Microbiology Case Study: A 22 Year Old Female with Wound Infection

 

Case History

22 year old female with a past medical history of scoliosis presents for routine follow-up after hospital discharge for post-op wound infection following a spinal fusion surgery. Patient had an anterior and posterior spinal fusion with allograft and hardware on 1/18/18. She had a laminectomy and irrigation for post-op epidural hematoma on 1/19/18. Subsequently, she developed a lumbar spine abscess and underwent irrigation and debridement of the abscess on 3/1/18. Two operative cultures of the left paraspinal musculature grew only tiny clear colonies on the anaerobic blood plates. Gram stain of these colonies did not show any organism. MALDI-ToF MS identified these colonies as Mycoplasma hominis which was confirmed at a reference laboratory by PCR. The patient was given daptomycin plus levofloxacin. Since discharge from the hospital, she had wound healing with intermittent discharge.

Lab Identification

Mycoplasma hominis requires a specific rich and complex agar medium for growth and grows tiny colonies on standard media such as Columbia agar. In a patient with urogenital disease, Mycoplasma hominis is diagnosed with a urogenital specimen culture and confirmed by PCR. In a patient with spinal hardware infection, Mycoplasma hominis is diagnosed by a culture of infected tissue with PCR confirmation.

Discussion

Mycoplasma is a bacteria that lacks a cell wall and contains the smallest bacterial genome totally sequenced. Due to its lack of cell wall, Mycoplasma cannot be visualized with a Gram stain, and it is innately resistant to b-lactams.1 Due to its small bacterial genome, 580 kpb, it cannot be detected by light microscopy and requires complex nutrients for growth1.

Mycoplasmas are frequently part of the oropharyngeal and genital tract flora among healthy subjects.1 There are more than 200 Mycoplasma species, of which 13 have been isolated from humans. Only 6 species, among which 5 are pathogens, live in the urogenital tract.2 As one of the Mycoplasma species detected in the genitourinary tract, M. hominis can be either a pathogen or part of the normal flora.1 Colonization with M. hominis is associated with younger age, lower socioeconomic status, multiple sexual partners, African American ethnicity, and hormonal status.1 Infection with M. hominis is more common among pregnant women.1

Mycoplasma hominis is associated with genital infections in females but not in males. Examples of infections include pelvic inflammatory disease and bacterial vaginosis.1 In addition, it is responsible for pregnancy-related infections such as chorioamnionitis and post-partum fever secondary to endometritis.1 Moreover, M. hominis is associated with infections of the newborns, meningitis among premature babies, and low birth weight among neonates.1 Lastly, M. hominis can lead to extragenital infections including spinal hardware infections, septic arthritis, retroperitoneal abscess, hematoma infection, and osteitis.1

Infections by Mycoplasma hominis are infrequent and difficult to confirm prior to the start of empiric therapy.2 Urogenital and systemic infections due to Mycoplasma hominis are treated with oral tetracycline.1 For organisms resistant to tetracycline, fluoroquinolones are recommended.1 For wound infections or abscesses, doxycycline, clindamycin, or fluoroquinolones are recommended for at least 2 weeks.1 Drainage and debridement may be necessary.1

References

  1. Pereyre S. et Mycoplasma hominis, M. genitalium and Ureaplasma spp.  Antimicrobe http://www.antimicrobe.org/m06.asp
  1. Baum S. Mycoplasma hominis and ureaplasma urealyticum infections. (2017, Dec. 7th).  Last retrieved on March 27, 2018 from https://www.uptodate.com/contents/mycoplasma-hominis-and-ureaplasma-urealyticum-infections

 

-Ting Chen, MD is a 1st year anatomic and clinical pathology resident at the University of Vermont Medical Center.

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-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 70 Year Old Female with Bronchiectasis

Case History 

A 70 year old female presents with bronchiectasis with acute exacerbation. She is a non-smoker, although claims to have been exposed to secondhand smoke, and she has chronic sinusitis. The patient recently traveled to Savannah, Georgia where she developed a productive cough. She was prescribed doxycycline and was then sent home. She returned to the pulmonary clinic for a follow up consultation after her cough worsened.

Laboratory Identification

hflu1
Image 1. Intracellular gram negative coccobacilli with polymorphonuclear cells found in the sputum smear (100x oil immersion).
hflu2
Image 2. The predominant organism found in this patient’s sputum culture is growing 4+ on chocolate agar, but not growing on blood and MacConkey agars.
hflu3
Image 3. Close up of chocolate agar showing 4+ growth of wet, translucent colonies.

