pISSN 2234-3806eISSN 2234-3814
Categorical agreement between fluconazole susceptibility results determined by DDT using two inocula and the BMD method after each incubation time for the readable
| Species (N tested) | Incubation time (hr) | DDT using a standard inoculum (McFarland 0.5) | DDT using a large inoculum (McFarland 2.5) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Readable N (%) | % CA | N (%) of isolates with discrepancies | Readable N (%) | % CA | N (%) of isolates with discrepancies | ||||||
| VME | ME | Minor | VME | ME | Minor | ||||||
(66) |
10 | 5 (7.6) | 100.0 | 0 | 0 | 0 | 26 (39.4)† | 100.0 | 0 | 0 | 0 |
| 12 | 38 (57.6) | 100.0 | 0 | 0 | 0 | 55 (83.3)† | 96.4 | 1 (1.8) | 0 | 1 (1.8) | |
| 14 | 63 (95.5) | 96.8 | 2 (3.2) | 0 | 0 | 63 (95.5)† | 96.8 | 1 (1.6) | 0 | 1 (1.6) | |
| 16 | 63 (95.5) | 95.2 | 2 (3.2) | 0 | 1 (1.6) | 66 (100.0) | 95.5 | 1 (1.5) | 0 | 2 (3.0) | |
| 18 | 63 (95.5) | 95.2 | 2 (3.2) | 0 | 1 (1.6) | 66 (100.0) | 95.5 | 2 (3.0) | 0 | 1 (1.5) | |
| 20 | 64 (97.0) | 96.9 | 2 (3.1) | 0 | 0 | 66 (100.0) | 95.5 | 1 (1.5) | 0 | 2 (3.0) | |
| 22 | 66 (100.0) | 97.0 | 2 (3.0) | 0 | 0 | 66 (100.0) | 97.0 | 1 (1.5) | 0 | 1 (1.5) | |
| 24 | 66 (100.0) | 97.0 | 2 (3.0) | 0 | 0 | 66 (100.0) | 97.0 | 1 (1.5) | 0 | 1 (1.5) | |
(69) |
10 | 46 (66.7) | 100.0 | 0 | 0 | 0 | 60 (87.0)† | 100.0 | 0 | 0 | 0 |
| 12 | 60 (87.0) | 100.0 | 0 | 0 | 0 | 68 (98.6)† | 98.5 | 0 | 0 | 1 (1.5) | |
| 14 | 67 (97.1) | 98.5 | 0 | 0 | 1 (1.5) | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | |
| 16 | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | |
| 18 | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | |
| 20 | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | |
| 22 | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | 69 (100.0) | 97.1 | 0 | 0 | 2 (2.9) | |
| 24 | 69 (100.0) | 98.6 | 0 | 0 | 1 (1.4) | 69 (100.0) | 94.2 | 0 | 0 | 4 (5.8) | |
(29) |
10 | 0 (0.0) | - | 0 | 0 | 0 | 2 (6.9) | 100.0 | 0 | 0 | 0 |
| 12 | 1 (3.4) | 100.0 | 0 | 0 | 0 | 24 (82.8)† | 95.8 | 0 | 0 | 1 (4.2) | |
| 14 | 19 (65.5) | 68.4 | 1 (5.3) | 0 | 5 (26.3) | 26 (89.7)† | 92.3† | 0 | 0 | 2 (7.7) | |
| 16 | 22 (75.9) | 90.9 | 0 | 0 | 2 (9.1) | 29 (100.0)† | 93.1 | 0 | 0 | 2 (6.9) | |
| 18 | 25 (86.2) | 92.0 | 0 | 0 | 2 (8.0) | 29 (100.0)† | 93.1 | 0 | 0 | 2 (6.9) | |
