scholarly journals  Biofilm formation by Pseudomonas aeruginosa and disinfectant susceptibility of planktonic and biofilm cells

2016 ◽  
Vol 34 (No. 3) ◽  
pp. 204-210 ◽  
Author(s):  
Olszewska Magdalena A ◽  
Kocot Aleksandra M ◽  
Stanowicka Aleksandra ◽  
Łaniewska-Trokenheim Łucja
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quaternary Ammonium ◽  
Biofilm Formation ◽  
Membrane Integrity ◽  
Quaternary Ammonium Compound ◽  
Epifluorescence Microscopy ◽  
Ammonium Compound ◽  
Cell Membrane Integrity ◽  
Propidium Iodide Staining ◽  
Chamber Slide

Epifluorescence microscopy (EFM) was used to study the biofilm formation of Pseudomonas aeruginosa after 6, 24, 30, 48, 54, 72, 78, and 96 h growth in a chamber slide system. For this purpose, the biofilm was stained with the Live/Dead BacLight, wherein live and dead cells were visualised based on the cell membrane integrity. With the use of EFM we described 8- of 9-stage biofilm characteristics after 78 h of growth, since the majority of microscopic fields were fully covered with attached cells. However, the 96-h growth resulted in the cell detachment and revealed 30% of dead cells of all those cells that remained on the surface. The susceptibility testing of planktonic and biofilm cells to two disinfectants, chlorine-based and quaternary ammonium compound-based, revealed that biofilm cells were more tolerant to a chlorine-based sanitiser than planktonic counterparts. P. aeruginosa was inhibited by lower concentrations of the quaternary ammonium compound-based sanitiser than the chlorine-based sanitiser, which on the other hand was more effective in cell inactivation, as both the MIC/MBC (inhibitory/bactericidal) measurement and the CFDA/PI (carboxyfluorescein diacetate/propidium iodide) staining indicated.

A Strain of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound1

1976 ◽  
Vol 39 (8) ◽  
pp. 546-550
Author(s):  
C. J. WASHAM ◽  
W. E. SANDINE ◽  
P. R. ELLIKER
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quaternary Ammonium ◽  
Inclusion Bodies ◽  
Light And Electron Microscopy ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
Dense Inclusion ◽  
Yeast Extract Agar ◽  
Electron Dense Inclusion ◽  
Resistant Cells

Light and electron microscopy studies were made of Pseudomonas aeruginosa strains which were sensitive and resistant to a quaternary ammonium compound (QAC). The colonies of the sensitive cells on Tryptone Glucose Yeast Extract Agar were granular and homogeneous in consistency. In contrast, the colonies of the resistant strain on the same medium were granular, non-homogenous, and contained numerous dense areas. Morphological observations revealed the resistant cells to be 30% smaller than sensitive cells and non-motile due to loss of polar flagella, a characteristic which was not restored when the organisms were cultured in the absence of QAC for more than 7 months. Electron-dense inclusion bodies were present in resistant cells; they ranged in size from about 0.05 to 0.2 μm in diameter. These bodies, which were not identified, were released intact from lysing cells; as many as 20 per cell were visible.

scholarly journals Spatial and Temporal Patterns of Biocide Action against Staphylococcus epidermidis Biofilms

2010 ◽  
Vol 54 (7) ◽  
pp. 2920-2927 ◽  
Author(s):  
William M. Davison ◽  
Betsey Pitts ◽  
Philip S. Stewart
Keyword(s):  
Quaternary Ammonium ◽  
Staphylococcus Epidermidis ◽  
Membrane Integrity ◽  
Temporal Patterns ◽  
Quaternary Ammonium Compound ◽  
Antimicrobial Action ◽  
Ammonium Compound ◽  
Spatial And Temporal Patterns ◽  
Cell Clusters ◽  
Biofilm Removal

ABSTRACT The dynamic antimicrobial action of chlorine, a quaternary ammonium compound, glutaraldehyde, and nisin within biofilm cell clusters of Staphylococcus epidermidis was investigated using time-lapse confocal scanning laser microscopy. The technique allowed for the simultaneous imaging of changes in biofilm structure and disruption of cellular membrane integrity through the loss of an unbound fluorophore loaded into bacterial cells prior to antimicrobial challenge. Each of the four antimicrobial agents produced distinct spatial and temporal patterns of fluorescence loss. The antimicrobial action of chlorine was localized around the periphery of biofilm cell clusters. Chlorine was the only antimicrobial agent that caused any biofilm removal. Treatment with the quaternary ammonium compound caused membrane permeabilization that started at the periphery of cell clusters, then migrated steadily inward. A secondary pattern superimposed on the penetration dynamic suggested a subpopulation of less-susceptible cells. These bacteria lost fluorescence much more slowly than the majority of the population. Nisin caused a rapid and uniform loss of green fluorescence from all parts of the biofilm without any removal of biofilm. Glutaraldehyde caused no biofilm removal and also no loss of membrane integrity. Measurements of biocide penetration and action time at the center of cell clusters yielded 46 min for 10 mg liter−1 chlorine, 21 min for 50 mg liter−1 chlorine, 25 min for the quaternary ammonium compound, and 4 min for nisin. These results underscore the distinction between biofilm removal and killing and reinforce the critical role of biocide reactivity in determining the rate of biofilm penetration.

