Table 2.
Distribution of the 107 Enterobacteriaceae isolates included in the study and their ESBL genes
| Enterobacteriaceae group and species | No. of isolates (% of total) | No. of ESBL producersa (% of total) | No. of isolates with indicated ESBL type |
||
|---|---|---|---|---|---|
| CTX-M | SHV | TEM | |||
| Group 1 | 28 (26) | 21 (40) | |||
| Escherichia coli | 27 | 20 | 18 | 2 | |
| Proteus mirabilis | 1 | 1 | 1 | ||
| Group 2 | 25 (23) | 18 (35) | |||
| Klebsiella pneumoniae | 21 | 17 | 10 | 2 | 5 |
| Klebsiella oxytoca | 2 | 0 | |||
| Citrobacter koseri | 2 | 1 | 1 | ||
| Group 3 | 54 (51) | 13 (25) | |||
| Enterobacter cloacae | 26 | 10 | 10 | ||
| Enterobacter aerogenes | 10 | 2 | 2 | ||
| Citrobacter freundii | 10 | 0 | |||
| Morganella morganii | 4 | 0 | |||
| Serratia marcescens | 2 | 1* | |||
| Hafnia alvei | 2 | 0 | |||
| Total | 107 (100) | 52 (49) | 31 (60) | 12 (23) | 8 (15) |
a
ESBL production was defined as positive based on the PCR results for ESBL genes, except for one strain (indicated by the asterisk) that was ESBL negative after PCR amplification but displayed a typical ESBL pattern with all tests.