A Strain of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound

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.

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A Strain of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound1

Journal of Milk and Food Technology ◽

10.4315/0022-2747-39.8.546 ◽

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.

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

Czech Journal of Food Sciences ◽

10.17221/528/2015-cjfs ◽

2016 ◽

Vol 34 (No. 3) ◽

pp. 204-210 ◽

Cited By ~ 5

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.

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Characterization of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound.

Biocontrol Science ◽

10.4265/bio.7.147 ◽

2002 ◽

Vol 7 (3) ◽

pp. 147-153 ◽

Cited By ~ 3

Author(s):

ATSUSHI TABATA ◽

TAKUYA MAEDA ◽

HIDEAKI NAGAMUNE ◽

HIROKI KOURAI

Keyword(s):

Pseudomonas Aeruginosa ◽

Quaternary Ammonium ◽

Quaternary Ammonium Compound ◽

Ammonium Compound

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

International Journal of Food Microbiology ◽

10.1016/s0168-1605(00)00189-6 ◽

2000 ◽

Vol 55 (1-3) ◽

pp. 157-159 ◽

Cited By ~ 26

Author(s):

L Guerin-Mechin ◽

F Dubois-Brissonnet ◽

B Heyd ◽

J.Y Leveau

Keyword(s):

Pseudomonas Aeruginosa ◽

Fatty Acid Composition ◽

Fatty Acid ◽

Acid Composition ◽

Quaternary Ammonium ◽

Quaternary Ammonium Compound ◽

Ammonium Compound

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A Strain of Pseudomonas aeruginosa Resistant to a Quaternary Ammonium Compound

Journal of Milk and Food Technology ◽

10.4315/0022-2747-39.2.101 ◽

1976 ◽

Vol 39 (2) ◽

pp. 101-106 ◽

Cited By ~ 7

Author(s):

C. J. WASHAM ◽

W. E. SANDINE ◽

P. R. ELLIKER

Keyword(s):

Pseudomonas Aeruginosa ◽

Cell Types ◽

Resistant Cell ◽

Ammonium Compound ◽

Biochemical Tests ◽

Prolonged Incubation ◽

Cell Extracts ◽

Permeability Studies ◽

Reduced Rate ◽

Resistant Cells

Pseudomonas aeruginosa cells were selected for their ability to grow in the presence of 770 ppm n-alkyl (50% C12, 30% C14, 17% C16, 3% C18) dimethyl dichlorobenzyl ammonium chloride (QAC). These cells retained resistance to the germicide throughout tri-weekly transfers for 7 months in tryptone glucose yeast extract broth containing no QAC. Comparisons of resistant and sensitive cells were made in an attempt to define the mechanism of resistance and to provide some information as to the mode of action of QAC. Broth cultures of the resistant strain displayed a distinct fruity odor. Gas chromatographic analysis showed that the QAC-resistant cells, unlike the sensitive, produced large quantities of ethyl acetate and ethyl valerate. Two bands of esterase activity were demonstrated in sensitive cell extracts by gel electrophoresis, while only one band was detected in the resistant cell extracts when alpha napthyl acetate was used as the substrate. Biochemical tests disclosed numerous differences between the two cell types, many of which appeared to be interrelated. The most significant differences were losses in the ability of resistant cells to synthesize extracellular lipase and protease enzymes. Many other biochemical tests on resistant cells were negative or became positive only after prolonged incubation. Resistant cells were also more resistant to osmotic disruption. Permeability studies indicated a reduced rate of glucose uptake by resistant cells. Furthermore, growth curve studies indicated a slower rate of growth by resistant cells and a 15-min longer generation time.

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

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2020/1470915 ◽

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.

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