Improved diagnosis of orthopedic implant-associated infection by inoculation of sonication fluid into blood culture bottles.
Sonication improved the diagnosis of orthopedic implant-associated infections (OIAI). We investigated the diagnostic performance of sonication fluid inoculated into blood culture bottles in comparison with that of intraoperative tissue and sonication fluid cultures. Consecutive patients with removed orthopedic hardware were prospectively included and classified as having OIAI or aseptic failure (AF) according to standardized criteria. The diagnostic procedure included the collection of five intraoperative tissue cultures and sonication of the removed device, followed by conventional culture of the sonication fluid. Cultures were incubated for 7 days (aerobic) or 14 days (anaerobic). In addition, 10 ml of sonication fluid was inoculated into each aerobic and anaerobic BacT/Alert FAN blood culture bottle and incubated in the automated blood culture system for 5 days. Of 75 included patients, 39 had OIAI and 36 AF. The sensitivity of sonication fluid inoculated into blood culture bottles (100%) was higher than that of conventional sonication fluid (87%; P = 0.05) or intraoperative tissue cultures (59%; P < 0.01). Previous antibiotic therapy reduced the culture sensitivity of conventional sonication fluid to 77% and that of intraoperative tissue to 55%, while it remained 100% for blood culture-inoculated sonication fluid. The time to positivity was shorter in blood culture-inoculated sonication fluid, with detection of 72% of microorganisms after 1 day of incubation, than for intraoperative tissue and conventional sonication fluid cultures, with detection of 18% and 28% of microorganisms, respectively. In conclusion, compared to conventional sonication fluid and intraoperative tissue cultures, sonication fluid inoculated into blood culture bottles improved the diagnosis of OIAI and considerably reduced the time to culture positivity.
Microbiology Laboratory, Reference Laboratory of Catalunya, Barcelona, Spain Center for Septic Surgery, Charité-University Medicine Berlin, Berlin, Germany portillobordonabe@gmail.com.
María Eugenia
ME
Portillo
Microbiology Laboratory, Reference Laboratory of Catalunya, Barcelona, Spain.
Margarita
M
Salvadó
Center for Septic Surgery, Charité-University Medicine Berlin, Berlin, Germany.
Andrej
A
Trampuz
Microbiology Laboratory, Reference Laboratory of Catalunya, Barcelona, Spain.
Ana
A
Siverio
Department of Orthopedic Surgery, Hospital del Mar, Barcelona, Spain.
Albert
A
Alier
Infectious Diseases, Hospital del Mar, Research Institute (IMIM), Barcelona, Spain.
Lluisa
L
Sorli
Department of Orthopedic Surgery, Hospital del Mar, Barcelona, Spain.
Santos
S
Martínez
Department of Orthopedic Surgery, Hospital del Mar, Barcelona, Spain.
Daniel
D
Pérez-Prieto
Infectious Diseases, Hospital del Mar, Research Institute (IMIM), Barcelona, Spain.
Juan P
JP
Horcajada
Department of Orthopedic Surgery, Hospital del Mar, Barcelona, Spain.
Lluis
L
Puig-Verdie
D000328:Adult; D000332:Aerobiosis; D000368:Aged; D000369:Aged, 80 and over; D000693:Anaerobiosis; D005260:Female; D006801:Humans; D008297:Male; D008828:Microbiological Techniques / Q000379:methods*; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects; D019736:Prostheses and Implants / Q000382:microbiology*; D016459:Prosthesis-Related Infections / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013010:Sonication; D013048:Specimen Handling / Q000379:methods*; D013997:Time Factors