Microbiology Case Study: An 80 Year Old Man with a Violaceous Leg Lesion

An 80 year old male with a PMH of myelodysplasia with progression to AML and neutropenic fever presented with severe leg pain and violaceous leg lesion spanning a large portion of the left medial thigh and knee. There was no reported trauma. A radiograph demonstrated significant gas/air tracking in the tissues of the left medial thigh. He was given vanc/zosyn/clinda and subsequently transferred to UVMMC for further evaluation. He underwent debridement in the OR and fluid was sent for culture. Primary Gram stain showed no neutrophils and few gram positive bacilli. The blood agar plate and leg lesion are shown below.

Image 1. Growth on blood ager plate (BAP).
Image 2. Patient’s leg lesion.

This organism was identified on MALDI-MS as Clostridium septicum, consistent with the spreading colonies with irregular margins on blood agar. Box-car GPB morphology was present on gram stain, and although subterminal spores can be an additional clue to the identify C. septicum, they were not seen in this particular case.

Important diagnostic features of Clostridium septicum in the microbiology lab include:

  • GPB with rare subterminal spores (Image 3)
  • Gray/white colonies with irregular margins, translucent, β-hemolytic
  • Can show swarming growth pattern in < 24 hours on Schaedler plate (Image 4)
    • This swarming phenomenon is due to the ability to differentiate into giant hyperflagellated swarm cells, which can participate in migrations across surfaces
    • Major changes in virulence characteristics during swarming are reported
  • Lecithinase negative
  • Lipase negative
  • Gelatinase positive
  • Maltose positive
  • Indole negative
  • Urease negative
Image 3. Subterminal spores seen on Gram stain.
Image 4a. Swarming.
Image 4b. Swarming.

C. septicum is classically associated with GI malignancies and perforations when isolated in blood cultures. While less common than C. perfringens, Clostridium septicum can also cause gas gangrene (as in this case) along with C. novyi, C. histolyticum, C. sporogenes, and C. bifermentans. Importantly, in cases of nontraumatic gas gangrene, C. perfringens is the most common cause and classically presents as a primary perineum or extremity infection following bacterial translocation from the gastrointestinal tract. Patients with immune suppression, specifically neutropenia, are at increased risk of spontaneous gas gangrene due to C. septicum and have a high mortality rate.

To remember the colony morphology of the different Clostridial spp, you can think:

  • While C. Septicum Swarms, C. Perfringens Perforates (aka makes a double zone in the agar).

Edited to add: C. septicum is the most common cause of nontraumatic gas gangrene.

References

  1. McPherson, R, and M Pincus. (2011). Henry’s Clinical Diagnosis and Management By Laboratory Methods (22nd Edition, pp. 1155-1184). Philadelphia, PA: Elsevier Saunders.
  2. Murray PR et al: Medical Microbiology. 8th ed. Philadelphia: Elsevier, 2016
  3. Macha, Kosmas & Giede-Jeppe, Antje & Lücking, Hannes & Coras, Roland & Huttner, Hagen & Held, Jürgen. (2016). Ischaemic stroke and Clostridium septicum sepsis and meningitis in a patient with occult colon carcinoma – a case report and review of the literature. BMC Neurology. 16. 10.1186/s12883-016-0755-4.
  4. Stevens DL, Aldape MJ, Bryant AE. Life-threatening clostridial infections. Anaerobe. 2012;18(2):254–259.
  5. Macfarlane S, Hopkins MJ, Macfarlane GT. Toxin synthesis and mucin breakdown are related to swarming phenomenon in Clostridium septicum. Infect Immun. 2001;69(2):1120-1126. doi:10.1128/IAI.69.2.1120-1126.2001

-Nicole Mendelson, MD is a 3rd year Anatomic and Clinical Pathology Resident at the University of Vermont Medical Center.

-Christi Wojewoda, MD, is the Director of Clinical Microbiology at the University of Vermont Medical Center and an Associate Professor at the University of Vermont.

Microbiology Case Study: A Fishy Situation

Case History

The microbiology laboratory received a tissue specimen from a male patient in his 60s. The tissue was biopsied from the patient’s hand during surgery at an outside hospital, but no further clinical information was available. No organisms were observed on the Gram stain, fungal smear, or fluorochrome stain and no white blood cells were observed on the Gram stain. No organisms were recovered from the aerobic or anaerobic bacterial culture or fungal culture.

After 20 days of acid-fast bacilli (AFB) culture, yellow colonies grew on the Lowenstein Jensen (LJ) media and the 7H10 media (Image 1) and acid-fast bacilli were noted on the Kinyoun stain prepared from the colonies (Image 2).

Image 1. Yellow colonies on the 7H10 media.
Image 2. Kinyoun stain of the colonies demonstrating acid-fast bacilli. This is characteristic of Mycobacteria spp. Species-level identification is not possible based on morphology alone.

The ordering physician was contacted regarding the positive Kinyoun stain. Upon hearing that acid-fast bacilli grew in culture, the physician shared that he has a high suspicion for Mycobacterium marinum as this patient developed a wound infection after he cut his hand with a fish bone while cooking. MALDI-TOF identified this organism as Mycobacterium marinum, confirming the astute physician’s hypothesis. 

