Incidence of Metallo Betalactamases Producing Pseudomonas aeruginosa in Burn Ward of a Tertiary Care Rural Hospital

Background Prevalence of Pseudomonas aeruginosa infection is very common among indoor burn patients. Metallo-β-lactamases (MBLs) produced by clinical isolates of Pseudomonas aeruginosa has increased considerably in recent years. This may cause phenotypic resistance to virtually all clinically available β lactams. The drug resistance due to MBL has a potential for rapid spread to other micro organisms. Method A prospective study was conducted over a period of 8 months. All the Pseudomonas aeruginosa were isolated from infected burn wounds of patients admitted in burn ward. Imipenem resistant isolates were further tested by Hodge test, disk potentiation test, double disk synergy test (DDST) and MBL E test. Results Out of total 140 Pseudomonas aeruginosa isolates, 42 (30%) were imipenem resistant, among which, 20 (14.28%) were non MBL producers and 22 (15.71%) were MBL producers. MBL producers were more resistant to commonly used antibiotics than non MBL producers. All isolates were sensitive to colistin (10μg) and polymyxin B (300 μg). Conclusion Incidence of MBL producing Pseudomonas aeruginosa infection is relatively high in our set up. Simple methods for MBL production should be done routinely. Patients infected with MBL producing organisms should be promptly isolated and antibiotic stewardship programme should be made to prevent spreading of resistance.