In Memoriam
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The recently deceased must have been an ASM Maryland Branch member at some point
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The Branch Board of Directors reserves the right to edit submissions for content and length
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A given obituary will remain posted on the website for at least 6 months
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Information may be requested such as a year of active membership or of Branch service, to be assessed at the discretion of the Branch Board of Directors
Dr. Kimberly E. Walker
Dr. Kimberly E. Walker, whose career in microbiology began and was so interwoven with institutions across Maryland and several adjoining states, as well as with the American Society for Microbiology, passed away on August 31, 2025. A viewing followed by a funeral service was held at St. Paul Baptist Church in Bethlehem, PA, on Tuesday, September 9, 2025. The following is her official obituary, courtesy of the Jesse Johnson Funeral Home.
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Dr. Kimberly E. Walker, Born on January 24, 1965, to Polly E Floyd Walker and the late Wilson Walker, in Bethlehem, Pennsylvania. passed away on August 31, 2025, in Wilmington, Delaware. A brilliant scientist, devoted educator, and beloved family member and friend, Kim’s life was marked by her profound faith in God and an unwavering commitment to knowledge, compassion, and community.
Kim graduated from Liberty High School in 1982 where she excelled as a part of the Honor society, Scholastic scrimmage debate team, Orchestra and Ensemble. She earned her Bachelor of Science in Medical Technology from the University of Maryland in 1986 and became certified as a Medical Technologist by the American Society for Clinical Pathology that same year—a credential she maintained throughout her life. Her academic journey continued with a Ph.D. in Microbiology and Immunology from the Medical College of Virginia at Virginia Commonwealth University in 1993.
Kim’s postdoctoral work reflected her deep dedication to scientific advancement. She held fellowships at the Center for Vaccine Development at the University of Maryland at Baltimore (UMAB), the Center of Marine Biotechnology at the University of Maryland Biotechnology Institute (UMBI), and a joint fellowship with the UMB Dental School and Morgan State University. Her passion for science extended beyond the lab when she served as a Congressional Science Fellow to Senator Paul Wellstone from 2000 to 2001—an experience that highlighted her belief in using science to inform public policy.
Her professional career began at Allentown Osteopathic Hospital in 1986–1987. After earning her doctorate, she joined the University of Maryland as an Assistant Professor of Medicine in the Department of Medical and Research Technology from 2001 to 2011. During this time, she also served as Graduate Program Director from 2006 to 2011. From 2011 to 2020, Kim worked as a Federal Specialist in Clinical Microbiology and Biosafety for the American Society for Microbiology in Washington D.C., where she helped shape national standards and practices.

In her later years, Kim continued her mission of education and mentorship as Program Director for CLSC and PHBT at Lorain County Community College (2020–2022) before joining the University of Delaware as Assistant Professor and Program Director for Medical Diagnostics in 2022—a role she held until her passing.
Dr. Walker was more than a scientist; she was a gifted communicator who could make complex scientific concepts accessible to all. Her students were not just pupils but extensions of her heart—she nurtured them with wisdom, humor, and fierce dedication.
Kim’s vibrant personality shone through her passions outside academia. She had an enduring love for music—especially traditional gospel, R&B artists such as Prince and Latin artists like Celia Cruz and Buena Vista Social Club—she also delighted in movies, often impressing friends with her encyclopedic knowledge of actors. Known for her signature style, she was rarely seen without a Coach purse slung over her shoulder or red lipstick tucked inside—her nails always painted “I’m Not Really a Waitress” red.
She cherished traveling to Puerto Rico to visit friends and basked in the island’s culture—particularly enchanted by the sound of the coquí frog that became one of her favorite memories.
Kim is deeply mourned by her mother Polly E. Walker; uncles Chappell Floyd, Marcellus Floyd, and Earl L. Floyd (Molly); aunts Rosetta Floyd Carey Barringer (Larry); numerous cousins; as well as her godsister, godson, goddaughter—friends, coworkers, and countless students whose lives she touched profoundly.
She now joins those who preceded her: her father Wilson Walker; grandparents Randall and Beulah Mae Walker along with Earlee Floyd, Beulah Mae Floyd Belle, and Louis P Belle; uncles Billy Floyd and Montfort Walker; aunts Barbara Watson, Rosita Floyd, and Nettie Ward; and Cousin Stacey Floyd.
