Hello, everyone. Welcome and thank you for joining. We'll get started in just a minute. We'll give other 
attendees just a second to join in. We'll get started in just a minute. Thank you again for joining our 
OneLab Network event today. 
All right, it looks like we've got a good amount of people in the room now. So let's go ahead and get 
started. Welcome, everyone. Thank you for joining. My name is Chelsea Parsons, and I'm a consultant 
with Guidehouse, supporting CDC'S OneLab Initiative. 
I just have a couple of things to bring up before we start the webinar. If you have any technical issues 
throughout the session today, or if you know of any of your colleagues having any issues, you can email 
our OneLab inbox. We'll have someone monitoring that and supporting you there. So it's 
onelab@cdc.gov. That's onelab@cdc.gov. You'll see that address just pop up in the chat. 
If you have questions regarding the session materials and content today, please put those in the Q&A 
function. So in your bottom ribbon of your Zoom desktop app right now, you'll see a Q&A button there. 
You can add questions in there throughout. We will have a Q&A session at the end of this presentation, 
and we will try to get to all the questions. If we don't get to all of the questions or if any pop up after the 
session, you can also email those in at onelab@cdc.gov. 
You will see a link that pops up in the chat now for live captions. If you need to use live captions today, 
we'll have them available throughout the entirety of the session. Please just make sure you have this 
Zoom portal pulled up as well as that live captions link. 
So let's go ahead and take a look at our agenda for the day. We're going to start with just introducing a 
new OneLab resource for you and go through today's presenters. Then we will go into our main 
presentation and finish out that Q&A that I mentioned earlier. We'll have a couple of closing remarks 
before we close out, and that's when we will also give you the information for obtaining PACE credit for 
today's session. 
So I will now be turning it over to our OneLab Network lead, Alicia Branch, to share some of our new and 
relevant resources and introduce us to our speakers. Alicia? 
Thanks, Chelsea. As Chelsea said, I want to take a moment to introduce you to some new CDC Onelab 
REACH training courses. Hold on. Hold on, Chelsea. I actually don't have anything for-- I have the wrong 
thing pulled up. Hold on just one second. 
I think we'll just introduce the Partner Toolkit. 
Think Alicia might be having some Wi-Fi technical issues today. But we are going to introduce you the 
OneLab Partner Toolkit. So it's now updated with all OneLab elements. You'll see a link dropped in the 
chat for that. And so what's in the toolkit, it's email templates, social media texts and images, postcard, 
and blog posts. 
And we invite you to use the customizable materials in the toolkit to tailor and share information about 
these resources with your networks. So you can go into the link in the chat and download and share 
those materials today. So, Alicia, if you're there, we'll go into the disclaimer slide. 
Can you hear me? 
Yes, I can hear you. Yes. 
Sorry about that. Yes, I'll go through two disclaimers and then introduce our speaker for today. The slides 
may contain presentation material from panelists who are not affiliated with CDC. The presentation 
content from external panelists may not necessarily reflect CDC'S official position on the topics covered. 
Next one. CDC, our planners, and our presenters wish to disclose that we have no financial interest or 
other relationships with the manufacturers of commercial products, suppliers of commercial services, or 
commercial supporters. 
And I am pleased today to introduce-- we actually have two speakers. The first speaker is Dr. Lisa 
Speiser. She's an infectious disease physician at the Mayo Clinic in Arizona and the Medical Director of 
Infection Prevention and Control. Her areas of interest include emerging infectious diseases and hospital 

acquired infections. 
Our second speaker is Dr. Erin Graf. She is an associate professor and co-director of microbiology at the 
Mayo Clinic in Arizona. Erin is a board-certified medical microbiologist. Her research interests include the 
application of next-generation sequencing, genetics, diagnostic and epidemiology investigations, as well 
as emerging rapid diagnostics technologies paired with diagnostic stewardships. Our speakers for today 
is, again, Dr. Lisa Speiser and Dr. Erin Graf. 
All right, good morning, and I'm just going to go ahead and share my screen here. And you can hear me 
OK? 
Yes, we can. 
Perfect. Thank you, and you can see my slides. Wonderful. Well, good morning. Thank you for having 
me. It's an honor to be here. I'm here today to talk to you about how clinical and public health laboratory 
professionals should plan for possible Burkholderia pseudomallei exposure and cases. I am Dr. Lisa 
Speiser. And with me today, I have my associate, Dr. Erin Graf. We'll go ahead and get started. 