The Gram stain and smear showed 4+ neutrophils, 4+ gram negative coccobacilli and little to no mixed respiratory flora. The following day, the culture grew 1+ respiratory flora on the blood plate, no growth on the MacConkey plate, and 4+ translucent colonies on the chocolate plate. 

Discussion 

The predominant organism was identified by the MALDI-TOF as Haemophilus influenzae. The Gram stain and culture findings are consistent with the MALDI-TOF identification. H. influenzae is an oxidase positive, gram negative coccobacilli known for its requirement of X (hemin) and V (NAD) factors found in chocolate agar. Because of its growth requirements, H. influenzae will not grow on MacConkey agar despite being a gram negative organism. It may be cultured on blood agar if the agar is inoculated with an organism such as Staphylococcus aureus, which can provide the V factor, while the X factor is provided by the agar itself. This phenomenon is known as satelliting. Identification of H. influenzae may also be done using a Haemophilus ID Quad plate. Each section of the plate contains varying factors and allows for Haemophilus identification to the species level based on the growth and hemolysis pattern.

H. influenzae is normal flora of mucous membranes and frequently colonizes the human oral cavity and upper respiratory tract. Commonly, H. influenzae causes pneumonia, as with our patient, bronchitis, and ear infections. However, it is also a known cause for bacterial meningitis, endocarditis, and osteomyelitis. Transmission of H. influenzae occurs through respiratory droplets so proper PPE precautions must be taken by clinicians when working with infected patients. It is important for laboratory professionals to work with the organism using proper PPE and BSL-2 practices and plating of respiratory specimens should occur in a biosafety cabinet.

Susceptibility testing is not routinely performed on isolates of H. influenzae. β-lactamase production can be determined by using nitrocefin, a chromogenic cephalosporin spot test. 

References

  1. Haemophilus influenzae Disease (Including Hib). (2018, February 13). Retrieved June 28, 2018, from https://www.cdc.gov/hi-disease/index.html
  2. (2012, March 15). Retrieved June 28, 2018, from https://www.cdc.gov/meningitis/lab-manual/chpt09-id-characterization-hi.html. Identification and Characterization of Haemophilus influenzae
  3. Manual of Clinical Microbiology, 11th edition

 

MS

-Madaine Saguinsin, MLS (ASCP), graduated from Purdue University with a BS in Medical Laboratory Sciences and is a medical technologist at NorthShore University Health System. Her interests are microbiology and parasitology.

-Erin McElvania, PhD, D(ABMM), is the Director of Clinical Microbiology NorthShore University Health System in Evanston, Illinois.

Microbiology Case Study: A 60 Year Old Female with Right Ear Pain

Case History

60 year old female presents to the emergency department with increased pain in her right ear and decreased hearing. She denies ear discharge. She endorses vertigo for 7 months that is precipitated by sudden changes in head position. On physical exam, the right ear canal is obscured by a foreign body. Ear swab is positive for growth on fungal culture.

Lab Identification

Image 1. Salt and pepper fungal colonies isolated from ear swab.

aspniger
Image 1. Salt and pepper fungal colonies isolated from ear swab.
aspniger2
Image 2. Septate hyphae with unbranched condidiophore connected to a swollen vesicle covered in phialides that produce chains of conidia.

The identification of Aspergillus niger is made based on macroscopic colony morphology and microscopic structures. On the potato flake agar, Aspergillus niger grows salt and pepper colonies. For microscopic examination, a slide is made by touching the colonies with a piece of clear tape, putting a drop of lactophenol analine blue on a glass slide, and placing the tape on the slide. Microscopically, Aspergillus niger appears as septate hyphae with long smooth unbranched conidiophores. Compared with other Aspergillus species, the phialides of niger cover the entire vesicle and form a “radiate” head, which splits into several loose columns.

