title: Broad-spectrum antibiotic or G-CSF as potential countermeasures for impaired control of bacterial infection associated with an SPE exposure during spaceflight.
abstract: A major risk for astronauts during prolonged space flight is infection as a result of the combined effects of microgravity, situational and confinement stress, alterations in food intake, altered circadian rhythm, and radiation that can significantly impair the immune system and the body's defense systems. We previously reported a massive increase in morbidity with a decrease in the ability to control a bacterial challenge when mice were maintained under hindlimb suspension (HS) conditions and exposed to solar particle event (SPE)-like radiation. HS and SPE-like radiation treatment alone resulted in a borderline significant increase in morbidity. Therefore, development and testing of countermeasures that can be used during extended space missions in the setting of exposure to SPE radiation becomes a serious need. In the present study, we investigated the efficacy of enrofloxacin (an orally bioavailable antibiotic) and Granulocyte colony stimulating factor (G-CSF) (Neulasta) on enhancing resistance to Pseudomonas aeruginosa infection in mice subjected to HS and SPE-like radiation. The results revealed that treatment with enrofloxacin or G-CSF enhanced bacterial clearance and significantly decreased morbidity and mortality in challenged mice exposed to suspension and radiation. These results establish that antibiotics, such as enrofloxacin, and G-CSF could be effective countermeasures to decrease the risk of bacterial infections after exposure to SPE radiation during extended space flight, thereby reducing both the risk to the crew and the danger of mission failure.
authors: Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Minghong
authors: M
authors: Li
authors: Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Veronica
authors: V
authors: Holmes
authors: Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Houping
authors: H
authors: Ni
authors: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Jenine K
authors: JK
authors: Sanzari
authors: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Ana L
authors: AL
authors: Romero-Weaver
authors: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Liyong
authors: L
authors: Lin
authors: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Alejandro
authors: A
authors: Carabe-Fernandez
authors: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Eric S
authors: ES
authors: Diffenderfer
authors: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Ann R
authors: AR
authors: Kennedy
authors: Division of Infectious Diseases, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA 19104, United States of America.
authors: Drew
authors: D
authors: Weissman
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001424:Bacterial Infections / Q000517:prevention & control*; D000077422:Enrofloxacin; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D051379:Mice; D019445:Solar Activity; D013026:Space Flight
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D016179:Granulocyte Colony-Stimulating Factor; D000077422:Enrofloxacin