Genomic Analysis Identify Infecting Organisms after Joint Replacement


Thomas Jefferson University have found that genomic analysis using next generation sequencing ( NGS ), can identify infecting organisms in over 80% of cases of infected joint replacement that had previously escaped detection. The research was published in the  Journal of Bone and Joint Surgery.

Javad Parvizi senior author said, "This method can help detect pathogens that would otherwise use standard approaches, namely culture," "The study has revealed unexpected pathogens and let us select more appropriate and effective treatments for patients."

In order to test the ability to isolate infective organisms , Dr. Parvizi and colleagues prospectively enrolled patients undergoing a revision joint replacement over a 9-month period in 2016, and assessed using traditional method: culture, side by side with NGS.

The results showed that NGS identified organisms in 89% of infected cases versus 61% with culture. Furthermore, NGS was able to detect the pathogen in 81% of the cases that were negative for pathogens by the standard culture method, and which would have been missed otherwise.

One patient, whose case was described in a separate paper in  Arthroplasty,  reported to the emergency department with an infected joint replacement . Although standard culture was unable to identify the pathogen, NGS diagnostic tests resulted in an unexpected finding. 

The infection was caused by  Streptococcus canis ,  an organism found in dogs. Further questioning of the patient confirmed that he had been scratched by his dog a few days prior to the joint infection. Once the pathogen was known, the patient could be switched to more effective antibiotics and recovered well.

"The fact that we use this technology to detect organisms in culture-negative patients with an infected prosthesis may be significant, and could help provide targeted treatment for these patients," said co-author Karan Goswami. 

In addition, "However, further study is required to validate our findings in larger numbers and determine the significance of NGS signal on treatment outcomes." A multicenter trial is underway to explore this question. "

The American Academy of Microbiologists (AAM) recently published a report supporting the use of NGS, stating, "NGS has the potential to drastically revolutionize the clinical microbiological laboratory by replacing current time-consuming techniques with a single all-inclusive diagnostic test . "

Because of its promising role in diagnosing patients with periprosthetic joint infection , we have already begun to use the genomic test at our institution to isolate organisms in patients with suspected joint infection.

NGS has provided critical information for the management of cases of periprosthetic joint infection at our institution, and we work closely with our microbiology colleagues to optimize treatment for these patients