Prevalence and antibiotic resistance pattern of metallo-beta-lactamase-producing Pseudomonas aeruginosa from burn patients--experience of an Indian tertiary care hospital.

The objective of the study is to determine the prevalence of Pseudomonas aeruginosa from burn patients, antibiotic resistance pattern and occurrence of acquired MBL-producing P. aeruginosa among isolates collected from burn patients. In this study, two phenotypic methods were used for the detection of MBL-producing P. aeruginosa: zone enhancement with EDTA-impregnated imipenem and ceftazidime discs, and modified Hodge test. One hundred fifty-four isolates of P. aeruginosa were obtained from July 2007 to July 2008. Infection was increased up to 95% in hospitalized patients for >50 days. Highest infection of 39% was found in patients, who had 41 to 50% of burn area followed by 19% in patients with 31 to 40% of burn area. The most common bacteria isolated were P. aeruginosa (55.0%), followed by Staphylococcus aureus (19.29%) and Klebsiella spp. (11.43%). Sixteen percent isolates of P. aeruginosa were positive for metallo-beta-lactamase production by both methods. Antibiotic resistance pattern of MBL-positive strains showed the highest resistance to ceftazidime (70%) followed by chloramphenicol (68%) and gentamicin (62.5%). Routine detection of MBLs ensuring optimal patient care and careful in vitro testing before antibiotic use may help in the prevention and treatment of burn patients infected with metallo-beta- lactamase-producing P. aeruginosa.