There are often new buzzwords flying around that everyone uses, but few actually understand what they mean. Personalized and precision medicine are two of these terms that are often used interchangeably. Every lab wants to say they are performing personalized medicine. And to be fair we really do all provide personalized medicine in some form. Almost all lab results are used to customize the treatment for patients. However these buzzwords are used to refer to tests that describe linking genetic, lifestyle, or environmental information with predicted response to treatment. Precision medicine may be the more accurate term to describe identifying effective treatment for the right patient at the right time based on genetic, lifestyle, or environmental information. The term personalized medicine may give the false impression that therapies were developed specifically for the patient, when really they are developed to target a specific genotype or phenotype.
One example of precision medicine being used clinically today
is in oncology. Many cancer drugs now require an associated test to determine
the presence or absence of a specific biomarker to determine which patients are
likely respond to the therapy. The biomarker tests that are linked to a
specific therapy are called companion diagnostics. Biomarkers analyzed can be a
specific protein or gene such as programmed death ligand-1 (PD-L1) or epidermal growth factor receptor (EGFR) or they can be much broader such
as tumor mutational burden (TMB) or immune signatures. Identifying biomarkers that
determine which patients are likely to respond to therapy and only giving
patients with the biomarker the drug increases response rates to the therapy
and may decrease side effects. More than half of the clinical trials for cancer
drugs in 2018 were linked to a specific biomarker. Linking drug selection with
specific laboratory tests is causing an increased need for multidisciplinary
collaboration among pathology, oncology, and the laboratory.
In our lab we perform precision medicine using PCR or NGS
assays to analyze patient’s tumor for specific genes. Although we still perform
single gene testing when ordered, most of our cases are analyzed by a NGS
panel. NGS panel testing allows us to look at numerous biomarkers with one
test. This decreases the cost, time and tissue utilized to determine the
patient’s biomarker status. Our NGS panel analyzes 52 genes to look for
mutations that would indicate a patient is likely to respond to a targeted
therapy. Most of our oncology testing is done on lung, colon, and melanoma
specimens, although the panel is validated for most solid tumors. The report
that we issue the oncologist provides clear information on which therapies the
patient is likely to respond to or likely to be resistant to based on their
tumor’s genetic profile. We also include information in the report to match
patients to clinical trials. Precision medicine utilizing panel NGS testing for
predicted response to treatment is becoming standard of care for many solid
-Tabetha Sundin, PhD, HCLD (ABB), MB (ASCP)CM, has over 10 years of laboratory experience in clinical molecular diagnostics including oncology, genetics, and infectious diseases. She is the Scientific Director of Molecular Diagnostics and Serology at Sentara Healthcare. Dr. Sundin holds appointments as Adjunct Associate Professor at Old Dominion University and Assistant Professor at Eastern Virginia Medical School and is involved with numerous efforts to support the molecular diagnostics field.
A 65 year
old man with diabetes mellitus type 2 presented to the emergency department
(ED) for left hip pain. He has a remote history of avascular necrosis of
bilateral hips of unknown etiology for which he received a bilateral total hip
arthroplasty and subsequent multiple revisions due to hardware failure several
years ago. He initially presented to an urgent care clinic a few months prior
for “noise with movement” of the left hip and mild lower back pain. Plain radiographs
of the left hip in comparison to his prior imaging were unremarkable and he was
subsequently discharged. Repeat imaging at a follow-up visit at the orthopedic
clinic showed mild superior migration of the femoral head bilaterally secondary
to periprosthetic osteolysis of
the joint headliner. He was scheduled for surgery however presented to the ED prior
to his scheduled appointment with severe crushing left hip pain and restricted
joint mobilization. He denied fevers, chills, night sweats, or any other recent infections. The left
hip was aspirated yielding
10cc of dark
black fluid and a stat gram stain was ordered.
