title: Approach to Carbapenemase Detection inKlebsiella pneumoniaein Routine Diagnostic Laboratories.
abstract: BACKGROUND
  Resistance to Carbapenems inKlebsiellamay be due to Carbapenem hydrolysing enzymes. Accurate detection of carbapenemase must be done for patient treatment and epidemiological purposes.
  
  
  OBJECTIVE
  To detect carbapenemase production by performing Modified Hodge Test (MHT), Combined Disk Test (CDT) for Metallo-β-Lactamases (MBL) and PCR for blaKPCgene, to evaluate the performance of MHT using MacConkey Agar (MCA) and to access the value of MHT for carbapenemase detection.
  
  
  METHODS
  Using a prospective laboratory study design, 153 Extended Spectrum Beta-Lactamases (ESBL) producingKlebsiella pneumoniaefrom clinical samples of patients admitted in the Kasturba Medical College were collected from January 2014 to December 2015. Isolates resistant to carbapenems by disk diffusion were subjected to MHT on MCA and Mueller Hinton agar (MHA). All isolates were tested for (MBL) production by Imipenem and Imipenem-EDTA CDT and subjected to PCR for the presence of blaKPCgene.
  
  
  RESULTS
  Out of 153 isolates, 54 were resistant to one of the carbapenems. Among these, 13 were positive for MHT on MHA, while 23 were positive by MHT on MCA. Number of MBL producers was 23 (42.5%), while blaKPCwas detected in 2 out of the 54 isolates.
  
  
  CONCLUSIONS
  Though detection of drug resistance gene remains the method of choice, it can be performed only in centers with adequate resources. Hence, for most laboratories in resource poor countries, the MHT performed on MCA with concomitant CDT for MBL detection seem to be a better option for detection of Carbapenem resistance.
authors.affiliation: Tutor, Department of Microbiology, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Rangnekar
authors.initials: R
authors.lastname: Aseem
authors.affiliation: Professor, Department of Microbiology, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Shalini
authors.initials: S
authors.lastname: Shenoy
authors.affiliation: Associate Professor, Department of Microbiology, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Suchitra Shenoy
authors.initials: SS
authors.lastname: Mala
authors.affiliation: Professor, Department of Microbiology, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Shrikala
authors.initials: S
authors.lastname: Baliga
authors.affiliation: Tutor, Department of Biochemistry, Kasturba Medical College, Manipal University , Mangalore, Karnataka, India .
authors.forename: Agarwal
authors.initials: A
authors.lastname: Ashish
keywords: Carbapenems; Extended spectrum beta-lactamases; Metallo-β-lactamase; Modified hodge test