Discussion

Aspergillus is a common mold that lives both indoors and outdoors. The Aspergillus genus is composed of 180 species, among which 34 are associated with human disease.1 A. fumigatus is the most common cause of aspergillosis syndromes. A. terreus is a species of particular concern due to its resistance to amphotericin. An invasive disease due to A. terreus has a poor prognosis.1

Healthy individuals inhale hundreds of conidia of Aspergillus per day without illness. However, people with a weakened immune system or lung disease are at higher risk of developing infections from inhaling the condidia. Presentations of aspergillosis range from allergy to fungal balls, to dissemination.1 Examples of aspergillosis include asthma, allergic bronchopulmonary aspergillosis, and allergic sinusitis.1

Invasive otitis externa due to Aspergillus is a rare, potentially life-threatening invasive fungal infection affecting immunocompromised patients.2 It spreads from the external auditory canal to adjacent anatomical structures such as soft tissues, cartilage, and bone.2 The condition can lead to osteomyelitis of the base of the skull with progressive cranial nerve palsies, irreversible hearing, and neurological impairment.2 The infection can be treated with antifungals.

References

  1. Barnes PD, Marr KA. Aspergillosis: spectrum of disease, diagnosis, and treatment. Infect Dis Clin North Am. 2006 Sep;20(3):545-61, vi.
  2. Parize, P. et al. Antifungal Therapy of Aspergillus Invasive Otitis Externa: Efficacy of Voriconazole and Review. Antimicrobial agents and chemotherapy. 2018 April; 62(4). http://aac.asm.org/content/53/3/1048.long

 

 

-Ting Chen, MD is a 1st year anatomic and clinical pathology resident at the University of Vermont Medical Center.

Wojewoda-small

-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 10 Year Old with Fever and Chills

Case History

A 10 year old female presented to the pediatric emergency department (ED) with a chief complaint of persistent fever and chills for the past 10 days. Her mother reported the fevers reached up to 103°F and temporarily would respond to ibuprofen.  She also noted a decrease in the patient’s appetite, tiredness and a bumpy rash on her truck and extremities. In the ED, she was clinically stable but her temperature reached a max of 104.7°F. On physical examination, shotty cervical lymphadenopathy was noted and there was no appreciable enlargement of the liver or spleen. Initial laboratory testing showed a white blood cell count of 10.6 TH/cm2 (normal range: 4.3-11.4 TH/cm2) and elevated acute phase proteins (ESR 45 mm/HR and CRP 2.6 mg/dL). Blood cultures were collected and the patient was started on ceftriaxone. Pediatric infectious disease was consulted and a thorough infectious work up was completed.

Laboratory Identification 

  • Rapid influenza antigen test: Negative
  • Rapid Group A Strep antigen test: Negative
  • Rapid Monospot: Negative
  • HIV antigen/antibody (4th generation) test: Negative
  • Legionella urinary antigen: Negative
  • Histoplasma urinary antigen: Negative
  • Antinuclear antibody: Negative
  • Rheumatoid factor: Negative
  • Urine culture: Negative
  • Blood cultures: Negative
  • Bartonella henselae IgM: ≥1:20 (normal <1:20)
  • Bartonella henselae IgG: ≥1:1024 (normal <1:128)

Infectious disease and rheumatologic work ups, as listed above, were negative with the exception of a positive IgM and IgG serologic testing for Bartonella henselae, with the results suggesting a recent infection based on the elevated titers. Upon further questioning, the family did have many outdoor cats and dogs; however, the child denied any recent bites or scratches.

Discussion 

Bartonella henselae is a facultative, Gram negative coccobacillary rod that is the causative agent of cat scratch disease and bacillary angiomatosis. The main reservoir for B. henselae is cats and the disease is spread from cat to cat via the cat flea. Feral cats, outdoor cats and young kittens, especially those living in hot, humid environments where fleas are plentiful, are more likely to be infected and spread the disease to humans via infective flea feces during a scratch or bite from the cat.

The incubation period for B. henselae ranges from 1-3 weeks and the majority of patients present with systemic symptoms including fever, chills, malaise, anorexia and headache. In addition, painful lymphadenopathy, on the side of the body where the scratch occurred (most common upper extremity), can be present in the epitrochlear, axillary and cervical regions. Less frequently, B. henselae causing bacillary angiomatosis can result in the proliferation of vessels in organs (liver and spleen). Though rare, encephalopathy and endocarditis due to B. henselae are the most severe manifestations of disease.

In the microbiology laboratory, the diagnosis of B. henselae is challenging due to the fact it is slow growing, highly hemin dependent and requires high humidity conditions for growth. The organism will grow on chocolate and heart infusion agars containing 5% fresh rabbit blood. Plates should be incubated at 35°C with 5% CO2 with high humidity for at least 4 weeks. Colonies are irregular and off-white in color and B. henselae is negative for both catalase & oxidase and asaccharolytic.