Dr. Walker leaves behind a legacy rooted in intellect, empathy, advocacy, and joy—a legacy that will continue to inspire all who had the privilege to know her. May her memory bring comfort to those who loved her dearly.
Paulette Dew Hammond
It is with great sadness that we mark the passing of Paulette Hammond on August 29, 2025, a Baltimore area native who remained local as she pursued an education and then a lengthy career in microbiology. She was an integral member of and contributor to the ASM Maryland Branch, having been on the Board of Directors for some 30 years. Paulette’s most recent Branch positions were Secretary and then, in appreciation for her service, with the honorary title of Secretary Emeritus created specifically for her. A service was held for her at Christ the King Episcopal Church on Friday, September 26, 2025. Below is an obituary originally published by the Baltimore Sun on September 14, 2025.
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Paulette Dew Hammond (née Geisenkotter) passed away peacefully on August 29, 2025. She was born in 1946 to William P. Geisenkotter and Dorothy Dew Geisenkotter, and spent her formative years in Catonsville, Maryland. A dedicated student, she graduated from Catonsville High School and continued her education at the University of Maryland, College Park, where she earned a Bachelor of Science with honors in microbiology. She later received a Master of Science degree from the University of Maryland School of Dentistry in Baltimore.
Paulette's career began as a virologist at Maryland Department of Health in Baltimore, followed by her work at the University of Maryland Laboratory. She concluded her professional journey as Chief Virologist at Quest Diagnostics in Halethorpe. Her commitment to the scientific community was evident through her emeritus membership and service as secretary for many years with the Maryland Branch of the American Society for Microbiology.
A passionate advocate for the environment, peace, justice, diversity, equality, and inclusion, Paulette served on the boards of several non-governmental organizations, including the National Organization for Women (Buffalo Chapter), Maryland United for Peace and Justice, and the Maryland Conservation Council. She represented Maryland United for Peace and Justice and the Maryland Conservation Council in efforts such as the Citizens Campaign for the Environment and the Safe on Pesticides Coalition. Paulette was appointed to the State Commission on Environmental Justice and Sustainable Communities, and most recently, was a member of the board of trustees for CCBC.

Her faith was a guiding force throughout her life. As a member of Christ the King Episcopal Church in Woodlawn, Paulette served as facility coordinator and treasurer of the vestry, participated on the Diocesan Council, and acted as delegate to its annual convention. She also devoted her time to the church's ministry focusing on Refugee and Immigrant Services and Empowerment.
Paulette valued living life fully. Away from her advocacy and professional work, she enjoyed cuddling her rescued cats, tending to her cherished house plants, reading, and traveling. Friends held a special place in her heart, and she prioritized visiting them even when distance made it challenging. She was an active member of The Salon Group and the "Gourmet Club." Paulette's kindness, warmth, exuberant laugh, spirited reactions during Ravens games, and her unique footwear and hosiery choices are memorable parts of her legacy. She will be missed,
She is survived by her daughter, Carolyn Hammond Ferrell and husband Ray; her sister, Deborah Dew Geisenkotter and husband Richard Worsham; and her foster daughter, Niesha, along with Niesha's children, plus cousins and numerous friends.
Paulette requested that donations in her memory should be made to Planned Parenthood of Maryland or the Maryland League of Conservation Voters.


Dr. Joseph P. Libonati
A long-time member of the Maryland Branch of the ASM, passed away on October 20, 2020. Joe served as the Maryland Branch President in 1973 and continued as a regular attendee at Branch meetings until just prior to the Covid-19 shutdown. Joe was well-known as being one of the friendliest and most dedicated Branch members.
Dr. Libonati received his PhD at the University of Maryland Baltimore and continued to collaborate with investigators there long after he received his degree. Most notably, he co-authored a number of highly cited papers on human challenge studies for cholera, dysentery, typhoid fever and other enteric diseases. ( https://pubmed.ncbi.nlm.nih.gov/?term=libonati+jp ) In 1966, he joined the Maryland Department of Health where he had a long and distinguished career, retiring in 1997 as Deputy Director of Laboratories Administration. In retirement, he continued to consult on microbiology, attend Maryland ASM Branch meetings and lectured at the Johns Hopkins University. Besides his work on enteric diseases with University of Maryland investigators, he published a number of other papers on Mycobacterium tuberculosis, Neisseria gonorrhea, and other pathogens.
