Evaluation of CHROMagarTMmSuperCARBATM as a Phenotypic Test for Detection of Carbapenemase Producing Organisms
Published: September 1, 2019 | DOI: https://doi.org/10.7860/JCDR/2019/41765.13119
Anushree Ulhas Amladi, Thambu David Sudarsanam, Subramani Kandasamy, Nitin Kekre, Balaji Veeraraghavan, Rani Diana Sahni
1. Research Officer, Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India.
2. Professor and Head, Department of Internal Medicine, Christian Medical College, Vellore, Tamil Nadu, India.
3. Professor and Head, Surgical Intensive Care Unit and Division of Critical Care, Department of Intensive Care, Christian Medical College, Vellore, Tamil Nadu, India.
4. Professor and Head Urology Unit II, Department of Urology, Christian Medical College, Vellore, Tamil Nadu, India.
5. Professor, Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India.
6. Professor, Department of Clinical Microbiology, Christian Medical College, Vellore, Tamil Nadu, India.
Correspondence
Dr. Rani Diana Sahni,
Department of Clinical Microbiology, 8th Floor, ASHA Building, Christian Medical College, Vellore, Tamil Nadu, India. E-mail: rdsahni@hotmail.com
Introduction: Carbapenem resistance among Enterobacteriaceae continues to escalate. Carbapenemase encoding genes borne on plasmids leads to wide-spread transmission among Enterobacteriaceae. The accurate and rapid detection of Carbapenemase producing-Carbapenem resistant Enterobacteriaceae (CP-CRE) is imperative for patient management as well as for hospital infection control measures. We therefore evaluated the CHROMagar™mSuperCARBA™ (CMSCs) a phenotypic screening test for detection of CP-CRE.
Aim: To evaluate the performance of CMSCs as a phenotypic test for detection of carbapenemase producing organisms.
Materials and Methods: A total of 150 consecutive Carbapenem resistant Enterobacteriaceae (CRE) (E. coli n=81 and Klebsiella spp. n=69), isolated from consecutive hospitalised patients with significant bacteriuria, were subjected to CRE Multiplex PCR for the detection of blaKPC, blaNDM, blaVIM, blaOXA-48 like and blaIMP genes. Phenotypic detection of carbapenemase production was evaluated by the chromogenic medium CMSC, CarbaNP and Modified Hodge Test (MHT).
Results: The multiplex PCR detected carbapenemase encoding gene(s) in 108 isolates. The sensitivity of CMSC, CarbaNP test and MHT in detecting isolates carrying blaNDM and blaOXA48-like genes was 94.4%, 67.6%, 56.3% and 96%, 40.8%, 38.8% respectively. While overall sensitivity of CMSC, CarbaNP test and MHT for detection of CP-CRE was 85.3%, 46.6% and 40% respectively; with a negative likelihood ratio of 0.18, 0.55 and 0.64 respectively.
Conclusion: CMSC emerged as the most sensitive test for detection of isolates carrying blaNDM and blaOXA48-like genes, with an excellent negative likelihood ratio. In addition, it was found to be inexpensive and has the fastest turnaround time. It is a promising phenotypic test especially in geographic regions with wide spread resistance due to blaNDM and blaOXA48-like CP-CRE.
[
FULL TEXT ] | [ PDF]