Mycobacterium marinum

Mycobacterium marinum is a slow growing non-tuberculous mycobacterium (NTM) that causes skin and soft tissue infections. M. marinum can be found in both fresh and saltwater environments and is commonly associated with contact with fish, fish tanks, marine shells, and non-chlorinated swimming pools, earning the names “swimming pool granuloma” and “fish tank granuloma.” Infections are normally localized to the skin and occur following trauma, with the limbs and extremities most often infected. Nodules or ulcers around the site of inoculation are most common—these are typically single nodules or ulcers but may spread along the lymphatic vessels to regional lymph nodes, similar to sporotrichosis. Rare manifestations of M. marinum include osteomyelitis and disseminated disease, with non-cutaneous manifestations occurring predominately in immunocompromised populations. M. marinum is a slowly progressing disease and the patient may not present to their provider until months after the initial trauma, often complicating the link to water or fish exposures. M. marinum, while it can be transmitted from fish to human, is not transmitted person-to-person and thus does not pose an infection control risk.

AFB cultures are typically incubated at 37 degrees C. However, M. marinum grows optimally at 30C with scant or no growth at 37degrees C. Thus, when skin and soft tissue samples are received for AFB culture, specimens should be held at both 37 degrees C and 30 degrees C to support growth of most NTM and to facilitate the growth of M. marinum, respectively. Recovery of M. marinum in culture from primary specimen takes several weeks to grow, but subculture may take less than 7 days.

M. marinum can be identified by phenotypic characterization, molecular identification, or mass spectrometry. M. marinum is a photochromogen, meaning that colonies possess a yellow pigment when grown in light and no pigment when grown in the dark. This is characteristic of group I of Runyon’s classification. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF), which has been used for years in most clinical microbiology laboratories for the identification of bacteria and yeast, can be used to identify Mycobacteria to the complex or species level. While the processing of Mycobacteria for MALDI-TOF is more laborious than for bacterial identification, the use of MALDI-TOF for identification of Mycobacteria is increasing in use. Whole genome sequencing can be performed on pure isolates for molecular identification, although this is more expensive and less common than MALDI-TOF or phenotypic identification.

A thorough history identifying risk factors for M. marinum should be conducted by the physician. Given the length of time for growth, clinical suspicion due to water or fish exposures can guide treatment before the organism grows in culture.  In addition to providing a diagnosis and guiding clinical care, a history of M. marinum infection is also critical to note for latent tuberculosis screening as M. marinum can cross react with tuberculin skin testing and interferon gamma release assays.

References

  1. Aubry A, Mougari F, Reibel F, Cambau E. Mycobacterium marinum. Microbiol Spectr. 2017 Apr;5(2). doi: 10.1128/microbiolspec.TNMI7-0038-2016. PMID: 28387180.
  2. Wu TS, Chiu CH, Yang CH, Leu HS, Huang CT, Chen YC, Wu TL, Chang PY, Su LH, Kuo AJ, Chia JH, Lu CC, Lai HC. Fish tank granuloma caused by Mycobacterium marinum. PLoS One. 2012;7(7):e41296. doi: 10.1371/journal.pone.0041296. Epub 2012 Jul 20. PMID: 22911774; PMCID: PMC3401166.
  3. Franco-Paredes C, Marcos LA, Henao-Martínez AF, Rodríguez-Morales AJ, Villamil-Gómez WE, Gotuzzo E, Bonifaz A. Cutaneous Mycobacterial Infections. Clin Microbiol Rev. 2018 Nov 14;32(1):e00069-18. doi: 10.1128/CMR.00069-18. PMID: 30429139; PMCID: PMC6302357.

Paige M.K. Larkin, PhD, D(ABMM), M(ASCP)CM is the Director of Molecular Microbiology and Associate Director of Clinical Microbiology at NorthShore University HealthSystem in Evanston, IL. Her interests include mycology, mycobacteriology, point-of-care testing, and molecular diagnostics, especially next generation sequencing.

Microbiology Case Study: A 59 Year Old Male with Acute Prostatitis

Clinical history

A 59 year old male with a past medical history of benign prostatic hypertrophy who presented to his primary care physician with complaints of dysuria, urgency, nocturia, and a weak stream. He was referred to a urologist who diagnosed him with acute prostatitis. The patient was given Flomax, a medication that relaxes the muscles in the prostate and bladder, and sulfamethoxazole-trimethoprim, an antibiotic for his possible bladder infection. The patient continued to have urinary symptoms despite antibiotics and multiple urinary cultures that were negative for growth of bacteria. Eventually the patient’s symptoms worsened and he presented to the emergency department with symptoms of fever (102.8ºF), bladder spasms, drenching night sweats, and painful urinary retention. His lab results showed a mild leukocytosis (15,500 cells /mm3) and increased leukocyte esterase, leukocytes, and erythrocytes in his urine. He was admitted and a pelvic computed tomography scan showed multiple prostatic abscesses. The infectious disease team ordered a urine fungal culture. The fungal stain showed broad-budding yeast forms (Image 1).

