Background: Increased expression of efflux pumps is an important mechanism of antibiotic resistance in Pseudomonas aeruginosa, and treatment with inhibitors of active efflux pumps seems an attractive strategy to combat with multidrug resistance. Assays using ethidium bromide (EtBr), which accumulates by binding to nucleic acids, are often employed to assess the efficacy of efflux pump inhibitors (EPIs). However, few studies have reported on assays using other nucleic acid dyes.
Objective: We used different classes of EPIs for MexAB- or MexXY-OprM to measure the accumulation of various fluorescent dyes, including SYBR Safe, AtlasSight, and GelGreen.
Methods: Escherichia coli MG1655ΔacrBΔtolC strain harboring plasmids carrying the mexAB-oprM (pABM) or mexXY-oprM (pXYM) genes of P. aeruginosa were constructed. Then, the accumulation of the above-mentioned nucleic acid dyes and EtBr was measured to assess the efflux ability in the presence and absence of EPIs (MexAB-OprM-specific inhibitor of pyridopyrimidine derivative [ABI-PP], berberine, non-specific inhibitor of phenylalanine-arginine β-naphthylamide [PAβN], and protonophore of carbonyl cyanide m-chlorophenyl hydrazone [CCCP]).
Results: Decreased accumulations of nucleic acid dyes were observed in strains with pABM or pXYM compared with the parental strain. ABI-PP or berberine addition significantly increased the accumulation of any nucleic acids in the strains with the specific pumps. PAβN or CCCP addition showed increased accumulation of almost all dye in strains with pABM or pXYM. However, the inhibition patterns of EPIs differed according to the nucleic acid dyes used.
Conclusions: Accumulation assays for EPIs were suitable to evaluate EPI candidates using various nucleic acid dyes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jiac.2022.01.003 | DOI Listing |
Langmuir
January 2025
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
The lateral flow assay is a strip-based analytical method for the portable and convenient detection of analytes of interest. It has the advantages of visual observation, autonomous sample flow, fast coloration time, minimal tedious operation procedures, and reliance on specialized instruments. However, the rough surface of the nitrocellulose membrane renders it difficult for the immobilized nucleic acids to remain in an ordered arrangement, and the immobilized nucleic acids are also liable to be digested in a complex matrix, inducing limited sensitivity and anti-interference.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Chemistry Department, University of Central Florida, Orlando, Florida 32816, USA.
Molecular beacon (MB) probes have been extensively used for nucleic acid analysis. However, MB probes fail to hybridize with folded DNA or RNA. Here, we demonstrate that MB probes equipped with extra sequences complementary to the analyte, named 'tail', can increase the signal-to-background ratio by ∼40-fold and hybridization rates by ∼800-fold compared to conventional MB probes.
View Article and Find Full Text PDFVirulence
December 2025
Henan International Joint Laboratory of Children's Infectious Diseases, Department of Neonatology, Henan Province Engineering Research Center of Diagnosis and Treatment of Pediatric Infection and Critical Care, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China.
is a gram-negative pathogen that can cause multiple diseases including sepsis, urinary tract infections, and pneumonia. The escalating detections of hypervirulent and antibiotic-resistant isolates are giving rise to growing public concerns. Outer membrane vesicles (OMVs) are spherical vesicles containing bioactive substances including lipopolysaccharides, peptidoglycans, periplasmic and cytoplasmic proteins, and nucleic acids.
View Article and Find Full Text PDFCells
December 2024
Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya 466-8550, Japan.
Alternative splicing is essential for the generation of various protein isoforms that are involved in cell differentiation and tissue development. In addition to internal coding exons, alternative splicing affects the exons with translation initiation codons; however, little is known about these exons. Here, we performed a systematic classification of human alternative exons using coding information.
View Article and Find Full Text PDFNucleic Acids Res
December 2024
Université de Strasbourg, Architecture et Réactivité de l'ARN, Institut de Biologie Moléculaire et Cellulaire du CNRS, 2 Allée Konrad Roentgen, 67084 Strasbourg, France.
The importance of Mg2+ ions for RNA structure and function cannot be overstated. Several attempts were made to establish a comprehensive Mg2+ binding site classification. However, such descriptions were hampered by poorly modelled ion binding sites as observed in a recent cryo-EM 1.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!