Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Life Sciences
Updating Molecular Diagnostics For Detecting Methicillin- Susceptible And Methicillin-Resistant Staphylococcus Aureus Isolates In Blood Culture Bottles, Fred C. Tenover, Isabella A. Tickler, Victoria M. Le, Scott Dewell, Rodrigo E. Mendes, Richard V. Goering, Mrsa Consortium
Updating Molecular Diagnostics For Detecting Methicillin- Susceptible And Methicillin-Resistant Staphylococcus Aureus Isolates In Blood Culture Bottles, Fred C. Tenover, Isabella A. Tickler, Victoria M. Le, Scott Dewell, Rodrigo E. Mendes, Richard V. Goering, Mrsa Consortium
Biology Faculty Publications
Molecular diagnostic tests can be used to provide rapid identification of staphylococcal species in blood culture bottles to help improve antimicrobial stewardship. However, alterations in the target nucleic acid sequences of the microorganisms or their antimicrobial resistance genes can lead to false-negative results. We determined the whole-genome sequences of 4 blood culture isolates of Staphylococcus aureus and 2 control organisms to understand the genetic basis of genotypephenotype discrepancies when using the Xpert MRSA/SA BC test (in vitro diagnostic medical device [IVD]). Three methicillin-resistant S. aureus (MRSA) isolates each had a different insertion of a genetic element in the staphylococcal cassette …
Emergence Of Oxacillin Resistance In Stealth Methicillin-Resistant Staphylococcus Aureus Due To Meca Sequence Instability, Richard V. Goering, Erin A. Swartzendriber, Anne E. Obradovich, Isabella A. Tickler, Fred C. Tenover
Emergence Of Oxacillin Resistance In Stealth Methicillin-Resistant Staphylococcus Aureus Due To Meca Sequence Instability, Richard V. Goering, Erin A. Swartzendriber, Anne E. Obradovich, Isabella A. Tickler, Fred C. Tenover
Biology Faculty Publications
Staphylococcus aureus strains that possess a mecA gene but are phenotypically susceptible to oxacillin and cefoxitin (OS-MRSA) have been recognized for over a decade and are a challenge for diagnostic laboratories. The mechanisms underlying the discrepancy vary from isolate to isolate. We characterized seven OS-MRSA clinical isolates of six different spa types from six different states by whole-genome sequencing to identify the nucleotide sequence changes leading to the OS-MRSA phenotype. The results demonstrated that oxacillin susceptibility was associated with mutations in regions of nucleotide repeats within mecA. Subinhibitory antibiotic exposure selected for secondary mecA mutations that restored oxacillin resistance. …