Czech J. Food Sci., X:X | DOI: 10.17221/201/2024-CJFS

Chlorhexidine dihydrochloride's effect on clinical, veterinary and food-origin Staphylococcus aureusOriginal Paper

Marta Štindlová ORCID...¹, Václav Peroutka ORCID...¹, Simona Lencová ORCID...¹, Kamila Zdeňková ORCID...¹

¹ Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Czech Republic

Chlorhexidine (CHX) is a bactericidal agent used as a common disinfectant since the 1950s. However, its effectiveness may have diminished over the time due to the rise of microbial resistance even among nonantibiotics. In this study, we evaluate the response of 46 Staphylococcus aureus isolates to CHXdihydrochloride according to their origin and phenotype (haemolysis induction, coagulase production, methicillin resistance and biofilm formation). Following classification, the influence of seven CHX concentrations (10.00–0.50 mg·L–1) on planktonic cell growth and biofilm formation was evaluated spectrophotometrically at 620 nm and 595 nm (24 h). Even though the effect of CHX was strain-specific irrespective of origin or phenotypic profile, concentrations above 2.50 mg·L–1 were almost uniformly determined as bactericidal. Although the non-bactericidal concentrations did not indicate any statistically significant differences, they did promote biofilm formation in some cases. Overall, our results suggest that CHX is still an effective disinfectant and an antimicrobial agent against S. aureus.

Keywords: staphylococci; disinfectant; chlorhexidine; antibacterial effect; biofilm formation

Received: October 21, 2024; Revised: May 30, 2025; Accepted: July 3, 2025; Prepublished online: September 30, 2025