Evaluation of the utility and cost of secondary confirmatory testing for Neisseria gonorrhoeae identification from culture

Ellen G Avery; Joseph J Zeppa; Donald Brody Duncan; Kevin R Barker; Ramzi Fattouh; Larissa M Matukas; Candy Rutherford; Ana Cabrera; Prameet M Sheth; Vanessa Tran; Lee Goneau; Kevin Katz; Xena X Li; Robert Kozak

doi:10.1016/j.diagmicrobio.2024.116336

Evaluation of the utility and cost of secondary confirmatory testing for Neisseria gonorrhoeae identification from culture

Diagn Microbiol Infect Dis. 2024 Jul;109(3):116336. doi: 10.1016/j.diagmicrobio.2024.116336. Epub 2024 May 5.

Authors

Ellen G Avery¹, Joseph J Zeppa¹, Donald Brody Duncan², Kevin R Barker³, Ramzi Fattouh⁴, Larissa M Matukas⁴, Candy Rutherford⁵, Ana Cabrera⁶, Prameet M Sheth⁷, Vanessa Tran⁸, Lee Goneau⁹, Kevin Katz¹⁰, Xena X Li¹¹, Robert Kozak¹²

Affiliations

¹ Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada.
² Division of Medical Microbiology, Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada; Hamilton Regional Laboratory Medicine Program, Hamilton, ON, Canada.
³ Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada; Division of Microbiology, Department of Laboratory Medicine and Genetics, Trillium Health Partners, Mississauga, ON, Canada; Institute for Better Health, Trillium Health Partners, Mississauga, Ontario, Canada.
⁴ Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada; Division of Microbiology, Department of Laboratory Medicine, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada.
⁵ Hamilton Regional Laboratory Medicine Program, Hamilton, ON, Canada.
⁶ Pathology and Laboratory Medicine Department, London Health Sciences Centre, London, ON, Canada; Pathology and Laboratory Medicine Department, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Microbiology and Immunology Department, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
⁷ Division of Microbiology and Infectious Diseases, Kingston Health Sciences Center, Kingston, ON, Canada; Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada.
⁸ Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada; Public Health Ontario, Toronto, ON, Canada.
⁹ Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada; Dynacare Laboratory, Brampton, ON, Canada.
¹⁰ Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada; Shared Hospital Laboratory, Toronto, ON, Canada; Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
¹¹ Shared Hospital Laboratory, Toronto, ON, Canada; Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
¹² Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada; Shared Hospital Laboratory, Toronto, ON, Canada; Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Sciences Centre, Toronto, ON, Canada. Electronic address: rkozak@shn.ca.

PMID: 38723452
DOI: 10.1016/j.diagmicrobio.2024.116336

Abstract

Current guideline recommends the use of two identification methods for Neisseria gonorrhoeae. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) is now used for primary identification and may be sufficient for definitive identification of N. gonorrhoeae. The performance of three secondary tests (BactiCard, RapID NH and NET test) were compared using 45 bacterial isolates, including 37 Neisseria species. These secondary tests demonstrated diminished specificity (67% - 88%) for N. gonorrhoeae compared with MALDI-TOF. Additionally, data from six clinical microbiology laboratories was used to compare confirmatory test costs and the agreement of results with MALDI-TOF. Discrepancies were documented for 9.4% of isolates, though all isolates (n= 288) identified by MALDI-TOF as N. gonorrhoeae were confirmed by the reference laboratory. These data demonstrate that MALDI-TOF alone is sufficient for N. gonorrhoeae identification, as secondary did not add diagnostic value but do add costs to the testing process.

Keywords: Cost analysis; Neisseria gonorrhoeae; Public health; Secondary testing.

Publication types

Evaluation Study
Comparative Study

MeSH terms

Bacteriological Techniques / economics
Bacteriological Techniques / methods
Gonorrhea* / diagnosis
Gonorrhea* / microbiology
Humans
Neisseria gonorrhoeae* / classification
Neisseria gonorrhoeae* / isolation & purification
Sensitivity and Specificity*
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization* / economics
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization* / methods