Histopathological scores of lungs in SIV- and MRSA-infected pigs. The average microscopic lung lesion scores were graded on a scale of 0 to 4 based on the severity of inflammation as mild, moderate, severe, or very severe. Average microscopic lesion score is depicted for MRSA only (), SIV only (), and dual-infected () animals on multiple sections of the lung from each animal. Values represent mean with standard error.