scholarly journals Effect of Efflux Pump Inhibitor Carbonyl Cyanide 3-Chlorophenylhydrazone on the Minimum Inhibitory Concentration of Ciprofloxacin in Acinetobacter baumannii Clinical Isolates

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdollah Ardebili ◽  
Malihe Talebi ◽  
Leila Azimi ◽  
Abdolaziz Rastegar Lari
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Acinetobacter Baumannii ◽  
Inhibitory Concentration ◽  
Efflux Pump ◽  
Clinical Isolates ◽  
Efflux Pump Inhibitor ◽  
Carbonyl Cyanide

scholarly journals Screening antibiotics using an Hoechst 33342 dye-accumulation assay to detect efflux activity in Acinetobacter baumannii clinical isolates

2018 ◽  
Vol 11 (4) ◽  
pp. 371-378 ◽  
Author(s):  
In-Sun Choi ◽  
Choon-Mee Kim ◽  
Sook-Jin Jang
Keyword(s):  
Multidrug Resistance ◽  
Acinetobacter Baumannii ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Drug Efflux ◽  
Hoechst 33342 ◽  
Efflux Pump Inhibitor ◽  
Significant Difference

AbstractBackgroundUnderstanding the contribution of efflux pumps to the resistance of antibiotics is useful when considering strategies for antimicrobial therapy.ObjectivesTo assess the role of efflux activity on the resistance of antibiotics commonly used in hospitals.MethodsWe analyzed the efflux activity of 120 clinical isolates of Acinetobacter baumannii using an Hoechst 33342 (H33342) dye-accumulation assay. We compared the indicators for efflux activity of susceptible and non-susceptible groups of each of 16 tested antibiotics. To determine the role of efflux activity on resistance to an antibiotic, we used 3 criteria based on the results of the H33342-accumulation assay.ResultsThe evaluation suggests that efflux activity contributed to resistance to the following 11 antibiotics: cefepime, cefotaxime, ceftazidime, ciprofloxacin, gentamicin, imipenem, meropenem, piperacillin, piperacillin/tazobactam, ticarcillin/ clavulanic acid, and tigecycline. However, ampicillin/sulbactam, minocycline, and trimethoprim/sulfamethoxazole did not meet the criteria, suggesting resistance may not be mediated by efflux activity. A significant difference in efflux activity was observed between bacteria belonging to the multidrug-resistant Acinetobacter baumannii (MDRAB) group and those belonging to the non-MDRAB group.ConclusionsEfflux activity may contribute to multidrug resistance and particularly resistance to numerous antibiotics used in hospitals. These antibiotics would be good candidates for combination therapeutic regimens consisting of an antibiotic and an efflux pump inhibitor as an adjuvant to combat drug efflux.

scholarly journals Molecular Epidemiology and Mechanisms of Tigecycline Resistance in Clinical Isolates of Acinetobacter baumannii from a Chinese University Hospital

2013 ◽  
Vol 58 (1) ◽  
pp. 297-303 ◽  
Author(s):  
Mei Deng ◽  
Man-Hua Zhu ◽  
Jun-Jie Li ◽  
Sheng Bi ◽  
Zi-Ke Sheng ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Efflux Pump ◽  
Infectious Agent ◽  
Clinical Isolates ◽  
University Hospital ◽  
Resistance Pattern ◽  
Content Type ◽  
Active Efflux ◽  
Carbonyl Cyanide ◽  
Sequence Types

ABSTRACTBecause of its remarkable ability to acquire antibiotic resistance and to survive in nosocomial environments,Acinetobacter baumanniihas become a significant nosocomial infectious agent worldwide. Tigecycline is one of the few therapeutic options for treating infections caused byA. baumanniiisolates. However, tigecycline resistance has increasingly been reported. Our aim was to assess the prevalence and characteristics of efflux-based tigecycline resistance in clinical isolates ofA. baumanniicollected from a hospital in China. A total of 74A. baumanniiisolates, including 64 tigecycline-nonsusceptibleA. baumannii(TNAB) and 10 tigecycline-susceptibleA. baumannii(TSAB) isolates, were analyzed. The majority of them were determined to be positive foradeABC,adeRS,adeIJK, andabeM, while theadeEgene was found in only one TSAB isolate. Compared with the levels in TSAB isolates, the mean expression levels ofadeB,adeJ,adeG, andabeMin TNAB isolates were observed to increase 29-, 3-, 0.7-, and 1-fold, respectively. The efflux pump inhibitors (EPIs) phenyl-arginine-β-naphthylamide (PAβN) and carbonyl cyanide 3-chlorophenylhydrazone (CCCP) could partially reverse the resistance pattern of tigecycline. Moreover, thetetX1gene was detected in 12 (18.8%) TNAB isolates. To our knowledge, this is the first report of thetetX1gene being detected inA. baumanniiisolates. ST208 and ST191, which both clustered into clonal complex 92 (CC92), were the predominant sequence types (STs). This study showed that the active efflux pump AdeABC appeared to play important roles in the tigecycline resistance ofA. baumannii. The dissemination of TNAB isolates in our hospital is attributable mainly to the spread of CC92.

