Open AccessComparative evaluation of in‐house Carba NP test with other phenotypic tests for rapid detection of carbapenem‐resistant Enterobacteriaceae
Author(s) -
Bir Raunak,
Mohapatra Sarita,
Kumar Amarjeet,
Tyagi Sonu,
Sood Seema,
Das Bimal Ku,
Kapil Arti
Publication year - 2019
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.22652
Subject(s) - citrobacter freundii , enterobacter cloacae , enterobacteriaceae , klebsiella pneumoniae , microbiology and biotechnology , enterobacter , carbapenem , biology , agar , escherichia coli , citrobacter , enterobacteriaceae infections , bacteria , gene , antibiotics , genetics
Background The prevalence of carbapenem‐resistant Enterobacteriaceae ( CRE ) is alarming worldwide causing serious infections. Rapid and accurate identification of CRE is crucial to reduce the mortality and morbidity. In this study, we tried to develop an in‐house Carba NP test for detection of CRE and evaluate its performance with others. Methods A prospective study was conducted with 40 nonrepeating Enterobacteriaceae isolates over a period of 3 months. All the isolates were screened for carbapenem resistance as per CLSI 2016 guidelines followed by PCR for bla NDM ‐1, bla OXA ‐48, bla KPC , bla VIM , and bla IMP genes. All the isolates were subjected to five phenotypic tests, that is, in‐house Carba NP ( iC arba NP ), commercial Carba NP ( cC arba NP ), Blue‐Carba, modified Hodge test ( MHT ), and CHROMagar. Results Among the 40 isolates, 87.5% were identified as Escherichia coli , 7.5% were Klebsiella pneumoniae , 2.5% were Enterobacter cloacae , and 2.5% were Citrobacter freundii . Thirty‐three of 40 (82.5%) isolates were found to harbor one or more resistant genes. Considering PCR to be the gold standard test, sensitivity of the phenotypic methods for CRE detection ranged from 63.6% ( MHT ) to 96.9% ( CHROM agar). Both cC arba NP and iC arba NP observed to have highest specificity. The performance of iC arba NP was found comparable with cC arba NP by kappa score 1 and found approximately 10 times less expensive than cC arba NP. Conclusion CHROM agar was observed most sensitive assay for detection of CRE followed by both Carba NP tests. iC arba NP was proved cheaper and equally good as cC arba NP for detection of CRE.