Faculty Opinions recommendation of Biased partitioning of the multidrug efflux pump AcrAB-TolC underlies long-lived phenotypic heterogeneity.

Author(s):  
Chris Whitfield
Science ◽  
2017 ◽  
Vol 356 (6335) ◽  
pp. 311-315 ◽  
Author(s):  
Tobias Bergmiller ◽  
Anna M. C. Andersson ◽  
Kathrin Tomasek ◽  
Enrique Balleza ◽  
Daniel J. Kiviet ◽  
...  

2021 ◽  
Vol 22 (4) ◽  
pp. 2062
Author(s):  
Aneta Kaczor ◽  
Karolina Witek ◽  
Sabina Podlewska ◽  
Veronique Sinou ◽  
Joanna Czekajewska ◽  
...  

In the search for an effective strategy to overcome antimicrobial resistance, a series of new morpholine-containing 5-arylideneimidazolones differing within either the amine moiety or at position five of imidazolones was explored as potential antibiotic adjuvants against Gram-positive and Gram-negative bacteria. Compounds (7–23) were tested for oxacillin adjuvant properties in the Methicillin-susceptible S. aureus (MSSA) strain ATCC 25923 and Methicillin-resistant S. aureus MRSA 19449. Compounds 14–16 were tested additionally in combination with various antibiotics. Molecular modelling was performed to assess potential mechanism of action. Microdilution and real-time efflux (RTE) assays were carried out in strains of K. aerogenes to determine the potential of compounds 7–23 to block the multidrug efflux pump AcrAB-TolC. Drug-like properties were determined experimentally. Two compounds (10, 15) containing non-condensed aromatic rings, significantly reduced oxacillin MICs in MRSA 19449, while 15 additionally enhanced the effectiveness of ampicillin. Results of molecular modelling confirmed the interaction with the allosteric site of PBP2a as a probable MDR-reversing mechanism. In RTE, the compounds inhibited AcrAB-TolC even to 90% (19). The 4-phenylbenzylidene derivative (15) demonstrated significant MDR-reversal “dual action” for β-lactam antibiotics in MRSA and inhibited AcrAB-TolC in K. aerogenes. 15 displayed also satisfied solubility and safety towards CYP3A4 in vitro.


Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 255
Author(s):  
Salma M. Abdelaziz ◽  
Khaled M. Aboshanab ◽  
Ibrahim S. Yahia ◽  
Mahmoud A. Yassien ◽  
Nadia A. Hassouna

In this study, the correlation between the antibiotic resistance genes and antibiotic susceptibility among the carbapenem-resistant Gram-negative pathogens (CRGNPs) recovered from patients diagnosed with acute pneumonia in Egypt was found. A total of 194 isolates including Klebsiella pneumoniae (89; 46%), Escherichia coli (47; 24%) and Pseudomonas aeruginosa (58; 30%) were recovered. Of these, 34 (18%) isolates were multiple drug resistant (MDR) and carbapenem resistant. For the K. pneumoniae MDR isolates (n = 22), blaNDM (14; 64%) was the most prevalent carbapenemase, followed by blaOXA-48 (11; 50%) and blaVIM (4; 18%). A significant association (p value < 0.05) was observed between the multidrug efflux pump (AcrA) and resistance to β-lactams and the aminoglycoside acetyl transferase gene (aac-6’-Ib) gene and resistance to ciprofloxacin, azithromycin and β-lactams (except for aztreonam). For P. aeruginosa, a significant association was noticed between the presence of the blaSHV gene and the multidrug efflux pump (MexA) and resistance to fluoroquinolones, amikacin, tobramycin, co-trimoxazole and β-lactams and between the aac-6’-Ib gene and resistance to aminoglycosides. All P. aeruginosa isolates (100%) harbored the MexAB-OprM multidrug efflux pump while 86% of the K. pneumoniae isolates harbored the AcrAB-TolC pump. Our results are of great medical importance for the guidance of healthcare practitioners for effective antibiotic prescription.


2001 ◽  
Vol 203 (2) ◽  
pp. 235-239 ◽  
Author(s):  
M.Nazmul Huda ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
Tomofusa Tsuchiya

2013 ◽  
Vol 135 (42) ◽  
pp. 15754-15762 ◽  
Author(s):  
Yean Sin Ong ◽  
Andrea Lakatos ◽  
Johanna Becker-Baldus ◽  
Klaas M. Pos ◽  
Clemens Glaubitz

2003 ◽  
Vol 47 (6) ◽  
pp. 419-427 ◽  
Author(s):  
Md. Nazmul Huda ◽  
Jing Chen ◽  
Yuji Morita ◽  
Teruo Kuroda ◽  
Tohru Mizushima ◽  
...  

2003 ◽  
Vol 47 (2) ◽  
pp. 665-669 ◽  
Author(s):  
Melissa A. Visalli ◽  
Ellen Murphy ◽  
Steven J. Projan ◽  
Patricia A. Bradford

ABSTRACT Tigecycline has good broad-spectrum activity against many gram-positive and gram-negative pathogens with the notable exception of the Proteeae. A study was performed to identify the mechanism responsible for the reduced susceptibility to tigecycline in Proteus mirabilis. Two independent transposon insertion mutants of P. mirabilis that had 16-fold-increased susceptibility to tigecycline were mapped to the acrB gene homolog of the Escherichia coli AcrRAB efflux system. Wild-type levels of decreased susceptibility to tigecycline were restored to the insertion mutants by complementation with a clone containing a PCR-derived fragment from the parental wild-type acrRAB efflux gene cluster. The AcrAB transport system appears to be associated with the intrinsic reduced susceptibility to tigecycline in P. mirabilis.


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