All right, so throughout this talk, you'll learn to identify the growth characteristics, discuss standardized 
laboratory tests used to isolate and identify, as well as recognize the challenges of identifying 
Burkholderia pseudomallei. We'll define the high risk versus low risk of an exposure and the frequency of 
laboratory-acquired melioidosis. We'll also explain the indication for Post-Exposure Prophylaxis, or PEP, 
and its efficacy. We have no financial disclosures. 
So to start off with a little bit of a background, Burkholderia pseudomallei is an aerobic, gram-negative, 
rod-shaped bacterium commonly found in surface waters and muddy soils. It is transmitted primarily 
through direct inoculation with contaminated soil and water, particularly with skin abrasions. However, 
during the rainy seasons, the primary mode of transmission shifts from inoculation to inhalation. Ingestion 
of contaminated water, soil, contaminated food can also occur. 
Melioidosis has a high risk of mortality, even when we're able to diagnose and treat it, and an even higher 
risk if it's left undiagnosed. The case fatality rate ranges anywhere between 10% to 40%. 
Burkholderia pseudomallei is found in tropical climates and endemic to Asia, Australia, South America, 
and the Caribbean, with the majority of cases in Northern Australia and Thailand. However, as we learn 
more, we are discovering uncovered reservoirs throughout the world which make the boundaries of 
Burkholderia pseudomallei endemicity less clear. 
Around a dozen cases are identified each year in the United States and have primarily been identified in 
travelers and immigrants from endemic regions. However, between March and July of 2021, the CDC 
confirmed four linked cases with two deaths of melioidosis in patients from Georgia, Kansas, Minnesota, 
and Texas. None of these patients had traveled to endemic regions. And based on whole-genome 
sequencing, this strain commonly came from South Asia. It was ultimately linked to aromatherapy spray 
sold at Walmart stores between February and October of 2021. 
Burkholderia was also recently discovered in the environment along the Gulf Coast of Mississippi in the 
US around the homes of two unrelated residents who developed melioidosis. One was in 2020, and one 
was in 2022. 
Although healthy people may get melioidosis, underlying medical conditions may increase the risk of 
disease. The major risk factors are diabetes, underlying structural lung disease, liver disease, chronic 
renal disease, thalassemia, immunosuppression, or malignancy. The incubation period ranges anywhere 
from 1 to 21 days, with a mean of 4 to 9 days. However, latent infections can reactivate after years. 
The most common clinical manifestation of acute infection is pneumonia. Other sites of infection include 
skin and soft tissue, as well as the genitourinary tract. Bacteremic spread of the organism can result in 
clinical manifestations involving virtually any site. Over half of all patients are bacteremic, and up to a 
quarter can present with septic shock. Overall, mortality from melioidosis, again, ranges from less than 
10% to over 40%. 
Those with symptoms greater than two months are considered to have chronic infections, of which the 
majority present with chronic pulmonary symptoms and signs that may mimic tuberculosis, or with a 
nonhealing skin ulcer or abscess. Chronic infection is more indolent than acute, and it's associated with a 
6.5-times-lower mortality rate. 
Infection can also be latent, with subsequent activation analogous to tuberculosis. The longest reportedly 
latent period between exposure and development of melioidosis in a nonendemic region was 29 years. I'll 
turn it over to Dr. Graf. 
Right. Due to some technical difficulties, I get to present from Dr. Speiser's office, so bear with me as I get 
myself situated here. So hopefully, you got some excellent background from her on why this is such a 
serious infection and why it's really so important to the laboratory to be aware of the potential 
consequences of this pathogen. And also, the increase in cases, both through sources external to the 
United States but also sources local to the United States-- just awareness as this may become a more 
frequent laboratory infection. 
So I'm going to take you on a bit of a story of what transpired within our laboratory here at Mayo Clinic in 
Arizona and our lessons learned that apply, not only to this particular pathogen, but some of the other 
really high-consequence laboratory exposure pathogens, including select agents. 
So this is kind of the backstory of our exposure. This was a patient who had a specimen collected in the 
OR. It was sourced as an aortic tissue but also had a swab sent from what was sourced as an abscess. 
And that was received in the laboratory and plated for routine cultures. 
It hit this weird time point where it was too young to be worked up on the day shift. And so it was 
subcultured and waited for appropriate workup the next day. We don't read cultures around the clock here 
and work them up around the clock. So that was part of the issue. 
So at that time point, it was just a little bit before 18 hours. It was noted to have light growth, very tiny 
colonies, pinpoint colonies. And so I'll give an image of that here. This is not our actual image. This is 
one, I think, that is from the literature. But you can imagine it looked just like this at 18 hours. So it was 
pinpoint growth on both sheep blood and chocolate agars, and then even less growth on the MacConkey 
agar pictured there. 
