Imipenem resistant Metallo –Beta-lactamase producing Pseudomonas aeruginosa (IR-MBLP-PA) are an  emerging threat causing noscomial infections with increased mortality and morbidity and with a potential to spread rapidly and  cause outbreaks and epidemics. Very little data is available after review of literature  on detection of IR-MBLP-PA  from hospital environmental  sources  and their role as source and/or reservoir of nosocomial infections. The present study was conducted to  detect  IR-MBLP-PA from different  hospital environmental sources from different areas of hospital, Antibiogram typing, to assess their role as source and /or reservoir of nosocomial infections and study the impact of infection control measures on environmental sources of IR-MBLP-PA. 460 environmental specimens collected and processed by standard laboratory procedures. Susceptibility testing done by Kirby-Bauer’s disc diffusion method. IR-MBLP-PA detection  was done by IMIPENEM+EDTA combined disc test. Antibiogram typing done. Association with clinical cases done by strain of same antibiogram type  from environmental source and case. Impact of Infection control measures were  assessed by percentage reduction of IR-MBLP-PA isolates from respective environmental sources.

Study reported an incidence of 24.78 %;5.65 % and 3.48%;1.08% for Pseudomonas aeruginosa and IR-MBLP-PA respectively, before and after strict infection control measures. High incidence of IR-MBLP-PA of 14.8% and 10.52% in suction apparatus and mops respectively, 11.53%, 8.89% and 8.24% in Burns ward, ICCU and MICU respectively was reported. Six of the eight IR-MBLP-PA antibiogram types from environmental sources could be associated with fourteen nosocomial infections with two strains with no association. Strain 1 (Resistant to all antibiotics used) was most common strain (30.76%)  associated with six nosocomial infections during the study period. Sinks, suction apparatus were  observed to be high risk  sources and/or reservoirs of IR-MBLP-PA. MICU and ICCU were found to be  high risk areas of environmental isolates necessitating periodic environmental sampling for their detection.  Hospital air, aprons and gowns of health care workers, curtains, beddings and linen  were not found to be important reservoirs of IR-MBLP-PA. Infection control measures according to CDC guidelines reduced the incidence of environmental IR-MBLP-PA isolates.