To explore the microbiology and antibiotic susceptibility of bacteria isolated from infected joint after total hip arthroplasty and total knee arthroplasty and assess the antibiotic treatment options for prosthetic joint infection.

The microbiology, antimicrobial susceptibility and antibiotic treatment data of prosthetic hip and knee infection patients in West China Hospital between January 1, 2010 and December 31, 2015 were retrospective reviewed and analyzed.

A total of 146 patients were identified, 111 cases were prosthetic hip infection and 35 cases were prosthetic knee infection, and the prevalence of culture negative was 26.03%. Gram-positive bacteria were the main pathogen, encountered 55.48%. The most common organisms were staphylococcus epidermidis (25.34%) and staphylococcus aureus (15.07%). Gram-negative isolates encountered 13.01%, and Escherichia coli (6.85%) was the most common causative organism, followed by enterobacter cloacae (4.79%) and pseudomonas aereginasa (3.42%). The results of antibiotic susceptibility showed gentamicin, clindamycin, beta-lactanm antibiotics were poorly susceptibe to gram-positive isolates, but they were sensitive to antibiotic such as rifampin, linezolid, furantoin, quinupristin and vancomycin. Antibiotic such as amikacin and imipenem were sentive to Gram-negative bacteria, but gentamicin, tobramycin and cephalosporins had high resistance rate. Empirical antibiotic treatment should combined vancomycin and ceftriaxone, fluroquinolone or clindamycin. When the pathogen was confirmed, the treatment should be individualized.

The prevalence of culture negative was still very high. The dominate pathogen was Gram-positive bacteria, and the most common organisms were Staphylococcus Epidermidis and Staphylococcus Aureus. The empirical antibiotic should cover the Gram-positive isolate, especially the staphyloccus. When the pathogen was confirmed, the treatment should be individualized, taking into account the infection organism and results of antibiotic susceptibility.