Evaluation of two types of swabs for sampling allograft musculoskeletal tissue

Abstract Background Allograft musculoskeletal tissue is commonly sampled by a swab for bioburden screening. To determine if bioburden recovery could be improved at the pre‐analytical stage, two swab systems were evaluated: the A mies gel swab and the E Swab. Methods In vitro studies were performed to determine the recovery of each swab system with <100 colony‐forming unit of challenge organisms using inoculated swabs and by sampling inoculated femoral heads. The standard culture protocol used in this laboratory was also evaluated after sampling of inoculated femoral heads. A prospective study was performed with both swab systems used in parallel to sample cadaveric allograft musculoskeletal tissue. Results The challenge organisms could be recovered from the in vitro inoculated studies. The standard culture protocol in this laboratory recovered all challenge organisms from both swab systems. One hundred and six paired A mies and ES wabs were collected from eight cadaveric donors with skin commensals the predominant isolates. Conclusions The sampling of an inoculated femoral head was included to reflect routine swab sampling practice as was the inclusion of the standard method used in this laboratory. This appears to be the first study to compare A mies gel swabs with ES wabs to sample allograft femoral heads and in a prospective study with cadaveric allograft musculoskeletal tissue. Other comparative studies of swab systems have used a much higher inoculum to mimic an infection; however, sepsis is an exclusion criterion for allograft donors. It was found that the A mies gel swab and ES wab are both suitable sampling devices for bioburden testing of allograft musculoskeletal tissue.