| 20 | 29 (100.0) | 89.7 | 2 (6.9) | 0 | 1 (3.4) | 29 (100.0) | 93.1 | 0 | 0 | 2 (6.9) | |
| 22 | 29 (100.0) | 89.7 | 2 (6.9) | 0 | 1 (3.4) | 29 (100.0) | 93.1 | 0 | 0 | 2 (6.9) | |
| 24 | 29 (100.0) | 89.7 | 1 (3.4) | 0 | 2 (6.9) | 29 (100.0) | 96.6 | 0 | 0 | 1 (3.4) | |
(24) |
10 | 15 (62.5) | 93.3 | 0 | 0 | 1 (6.7) | 22 (91.7)† | 95.5 | 1 (4.5) | 0 | 0 |
| 12 | 21 (87.5) | 90.5 | 1 (4.8) | 0 | 1 (4.8) | 24 (100.0) | 87.5 | 1 (4.2) | 0 | 2 (8.3) | |
| 14 | 24 (100.0) | 91.7 | 1 (4.2) | 0 | 1 (4.2) | 24 (100.0) | 91.7 | 1 (4.2) | 0 | 1 (4.2) | |
| 16 | 24 (100.0) | 91.7 | 1 (4.2) | 0 | 1 (4.2) | 24 (100.0) | 95.8 | 1 (4.2) | 0 | 0 | |
| 18 | 24 (100.0) | 95.8 | 1 (4.2) | 0 | 0 | 24 (100.0) | 95.8 | 1 (4.2) | 0 | 0 | |
| 20 | 24 (100.0) | 95.8 | 0 | 0 | 1 (4.2) | 24 (100.0) | 95.8 | 1 (4.2) | 0 | 0 | |
| 22 | 24 (100.0) | 95.8 | 0 | 0 | 1 (4.2) | 24 (100.0) | 95.8 | 0 | 0 | 1 (4.2) | |
| 24 | 24 (100.0) | 95.8 | 0 | 0 | 1 (4.2) | 24 (100.0) | 95.8 | 0 | 0 | 1 (4.2) | |
| Total (188) | 10 | 66 (35.1) | 98.5 | 0 | 0 | 1 (1.5) | 110 (58.5)† | 99.1 | 1 (0.9) | 0 | 0 |
| 12 | 120 (63.8) | 98.3 | 1 (0.8) | 0 | 1 (0.8) | 171 (91.0)† | 95.9 | 2 (1.2) | 0 | 5 (2.9) | |
| 14 | 173 (92.0) | 93.6 | 4 (2.3) | 0 | 7 (4.0) | 182 (96.8)† | 96.2 | 2 (1.1) | 0 | 5 (2.7) | |
| 16 | 178 (94.7) | 95.5 | 3 (1.7) | 0 | 5 (2.8) | 188 (100.0)† | 96.3 | 2 (1.1) | 0 | 5 (2.7) | |
| 18 | 181 (96.3) | 96.1 | 3 (1.7) | 0 | 4 (2.2) | 188 (100.0)† | 96.3 | 3 (1.6) | 0 | 4 (2.1) | |
| 20 | 186 (98.9) | 96.2 | 4 (2.2) | 0 | 3 (1.6) | 188 (100.0) | 96.3 | 2 (1.1) | 0 | 5 (2.7) | |
| 22 | 188 (100.0) | 96.3 | 4 (2.1) | 0 | 3 (1.6) | 188 (100.0) | 96.3 | 1 (0.5) | 0 | 6 (3.2) | |
| 24 | 188 (100.0) | 96.3 | 3 (1.6) | 0 | 4 (2.1) | 188 (100.0) | 95.7 | 1 (0.5) | 0 | 7 (3.7) | |
*BMD method was conducted strictly according to CLSI M27-ED4 document (24-hour incubation), but DDT was modified with the use of two cell suspensions (McFarland 0.5, standard inoculum; and 2.5, large inoculum), and inhibition zones were read at 2-hour intervals from 10 hours to 24 hours [15]. †
Abbreviations: BMD, broth microdilution; CA, categorical agreement; DDT, disk diffusion testing; ME, major error; Minor, minor error; VME, very major error.
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