The technologist at the time really thought it was going to be a Pseudomonas. Whether it was a 
Pseudomonas aeruginosa, that was a weak-growing variant versus a nonaeruginosa Pseudomonas. That 
was really what she thought she was seeing on those plates, again, before 18 hours. 
So the organism was placed onto MALDI with this assumption. So we used MALDI-TOF, as most labs do, 
for identification. And we use the clinical side of it, the FDA-approved side of it, not the research-use-only 
side. 
However, I think at that point, she had no results and then pivoted over to the RUO side, which we 
sometimes do. Even though it's not validated, it can give us a little bit of a clue as to what it might be and 
then the steps we can take to work it up further. And at that point, she got an identification of Burkholderia 
thailandensis, which should set off hairs on the back of your neck to stand up because that is a common 
overlapping ID between Burkholderia pseudomallei. So that was kind of our clue that this was potentially 
a select agent. 
So at this point, it was sent off to laboratories for them to do their work. There's a little bit more of a 
backstory to it, in that we did some basic biochemicals, and we thought we had actually ruled it out. It was 
catalase negative. And so if you read through some of the guidance on how to handle these from ASM 
and CDC and the APHL Laboratory Response Network. 
Catalase is one of the tests that you can use. Unfortunately, in this case, it was catalase negative, which, 
really, that should have been a flag to us as, stop here. Don't go further. But in theory, we thought we had 
ruled it out, so it was a little bit more complicated of a story. So we eventually sent to and so they deemed 
it Burkholderia pseudomallei. 
So unfortunately, this led to exposure to three technologists in the laboratory. And I won't go into the 
details on that because Dr. Speiser is going to cover the exposure follow-up. But this was such a huge 
deal for our laboratory to have this exposure. We took it extremely seriously. And so as I said, Dr. Speiser 
will go into the prophylaxis and the serologic monitoring next. 
But we did a risk assessment on some of our workflow processes. And this was done institutionally. So 
this was beyond lab. This was to the highest levels of Mayo Clinic. This was such a big deal, and it was 
so serious. 
And so I want to just give a quick shout out because these slides are largely all borrowed from Jessica 
Larsen, who's our laboratory supervisor now. At the time, she was the lead technologist, and she was 
fortunate enough to present all of this data at the ASCLS annual meeting last year. So I just want to make 
sure I give her shout outs throughout this talk. 
So as a result of some of the risk assessment that was performed, of course, one of the knee-jerk 
reactions is to go and update your SOPs. Are our SOPs robust enough? Did they have enough detail on 
how to suspect a select agent and how to rule something in or out or what the steps are to do? 
So it's clear in this case-- and these were some pretty seasoned and senior technologists who 
manipulated this culture. It was clear to us that there just globally wasn't a ability to recognize these as 
potential select agents. So we modified our SOPs. We added a lot more detail and verbiage around and 
some images around what to look for. 
But in the end, we realized that just updating SOPs and then reminding folks at huddle to read the SOPs 
and sign off that they read the changes is just simply not good enough. So we know this because we 
performed some competencies. So we did some fake test patient, select agent mimics. And then we 
participate in the College of American Pathologists Laboratory Preparedness exercises, which is meant to 
test this exact system. Their select agent mimics, or Pseudomallei can be one of the mimics. 
And so we failed miserably. We had actually six new potential exposures. They weren't real exposures 
because these were all fake mimic of a potential select agent. But that just brought awareness to the fact 
that simply updating SOPs is not good enough. So we realized we really needed to do something 
different. 
So I already gave a shout out to Jessica Larsen, but the rest of the team, Dr. Thomas Grys, who's my 
codirector, Barb Harris and who are supervisors for the laboratory, Jake Karsten, our safety officer, Joyce 
Lau, our chief team lead-- we all came together and said, we have to do something different. There's 
something wrong here, and we can't sleep at night with the potential for another exposure. 
So we approached it in a quality framework. And so the first thing we did was sit together. And I'll say this 
happened kind of rapidly and ad hoc. It was not as formalized as this drawing makes it seem to be. But 
we were able to go back later and map this out in a visual way. But we went through every step of our 
laboratory processes, all the steps that happened from plating to culture reading. 
And so, again, this is the work of Jessica Larsen. You can see pictured here, the steps that are in the 
purple boxes are the processing steps. And then the blue boxes and circles are the reading steps of 
things. 
And so that's really where the plate manipulation happens on the benchtop. We do all of our processing 
and our plating inside a biosafety cabinet. So we felt like our processing team was really safe. But it's 
totally impractical to think about reading every single culture inside a biosafety cabinet. So we needed to 
find ways to do this kind of work safely when it's happening on the open benchtop. 
