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PubMed1983

[The effect of new quaternary ammonium compounds on bacteria and fungi. 5: Synthesis of 3-methyl-n-alkylthiomethylpyridinium-, 1-methyl-3-n-alkylthiomethylimidazolium- and 1-ethyl-3-n-alkylthioimidazolinium chloride].

Synthesis of some chlorides indicated in headline and their antibacterial properties was described. Synthesis of quaternary pyridine and imidazoline chlorides was performed by reaction of chloromethyl-n-alkylthioether with 3-methylpyridine or 1-methyl- and 1-ethylimidazole. Antibacterial properties of obtained compounds was tested on 13 strains of bacteria and fungi. Chlorides with dodecyl radical indicated the best antibacterial activity.

Anti-Bacterial Agents↗
PubMed1975

Plasma concentrations and urinary excretion of the antiarrhythmic quaternary ammonium compound QX-572 in man.

A quantitative thin layer chromatographic (TLC) method has been developed for determination of the antiarrhythmic quaternary ammonium compound N,N-bis (phenylcarbamoyl methyl) dimethylammonium chloride (QX-572) in biological materials. Prior to chromatography QX-572 was transferred into chloroform as perchlorate by ion pair extraction. Tritium-labelled QX-572 was used as the internal standard and a TLC scanning spectrophotometer equipped with a linear detector system afforded the required accuracy, specificity and simplicity. The method was used to determine QX-572 in plasma from 11 patients with various cardiac diseases who received QX-572 8 mg/kg body wt. as an intravenous infusion over 30 min. There was a rapid initial decay of the plasma levels from 11.0+/-1.1 mug/ml (mean+/-SE) at the end of infusion to 3.5+/-0.5 mug/ml after 30 min. 240 min after commencement of the infusion the plasma level was 0.7+/-0.1 mug/ml. In these patients 22+/-2% (mean+/-SE) of the total administered dose of QX-572 was excreted unchanged in urine during the 24 hours following infusion of the drug. A second group of 28 patients with acute myocardial infarction also received QX-572 8 mg/kg body wt. Their plasma levels did not differ significantly from those found in the first group of patients. There was a poor correlation between the amount of QX-572 administered and plasma level at the end of the infusion. The study has provided some preliminary data about the pharmacokinetics of QX-572, but before a detailed analysis can be done data from longer periods of observation is required. The present results suggest that in future QX-572 can be administered in a standardized dosage, what would be advantageous in practice.

Adult↗
PubMed1979

Isolation and determination of quaternary ammonium compounds by means of XAD-columns and thin layer chromatography.

The potentials of XAD-columns for the isolation of quaternary ammonium compounds from aqueous media have been investigated. When adequate amounts of counter ions (perchlorate, chloride, phosphate, nitrate) were added to the aqueous sample, to the column pretreatment fluid and to the aqueous washing fluid, most quaternary compounds investigated were retained on the column and could be recovered by elution with methanol. Quantitation of decamethonium isolated in this way from urine samples could be performed on silicagel thin layer plates through visualization with iodine, followed by densitometric evaluation. Detection limits were 0.1 microgram/ml. Recoveries at the 1 microgram/ml level were between 80-90% with variation coefficients of less than 10%.

Chromatography↗
PubMed1984

Quantitation and purification of quaternary ammonium compounds from halophyte tissue.

A simple and sensitive spectrophotometric assay for quaternary ammonium compounds (QACs) based on Dragendorff's reagent is described. Although not specific for a particular QAC, the assay allows for rapid survey of tissue for QAC content. A separation method for QACs in halophyte tissue containing high levels of cations was developed using ion exchange resins and ninhydrin to remove the amino acid fraction.

Journal Article↗
PubMed2003

Novel plasmid-borne gene qacJ mediates resistance to quaternary ammonium compounds in equine Staphylococcus aureus, Staphylococcus simulans, and Staphylococcus intermedius.