Due to the identification difficulties with culture, serologic testing is the main methodology for the diagnosis of B. henselae. Enzyme linked immunosorbent assays (ELISA) are relatively easy to perform and provides good results, although the provider should be aware of the sensitivity of the particular platform, the fact that cross reactivity with other Bartonella spp. can occur and seronegative infections can sometimes occur. Warthin-Starry silver stain on fixed tissue sections from lymph nodes and other organs can be helpful as well; however, it is relatively insensitive and not highly specific.   

 With regards to treatment, there are no agreed upon breakpoints for B. henselae published by CLSI or EUCAST. Microdilution or Etests can be used for testing and isolates have been susceptible to many antibiotics. In general, for cat scratch disease, it does not respond to antibiotic therapy and there is only a minimal benefit of antimicrobial agents. In the case of our patient, she was switched from ceftriaxone to a five day course of azithromycin with a gradual improvement of her fever curve. She was scheduled to follow up with pediatric infectious disease in 2-3 weeks.

 

Stempak

-Lisa Stempak, MD, is an Assistant Professor of Pathology at the University of Mississippi Medical Center in Jackson, MS. She is certified by the American Board of Pathology in Anatomic and Clinical Pathology as well as Medical Microbiology. She is the Director of Clinical Pathology as well as the Microbiology and Serology Laboratories.  Her interests include infectious disease histology, process and quality improvement and resident education.

Tissue is the Issue: Microorganism Identification (part 3)

In parts 1 and 2, we discussed pre-analytical and analytical issues that can be faced when culturing tissue specimens. Part 3, the final part of the Tissue is the issue series, will review analytical and post-analytical issues of tissue culture requests. 

The Issue

Let’s consider a case of “culture-negative” endocarditis (1), in which organism was detected during direct observation of the specimen (2); but as you would expect for suspected “culture-negative” endocarditis, the culture does not yield an organism. This can happen for a variety of reasons. Perhaps the culture request was for a routine aerobic culture, but the organism was a strict anaerobe and therefore could not grow. Maybe the patient was on antibiotics, so the organism observed was not viable. Or it is possible that the organism in question is fastidious and requires special media or growth conditions which were not met. Another frequent occurrence is that tissue is sent for pathology, but not for culture. This is more common when malignancy is expected, but the pathological findings suggest an infectious process. These scenarios may seem hopeless, but don’t despair; there is a non-culture alternative that can aid in identifying the causative agent. 

The Solution

Microbial (bacterial, fungal, and viral) DNA can be detected from fresh, frozen, or fixed tissue. Simply put, DNA is first extracted from the specimen, of which the microbial DNA of interest (bacterial, fungal, viral) is then amplified via PCR. Broad-range or pathogen-specific PCRs are commonly available from a variety of reference laboratories. If broad-range PCR is performed, then sequencing of the amplicon is required to determine the organism identification. Sequences are queried against a library of known microbial genomes to obtain a match.

Depending on the DNA of interest, different primer sets are utilized. For broad-range bacterial PCR, the 16S ribosomal RNA gene is typically used. Although mycobacteria are bacteria, they require additional gene targets for optimal detection and identification (16S rRNA, rpoB, and hsp65). For fungi, the 28S rRNA and the ITS (internal transcribed spacer; ITS1 and ITS2) genes are used.

The organism burden and specimen type can affect the probability of detecting an organism and obtaining its identification. The likelihood of a positive outcome is proportional to the organism burden. For example, if organism observed in the direct exam (i.e., Gram or acridine stain), then the organism can usually be detected and identified. However, if no organism is observed, then the chances of a positive result is unlikely. Therefore, our protocol is to only send specimens for microbial DNA sequencing on specimens in which organisms were observed in the direct exam. This is true for all specimen types (fresh, frozen, fixed).

It is important to note that fixed specimens may not yield as good results as a fresh or frozen specimen. This is because the process of fixation can degrade the microbial DNA (3). Additionally, because detection of microbial DNA is the basis for pathogen identification, susceptibility results are not going to be available. Treatment options will need to be based on known empiric therapies.

The Conclusion

Microbial DNA sequencing is a viable option for the identification of etiological agents of infection from a variety of sources, such as culture-negative infections. Other uses include slow-growing organisms and organisms that are unidentifiable by traditional methods (4). In my experience, this is a valuable tool that should be considered when culture does not yield a result and a result is necessary to drive clinical decisions. 

