Related Experiment Video
Updated: Jun 14, 2025
Culturing and Maintaining Clostridium difficile in an Anaerobic Environment
Published on: September 14, 2013
An in-depth study on survival mechanism of bacterial isolates in disinfectants within the hospital environment
Pue Rakshit1, Aradhana Singh1, Ravindra Singh2
1Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Introduction:
The emergence of disinfectant resistance has become a severe threat due to reduced effectiveness. This study was undertaken to determine how bacteria adapt to survive exposure to disinfectants in the busiest section of a tertiary care hospital in Varanasi, India.
Methods:
Four isolates (two Klebsiella pneumoniae, Kp1 and Kp2; two Pseudomonas aeruginosa, Pa1 and Pa2) were obtained from chlorhexidine (CHX)-based handwash during microbiological surveillance of "in-use disinfectants" in hospital. Six disinfectants [4% CHX, 2% glutaraldehyde, 7.5% hydrogen peroxide, 1% sodium hypochlorite and 0.1% benzalkonium chloride (BAC), and 70% ethyl alcohol] were tested against these four isolates to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Antibiotic profile, change in MIC on exposure to disinfectants and biofilm formation in the presence and absence of disinfectants was studied. Whole genome sequencing (WGS) was done to identify the resistance mechanisms.
Result:
The isolates showed the highest MBC/MIC ratio (4) against glutaraldehyde. Exposure to supra-inhibitory concentration of BAC for 21 days resulted in doubling of MIC/MBC. The majority (75%) of the isolates were multidrug resistant. All the isolates were strong biofilm producers. The reduction rate of biofilm formation decreased with an increase in the concentration of disinfectants (p = 0.05 for BAC). WGS revealed multiple AMR genes including bla DIM-1, disinfectant-resistant gene and efflux pump genes.
Conclusion:
The study emphasized the various adaptation strategies of these isolates for survival in disinfectant environment, thus posing a huge challenge for their control in the hospital environment.
More Related Videos
Related Concept Videos
01:30Cleaning, Sterilization, and Disinfection
Cleaning
The cleaning process usually involves using water with detergents or enzymatic cleaner and removing foreign material from objects and surfaces, including organic material such as body fluids or inorganic material like soil. Cleaning is performed before high-level disinfection and sterilization because foreign materials on the cover of the devices interfere with process...
01:31Defense Against Bacterial Pathogens
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
01:26Defense Mechanism Against Infection
In addition, many body organ systems have unique defenses against infection. The skin is an intact, multilayered surface preventing invasion by microorganisms unless impaired. Mucous membranes lining the mouth, nose, and eyelids are barriers...
01:23Hand hygiene
Hand washing...
01:29Methods of Sterilization I: Physical Methods
Steam sterilization uses non-toxic, low-cost moist heat in the form of saturated steam under pressure, which is fast, microbicidal, and sporicidal, and quickly warms and penetrates fabrics. Autoclaves, or steam sterilizers, expose each item to direct steam contact for a predetermined time at the necessary...
01:18Surface Membrane Barriers
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...