Conversations with the Director: Brandi Limbago, PhD

January 9, 2015

People who don’t work at CDC (and some who do) might need a medical dictionary to follow the conversation between CDC Director Tom Frieden, MD, MPH, and Brandi Limbago, PhD. Limbago is deputy director of the Division of Healthcare and Quality Promotion’s (DHQP’s) Clinical and Environmental Microbiology Branch, and Frieden began his medical career as an infectious disease physician. The similarity between their backgrounds makes them both fluent in what could seem like a foreign language. As the two met for this Conversation with the Director, Frieden was interested to learn about Limbago’s academic background, as well as her professional accomplishments and current responsibilities.

“Where are you from originally?” began Frieden after being introduced. “Idaho,” replied Limbago. “So how did you end up here? And with a bachelor’s degree in zoology and philosophy; not two things you see tied together often,” Frieden continued. Limbago explained that “I’ve always been interested in philosophy, but figured I may actually need a job some day.” She attended graduate school at Emory to study microbiology and molecular genetics but planned to leave the South because “it was too hot, and there were too many trees—you couldn’t see anything.” After graduating from Emory, she returned west to Seattle, where she worked for Children’s Hospital and Regional Medical Center and the University of Washington. She found her way back to Atlanta after accepting a position with CDC as lead of DHQP’s former Diagnostic Microbiology Team. Since then, she’s held two other positions with DHQP. She went on to say that, “I love the people I work with. I work with such smart, passionate people. That part makes it all worth it.”

So, tell me about a project that you’ve worked on that was particularly interesting or exciting,” inquired Frieden. Limbago replied eagerly, “We spend a lot of time focusing on Carbapenem-resistant Enterobacteriaceae (CRE)—performing reference testing and looking at emerging mechanisms. The Enterobacteriaceae aren’t like MRSA (methicillin-resistant Staphylococcus aureus), which is one organism. It’s an entire family—so it’s huge. We also deal with multiple resistance mechanisms, like Klebsiella pneumoniae carbapenemase, or KPC, that are known to spread clonally but can also be acquired independently. There’s rarely a boring moment. I also serve on the Clinical and Laboratory Standards Institute (CLSI) Subcommittee on Antimicrobial Susceptibility Testing. CLSI manages laboratory standards for all aspects of the clinical world.”

He continued, “Your group has worked on MRSA a fair amount. Tell me about that.” She replied, “Well, there are two different strains—healthcare MRSA and community MRSA. There are different strain backgrounds, and the virulence potential differs for both. Healthcare strains are primarily in people who have healthcare exposures and underlying conditions—like surgery or suppressed immune systems. The community strain emerged separately from health care and can cause very serious infections in healthy people. At least now people are recognizing that MRSA happens in community settings. That’s an important development.”

As the conversation proceeded, Frieden spoke about some of his early experiences in his medical career working on drug resistant bacteria and asked how things had progressed. “So penicillin used to be effective against Strep. What’s happening with the minimum inhibitory concentrations?” Limbago replied, “It’s still pretty effective against Strep, and for Staph, penicillin is an amazing drug for susceptible strains.” Frieden resumed with how he remembered his father telling him about his medical school years and how, during that time, “Endocarditis was treated with a much smaller amount of penicillin than we use now, and patients would often improve with only one or two doses.” He then admitted, “There’s a lot we don’t understand.”

Frieden was also very interested in the makeup of DHQP’s Clinical and Environmental Microbiology Branch and how it functioned. “Our group contains a healthcare environment side and a clinical microbiology side; our whole group contains about 40 people,” Limbago said.

The clinical microbiology side of the group conducts testing in compliance with the Clinical Laboratory Improvement Amendments (CLIA) requirements, including reference tests to identify pathogens and to test pathogen for antimicrobial susceptibility. “We also provide lab support for large surveillance programs for MRSA, CRE, and Clostridium difficile, and we have smaller studies as well,” Limbago said. “Most of our targeted surveillance is for the most resistant organisms, but we don’t want to lose sight of the garden varieties out there too.”

The healthcare environment side of Limbago’s group works on healthcare-associated outbreaks and the role of the healthcare environment. “We’re focused on the setting (health care), where outbreaks can be caused by a wide variety of organisms,” she explained. “Our group also has the capacity to culture environmental specimens implicated in these outbreaks, and this expertise is rare. Both sides of our branch work together to study both emerging and common causes of healthcare-associated infections, and that’s honestly the beauty of the group.”

As the conversation drew to a close, Frieden gave Limbago a chance to switch roles and question him. She asked with a smile, “So, how do you like it here?” which made the director beam. He answered, “I love it. I’m excited anytime I get to meet people who are enthusiastic about their work and can teach me something. I like learning new things.”

Frieden commented, “Since I’ve been the director, the one thing that’s been impressive to me is realizing just how important our labs are. We are the de facto reference lab for the world. Our ability to speak definitively rests on the bedrock of the fantastic lab work that’s being performed all over the agency.”

Limbago remarked, “I appreciate that you are very results-oriented and that you are looking to see the impact of the work we do.”

As the chat ended and they both gathered their belongings to leave the room, Frieden said, “You never know what the next outbreak will be caused by…” Limbago emphatically agreed.