And so we, again, honed in on the steps where the actual exposures occurred. So that visual inspection 
of plates-- if you're a microbiologist, you're used to pulling out your stacks and stacks of plates. And then 
you're just flipping through them one at a time, usually just immediately taking that lid off the plate and 
visually looking at what's going on the agar. So, boom, that's already an exposure in a sense because 
you're opening it up into the air. So that was one of the things we honed in on. 
And then the biochemical testing and the identification on MALDI-TOF are big potentials for 
aerosolization. So when we're doing things like an oxidase or catalase, those are highly aerosol, 
especially the catalase. I'll get to that in a bit-- highly aerosol generating. And then MALDI as well, doing 
that outside the biosafety cabinet has a potential risk of exposure. And then setting up your McFarland for 
susceptibility testing-- that's usually done in an open tube, and you're vortexing it, so high potential for 
aerosol exposure there. 
So we had a discussion around, OK, these are our high-point steps that we need to change the way that 
we do the work that we do. And what are some steps we can take to change the way we handle things? 
And so we did an impact-effort matrix, where we talked through some of the things that we could use as 
solutions. 
So as I said at the beginning, one theory that actually came to us with was, well, we can buy you some 
more biosafety cabinets. Will that help you, if you can do all of your work inside a biosafety cabinet? I 
think anyone listening that's a microbiologist realizes that's just simply not practical. With the volume of 
cultures that we handle, we can't do all of that work inside a BSC. So that was kind of a high-impact 
potential, but the effort required to implement was extremely high. 
We could purchase lab automation to screen our culture plates. And I'm going to come back to that at the 
end because that's actually something we ended up doing. And we thought it would have high impact. But 
in the end, it actually doesn't. So we'll come back to that. 
What we kind of hovered around was the potential to keep the lid on for visuals-first inspection. So if we 
can retrain our techs to say, all right, I'm not just going to flip that plate and open it up and have a look the 
way that I'm used to doing. If I'm just going to keep that lid on for that very first look and if I can visually 
rule out a select agent, then I'm safe to go back to my usual workflow. 
We could also tape all the plates to enforce that folks don't open the lid to begin with, but that just became 
completely impractical. And actually, taping and parafilming plates leads to contamination. We could put 
bright labels on all the plates as a reminder maybe based on specific sources, like an abscess or a 
respiratory source. But in the end, we felt like that would have extremely low impact on the situation. 
People would just start to ignore it. 
And then, really, the primary goal of this was to take the lid-on method, so keeping the lids on the plates, 
and then put that into an education module to modify that workflow. And sometimes fear can be a really 
important factor in behavior changes, so putting in some scary real-life consequences to that education 
module. And so, again, a shout out to Jessica Larsen and then our education specialists who were the 
drivers of this education module. 
All right, so I'll move ahead and say that, again, we're focusing on this lid-on method to avoid that first 
step in potential exposure. And then we really don't have to worry about the subsequent steps. So we're 
probably overly conservative, and that was OK with us. We wanted to intervene at that moment of first 
opening the plate. And then if we can't rule out a select agent, we're not going to move forward with those 
potential other steps of risk, the biochemical testing and the MALDI-TOF. 
All right, so just to show you a few screenshots of this education module-- and I'm going to give you a link 
in a little bit because this is actually accessible to everyone. So again, we approached this from the angle 
of being as conservative as possible. We wanted to make sure that if there was a potential select agent, 
we stopped before any further potential for exposure, so stopping before we did biochemical, stopping 
before we potentially did MALDI-TOF. We never wanted something to get on to MALDI and then realize, 
shoot, we didn't rule something out. So, again, probably overly conservative, but that was OK to us. 
So here are a few images that are describing some of the old workflows versus the new workflows, again, 
just focusing on keeping the lid on the plate as we're examining the plates and then the features to look 
for, so that pinpoint growth on the chocolate and sheep blood agars. 
And so this module, it walks you through potential scenarios. And it lets you pick and decide how you're 
going to handle something. So it has these features that are consistent with Burkholderia pseudomallei. 
And what are you going to do with it? Are you going to-- what biochemicals are you going to perform? 
And then at what point are you going to intervene with the state public health laboratory? 
And so one of the fun things that they put on here was how a catalase test works. So you can see here is 
an isolate that is run on a catalase test. And you can see the aerosolization that takes place in the culture 
growth. And then here's showing the method of keeping the lid on the plate. That went through really fast, 
so I'll play that-- see if I can go back and play that one more time for you. 
But, yeah, here, you can see the catalase test is resulting in growth on that plate sitting on top, showing 
you how it actually aerosolizes and then creates an exposure for you as the individual. And then there's 
the keeping the lid on and investigating the plate. So again, major shout out to and Jessica Larsen and all 
the individuals who helped with that. 
