Volume 32, Supplement –Summer 2026
SUPPLEMENT ISSUE
Supplement
Evaluation of Detection Methods for Wastewater Surveillance of Antimicrobial-Resistant Bacteria from Healthcare Facilities
Table 5
Effects of sample handling and storage conditions on gene abundance determined by qPCR in study of detection methods for wastewater surveillance of antimicrobial-resistant bacteria from healthcare facilities*
| Factor | 16S rRNA gene | blaKPC | blaVIM | blaOXA-48-like | blaKPC/16S rRNA† | blaVIM/16S rRNA† |
|---|---|---|---|---|---|---|
| Overall model F (p value) |
1.98 (0.02) |
2.23 (0.008) |
6.33 (<0.001) |
NS |
3.99 (<0.01) |
9.67 (<0.001) |
| Source of variation | ||||||
| Hold time‡ | 38 (0.002) | 25 (0.01) | 30 (<0.001) | NA§ | NS | 31 (<0.001) |
| Hold temp¶ | NS | NS | 16 (0.01) | NA | NS | 10 (0.008) |
| Hold method | 41 (<0.001) | 42 (<0.001) | 30.1 (<0.001) | NA | 27 (<0.001) | 24 (<0.001) |
| Time × temp | NS | NS | 12.5 (0.008) | NA | NS | 11 (0.002) |
| Temp × method | NS | NS | NS | NA | NS | 15 (0.007) |
| Time × method | NS | NS | 9 (0.04) | NA | 22 (<0.001) | 9 (0.006) |
| Time × temp × method | NS | 15 (0.05) | Not estimable** | NA | 27 (<0.001) | Not estimable** |
*Source of variation is percent of total variation (p value) of type 1 error for the general linearized model. NA, not applicable; NS, not significant; qPCR, quantitative PCR. †Calculation based on log10 ARG/mL divided by log10 16S rRNA gene/mL. ‡Hold times were 1, 7, or 29 days. §The overall model was not significant for this gene. ¶Temperature was 4°C, −20°C, or −70°C. #Hold methods: extracted immediately versus raw samples held at temperature, glycerol preserved unprocessed samples, polyethylene glycol concentrated and resuspended samples, or nucleic acids extracted and stored. **These values were not estimable because of limited degrees of freedom.