The Division of Infectious Diseases and Global Public Health and the Department of Medicine are saddened to announce the death of Donald Guiney, M.D. Professor of Medicine in the Division of Infectious Diseases at The University of California, San Diego School of Medicine. He died peacefully at Jacobs Medical Center surrounded by his loving family.  He was 71 years old.

Don’s family moved to Southern California from Colorado when he was five years old because of Don’s asthma. He told his children that these early experiences with physicians inspired him to become a physician. After majoring in chemistry at Pomona College, Don was one of the elite students admitted to the first two classes of the new UCSD School of Medicine. After residency in Internal Medicine at LA County/USC, he returned to UCSD as an Infectious Diseases fellow with A.I. Braude, Chief of Infectious Diseases in the Department of Medicine.  His medical school thesis research was on the method of replication of R plasmids, and that interest led him to devote his entire research career to defining the role of plasmids in infectious diseases.  Early in his academic career he discovered plasmid-mediated resistance to trimethoprim/sulfa, and did pioneering research on DNA transfer between different bacterial species with vastly different oxygen requirements and metabolic pathways, and on the mechanisms of antibiotic resistance in Bacteroides fragilis.

From mid-career on, Don turned to analysis of Salmonella virulence plasmids and was instrumental in answering the perplexing question of why some Salmonella serovars like Dublin and Choleraesuis were more likely to cause bacteremia than diarrhea. He showed that their invasiveness was due to a highly conserved operon encoding five genes in all the virulence plasmids of invasive serovars, including the strains of Typhimurium that are responsible for Salmonella bacteremia throughout sub-Saharan Africa. More recently, he and collaborators showed that Salmonella serovars that cause predominantly diarrhea alter ion transporters causing a net loss of fluid from the intestine.  Don also made contributions to our understanding of H. pylori pathogenesis and immunity to listeriosis and anthrax. His achievements were recognized by election to membership in the Western Association of Physicians, and the American Society for Clinical Investigation. Only weeks before he died, he delivered the Braude Memorial lecture at Medical Grand Rounds on his Salmonella research.

Don was the proverbial triple threat of academic medicine. He was a superb clinician and teacher at the bedside and in the classroom, where his lectures on bacterial genetics and the mechanisms of antibiotic resistance were considered classics by students and faculty. Infectious Diseases fellows admired him for his insightful diagnostic skills and for bringing science to the bedside to explain the pathogenesis of disease.

Don was immersed in family activities, including tennis, hiking, horsemanship, and a shared appreciation of classical music. He is survived by Susan Guiney, his wife of 49 years, his daughters Laura Guiney and Justine Gervase, his son Daniel Guiney, his granddaughter Juliet Gervase, his son-in-law Matt Gervase, and Matt’s son, Paiton.

Don’s life will be celebrated from 5-7 P.M. at the UCSD Faculty club on July 18th if COVID-19 regulations permit. In lieu of sending flowers, the family requests that donations be made in Don’s memory to a UCSD School of Medicine Award for graduating medical students in his name. To donate online, go to https://giveto.ucsd.edu/ and search for Fund F-6891.  Donations may also be submitted by checks made payable to the UC San Diego Foundation, noting that the gift is in memory of Dr. Donald Guiney tothe fund: F-6891.  Mail checks to UC San Diego Gift Processing, 9500 Gilman Drive, #0940, La Jolla, CA 92093-0940.

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