Image 1. Calcofluor white fungal stain highlighting brad-based budding yeast (100x oil immersion).

Laboratory identification

A cytospin Gram stain was made of the urine specimen which showed rare large yeast forms, numerous red blood cells and neutrophils (Image 2). These yeast forms are consistent with Blastomyces dermatitidis which are 10-15 µm in diameter and have thick contoured cell walls. The fungal culture grew a dirty white leathery mold on inhibitory mold agar after ten days. The lactophenol cotton blue adhesive tape preparation highlighted short to long conidiophores with large pear-shaped conidia at the tips of delicate conidiophores and septated hyphae. A positive urine antigen test supports the identification of the organism as Blastomyces dermatitidis.

Image 2. Large yeast with thick refractile walls seen on Gram stain. Flattened areas suggest recent separation.

Discussion

Blastomyces dermatitidis is a dimorphic fungus commonly found in the eastern half of the United States and Canada, specifically the Mississippi and Ohio River valleys, and Great Lakes Region. It typically grows as a mold in damp soil and decomposing vegetation; outdoor activities that disrupt the soil can increase the risk of infection. Infection occurs when the reproductive spores known as conidia are inhaled into the alveoli of the lungs. There the conidia transform into yeast and multiply causing the disease blastomycosis. Approximately 50% of those infected with Blastomyces are asymptomatic and clear the infection without trouble. For the other 50%, symptoms depend on the course of infection with a range of flu-like illness over a few days to chronic or severe illness that can last for months. Symptoms include fever, chills, headache, joint and muscle pains, shortness of breath, cough, night sweats, weight loss, and pleuritic chest pain. Twenty to forty percent of symptomatic patients will have disseminated disease. The common extra-pulmonary sites include skin, bone, urogenital, and the central nervous system, however, it has been reported in all organ systems.

In our case, the patient presented with prostatic blastomycosis which was quickly identified by calcofluor white fungal stain and urine antigen test. The patient was placed on itraconazole and a transurethral prostatic resection was performed. Histopathologic analysis showed necrotizing granulomas with fungal elements that are consistent with Blastomyces dermatitidis (Image 3). After a few days of treatment, the patient was discharged and is being followed on an outpatient basis.

Image 3. PAS stained tissue showing three budding yeast forms in a granuloma with extensive neutrophilic reaction.

– Joshua Wodskow, DO is a 1st year clinical and anatomic pathology resident at University of Chicago (NorthShore). Academically, Joshua has a particular interest in hematopathology and informatics. In his spare time, Joshua enjoys board games with his family and listening to podcasts.

-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. 

The More Things Change: 3 Ways to Determine Lab Safety Culture

On which side of the aisle do you stand regarding the subject of change? Things change, or things never change? The only constant is change, or it’s always the same old thing? When it comes to the laboratory safety culture, there are some generally-accepted thoughts; change is difficult, change is slow, and change takes persistence and patience.

I’ve heard other things too- people hate change, or people like change as long as they get to be in charge of it. I do believe most of us like change. After all, we change our clothes, we re-arrange our furniture, we remodel a room in our home. It can be exciting, but the tables seem to turn if it’s a change that is forced upon us or that was not our decision (Think about all of the changes the pandemic forced upon us last year!). Changing your lab safety culture for the better can be difficult, but it can be done. First, however, you need to know the current culture and goings-on in your lab in order to be able to make a difference.

There are specific ways to determine the safety culture in your lab. An experienced safety professional can do it fairly quickly. For others, especially those who serve in multiple capacities (you know who you are- you’re in charge of lab safety but you’re also the lab manager, or the quality coordinator, or the POCT coordinator) – for you assessing the culture can be difficult, even with years of experience- because you have so many other things on your plate. That can hinder your ability to make quick assessments, but it will not hinder you completely from being able to make a true safety assessment.

To make an assessment you need to use three specific tools that you likely have at your disposal. These tools may come in a variety of forms.

Those who have followed my work for some time know about the tool “Safety Eyes.” This is a safety assessment tool I believe to be a “superpower” that we all have and need to develop. It is so powerful, in fact, that a developed user can make a fairly good and accurate safety assessment with a quick glance into the department. Performing a lab safety audit is also a very valuable tool that can give you much information about the department’s culture. Perform a complete audit at least annually, and follow-up on the results. Otherwise, you have wasted your time and resources.

A second important safety culture gauge is the use of a written or electronic safety culture assessment. You may be able to tell what’s going on visually and physically by the evidence of your eyes and safety audits, but this tool is a way to actually get into the heads of your staff. What do they think of the culture? What is their opinion of it? What do they think needs improvement, and how would they suggest making those changes? A safety culture assessment can be given to everyone, or it can be used for specific lab groups. Survey the lab staff, survey those responsible for safety, or survey lab leadership. You should perform a lab safety culture assessment at least annually, but it can be done more often as needed.