In describing Joe as a person, we cannot improve upon the obituary published at the Ruck Funeral Home site ( https://www.ruckfuneral.com/obituary/dr-joseph-libonati ), which is given below.
Dr. Joseph P. Libonati, microbiologist, former Deputy Director of Laboratories Administration for the Maryland Department of Health and Mental Hygiene, Lecturer at Johns Hopkins University, and fan of science fiction, peacefully departed Earth on October 20, 2020 to boldly go where no man has gone before.
“Joe” was born in 1941 in Philadelphia, Pennsylvania as the first son of Paschal and Paula Libonati and one of eight children. Surrounded by his older sisters, Marie, Peggy, and Paula; his twin sister Joanne; and his younger siblings Betty, John, and Frank, Joe’s adventurous spirit led him to discover the streets and underground passageways of Philadelphia, and later the back roads, chicken coops, and blackberry and sumac brambles of Blackwood Terrace, New Jersey. Returning to Carlton Street, Philadelphia, Joe graduated from Roman Catholic and did his undergraduate studies at St. Joseph’s University. He navigated the tunnels of Pittsburgh to attend Duquesne University for his master’s. His pursuit of knowledge led him to the University of Maryland in Baltimore for his PhD in microbiology. While there, he noticed a young nursing student, Carol Kubeluis, whom he eventually approached to ask out - apparently first telling her he worked for the telephone company. Despite that original ploy for a date, Carol and Joe married and celebrated their 51st wedding anniversary in February. Three daughters, Genevieve, Rachel, and Stephanie, filled their Baltimore home leaving Joe outnumbered. The family dogs over the years, Frodo, Elmo, and Rocky, were not only important members of the family but also provided male companionship to Joe, a role his “lunch buddy” Elmo undoubtedly fulfilled. Joe ensured that his daughters were well-prepared for their own adventures in life, teaching them to paint houses, change tires, install burglar alarms, and perform basic home repair as well as offering financial advice and always being available when help was needed. He served for many years on the Board of Trustees for Mercy High School to assist other young women in their pursuit of education.
As Dr. Libonati, Joe conducted research on tuberculosis, shigellosis, cholera, and salmonella devoting his professional life to public health. After 31 years at the Maryland State Laboratories, he retired in 1997 but continued his dedication to the field consulting and teaching microbiology and biotechnology at Johns Hopkins. He was for many decades an active member of the American Society of Microbiology.
Joe enjoyed the pursuit of good, reasonably priced wine: his friends and family enjoyed the fruits of that labor. He was also known to fix anything that needed fixing (except Carol’s binoculars), setting up computers for friends and family, mowing the neighbor’s lawn, grilling a well-done steak, and enjoying a cold beer (or some bourbon). September in Maine has been his favorite vacation spot for the last decade or so, with plenty of homemade pie and “lobstah.” Prior to that, Joe enjoyed traveling, not only to the beaches in Bethany, Delaware but also to Europe and South America. Whether it was introducing Italy to a daughter or being shown Germany by another daughter, Joe loved to discover new places. Joe also had a great love for chocolate and afternoon walks with his best buddy. Joe will be remembered by his hilarious jokes, sharp wit, and caring kindness that would surface when you weren’t expecting it.
Joe reached his final frontier in his battle with what was originally thought to be Parkinsons and later diagnosed as PSP. His companions at Maryland Association for Parkinson Support, and in particular at their exercise programs, helped him and Carol navigate this illness with friendship and empathy. His humor, friendship, and honor in life will not be forgotten by his family, friends, and colleagues. Joe is survived by his wife Carol; daughters Genevieve, Rachel, and Stephanie; sons-in-law Franklin Bermeo and Harald Landmann; grandson Rasmus, and eight grand puppies.
For those who wish to remember Joe with a donation to an organization that mattered to him, his family suggests the Maryland Association for Parkinson Support (www.marylandparkinsonsupport.org ) or Mercy High School (www.mercyhighschool.com ). Or maybe just tune-up your car and check the air pressure in your tires - he would have wanted that.


