ABSTRACT
Introduction: Surgical site infections are associated withpatient morbidity, longer duration of hospital stay and excesshospital costs. Study objective was to determine frequency ofvarious micro-organisms isolated from surgical site infectionsand their Antibiogram in Cardiac surgery unit.Material and methods: This study was conducted atpathology laboratory of Punjab Institute of Cardiology,Lahore for a period of 10 months from May 2017 to February2018. A total of 200 pus samples were collected from patientssuffering from Surgical Site Infections. Samples were culturedon MacConkey agar and Chocolate agar and were incubatedat 37°C for 24hrs. Organisms were identified on the basis ofcolonial morphology, Gram staining and biochemical tests.Antimicrobial sensitivity testing was performed on MullerHinton agar by using modified Kirby-Bauer disc diffusiontechnique and E-strips.Results: Out of 200 cultures, bacterial growth was obtainedfrom 43%. Among total isolates, 58% were Gram positive and42% were Gram negative bacteria. Most frequently isolatedorganism from wound swabs was Staphylococcus aureus(41.9%) followed by Coagulase negative Staphylococcus(14%). Gram negative bacteria isolated were Klebsiella from10%, Enterobacter from 10%, E.coli from 8%, Acinetobacterfrom 4% and Pseudomonas aeruginosa from 4% of surgicalwounds. All Gram Positive organisms were resistant toPenicillin, 80% to Erythromycin, 64% to Ciprofloxacin,64% to Methicillin and 28% Amikacin. All were susceptibleto Vancomycin and Linezolid. In case of Gram negativeorganisms, all isolates were resistant to Ampicillin, 94.5%to Ceftriaxone, 83.3% to Cefepime, 83.3% to Aztreonam,72.2% to Amoxycillin/clavulanate, 50% to Ciprofloxacin,44.5% to Pipperacillin-Tazobactam, 33% to Amikacin, 33.3%to Cefoperazone-sulbactam and 27.8% were resistant toImipenemConclusion: Gram positive pathogens were most commoncause of surgical site infection in cardiac surgery patients.However, significant proportion of infections were caused byGram negative pathogens.