Lastly, you can use laboratory data that you already collect to see the current state of safety in the department. Analyzing the data you collect about the injuries, accidents and exposures in your laboratory can be very eye-opening, and if you share the data as safety education, you may be able to lower the number of these types of incidents. Look at the chemical and biological spills in the lab. Analyze how they happened and how to prevent a re-occurrence. If you’re the quality coordinator for your lab or system, you know about root cause and common cause analyses. The incidents that occur in the lab that generate a root cause investigation may not always be about lab safety, but it’s possible that investigations show safety is a key factor, and those results should be reviewed with the safety person in the lab.

There is much fact-gathering in the laboratory setting, even regarding the topic of safety. However, all of that data becomes worthless if there is no action taken with it. Audits, injury data, spill information – it can be very valuable information and it can all be used as tools to help you truly change your lab safety culture. If you use them properly, you can make a change, you can make a difference, and you might just end up on the correct side of the change aisle!

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.

Methemoglobinemia

The primary role of hemoglobin in blood circulation is to deliver oxygen from lungs to tissues. Hemoglobin molecules comprise four polypeptide chains, e.g. two α and two β chains in hemoglobin A, with a heme group attached to each chain. Each heme group contains one iron atom, which can bind one oxygen molecule. Hemoglobin carrying oxygen molecule, known as oxyhemoglobin, gives out oxygen to tissue cells, and becomes deoxyhemoglobin, which can then load oxygen again. It is critical for the iron atom to remain in reduced state as ferrous (Fe2+) to bind to oxygen. Under oxidative stress, one or more iron atoms are oxidized to ferric (Fe3+) to form a brown color pigment, known as methemoglobin. Methemoglobin is unable to bind oxygen, and elevated level of methemoglobin or methemoglobinemia, can lead to cyanosis and be life-threatening.

A small amount of Fe2+ oxidizes to Fe3+ everyday but at the same time, methemoglobin converts back to hemoglobin through reducing activity of cytochrome b5-reductase. This maintains blood methemoglobin below 1% in normal circumstance. Methemoglobinemia can occur as inherited, mainly due to genetic defects of cytochrome b5-reductase, or as acquired, due to insufficient cytochrome b5-reductase activity under induced oxidative stress. Inherited methemoglobinemia is rare and patient may present mildly cyanotic and asymptomatic. Acquired methemoglobinemia can present acutely, more severe, and is most commonly encountered as a result of exposure to drugs and oxidant chemicals, such as local anesthetics, phenacetin, dapsone, and nitrites. FDA has released multiple warnings on the use of benzocaine-containing products, for its risk of causing serious, life-threatening methemoglobinemia. Benzocaine was found to be the causative agent of local anesthetic-related methemoglobinemia in two-thirds of cases.  

Methemoglobin can be detected and quantified in clinical laboratories with co-oximetry, which is capable of measuring absorbance at multiple wavelengths. The dual-wavelength pulse oximetry only measures oxyhemoglobin and deoxyhemoglobin and is unreliable in the setting of methemoglobinemia. The oxygen saturation calculated from partial pressure of oxygen is also unreliable, because it assumes a normal oxygen dissociation curve.

A case of an 88 year old male who underwent neurosurgery was found to have hypoxemic respiratory failure and subsequently developed acute pulmonary embolism. A blood sample was delivered to the laboratory for blood gas analysis and was soon noticed by a medical student that the blood has a dark brown color. The abnormal observation was discussed with the clinical team and a methemoglobin test was added on the specimen. Result of methemoglobin was as high as 48.6%, while oxygen saturation was falsely normal. Immediate treatment of methylene blue was initiated, and the treatment worked effectively and rapidly. A few hours after treatment, methemoglobin level was reduced to 3.3%. Upon reviewing patient’s history, it was noted that patient was given lidocaine for 3 days post-surgery, which may be the cause of methemoglobinemia. It is important to note that methemoglobinemia is a serious condition and can be fatal. Clinical diagnosis based on symptoms and history, as well as laboratory confirmation, are critical for timely management of methemoglobinemia.

Xin-small

-Xin Yi, PhD, DABCC, FACB, is a board-certified clinical chemist, currently serving as the Co-director of Clinical Chemistry at Houston Methodist Hospital in Houston, TX and an Assistant Professor of Clinical Pathology and Laboratory Medicine at Weill Cornell Medical College.

Microbiology Case Study: A 30 Year Old with Worsening Right Middle Finger Pain

Case History

A thirty year old male on dialysis with past medical history of nephrotic syndrome and end-stage renal disease presented to the emergency department due to complaints of severe abdominal pain. Culture of paracentesis fluid confirmed a diagnosis of bacterial peritonitis, and he was admitted for intra-peritoneal antibiotic therapy. During his admission however, he also complained of progressive worsening right middle finger pain and swelling after smashing his finger in a door one month prior. Upon exam the finger appeared visibly swollen with slight discoloration, but exhibited full range of motion (Image 1A). Imaging revealed osteomyelitis of the intermediate and distal phalanx, including involvement of the distal interphalangeal joint (Image 1B). Additionally, a small abscess was detected (Image 1B, inset) requiring incision and drainage (I&D). Following the I&D, the patient was discharged home on broad spectrum antimicrobial therapy pending results of intra-operative cultures. The patient was readmitted the following week for severe electrolyte imbalance due to a missed dialysis session. His right middle finger continued to cause him significant pain, and the I&D site appeared poorly healing with excess fluid drainage (Image 1C).

