scholarly journals Antimicrobial Properties of the Polyaniline Composites against Pseudomonas aeruginosa and Klebsiella pneumoniae

2020 ◽  
Vol 11 (3) ◽  
pp. 59 ◽  
Author(s):  
Moorthy Maruthapandi ◽  
Arumugam Saravanan ◽  
John H. T. Luong ◽  
Aharon Gedanken
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Klebsiella Pneumoniae ◽  
Cell Walls ◽  
Antimicrobial Properties ◽  
Cell Lysis ◽  
Antimicrobial Activities ◽  
Sonochemical Method ◽  
Gram Negative ◽  
Polyaniline Composites

CuO, TiO2, or SiO2 was decorated on polyaniline (PANI) by a sonochemical method, and their antimicrobial properties were investigated for two common Gram-negative pathogens: Pseudomonas aeruginosa (PA) and Klebsiella pneumoniae (KP). Without PANI, CuO, TiO2, or SiO2 with a concentration of 220 µg/mL exhibited no antimicrobial activities. In contrast, PANI-CuO and PANI-TiO2 (1 mg/mL, each) completely suppressed the PA growth after 6 h of exposure, compared to 12 h for the PANI-SiO2 at the same concentration. The damage caused by PANI-SiO2 to KP was less effective, compared to that of PANI-TiO2 with the eradication time of 12 h versus 6 h, respectively. This bacterium was not affected by PANI-CuO. All the composites bind tightly to the negative groups of bacteria cell walls to compromise their regular activities, leading to the damage of the cell wall envelope and eventual cell lysis.

scholarly journals The extraction of cell walls of Pseudomonas aeruginosa with aqueous phenol. The insoluble residue and material from the aqueous layers

1967 ◽  
Vol 105 (2) ◽  
pp. 759-765 ◽  
Author(s):  
K. Clarke ◽  
G. W. Gray ◽  
D. A. Reaveley
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Cell Walls ◽  
Lipid A ◽  
Diaminopimelic Acid ◽  
Insoluble Residue ◽  
Muramic Acid ◽  
Gram Negative ◽  
Gram Negative Organisms ◽  
Residue Fraction

1. The insoluble residue and material present in the aqueous layers resulting from treatment of cell walls of Pseudomonas aeruginosa with aqueous phenol were examined. 2. The products (fractions AqI and AqII) isolated from the aqueous layers from the first and second extractions respectively account for approx. 25% and 12% of the cell wall and consist of both lipopolysaccharide and muropeptide. 3. The lipid part of the lipopolysaccharide is qualitatively similar to the corresponding material (lipid A) from other Gram-negative organisms, as is the polysaccharide part. 4. The insoluble residue (fraction R) contains sacculi, which also occur in fraction AqII. On hydrolysis, the sacculi yield glucosamine, muramic acid, alanine, glutamic acid and 2,6-diaminopimelic acid, together with small amounts of lysine, and they are therefore similar to the murein sacculi of other Gram-negative organisms. Fraction R also contains substantial amounts of protein, which differs from that obtained from the phenol layer. 5. The possible association or aggregation of lipopolysaccharide, murein and murein sacculi is discussed.

LYSOZYME SENSITIVITY OF THE CELL WALL OF PSEUDO-MONAS AERUGINOSA: FURTHER EVIDENCE FOR THE ROLE OF THE NON-PEPTIDOGLYCAN COMPONENTS IN CELL WALL RIGIDITY

1966 ◽  
Vol 12 (1) ◽  
pp. 105-108 ◽  
Author(s):  
K. Jane Carson ◽  
R. G. Eagon
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Electron Micrographs ◽  
Cell Walls ◽  
Gram Negative Bacteria ◽  
Normal Cells ◽  
Thin Sections ◽  
Gram Negative ◽  
Cell Wall Rigidity

Electron micrographs of thin sections of normal cells of Pseudomonas aeruginosa showed the cell walls to be convoluted and to be composed of two distinct layers. Electron micrographs of thin sections of lysozyme-treated cells of P. aeruginosa showed (a) that the cell walls lost much of their convoluted nature; (b) that the layers of the cell walls became diffuse and less distinct; and (c) that the cell walls became separated from the protoplasts over extensive cellular areas. These results suggest that the peptidoglycan component of the unaltered cell walls of P. aeruginosa is sensitive to lysozyme. Furthermore, it appears that the peptidoglycan component is not solely responsible for the rigidity of the cell walls of Gram-negative bacteria.

scholarly journals FINE STRUCTURE OF THE GRAM-NEGATIVE BACTERIUM ACETOBACTER SUBOXYDANS