The stat gram stain showed many
polymononuclear cells with moderate gram positive bacilli in a background of
dark inorganic material (Image 1). Following 48 hours of incubation, there was anaerobic
growth on the kanamycin and vancomycin (KV) and schaedler agar
plates. A Gram stain of the broth showed gram positive bacilli arranged
singly and in chains with some decolorization (Image 2). The KV and schaedler plates showed moderate growth of a single
organism consisting of small glossy tan colored colonies (Images 3-4). No
aerobic growth was observed on the blood, MacConkey, Columbia Naladixic Acid (CNA),
or chocolate agar plates. Mass
spectrometry (MALDI-TOF) identified the
pathogenic organism as Clostridium innocuum.
Bacterial joint infections are more common in prosthetic joints as
compared to native joints with a prevalence of 1-2% following hip arthroplasty
(1). Most cases of bacterial septic
arthritis are due to staphylococci (40 percent),
streptococci (28 percent) or gram negative bacilli (19 percent) organisms (2). Joint
infections secondary to anaerobes are less likely and account for 2-3%
of all cases (3). A review of the literature shows less than 50 documented
cases of septic arthritis due to Clostridium species. Amongst these
cases Clostridium perfringens is the most commonly isolated pathogen (4).
To date there are no documented cases of joint infections secondary to Clostridium
Clostridium innocuum is a non-motile, anaerobic, gram positive organism
that reproduces by sporulation. These organisms are normally found as a part of
the usual human gut flora and are rarely human pathogens. The name “innocuum”
is derived from the term “innocuous” to convey the innocence of these organisms
as they do not produce clostridial exotoxins. A review of the literature shows
fewer than 20 reported cases of Clostridiuminnocuum infections
with most reported cases being described in immunocompromised patients such as
those with diabetes mellitus, chronic
hepatitis, acquired immune deficiency syndrome (AIDS), leukemia, and
organ transplantation (5-6). Clinically patients can present with a spectrum of
symptoms which include fever
of unknown origin, diarrhea/constipation, and non-specific respiratory symptoms.
In almost all cases bacteremia ensued. Most
cases were associated with a traumatic penetrating injury with few reported
cases due to hematogenous spread (5-6).
Laboratory identification of Clostridiuminnocuum can be challenging due to its variable gram staining morphology and
atypical colony morphology on differing culture media. Most traditional
phenotypic methods can only reliably identify these organisms to the genus
level as a Clostridium species. However, using mass spectrometry
(MALDI-TOF) these organisms can be identified to the species level. Rapid
identification of Clostridium innocuum from the subset of Clostridium
species is clinically important as these organisms are the only known Clostridium
species with intrinsic resistance to vancomycin (7). Although they do not
possess clostridial exotoxins, these organisms are thought to have a
lipopolysaccharide-like virulence factor and have a mortality rate comparable
to toxigenic Clostridium species (7). Due to resistance to vancomycin, metronidazole, piperacillin and ampicillin-sulbactam are the
alternative recommended first-line treatment options.
patient, following the results of the gram smear the patient was started on IV vancomycin
but due to an adverse allergic reaction was switched to intravenous pencillin G
and oral ciprofloxacin. He was subsequently taken to the operating room for
incision and drainage and left hip revision arthroplasty with cup exchange. Blood
cultures were collected post-operatively and showed no growth, possibly due earlier
antibiotic administration. Susceptibility studies from Mayo Laboratories showed
pan susceptibility to penicillin, piperacillin-tazobactam, ertapenem,
clindamycin, and metronidazole. The patient was subsequently switched to
intravenous penicillin and continued to show clinical improvement during his
remaining hospital course.
Katzap E, Horowitz S, Barilla-labarca ML. Approach to septic arthritis. Am Fam
Kavanagh R, Wall PG, Hazleman BL. Bacterial joint infections in England and
Wales: analysis of bacterial isolates over a four year period. Br J Rheumatol.
