Table 3.
Comparison between phenotypic and genotypic results of carbapenem resistance among different GNB strains
| Bacterial species | Resistant isolates n |
Phenotypic testa n (%) |
Carbapenemase genesb n (%) |
Correlation with carbapenemase | ESBL genesc n (%) |
Correlation with ESBL | |||
|---|---|---|---|---|---|---|---|---|---|
| positive | negative | positive | negative | p-value | positive | negative | p-value | ||
| K. pneumoniae | 82 | 71 (86.6) | 11(13.4) | 63 (76.8) | 19 (23.2) | 0.0000031 | 72 (87.8) | 10 (12.2) | 0.017 |
| E.coli | 28 | 26 (92.8) | 2 (7.2) | 12 (42.8) | 16 (57.2) | 0.00079 | 19 (67.8) | 9 (32.2) | 0.123 |
| P. aeruginosa | 45 | 33 (73) | 12 (27) | 19 (42) | 26 (58) | 0.0015 | 39 (86.6) | 6 (13.4) | 0.038 |
| A. baumannii | 36 | 30 (83.3) | 6 (16.7) | 18 (50) | 18 (50) | 0.022 | 31 (86) | 5 (14) | 0.14 |
| Other GNBd | 15 | 11 (73) | 4 (27) | 9 (60) | 6 (40) | 0.055 | 15 (100) | 0 (0) | 0.08 |
| Total | 206 | 171 (83) | 35 (17) | 121(58.7) | 85 (41.3) | 0.0000001 | 176 (85.4) | 30 (14.6) | 0.01 |
aPhenotypic test include: EDTA, Borinic Acid and Modified Hodge Test
bCarbapenemase genes include: NDM, VIM, IMP and OXA-48
cESBL genes include: CTX-M, SHV, and TEM
dOther GNB include: Citrobacter species (3), Burkholderia spp. (2), Enterobacter Spp.(2), Serratia species (1), Proteus spp. (2), Stenotrophomonas maltophilia (3), Vibrio vurneficus (1), and Morganella morganii (1)