We identified a novel plasmid-borne gene (designated qacJ) encoding resistance to quaternary ammonium compounds (QACs) in three staphylococcal species associated with chronic infections in four horses. qacJ was located on a 2,650-bp plasmid (designated pNVH01), a new member of the pC194 family of rolling-circle replication plasmids. The 107-amino-acid protein, QacJ, showed similarities to known proteins of the small multidrug resistance family: Smr/QacC (72.5%), QacG (82.6%), and QacH (73.4%). The benzalkonium chloride MIC for a qacJ-containing recombinant was higher than those for otherwise isogenic recombinants expressing Smr, QacG, or QacH. Molecular epidemiological analyses by pulsed-field gel electrophoresis suggested both the clonal spread of a qacJ-harboring Staphylococcus aureus strain and the horizontal transfer of pNVH01 within and between different equine staphylococcal species. The presence of pNVH01 of identical nucleotide sequence in different staphylococcal species suggests that recent transfer has occurred. In three of the horses, a skin preparation containing cetyltrimethylammonium bromide had been used extensively for several years; this might explain the selection of staphylococci harboring the novel QAC resistance gene.

Amino Acid Sequence↗
PubMed1999

Specific variations of fatty acid composition of Pseudomonas aeruginosa ATCC 15442 induced by quaternary ammonium compounds and relation with resistance to bactericidal activity.

The role of membrane fatty acid composition in the resistance of Pseudomonas aeruginosa ATCC 15442 to the bactericidal activity of Quaternary Ammonium Compounds (QACs) was investigated. The strain was grown in a medium with increasing concentrations of a QAC, benzyldimethyltetradecylammonium chloride (C14) and two non-QACs, sodium dichloroisocyanurate and tri-sodium phosphate. In the presence of C14 only, the strain was able to grow in concentrations higher than the minimal inhibitory concentration. As the strain adapted to C14, resistance to bactericidal activity of the same biocide increased. For the non-QACs, no change was noted when cells were grown in the presence of biocides. The C14-adapted cells showed variations in membrane fatty acid composition. A hierarchical clustering analysis was used to compare all fatty acid compositions of cultures in the presence, or not, of the three biocides used here and another QAC studied previously. The clusters obtained underlined specific variations of membrane fatty acids in response to the presence of QACs. Furthermore, with a simple linear regression analysis, a relationship was shown between the membrane fatty acids and the resistance developed by the strain against the bactericidal activity of C14.

Adaptation, Physiological↗
PubMed2002

Resistance to quaternary ammonium compounds in food-related bacteria.

Microbial resistance to antimicrobial agents continues to be a major problem. The frequent use and misuse of disinfectants based on quaternary ammonium compounds (QACs) in food-processing industries have imposed a selective pressure and may contribute to the emergence of disinfectant-resistant microorganisms. A total number of 1,325 Gram-negative isolates (Escherichia coli, other coliforms Vibrio spp., and Aeromonas spp.) and 500 Enterococcus spp. from food and food-processing industries and fish farming were screened for natural resistance to the QAC-based disinfectant benzalkonium chloride (BC). Of the 1,825 isolates, 16 strains, mainly from meat retail shops, showed low-level resistance to BC. None of the Enterococcus spp. from broiler, cattle, and pigs, the antibiotic-resistant E. coli from pig intestine and fish pathogens Vibrio spp. and Aeromonas spp. from the Norwegian fish farming industry were resistant to BC. The BC-resistant strains were examined for susceptibility to 15 different antibiotics, disinfectants, and dyes. No systematic cross-resistance between BC and any of the other antimicrobial agents tested was detected. Stable enhanced resistance in Enterobacter cloacae isolates was demonstrated by step-wise adaptation in increasing concentrations of BC. In conclusion, BC resistance among food-associated Gram-negative bacteria and Enterococcus spp. is not frequent, but resistance may develop to user concentrations after exposure to sublethal concentrations of BC.

Adaptation, Physiological↗
PubMedDate not supplied

[Regulation of the heat resistance of muscle fibers in Rana temporaria tadpoles by selecting the parental gametes using quaternary ammonium compounds and chelators].