The following case is an interesting overlap of
Hematopathology and Molecular Diagnostics, and shows the utility of sequencing
to detect a cancer before biopsy could.
A 63 year old gentleman presented to a heme/onc physician
with six months of intractable anasarca, fatigue, and a recent mild
thrombocytopenia (Table 1). They were otherwise in healthy condition. The
physician initiated a lymphoma work-up that included a bone marrow biopsy. The
tests were negative for M-protein.
The bone marrow biopsy was somewhat limited, but the core contained multiple marrow elements. After a thorough review by a Hematopathologist, no evidence of dysplasia or other irregularities could be detected (Image 1). Flow cytometry detected no aberrant blast population. Cytogenetics detected 20del [16/20] and 5del [3/20]. These findings did not clearly indicate a specific diagnosis.
As the clinical suspicion for a malignancy was high, the
bone marrow specimen was sent for sequencing on a 1385-gene panel test. The
test included tumor-normal matched DNA sequencing (“tumor” sample: bone marrow,
normal: saliva), RNA whole transcriptome sequencing on the bone marrow, and
Copy Number Variant (CNV) analysis. Tumor-normal matched sequencing helps rule
out variants that are normal and present in the patient.
Somatic mutations were determined as those that were present
in the “tumor” sample and not in the matched normal sample. The somatic
variants found are listed below with their variant allele frequency (VAF) in
parenthesis. Recall that a VAF of 40% means that a mutation is present in the
heterozygous state in 80% of cells.
IDH2 (p.R140Q, 46%)
SRSF2 (p.P95T, 51%)
CBL (p.R499*, 47%)
KRAS (p.K117N, 12%)
The mutations in these genes are commonly found in myeloid
cancers including myselodysplastic syndrome. Activating mutation in IDH2 (isocitrate dehydrogenase 2)
increase the production of the oncometabolite 2-HG, which alters methylation in
cells taking them to an undiffereitiated state. SRSF2 (Serine And Arginine Rich Splicing Factor 2) is a part of the
spliceosome complex, which regulates how sister chromatids separate from each
other. Failures in the proper function of the complex creates genomic
instability. CBL (Casitas B-lineage
Lymphoma) is a negative regulator of multiple signaling pathways, and loss of
function mutations (as seen here) lead to increased growth signals through
several tyrosine kinase receptors. KRAS
(Kirsten RAt Sarcoma virus) is an upstream mediator of the RAS pathway, which
acquires mutations that lead to constitutive activation and sends growth
signals to cells causing them to proliferate.
Furthermore the CNV analysis
also found the heterozygous loss of chromosome 20 as reported in cytogenetics.
CNV analysis did not detect chromosome 5 deletion, as it was below the limit of
detection (20% for CNV analysis).
These mutations are all individually common in MDS, but the co-occurance of each gives very strong evidence that MDS is the diagnosis (Figure 3). There have also been studies that provide prognostic implications for several of the genetic mutations present. Some mutations like SRSF2 or CBL at high VAF (>10%) indicate a poor prognosis, but mutations in IDH2 or TP53 at any frequency have not only a high chance of progression, but also a faster time to onset of disease. Another non-genetic risk factor for developing MDS is an elevated RDW, which we saw in our patient.
All of these high-risk factors together led us to push for a diagnosis of MDS based off of molecular findings, and the patient was started on treatment with Azacitadine. Our assessment was confirmed 3 months later when, the patient’s follow up bone marrow biopsy showed significant progression with megakaryocytic and erythroid dysplasia and hyperplasia and reticulin fibrosis MF2 (Image 2). Aberrant blasts were detected (1-2%), but not elevated. This demonstrates how molecular findings predicted and predated the patient’s rapid progression to morphologic disease.
In summary, multiple molecular mutations indicative of MDS
were found in a symptomatic patient’s unremarkable bone marrow biopsy months
before a rapid progression to MDS.