So to make it even more fun, Jessica and created a choose-your-own-adventure method here. So you 
could basically get to pick the path that you go down. And there used to be books that did this. And now 
you can actually do this on Netflix and other systems, where you can choose where the characters go or 
where the story goes. 
So you can do that with culture plates. You can decide, are you safe to work this up on the benchtop? Or 
are you going to go into the biosafety cabinet? So you get to choose your own adventure there. And if you 
choose the wrong thing, it might tell you, oop, incorrect. Now you've accidentally exposed your coworkers 
and yourself, and here are some steps that are going to happen and some fun things about, here's how 
different antibiotics can have an impact on you. 
We all think, OK, I had an exposure. I'm just going to take a course of antibiotics. I'll be fine. But there's 
some nasty side effects. Dr. Speiser can speak to that in a little bit. So we never want to get to that point 
of just saying, well, it's OK. I had an exposure. I'll just take some prophylaxis. It's really not trivial. 
And so it gives further explanation and guidance. If you get something wrong, it doesn't just leave you 
there with, hey, you're wrong. This happened. It gives you some guidance and explanation behind that. 
And so it gives you a score at the end as well. And so you can go back and redo some of the scenarios. If 
there's one that you're really struggling with and you need to keep going back and going through it, it 
gives you that opportunity. Yeah, so ultimately, it likes to remind you, you must live with your choices. So 
again, that exposure to yourself and to your laboratory coworkers, really hammering home a little bit of 
that fear, change motivation. 
So here is the website for the module. I think they're going to paste it as well in the chat or the Q&A box. 
And so, again, just a shout out to the content creators. They're amazing people at Mayo Clinic. 
So Jessica's goal with this was to not only have everyone take that module and complete that module, but 
then to actually see what kind of changes came into place as a result of that module. So she and her 
team sent out fake patients. So we tried to mask these as best we could as fake patients. It's actually 
hard to do in the system. 
But we created fake patients and sent them out and tested the tech's ability to recognize them as a select 
agent. So did they recognize with the lid on that there was a suspicious growth and then immediately 
bring it into the biosafety cabinet, consult the director on service during rounds, and then, if necessary, 
refer to
So 100% success rate, 10 out of 10 techs had great recognition, no potential exposures. And you can see 
here the different organisms that we threw at them. They're all pretty much mimics of Burkholderia 
pseudomallei. That was really our focus at the time because of that exposure. So we were really proud of 
the work that the team did on this. Yep, and so 100% worked up in the BSC, 100% director on service 
notified. 
So we also monitored our real-time clinical isolates, so meaning we got an isolate through an actual 
patient. And there was concern that it was a potential select agent, again, mostly focused around 
pseudomallei. What did we end up finding when we sent it to
So I will say, this is a really important partnership, and we're lucky to have a great team here in Arizona. 
And so I encourage those who are listening to really interact with your either local or state public health 
laboratories around this topic because what happened was after the module, our rate of submission of 
isolates to them for rule out dramatically increased. And they came back to us and said, hey, what's going 
on? Y'all never used to send anything, and all of a sudden, we're getting a couple a week, maybe one a 
month. Is there something we can do to help you rule these out faster? 
So we talked to them about what we had available on site. So for those of you that use MALDI-TOF, 
you're probably familiar with reducing a lot of your biochemicals. So we don't have urea slants, for 
example, anymore. We don't really use them for anything. So we had to talk through with the state lab 
what we have access to and what we don't have access to and what is reasonable to bring in. If we're 
only going to use it once in a blue moon, things like a colistin disk, that's just not something we maintain 
in the laboratory. 
So in the end, they were fine with it. Once they understood the backstory and once they understood what 
our goals were, they were actually fine with doing all of this work. 
And so here, you can see the spectrum of organisms that we sent, where we couldn't rule out a select 
agent. We couldn't rule out Burkholderia pseudomallei specifically. So it's a range of different bugs. It's 
not one particular. So it's lots of small, gram-negative bacilli. In the case of Pseudomonas species, those 
can be really tricky. 
But we also had some Pseudomonas aeruginosa that tricked us that were really pinpoint growers, maybe 
weren't growing well on Mac, tiny on the gram stain, so just to show the point of, it's not one thing that's 
going to cause you to be concerned. It's a variety of different organisms that might raise concern. 
So as I said, one of our potential solutions was to implement automation. And we were really excited 
about the safety that might come along with having a completely closed system. So here, one of our lead 
technologists, and Felicia Rice, our technical specialists they're doing the first digital read of cultures on 
this system. And right here, he's just reading things digitally and making decisions about them without 
even manipulating the plates. And then if it needs a MALDI ID or further workup, he's pulling that off the 
line and the carousel here. 
