Methods and early findings from a study comparing next-generation sequencing versus traditional cultures for penile implants concerning for low-grade infection

Microbial culture is the current standard of care to choose therapeutic antibiotics for infection occurring with inflatable penile prostheses (IPPs). However, next-generation sequencing (NGS) of DNA has proven beneficial for analysis of biofilm composition and relative abundance of specific microorganisms. The main goal of this study is to evaluate whether NGS compared to microbial culture can better guide the management and antibiotic selection and device survival rates. We hypothesize that identifying microbial composition with NGS, as compared with traditional culture, will lead to better therapeutic strategies resulting in improved patient outcomes and device survival. In this present manuscript, we describe the overall study methodology and analyze device survival rates, classify clinical presentations of IPP infections, and determine infected implant microbial composition and antibiotic resistance among an early patient cohort. These early results included 18- to 80-year-old consecutive male patients who received antimicrobial treatment without surgical replacement for at least 7 days since identification of infected IPPs. Subjects were randomized into two analytic arms: traditional culture and NGS. Throughout the study, investigators and patients completed questionnaires to provide data for comparison. To date, of the 9 patients enrolled in the study, 6 eventually underwent device removal due to worsening infection within 7 days of initiating empiric antibiotic treatment. Six patients were seen in a clinic setting, while 3 were seen in the hospital/emergency department: 7 implants were primary, while 2 were secondary. All subjects received a Coloplast IPP but had differing reservoirs and reservoir locations. In cases where penile shaft tenderness was present, the implanted IPP was more often removed within 7 days. In contrast, when no tenderness was reported, the device remained viable for at least 10 days. As of this report, 11 active sites have participated in the study, with ongoing patient enrollment aimed at reaching sufficient sample sizes for statistical comparison. Penile shaft tenderness was a common presentation among patients whose early antibiotic treatment for IPP infection failed. Recruitment of additional patients to this prospective, randomized controlled trial will help to identify favorable presentations of IPP infection. Additional data will allow comparison of implantation outcomes between NGS and traditional culture.