Effects of chlorhexidine gluconate on the development of spores of Bacillus subtilis

  title={Effects of chlorhexidine gluconate on the development of spores of Bacillus subtilis},
  author={A. G. Knott and A. Denver Russell},
  journal={Letters in Applied Microbiology},
The effects of sublethal concentrations of the membrane‐active agent chlorhexidine gluconate (CHG) on the growth rate and sporulation of Bacillus subtilis vegetative MB2 cells have been investigated. CHG increased the mean generation time (Mgt) of vegetative cells in casein medium. It also affected spore development: as CHG concentrations increased, spore index (SI) values decreased and sensitivity to both toluene and heat increased. 

Non‐variable sources of pure water and the germination and outgrowth of Bacillus subtilis spores

Variable germination and outgrowth occurred when Bacillus subtilis NCTC 8236 spores were inoculated into nutrient broth prepared with distilled water, a technique of value in monitoring the development of resistance to antibacterial agents during sporulation.

Enhanced sporulation in Bacillus subtilis grown on medium containing glucose:ribose

Spore crops obtained from cultures grown on glucose:ribose had similar thermal resistance and hydrodynamic mean radius to those obtained when cultivated solely on glucose‐ or ribose‐containing media.

Similarities and differences in the responses of microorganisms to biocides.

  • A. Russell
  • Biology, Environmental Science
    The Journal of antimicrobial chemotherapy
  • 2003
Unlike antibiotics, biocides are multi-targeted antimicrobial agents. Several of the damaging effects reported to occur in the most widely studied organisms, bacteria, may also take place to varying

Factors affecting the activities of microbicides

This chapter is a general review on how the above-mentioned factors may influence the microbicidal activity of chemicals during the initial development of a given formulation, its actual field use and in assessing the outcome of its application.

Antiseptics and Disinfectants: Activity, Action, and Resistance

Known mechanisms of microbial resistance (both intrinsic and acquired) to biocides are reviewed, with emphasis on the clinical implications of these reports.

Microbial differentiation and changes in susceptibility to antimicrobial agents

Differences in response to biocides may be ascribed to the variation in structure and chemical composition of various types of micro-organisms as well as to the manner in which the uptake of an antimicrobial agent into a cell is thereby inenced.

Understanding microbial survival in, and the development of resistance to, high-level disinfection

It is demonstrated that bacteria can survive high-level disinfection with oxidising agents and that mechanisms conferring resistance are complex but might not be linked to impaired biocide penetration.

Chlorhexidine--pharmaco-biological activity and application.

Chlorhexidine play a valuable role in the dentistry and antisepsis, however, it can also cause side effects, limiting its application time and its activity depends on the pH of the environment and the presence of organic substances.

Mechanisms of bacterial resistance to antibiotics and biocides.

  • A. Russell
  • Biology
    Progress in medicinal chemistry
  • 1998



Emergence and development of chlorhexidine resistance during sporulation of Bacillus subtilis 168

During sporulation of Bacillus subtilis strain 168 initiated by step-down conditions, resistance to chlorhexidine diacetate developed at about t3.5, before heat but after toluene resistance, likely a result of spore coat, rather than of cortex, development.

Bacterial spores and chemical sporicidal agents.

  • A. Russell
  • Biology
    Clinical Microbiology Reviews
  • 1990
Mechanisms of spore resistance to, and the action of, biocides are discussed, and possible means of enhancing antispore activity are considered.

Ethanol sensitivity of sporulation in Bacillus subtilis: a new tool for the analysis of the sporulation process

The growth rate of Bacillus subtilis is lowered but the final cell yield is unchanged when certain concentrations of ethanol are present in the culture medium, and in effect, ethanol is turning wild-type cells into phenocopies of spoO mutants.

Emergence of resistance to glutaraldehyde in spores of Bacillus subtilis 168

Studies with sporulation mutants also indicate that glutaraldehyde resistance is acquired even later than lysozyme resistance and may therefore possibly be considered as a very late marker event for sporulation, characterizing late stages of B. subtilis 168 spore formation.

Alcohol-resistant sporulation mutants of Bacillus subtilis

The extensive, pleiotropic changes in the membranes of ssa mutants are the phenotypic reflection of alterations at a specific gene locus, identified as ssa mutations, which differ from wild-type cells in the composition of membrane phospholipids.

Commitment to sporulation in Bacillus subtilis and its relationship to development of actinomycin resistance.

It is shown that sporulation and growth are perhaps not mutually exclusive functions and that histidase, an enzyme typical of the vegetative state, can be induced in sporulating suspensions.

Principles and Practice of Disinfection, Preservation and Sterilization

principles and practice of disinfection, preservation and principles and practice of disinfection preservation and principles and practice of disinfection preservation and principles and practice of