So we thought, OK, this is great. We're going to digitally see these things. Our Spidey senses are going to 
go off. That is a potential select agent. And then we'll be able to safely work with it from there. 
Well, not so much the case. So I'm going to show you one image here. I grabbed a second one, but I 
didn't get to put it in. But we had two recent-- I don't want to call them failures, because they think that's 
unfair, but two instances of lack of recognition. 
So the first one on the left here, I bet many of you can guess what that is. This was actually a Laboratory 
Preparedness Exercise that has already been created and all of that. So I can share that openly. This is 
an attenuated strain of Bacillus anthracis. And it really has the classic morphology of the ground-glass 
colonies, no hemolysis. And then you can see these Medusa-head projections more prominently on the 
chocolate side. 
So with the system, or with our automation system, we've moved to these chocolate sheep blood And 
that's really to save space on the incubator and to speed the imaging. But that comes with some 
consequences too because we're no longer routinely plating a MacConkey with everything. 
So the other image I was going to show you-- you'll just have to picture it in your mind-- looked just like 
the Burkholderia pseudomallei pinpoint growth on both the chocolate and the sheep blood sides of the 
agar but no MacConkey to compare it to. And that technologist validly thought, well, this looks like a 

coag-negative staph to me-- we get pinpoint coag-negative staph sometimes-- and was ready to pull it off the 
automation line in just like this plate here on the left. 
So it really brought some awareness to us that the sustained safety requires constant probing and testing 
of the system. So we sent out additional fake patients for our techs to recognize. And fortunately or 
unfortunately, word kind of got around, and our ability to hide them as fake patients was a bit uncovered. 
So we didn't really get to robustly test the system the way that we wanted to. But at least the 
hyperawareness is kind of reminded. 
So I think that's where we're at right now in this cycle of how frequently do we need to do this kind of fake 
patient testing, just to keep this front and center in people's minds, because our likelihood of seeing an 
actual pseudomallei-- while extremely low, we never want someone to miss that recognition or that first 
moment of realizing that this is something concerning. 
All right, so again, one huge shout out to all of the microbiology team for participating in all of this. And 
then I'm going to turn it back over to Dr. Speiser. 
All right, thank you, for that. That was fantastic. All right, so I'm going to go over the risk assessment and 
exposure evaluation. So risk factors associated with Burkholderia pseudomallei in laboratory work are 
listed here. Exposure to aerosols represents the greatest biohazard because it can result in inhalation, 
ingestion, and mucous membrane contact. The same risk factors for naturally acquired infection are also 
used for the risk assessment of laboratory staff. 
If there is planned work with Burkholderia pseudomallei, baseline serum samples should be obtained 
from all workers and logged and stored at negative 80 degrees Celsius in a secure location. And these 
are only to be tested in the event of an exposure. Staff with risk factors for melioidosis should also be 
informed of their increased risk. And it should be formally explained and documented, and alternative 
work options should be discussed and provided when requested. In addition to standard precautions, any 
staff member who is working with this agent with identified risk factors should also be investigated for 
infection if they have a febrile illness. 
So immediately following an exposure with Burkholderia, the site of contamination or inoculation should 
be washed thoroughly. And the designated safety officer for the lab should be notified. Again, high-risk 
exposure includes inhalation, inoculation, or aerosols into the eye, but all exposure should be evaluated. 
After exposure, either the supervisor or staff member should describe the species and susceptibility 
pattern, as well as the type of exposure. The exposed staff member should be interviewed regarding drug 
allergies and current health status, including risk factors for melioidosis. They should also be placed into 
either a high-risk or a low-risk category. 
So human data is lacking for Post-Exposure Prophylaxis, or PEP. In animal models, post-exposure 
prophylaxis has been shown to effectively prevent acute melioidosis if it's administered within 24 hours of 
exposure. However, it does fail to prevent latent or persistent infection. Nonetheless, consensus 
recommendations are to offer post-exposure prophylaxis to all employees with high- and low-risk 
incidents regardless of the predisposing risk for melioidosis. And a discussion around the risks of PEP 
should be balanced against the risk of infection in any given incident. 
So the recommendations are based on treatment efficacy of naturally acquired melioidosis. If susceptible 
to trimethoprim/sulfamethoxazole, and there's no allergy, then trim/sulfate is the first choice for PEP. If 
there is resistance or the patient is intolerant, the next best choice is doxycycline or amoxicillin/clavulanic. 
