Despite decades of therapeutic application of aminoglycosides, it is still a matter of debate if porins contribute to the translocation of the antibiotics across the bacterial outer membrane. Here, we quantified the uptake of kanamycin across the major porin channels OmpF and OmpC present in the outer membrane of . Our analysis revealed that, despite its relatively large size, about 10-20 kanamycin molecules per second permeate through OmpF and OmpC under a 10 μM concentration gradient, whereas OmpN does not allow the passage. Molecular simulations elucidate the uptake mechanism of kanamycin through these porins. Whole-cell studies with a defined set of porin mutants provide evidence that translocation of kanamycin via porins is relevant for antibiotic potency. The values are discussed with respect to other antibiotics.
Beta-lactam antibiotics are often the treatment of choice for serious bacterial infections. In a previous screen for novel genetic mediators affecting beta-lactam susceptibility, we discovered that deletion of , a conserved gene of unknown function, leads to increased resistance to beta-lactams, as well as increased susceptibility to detergent compounds. Here, we further characterize YdgH in , and using a combination of biochemical and cell biological approaches.
Unlabelled: Antibiotic resistance microorganisms (ARMs), particularly gram-negative bacteria, pose a global health threat. The effects of fermentation on phytochemicals are numerous, and exploring this potential is the focus of drug development. The study investigated the role of fermentation in modifying leaf secondary metabolites as an effective antibiotic against .
Background: There is a serious public health concern regarding the emergence of carbapenem-resistant Escherichia coli (CREC). The purpose of this study is to identify the molecular characterization and risk factors of CREC in Fujian province, China.
Methods: A total of 48 CREC isolates were collected from various clinical samples.
In Enterobacteriaceae, susceptibility to cephalosporins and carbapenems is often associated with membrane and enzymatic barrier resistance. For about 20 years, a large number of Klebsiella pneumoniae, Escherichia coli and Enterobacter cloacae presenting ß-lactam resistance have been isolated from medical clinics. In addition, some of the resistant isolates exhibited alterations in the outer membrane porin OmpC-OmpF orthologues, resulting in the complete absence of gene expression, replacement by another porin or mutations affecting channel properties.
Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Stockholm, Sweden; Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden.
This study was conducted to investigate decreased susceptibility (minimum inhibitory concentrations [MICs] 0.25-4 mg/L) and resistance (MICs > 4 mg/L) to aztreonam-avibactam (ATM-AVI). Contemporary non-replicate clinical isolates of carbapenemase-producing Escherichia coli (CP-EC) (n=90) and ESBL-producing E.
