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On the evolutionary ecology of multidrug resistance in bacteria

Fig 2

Example of a set of resistance profiles from a system with five strata and four antibiotics.

Each row in the table corresponds to the resistance profile of one isolate—i.e. there are three isolates from each strata (equal sampling/size of strata is not necessary). Competitive exclusion within a stratum means all isolates from one stratum have the same resistance profile. The strata have been arranged from top to bottom in order of decreasing resistance proneness (). The antibiotics have been arranged left to right in order of increasing resistance threshold (), or, equivalently, decreasing resistance frequency. Resistance to a particular antibiotic outcompetes sensitivity in a stratum when the resistance proneness of the stratum is greater than the resistance threshold of the antibiotic. Resistance proneness being independent of antibiotic and resistance threshold being independent of stratum leads to nested resistance profiles (i.e. rarer resistances only observed in the presence of more common ones) and complete linkage disequilibrium between resistances. See Fig A in S1 Text for an example of a set of non-nested resistance profiles.

doi: https://doi.org/10.1371/journal.ppat.1007763.g002