scholarly journals Chlorin e6 mediated photodynamic inactivation for multidrug resistant Pseudomonas aeruginosa keratitis in mice in vivo

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Ming-Feng Wu ◽  
Mona Deichelbohrer ◽  
Thomas Tschernig ◽  
Matthias W. Laschke ◽  
Nóra Szentmáry ◽  
...  
2014 ◽  
Vol 20 (6) ◽  
pp. 343-349 ◽  
Author(s):  
Kazuki Tajima ◽  
Taku Miyake ◽  
Naohito Koike ◽  
Takaaki Hattori ◽  
Shigeto Kumakura ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mustafa Elhag ◽  
Ruaa Mohamed Alaagib ◽  
Nagla Mohamed Ahmed ◽  
Mustafa Abubaker ◽  
Esraa Musa Haroun ◽  
...  

Pseudomonas aeruginosa is a common pathogen that is responsible for serious hospital-acquired infections, ventilator-associated pneumonia, and various sepsis syndromes. Also, it is a multidrug-resistant pathogen recognized for its ubiquity and its intrinsically advanced antibiotic-resistant mechanisms. It usually affects immunocompromised individuals but can also infect immunocompetent individuals. There is no vaccine against it available till now. This study predicts an effective epitope-based vaccine against fructose bisphosphate aldolase (FBA) of Pseudomonas aeruginosa using immunoinformatics tools. The protein sequences were obtained from NCBI, and prediction tests were undertaken to analyze possible epitopes for B and T cells. Three B cell epitopes passed the antigenicity, accessibility, and hydrophilicity tests. Six MHC I epitopes were found to be promising, while four MHC II epitopes were found promising from the result set. Nineteen epitopes were shared between MHC I and II results. For the population coverage, the epitopes covered 95.62% worldwide excluding certain MHC II alleles. We recommend in vivo and in vitro studies to prove its effectiveness.


2020 ◽  
Vol 8 (2) ◽  
pp. 739-745 ◽  
Author(s):  
Weinan Jiang ◽  
Ximian Xiao ◽  
Yueming Wu ◽  
Weiwei Zhang ◽  
Zihao Cong ◽  
...  

Host defense peptide mimicking peptide polymer displayed potent in vitro and in vivo antimicrobial activity against clinically isolated multidrug resistant Pseudomonas aeruginosa.


1996 ◽  
Vol 40 (9) ◽  
pp. 2021-2028 ◽  
Author(s):  
K Poole ◽  
K Tetro ◽  
Q Zhao ◽  
S Neshat ◽  
D E Heinrichs ◽  
...  

The region upstream of the multiple antibiotic resistance efflux operon mexA-mexB-oprM in Pseudomonas aeruginosa was sequenced, and a gene, mexR, was identified. The predicted MexR product contains 147 amino acids with a molecular mass of 16,964 Da, which is consistent with the observed size of the overexpressed mexR gene product. MexR was homologous to MarR, the repressor of MarA-dependent multidrug resistance in Escherichia coli, and other repressors of the MarR family. A mexR knockout mutant showed a twofold increase in expression of both plasmid-borne and chromosomal mexA-reporter gene fusions compared with the MexR+ parent strain, indicating that the mexR gene product negatively regulates expression of the mexA-mexB-oprM operon. Furthermore, the cloned mexR gene product reduced expression of a plasmid-borne mexA-lacZ fusion in E. coli, indicating that MexR represses mexA-mexB-oprM expression directly. Consistent with the increased expression of the efflux operon in the mexR mutant, the mutant showed an increase (relative to its MexR+ parent) in resistance to several antimicrobial agents. Expression of a mexR-lacZ fusion increased threefold in a mexR knockout mutant, indicating that mexR is negatively autoregulated. OCR1, a nalB multidrug-resistant mutant which overproduces OprM, exhibited a greater than sevenfold increase in expression of a chromosomal mexA-phoA fusion compared with its parent. Introduction of a mexR knockout mutation in strain OCR1 eliminated this increase in efflux gene expression and, as expected, increased the susceptibility of the strain to a variety of antibiotics. The nucleotide sequences of the mexR genes of OCR1 and its parental strain revealed a single base substitution in the former which would cause a predicted substitution of Trp for Arg at position 69 of its mexR product. These data suggest that MexR possesses both repressor and activator function in vivo, the activator form being favored in nalB multidrug-resistant strains.


