Molecular testing with next-generation sequencing appears to identify biofilm on penile prostheses better than traditional cultures: The new gold standard?
Traditional culture is the current standard-of-care to determine therapeutic antibiotics for patients suffering from penile prostheses (PP) infections. However, approximately 50% of PPs removed for infection are culture negative. Next-generation sequencing (NGS) compares DNA sequences to reference sequences with known microbial taxonomies to identify isolates and report relative abundances. We aim to compare the ability for standard culture and NGS techniques to identify microorganisms and biofilm composition on PPs.
Materials and methods:
Ninety-one PPs explanted for mechanical malfunction were included in this study. Devices removed for infection or erosion were excluded. During revision surgery, two specimens were collected and sent for culture testing at institutional laboratory and for NGS testing (MicroGenDx, Lubbock, TX, USA). Species’ relative abundances, sample diversity and richness, and compositional differences among samples were analyzed.
Results:
NGS had a higher rate of microbial detection (n = 72, 79.1%) compared to culture results (n = 3, 3.3%). Some of the bacteria identified using both methods were known prosthetic infectious pathogens, with NGS producing more isolates (mean: 11) than culture (mean: 1). Escherichia coli was the most abundant and most frequently occurring bacteria detected on NGS. Coagulase-negative Staphylococci were the most common bacteria detected on traditional culture.
Conclusions:
NGS appears to be beneficial in its thorough analysis of PP biofilm composition when compared to culture methods. We hope that further research will be able to demonstrate a clinical benefit of NGS in characterizing distinct microbiomes and biofilms of infected PP, which can aid in tailoring antimicrobial therapy and improving patient outcomes.