Image 1. A: Right distal right middle finger swelling at admission. B: MRI with IV contrast of the right hand revealed osteomyelitis with small abscess formation (inset). C: Right middle figure I&D site at readmission.

Laboratory Identification

Bacterial, fungal and mycobacterial cultures of purulent material from the I&D were obtained. Following four days of incubation, creamy white yeast-like colonies appeared on blood and chocolate agar plates at 35°C (Images 2A, B). Fungal medias grew colonies which were initially white (Image 2C), but became more wrinkled with increased central dark coloration and white periphery (Image 2D) within two weeks at 30°C. Cellophane tape preparations with lactophenol cotton blue were performed for microscopic evaluation of the mature colonies from potato dextrose agar. Narrow, septate hyphae with slender, tapering conidiophores were observed (Image 3A). The conidiophores had many small, tear-shaped hyaline conidia forming “daisy-like” clusters (Image 3B). Based upon these morphologic characteristics, the organism was identified as member of the Sporothrix schenckii complex.

Image 2. Culture of purulent material obtained from right middle finger I&D. A,B: Creamy white yeast-like colonies on blood and chocolate agar plates incubated at 35°C. Small white colonies (C) matured into moist, wrinkled colonies with central dark coloration (D) on fungal medias after 2 weeks’ incubation at 28-30°C.
Image 3. Lactophenol cotton blue (LCB) prep of fungal growth from plate in Figure 2D. Thin, septate hyphae were observed with tapered conidiophores and characteristic “daisy-like” clusters of conidia.

Discussion

Sporotrichosis (also known as rose gardener’s disease) is caused by dimorphic molds belonging to the Sporothrix schenckii complex. These fungi inhabit soil, plant matter and decaying vegetation, thus explaining their traditional association with gardening. As thermally dimorphic fungi, members of the Sporothrix schneckii complex exhibit both yeast and filamentous mold forms. The yeast colonies are smooth with cream or tan coloration when grown close to body temperature (35℃). Microscopically, the yeasts appear as round, oval and fusiform budding cells3,4 best visualized with GMS or PAS stains due to their relative infrequency when observed in tissue. These are commonly referred to as “cigar bodies”, and are typically seen on histopathology, sometimes with accompanying pyogranulomatous inflammation or suppurative granulomas.2 By contrast, the mold colonies begin small, white to pale-orange and become moist, wrinkled, leathery, or velvety and often darken to a salt-and-pepper brown-black as the mold ages. Microscopically, narrow, septate hyphae with slender, tapering conidiophores can be visualized. The conidiophore apex is often slightly swollen and bears many small, tear-shaped or almost round hyaline conidia (2-3 X 2-6 µm) on delicate hair-like denticles, forming the characteristic “rosette” or “daisy-like” clusters in young cultures.1,3,4 This also illustrates the etymology of the organism: from latin, spor (spore) + thrix (hair).5

The most common presentation of sporotrichosis is a lymphocutaneous form originating from a puncture or trauma that inoculates contaminated material into the wound. A pustule forms in subcutaneous tissue followed by ulceration and development of secondary lesions via lymphatic spread in a distal to proximal fashion.2 This form often occurs in immunocompetent individuals. More uncommon forms include osteoarticular, pulmonary, and disseminated infections, usually associated with immunocompromised hosts and alcoholics. In our case of osteoarticular sporotrichosis, the patient suffered from nephrotic syndrome which is often associated with immunodeficiency. The key inciting event to the development of his infection was likely the traumatic injury to his finger which was followed by wound inoculation of soil/material containing the organism. Following his diagnosis, the patient revealed that he was an avid gardener.

In conclusion, the patient was started on oral itraconazole initially for medical management. However, due to continued pain after a few weeks of therapy, the patient opted for amputation of the involved portion of the finger. Following successful amputation, the patient is to remain on itraconazole for one year due to concern for possible surgical margin involvement. He has healed well to date, with no continued pain in the remaining portion of the finger.

References

  1. Love GL, Ribes JA. 2018. Color Atlas of Mycology, An Illustrated Field Guide Based on Proficiency Testing. College of American Pathologists (CAP), p. 214-218.
  2. Pritt BS. 2018. Atlas of Fundamental Infectious Diseases Histopathology. College of American Pathologists (CAP), p. 120-122.
  3. Walsh TJ, Hayden RT, Larone DH. 2018. Larone’s Medically Important Fungi, A Guide to Identification. 6th Ed. ASM Press, p. 53, 178-180.
  4. St-Germain G, Summerbell R. 2011. Identifying Fungi: A Clinical Laboratory Handbook, 2nd Edition, Star Publishing Company Inc., pg. 238-239.
  5. Sellera, FP and Larsson, CE. 2019. Sporothrix schneckii. Etymologica. Emerg. Infect. Dis. 25(9):1631.

