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

Abstract

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. Moreover, hit-QACs demonstrated a stable effect against Gram-negative E. coli, K. pneumoniae, and A. baumannii within a month of incubation. Overall results indicated a high level of antibacterial activity of pyridine-based QACs.

N-alkylimidazole derivatives as potential inhibitors of quorum sensing in Pseudomonas aeruginosa

“…Moreso, in an event where the outer membrane is ruptured, there is the release of endotoxins that further contribute to the resilience of Gram-negative bacteria and hence makes them more resistant to antimicrobial agents [ 34 ]. It has recently been that novel bis-quaternary ammonium compounds were more active against Gram-positive bacteria in comparison to Gram-negative bacteria, similar to observations made here [ 35 ]. These outcomes also align with the findings of Kleyi and his team that reveal the marked ability of imidazole-based drugs to show activity against Gram-positive bacteria [ 36 ].…”

A Dicationic BODIPY-Based Fluorescent Bactericide to Combat Infectious Diseases and to Eradicate Bacterial Biofilms

“…These results could be explained by the structural differences between BOD-QU and BAC. BOD-QU has two cationic quaternary ammonium moieties and BAC has just one; thus, more cationic structures boost antibacterial efficiency against both Gram-positive and Gram-negative bacteria strains. , …”

“…BOD-QU has two cationic quaternary ammonium moieties and BAC has just one; thus, more cationic structures boost antibacterial efficiency against both Gram-positive and Gram-negative bacteria strains. 33,34 Unlike BOD-QU, BOD-QH does not have long alkyl chain which decreases its hydrophobicity leads to diminish its antibacterial effectiveness. It can be seen from Table 1 that BOD-QH does not have strong antibacterial effect in low MIC values which are not promising results for antibacterial studies.…”

From Antibacterial to Antibiofilm Targeting: An Emerging Paradigm Shift in the Development of Quaternary Ammonium Compounds (QACs)

“…Shtyrlin’s research group developed a library of broad-spectrum antibacterial QACs on the basis of pyridoxine, some of which also exhibited antibiofilm activity. , Thus, bis-QAC 6 and hybrid mono-QAC 7 with fatty acids as a tail fragment were superior in their microbiological properties to the widely known Russian antiseptic miramistin (Table ) and were at the same activity level as benzalkonium chloride (Table ). Vereshchagin and co-workers investigated the activity of QACs on the basis of pyridine structures with aromatic spacers against both Gram-positive ( S. aureus ) and Gram-negative ( E. coli , Klebsiella pneumoniae , P. aeruginosa , and A. baumannii ) biofilms . The minimum biofilm eradication concentrations of bis-pyridinium QACs ranged from 8 to 16 mg/L for Gram-positive S. aureus and 16 mg/L for Gram-negative E. coli .…”