Acinetobacter species are among the most life-threatening Gram-negative bacilli, causing hospital-acquired infections, and they are associated with high morbidity and mortality. They show multidrug resistance that acts via various mechanisms. In Acinetobacter baumannii, efflux pump-mediated resistance to many antimicrobial compounds, including tigecycline, has been widely reported. Natural compounds have been used for their various pharmacological properties, including anti-efflux pump activity. The present study aimed to evaluate the efflux pump-mediated resistance mechanism of Acinetobacter baumannii and the effect of (+)Usnic acid as an efflux pump inhibitor with tigecycline. For detecting the efflux pump activity of tigecycline-resistant Acinetobacter baumannii isolates, microbroth dilution method and real-time quantitative reverse transcription–polymerase chain reaction was used. (+)Usnic acid was added to tigecycline and tested by the checkerboard method to evaluate its efficacy as an efflux pump inhibitor. qRT-PCR analysis was carried out to show the downregulation of the efflux pump in the isolates. Out of 42 tigecycline-resistant Acinetobacter baumannii isolates, 19 showed efflux pump activity. All 19 strains expressed the adeB gene. (+)Usnic acid as an adjuvant showed better efficacy in lowering the minimum inhibitory concentration compared with the conventional efflux pump inhibitor, carbonyl cyanide phenylhydrazone.
Acinetobacter has already gained resistance to the majority of antibiotics available. Aminoglycosides are commonly used to treat invasive infections. Aminoglycoside resistance is associated with decreased drug absorption, aminoglycoside modification, and aminoglycoside efflux. The aim of this study was to detect the presence of an efflux mechanism in amikacin-resistant Acinetobacter isolated from hospital wards using Carbonyl Cyanide 3- Chlorophenylhydrazone (CCCP). One hundred isolates of Acinetobacter were isolated from tertiary care hospitals in two distinct South Indian states. Antibacterial susceptibility patterns were discovered between 2017 and 2019. Amikacin minimum inhibitory concentration (MIC) for resistant Acinetobacter isolates was determined using Clinical and Laboratory Standards Institute (CLSI) standards. The efflux system activity was determined using CCCP. Among 100 Acinetobacter baumannii isolates, 49 isolates with amikacin resistance were found. The MIC’s of Acinetobacter ranged between 2 – 1024 μg/mL for the amikacin studied. After treatment with the efflux pump inhibitor, 38.77% of isolates became less resistant to amikacin, as determined by phenotypic detection of efflux pumps, showing a decrease in antibiotic MICs of at least four fold. The data demonstrated the importance of efflux pump activity conferring amikacin resistance on Acinetobacter clinical isolates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.