Journal Article

Chlamydial Pre-Infection Protects from Subsequent Herpes Simplex Virus-2 Challenge in a Murine Vaginal Super-Infection Model

Slade, Jessica, Hall, Jennifer V., Schoborg, Robert V., Kintner, Jennifer

2016

Overview

Chlamydia trachomatis and Herpes Simplex Virus-2 (HSV-2) genital tract co-infections have been reported in humans and studied in vitro but the clinical consequences are unknown. Limited epidemiologic evidence suggests that these co-infections could be more severe than single infections of either pathogen, but the host-pathogen interactions during co-infection remain uncharacterized. To determine whether disease progression and/or pathogen shedding differs between singly-infected and super-infected animals, we developed an in vivo super-infection model in which female BALB/c mice were vaginally infected with Chlamydia muridarum (Cm) followed later by HSV-2. Pre-infection with Chlamydia 3 or 9 days prior to HSV-2 super-infection conferred significant protection from HSV-2-induced neurologic disease and significantly reduced viral recovery compared to HSV-2 singly-infected controls. Neither protection from mortality nor reduced viral recovery were observed when mice were i) super-infected with HSV-2 on day 27 post Cm; ii) infected with UV-irradiated Cm and super-infected with HSV-2; or iii) azithromycin-treated prior to HSV-2 super-infection. Therefore, protection from HSV-2-induced disease requires active infection with viable chlamydiae and is not observed after chlamydial shedding ceases, either naturally or due to antibiotic treatment. Thus, Chlamydia-induced protection is transient and requires the continued presence of chlamydiae or their components. These data demonstrate that chlamydial pre-infection can alter progression of subsequent HSV-2 infection, with implications for HSV-2 transmission from co-infected humans.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Animals / Antibiotics / Azithromycin / Azithromycin - therapeutic use / Bacteria / Chlamydia / Chlamydia Infections - complications / Chlamydia Infections - drug therapy / Chlamydia Infections - microbiology / Chlamydia Infections - virology / Chlamydia trachomatis / Chlamydia trachomatis - isolation & purification / Chlamydia trachomatis - physiology / Chlamydia trachomatis - radiation effects / Coinfection / Disease control / Disease Progression / Epidemiology / Female / Genital tract / Health aspects / Herpes Genitalis - complications / Herpes Genitalis - microbiology / Herpes Genitalis - prevention & control / Herpes Genitalis - virology / Herpes simplex / Herpes viruses / Herpesvirus 2, Human - isolation & purification / Herpesvirus 2, Human - physiology / Herpesvirus infections / HIV / Host-Pathogen Interactions / Human immunodeficiency virus / Infections / Infectious diseases / Infertility / Inflammation / Influenza / Medical research / Medicine / Mice / Mice, Inbred BALB C / Paraplegia - etiology / Paraplegia - virology / Pathogens / Prevention / Preventive medicine / Recovery / Sexually transmitted diseases / Shedding / STD / Studies / Superinfection / Time Factors / Vagina / Vaginosis, Bacterial - complications / Vaginosis, Bacterial - drug therapy / Vaginosis, Bacterial - microbiology / Vaginosis, Bacterial - virology / Viral Load / Viruses / Womens health