Prevalence and Antimicrobial Susceptibility Profile of Metallo-<i>β</i>-Lactamase Producing <i>Pseudomonas aeruginosa</i> Isolates at Kenyatta National Hospital

Abstract

Pseudomonas aeruginosa is a major cause of nosocomial infections with high mortality rates. The organism is highly resistant to most classes of drugs used and can develop resistance during treatment. One of the resistance mechanisms of P. aeruginosais is Metallo- β -Lactamase (MBL) production. MBL producing P. aeruginosa is a major health concern given it’s resistance to almost all available drugs. The prevalence of this resistant strain is unknown since there is no standardized method for testing MBL production. This was a laboratory based cross-sectional prospective study that was carried out from September 2015 to March 2016 at Kenyatta National Hospital. Ninety-nine isolates of P. aeruginosa were collected during the period and tested for antimicrobial susceptibility and isolates found to be resistant to imipenem tested for MBL production. The results indicated high resistance of P. aeruginosa to commonly used drugs. Of the isolates tested 69.7% were resistant to piperacillin, 63.6% were resistant to aztreonam, 58.6% were resistant to levofloxacin, 55.6% were resistant to cefipime, 65.7% were resistant to ceftazidime, 68.7% were resistant to ticarcillin-clavulanate, 72.2% were resistant to meropenem, 64.9% were resistance to imipenem while 86.4% of urine isolates were resistant to ofloxacin. Of the isolates resistant to imipenem 87.3% were found to be MBL producers. In conclusion, P. aeruginosais highly resistant to the drugs currently is used for treatment and resistance to carbapenems is largely due to MBL production.