Steensma DP, Bejar R, Jaiswal S et al. Blood 2015;126(1):9-16.
Sellar RS, Jaiswal S, and Ebert BL. Predicting progression to AML. Nature Medicine 2018; 24:904-6.
Abelson S, Collord G et al. Prediction of acute myeloid leukemia risk in healthy individuals. Nature 2018; 559:400-404.
Desai P, Mencia-Trinchant N, Savenkov O et al. Nature Medicine 2018; 24:1015-23.
Becker PM. Clonal Hematopoiesis: The Seeds of Leukemia or Innocuous Bystander? Blood.2016 13(1)
-Jeff SoRelle, MD is a Chief Resident of Pathology at the
University of Texas Southwestern Medical Center in Dallas, TX. His
clinical research interests include understanding how the lab intersects
with transgender healthcare and improving genetic variant
The majority of laboratory injuries and exposures are
preventable, and most of them occur because staff is not paying close attention
to the situation. They lose their situational awareness or were never paying
attention to it from the start. Unfortunately, lab safety professionals spend
much of their time investigating such incidents rather than being able to
prevent them. If laboratory staff could understand the power of the pause, labs
would have fewer dangerous incidents.
One illustration of that power can be seen in a simple
exercise. A group of people is asked to read aloud quickly a list of words that
indicate different colors- green, red, etc. The words themselves, however, are
written in different colors, and the colors do not match the words. For
example, the word “red” is written in black, the word “blue” is written in
green, etc. This first part goes well, you’re just asking them to read the
actual words. Next, however, it gets harder. The people are asked to quickly go
down the list again, but this time they are asked to say the color of the word,
not that actual word. Typically, this does not go well. For the next step, the
exercise is repeated at a much slower pace, with a slight pause between each
word. Once a pause is placed between each word, the people recite the correct
colors. The incongruent words and colors creates what is known as the “Stroop
Effect,” first theorized in 1935, but pausing is a means of overcoming this
issue in our brains.
When investigating a needle stick incident, the lab safety
officer learned the employee completed the draw, attempted to engage the needle
safety device, but stuck their finger when grabbing the needle to toss it into
the sharps container. She did not notice the safety device did not engage and
the needle was still exposed. The employee stated she was busy and in a hurry
because there were many other patients waiting. I have always said that when a
lab employee is stressed and busy, that’s when stopping for a moment to gain
situational awareness is most important. Had this employee paused for a moment
to ensure the needle safety device was fully engaged, the incident would never
The lab manager had to speak to a chemistry tech after a
serum splash exposure to the eyes. When looking at the work area, the manager
noticed there was an adjustable face shield in place but that staff moved it
into place only when needed. The tech admitted he was busy at the time of the
splash and that he neglected to move the shield into place before uncapping
specimens. Again, a pause to think about safety here would have helped.
In another situation, a microbiology technologist was eager
to start the day and get it done since her vacation began the next day. She
quickly went through the daily checklist and checked items off but did not
actually perform the checks. Halfway through the day, she noticed it seemed
warm and that it was unusually quiet at her biological safety cabinet work
station. She decided to look at the gauges and noticed that there was no
protective air flow in operation. She had been working with TB samples all
morning. When she reported the issue, the manager told her that all employees
in the area would need to go to Employee Health and be followed up for TB
exposures. Pausing to perform the safety checks at the beginning of the shift
would have made a big difference in that outcome for several employees.
Pausing for safety in the laboratory setting can be a
powerful tool, even during the busiest moments. In fact, that’s when it works
best. Use that pause in your arsenal, and teach maintaining situational
awareness with your staff so that future injuries and exposures can be
–Dan Scungio, MT(ASCP), SLS, CQA (ASQ) has over 25 years
experience as a certified medical technologist. Today he is the
Laboratory Safety Officer for Sentara Healthcare, a system of seven
hospitals and over 20 laboratories and draw sites in the Tidewater area
of Virginia. He is also known as Dan the Lab Safety Man, a lab safety consultant, educator, and trainer.