John Markantonis, DO is the current Medical Microbiology fellow at UT Southwestern and will be completing his Clinical Pathology residency in 2022. He is also interested in Transfusion Medicine and parasitic diseases.

Samira Peyrovi, M(ASCP)CM is a medical technologist at UT Southwestern Medical Center. She graduated with a degree in biology from Texas Women’s University and has worked in the microbiology section at Clements University Hospital for the past 5 years.

-Andrew Clark, PhD, D(ABMM) is an Assistant Professor at UT Southwestern Medical Center in the Department of Pathology, and Associate Director of the Clements University Hospital microbiology laboratory. He completed a CPEP-accredited postdoctoral fellowship in Medical and Public Health Microbiology at National Institutes of Health, and is interested in antimicrobial susceptibility and anaerobe pathophysiology.

Microbiology Case Study: A 59 Year Old with History of Rheumatoid Arthritis

A 59 year old male with a history of rheumatoid arthritis, hepatitis C, non-small cell lung carcinoma presents to his rheumatologist. His joint pain has responded well to adalimumab and methotrexate, but over the past month his left elbow has become increasingly painful, despite multiple corticosteroid injections there. He does not report any fevers or chills. On physical exam, his left elbow is warm and swollen. Synovial fluid is aspirated and sent for gram stain and culture.

Image 1. Initial Gram stain findings.
Image 2. Growth on potato flake agar.

The yeast was identified as Candida parapsilosis, a common environmental species of Candida that is becoming increasingly prevalent as a cause of invasive candidal disease. It is easily transmitted by contact and is a source of nosocomial infections. It has the ability to form a biofilm and, thus, has a predilection for indwelling catheters and prosthetic devices. Highest-risk groups include immunocompromised patients, surgical patients, and very low-birth weight neonates.

The microbiology findings exemplify how fungi can be broadly categorized based on how they grow (as a yeast or a mold) in the host and in culture (a cooler environment). In this particular case, the initial gram stain (figure 1), representative of the phenotype in the host, demonstrates neutrophils with intracellular organisms with visible cell walls, suggestive of an active yeast infection with ongoing phagocytosis. The potato flake agar (figure 2) is also growing a yeast. Thus, the pathogen is classified as a yeast. In contrast, molds are characterized by the development of hyphae, which give them their classic “fluffy” appearance in culture (absent in this case). A clinically important subset of this group, the dimorphic fungi, are defined by a yeast phenotype in the host and a mold phenotype in culture.

References

  1. McGinnis, M, and S Tyring. (1996). Medical Microbiology (4th Edition). Galveston, TX: University of Texas Medical Branch at Galveston.
  2. McPherson, R, and M Pincus. (2011). Henry’s Clinical Diagnosis and Management By Laboratory Methods (22nd Edition, pp. 1155-1184). Philadelphia, PA: Elsevier Saunders.
  3. Trofa, D, A Gacser, and J Nosanchuck. “Candida parapsilosis, an Emerging Fungal Pathogen.” Clin Microbiol Rev. 2008 Oct; 21(4): 606-625.

-Frederick Eyerer, MD is a 3rd year anatomic and clinical pathology resident at the University of Vermont Medical Center.

-Christi Wojewoda, MD, is the Director of Clinical Microbiology at the University of Vermont Medical Center and an Associate Professor at the University of Vermont.

Microbiology Case Study: An 83 Year Old Man with History of Dementia

An 83 year old man presents to an emergency department after an unwitnessed fall and being found down for an undetermined amount of time.  His past medical history includes dementia and type II diabetes mellitus.  A tick is found in his left groin.  Workup reveals mild rhabdomyolysis, mild transaminitis, thrombocytopenia, and multiple infiltrates on chest x-ray, concerning for aspiration pneumonia.  His hospital course is complicated by fever, hypotension, and atrial fibrillation with rapid ventricular response.  Representative images from his peripheral blood smear are shown below.

PCR confirmed the diagnosis of Anaplasma phagocytophilum.  The patient recovered after a 10-day course of doxycycline.

Differentiating Tick-Borne Intracellular Microorganisms

The clinical findings of recent tick exposure, thrombocytopenia, transaminitis, and acute illness are consistent with acute infection with either Ehrlichia or anaplasma.  The images depict morulae (microcolonies of bacteria) within the cytoplasm of neutrophils.  A. phagocytophilum, Ehrlichia chaffeensis, and Babesia microti can all be seen intracellularly on peripheral blood smears.  A. phagocytophilum preferentially infects neutrophils, while E. chaffeensis infects monocytes and B. microti infects erythrocytes.  Unlike A. phagocytophilum and E. chaffeensis, which both appear as intracellular morulae (clusters of bacteria), B. microti is a protozoa whose trophozoite forms are seen in red blood cells as delicate rings or grouped in tetrads (the characteristic “Maltese cross”).

