Efflux Pump Inhibitor Phenylalanine-Arginine Β-Naphthylamide Effect on the Minimum Inhibitory Concentration of Imipenem in Acinetobacter baumannii Strains Isolated From Hospitalized Patients in Shahid Motahari Burn Hospital, Tehran, Iran

Carbapenem-resistant Acinetobacter baumannii (CRAB) Recovered from Burn Patients

“…The considerably high MICs for imipenem are of prime importance, as the imipenem or its comparators are the last-line antibiotics for the treatment of A. baumannii-associated infections. The MIC values of imipenem and ciprofloxacin against the isolates in this study was also similar to those previously reported (32)(33)(34)(35). These results indicate that the MIC values of tested antibiotics are high, thereby, indicating that most of CRAB might be also multidrug resistant.…”

Efflux pump expression in MDR Acinetobacter baumannii strains from a tertiary care hospital in Lima, Peru

“…Antimicrobial susceptibility to quinolones (levo oxacin, cipro oxacin) and aminoglycosides (tobramycin, amikacin) was assessed by broth microdilution technique, according to 2018 Clinical and Laboratory Standards Institute (CLSI) guidelines (28), and as described by Gholami et al (23), except nalidixic acid whose resistance values were assessed according to Clinical and Laboratory Standards Institute (CLSI) guidelines (29). MIC concentrations tested ranged from 0.25 µg/mL up to 256 µg/mL in a 96-well microtiter plate with 100 µL of the antibiotic dilution and Müller-Hinton broth.…”

“…The correct density of the samples was standardized at 625 nm spectrophotometry, and then were incubated at 37 °C for 24 hours. The MIC was the lowest concentration without detection of bacterial growth (23,28). Escherichia coli ATCC 25922 was used as a quality control strain.…”

“…The activity of the e ux pumps system was assessed by the addition of phenylalanine inhibitor of arginine-β-naphthylamide (PAβN) in broth microdilution, as previously assessed in the study of Gholami et al (23). E ux pump expression was based on a fourfold or greater reduction in the MIC as the criterion for signi cance as described in the literature (21,30).…”

“…Moreover, further research is needed to nd more suitable, new compounds and effective therapies (13) against A. baumannii. Updated available data particularly support the development of e ux pump inhibitors for use in combination with antibiotics (23). Further studies are required to assess the e cacy and safety of such compounds alongside current therapy in order to decrease the burden of disease attributable to this successful pathogen.…”