A man in his 40’s with a past medical history of acute
lymphoblastic leukemia/lymphoma (in remission), multiple infections including
bacteremia and pulmonary aspergillosis, presented to the hospital with fever
and diarrhea. Over the course of his stay, he had worsening renal function and
developed profound hypotension and shock, which prompted initiation of two
vasopressors and high-dose steroids. Eventually he developed acute hypoxic
respiratory failure, requiring intubation. Complete blood count demonstrated an
absolute eosinophilia of 8.58 x109/L (reference range 0.04-0.62 x109/L).
Imaging revealed bilateral pulmonary infiltrates and a pleural effusion.
Respiratory culture with gram stain was ordered for his tracheal aspirate,
which revealed few polymorphonuclear cells, many gram-negative rods, yeast, and
larvae of Strongyloides stercoralis (Image
1A). Wet mounts of the tracheal aspirate revealed numerous larvae and a few
eggs of S. stercoralis (Image 1B-C);
many of the larvae were motile (Movie 1). Stool examination of ova and
parasites (O & P) were positive for larvae. Given the burden of organisms
and prior administration of steroids, he was diagnosed with severe
strongyloidiasis, consistent with hyperinfection. Concurrent blood cultures
grew Enterococcus faecalis and Stenotrophomonas maltophilia; the
respiratory culture also grew S.
maltophilia, and tracks from the migrating larvae were observed on
respiratory culture bacterial media (Image 1D).
Strongyloidiasis is a spectrum of clinical disease caused by
the nematode Strongyloides stercoralis.1,2
Descriptions of acute infection have been described in other Lablogatory
entries here,3,4 and the full lifecycle is described in detail on
the CDC DPDx website.5
Severe strongyloidiasis includes the syndromes of
hyperinfection and disseminated disease. Hyperinfection
is when there is an elevated burden of the typical autoinfection cycle
involving the lungs and GI-tract. Usually there is an antecedent
immunosuppressive event, such as administration of corticosteroids. Within the
GI-tract lumen, increased numbers of rhabditiform larvae transform into the
infective filariform larvae, which traverse the GI mucosa, migrate to the lungs
via bloodstream/lymphatics where they enter alveolar air spaces, then ascend
the respiratory tract, and are coughed up by the host and swallowed to re-enter
the GI tract. In the GI tract adult females lay eggs through parthenogenesis,
which give rise to further rhabditiform larvae. In extreme cases of
hyperinfection, adults can be found in the lungs, where they may also lay eggs.
Finding eggs in respiratory specimens is unusual, and may be related to the
burden of disease.6
is when larvae can be found in any additional organs/organ systems, such as the
central nervous system, kidneys, liver, adrenals, etc. Invasive sampling is not
typically performed, and larvae can be observed at autopsy.
Laboratory diagnosis of S.
stercoralis involves identification of rhabditiform larvae in stool O
&P exam; the presence of adults or eggs in stool is rare. Rhabditiform
larvae have short buccal cavities and an ovoid genital primordium structure midway through the body (Movie 2).
O&P exams can be performed on other body fluids, such as sputum and CSF.
Serology can be useful to identify past exposure, especially prior to
initiating immunosuppressive therapeutics such as corticosteroids. A
nonspecific finding can be observed, as in this case, in the complete blood
cell count and differential. Relative and absolute eosinophilia can be found in
patients with parasitic infections; therefore, it is reasonable to rule out
parasitic infection in this subset of patients. In the case presented here, the
absolute eosinophilia was likely due to a persistent S. stercoralis infection, since these nematodes can live in the
human host for decades.
