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Volume 32, Supplement –Summer 2026
SUPPLEMENT ISSUE
Supplement
Evaluation of Detection Methods for Wastewater Surveillance of Antimicrobial-Resistant Bacteria from Healthcare Facilities
Table 1
Sample types, frequency of collection, numbers of samples, and handling methods for trend analysis over 16 months in study of detection methods for wastewater surveillance of antimicrobial-resistant bacteria from healthcare facilities*
| Sample type | Frequency of collection | No. days of observations | Replicates | Total no. of samples, including replicates† | Handling method‡ |
|---|---|---|---|---|---|
| Composite | Weekly or twice weekly | 61 | Primarily laboratory-split triplicates | 297 | 40-mL concentrated for extraction |
| Sewer biofilm | Weekly or monthly | 16 | Field duplicates | 32 | Sponge shaken in sterile 1X PBS for 10 min, supernatant concentrated for extraction |
| Passive | Weekly or twice weekly | 53 | Primarily field duplicates | 110 | Tampon shaken in sterile 1X PBS for 10 min, supernatant concentrated for extraction |
*PBS, phosphate-buffered saline. †Total number of samples includes days when more replicates were collected (e.g., 6 replicates rather than the typical 3 replicates). ‡All samples were stored at 4°C until processing, which occurred within 24 hours of collection. All samples were processed by concentration with polyethylene glycol/NaCl precipitation for 2 hours at 4°C, centrifugation at 31,400 × g, and then nucleic acids were extracted from the pellet (Appendix).