IFNG and coinfection: A variety of stimuli induce Chlamydia persistence including several antibiotics, gamma-interferon (IFNγ), deprivation of essential nutrients (i.e., iron, amino acids, glucose), heat-shock, components found on cigarette smoke, exposure to adenosine, infection with chlamydiaphage, co-infection with Herpes Simplex Virus or Porcine Epidemic Diarrhea Virus (Beatty et al., 1994b; Hsia et al., 2000; Wiedeman et al., 2005; Huston et al., 2008; Pettengill et al., 2009; Vanover et al., 2010; Schoborg, 2011; Prusty et al., 2012; Schoborg and Borel, 2014).