72-Hour transport recovery of antimicrobial resistant Neisseria gonorrhoeae isolates using the InTray® GC method

Abstract

Recovery of Neisseria gonorrhoeae isolates exposed to a range of transport times and temperatures was quantitatively assessed for two transport devices, BioMed Diagnostics’ InTray GC® and Copan Diagnostics’ Liquid Amies Elution Swab (ESwab®) Collection and Transport System. Respective devices were inoculated with N. gonorrhoeae, exposed to simulated transport conditions and spread-plated from serial dilutions in duplicates onto chocolate agar in order to count CFU (colony-forming units) in the range of 25–250. Baseline CFU/mL averages of time-zero transport for each device was compared to either 24 hour (Eswab) or 72 hour (InTray GC) CFU/mL average to assess recovery of six clinical isolates of N. gonorrhoeae, and differences showing no greater than a 3 log10 (± 10%) decline between comparative time points qualified as acceptable. Our findings suggest that the InTray GC system has the potential to transport clinical isolates for ≤72 hours with acceptable N. gonorrhoeae recovery.

Devices for the transport and microbiological detection of Neisseria gonorrhoeae in sexual health clinic samples: a prospective comparative study

“…7,10,11 In our study, the In-TrayÔ device had the lowest concordance levels with both GC plating and NAAT results, but in a controlled experiment with different N. gonorrhoeae strains, recovery rates with use of InTrayÔ showed less than 10% reduction in average log 10 Colony Forming Units (CFUs) per millilitre in a controlled experiment. 14 Two clinic-based studies on patient samples, both comparing InTrayÔ with modified Thayer-Martin agar plates, found a concordance of >0.85 but InTrayÔ being negative more often when the Thayer-Martin agar plate samples were positive. 15,16 To our knowledge, this is the first time results on relative performance of Sigma VCMÔ to standard direct GC plating has been reported; based on outcome distribution and concordance with both standard GC plates and PCR, it does not outperform the others.…”