Chelsie N. Geyer

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A multiplex, real-time TaqMan assay was designed to identify clinical isolates carrying plasmid-mediated ampC genes. The specificity and sensitivity of this assay were 100% when testing characterized AmpC/non-AmpC-producing isolates and randomly selected clinical isolates. This is a rapid assay that can be performed in a clinical microbiology laboratory.
Next-generation DNA sequencing (NGS) has progressed enormously over the past decade, transforming genomic analysis and opening up many new opportunities for applications in clinical microbiology laboratories. The impact of NGS on microbiology has been revolutionary, with new microbial genomic sequences being generated daily, leading to the development of(More)
High-resolution melting (HRM) analysis can be a diagnostic tool to evaluate the presence of resistance genes with the added bonus of discriminating sequence modifications. A real-time, multiplex PCR assay using HRM was designed for the detection of plasmid-mediated ampC genes. The specificity and sensitivity of this assay were 96% and 100%, respectively.
A previously designed end-point multiplex PCR assay and singleplex assays used to detect β-lactamase genes were evaluated using rapid PCR amplification methodology. Amplification times were 16-18 minutes with an overall detection time of 1.5 hours. Rapid PCR amplifications could decrease the time required to identify resistance mechanisms in Gram-negative(More)
OBJECTIVES High levels of β-lactamase production can impact treatment with a β-lactam/β-lactamase inhibitor combination. Goals of this study were to: (i) compare the mRNA and protein levels of CTX-M-15- and CTX-M-14-producing Escherichia coli from 18 different STs and 10 different phylotypes; (ii) evaluate the mRNA half-lives and establish a role for(More)
A novel metallo-β-lactamase gene, blaIMP-27, was identified in unrelated Proteus mirabilis isolates from two geographically distinct locations in the United States. Both isolates harbor blaIMP-27 as part of the first gene cassette in a class 2 integron. Antimicrobial susceptibility testing indicated susceptibility to aztreonam, piperacillin-tazobactam, and(More)
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