Simkania negevensis, an Example of the Diversity of the Antimicrobial Susceptibility Pattern among Chlamydiales

In past years, several Chlamydia-related bacteria have been discovered, including Simkania negevensis, the founding member of the Simkaniaceae family. We evaluated the antimicrobial susceptibility patterns of this emerging intracellular bacterium and highlighted significant differences, compared with related Chlamydiales members. S. negevensis was susceptible to macrolides, clindamycin, cyclines, rifampin, and quinolones. Importantly, unlike other Chlamydiales members, treatment with β-lactams and vancomycin did not induce the formation of aberrant bodies, leading to a completely resistant phenotype.