In-patient evolution of a high-persister strain with reduced in vivo antibiotic susceptibility.

Gram-negative bacterial bloodstream infections (GNB-BSI) are common and frequently lethal. Despite appropriate antibiotic treatment, relapse of GNB-BSI with the same bacterial strain is common and associated with poor clinical outcomes and high healthcare costs. The role of persister cells, which are sub-populations of bacteria that survive for prolonged periods in the presence of bactericidal antibiotics, in relapse of GNB-BSI is unclear.

Progressive Sub-MIC Exposure of 43816 to Cephalothin Induces the Evolution of Beta-Lactam Resistance without Acquisition of Beta-Lactamase Genes.

Bacterial exposure to antibiotic concentrations below the minimum inhibitory concentration (MIC) may result in a selection window allowing for the rapid evolution of resistance. These sub-MIC concentrations are commonly found in soils and water supplies in the greater environment. This study aimed to evaluate the adaptive genetic changes in 43816 after prolonged but increasing sub-MIC levels of the common antibiotic cephalothin over a fourteen-day period.

Overcoming biological barriers to improve treatment of a Staphylococcus aureus wound infection.

Chronic wounds frequently become infected with bacterial biofilms which respond poorly to antibiotic therapy. Aminoglycoside antibiotics are ineffective at treating deep-seated wound infections due to poor drug penetration, poor drug uptake into persister cells, and widespread antibiotic resistance. In this study, we combat the two major barriers to successful aminoglycoside treatment against a biofilm-infected wound: limited antibiotic uptake and limited biofilm penetration.

Antibiotic Tolerance and Treatment Outcomes in Cystic Fibrosis Methicillin-Resistant Staphylococcus aureus Infections.

Methicillin-resistant Staphylococcus aureus (MRSA) is highly prevalent in U.S. cystic fibrosis (CF) patients and is associated with worse clinical outcomes in CF.

Removing the Graduate Record Examination as an Admissions Requirement Does Not Impact Student Success.

The predictive validity of components of the Graduate Record Examination (GRE) on student success is inconsistent, and the test itself has been shown to be a barrier for prospective students historically underrepresented in graduate programs. We analyzed three admissions cycles for the Master of Public Health degree at the Boston University School of Public Health before (2016, 2017, 2018) and after (2019, 2020, 2021) eliminating the GRE for diversity and quality of applications, student success, and employment outcomes. We observed increases in diversity (e.

Porin loss in Klebsiella pneumoniae clinical isolates impacts production of virulence factors and survival within macrophages.

Clinical isolates of Klebsiella pneumoniae are often resistant to beta-lactam antibiotics via the acquisition of extended spectrum beta lactamase (ESBL) enzymes paired with loss of one or both major outer membrane porins. It has been well established that loss of OmpK35 and/or OmpK36 correlates with increased minimum inhibitory concentrations of antibiotics that target the peptidoglycan. However, little is known concerning the downstream effects porin loss might have on other major virulence factors such as the polysaccharide capsule or LPS.