The treatment of choice for severe strongyloidiasis is oral
ivermectin, though albendazole is an alternative therapy. In some instances,
subcutaneous ivermectin administration may be used.7
Oral ivermectin was administered to treat the
strongyloidiasis and antibiotics were administered to treat the bacterial
infections. Over the coming days, serial tracheal aspirates continued to reveal
many larvae and eggs, so therapy was escalated to subcutaneous ivermectin. Over
the course of therapy, the patient developed a fungemia with Candida guilliermondii. Despite
aggressive antimicrobial therapy and intensive care, the patient remained
hypoxemic and hypotensive. The family decided to transition to comfort measures
and the patient passed away.
Maguire JH. Intestinal Nematodes (Roundworms), in Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, B. Mandell, Dolin, Editor. 2010, Elsevier: Philadelphia, PA. p. 3577-3586.
Parasitology, in Koneman’s Color Atlas and Textbook of Diagnostic Microbiology, Procop et al., Editors. 2017, Lippincott Williams & Wilkins: China. p. 1452-1454.
Keiser PB and Nutman TB. Strongyloides stercoralis in the Immunocompromised Population. Clin Microbiol Rev, 2004. 17(1): p. 208-17.
Hurlimann E and Keiser J, A single dose of ivermectin is sufficient for strongyloidiasis. Lancet Infect Dis, 2019. 19(11): p. 1150-1151.
-IJ Frame, MD, PhD, Microbiology Fellow, University of Texas Southwestern Dallas, Texas
-Clare McCormick-Baw, MD, PhD is an Assistant Professor of Clinical Microbiology at UT Southwestern in Dallas, Texas. he has a passion for teaching about laboratory medicine in general and the best uses of the microbiology lab in particular.
“Never, ever underestimate the importance of having fun,”
said Randy Pausch, a professor of computer science at Carnegie Mellon
University. Indeed, having fun is an important component of life, and that
includes your professional life. However, having fun in the workplace can seem
like an impossible task sometimes. There is, after all, lots of work to be
accomplished, performance to be measured, and projects to complete. This can
make it challenging to find of time and ways to have fun appropriately and
The benefits of having fun in the workplace are plentiful. Because
most fun activities require people to work in groups or teams, the shared
experience can increase collaboration, engagement, and foster communication. Having
fun fosters motivation and commitment to an organization as people associate
the positive feelings and experiences with the workplace. This also increases
morale and comradery among the participants, which increases their performance.
All these aspects, in turn, foster creativity, innovative thinking, and
problem-solving skills. The more creative employees are, the more comradery
they feel among themselves, and the better they perform the more turnover is
reduced. Having fun in the workplace is incredibly beneficial to both the
employees and the organization overall.
In today’s workplace culture, people are generally more
aware and considerate of what is appropriate behavior. This also applies to
having fun, because if activities are only fun and enjoyable if they are
appropriate for everyone involved. It is, therefore, important to establish
clear boundaries: what is considered part of this activity and what is not. It
is also important to consider different levels of physical, mental, and
emotional ability. Having fun is inclusive and collaborative, so it is critical
to design activities that everyone can partake in. The activity should also
always be optional. Making participation mandatory is not actually fun for people,
so make sure that there is an opt-in and opt-out option. Finally, every
activity should have some element of learning and education. If you are asking
people to participate in a fun activity, ensure that they are learning
something about one another or about a specific topic.
There are many different ways in which you can incorporate
fun in the workplace. Last year at ASCP, our social committee hosted an ‘Oscar
Party” in which we could vote for our colleagues in categories such as “Outside
the Box Thinker/Innovator,”, “Outstanding Philanthropist,” and “Rookie of the
Year.” Then all staff gathered in the kitchen area of our office that was
decorated with a red carpet and we all received a glass of sparkling cider. The
winners were announced and cheered on as they walked the red carpet. They gave
a short speech after receiving their little Oscar award. It was a simple way to
have some collective fun and it felt so great cheering everyone on and
recognizing certain employees for their outstanding contribution to the society.
