Microbiological profile and antimicrobial susceptibility pattern in orthopaedic implant associated infections

Postoperative wound infection is a serious complication in presence of prosthetic implantation (infectivity rate 10.4%). Implant infection is particularly high in developing countries. Hence there is a need to know the clinical presentation, common organisms and their susceptibility pattern in a particular region.

The patients who had undergone orthopaedic prosthesis or implant surgeries and presented with signs and symptoms of infection were included in this study. Pus, tissue, fluid samples obtained were streaked in Blood agar and MacConkey agar plates and incubated at 37°C, two Sabouraud Dextrose agar slants incubated at 28°C and 37°C and Gram staining and Acid-fast staining performed. Antimicrobial susceptibility testing was performed for all bacterial isolates. Data collection was done using a proforma and analysis of data was done and expressed as frequency and percentage.

A total of 149 samples obtained from patients with Orthopaedic implant associated infections were processed. Of these 131 (87.9%) were culture positive. Staphylococcus aureus was the most common pathogen, followed by Pseudomonas spp. Escherichia coli and Staphylococcus other than S. aureus. Ten (7.6%) cases had multiple organisms and 2 fungi were also isolated (1.5%). Among the S. aureus, MSSA was the commonest and 42 (30.2%) isolates were multidrug resistant organisms.

Infection is the major cause of delayed healing in patients with Orthopaedic implants. Early identification and aggressive treatment with the appropriate antibiotics are necessary to decrease infection rate, reduce hospital stay, prevent biofilm formation, decrease the need for Implant removal or replacement, and prevent disability in the patients.