Ureaplasma parvum Prosthetic Joint Infection Detected by PCR

We describe the first reported case ofUreaplasma parvum prosthetic joint infection (PJI) detected by PCR.Ureaplasma species do not possess a cell wall and are usually associated with colonization and infection of mucosal surfaces (not prosthetic material).U. parvum is a relatively new species name for certain serovars ofUreaplasma urealyticum , and PCR is useful for species determination. Our patient presented with late infection of his right total knee arthroplasty. Intraoperative fluid and tissue cultures and pre- and postoperative synovial fluid cultures were all negative. To discern the pathogen, we employed PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). Our patient's failure to respond to empirical antimicrobial treatment and our previous experience with PCR/ESI-MS in culture-negative cases of infection prompted us to use this approach over other diagnostic modalities. PCR/ESI-MS detectedU. parvum in all samples.U. parvum -specific PCR testing was performed on all synovial fluid samples to confirm theU. parvum detection.