Table 3.
Validity values of the universal 16S rRNA gene PCR for the detection of colonizationa
| Test | No. of cases/total (%) (95% confidence interval) |
|||||||
|---|---|---|---|---|---|---|---|---|
| Routine GSb |
Excellence GSc |
|||||||
| S | SP | PPV | NPV | S | SP | PPV | NPV | |
| PCR with any sample | 34/46 (73.9) (60.1–87.7) | 142/173 (81.5) (76.1–88.1) | 34/65 (52.3) (39.4–65.2) | 142/154 (92.2) (87.7–96.8) | 44/83 (53.0) (41.7–64.4) | 115/136 (84.6) (78.1–91.0) | 44/65 (67.7) (55.6–79.8) | 115/154 (74.7) (67.5–81.9) |
| PCR with CABS | 21/46 (45.7) (30.2–61.1) | 157/173 (90.6) (86.2–95.4) | 21/37 (56.8) (39.4–74.1) | 157/182 (86.3) (81.0–91.5) | 23/83 (27.7) (17.5–37.9) | 122/136 (89.7) (84.2–95.2) | 23/37 (62.2) (45.2–79.1) | 122/182 (67.0) (59.9–74.1) |
| PCR with CAAS | 24/46 (52.2) (36.7–67.7) | 155/173 (89.6) (84.8–94.4) | 24/42 (57.1) (41.0–73.3) | 155/177 (87.6) (82.4–92.7) | 29/83 (34.9) (24.1–45.8) | 123/136 (90.4) (85.1–95.8) | 29/42 (69.0) (53.9–84.2) | 123/177 (69.5) (62.4–76.6) |
| PCR with PSF | 18/46 (39.1) (23.9–54.3) | 157/173 (90.6) (86.2–95.4) | 18/34 (52.9) (34.7–71.2) | 157/185 (84.8) (79.4–90.3) | 25/83 (30.1) (19.7–40.6) | 127/136 (93.4) (88.8–97.9) | 25/34 (73.5) (57.2–89.8) | 127/185 (68.6) (61.7–75.6) |
| PCR with ISB | 23/46 (50.0) (34.5–65.5) | 159/173 (91.9) (87.6–96.3) | 23/37 (62.2) (45.2–79.1) | 159/182 (87.4) (82.3–92.5) | 29/83 (34.9) (24.1–45.8) | 128/136 (94.1) (89.8–98.4) | 29/37 (78.4) (63.8–93.0) | 128/182 (70.3) (63.4–77.2) |
a
GS, gold standard; S, sensitivity; SP, specificity; PPV, positive predictive value; NPV, negative predictive value; CABS, port content aspirate before sonication; CAAS, port content aspirate after sonication; PSF, port sonication fluid; ISB, port internal surface biofilm.
b
Incubation of VAP cultures under aerobic conditions.
c
Incubation of VAP cultures under aerobic plus anaerobic conditions.