Emergence of Hospital Acquired Carbapenem Resistant Non-Fermenters in Teaching Institute

Abstract

Introduction: Non-Fermenting Gram Negative Bacilli (NFGNB) are emerging now-a-days because of their tendency to colonize various surfaces and inherent resistance to commonly used disinfectants. They are responsible for multi-drug resistant hospital acquired infections. Detection of carbapenem resistance mechanisms is essential for treatment and infection control purpose as can spread to other organisms causing hospital outbreaks. Aim: To characterize non-fermenters from various clinical samples and to detect different carbapenem resistance mechanisms in meropenem resistant isolates. Materials and Methods: The prospective study was conducted at Sri Aurobindo Medical College and Post Graduate Institute, Indore over a period of one and half year from December 2014 to May 2016. A total of 1310 samples were collected from Ventilator Associated Pneumonia (VAP), Surgical Site Infection (SSI), Urinary Tract Infection (UTI), septicaemia, Lower Respiratory Tract Infection (LRTI) and middle ear infected patients. Nonfermenters were identified by standard microbiological tests. Meropenem resistance was determined by Kirby-Bauer disk diffusion method and resistant isolates were further tested by Modified Hodge test, Combined disc test and AmpC disc test. Results: Isolation rate of non-fermenters was 13.82% (181/1310). Colistin, amikacin and imipenem were the antibiotics with maximum sensitivity. Overall meropenem resistance was found to be 44.2% (80/181). Metallo-β-lactamase and AmpCβ-lactamase were produced by 56.82% (25/44) and 72.22% (26/36) of meropenem resistant Pseudomonas and Acinetobacter species respectively. Conclusion: Detection of carbapenem resistance mechanisms and implementation of antibiotic policy are needed to prevent the emergence of non-fermenter infections.

Keywords

• combined disc test
• ampc disc test
• modified hodge test