Table 5. Test characteristics Accumast plates to identify bacteria associated with clinical mastitis determined by 16S rRNA sequencing.
| Parameter | ||||
|---|---|---|---|---|
| Bacterial group | Tests, (n/n) | PPV1, % (CI2) | κ 3, % | κ P-value |
| Overall | 214 | 95.3 (95.1–95.5) | 0.89 (0.83–0.95) | <0.0001 |
| Escherichia | 30/214 | 96.7 (95.5–97.8) | 0.85 (0.76–0.95) | <0.0001 |
| Enterococcus | 3/214 | 100.0 (100.0–100.0) | 1.000 (1.0–1.00) | <0.0001 |
| Other Gram-negatives | 23/214 | 100.0 (100.0–100.0) | 0.95 (0.88–1.00) | <0.0001 |
| Staphylococcus | 17/214 | 88.2 (84.5–91.9) | 0.93 (0.83–1.00) | <0.0001 |
| Streptococcus | 141/214 | 95.0 (94.7–95.3) | 0.91 (0.86–0.97) | <0.0001 |
Isolates from cases of clinical mastitis cultured using Accumast plates from October 2014 to December 2014 were subjected to 16S rRNA gene sequencing for genus level determination of bacterial growth. Only positive results were available for comparison, therefore only PPV and the Cohen’s kappa coefficient between 16S rRNA sequencing and Accumast were calculated.
1 Positive predictive value.
2 95% confidence interval.
3 Cohen’s kappa coefficient. κ ≤ 0 denotes poor agreement; 0.01 to 0.20 denotes slight agreement; 0.21 to 0.40 denotes fair agreement; 0.41 to 0.60 denotes moderate agreement; 0.61 to 0.80 denotes substantial agreement and 0.81 to 1.00 denotes almost perfect agreement.