References

  1. Tissue is the Issue, Part 1
  2. Tissue is the Issue, Part 2
  3. Martinez, R.M. Genes in your tissue: probe identification and sequencing microbial targets from formalin-fixed, paraffin-embedded tissue. Clin. Microbiol. Newslett. 36: 139-147.

 

Martinez Headshot-small 2017

-Raquel Martinez, PhD, D(ABMM), was named an ASCP 40 Under Forty TOP FIVE honoree for 2017. She is one of two System Directors of Clinical and Molecular Microbiology at Geisinger Health System in Danville, Pennsylvania. Her research interests focus on infectious disease diagnostics, specifically rapid molecular technologies for the detection of bloodstream and respiratory virus infections, and antimicrobial resistance, with the overall goal to improve patient outcomes.

Microbiology Case Study: An 88 Year Old Male with Headache

Case History

An 88 year old male presents with fever, nausea, and headache. The patient reported a diffuse headache accompanied by malaise, fatigue, and nausea without vomiting. He denied confusion, irritability, or a personal and family history of headaches. According to the patient, he frequently attends cookout parties and enjoys fruits, salads, wine, and cheese. Temperature is 38.2 degrees Celsius, blood pressure is 96/65 mmHg, pulse is 102 beats/minute, and respiratory rate is 20 breaths per minute. Physical exam is negative for nuchal rigidity and Kernig sign. Funduscopic exam is negative for papilledema. CBC shows leukocyte count of 16,000/mm3. The patient’s blood culture is positive.

Laboratory Identification

listmono1
Image 1. Short gram positive bacilli identified on Gram stain of blood culture (100x oil immersion).
listmono2
Image 2. Aerobic growth of round and translucent colonies with a narrow zone of beta hemolysis subcultured from positive blood culture bottle to sheep blood agar plate.

The blood culture was positive for short, gram positive bacilli. Sheep blood agar plate grew round and translucent colonies which have a narrow zone of beta hemolysis as shown on our plate. The organism was catalase positive and motile at 25 degrees Celsius. It showed end over end tumbling motility in a wet prep and an umbrella pattern in semi-solid motility medium. It was identified by MALDI-ToF as Listeria monocytogenes.

Discussion

Listeria monocytogenes is a gram positive bacillus that is isolated from the environment and a variety of animals. It is associated with foodborne outbreaks from dairy and meat products. The most common foods associated with listeriosis outbreaks include unpasteurized raw milk, cold deli meat, hot dogs, raw sprouts, smoked seafood, and soft cheese.1

Listeria commonly infects pregnant women, immunocompromised individuals, and elderly 65 years or older.1 Among pregnant women, Listeria can lead to miscarriages, stillbirths, and newborn meningitis resulting in death.1 In 1985, an outbreak of Listeria due to soft cheese resulted in 142 individuals sick, 10 newborn deaths, 18 adult deaths, and 20 miscarriages.1 Among the immunocompromised and elderly, Listeria can cause septicemia and meningitis. In 2011, a cantaloupe outbreak due to Listeria resulted in 147 people sick in 28 states and 33 deaths.1 The infected population was mostly over the age of 65 years.1 In addition, Listeria can cause acute febrile gastroenteritis in healthy individuals.2 Patients typically present with fever, watery diarrhea, nausea, headache, and pain in joints and muscles.2 Symptoms start 24 hours after the ingestion of bacteria and resolve by themselves in 2 days.2

Treatment of Listeria depends on the severity of symptoms. Although pregnant women with Listeria infection typically present with a self-limited flu-like illness, they are treated with IV ampicillin to prevent infection of the fetus.1 For patients other than pregnant women, the treatment of Listeria infection depends on the severity of symptoms.

References

  1. Information for Health Professionals and Laboratories. (2017, June 29). Retrieved on March 1st, 2018 from https://www.cdc.gov/listeria/technical.html
  2. Say Tat Ooi, Bennett Lorber; Gastroenteritis Due to Listeria monocytogenesClinical Infectious Diseases, Volume 40, Issue 9, 1 May 2005, Pages 1327 1332, https://doi.org/10.1086/429324

 

-Ting Chen, MD is a 1st year anatomic and clinical pathology resident at the University of Vermont Medical Center.

