Suraj Giri1, Sourav Sen2, Mahima Lall3
BACKGROUND
In an infection caused by multidrug-resistant Enterobacteriaceae, carbapenems is
one the last antibiotics used, but the carbapenemase producing
Enterobacteriaceae pose a clinical challenge. A relatively new test which was
described few years back known as modified carbapenem inactivation method
(mCIM) is used to detect the presence of carbapenemase activity in Gramnegative
bacilli. Various studies show this test be to be very sensitive and specific.
We aim to study mCIM positivity on samples which are positive by Kirby-Bauer
disk diffusion antibiotic sensitivity test method used for detection of carbapenem
resistant Enterobacteriaceae (CRE) from clinical specimens.
METHODS
The study is a cross sectional descriptive study conducted in a tertiary care
hospital. Samples received from February 2019 to September 2019 were included
in the study. During this period 150 samples were collected which were resistant
to meropenem by Kirby-Bauer disk diffusion method. These CREs isolates were
further subjected to mCIM and the result was analysed.
RESULTS
Out of the total 150 CRE isolates which were 100 % resistant to meropenem by
the conventional disc diffusion method it is found that mCIM was positive for 148
(98.66 %) isolates and negative for only 02 (1.33 %). Two most common CRE
were Klebsiella pneumonia (58 %) and Escherichia coli (32 %). In statistical
analysis chi square test revealed statistically significant difference (P < 0.05) in
percentage of positivity between the two methods (98.66 % vs 100 %).
CONCLUSIONS
mCIM is highly sensitive and specific method; however, in practice it showed no
added advantage over Kirby-Bauer disk diffusion method in detecting CRE.
