Expanding the Variety of Pyridinium-Based bis-QACs with Antimicrobial Properties: Investigation into Linker Structure-Activity Correlation.

For decades quaternary ammonium compounds (QACs) have served as main component of a top antiseptic and disinfectant compositions. Among them, bis-QACs are the most prominent and effective class of biocides. Although mono-QACs still dominate the antiseptic market, their activity against Gram-negative bacteria is largely inferior to bis-QACs.

Development of Naphthalene-Derivative Bis-QACs as Potent Antimicrobials: Unraveling Structure-Activity Relationship and Microbiological Properties.

While the pandemic is behind us, the world community faces a global threat of bacterial resistance outbreak. One of the key ways to combat the spread of multi-resistant bacteria is infection prevention and control tactics using modern antiseptic and disinfectant compositions. Herein, we continue the path to unravel the structure-activity relationship (SAR) of potent pyridine-derived biocide class bis-quaternary ammonium compounds (QACs).

Hetero-Pathogenic O181:H4 EAHEC Strain of Sequence Type ST678 Associated with Hemolytic-Uremic Syndrome in Schoolchildren in Russia.

Background: In the last decade, the importance of hetero-pathogenic enteroaggregative Shiga-toxin-producing for public health has increased. Recently, we described the genetic background of the EAHEC O181:H4 strain of ST678 carrying the gene in prophage and five plasmids, including the plasmid-carrying and genes. Here, we present the morphological and enzymatic characteristics of this strain, as well as susceptibility to antimicrobials, biofilm formation, etc.

The Antimicrobial and Antibiofilm Potential of New Water-Soluble Tris-Quaternary Ammonium Compounds.

The invention and innovation of highly effective antimicrobials are always crucial tasks for medical and organic chemistry, especially at the current time, when there is a serious threat of shortages of effective antimicrobials following the pandemic. In the study presented in this article, we established a new approach to synthesizing three novel series of bioactive water-soluble tris-quaternary ammonium compounds using an optimized one-pot method, and we assessed their antimicrobial and antibiofilm potential. Five pathogenic microorganisms of the ESKAPE group, including highly resistant clinical isolates, were used as the test samples.

Multicationic Quaternary Ammonium Compounds: A Framework for Combating Bacterial Resistance.

During previous stages of research, high biocidal activity toward microorganism archival strains has been used as the main indicator in the development of new antiseptic formulations. Although this factor remains one of the most important characteristics of biocide efficiency, the scale of antimicrobial resistance spread causes serious concern. Therefore, focus shifts toward the development of formulations with a stable effect even in the case of prolonged contact with pathogens.

Microbiological Evaluation of Novel Bis-Quaternary Ammonium Compounds: Clinical Strains, Biofilms, and Resistance Study.

This work is devoted to the investigation of biocidal properties of quaternary ammonium compounds (QACs) based on pyridine structures with aromatic spacers, and their widely known analogs, against clinically significant microorganisms. This study is focused on investigating their antimicrobial activity (minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs)), antibiofilm properties (minimum biofilm inhibitory concentrations (MBICs) and minimum biofilm eradication concentrations (MBECs)), synergetic effect with different alcohols in antiseptic formulations, and bacterial resistance development. It was shown that all combined analogue preparations had a higher level of antibacterial activity against the tested bacterial strains, with a 16- to 32-fold reduction in MICs and MBCs compared to previously used antiseptic preparations.

Drug Repurposing of the Unithiol: Inhibition of Metallo-β-Lactamases for the Treatment of Carbapenem-Resistant Gram-Negative Bacterial Infections.

The increasing antibiotic resistance is a clinical problem worldwide. Numerous Gram-negative bacteria have already become resistant to the most widely used class of antibacterial drugs, β-lactams. One of the main mechanisms is inactivation of β-lactam antibiotics by bacterial β-lactamases.

The sensitivity of planktonic cultures and biofilms of gram-negative bacteria to commercial disinfectant and antiseptic preparations.

The in vitro antibacterial activity of 11 commercial disinfectant preparations and 8 antiseptics against 10 strains of the bacteria Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloaceae and Providencia stuartii obtained from international collections and isolated from neuroresuscitation patients in Moscow in 2018 was studied. The sensitivity of planktonic cultures to the preparations was determined by the method of serial dilutions in broth and the spot method on solid nutrient media, the sensitivity of biofilms by the applicator method. A general pattern was revealed: the level of sensitivity to tested disinfectants in clinical strains was lower than in reference strains.