Genomic evaluation of phenotypic antibiotic susceptibility patterns as a surrogate for MRSA relatedness and putative transmission during outbreak investigations.

Antibiograms have been used during outbreak investigations for decades as a surrogate for genetic relatedness of Methicillin-resistant (MRSA). In this study, we evaluate the accuracy of antibiograms in detecting transmission, using genomic epidemiology as the reference standard. We analysed epidemiological and genomic data from 1,465 patients and 1,465 MRSA isolates collected at a single clinical microbiology laboratory in the United Kingdom over a one-year period.

The mutational landscape of Staphylococcus aureus during colonisation.

Staphylococcus aureus is an important human pathogen and a commensal of the human nose and skin. Survival and persistence during colonisation are likely major drivers of S. aureus evolution.

Phenotypic and genotypic correlates of the sodium bicarbonate-responsive phenotype among methicillin-resistant Staphylococcus aureus isolates from skin and soft-tissue infections.

Objectives: The objective of this study is to assess the frequency of the novel sodium bicarbonate (NaHCO)-responsive phenotype, wherein clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates are rendered susceptible to standard-of-care β-lactams in the presence of NaHCO, in a collection of 103 clinical U.S. MRSA skin and soft-tissue infection (SSTI) isolates and 22 clinical European SSTI isolates.

Evolution and host-specific adaptation of .

The major human bacterial pathogen causes multidrug-resistant infections in people with underlying immunodeficiencies or structural lung diseases such as cystic fibrosis (CF). We show that a few environmental isolates, driven by horizontal gene acquisition, have become dominant epidemic clones that have sequentially emerged and spread through global transmission networks over the past 200 years. These clones demonstrate varying intrinsic propensities for infecting CF or non-CF individuals (linked to specific transcriptional changes enabling survival within macrophages); have undergone multiple rounds of convergent, host-specific adaptation; and have eventually lost their ability to transmit between different patient groups.

Evaluating the impact of genomic epidemiology of methicillin-resistant (MRSA) on hospital infection prevention and control decisions.

Genomic epidemiology enhances the ability to detect and refute methicillin-resistant (MRSA) outbreaks in healthcare settings, but its routine introduction requires further evidence of benefits for patients and resource utilization. We performed a 12 month prospective study at Cambridge University Hospitals NHS Foundation Trust in the UK to capture its impact on hospital infection prevention and control (IPC) decisions. MRSA-positive samples were identified via the hospital microbiology laboratory between November 2018 and November 2019.