Characterization of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound.

2002 ◽  
Vol 7 (3) ◽  
pp. 147-153 ◽  
Author(s):  
ATSUSHI TABATA ◽  
TAKUYA MAEDA ◽  
HIDEAKI NAGAMUNE ◽  
HIROKI KOURAI
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound

A Strain of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound

1976 ◽  
Vol 39 (4) ◽  
pp. 273-279 ◽  
Author(s):  
C. J. WASHAM ◽  
W. E. SANDINE ◽  
P. R. ELLIKER
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Yeast Extract ◽  
Quaternary Ammonium ◽  
Cell Types ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
Ph Range ◽  
Second Peak ◽  
Precise Degree ◽  
Resistant Cells

Cells of Pseudomonas aeruginosa able to grow in Tryptone glucose yeast extract (TGY) broth containing 750 μg/ml of quaternary ammonium compound (alkyldimethylethylbenzyl ammonium chloride-(QAC) were studied in comparison to sensitive cells unable to grow in such medium to identify factors important in determining the precise degree of resistance. The germicidal activity of QAC solutions against both sensitive and resistant cells in TGY broth was shown to be greatly affected by the concentration of Tryptone and yeast extract, but not by the amount of sugar. The pH of the broth also influenced germicidal activity; both strains were more susceptible under slightly acid conditions. A comparison of the pH range of growth of sensitive and resistant cells demonstrated the abiility of the former to grow in TGY broth at pH 4.5 while the latter could not achieve growth at pH 5.0. A study of the effects of 50 ppm QAC, buffered to various pH values, indicated that susceptibility of resistant cells was nearly the same as that of sensitive cells below pH 3.0, at pH 6.0, and above pH 9.0. The greatest difference between the two cell types occurred from pH 3.5 to pH 4.5 with a second peak of resistance being observed from pH 7.0 to pH 8.5.

scholarly journals Prevalence and Detection of qac Genes from Disinfectant-Resistant Staphylococcus aureus Isolated from Salon Tools in Ishaka Town, Bushenyi District of Uganda

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Solange Gahongayire ◽  
Adamu Almustapha Aliero ◽  
Charles Drago Kato ◽  
Alice Namatovu
Keyword(s):  
Sodium Hypochlorite ◽  
Quaternary Ammonium ◽  
Bacterial Infections ◽  
Healthcare Providers ◽  
Quaternary Ammonium Compound ◽  
Diffusion Method ◽  
Ammonium Compound ◽  
Bacterial Strains ◽  
Microbiological Methods ◽  
Phenotypic Methods

Bacterial infections are on a rise with causal-resistant strains increasing the economic burden to both patients and healthcare providers. Salons are recently reported as one of the sources for transmission of such resistant bacterial strains. The current study aimed at the identification of the prevalent bacteria and characterization of quaternary ammonium compound (qac) genes from disinfectant-resistant S. aureus isolated from salon tools in Ishaka town, Bushenyi District of Uganda. A total of 125 swabs were collected from different salon tools (combs, brushes, scissors, clippers, and shaving machines), and prevalent bacteria were isolated using standard microbiological methods. Identification of isolated bacteria was done using standard phenotypic methods including analytical profile index (API). Susceptibility patterns of the isolated bacteria to disinfectant were determined using the agar well diffusion method. Quaternary ammonium compound (qac) genes (qacA/B and qacC) associated with disinfectant resistances were detected from disinfectant-resistant S. aureus using multiplex polymerase chain reaction (PCR) and Sanger sequencing methods. Of the 125 swab samples collected from salons, 78 (62.4%) were contaminated with different bacteria species. Among the salon tools, clippers had the highest contamination of 20 (80.0%), while shaving machines had the lowest contamination of 11 (44.0%). The most prevalent bacteria identified were Staphylococcus epidermidis (28.1%) followed by S. aureus (26.5%). Of all the disinfectants tested, the highest resistance was shown with sodium hypochlorite 1%. Out of the eight (8) disinfectant-resistant S. aureus analysed for qac genes, 2 (25%) isolates (STP6 and STP9) were found to be qacA/B positive, while 2 (25%) isolates (STP8 and STP9) were found to be qacC gene positive. This study has shown that bacterial contamination of salon tools is common, coupled with resistance to disinfectants with sodium hypochlorite resistance being more common. Furthermore, observed resistance was attributed to the presence of qac genes among S. aureus isolates. A search for qac genes for disinfectant resistance from other bacteria species is recommended.

Building a Better Quaternary Ammonium Compound (QAC): Branched Tetracationic Antiseptic Amphiphiles

ChemMedChem ◽  
2016 ◽  
Vol 11 (13) ◽  
pp. 1401-1405 ◽  
Author(s):  
Megan E. Forman ◽  
Megan C. Jennings ◽  
William M. Wuest ◽  
Kevin P. C. Minbiole
Keyword(s):  
Quaternary Ammonium ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound
Sign in / Sign up

Export Citation Format

Share Document