Multi-drug Resistant Bacterial Isolates Associated with Blood Stream Infection

Multidrug resistant (MDR) bacteria complicate therapeutic management and limit treatment options. With the increase of antibiotic resistance among bacterial isolates, monitoring of the of drug resistance pattern became critical for appropriate empiric selection of antibiotic therapy. Between June 2014 to January 2015, a prospective study was carried out in Manmohan Memorial Medical College and Teaching Hospital, Kathmandu with an objective to determine the status of Extended Spectrum Beta- Lactamase (ESBL) and Biofilm producing MDR bacterial isolates from blood samples. Identification of the isolates was done by standard microbiological techniques and antibiotic susceptibility testing was done by Kirby Bauer disc diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines. ESBL screening of gram negative isolates was done using Ceftriaxone, Aztreonam, Cefotaxime, Ceftazidime and Cefpodoxime followed by confirmation using MASTDISCSTM Extended Spectrum Beta- Lactamase (ES?L) Detection Discs and Biofilm detection was done by Congo-Red and Tube- adherence Method. The culture positivity of 16% and 10 different species of bacteria were isolated. The most frequently occurring isolate was Escherichia coli followed by Staphylococcus aureus. In vitro antibiotic susceptibility test showed that Amikacin remains the principle antibiotic of choice based on its effectiveness on both gram positive and gram negative bacteria.Ninety five percent of isolates were MDR with 77.19% ESBL producers and 72.5% were biofilm producers. A statistically significant relationship was found between increasing spectrum of drug resistance and ESBL production and drug resistant in biofilm production (p<0.05)