In experiments on the frog Rana temporaria, studies have been made on the effect of selection of the parental sperm by quaternary ammonium compounds--tetraethylammonium and tetramethylammonium, as well as by chelating agents--EDTA and EGTA--on the heat resistance of muscle tissue in the progeny of the first generation. It was found that selection of the sperm for its maximum stability to the injurious (immobilizing) effect of these drugs affects quantitative relationship in the family between tadpoles with a high and low heat resistance of muscle fibers. Insemination of the eggs by the sperm with maximum stability to elimination by TEA and TMA favours the development of tadpoles with relatively low heat resistance of muscle fibers. On the contrary, sperm selection by EDTA and EDTA increases the amount of tadpoles with a higher heat resistance of muscles.

Animals↗
PubMed2000

Quaternary ammonium compound stresses induce specific variations in fatty acid composition of Pseudomonas aeruginosa.

The involvement of cell membrane fatty acids in resistance of Pseudomonas aeruginosa to Quaternary Ammonium Compounds (QACs) stresses was investigated. The strain was grown in a medium with increasing concentrations of different biocides: two QACs, and two non-QACs. In the presence of two QACs only, the strain was able to grow with increasing concentrations. During cellular adaptation to QACs, the resistance to the same biocide increased. A principal component analysis was performed with whole of fatty acid compositions which highlighted a specific variation for the cultures in presence of QACs. These modifications gave evidence of the outer membrane involvement in cellular response to the presence of QACs.

Fatty Acids↗
PubMed1977

[Photometric micro-determination of the residues of disinfectant quaternary ammonium compounds in milk. 3. Improvement and adaption for milk products (author's transl)].

The photometric method for the quantitative micro-determination of the residues of quaternary ammonium compounds (QAC) in milk was improved. The casein has proved as an essential interfering substance and it was largely eliminated. Furthermore the bond of QAC on casein in discussed. The minimum level für determination for QAC in milk was reduced to 0.2 ppm. By modifying the photometric method for some milk-products as cream, joghurt, and quarge QAC can be determined at minimal concentrations of 1 ppm.

Animals↗
PubMed2002

Kinetics of tethering quaternary ammonium compounds to K(+) channels.

Polymeric maleimido-quaternary ammonium (QA) compounds have been shown to function as molecular tape measures when covalently tethered to external cysteine residues of a Shaker K(+) channel (Blaustein R.O., P.A. Cole, C. Williams, and C. Miller. 2000. Nat. Struct. Biol. 7:309-311). For sufficiently long compounds, the cysteine-maleimide tethering reaction creates a high concentration, at the channel's pore, of a TEA-like moiety that irreversibly blocks current. This paper investigates a striking feature of the maleimide-cysteine tethering kinetics. Strong blockers-those that induce substantial levels (>80%) of irreversible inhibition of current-react with channel cysteines much more rapidly than weak blockers and, when delivered to channels with four cysteine targets, react with multiexponential kinetics. This behavior is shown to arise from the ability of a strong blocker to concentrate its maleimide end near a channel's cysteine target by exploiting the reversible pore-blocking affinity of its QA headgroup.

Animals↗
PubMed1986

Adaptation of aquatic microbial communities to quaternary ammonium compounds.

The effects of long-chain (C(12) to C(18)) quaternary ammonium compounds (QACs) on the density, heterotrophic activity, and biodegradation capabilities of heterotrophic bacteria were examined in situ in a lake ecosystem. Monoalkyl and dialkyl substituted QACs were tested over a range of concentrations (0.001 to 10 mg/liter) in both acute (3 h) and chronic (21 day) exposures. In general, none of the QACs tested had significant adverse effects on bacterial densities in either acute or chronic studies. However, significant decreases in bacterial heterotrophic activity were noted in acute studies at QAC concentrations from 0.1 to 10 mg/liter. Chronic exposure of lake microbial communities to a specific monoalkyl QAC resulted in an adaptive response and recovery of heterotrophic activity. No-observable-effect level in the adapted populations was >10 mg/liter. Chronic exposure also resulted in significant increases in the number and activity of bacteria capable of biodegrading the material. The increase in biodegradation capability was observed at low (microgram per liter) concentrations which are approximately the same as realistic environmental levels. In general, our studies indicated that exposure of lake microbial communities to QACs results in the development of adapted communities which are less sensitive to potential toxic effects and more active in the biodegradation of these materials.

Journal Article↗