1964 ◽  
Vol 20 (2) ◽  
pp. 217-233 ◽  
Author(s):  
G. W. Claus ◽  
L. E. Roth
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Walls ◽  
Negative Staining ◽  
Homogeneous Layer ◽  
Physical Treatment ◽  
Thin Sections ◽  
Gram Negative ◽  
Acetobacter Suboxydans ◽  
Negative Cell

The morphological features of the cell wall, plasma membrane, protoplasmic constituents, and flagella of Acetobacter suboxydans (ATCC 621) were studied by thin sectioning and negative staining. Thin sections of the cell wall demonstrate an outer membrane and an inner, more homogeneous layer. These observations are consistent with those of isolated, gram-negative cell-wall ghosts and the chemical analyses of gram-negative cell walls. Certain functional attributes of the cell-wall inner layer and the structural comparisons of gram-negative and gram-positive cell walls are considered. The plasma membrane is similar in appearance to the membrane of the cell wall and is occasionally found to be folded into the cytoplasm. Certain features of the protoplasm are described and discussed, including the diffuse states of the chromatinic material that appear to be correlated with the length of the cell and a polar differentiation in the area of expected flagellar attachment. Although the flagella appear hollow in thin sections, negative staining of isolated flagella does not substantiate this finding. Severe physical treatment occasionally produces a localized penetration into the central region of the flagellum, the diameter of which is much smaller then that expected from sections. A possible explanation of this apparent discrepancy is discussed.

scholarly journals In Vitro Anti-Helicobacter pyloriActivities of New Rifamycin Derivatives, KRM-1648 and KRM-1657

1999 ◽  
Vol 43 (5) ◽  
pp. 1072-1076 ◽  
Author(s):  
Junko K. Akada ◽  
Mutsunori Shirai ◽  
Kenji Fujii ◽  
Kiwamu Okita ◽  
Teruko Nakazawa
Keyword(s):  
Helicobacter Pylori ◽  
Cell Lysis ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bactericidal Activities ◽  
H Pylori ◽  
Time Kill

ABSTRACT The new rifamycin derivatives KRM-1657 and KRM-1648 were evaluated for their in vitro antimicrobial activities against 44 strains ofHelicobacter pylori. Although the drugs were not very active against other gram-negative bacteria, the MICs at which 90% of isolates are inhibited for these drugs were lower (0.002 and 0.008 μg/ml, respectively) than those of amoxicillin and rifampin forH. pylori. Time-kill studies revealed that the bactericidal activities of these agents were due to cell lysis. The results presented here indicate that these new rifamycin derivatives may be useful for the eradication of H. pylori infections.

scholarly journals National Surveillance of Antimicrobial Susceptibility of Bacteremic Gram-Negative Bacteria with Emphasis on Community-Acquired Resistant Isolates: Report from the 2019 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Po-Yu Liu ◽  
Yu-Lin Lee ◽  
Min-Chi Lu ◽  
Pei-Lan Shao ◽  
Po-Liang Lu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Gram Negative Bacteria ◽  
National Surveillance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

ABSTRACT A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored blaKPC (n = 17), blaOXA-48 (n = 2), and blaVIM (n = 1) genes.

The effects of phospholipid depletion on the cleavage pattern of the cell walls of frozen Gram-negative bacteria

1973 ◽  
Vol 19 (8) ◽  
pp. 1056-1057 ◽  
Author(s):  
A. Forge ◽  
J. W. Costerton
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Cytoplasmic Membrane ◽  
Gram Negative Bacteria ◽  
Cleavage Pattern ◽  
Gram Negative ◽  
Whole Cells ◽  
The Cross ◽  
Double Track ◽  
Chloroform Methanol

Extraction of whole cells of the marine pseudomonad (B-16) with chloroform–methanol causes the disappearance of the cleavage planes, and the cross-sectioned profile of both the cytoplasmic membrane and the double-track layer of the cell wall.

scholarly journals Susceptibility of Multiresistant Gram-Negative Bacteria to Fosfomycin and Performance of Different Susceptibility Testing Methods

2013 ◽  
Vol 58 (3) ◽  
pp. 1763-1767 ◽  
Author(s):  
L. V. Perdigão-Neto ◽  
M. S. Oliveira ◽  
C. F. Rizek ◽  
C. M. D. M. Carrilho ◽  
S. F. Costa ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Susceptibility Testing ◽  
Gram Negative Bacteria ◽  
Testing Methods ◽  
Gram Negative ◽  
Content Type ◽  
Agar Dilution ◽  
And Performance ◽  
Systemic Infections

ABSTRACTFosfomycin may be a treatment option for multiresistant Gram-negative bacteria. This study compared susceptibility methods using 94 multiresistant clinical isolates. With agar dilution (AD), susceptibilities were 81%, 7%, 96%, and 100% (CLSI) and 0%, 0%, 96%, and 30% (EUCAST), respectively, forAcinetobacter baumannii,Pseudomonas aeruginosa,Klebsiella pneumoniae, andEnterobacterspp. Categorical agreement between Etest and AD forEnterobacteriaceaeandA. baumanniiwas ≥80%. Disk diffusion was adequate only forEnterobacter. CLSI criteria for urine may be adequate for systemic infections.

