Non-infected penile prosthesis cultures during revision surgery; comparison between antibiotic coated and non - coated devices

Abstract

Introduction:Aim of this study is to investigate bacterial growth on non-infected devices and compare antibiotic-coated and non-coated implants.Materials and methods:The charts of 71 patients who underwent revision surgeries for penile prosthesis between 1995 and 2013 were reviewed. Of those, 31 devices were antibiotic-coated prostheses, while 40 of the implants were non-coated. Swab cultures were routinely obtained from corporal, pump or reservoir site during the operation. If a bacterial biofilm was determined on the prosthesis, it was also cultured.Results:A total of 5 different organisms were cultured from 18 patients. Of them, 4 devices were antibiotic-coated and the other 14 were non-coated devices. Staphylococcus epidermidis was the most common organism, while Staphylococcus hominis, beta hemolitic streptococcus, Escherichia coli and Proteus mirabilis were also cultured. All patients who had positive cultures were treated with appropriate antibiotics for four weeks postoperatively. Median follow-up time was 41 months, ranging between 8 and 82 months. One prosthesis (non-coated) became clinically infected in the follow-up period with a totally different organism. Culture positivity rates of antibiotic-coated and non-coated devices were 13% and 35% respectively and the result was significant (p=0.00254).Conclusions:Positive bacterial cultures are present on non-infected penile prostheses at revision surgeries in some of the patients. Antibiotic coated prostheses have much less positive cultures than non-coated devices.

A scoping review of penile implant biofilms—what do we know and what remains unknown?

“…The first study describing biofilms on PP was published Records identified through PubMed MEDLINE database searching "penile prosthetic" OR "penile prosthesis" OR "penile implant" AND "biofilm" OR "revision" OR "removal" OR "infection" OR "explant" (n=3,171) (14).…”

“…Subsequently in 2006, Silverstein et al described the presence of bacteria on laser microscopy among eight of ten non-antibiotic coated-PP explanted for mechanical function, seven of which had biofilm (13). Ciftci et al also specifically identified biofilm in two of 18 non-infected implants who had a positive culture; both of these biofilms grew S. epidermidis (14). Most recently, Chung et al also identified biofilm on both standard culture and nextgeneration sequencing (NGS) in 24 and 48 of 83 samples, respectively (36).…”

“…Even more recently, a study using NGS found that P. aeruginosa and E. coli were the most frequent and abundant organisms encountered in their cohort of infected and mechanically malfunctioned patients, respectively (36). Some reports have also demonstrated a discrepancy in the culture data between the first revision surgery for non-infectious reasons when compared to the second revision for infectious etiologies (14). Of 202 revision surgeries for infection reported by Chandrapal et al, they found that only 22% of implants grew the same organisms at explantation for infection when compared to their original swabs at first revision (39).…”

Penile implant infection prevention part II: device coatings have changed the game

“…compared swab cultures of coated and noncoated devices at revision surgery for reasons other than infection. They noted that the bacterial growth was significantly less on coated implants at revision surgery than noncoated ones [16]. The overriding question of all experts is, "if every implant is contaminated with bacterial growth protected by biofilm, why do so few devices actually present with a clinical infection?"…”

“…The new and very tough targets, the toxic bacteria, may require other measures for infection prevention. After all, during in vitro studies of zones of inhibition created by strips of implant surfaces coated with the infection retardants, the toxic bacteria were quite resistant to the dosage of the dispersed antimicrobials [1,16,18,22].…”