1. Department of Pediatrics, The University of Texas Medical Branch, Galveston, Texas, USA
2. Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, USA
3. School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
4. Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, USA