Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA
Daniel V. Zurawski
Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
Elena K. Gaidamakova
Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
Vera Y. Matrosova
Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
John K. Tobin
Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA
Taralyn J. Wiggins
Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA
Ruth V. Bushnell
Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA
David A. MacLeod
Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA
Yonas A. Alamneh
Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
Rania Abu-Taleb
Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
Mariel G. Escatte
Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
Heather N. Meeks
Defense Threat Reduction Agency, Ft. Belvoir, VA 22060, USA
Michael J. Daly
Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
Gregory J. Tobin
Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA
Acinetobacter baumannii is a bacterial pathogen that is often multidrug-resistant (MDR) and causes a range of life-threatening illnesses, including pneumonia, septicemia, and wound infections. Some antibiotic treatments can reduce mortality if dosed early enough before an infection progresses, but there are few other treatment options when it comes to MDR-infection. Although several prophylactic strategies have been assessed, no vaccine candidates have advanced to clinical trials or have been approved. Herein, we rapidly produced protective whole-cell immunogens from planktonic and biofilm-like cultures of A. baumannii, strain AB5075 grown using a variety of methods. After selecting a panel of five cultures based on distinct protein profiles, replicative activity was extinguished by exposure to 10 kGy gamma radiation in the presence of a Deinococcus antioxidant complex composed of manganous (Mn2+) ions, a decapeptide, and orthophosphate. Mn2+ antioxidants prevent hydroxylation and carbonylation of irradiated proteins, but do not protect nucleic acids, yielding replication-deficient immunogenic A. baumannii vaccine candidates. Mice were immunized and boosted twice with 1.0 × 107 irradiated bacterial cells and then challenged intranasally with AB5075 using two mouse models. Planktonic cultures grown for 16 h in rich media and biofilm cultures grown in static cultures underneath minimal (M9) media stimulated immunity that led to 80–100% protection.
