Detection of new Delhi Metallo-β-lactamase-1 (NDM-1) gene from multidrug-resistant pseudomonas aeruginosa isolated from Dhaka Medical College Hospital

Abstract

New Delhi Metallo-beta-lactamase-1 (NDM-1) producing superbugs create a global public health problem because of their resistance to most of the antibiotics. This study was conducted to determine the presence of NDM-1 producers in carbapenem-resistant Pseudomonas aeruginosa isolated from Dhaka Medical College Hospital, Bangladesh. Out of 120 gram-negative bacteria isolated from wound swab, 58 (48.33%) were Pseudomonas aeruginosa, 28 of which were from burn unit and 30 were from medicine, surgery, gynecology and obstetrics units. Pseudomonas aeruginosa isolated from burn unit showed more resistance to all other antibiotics than organism isolated from other units. Extended spectrum-β-lactamase (ESBL) producers were detected by double disk synergy test (DDS) and Metallo-β-lactamase (MBL) producers were detected by both Hodge test and double disk synergy test. Total 38 (31.67%) isolates were detected as ESBL producers and 40 (33.33%) were detected as MBL producers. In the case of Pseudomonas aeruginosa 17 (29.31%) were ESBL producers and 20 (34.48%) were MBL producers. Total 24 (41.37%) carbapenem-resistant Pseudomonas aeruginosa were detected by the disk diffusion test of which 15 were from burn unit and 9 from other units. Carbapenem-resistant Pseudomonas aeruginosa were screened for the presence of NDM-1 by PCR and 6 (25%) were found positive for blaNDM-1. In the case of the burn unit, 33.33% of carbapenem-resistant Pseudomonas aeruginosa were NDM-1 producer. NDM-1 producing Pseudomonas aeruginosa were found 100% resistant to all commonly used antibiotics except colistin. The result of this study provided insights into the high proportion of NDM-1 producers among Pseudomonas aeruginosa in Dhaka Medical College Hospital and the importance of rational use of antibiotics.