The finding of morulae in granulocytes has a sensitivity of 20-80% for anaplasmosis within the first week of infection.  However, morulae within granulocytes are also found in infection with Ehrlichia ewingii (human granulocytotropic Ehrlichiosis, distinct from human monocytotropic Ehrlichiosis caused by E. chaffeensis), a less common relative of E. chaffeensis that is also transmitted by the Lone Star tick (Amblyomma americanum) and appears to preferentially infect immunocompromised hosts.  For E. chaffeensis, the sensitivity of finding morulae in monocytes is only 7-17% amongst immunocompetent hosts.

References

  1. Chapman, AS,  JS Bakken, SM Folk, et al.  “Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever, ehrlichioses, and anaplasmosis–United States: a practical guide for physicians and other health-care and public health professionals.” MMWR Recomm. Rep. 2006; 55(RR-4):1.
  2. McPherson, R, and M Pincus.  (2011).  Henry’s Clinical Diagnosis and Management By Laboratory Methods (22nd Edition, pp. 1073-1074, 1205).  Philadelphia, PA:  Elsevier Saunders.
  3. Paddock, CD, SM Folk, GM Shore, et al.  “Infections with Ehrlichia chaffeensis and Ehrlichia ewingii in persons coinfected with human immunodeficiency virus.” Clin Infect Dis. 2001; 33(9):1586-94.
  4. Schotthoefer, AM, JK Meece, LC Ivacic, et al.  “Comparison of a Real-Time PCR Method with Serology and Blood Smear Analysis for Diagnosis of Human Anaplasmosis: Importance of Infection Time Course for Optimal Test Utilization.” J Clin Microbiol. 2013 Jul; 51(7): 2147-2153.

-Frederick Eyerer, MD is a 3rd year anatomic and clinical pathology resident at the University of Vermont Medical Center.

-Christi Wojewoda, MD, is the Director of Clinical Microbiology at the University of Vermont Medical Center and an Associate Professor at the University of Vermont.

Critical Value

(No. Not that kind of critical value; your patient’s hemoglobin is absolutely fine…)

Hello again everyone! Back from a relevant and important case-study last month, I’d like to pivot to highlighting an important annual celebration that happens every May 6-12th around the world: International Nurses’ Day.

I know, I know. This is a blog for medical laboratory professionals, what gives? We get lab week, they get nurses’ week…separate but equal? In my opinion, not exactly the best modus operandi for collaborative medicine. In fact, nursing and laboratory medicine have both had a rich, connected, and parallel history for decades and the professional intersections of their efforts is something to be celebrated!

A lot of current published literature focuses on nursing in the pre-analytical realm of specimen collection and processing. That’s totally fine, and quite important to diagnostic testing, but if you go back a few decades with me it’s clear to see we’re both frontline medical professionals—and that’s without a global viral pandemic!

Image 1. I’m sorry but the label needs to be dated and initialed at bedside—KIDDING. That happens a lot I’m sure (I would know), but nurses and medical laboratory scientists (technologists) have been counterparts for decades. The present is no different. We are two parts of a strong interdisciplinary, collaborative effort to improve healthcare for our patients. After all, we’re always #StrongerTogether. (Source: Laboratory Medicine, June 1970)

In the very first issue of Laboratory Medicine¸ one of ASCP’s main journals, an article discussed the critical communication between nursing and the laboratory. The bottom line (from 1970)? Doctors and nurses might use “stat” too much, and medical technologists are very busy folks—has anything changed? In another piece in the same journal from 1984, the topic of MLS (then MT) recognition was examined. Almost 14 years apart, this article highlighted that the lab wished for recognition, and that doctors and nurses valued their MT’s experience and knowledge, despite their work behind the scenes. Fast forward to the present, professional societies like ASCLS have established national celebrations of our hard work with Medical Laboratory Professional’s Week in April. In May, the International Council of Nurses (and our American Association of Nursing) promotes Nurses’ Week. Our super-hero themed celebration of diagnostic excellence and commitment is matched by their theme of nursing the world back to health. The World Health Assembly designated 2020 as the year of the nurse for obvious reasons. None of us would be able to thrive, survive, or work in or out of healthcare without nurses. So for this year’s Nurses’ Week, Nurses’ Day, or even the Year of the Nurse, this pathology postgraduate-trainee is happy to celebrate our clinical friends and colleagues.

Image 2. Melizza, Nataliya, Donna, and Roksana are the nurses that manage Loyola’s robust apheresis clinic service. I don’t think it would run without them. They effectively demonstrate that nursing is critical across any specialty, and patient safety and outcomes are directly related to the care they receive.

Significant parts of pathology and laboratory medicine rely heavily on nurses. In transfusion medicine, you wouldn’t be able to have any significant apheresis clinic activity without the compassion and attention of nurses. Clinical Pathologists really lean on the knowledge, skill, talent, grace, compassion, and dedication of the nurses that care for patients receiving this highly specific and specialized treatment modality. Think about how other “interventional pathology” specialties like cytopathology or hematopathology would suffer without the commitment of nurses to keep our patients safe during a fine-needle aspiration, or bone marrow collection.