scholarly journals Curcumin as Efflux Pump Inhibitor Agent for Enhancement Treatment Against Multidrug Resistant Pseudomonas aeruginosa Isolates

2020 ◽  
pp. 59-67
Author(s):  
Sulaiman D. Sulaiman ◽  
Ghusoon A. Abdulhasan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Efflux Pump ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disc Diffusion Method ◽  
Efflux Pump Inhibitor ◽  
Before And After ◽  
Chromogenic Agar ◽  
Susceptibility Patterns

  Pseudomonas aeruginosa is considered as a developing opportunistic nosocomial pathogen and is well-known for its multidrug resistance that can be efficiently treated by a combination of antibiotics andefflux pump inhibitors (EPI). Therefore, the purpose of this study was to investigate the effect of curcumin as an EPI for the enhancement of the effectiveness of antibiotics against multidrug resistant (MDR) isolates ofP. aeruginosa. Susceptibility patterns of suspected bacteria was determined using the disc diffusion method andresistant bacteria were identified using chromogenic agar and 16S rDNA. The effectsof curcuminon the enhancement of antibiotics’s activity was evaluated usingthe broth microdilution method.The susceptibility patterns for 50 (67.6%) suspectedP. aeruginosaisolates showed that 36 (72%) of these isolateswere resistant to one of the used antibiotics,whereasonly 21 (42%) were MDR. The highest percentage of resistance was observedtoceftazidime (66%) followed by ciprofloxacin and levofloxacin (40%). Only 35 isolates were specified by chromogenic agar and 16S rDNAas P. aeruginosa.The minimal inhibitory concentration (MIC) of 35 isolates for ciprofloxacin resistant was between 4 and128 µg/ml while for ceftazidime was between 64and 512 µg/ml. After the addition of 50 μg/ml curcumin with ciprofloxacin, there wasa significant increase in the sensitivity (p≤ 0.01) of 13 MDR P.aeroginosa isolates whereas no differences in the sensitivity to ceftazidime were recorded before and after addition ofcurcumin. In conclusion, the results of this study show that curcumin can decrease the MIC value of ciprofloxacin in MDR isolates of P. aeruginosaand can be used as a native compound to enhance the treatment of resistant isolates with ciprofloxacin.

scholarly journals Assessment of Minocycline and Polymyxin B Combination against Acinetobacter baumannii

2015 ◽  
Vol 59 (5) ◽  
pp. 2720-2725 ◽  
Author(s):  
Dana R. Bowers ◽  
Henry Cao ◽  
Jian Zhou ◽  
Kimberly R. Ledesma ◽  
Dongxu Sun ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Clinical Utility ◽  
Efflux Pump ◽  
Polymyxin B ◽  
Intracellular Concentration ◽  
Bacterial Cells ◽  
Efflux Pump Inhibitor ◽  
Content Type

ABSTRACTAntimicrobial resistance amongAcinetobacter baumanniiis increasing worldwide, often necessitating combination therapy. The clinical utility of using minocycline with polymyxin B is not well established. In this study, we investigated the activity of minocycline and polymyxin B against 1 laboratory isolate and 3 clinical isolates ofA. baumannii. Minocycline susceptibility testing was performed with and without an efflux pump inhibitor, phenylalanine-arginine β-naphthylamide (PAβN). The intracellular minocycline concentration was determined with and without polymyxin B (0.5 μg/ml). Time-kill studies were performed over 24 h using approximately 106CFU/ml of each strain with clinically relevant minocycline concentrations (2 μg/ml and 8 μg/ml), with and without polymyxin B (0.5 μg/ml). Thein vivoefficacy of the combination was assessed in a neutropenic murine pneumonia model. Infected animals were administered minocycline (50 mg/kg), polymyxin B (10 mg/kg), or both to achieve clinically equivalent exposures in humans. A reduction in the minocycline MIC (≥4×) was observed in the presence of PAβN. The intracellular concentration andin vitrobactericidal effect of minocycline were both enhanced by polymyxin B. With 2 minocycline-susceptible strains, the bacterial burden in lung tissue at 24 h was considerably reduced by the combination compared to monotherapy with minocycline or polymyxin B. In addition, the combination prolonged survival of animals infected with a minocycline-susceptible strain. Polymyxin B increased the intracellular concentration of minocycline in bacterial cells and enhanced the bactericidal activity of minocycline, presumably due to efflux pump disruption. The clinical utility of this combination should be further investigated.

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