On average, babies laugh about 400 times a day. Adults, on the other hand, only laugh about 35 times a day and significantly less often on weekdays than on weekend (Beard, 2014). Laughter is incredibly important to our overall well-being and performance. In fact, “laughter relieves stress and boredom, boosts engagement and well-being, and spurs not only creativity and collaboration but also analytic precision and productivity”(Heggie, 2018). So, let’s try to incorporate more fun and more laughter in both our personal and our professional lives. Let’s find ways to cheer each other up and create a collaborative, warm, and productive environment that fosters engagement, retention, and analytic precision. After all, laughter is the best medicine.
-Lotte Mulder, EdM, is the Senior Manager of Organizational Leadership and Patient Engagement at ASCP. She earned her Masters of Education from the Harvard Graduate School of Education in 2013, where she focused on Leadership and Group Development. After she graduated, Lotte started her own consulting company focused on establishing leadership practices in organizations, creating effective organizational structures, and interpersonal coaching. She has worked in Africa, Latin America, Asia, and the U.S. on increasing leadership skills in young adults through cultural immersion, service learning and refugee issues, and cross-cultural interpretation. She is currently working toward a PhD in Organizational Leadership.
During the 2019 ASCP Annual Meeting in Phoenix, I noticed a
morning workshop session entitled “The Impact of Fun.” The title intrigued me,
so decided to take a break from the science and clinical medicine workshops
that I would normally attend, and take advantage of the opportunity to listen
I have been working as a pathologist and lab director for 30
years, and while I hate to admit it, I had never thought seriously about taking
time during the day for playing games with my co-workers. I was always consumed
with meetings, deadlines, and getting the clinical work completed.
At the beginning of the course, I was a little unsure what I
had gotten myself into. However by the time the workshop concluded, the reality
of what I had been missing had set in.
When I returned to work following the meeting, I began to
search for fun activities that our lab team could do over a lunch hour. I set a
date and promised food to entice the wary into attending the event in the
conference room. Once they had assembled, I divided the group into two teams by
drawing an imaginary line down the middle of the room. We then played team trivia
using a book of questions I had acquired. By the end of the hour, everyone was
laughing and having fun. The lab continued to buzz with talk and occasional
laughter all afternoon.
We have continued setting aside one noon hour each month
where we gather for different types of games. Charades, and Pictionary have
been hits. Mostly everyone brings their own lunch, but food or deserts are
provided on occasion to keep these events special. There are a few who choose
not to participate, but even they occasionally show up to watch and laugh along
with the rest. As is pointed out above, you cannot make having fun a mandatory
or it ceases to be fun.
Our lab staff really seem to enjoy these events and so does
this old pathologist. During our most recent event, one of my young colleagues
remarked how much fun these lunches have been, and that they hoped we would
continue these going forward. I intend to keep these going as long as I
continue working. It has provided me with an opportunity to get to know each of
my co-workers much better. I only wish I had learned about the importance of
having fun with your co-workers and teammates earlier in my career. I encourage
other pathologists, lab directors and section supervisors to learn from my
experience and begin finding ways to bring the fun back into the workplace if
you have not already done so.
-Dr. Wisecarver is currently Professor Emeritus in the Department of Pathology/Microbiology at the University of Nebraska Medical Center in Omaha, Nebraska. He served as Medical Director of the Clinical Laboratories for Nebraska Medicine, their clinical affiliate from 1996 until 2017. He currently serves as the Director of the Histocompatibility Laboratory for Nebraska Medicine.
A 77 year old male presented to the hospital with chest
pain, lightheadedness, burning urination for the past few weeks. He has blood
in his urine due to a previously diagnosed neoplasm. The patient moved from
India to the United States in February, with a diagnosis of bladder cancer and
a history of hypertension, congestive heart failure, coronary artery disease,
and atrial fibrillation. In the hospital, abscesses on both right and left
kidneys were found, and patient had nephrostomy tubes placed. Purulent
discharge confirmed he had a severe urinary tract infection.
