CARBA NP a Rapid and Reliable Test for Detection of Carbapenemases in Gram Negative Bacteria

Both molecular and non-molecular tests currently employed for the detection of carbapenemases are costly, time-consuming and are poorly adapted to the clinical need for isolating patients rapidly to prevent health care associated outbreaks. The present study was thus conducted for rapid detection of carbapenemases in clinical isolates of Gram negative bacteria by Carba NP test. A total of 270 Gram-negative bacilli included were divided into three groups Group I (n=100): Gram negative bacteria isolated from routine samples. Group II (n=130): Imipenem resistant Gram negative bacteria. Group III (n=40): Twenty PCR confirmed for bla VIM and bla NDM1 and twenty PCR negative for bla VIM and bla NDM1 isolates. These isolates were subjected to Carba NP test. Antimicrobial susceptibility was performed by Kirby Bauer disk diffusion method. Out of 100 isolate (Group I), 32 were positive and out of 130 imipenem resistant (Group II), 112 isolates were positive for carbapenemase production by carba NP test. The sensitivity and specificity was 100% for Carba NP test. This test is rapid, user-friendly and does not require costly equipment hence is suitable for resource poor settings. Rapid detection of carbapenemase by this test and timely institution of infection control measures will help in preventing spread of infection.