2009 ◽  
Vol 41 (5) ◽  
pp. 391-397 ◽  
Author(s):  
S.P. Tseng ◽  
L.J. Teng ◽  
C.T. Chen ◽  
T.H. Lo ◽  
W.C. Hung ◽  
...  

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Zhaojun Zheng ◽  
Nagendran Tharmalingam ◽  
Qingzhong Liu ◽  
Elamparithi Jayamani ◽  
Wooseong Kim ◽  
...  

ABSTRACT The increasing prevalence of antibiotic resistance has created an urgent need for alternative drugs with new mechanisms of action. Antimicrobial peptides (AMPs) are promising candidates that could address the spread of multidrug-resistant bacteria, either alone or in combination with conventional antibiotics. We studied the antimicrobial efficacy and bactericidal mechanism of cecropin A2, a 36-residue α-helical cationic peptide derived from Aedes aegypti cecropin A, focusing on the common pathogen Pseudomonas aeruginosa. The peptide showed little hemolytic activity and toxicity toward mammalian cells, and the MICs against most clinical P. aeruginosa isolates were 32 to 64 μg/ml, and its MICs versus other Gram-negative bacteria were 2 to 32 μg/ml. Importantly, cecropin A2 demonstrated synergistic activity against P. aeruginosa when combined with tetracycline, reducing the MICs of both agents by 8-fold. The combination was also effective in vivo in the P. aeruginosa/Galleria mellonella model (P < 0.001). We found that cecropin A2 bound to P. aeruginosa lipopolysaccharides, permeabilized the membrane, and interacted with the bacterial genomic DNA, thus facilitating the translocation of tetracycline into the cytoplasm. In summary, the combination of cecropin A2 and tetracycline demonstrated synergistic antibacterial activity against P. aeruginosa in vitro and in vivo, offering an alternative approach for the treatment of P. aeruginosa infections.


2020 ◽  
Author(s):  
Carolina Grande Perez ◽  
Evelyne Maillart ◽  
Véronique Yvette Miendje Deyi ◽  
Te Din Daniel Huang ◽  
Prochore Kamgang ◽  
...  

Abstract The non-fermenters, e.g. Pseudomonas aeruginosa, and the extended spectrum β-lactamases or carbapenemases producing enterobacteriaceae represent a serious threat for patients admitted in Intensive Care Units (ICUs). News antibiotics have been developed to treat multidrug resistant bacteria. However, treatment emerging resistance has been shown for many of these newest antibiotics. Cefiderocol, a siderophore-antibiotic, has been developed to overcome most of the resistance mechanisms and shows great efficacy against most multi-drug resistant and extensively drug resistant Gram-negative bacteria, including the non-fermenters. We report the case of a patient abundantly treated with antibiotics. He received 158 days of antibiotherapy on 230 hospitalization days, including a six-week course of cefiderocol, in 14 different treatment lines. The patient developed a Pseudomonas aeruginosa (MIC: 8 µg/ml, GES type ESBL) and a Citrobacter koseri (MIC: 16 µg/ml, CTX-M group 9 type class A β-lactamase and a class D OXA-1 oxacillinase) resistant to cefiderocol. This antibiotic should be used with caution to preserve its efficacy, within a strict antimicrobial stewardship program.


2018 ◽  
Vol 11 (2) ◽  
pp. 1105-1117 ◽  
Author(s):  
Shri Natrajan Arumugam ◽  
Akarsh Chickamagalur Rudraradhya ◽  
Sathish Sadagopan ◽  
Sunilkumar Sukumaran ◽  
Ganesh Sambasivam ◽  
...  

