Challenges in identifying antibiotic resistance targets for point-of-care diagnostics in general practice

Mitsakakis, Konstantinos; Kaman, Wendy E; Elshout, Gijs; Specht, Mara; Hays, John P

The detection of an antibiotic resistance gene within a clinical sample does not automatically mean that the causative bacterial pathogen of an illness actually carries the resistance gene detected. This is especially true for transferable genes present on MGE, where identical antibiotic resistance genes can be widely spread, not only within bacterial pathogens, but also within the normal human microbiota of the patient [31] . If an antibiotic resistance gene is found to be present in the clinical sample, how can the clinician be sure that the antibiotic resistance gene is present within the bacterial pathogen actually causing the disease and not present in a 'harmless' member of the patient's microbiota? [32] [33] [34] . Focusing on the detection of MGE-associated antibiotic resistance genes may partially get around the problem associated with the presence of antibiotic resistance genes within the human microbiota, as these are likely to be able to be transferred to pathogenic bacteria. Additionally, the GP may have to take note of any recent exposure of the patient to antibiotics, as antibiotic resistance generated by previous exposure to antibiotics could persist within the patient's human microbiota for some time [35] [36] [37] [38] [39] . Note also that as more antibiotic resistance targets are included in a POC diagnostic, the chance of detecting antibiotic resistance genes in the normal human microbiota (including nonpathogenic microorganisms) of the patient will also increase, possibly yielding 'false positive' results -at least with respect to the antibiotic sensitivity of the actual pathogen [40] .