Abstract
Background: Carbapenem-resistant Enterobacteriaceae (CRE) are increasingly being reported throughout the world, which is a significant problem for patient treatment and infection control. Carbapenem-resistance in Enterobacteriaceae is mainly due to carbapenemhydrolyzing β-lactamase, which tends to spread through genetic mobile elements. Therefore, the detection of carbapenemase-producing Enterobacteriaceae (CPE) carriers is particularly important for the prevention and epidemiological monitoring of these infections. In this study, we performed surveillance cultures for CPE in patients admitted to the hospital and evaluated the prevalence of CPEMethods:Stool cultures were obtained from a total of 228 patients at our tertiary-care hospital between March and May 2017. Stool specimens were inoculated on ChromID CARBA agar (bioMérieux, France) and incubated for 18-24 hours. Suspicious colonies with pink or bluish-green color were screened for CPE by the modified Hodge test (MHT) and carbapenemase inhibition test (CIT). We performed PCR to detect five carbapenemase genes, blaKPC, blaIMP, blaVIM, blaNDM, and blaOXA-48.Results: Among 228 isolates, seven were suspicious for CPE: four Klebsiella pneumoniae, one Escherichia coli, one Enterobacter aerogenes, and one Serratia marcescens. Two K. pneumoniae isolates showed positive reactions in both the modified Hodge test and inhibition test with phenylboronic acid. By PCR, blaKPC was identified in these two K. pneumoniae isolates.Conclusion: Our results showed a very low prevalence (2/228, 0.9%) of CPE in our tertiary-care hospital based on surveillance culture in a recent three month period. (Ann Clin Microbiol 2018;21:8-11)
Keywords
Carbapenemase-producing Enterobacteriaceae Healthcare-associated infection Infection control
Acknowledgements
This work was supported by the research fund of Hanyang University (HY-2016-2782).
Figures & Tables
Table 1. Isolates suspicious for carbapenemase-producing
| No. of isolate | Sex/age | Species | Colony | Modified Hodge test | Inhibition test (zone diameter, mm) | CPE gene | ||
| MEM | PBA | EDTA | ||||||
| 1 | M/71 | Green | − | 13 | 22 (+) | 17 (+) | ND | |
| 2 | F/73 | Green | − | 21 | 24 (w+)* | 22 (−) | ND | |
| 3 | M/37 | Green | + | 14 | 22 (+) | 16 (−) | ||
| 4 | F/80 | Green | + | 14 | 22 (+) | 14 (−) | ||
| 5 | M/84 | Pink | − | 26 | 27 (−) | 27 (−) | ND | |
| 6 | M/68 | Green | − | 21 | 23 (−) | 22 (−) | ND | |
| 7 | M/74 | Green | − | 27 | 28 (−) | 28 (−) | ND |
