Lao-Tzu Allan-Blitz1,2, Olivia L Ellis3,4, Rachel Wee5, Annie Truong5, Samantha M Ebeyan5, Lit Yeen Tan5, Elisa Mokany5, Risa Flynn6, Jeffrey D Klausner7,8. 1. Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA. 2. Department of Medicine, Boston Children's Hospital, Boston, MA, USA. 3. Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles, CA, USA. 4. Department of Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA. 5. SpeeDx Pty Ltd, Sydney, Australia. 6. Lesbian Gay Bisexual Transgender Health Center, Los Angeles, CA, USA. 7. Division of Infectious Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA. 8. Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, CA, USA.
Abstract
BACKGROUND: The emergence of drug-resistant Neisseria gonorrhoeae has prompted the development of rapid molecular assays designed to determine antimicrobial susceptibility. One common assay uses high-resolution melt analysis to target codon 91 of the gyrase A gene (gyrA) to predict N. gonorrhoeae susceptibility to ciprofloxacin. METHODS: We extracted DNA from remnant clinical specimens that had previously tested positive for N. gonorrhoeae using the Aptima Combo 2 for CT/NG assay (Hologic, San Diego, CA, USA). We selected DNA extracts from specimens with indeterminate, WT and mutant gyrA genotype results from a previous study using high-resolution melt analysis to detect the gyrA codon 91 mutation. We re-tested those specimens using the recently CE-marked ResistancePlus GC (beta) assay (SpeeDx, Sydney, Australia). RESULTS: Of 86 specimens with indeterminate gyrA genotypes on high-resolution melt analysis, the ResistancePlus GC (beta) assay (SpeeDx) identified 30 (35%) WT, 22 (26%) mutant and 34 (40%) indeterminate gyrA genotypes. CONCLUSIONS: The ResistancePlus GC (beta) assay showed improved N. gonorrhoeae gyrA genotype determination compared with a prior gyrA genotypic high-resolution melt assay.
BACKGROUND: The emergence of drug-resistant Neisseria gonorrhoeae has prompted the development of rapid molecular assays designed to determine antimicrobial susceptibility. One common assay uses high-resolution melt analysis to target codon 91 of the gyrase A gene (gyrA) to predict N. gonorrhoeae susceptibility to ciprofloxacin. METHODS: We extracted DNA from remnant clinical specimens that had previously tested positive for N. gonorrhoeae using the Aptima Combo 2 for CT/NG assay (Hologic, San Diego, CA, USA). We selected DNA extracts from specimens with indeterminate, WT and mutant gyrA genotype results from a previous study using high-resolution melt analysis to detect the gyrA codon 91 mutation. We re-tested those specimens using the recently CE-marked ResistancePlus GC (beta) assay (SpeeDx, Sydney, Australia). RESULTS: Of 86 specimens with indeterminate gyrA genotypes on high-resolution melt analysis, the ResistancePlus GC (beta) assay (SpeeDx) identified 30 (35%) WT, 22 (26%) mutant and 34 (40%) indeterminate gyrA genotypes. CONCLUSIONS: The ResistancePlus GC (beta) assay showed improved N. gonorrhoeaegyrA genotype determination compared with a prior gyrA genotypic high-resolution melt assay.
Authors: Jolinda de Korne-Elenbaas; Arno Pol; Jacqueline Vet; Mirjam Dierdorp; Alje P van Dam; Sylvia M Bruisten Journal: Sex Transm Dis Date: 2020-04 Impact factor: 2.830