Figure 9.

Effect of prophylactic administration of StaphLyse™ (A) or amoxicillin (B) in the S. aureus mouse mastitis model. S. aureus ATCC 29740 was inoculated IMAM, at a concentration of 100 CFU in a volume of 100 µL, in the 2 fourth glands in lactating CD-1 mice separated from pups 1 h prior to infection. StaphLyse™ (10⁸ PFU per gland) or amoxicillin (AMX, 75 µg per gland) was administered via the IMAM route at either 4 h before infection (−4 h) or 4 h after infection (+4 h). Mammary glands were harvested 18 h after infection for determination of the bacterial load (CFU per gram of gland). Each dot on the graph represents the bacterial load for each gland, whereas whiskers show the minimum and maximum values. The horizontal bars within the boxes indicate the median value for each group. Log CFU differences between controls and tests are shown in italic. Statistical significance was evaluated by the Kruskal–Wallis comparison test followed by Dunn’s multiple-comparison tests (ns: not significant, ** p ˂ 0.01, *** p ˂ 0.001).