Fig. 1: PRISMA flow diagram of search strategy.

A systematic search strategy encompassed PubMed and the FDA 510(k) Premarket Notification and FDA Premarket Approval (PMA) databases. Iterative internet searches and consultation with content experts in microbiology and bio/biomedical engineering were used to probe for lacunes in our search strategy. Technologies were included if they relied on phenotypic antimicrobial susceptibility profiling of bacteria, regardless of the recognition element used. Rapid technologies were defined as those offering a faster time-to-final-result than those possible with conventional clinical microbiology methods. Phenotypic tests were defined as those that measure microbial growth or viability in the presence of antimicrobials to determine susceptibility. Hypothesis-free nucleic acid-based tests were defined as those using genomic recognition elements to detect or quantify bacteria in the presence of different antimicrobial conditions without pre-defined targets. We considered methods using nucleic acid-based recognition elements in a distinct category of technologies to facilitate comparison between them. We only included technologies with publications that specifically addressed their application to phenotypic AST. Finally, we only considered technologies used for non-mycobacterial vegetative bacteria routinely isolated in clinical laboratories. We considered as “commercialized” any AST technology with any of the following: FDA authorization, approval, or a pre-market notification; European Economic Area CE marking; or authorization by another WHO-Listed Authority (WLA) if specified by authors. All others were considered “non-commercialized”.