Evaluating ATP Bioluminescence Testing for Microbial Surveillance of Materials and Solutions Used in the Routine Cleaning of Cranial Implant Chambers in Rhesus Macaques (Macaca mulatta)

Nonhuman primates with long-term cranial implant chambers require regular chamber cleaning with antiseptic solutions. The purpose of this study was to determine if ATP bioluminescence testing can be used to identify microbial contamination of fomites and environmental samples in the context of cranial implant chamber cleaning procedures. ATP bioluminescent swab samples were compared with traditional bacterial culture swab samples from the same sources collected during the scheduled chamber maintenance procedures for Rhesus macaques ( Macaca mulatta ) that are part of studies related to the modulation of brain circuits in parkinsonism. Over the course of 17 d, samples were collected from the chamber rims, forceps (pre- and postcleaning), povidone-iodine bottle, quaternary ammonium and alcohol-based disinfectant solution containers, and cotton ball jar (ATP swab: n = 10 per environmental source; bacterial culture swab: n = 6 per environmental source). Chamber rims yielded the highest ATP relative light unit values compared with the other environmental sample groups and heavy growth on bacterial culture. A total of 16/36 (44%) swab samples from environmental sources yielded growth on bacterial culture, and clinically relevant bacterial species were identified in samples from the chamber rims, cotton ball jar, povidone-iodine bottle, and forceps. Although high ATP RLU levels and positive bacterial growth were identified for these environmental samples, there was a poor correlation between the ATP RLU values with the semiquantitative bacterial culture scores. Based on the results of this study, a high ATP RLU cutoff threshold would be needed to maximize the accuracy of using this method instead of bacterial culture to identify potential sources of microbial contamination. This study represents the first published microbial surveillance investigation of environmental samples from materials and solutions used in cranial implant chamber maintenance.