Susceptibility of multidrug resistant clinical pathogens to a chlorhexidine formulation

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Multidrug-resistant (MDR) pathogens pose a significant threat in hospital environments, particularly in intensive care units (ICUs).
• The emergence of extensively drug-resistant (XDR) gram-negative organisms, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE) necessitates effective antimicrobial strategies.

Purpose of the Study:

• To evaluate the in vitro susceptibility of clinical isolates of XDR gram-negative organisms, MRSA, and VRE to a proprietary chlorhexidine digluconate (CHG) formulation.
• To assess the efficacy of CHG-impregnated cloths containing this formulation against these challenging pathogens.

Main Methods:

• Ten clinical isolates each of XDR Pseudomonas aeruginosa, XDR Acinetobacter baumannii, XDR Klebsiella pneumoniae, XDR Escherichia coli, MRSA, and vancomycin-resistant Enterococcus faecium were tested.
• Susceptibility was determined using time-kill assays and minimum inhibitory concentration (MIC) determination for the proprietary CHG formulation at concentrations of 0.5%, 1%, and 2%.

Main Results:

• All tested isolates, including XDR gram-negative bacteria, MRSA, and VRE, were susceptible to the proprietary CHG formulation.
• Time-kill assays showed 99% to 100% growth suppression within 1 minute for gram-positive and 15 seconds for gram-negative organisms.
• MIC values indicated potent activity, with a wide range of dilutions demonstrating inhibition of microbial growth.

Conclusions:

• The proprietary CHG formulation used in CHG-impregnated cloths provides effective in vitro protection against colonization and infection by a range of critical hospital pathogens.
• This formulation is a promising agent for infection control strategies targeting XDR gram-negative organisms, MRSA, and VRE in healthcare settings.