Table 1.
Overview of analytical studies evaluating available chromogenic media for detection of ESBL producersa
| Chromogenic medium | Organism(s) tested (n) | Proportion of ESBL producers in total tested strains (%) | Incubation time (h) | Comparator(s) | Sensitivity (%) | Specificity (%) | Reference |
|---|---|---|---|---|---|---|---|
| chromID ESBL | E. coli (334) | 291/505 (57.6) | 18–24 | EbSA | 97.3 | 93.9 | 16 |
| Klebsiella spp. (124) | |||||||
| Proteus spp. (42) | |||||||
| Salmonella spp. (3) | |||||||
| Shigella spp. (2) | |||||||
| Enterobacter spp. (90) | 65/137 (47.4) | 18–24 | EbSA | 98.5 | 44.3 | 16 | |
| Citrobacter spp. (30) | |||||||
| Morganella morganii (9) | |||||||
| Serratia marcescens (6) | |||||||
| Providencia spp. (2) | |||||||
| Enterobacteriaceae (156) | 98/200 (49) | 24 | Brilliance ESBL | ND | ND | 10 | |
| Gram-negative nonfermenters (44) | |||||||
| Enterobacteriaceae and Pseudomonas spp. (150) | 101/150 (67.3) | ND | CHROMagar CTX, CHROMagar ECC + CTXc or CAZc | 98 | 25.5 | 21 | |
| E. coli (72) | 99/114 (86.8) | 18–24 and 48 | Vitek 2, Phoenix | 95.8 | 10.5 | 8 | |
| Klebsiella pneumoniae (21) | |||||||
| K. oxytoca (4) | |||||||
| Enterobacter cloacae (11) | |||||||
| Enterobacter aerogenes (1) | |||||||
| S. marcescens (1) | |||||||
| Citrobacter koseri (1) | |||||||
| Proteus mirabilis (1) | |||||||
| Proteus vulgaris (1) | |||||||
| M. morganii (1) | |||||||
| Brilliance ESBL | Enterobacteriaceae (156) | 98/200 (49) | 24 | chromID ESBL | ND | ND | 10 |
| Gram-negative nonfermenters (44) | |||||||
| CHROMagar CTX | Enterobacteriaceae and Pseudomonas spp. (150) | 70b/150 (46.6) | ND | chromID ESBL, CHROMagar ECC + CTXc or CAZc | 100 | 64.2 | 21 |
a
CTX, cefotaxime; CAZ, ceftazidime; ND, not described.
b
CTX-M producers.
c
Cefotaxime or ceftazidime was incorporated at concentrations of 1, 2, 4, and 8 μg/ml.