Doxycycline has been used in laboratory exposure and, in experimental mouse models, has been found 
to be more effective than amox/clav for PEP. However, the data for treatment favors 
amoxicillin/clavulanic. Doxycycline monotherapy is associated with higher rates of relapse and treatment 
failure compared to conventional oral combinations. Based on expert consensus and the incubation 
period, three weeks of PEP is recommended. Fluoroquinolone should not be used for PEP because their 
use in treatment of melioidosis is associated with a high failure rate. 
Once an isolate has been identified in the lab, susceptibility should be obtained. Meropenem and 
ceftazidime are used in the treatment of melioidosis. Trimethoprim/sulfamethoxazole, doxycycline, and 
amoxicillin/clavulanate, as I had just discussed, are used for PEP. The information should be held in a 
record and immediately available to safety and medical staff after an exposure event. 
Particularly important is when working with isolates from Asia because approximately 13% of Thai 
isolates are resistant to trim/sulfa. Trimethoprim/sulfamethoxazole should be tested by eTest or another 
reliable MIC-based method, as this testing to determine susceptibility of Burkholderia pseudomallei is 
unreliable and should not be used. 
Proposed exposure-monitoring staff members should self-record their temperature twice daily for 21 days 
and report any fever, cough, or inflammation at the site of known inoculation. This should prompt further 
investigation with blood, sputum, and urine cultures. 
A sample of serum should also be taken on the day of exposure, as well as at weeks 1, 2, 4, and 6, and 
tested for the presence of antibodies. Those who come from or reside in an endemic region may already 
have antibodies. There is no evidence to guide the interpretation of a series of titers after exposure. 
However, a rise in titer is likely to indicate a new exposure. 
Based on expert consensus, if a worker seroconverts after laboratory exposure, further clinical evaluation 
and extended course of antimicrobial drug treatment is recommended. In persons who seroconvert but 
remain asymptomatic and culture negative, the PEP agent should be continued for a total of 12 weeks. 
So laboratory-acquired melioidosis is extremely rare. There have only been two reported cases prior to 
1981 in the United States. The first case, in 1966, was a bacteriologist studying Burkholderia 
pseudomallei, who acquired infection after her centrifuge developed a leak. And the concentrated 
suspension of organisms sprayed all over the walls and benches in her lab. She then used her bare 
hands to clean up the mixture of the media and organisms and then developed an ulcerative lesion at the 
base of her right index finger. This was followed three days later by chills, fever, malaise, as well as 
tender lymphadenopathy and pleuritic chest pain. 
The second case occurred in 1980 in a lab tech who aerosolized blood and sputum specimens taken 
from a 29-year-old Vietnam vet with recurrent cavitary pneumonia. This was done outside of the biologic 
safety hood in an open-flask system. 
And that is all we have. Thank you so much. I'm going to stop sharing my screen. Oh, thanks. 
Thank you. I'll see if my internet will stay connected. We'll go ahead and take some questions. If we do 
not get to answer your question during our Q&A session and if you have not submitted your question 
anonymously, we will do our best to respond via email after today's event. If you have any questions after 
today, please feel free to email the OneLab inbox at onelab@cdc.gov. 
OK, we have about 15 questions. And I will start with the first one. "Could you repeat the results from the 
MALDI RUO library?" 
No. So again, our goal is to ensure-- Sorry, a little bit of cough going on. Our goal is to ensure that we are 
never going to MALDI-- thank you-- never going to MALDI because of that potential exposure. 
So we had some discussions around-- one of the suggestions was to bring in the-- I think CDC has a 
library, a select agent library, which contains spectra for pseudomallei. For us, that was not a direction we 
wanted to go. First of all, we wouldn't ever be able to validate that. And second of all, even formic acid 
extraction or ethanol-based extraction, not so much for pseudomallei, but for anthracis, has been shown 
to be not 100% effective at killing that potential select agent. 
So again, for us, our view was we want to stop at the point of recognition and never get to the point of 
doing MALDI. So validating all of that type of library, I think for our reference laboratory, where maybe 
you're handling gazillions of isolates-- it could make sense for a reference laboratory to have that clue or 
to have that information. But for a laboratory like ours, we never want to get to the point of MALDI. So, 
yeah, once we got that ID, we wouldn't repeat it because we would never want to lead to an additional 
exposure. 
I'll go ahead and ask this one. So for your MALDI, your results, did you upload the isolates to the micro 
net? 
I don't know what that is, so I'll have to educate myself on that. We use the, as I said, the FDA-clear side 
of the Bruker library, but then we did run it on the RUO side. So I'm not familiar with pulling that spectra 
off and then uploading it. I guess we might still have that file saved somewhere, and we might be able to 
do that, but I'm not familiar with that. So thanks, I'll have to look that up. 
