Fig. 2.

Following Reynolds infection the early damage to surrounding tissue is controlled better. Mice (n=4–6 mice per group/time point) were injected with either agarose-laden S. aureus strain RN6390- or S. aureus strain Reynolds-beads (10⁴CFU) as described in the Materials and methods. Animals were euthanized at the indicated time points, whereupon brain tissues were flash frozen on dry ice for subsequent cryostat sectioning. Serial sections were prepared throughout the entire abscess to ensure that the maximal cross-sectional area was identified and stained with H & E to demarcate the histological appearance of lesions. (A) Stained slices were imaged under 1.25× objective to visualize the whole section. Lesions from 3 individual animals/group are presented to demonstrate the extent of abscess formation. (B) Abscess area (mm²; mean±SEM) was quantitated using the MetaMorph image analysis program by measuring the two largest lesion sizes for each tissue specimen. Significant differences in brain abscess size between S. aureus RN6390- and Reynolds-infected mice are denoted with asterisks (*, p<0.05). Results are mean of three independent experiments.