[Increased growth of chemotherapy-resistant hospital organisms through disinfection (author's transl)]

Area of Science:

• Microbiology
• Hospital Epidemiology
• Antimicrobial Resistance

Background:

• A hospital strain of Proteus rettgeri from Munich exhibits resistance to both chemotherapy and mercury ions.
• This resistance is linked to a specific R-factor plasmid.
• The strain shows reduced sensitivity to phenylmercuric borate, a key component in the disinfectant Merfer.

Purpose of the Study:

• To investigate the co-occurrence of chemotherapy and mercury resistance in a hospital strain.
• To assess the implications of mercury resistance for disinfectant efficacy.
• To discuss the role of disinfectants in selecting for resistant bacterial strains.

Main Methods:

• Plasmid analysis to identify resistance determinants.
• Antimicrobial susceptibility testing against chemotherapy agents and mercury compounds.
• Discussion of epidemiological significance.

Main Results:

• The Proteus rettgeri strain possesses an R-factor conferring resistance to chemotherapy and mercury ions.
• Strains with this R-factor are less susceptible to phenylmercuric borate.
• This highlights a potential link between disinfectant use and the selection of resistant bacteria.

Conclusions:

• Disinfectants containing mercury may inadvertently select for chemotherapy-resistant bacteria.
• The widespread use of mercury in disinfectants poses risks for public health.
• It is recommended to discontinue the use of mercury as an active ingredient in disinfectants.