scholarly journals Antimicrobial effect of essential oils of some Fijian medicinal plant leaves on pathogenic bacteria

2016 ◽  
Vol 34 (2) ◽  
pp. 35
Author(s):  
Prayna P. P. Maharaj ◽  
Riteshma Devi ◽  
Surendra Prasad
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agent ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
Antibacterial Properties ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative

Fiji is highly populated with plants containing essential oils (EO). The essential oils extracted from the leaves of the selected Fijian leafy plants were screened against two Gram-negative bacteria (Salmonella typhimurium, Pseudomonas aeruginosa) and three Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis). The agar diffusion method was used to examine the antimicrobial activities of the extracted EO. All the EO tested showed antibacterial properties against one or more strains while none of the EO was active against Pseudomonas aeruginosa. Viburnum lantana (Wayfaring tree), Annona muricata (Soursop), Coleus amboinicus (Spanish thyme) and Cinnamomum zeylancium (Cinnamon) showed good inhibition against both Gram-positive and Gram-negative bacteria and proved as worthy source of antimicrobial agent. These findings will help the Pacific population to use the studied plants leaves as antimicrobial agent.

scholarly journals Antimicrobial activity of soft and purified propolis extracts

Medicina ◽  
2008 ◽  
Vol 44 (12) ◽  
pp. 977 ◽  
Author(s):  
Alvydas Pavilonis ◽  
Algirdas Baranauskas ◽  
Ligita Puidokaitė ◽  
Žaneta Maželienė ◽  
Arūnas Savickas ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Phenolic Compounds ◽  
Klebsiella Pneumoniae ◽  
Gram Negative ◽  
Propolis Extract

Objective. To evaluate the antimicrobial activity of soft and purified propolis extracts. Study object and methods. Antimicrobial activity of soft and purified propolis extracts was determined with reference cultures of Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 33499, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 12459, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 8035, and fungus Candida albicans ATCC 60193. Microbiological tests were performed under aseptic conditions. Minimum inhibitory concentration (MIC) – the highest dilution of preparation (the lowest concentration of preparation) that suppresses growth of reference microorganisms – was determined. Results. Concentration of phenolic compounds in soft propolis extract that possesses antimicrobial activity against gram-positive (Staphylococcus aureus, Enterococcus faecalis) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis) is 0.587±0.054 mg and 0.587±0.054–0.394±0.022 mg (P>0.05) and in purified propolis extract – 0.427±0.044 mg and 0.256±0.02 mg (P>0.05). Klebsiella pneumoniae is most resistant to soft propolis extract when the concentration of phenolic compounds is 1.119± 0.152 mg and to purified propolis extract when the concentration of phenolic compounds is 1.013±0.189 mg (P>0.05). Spore-forming Bacillus subtilis bacteria are more sensitive to soft and purified propolis extracts when the concentration of phenolic compounds is 0.134±0.002 mg and 0.075±0.025 mg, respectively, and Bacillus cereus – when the concentration is 0.394±0.022 mg and 0.256±0.02 mg (P>0.05). Sensitivity of fungus Candida albicans to soft and purified propolis extracts is the same as Bacillus subtilis. Encapsulated bacterium Klebsiella pneumoniae is most resistant to antimicrobial action of soft and purified propolis extracts as compared with gram-positive Staphylococcus aureus and Enterococcus faecalis bacteria (P<0.05), gram-negative Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis (P<0.05), sporeforming Bacillus subtilis and Bacillus cereus bacteria (P<0.05), and fungus Candida albicans (P<0.05). There is no statistically significant difference between antimicrobial effect of soft propolis extract and purified propolis extract on gram-positive bacteria, gram-negative bacteria, spore-forming bacteria, encapsulated bacteria, and Candida fungus. Conclusions. Soft and purified propolis extracts possess antimicrobial activity. They could be recommended as natural preservatives in the manufacture of pharmaceutical products.

Antimicrobial Activity of New 2,4-Disubstituted Thiazolidinone Derivatives

2009 ◽  
Vol 64 (11-12) ◽  
pp. 785-789 ◽  
Author(s):  
Wael A. El-Sayed ◽  
Yasser K. Abdel-Monem ◽  
Nabil M. Yousif ◽  
Nashwa Tawfek ◽  
Mohamed T. Shaaban ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Antimicrobial Activities ◽  
Gram Positive ◽  
Streptomyces Species ◽  
Gram Negative

A number of new disubstituted 2,5-thiazolidinone derivatives were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). They displayed different degrees of antimicrobial activities or inhibitory actions

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