Antibacterial Activity of HR-756, Cefoxitin and Cefuroxime against Multiply Antibiotic-Resistant Strains of Enterobacteriaceae and Pseudomonas aeruginosa

Chemotherapy ◽  
1980 ◽  
Vol 26 (5) ◽  
pp. 334-343 ◽  
Author(s):  
Nicholas J. Legakis ◽  
Dimitris A. Kafetzis ◽  
Constantine J. Papadatos ◽  
John Th. Papavassiliou
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Antibiotic Resistant ◽  
Resistant Strains

Antibacterial Properties of Chinese Herbal Medicines against Nosocomial Antibiotic Resistant Strains of Pseudomonas aeruginosa in Taiwan

2007 ◽  
Vol 35 (06) ◽  
pp. 1047-1060 ◽  
Author(s):  
Ching-Shen Liu ◽  
Thau-Ming Cham ◽  
Cheng-Hong Yang ◽  
Hsueh-Wei Chang ◽  
Chia-Hong Chen ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Herbal Medicines ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Herbal Extracts ◽  
Chinese Herbal Medicines ◽  
Antibiotic Resistant ◽  
Chinese Herbal ◽  
Resistant Strains

Pseudomonas aeruginosa is well-recognized as a nosocomial pathogen, which exhibits inherent drug resistance. In this study, the antibacterial activity of ethanol extracts of 58 Chinese herbal medicines used in Taiwan were tested against 89 nosocomial antibiotic resistant strains of Pseudomonas aeruginosa. The results gathered by the disc diffusion method showed that 26 out of the 58 herbal extracts exhibited antibacterial activity. Among the 26 herbal extracts, 10 extracts showed broad-spectrum antibacterial activities and were selected for further antibacterial property assay. The minimum inhibitory concentrations (MIC) of the active partition fractions ranged from 0.25 to 11.0 mg/L. The presence of flavonoid compounds in the active fractions of test herbal extracts was observed by the TLC-bioautography. The results from the time-kill assay revealed that most of the herbal extracts completely killed the test organisms within 4 hours. Exposure of the test strains to a sub-MIC level of the herbal extracts for 10 consecutive subcultures did not induce resistance to the active components. A combination of the active herbal fractions with antibiotics showed that one of the herbal medicines, the hexane fraction of Ramulus Cinnamomi, possessed a synergistic effect with tetracycline, gentamycin, and streptomycin. In conclusion, the tested Chinese medical herbs have the potential to be developed into natural antibiotics. This is the first evaluation for screening large amounts of medical plants against nosocomial antibiotic resistant bacteria in Taiwan.

scholarly journals A Novel Cecropin D-Derived Short Cationic Antimicrobial Peptide Exhibits Antibacterial Activity Against Wild-Type and Multidrug-Resistant Strains of Klebsiella pneumoniae and Pseudomonas aeruginosa

2020 ◽  
Vol 16 ◽  
pp. 117693432093626
Author(s):  
Iván Darío Ocampo-Ibáñez ◽  
Yamil Liscano ◽  
Sandra Patricia Rivera-Sánchez ◽  
José Oñate-Garzón ◽  
Ashley Dayan Lugo-Guevara ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Health Concern ◽  
Wild Type ◽  
Cationic Antimicrobial Peptide ◽  
Promising Alternative ◽  
Resistant Strains

Infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa and Klebsiella pneumoniae are a serious worldwide public health concern due to the ineffectiveness of empirical antibiotic therapy. Therefore, research and the development of new antibiotic alternatives are urgently needed to control these bacteria. The use of cationic antimicrobial peptides (CAMPs) is a promising candidate alternative therapeutic strategy to antibiotics because they exhibit antibacterial activity against both antibiotic susceptible and MDR strains. In this study, we aimed to investigate the in vitro antibacterial effect of a short synthetic CAMP derived from the ΔM2 analog of Cec D-like (CAMP-CecD) against clinical isolates of K pneumoniae (n = 30) and P aeruginosa (n = 30), as well as its hemolytic activity. Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of CAMP-CecD against wild-type and MDR strains were determined by the broth microdilution test. In addition, an in silico molecular dynamic simulation was performed to predict the interaction between CAMP-CecD and membrane models of K pneumoniae and P aeruginosa. The results revealed a bactericidal effect of CAMP-CecD against both wild-type and resistant strains, but MDR P aeruginosa showed higher susceptibility to this peptide with MIC values between 32 and >256 μg/mL. CAMP-CecD showed higher stability in the P aeruginosa membrane model compared with the K pneumoniae model due to the greater number of noncovalent interactions with phospholipid 1-Palmitoyl-2-oleyl-sn-glycero-3-(phospho-rac-(1-glycerol)) (POPG). This may be related to the boosted effectiveness of the peptide against P aeruginosa clinical isolates. Given the antibacterial activity of CAMP-CecD against wild-type and MDR clinical isolates of P aeruginosa and K pneumoniae and its nonhemolytic effects on human erythrocytes, CAMP-CecD may be a promising alternative to conventional antibiotics.

scholarly journals The Response of Pseudomonas aeruginosa PAO1 to UV-activated Titanium Dioxide/Silica Nanotubes

2020 ◽  
Vol 21 (20) ◽  
pp. 7748
Author(s):  
Adrian Augustyniak ◽  
Krzysztof Cendrowski ◽  
Bartłomiej Grygorcewicz ◽  
Joanna Jabłońska ◽  
Paweł Nawrotek ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Titanium Dioxide ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Uv Light ◽  
Alternative Methods ◽  
Silica Nanotubes ◽  
Antibiotic Resistant ◽  
Metabolic Functions ◽  
Resistant Strains

