Monocationic surfactant induced ultra structural changes in antibiotic resistant Escherichia coli

Area of Science:

• Microbiology
• Infectious Diseases
• Hospital Epidemiology

Background:

• Cetrimide is a widely used monocationic surfactant for hospital disinfection and wound cleansing.
• Antibiotic resistance in nosocomial pathogens like Escherichia coli is a growing public health concern.
• The susceptibility of antibiotic-resistant E. coli to common disinfectants like cetrimide requires evaluation.

Purpose of the Study:

• To determine if antibiotic-resistant (AR) Escherichia coli isolates from hospital settings exhibit reduced susceptibility to cetrimide.
• To assess the ultrastructural changes induced by cetrimide in AR E. coli using transmission electron microscopy (TEM).

Main Methods:

• Isolation and identification of E. coli from 165 clinical samples.
• Antibiotic susceptibility testing to identify AR E. coli isolates.
• Determination of cetrimide's Minimum Inhibitory Concentration (MIC) and time-kill kinetics.
• Transmission electron microscopy (TEM) to observe cellular damage.

Main Results:

• The study isolated AR E. coli resistant to 12 different antibiotics.
• The MIC of cetrimide against AR E. coli was determined to be 312.5 µg/ml.
• TEM revealed dose- and time-dependent ultrastructural changes, including vacuole formation, nuclear material disorganization, cytoplasmic granularity loss, bleb formation, and cell lysis.

Conclusions:

• Antibiotic resistance in E. coli does not significantly alter susceptibility to cetrimide.
• Cetrimide remains an effective disinfectant against nosocomial E. coli pathogens.
• The observed ultrastructural damage highlights cetrimide's potent bactericidal activity.