The MBEC™ Physiology & Genetics Assay recently became the first approved ASTM standardized biofilm disinfectant efficacy test method. This report summarizes the results of the standardization process using Pseudomonas aeruginosa biofilms. Initial ruggedness testing of the MBEC method suggests that the assay is rugged (i.e., insensitive) to small changes to the protocol with respect to 4 factors...

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...

BACKGROUND Quaternary ammonium compounds (QAC), which contain benzalkonium chloride as the most widely used agent, are employed as wound and skin antiseptics, as well as disinfectants in hospitals. The resistance mechanism to disinfectants is usually determine by genes which are related to resistance to quaternary ammonium compounds, namely, qacE, qacΔE1, qacΔE1 that are found in Gram-negative ...

The food-borne pathogen Listeria (L.) monocytogenes is often found in food production environments. Thus, controlling the occurrence of L. monocytogenes in food production is a great challenge for food safety. Among a great diversity of L. monocytogenes strains from food production, particularly strains belonging to sequence type (ST)121 are prevalent. The molecular reasons for the abundance of...

A new category of amphiphilic hydrolyzable quaternary ammonium compounds with rapid and high levels of antimicrobial activity was studied. The compounds, alkanoylcholines with hydrocarbon chains of 10 to 14 carbon atoms, are hydrolyzed by butyrylcholine esterase, which is present in human serum and mucosal membranes. The hydrolysis products are common components of human metabolism. Alkanoylcho...

Methicillin resistant Staphylococcus aureus (MRSA) and the means of controlling it, continue to be of major interest to the healthcare community. The bactericidal activity of some disinfectants which are in common use in seven major tertiary care hospitals in Riyadh was tested against two control strains of S. aureus, namely MRSA ATCC 33591 and Methicillin sensitive Staphylococcus aureus (MSSA)...

Leucothrix mucor Oersted, the primary cause of filamentous gill disease in cultured shrimp, was treated with algicides and surfactants by a serial dilution method. It was found to be highly sensitive to those algicides containing quaternary ammonium compounds. Copper-containing compounds and Formalin were less effective, whereas potassium permanganate and two surfactants, Dreft and Alconox, wer...

Ammonium Chlorochromate in Solventless System Majid M. Heravi* and Maryam M. Aghayan Chemistry and Chemical Engineering Research Center of Iran. P.O. Box 14335-186, Teheran, Iran. Fax: 0098(21) 8037185, E-mail: [email protected] Z. Naturforsch. 54b, 815Ð817 (1999); received December 2, 1998 Oxidation, Alcohols, Carbonyl Compounds, Wet Alumina, Solventless System, Ammonium Chlorochromate A simp...

some n¬-acyl-n'-aryl thiourea derivatives 4(a-f) have been prepared by the reaction of acyl halides ammonium thiocyanate and aryl amines. the structures of synthesized compounds have been characterized by ir, 1hnmr spectral studies. the synthesized compounds 5(a-f) have been screened for antibacterial activity. the effect of the structure of the investigated compounds on the antibacterial activ...

The synthesis of aluminosilicate zeolite, SSZ-25, is described using a two-component organic guest molecule strategy. This method has been recently described by us and is quite effective in crystallizing a variety of aluminosilicate zeolites with reduction in template cost. In this instance the original organic guest component used in the discovery of SSZ-25, N',N',N'-trimethyl-2-adamantammoniu...