Imipenem Resistance Mechanisms in Multidrug Resistant Pseudomonas aeruginosa clinical isolates from south India

This study reports the resistance profiles of 45 P. aeruginosa isolates from 85 burn patients (52.94%). Among them, 27(60%) of the isolates showed multidrug resistance to more than eight antibiotics and 14 (30%) isolates were found to be imipenem resistant (IMRPA). All the 45 P. aeruginosa strains screened showed resistance to ciprofloxacin, ceftazidime, cefepime and piperacillin, 96% gentamycin, 44% to tobramycin, 25% amikacin and 40% aztreonam. However, low range of resistance was observed to imipenem 30%, ticarcillin (20%) colistin (12%) and polymyxin B 14%. Genotype examination revealed that the multidrug isolates produced the integron located integrase gene-specific (int13) and acc(6')-1b genespecific primers found to be well conserved among blan4P-positive strains. The P. aeruginosa isolates were separated into two genotypes: genotype A had high prevalence (12 strains) than genotype B (3 strains). Routine detection of metallo beta lactamase in vitro testing along with antibiotic use may help in prevention and treatment of burn patients infected with metallo beta lactamase producing P. aeruginosa.