Wojewoda-small

-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 45 Year Old Woman with Breast Abscess

Case History

Our patient is a 45-year-old female who presents to the Emergency department with breast pain. She was diagnosed with granulomatous mastitis 3 months prior. She was treated with 3 weeks of steroids, but they were stopped when the mass was unchanged and the patient was experiencing increasing breast tenderness. Since then she and has undergone several procedures to drain her right breast abscess, the most recent being five days prior. The woman has been treated with sequential courses of sulfamethoxazole–trimethoprim and metronidazole without improvement. On this visit, the abscess was again drained and sent to the microbiology laboratory for culture. The Gram stain showed no bacteria and 3+ polymorphonuclear cells. After 48 hours incubation there was scant growth on the blood agar plate and no growth on the chocolate, MacConkey or CNA plates. The colonies growing on the blood plate were tiny, white, and lipophilic (Image 1).

corynekrop1
Image 1. Small, white, lipophilic colonies growing on blood agar plate at 48 h incubation.  There was no growth of this organism on chocolate or MacConkey agars this time point.

Discussion

The organism was identified as Corynebacterium kroppenstedtii.

Colonies on the blood agar plate were identified as Corynebacterium kroppenstedtii using MALDI-TOF mass spectrometry for identification. C. kroppenstedtii is catalase positive, non-motile and a facultative anaerobe. It grows better on 5% sheep blood agar than chocolate agar, as is the case for many Corynebacterium spp. Corynebacterium come in two varieties, lipophilic such as Corynebacterium jeikeium, and luxuriantly growing, such as Corynebacterium straitum. C. kroppenstedtii is part of the former lipophilic group, forming small colonies after extended incubation.  Lipids such as Tween-80 can added to the media to improve growth of lipophilic Corynebacterium such as C. kroppenstedtii, but clinically this is not routinely performed. When viewed on a gram stain, the bacteria are rod-shaped gram positive diptheroids with typical coryneform morphology. Both MALDI-TOF and 16S rRNA sequencing can accurately identify C. kroppenstedtii to the species level.

C. kroppenstedtii is a relatively newly recognized species within the Corynebacterium genus. It was first described in a case series of young Polynesian women with histological evidence of lobar mastitis, from which C. kroppenstedtii was identified from >40% of the patients’ abscesses. Since that time, isolation of C. kroppenstedtii has been clinically associated with breast abscesses and granulomatis mastitis. C. kroppenstedtii is a highly lipophilic bacterium. Its cell wall lacks many mycolic acids, which may explain its propensity to grow in lipid-rich sites such as mammary glands. C. kroppenstedtii typically affects women of reproductive age and can be difficult to diagnose due to the slow growing nature of the lipophilic organism and the relatively few organisms present in abscess specimens.

Prior to identification by MALDI-TOF MS and 16s rRNA sequencing this patient’s culture would have been reported as rare or 1+ “dipthroid,” “coryneform,” or “Corynebacterium spp.” Without knowing the clinical significance of this organism, the culture results could easily be dismissed as contaminating skin flora.

It is very difficult to treat C. kroppenstedtii in abscesses, with the most effective treatment requiring both surgical drainage of the abscess and long term antibiotic use. It is fairly difficult to get antibiotics to the site of infection, so antibiotics that test as susceptible in the laboratory may not eradicate the pathogen. Our patient’s isolate of C. kroppenstedtii was susceptible to ciprofloxacin, clindamycin, doxycycline, and intermediate to penicillin. She remains on ciprofloxacin therapy, but has ongoing right breast tenderness. She had another surgical drainage of her breast abscess a week after this case, and the culture also grew 1+ C. kroppenstedtii with 3+ PMN seen on Gram stain, so her infection has not yet been resolved.
References

  1. Tauch, Andreas, et al. “A Microbiological and Clinical Review on Corynebacterium Kroppenstedtii.” International Journal of Infectious Diseases, vol. 48, 2016, pp. 33–39., doi:10.1016/j.ijid.2016.04.023. ScienceDirect.
  2. Johnson, Matthew G., et al. “The brief case: recurrent granulomatous mastitis due to Corynebacterium kroppenstedtii.” Journal of clinical microbiology 54.8 (2016): 1938-1941.
  3. Paviour, Sue, et al. “Corynebacterium species isolated from patients with mastitis.” Clinical Infectious Diseases 35.11 (2002): 1434-1440.

 

CW

-Carolyn Wiest, MT(ASCP) graduated from Michigan State University with a BS in molecular genetics and is a medical technologist at NorthShore University HealthSystem.  Her interests are in microbiology and molecular diagnostics. 

-Erin McElvania, PhD, D(ABMM), is the Director of Clinical Microbiology NorthShore University Health System in Evanston, Illinois.