10 research outputs found
Phenylpiperazine 5,5-dimethylhydantoin derivatives as first synthetic inhibitors of Msr(A) efflux pump in Staphylococcus epidermidis
Herein, 15 phenylpiperazine 3-benzyl-5,5-dimethylhydantoin derivatives (1–15) were screened for modulatory activity towards Msr(A) efflux pump present in S. epidermidis bacteria. Synthesis, crystallographic analysis, biological studies in vitro and structure–activity relationship (SAR) analysis were performed. The efflux pump inhibitory (EPI) potency was determined by employing ethidium bromide accumulation assay in both Msr(A) efflux pump overexpressed (K/14/1345) and deficient (ATCC 12228) S. epidermidis strains. The series of compounds was also evaluated for the capacity to reduce the resistance of K/14/1345 strain to erythromycin, a known substrate of Msr(A). The study identified five strong modulators for Msr(A) in S. epidermidis. The 2,4-dichlorobenzyl-hydantoin derivative 9 was found as the most potent EPI, inhibiting the efflux activity in K/14/1345 at a concentration as low as 15.63 µM. Crystallography-supported SAR analysis indicated structural properties that may be responsible for the activity found. This study identified the first synthetic compounds able to inhibit Msr(A) efflux pump transporter in S. epidermidis. Thus, the hydantoin-derived molecules found can be an attractive group in search for antibiotic adjuvants acting via Msr(A) transporter
Molecular Insights into an Antibiotic Enhancer Action of New Morpholine-Containing 5-Arylideneimidazolones in the Fight against MDR Bacteria
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
Molecular insights into an antibiotic enhancer action of new morpholine-containing 5-arylideneimidazolones in the fight against MDR bacteria
Analysis of the results of microbiology tests of patients with foot ulcer related to diabetic foot syndrome
Evaluation of the occurrence of genetic determinants of multi-drug resistance among Acinetobacter baumannii strains
Introduction: The aim of the study was the analysis of occurrence of genetic determinants of multi-drug resistance and the assessment of genetic relationship among Acinetobacter baumannii strains. Methods: Multiplex-PCR method was performed in order to: (1) confirm the phenotypic identification and (2) detect the presence of CHDL oxacillinases in the group of thirty A. baumannii strains. Further PCR studies included the analysis of the occurrence of genetic determinants associated with efflux pump, insertion sequence and biofilm formation. The relationship between bacterial strains was assayed using 6 primers in RAPD-PCR method. Results: Detection of the e gene confirmed that the strains belong to the A. baumannii species. In the multiplex-PCR, the presence of the and genes was detected in 3 (10%) and 27 (90%) isolates, respectively. Moreover, some strains showed the coexistence of the and genes (10%, n=3) or and e (90%, n=27). In the group of analysed strains the presence of the efflux pump gene (adeA) and the insertion sequence ISAba1 were demonstrated in all tested isolates. Biofilm-related genes (abaI, csuE) were found in 100% and 97% (n=29) tested strains adequately. The RAPD-PCR studies revealed the presence of 10 unrelated genotypes. Conclusions: The obtained results suggest that the phenomenon of multi-drug resistance in the studied A. baumannii strains could be attributed to the occurrence of CHDL oxacillinases, AdeABC efflux pump, insertion sequence ISAba1 and the biofilm formation
Molecular identification of strains within the Mycobacterium abscessus complex and determination of resistance to macrolides and aminoglycosides
Design and synthesis of novel arylurea derivatives of aryloxy(1-phenylpropyl) alicyclic diamines with antimicrobial activity against multidrug-resistant Gram-positive bacteria
Promising anticonvulsant and/or analgesic compounds among 5-chloro-2- or 5-chloro-4-methyl derivatives of xanthone coupled to aminoalkanol moieties - design, synthesis and pharmacological evaluation
molecules 5-Arylideneimidazolones with Amine at Position 3 as Potential Antibiotic Adjuvants against Multidrug Resistant Bacteria
International audienceSearching for new chemosensitizers of bacterial multidrug resistance (MDR), chemical modifications of (Z)-5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-4(5H)-one (6) were performed. New compounds (7-17), with fused aromatic rings at position 5, were designed and synthesized. Crystallographic X-ray analysis proved that the final compounds (7-17) were substituted with tertiary amine-propyl moiety at position 3 and primary amine group at 2 due to intramolecular Dimroth rearrangement. New compounds were evaluated on their antibiotic adjuvant properties in either Gram-positive or Gram-negative bacteria. Efflux pump inhibitor (EPI) properties towards the AcrAB-TolC pump in Enterobacter aerogenes (EA289) were investigated in the real-time efflux (RTE) assay. Docking and molecular dynamics were applied to estimate an interaction of compounds 6-17 with penicillin binding protein (PBP2a). In vitro ADME-Tox properties were evaluated for compound 9. Most of the tested compounds reduced significantly (4-32-fold) oxacillin MIC in highly resistant MRSA HEMSA 5 strain. The anthracene-morpholine derivative (16) was the most potent (32-fold reduction). The tested compounds displayed significant EPI properties during RTE assay (37-97%). The naphthyl-methylpiperazine derivative 9 showed the most potent "dual action" of both oxacillin adjuvant (MRSA) and EPI (E. aerogenes). Molecular modeling results suggested the allosteric mechanism of action of the imidazolones, which improved binding of oxacillin in the PBP2a active site in MRSA