Pseudomonas aeruginosa is known to be a major cause of Hospital Acquired Infections leading to high mortality in immune-compromised patients. Due to precipitous rise in antibiotic resistance, bacteriophages are significant alternative therapeutic approach for treatment and to combat resistance development. Objective of the current study was to identify MDR Pseudomonas aeruginosa from clinical isolates and to isolate bacteriophages from sewage samples against these MDR Pseudomonas aeruginosa strains. One hundred and forty-four Pseudomonas isolates were tested for their susceptibility pattern with 13 different antibiotics by micro-broth dilution method. Frequency of multidrug resistant (MDR) and Extensive Drug resistant (XDR) of Pseudomonas aeruginosa were found to be 35.5% and 23.6%, respectively. 7.61% isolates were identified as Pan drug resistant (PDR). Rate of susceptibility pattern were Piperacillin/Tazobactam 75%, Polymyxin B 74.6%, Meropenem 73.6%, Colistin 69.2%, Cefepime 54.9%, Ciprofloxacin 54.2%, Gentamicin 54.2%, Aztreonam 53.5%, Tobramycin 47.9%, Ticarcillin/Clavulanic acid 46.9%, Ertapenem 45.8%, Ceftazidime 40.3% and Imipenem 39.2%. Ninety-four bacteriophages were isolated from sewage samples against Pseudomonas aeruginosa PAO1/ATCC9027/clinical strains and host range testing study was carried out with all MDR clinical isolates. Among 51 MDR strains 34 strains were infected by phages. Phage infectivity rate were calculated for individual phages based on their host range infectivity results. AP025 and AP006 phages exhibited good infectivity rate of 39% and 30% respectively against MDR strains. Combination of 5 phages (AP002, AP006, AP011, AP025 and AP067) lysed 62.7% of the strains. Based on the obtained results, phages could be employed for treatment of infections caused by MDR strains with substantiated in-vivo experiments.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 283 ◽  
Author(s):  
Jennifer Geddes-McAlister ◽  
Abirami Kugadas ◽  
Mihaela Gadjeva

Multidrug-resistant (MDR) bacterial infections are a leading cause of mortality, affecting approximately 250,000 people in Canada and over 2 million people in the United States, annually. The lack of efficacy of antibiotic-based treatments is often caused by inability of the drug to penetrate bacterial biofilms in sufficient concentrations, posing a major therapeutic challenge. Here, we review the most recent information about the architecture of Pseudomonas aeruginosa biofilms in vivo and describe how advances in imaging and mass spectroscopy analysis bring about novel therapeutic options and challenge existing dogmas.


2014 ◽  
Vol 63 (7) ◽  
pp. 945-955 ◽  
Author(s):  
Jessica Krezdorn ◽  
Sophie Adams ◽  
Peter J. Coote

The aim of this study was to compare the inhibitory effect of antibiotic combinations in vitro with efficacy in Galleria mellonella larvae in vivo to identify efficacious combinations that target Pseudomonas aeruginosa. P. aeruginosa NCTC 13437, a multidrug-resistant strain resistant to β-lactams and aminoglycosides, was used. Susceptibility to cefotaxime, piperacillin, meropenem, amikacin, levofloxacin and colistin alone, or in dual or triple combinations, was measured in vitro via a 24 h time-kill assay. In vitro results were then compared with the efficacy of the same dual or triple antibiotic combinations versus G. mellonella larvae infected with P. aeruginosa. G. mellonella haemolymph burden of P. aeruginosa was determined over 96 h post-infection and treatment with the most potent combination therapies. Many dual and triple combinations of antibiotics displayed synergistic inhibition of multidrug-resistant P. aeruginosa in vitro. There was little correlation between combinations that were synergistic in vitro and those that showed enhanced efficacy in vivo versus infected G. mellonella larvae. The most potent dual and triple combinations in vivo were cefotaxime plus piperacillin, and meropenem plus piperacillin and amikacin, respectively. Fewer combinations were found to offer enhanced therapeutic benefit in vivo compared with in vitro. The therapeutic benefit arising from treatment with antibiotic combinations in vivo correlated with reduced larval burden of P. aeruginosa. This study has identified antibiotic combinations that merit further investigation for their clinical potential and has demonstrated the utility of using G. mellonella to screen for novel antibiotic treatments that demonstrate efficacy in vivo.


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