Pseudomonas aeruginosa is a bacterium of high clinical and biotechnological importance thanks to its high adaptability to environmental conditions. The increasing incidence of antibiotic-resistant strains has created a need for alternative methods to increase the chance of recovery in infected patients. Various nanomaterials have the potential to be used for this purpose. Therefore, we aimed to study the physiological response of P. aeruginosa PAO1 to titanium dioxide/silica nanotubes. The results suggest that UV light-irradiated nanomaterial triggers strong agglomeration in the studied bacteria that was confirmed by microscopy, spectrophotometry, and flow cytometry. The effect was diminished when the nanomaterial was applied without initial irradiation, with UV light indicating that the creation of reactive oxygen species could play a role in this phenomenon. The nanocomposite also affected biofilm formation ability. Even though the biomass of biofilms was comparable, the viability of cells in biofilms was upregulated in 48-hour biofilms. Furthermore, from six selected genes, the mexA coding efflux pump was upregulated, which could be associated with an interaction with TiO2. The results show that titanium dioxide/silica nanotubes may alter the physiological and metabolic functions of P. aeruginosa PAO1.

scholarly journals The study of antibacterial activity of some plant extracts against causes of pneumonia

2011 ◽  
Vol 8 (2) ◽  
pp. 248-254
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Penicillin G ◽  
Cydonia Oblonga ◽  
Resistance To Penicillin ◽  
Resistant Strains ◽  
Inhibition Zones ◽  
Antibiotics Sensitivity ◽  
Eucalyptus Microtheca

Eighty five samples were taken from patients suffering from pneumonia. Seventy-eight isolates were diagnosed as following: Staphylococcus aureus (23), klebsiella pneumoniae (29), Streptococcus pneumoniae (15), Serratia sp. (4), Haemophilus influenzae (4) and Pseudomonas aeruginosa (3). The clinical isolates were tested for antibiotics sensitivity. They appeared highly resistance to penicillin G and Ampicillin at percentage 89.7 and 84.6% respectly while the results showed highly sensitivity to streptomycin at percentege of (12.8%). To study the antibacterial activity of Alium sativum, Eucalyptus microtheca leaves and Cydonia oblonga seeds extracts, five multi resistant strains were used by using agar well diffusion and disk methods at concentrations of (24, 12, 6, 3)%. The agar well diffusion was prefered for both of Alium sativum and Eucalyptus microthesca extracts while both methods were prefered for Cydonia oblonga extract by measuring inhibition zones .The results showed antibacterial activity of Alium sativum on S.aureus and S. pneumoniae at concentration 3-24 % and for klebsiella pneumoniae at concentration of 6-24%While it was 12-24%for Serratia sp. and Pseudomonas aeruginosa. Eucalyptus microtheca extracts showed antibacterial at concentration of 24-3%for S.aureus, S. pneumoniae and Ps. aeruginosa. While K. pneumoniae and Serratia sp sensitive at concartatins of 24%. The ethanol and oil extracts of Cydonia oblonga seeds had anti bacterial activity at all concentrations for all strains except Serratia sp. showed sensitivity at concentrations of 24-6%for both extracts.

scholarly journals Mechanism of Enhanced Activity of Liposome-Entrapped Aminoglycosides against Resistant Strains of Pseudomonas aeruginosa

2006 ◽  
Vol 50 (6) ◽  
pp. 2016-2022 ◽  
Author(s):  
Clement Mugabe ◽  
Majed Halwani ◽  
Ali O. Azghani ◽  
Robert M. Lafrenie ◽  
Abdelwahab Omri
Keyword(s):  
Flow Cytometry ◽  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Fusion Rate ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Transmission Electron ◽  
Resistant Strains ◽  
Conventional Antibiotics ◽  
Liposomal Drugs

ABSTRACT Pseudomonas aeruginosa is inherently resistant to most conventional antibiotics. The mechanism of resistance of this bacterium is mainly associated with the low permeability of its outer membrane to these agents. We sought to assess the bactericidal efficacy of liposome-entrapped aminoglycosides against resistant clinical strains of P. aeruginosa and to define the mechanism of liposome-bacterium interactions. Aminoglycosides were incorporated into liposomes, and the bactericidal efficacies of both free and liposomal drugs were evaluated. To define the mechanism of liposome-bacterium interactions, transmission electron microscopy (TEM), flow cytometry, lipid mixing assay, and immunocytochemistry were employed. Encapsulation of aminoglycosides into liposomes significantly increased their antibacterial activity against the resistant strains used in this study (MICs of ≥32 versus ≤8 μg/ml). TEM observations showed that liposomes interact intimately with the outer membrane of P. aeruginosa, leading to the membrane deformation. The flow cytometry and lipid mixing assays confirmed liposome-bacterial membrane fusion, which increased as a function of incubation time. The maximum fusion rate was 54.3% ± 1.5% for an antibiotic-sensitive strain of P. aeruginosa and 57.8% ± 1.9% for a drug-resistant strain. The fusion between liposomes and P. aeruginosa significantly enhanced the antibiotics' penetration into the bacterial cells (3.2 ± 2.3 versus 24.2 ± 6.2 gold particles/bacterium, P ≤ 0.001). Our data suggest that liposome-entrapped antibiotics could successfully resolve infections caused by antibiotic-resistant P. aeruginosa through an enhanced mechanism of drug entry into the bacterial cells.

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