I write a lot about our work in pathology and laboratory medicine, from bench to bedside, but considering our nursing colleagues:

Nurses are kind.
Nurses are brilliant.
Nurses are skilled.
Nurses work in all kinds of roles, jobs, and settings.
Whether they work in an office, clinic, or hospital unit, care for you or a loved one, close the learning gaps for a medical student or resident, champion for better outcomes for one patients or thousands or people at once; our lives are all better for it. Their work never ends, and our need for them never will.

Image 3. Mini-brag: my wife (who has secretly appeared in a few ASCP-related media as she accompanies me to meetings—and even roundtables!) is a nurse and a fantastic one. An INF Top 40 Under Forty Nursing Leader, a former community-based health clinic non-profit chief of staff, an internationally renowned lecturer on emergency and disaster mitigation strategies, and a very important Chicago region disaster response manager who’s inches from finishing her DNP in Public Health so, like, what am I even doing…?

I obviously see the value and impact of nursing every day. Doesn’t hurt that I’m surrounded by great ones at work and at home.

Happy (belated) Nurses Week!

Thanks for reading, see you next time!

Constantine E. Kanakis MD, MSc, MLS(ASCP)CM is a first-year resident physician in the Pathology and Laboratory Medicine Department at Loyola University Medical Center in Chicago with interests in hematopathology, transfusion medicine, bioethics, public health, and graphic medicine. He is a certified CAP inspector, holds an ASCP LMU certificate, and xxx. He was named on the 2017 ASCP Forty Under 40 list, The Pathologist magazine’s 2020 Power List and serves on ASCP’s Commission for Continuing Professional Development, Social Media Committee, and Patient Champions Advisory Board. He was featured in several online forums during the peak of the COVID pandemic discussing laboratory-related testing considerations, delivered a TEDx talk called “Unrecognizable Medicine,” and sits on the Auxiliary Board of the American Red Cross in Illinois. Dr. Kanakis is active on social media; follow him at @CEKanakisMD.

Win, Lose, or Draw?

In the 1962 Japanese release of King Kong vs. Godzilla, it was pretty easy to determine who the winner of the epic battle was (it was Kong, if you’re keeping track). Almost 60 years later, the two famous giant behemoths met again on the big screen, this time in an American version. This second battle, while fun to watch, had a less-obvious outcome. Those who sided with either monster had moments to cheer during the movie, but in the end, (spoiler alert!) a secondary issue overshadowed the much-hyped monster match. It seemed obvious to me that the script writers tried their best to satisfy audiences on both sides of the aisle. In doing this, however, the movie lost a little bit of its punch. That can happen in lab safety as well. If the message isn’t strong or clear, safety issues will ensue.

The lab manager noticed an increase in employee injuries on the job. Someone cut their finger on a microtome blade. Two different specimen processors splashed serum into their eyes. A night shift tech kneeled onto the floor to pick up a box, and her knee landed on broken glass that hadn’t been swept up. It was clear people were not paying close attention while they were performing their duties. The manager held a meeting in the lab to raise safety awareness. He delivered his message, but staff noticed he was chewing gum and that he did not put on a lab coat even though he was in the lab for over 20 minutes. The message was not clear. He said he was for a safer lab, but he didn’t look to anyone like he meant it.

Jake was new to the histology lab and he was excited to make a good impression as he began his career. During his departmental orientation, the supervisor stressed the importance of chemical safety. Formaldehyde and xylene were in use in the department, and they were potentially dangerous. Jake got the message and was ready to show the department he could work there safely. After orientation was done, Jake came to work to begin cutting tissue. When he sat down at his station, he opened the drawer for supplies and saw a packet of oatmeal a spoon, and a coffee cup. The medical director came in to the lab to welcome Jake, and he noticed she was drinking tea. The message Jake received about safety was no longer clear. The supervisor spoke about safety, but it was clear no one enforced it.

When the message we send to staff about lab safety is mixed, we really can’t blame them when the culture is bad. The problem is that many leaders are not aware they are sending this confusing communication. If you’re not sure if you are one of those leaders, take a step back and look in the mirror. What kind of message do you send? Do you support safety? Do you do it with your words AND your actions? What sort of example do you set?

If you’re not in lab leadership, you still have a responsibility to represent safety with your lab practices as well. Everyone has an impact on the overall safety culture, not just leaders. What do you do to promote safety in your department?

Maybe you are an employee and it’s your leader who is sending mixed messages. First, make sure you’re choosing the side of safety in your work no matter what others are doing. Second, it may be time to “manage up” and ask leadership why certain unsafe practices occur. If the leader is part of the problem, it is acceptable to point that out, provided you do so with purpose, tact and professionalism.

Leading by example for safety is vitally important no matter your role in the department. Choose your side, stick to it in all circumstances, and over time you will be able to be declared the decisive winner. Those mixed safety messages usually lead to a draw, or worse, a loss for the team. 

Because I have been a Godzilla fan for decades, I thoroughly enjoyed this latest film entry. In truth, I was able to discern a clear winner of his fight with Kong despite the writer’s intentions, but that may be because I had support for my favorite going in. That might be your way to victory as well. Root for “Team Safety,” and your support will be noticed and followed for the win!

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.