The patient’s urine culture grew >100,000 colony forming
units/milliliter (CFU/ml) of an oxidase-positive, non-lactose fermenting
Gram-negative rod. On the blood agar plate, large gray, smooth, flat, mucoid, β-hemolytic
colonies were found. Although bacteria growing on solid media should not be
actively smelled, the organism emitted a grape or tortilla smell from the
plate. The organism was identified as Pseudomonas
aeruginosa by MALDI-TOF mass spectrometry. The isolate was plated onto Mueller
Hinton agar for Kirby-Bauer disc diffusion antibiotic susceptibility testing (Image 1). A fluorescent green lawn of bacteria
grew up to the edge of all discs, indicating high-level resistance to all
antibiotics tested (Table 1). Modified
carbapenem inactivation method (mCIM) testing was positive and Cepheid
GeneXpert CarbaR PCR testing revealed that this P. aeruginosa isolate carried the New Delhi metallo-β-lactamase-1
The issue of super bugs is on the rise, with the fear of
antibiotic resistance disseminating through more bacterial populations and
species. Carbapenems are drugs that are very powerful broad-spectrum
antibiotics, usually reserved as a last resort treatment for serious and
resistant infections.1 β-lactamases are divided into four Ambler
classes: A, B, C, and D. Class B differs from the others because it utilizes
zinc as a metal cofactor for its catalytic activity. The others use a serine
residue for their catalytic activity.2
NDM-1 is a class B β-lactamase. It was named after New Delhi, India when a Swedish resident presented with an extremely resistant infection after a trip to India in 2008. NDM-1 bacteria can now be found with high prevalence in India and China, and increasingly in other countries such as the UK and US.3,4 While the origination of the gene may not have been India, many of these infections are from people who have traveled to India or other Asian continents.5 Concerns about overprescribing and misuse of antibiotics in India are rising, where India is one of the biggest consumers of antibiotics in the world. One study even found striking evidence of this misuse, demonstrating that 2 out of 3 adults under 20 presented antibiotic resistance isolates to fluoroquinolones and/or cephalosporins.6,7,8
The gene for NDM-1 is blaNDM-1 and has been found on both plasmid and chromosomal components of different bacteria. Due to its presence on plasmids, the gene can easily spread through bacterial populations and other bacterial species – as has already been documented in Enterobacteriaceae and A. baumannii.3 The β-lactamase that it codes for is a lipoprotein that is anchored in the outer membrane of the gram negative bacteria. Other metalo-β-lactamases (MBLs) are periplasmic proteins, which are more affected by changes in essential metal cofactors in their enzymatic function. Thus far, it has been found that there are 16 discovered variants of NDM. Some variants being more fit than NDM-1. It is hypothesized that these variants are being selected for in the clinical setting, with the protein being more stable and demonstrating higher affinities for zinc during time of metal-chelating (a process the immune system adapts to combat infections).9 Unfortunately, NDM-1 and its variants are resistant to almost all antibiotics. Usually the only option is colistin and tigecycline.3
The disturbing issue, and the big picture, is the capability
of MDR organisms and their genes of disseminating. As previously mentioned, NDM-1
is capable of spreading to other species and within its population. Yet, a
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-Ben Dahlstrom is a recent graduate of the NorthShore University HealthSystem MLS program. He currently works as a molecular technologist for Northwestern University in their transplant lab, performing HLA typing on bone marrow and solid organ transplants. He graduated with a bachelors in Biology at the University of Illinois at Chicago (UIC) and concurrently from the UIC Honors College. He discovered his passion for the lab through his experience in healthcare. His interests include microbiology, molecular, immunology, and blood bank.
-Erin McElvania, PhD, D(ABMM), is the Director of Clinical Microbiology NorthShore University Health System in Evanston, Illinois. Follow Dr. McElvania on twitter @E-McElvania.