Mark E. Shirtliff, PhD
Mark E. Shirtliff, PhD, served as President of the Maryland Branch of the American Society for Microbiology from 2007-2008. He was a Professor in the Department of Microbial Pathogenesis in the University of Maryland School of Dentistry with a secondary appointment as Professor in the Department of Microbiology and Immunology in the School of Medicine. Dr. Shirtliff began his training at the University of Texas Medical Branch in the Department of Microbiology and Immunology, where he received his PhD in 2001 with his thesis titled “Staphylococcus Aureus: Roles in Osteomyelitis.” He then moved to the international training center for biofilm research, the Center for Biofilm Engineering in Bozeman, Montana, as a Post Doctoral Fellow to continue his work on biofilms and biofilm-related diseases with the late Dr. Bill Costerton and Dr. Anne Camper as mentors. Dr. Shirtliff became an Assistant Research Professor in 2003 in the Department of Microbiology at Montana State University and later that year accepted a position as Assistant Professor – tenure track in the School of Dentistry at the University of Maryland, Baltimore and was promoted to Full Professor with tenure in 2017. Until his very untimely death in July 2018, Dr. Shirtliff continued his research and teaching interests in biofilms and had many successful graduate students and post doctoral fellows who moved on to successful careers at various academic & government institutions.
John M. DeBoy, 2nd
Retired Public Health Laboratory Scientist and Director
Our friend and colleague, Dr. John (Jack) M. DeBoy, 2nd, a public health laboratory scientist and former director of the Maryland Laboratories Administration, died of renal cancer on October 8, 2019. He was 73.
A Baltimore native, he earned degrees in zoology (1969) and microbiology (1977) from the University of MD. He also earned MPH (1978) and DrPH (1980) degrees in Public Health Laboratory Practice from the Univ. of NC in Chapel Hill and the Centers for Disease Control (CDC) in Atlanta. In his early career, he worked in the MD Laboratories Administration in Baltimore, then, while in the Army, at the 4th/5th U.S. Army Medical Laboratory at Ft. Sam Houston in San Antonio, TX. After military service he was employed in the Maxcy Laboratories at the Johns Hopkins School of Hygiene and Public Health, and in the Microbiology Dept. of the Hopkins Medical School. After graduate school he served as director of laboratory operations for the Diagnostic Laboratory in the NY State College of Veterinary Medicine at Cornell University in Ithaca, NY. He then accepted a postdoctoral fellowship in Medical and Public Health Microbiology at Washington University Medical center in St. Louis, MO.
He returned to the Department of Health and Mental Hygiene’s (DHMH’s) Laboratories Administration in 1984, and became its Director from 2003-2011. In addition to directing Maryland’s state public health laboratory systems, he also oversaw DHMH’s Division of Drug Control serving on numerous departmental, State-wide, federal, and professional committees, and task forces over four decades in public health. He served on various boards of directors including the American Academy of Microbiology, the National Registry of Microbiologists, the Maryland Public Health Association, the Association of Public Health Laboratories (APHL), and the Alpha (Johns Hopkins) Chapter of Delta Omega, the National Public Health Honorary Society.
Dr. DeBoy was instrumental in drafting and shepherding many State bills and regulations dealing with medical laboratories, tissue banks, forensic laboratories, and employment-related drug testing. He also testified before the Maryland General Assembly and Congress on behalf of DHMH and APHL. Between 2003 and 2011 he played a key role in obtaining initial planning funds and then overseeing the multi-year design process for the Laboratories Administration’s current central laboratory in East Baltimore. After retiring from DHMH he worked for several years as a volunteer or part-time, independent consultant for APHL, the Centers for Disease Control, the Baltimore City Health Dept., several private companies, and as a Research Analyst for the federal EPA at Ft. Meade, MD. Jack also volunteered many years working on the doctoral program for laboratories at a Florida University.
During his 50 year career in public health, Dr. DeBoy was a MD Government Executive Institute recipient, a winner of the Maryland Public Health Association’s President’s Award, a recipient of the Public Health Leadership Institute’s Martha Katz Award for Public Health Leadership, and winner of APHL’s Gold Standard Award for Public Health Laboratory Excellence.
In honor of Jack’s memory, the John M. DeBoy II Scholarship Fund will be established. Donations will be accepted at a future date for this fund. The Maryland Branch, ASM, offers its condolences to Jack's wife, Lorraine Kelly, and his family and to his public health colleagues in Maryland.