OK. We can actually probably share information with you. 
Great. 
This one is probably for the Dr. Speiser. So what constituted the exposure of the three lab techs? 
Yes, that's a great question. So we had three exposures, one that was high risk, in which laboratory 
technician had prepared the specimen outside of the BSC, essentially aerosolizing the contents in 
preparing it, also with underlying risk factors for melioidosis. So that was our high-risk exposure. 
The other two, which, after discussion with our local health department, had opened the plates outside of 
BSC as well. There was some question if the plates had been sniffed or not. But essentially, those had 
constituted low-risk per our local health department. 
Well, this is a good segue into this next question. "Does wearing a surgical mask minimize the exposure 
risk when reading plates?" 
Certainly, yes. So that was also something because, at this time, we were still universally masking for 
COVID-19. So certainly, that's an excellent question because people were wearing surgical masks when 
they were analyzing these specimens. And so I believe, in these cases, that one high risk and those two 
low risk were also wearing surgical masks in those instances. But nonetheless, we still consider them to 
be high risk and to low risk and then had discussion with post-exposure prophylaxis for all three of them. 
OK. Condensation on the plate would not allow for visible examination of the plate. How can we handle 
that aspect? 
Yeah, that's exactly why that taped plate idea or the parafilm-sealed plate idea was kind of a no-go for us, 
because that is what can lead to a lot of condensation. Honestly, it hasn't been an issue for us. So I would 
argue that if you are examining your routine bacterial cultures in 18 hours or even 48 hours, because 
some of these take that long to grow, and you have significant condensation, I would check your system 
there, because you really shouldn't have significant condensation without having taped plates. 
Like, that happens in mycology when all the plates are taped. And you have to tape the plate and tap it 
down to eliminate some of that moisture. But, yeah, that shouldn't be happening in your routine cultures. 
This is a good one also. "Is there anything that the physician should do in looking to alert the lab of a 
possible case?" 
Absolutely. So if there's a clinical concern for Burkholderia, so if a patient has a history of coming from an 
endemic region or traveling to an endemic region-- which, again, it goes into-- there's a lot of uncovered 
reservoirs that we're finding more and more. We felt initially that there was no Burkholderia in the United 
States, but that turns out to not be true because now we're detecting Burkholderia in the United States 
and having increased number of cases. 
But if someone has a clinical concern for either epidemiologic risk for melioidosis or a clinical syndrome 
that's concerning for melioidosis, then they should certainly be alerting the laboratory staff. And so it's a 
little bit more challenging because we're not considered an endemic region. So we don't think about it as 
much, which is why we want to start educating clinicians as well as laboratories that this is something to 
start thinking about when you are seeing these patients. 
OK, we'll take a couple of more questions. This one says, "The lid on the process seems on the surface to 
reduce the chance of aerosol exposure. Do you have any objective data with controlling experiments? We 
have completely ruled out a no-chance of aerosolization, even when plates are moved around and 
handled on the bench, even with the lid on." 
Yeah, good question. No, we don't have any objective data to prove that. Yeah, it's more of just a, I 
guess, educated assumption that not opening that plate and not sticking your face into it. And, for the 
record, sniffing is not a thing anymore, but I know that gets referenced a lot, and sometimes we use it for 
teaching purposes. 
But just opening that plate, I think it's more the potential that, in that moment of opening, it may not be an 
exposure, but should you drop, it, should something happen, it's now open and available to be inhaled. 
But with the lid on, I see your point. Like, if you're jostling plates around, that seal is not 100% airtight. 
I don't know. Do you have any thoughts on that, Dr. Speiser? 
No. Yeah, I think I'd agree with what you just said. 
Sounds like graduate student project. 
Amen, exactly. Yes, yes. 
I think the rest of the questions, we'll send them to you all after the presentation. And we can have you 
answer them offline, and then we can send them out to the participants. 
Sounds good. Excellent. 
Thank you again for joining. I know I kind of reached out to you cold turkey, so I'm so happy that you were 
able to actually join and present for us. 
Absolutely. It was a pleasure being here. Thank you so much for inviting us to come speak about this. All 
right, thank you so much. 
Thank you. 
Bye-bye. 
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And next slide, please. And, unfortunately, we had to actually change the 2023 OneLab Summit to April 
the 16th through the 18th, 2024. But what I'm happy to announce is that we actually moved it to the 
Medical Laboratory Professionals Week, or better known for laboratory professionals as Lab Week. So I 
am happy that we were able to move it actually to the Lab Week so that we can celebrate our medical 
laboratory professionals. 
We encourage attendees to continue submitting posters for the Virtual Exhibit Hall. And anyone who's 
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