Meeting Abstract
P2.38 Sunday, Jan. 5 15:30 Survival of the coral pathogen Serratia marcescens and the development of a model organism for studying coral disease SINGLETON, E.M.*; SUTHERLAND, K.P.; GOODMAN, K.M.; LIPP, E.K.; Rollins College; UGA emn7070@uncw.edu
Populations of elkhorn coral (Acropora palmata) in the Florida Keys are facing a precipitous decline due to white pox disease, or acroporid serratiosis (APS). Untreated wastewater has been identified as a definitive source of the human enteric bacterium Serratia marcescens, the causative agent of APS. To better understand the etiology of APS, this study characterized the persistence of S. marcescens strain PDR60 isolates and strain PDL100 in seawater microcosms amended with glucose. The isolates with the shortest and longest survival times in glucose microcosms were isolate 2 and isolate 3, respectively (both PDR60 from APS-affected A. palmata). Isolate 2 lived for 21 days while isolate 3 lived for 127 days and was still alive at the end of this study. We also observed extended survival time of 156 days for isolate 8 (from wastewater in the Florida Keys) in seawater alone. In addition to survivability studies, we conducted experiments to determine if Aiptasia pallida, a sea anemone, can be used as a model organism to study the effects of APS. We inoculated A. pallida polyps with 106 cfu/ml of the most virulent S. marcescens isolate, isolate 6 (from wastewater in the Florida Keys), which killed A. palmata corals in ~4 days (Sutherland et al. 2011). After 4 days, A. pallida did not display any visual signs of stress, indicating that isolate 6 was not lethally virulent under the conditions of this study. The survivorship curves of A. pallida (non-clonal and clonal lines) inoculated with S. marcescens were no different from controls (p = 0.124 and p = 1.0, respectively). These results indicate that S. marcescens can persist in the environment for longer than expected and represent a starting point for further research on using A. pallida as a model organism.
