Chlamydial pre-infection protects from challenge with a 100% lethal dose of HSV-2.

<p>(A) Female BALB/c mice were singly-infected with either 10⁵ PFU HSV-2 (H5) or with 10⁶ IFU <i>C</i>. <i>muridarum</i> (Cm). Super-infected mice were infected with Cm on day 0 pci and the high inoculum of HSV-2 on day 3 pci (Cm-3D-H5). Morbidity and mortality resulting from HSV-2 was monitored daily and the percent survival between experimental groups was compared using the log rank statistic. Significant (p<0.05) difference between HSV-2 singly-infected controls and super-infected group is indicated by an asterisk (*). The survival curve depicts data combined from 2 separate experiments with n = 16 for Cm and n = 20 for both the H5 and Cm-3D-H5 groups. (B) Chlamydial shedding was determined by chlamydial titer assay and is reported as average IFU/mouse +/- SEM. (C) Average chlamydial shedding at day 3 pci (indicated by bars) and individual mouse chlamydial shedding (segregated according to survival status) are shown; n = 8 for Cm (circles) and n = 12 for Cm-3D-H (triangles). (D) HSV-2 recovery was determined by plaque assay and is reported as average PFU/mouse +/- SEM. (E) Average HSV-2 recovery at day 6 pci (indicated by bars) and individual mouse HSV-2 recovery (segregated according to survival status) are shown; n = 12 for both HSV-2 (circles) and Cm-3D-H (triangles). (C and E) Survivor and non-survivor mice are indicated by S and NS, respectively. The data in panels C-F are representative of 2 independent experiments. Differences in pathogen shedding/recovery between groups were determined with the paired Student’s t-test with p<0.05 considered significant, as indicated by an asterisk (*).