The Role of MDR-Acinetobacter baumannii in Orthopedic Surgical Site Infections

Background: Gram-positive microorganisms were the main causative organisms of orthopedic surgical site infections (SSI); however the rising incidence of multiple drug resistant Acinetobacter baumannii (MDR-AB) infections in orthopedic operations causes a great concern because of their limited array of therapeutic options. Objective: Our objective was to remark the changing microbiology in orthopedic SSI and to evaluate the MDR CHROMagar Acinetobacter media for screening of MDR-AB. Methods: Aspirated pus samples were collected from infected wounds of 100 patients in the orthopedics unit of El-Helal Hospital, samples were cultured on conventional media and MDR CHROMagar Acinetobacter media, the reveled MDR-AB colonies were subjected to polymerase chain reaction (PCR) to detect blaOXA-51 like gene. Results: Out of 100 infected wounds SSI cases represented 90/100 (90%) according to CDC 2013 definitions. Staphylococcus aureus was the dominant organism 40/90 (44.4%) (P value 0.038), all S. aureus isolates were methicillin-resistant Staphylococcus aureus (MRSA), followed by Klebsiella pneumoniae 22/90 (24.44%) and Acinetobacter 15/90 (16.67%). Implant was highly associated with SSI cases 80/90 (89%). Also, prolonged hospital stay >7d was significantly associated with SSI 69/90 (77%) (p=0.001). Conclusion: Staphylococcus aureus was the main causative organism of orthopedic SSI (44.4%), whereas A. baumannii represented only (16.67%) of the causative organisms. MDR Acinetobacter CHROMagar reduced the turnaround time for screening of MDR-AB.