different cleaning programs
    • soap-based cleaner
    • probiotic cleaner (only bacterial spores of the genus Bacillus) and
    • disinfectant (chlorine)
    • tap water as control

• on stainless steel, ceramic tile, and linoleum surfaces
• Staphylococcus aureus and E.coli were placed to the surfaces.

  • Wet wiping methods except for the probiotic, which was a ready-to-use solution: it was sprayed on the surface, after which the surface was wiped.
  • Cleaning twice a week
  • Test tiles were stored indoors and outdoors (on the roof of the building)
  • The microbial diversity and number of test surfaces were examined after 8 months, the cleaning wipes used were also examined
  • Pathogens (P. aerugonosa) were then added to the surfaces and microbial changes were examined.


  • The disinfectant reduced the amount of microbiota on the surfaces, which allowed room for the growth of pathogenic bacteria.
  • Soap did not reduce the number of microbes as much as the disinfectant.
  • When cleaned with soap, the microbiome was more diverse than when cleaned with a probiotic (perhaps because there is only one bacterial spore in the probiotic).
  • When the probiotic was cleaned, the amount of microbiome was significantly higher than when other substances were used, which prevented the growth of pathogens on the surfaces, but when biofilm on the surface, the probiotic-induced microbiome was not as effective as soap-induced microbiome.
  • 1-5 times more microbiomes on surfaces cleaned with probiotics than on other surfaces (order: disinfectant, soap, water, probiotic).
  • Microbial levels of cleaning wipes were higher than on surfaces.


  • The results support the notion that the surface microbiome can defeat pathogens.
  • Both the number and the diversity of the microbiome matter.
  • The use of soap and probiotics is possible in certain hospital settings.
  • Probiotics should potentially contain more than one species of bacteria.
  • No probiotics are needed at home.

Global AMR Insights Ambassador Network. 2021. The potential impact of the COVID-19 pandemic on global antimicrobial and biocide resistance: an AMR Insights global perspective.

An article of pandemic’s effect on global antimicrobial resistance (AMR)

  • Global infections due to antimicrobial resistant pathogens result in approximately 700 000 deaths annually, which has been estimated to increase to 10 million deaths by the year 2050. In 2019, ECDC reported the deaths of 25 000 patients in high-income countries of Europe.
  • While the emergence of AMR continues to increase, there has been a decline in the availability of newly developed antimicrobial agents. If this continues, most of the currently prescribed antibiotics applied for human and animal infections will be ineffective within a decade, leading to conditions similar to that of the pre-antibiotic era.

Increased use of biocides

  • Biocides = compounds with antiseptic, disinfectant or preservative activity.
  • Less is known about the mechanisms and extent of microbial resistance to biocides than is known about microbial resistance to antibiotics.
  • Improved hygiene practices involving biocides may actually reduce the transmission of antimicrobial-resistant pathogens that are found on our hands, but paradoxically may at the same time select for antimicrobial-resistant pathogens, thereby having an unknown impact on global AMR.
  • Surface disinfectants and household cleaners contribute to an increased concentration of these substances in wastewater treatment plants and receiving waters, altering the normal ecosystem, and potentially favouring the emergence of AMR due to biocide-related selection pressure.
  • The increased use of disinfectants may induce organisms to a viable but non-cultivable state, becoming undetectable using standard culture-based detection methods.