Two Distinct Coagulase-Dependent Barriers Protect Staphylococcus aureus from Neutrophils in a Three Dimensional in vitro Infection Model (original) (raw)
Figure 1
Growth phenotypes of S. aureus Newman strains in different environments.
Growth phenotypes of S. aureus Newman strains under different growth conditions were analyzed 16 h after inoculation without agitation. Growth in RPMI 1640 leads to cluster formation of variable size (A). Growth in 3D-CoG also leads to cluster formation (B). Addition of 3 mg/ml fibrinogen to the medium (3D-CoG/Fib) resulted in the formation of discrete microcolonies of uniform diameter, surrounded by an inner pseudocapsule (yellow arrowheads) and an outer dense microcolony-associated meshwork MAM (blue arrowheads) (C). The sae mutant (Newman-29) formed clusters comparable to wildtype, even in 3D-CoG/Fib (D). A coa mutant formed microcolonies which were irregularly shaped in comparison to the wildtype, MAM formation was unaffected (E). A vWbp emp double mutant was unaffected in formation of the inner pseudocapsule but was devoid of any outer MAM (F). A1-F1: 40x oil immersion objective, scale bar 25 µm. A2-F2: 10x objective, scale bar 200 µm.