Acinetobacter baumannii
SusceptibilityIn Vitro Activity of Cefiderocol, a Siderophore Cephalosporin, against Multidrug-Resistant Gram-Negative BacteriaCefiderocol is a parenteral siderophore cephalosporin with a catechol-containing 3′ substituent. We evaluated its MICs against Gram-negative bacteria, using iron-depleted Mueller-Hinton broth. The panel comprised 305 isolates of Enterobacterales, 111 of Pseudomonas aeruginosa, and 99 of ...
Mechanisms of ResistanceStructural Insights into Inhibition of the Acinetobacter-Derived Cephalosporinase ADC-7 by Ceftazidime and Its Boronic Acid Transition State AnalogExtended-spectrum class C β-lactamases have evolved to rapidly inactivate expanded-spectrum cephalosporins, a class of antibiotics designed to be resistant to hydrolysis by β-lactamase enzymes. To better understand the mechanism by which Acinetobacter-derived cephalosporinase-...
PharmacologyActivities of Cefiderocol with Simulated Human Plasma Concentrations against Carbapenem-Resistant Gram-Negative Bacilli in an In Vitro Chemostat ModelActivities of cefiderocol under simulated human plasma concentrations at the recommended dosing regimen of 2 g every 8 h with a 3-h infusion were evaluated using an in vitro chemostat model. Against a total of 6 meropenem-resistant Gram-negative strains with cefiderocol MICs of 0.5 to 4 μg/ml, including metallo-β-lactamase producers and carbapenem-resistant ...
Editor's Pick Epidemiology and SurveillanceA Diverse Panel of Clinical Acinetobacter baumannii for Research and DevelopmentOver the past two decades, Acinetobacter baumannii has emerged as a leading cause of nosocomial infections worldwide. Of particular concern are panresistant strains, leading the World Health Organization (WHO) to designate carbapenem-resistant A. baumannii as a priority 1 (critical) pathogen for...
Mechanisms of ResistanceScarless Removal of Large Resistance Island AbaR Results in Antibiotic Susceptibility and Increased Natural Transformability in Acinetobacter baumanniiWith a great diversity in gene composition, including multiple putative antibiotic resistance genes, AbaR islands are potential contributors to multidrug resistance in Acinetobacter baumannii. However, the effective contribution of AbaR to antibiotic resistance and bacterial physiology remains elusive. To address this, we sought to accurately remove AbaR islands and...
Editor's Pick Experimental TherapeuticsPreserving Vascular Integrity Protects Mice against Multidrug-Resistant Gram-Negative Bacterial InfectionThe rise in multidrug-resistant (MDR) organisms portends a serious global threat to the health care system with nearly untreatable infectious diseases, including pneumonia and its often fatal sequelae, acute respiratory distress syndrome (ARDS) and sepsis. Gram-negative bacteria (GNB), including Acinetobacter baumannii,...
Epidemiology and SurveillanceDistinct Mechanisms of Dissemination of NDM-1 Metallo-β-Lactamase in Acinetobacter Species in ArgentinaA 4-year surveillance of carbapenem-resistant Acinetobacter spp. isolates in Argentina identified 40 strains carrying blaNDM-1. Genome sequencing revealed that most were Acinetobacter baumannii, whereas seven represented other Acinetobacter spp. The A. baumannii...
PharmacologyPharmacodynamics of Meropenem against Acinetobacter baumannii in a Neutropenic Mouse Thigh Infection ModelAcinetobacter baumannii infections are difficult to treat and have limited treatment options. Carbapenems, including meropenem, are currently considered the first-line agents for the treatment of infections caused by Acinetobacter spp. The percentage of a 24-hour period that the concentration of...
Experimental TherapeuticsForging New Antibiotic Combinations under Iron-Limiting ConditionsPseudomonas aeruginosa is a multidrug-resistant nosocomial pathogen. We showed previously that thiostrepton (TS), a Gram-positive thiopeptide antibiotic, is imported via pyoverdine receptors and synergizes with iron chelator deferasirox (DSX) to inhibit the growth of P. aeruginosa and...
Mechanisms of ResistanceNovel Plasmid-Mediated tet(X5) Gene Conferring Resistance to Tigecycline, Eravacycline, and Omadacycline in a Clinical Acinetobacter baumannii IsolateA novel, plasmid-mediated, high-level tigecycline resistance tet(X) gene variant, tet(X5), was detected in a clinical Acinetobacter baumannii isolate from China in 2017. Tet(X5) shows 84.5% and 90.5% amino acid identity to Tet(X3) and Tet(X4), respectively, with similar binding sites and a comparable affinity for tetracyclines. The tet(X5)-...