TY - JOUR
T1 - Evaluating preanalytical sample storage parameters for nucleic acid-based detection of Neisseria gonorrhoeae
AU - Fernando, Janath A
AU - Krysiak, Marcelina
AU - Prestedge, Jacqueline
AU - Azzato, Francesca
AU - Williamson, Deborah A
AU - Pasricha, Shivani
N1 - Funding: DW is supported by an NHMRC Investigator Grant (APP1174555). JP and FA are both supported by an Australian Government Research Training Program Scholarship. This work was also supported by an Australian Research Council (ARC) Industrial Transformation Research Hub Grant (IH190100021).
PY - 2024/1/17
Y1 - 2024/1/17
N2 - Objectives: To ensure accurate diagnosis of infectious diseases, preanalytical factors should be considered when assessing specimen quality and subsequent test result. Accordingly, we aimed to systematically assess the effect of storage time, temperature and buffer on the analytical sensitivity of detecting the sexually transmitted pathogen, Neisseria gonorrhoeae across multiple molecular diagnostic platforms. Methods: Cultured N. gonorrhoeae was spiked into generic and commercial storage buffers and stored at four temperatures and five time points, ranging from -20°C to 37°C, over 30 days. Samples were processed using the Alinity m STI, Xpert CT/NG and Aptima Combo 2 nucleic acid amplification assays and an in-house quantitative PCR assay. A reduction in analytical sensitivity was defined as a significant (p<0.05) increase in cycle threshold (Ct) value relative to control samples. Results: In total, 2756 samples were processed, with N. gonorrhoeae detected in 99.2% of samples. With respect to time, analytical sensitivity was maintained from day 2 (113/120; 94.2%) up to day 30 (110/120; 91.7%) relative to baseline samples. With respect to temperature, analytical sensitivity was maintained from -20°C (147/150; 98.0%) up to 37°C (136/150; 90.7%) relative to baseline samples. Generic buffers, Viral Transport Medium and Amies Liquid Media showed a reduction in analytical sensitivity compared with their commercial counterparts, Aptima Multitest Swab Transport Media and Abbott Alinity transport buffer using select diagnostic assays; this reduction appeared temperature dependent, with the largest differences in median Ct values observed at 37°C (p<0.05). Conclusions: Increased prevalence of sample self-collection for sexually transmitted infections (STIs) warrants an evaluation of preanalytical sample storage variables on diagnostic testing performance. Here, across a range of time points, temperatures and storage buffers, N. gonorrhoeae was successfully detected, supporting flexibility in sample storage, and by extension the feasibility of analysing self-collected samples to improve access to STI testing.
AB - Objectives: To ensure accurate diagnosis of infectious diseases, preanalytical factors should be considered when assessing specimen quality and subsequent test result. Accordingly, we aimed to systematically assess the effect of storage time, temperature and buffer on the analytical sensitivity of detecting the sexually transmitted pathogen, Neisseria gonorrhoeae across multiple molecular diagnostic platforms. Methods: Cultured N. gonorrhoeae was spiked into generic and commercial storage buffers and stored at four temperatures and five time points, ranging from -20°C to 37°C, over 30 days. Samples were processed using the Alinity m STI, Xpert CT/NG and Aptima Combo 2 nucleic acid amplification assays and an in-house quantitative PCR assay. A reduction in analytical sensitivity was defined as a significant (p<0.05) increase in cycle threshold (Ct) value relative to control samples. Results: In total, 2756 samples were processed, with N. gonorrhoeae detected in 99.2% of samples. With respect to time, analytical sensitivity was maintained from day 2 (113/120; 94.2%) up to day 30 (110/120; 91.7%) relative to baseline samples. With respect to temperature, analytical sensitivity was maintained from -20°C (147/150; 98.0%) up to 37°C (136/150; 90.7%) relative to baseline samples. Generic buffers, Viral Transport Medium and Amies Liquid Media showed a reduction in analytical sensitivity compared with their commercial counterparts, Aptima Multitest Swab Transport Media and Abbott Alinity transport buffer using select diagnostic assays; this reduction appeared temperature dependent, with the largest differences in median Ct values observed at 37°C (p<0.05). Conclusions: Increased prevalence of sample self-collection for sexually transmitted infections (STIs) warrants an evaluation of preanalytical sample storage variables on diagnostic testing performance. Here, across a range of time points, temperatures and storage buffers, N. gonorrhoeae was successfully detected, supporting flexibility in sample storage, and by extension the feasibility of analysing self-collected samples to improve access to STI testing.
KW - Humans
KW - Neisseria gonorrhoeae/genetics
KW - Nucleic acid amplification techniques/methods
KW - Chlamydia trachomatis/genetics
KW - Sensitivity and specificity
KW - Chlamydia infections/diagnosis
KW - Gonorrhea/diagnosis
KW - Sexually transmitted Diseases
KW - Nucleic acids
U2 - 10.1136/sextrans-2023-055859
DO - 10.1136/sextrans-2023-055859
M3 - Article
C2 - 38050184
SN - 1368-4973
VL - 100
SP - 48
EP - 51
JO - Sexually Transmitted Infections
JF - Sexually Transmitted Infections
IS - 1
ER -
