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>7 d 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.