Microbiology Case Study: A 17 Year Old with Chest Pain

Case History

A 17 year old female who presented to the emergency department with complaints of fever, vomiting, diarrhea, and chest pain for the past two weeks. She also reported an unintentional weight loss of 20 lbs. Her medical history consisted of essential hypertension for which she was previously on medication, however had been discontinued two years ago due to normal blood pressure. The patient reported that she is sexually active with one male partner and denied use of protection. She denied any other sexual partners or any prior history of sexually transmitted infections. Her urine NAAT testing was positive for chlamydia, but negative for gonorrhea. Blood cultures collected at the time of admission resulted in growth of gram-negative diplococci on day 2 of admission (Image 1) and colony growth on chocolate agar (Image 2). The organism was positive for both catalase and oxidase and identified by matrix-assisted light desorption ionization- time of flight (MALDI-TOF) as Neisseria gonorrhoeae. Due to her chest pain complaints and QT prolongation on EKG, a trans-thoracic echo was performed that demonstrated a large aortic root abscess suggestive of infective endocarditis. Ceftriaxone was started as treatment for her gram-negative endocarditis, and she was emergently transferred to another facility where an aortic valve replacement and patch aortoplasty were performed.

Image 1. Gram stain of the blood culture showing gram negative diplococci.
Image 2. Neisseria gonorrhoeae on chocolate agar producing small gray-white colonies.

Discussion

Neisseria gonorrhoeae is a fastidious, oxidase positive, gram negative diplococcus, commonly transmitted through sexual contact.2,3 Neisseria uniquely grows on chocolate agar and VPN/Thayer Martin agar, and has virulence factors such as pilli that attach to mucosal surfaces, and many antigenic variations that make it a highly resistant organism prone to reinfection.

In the laboratory, N. gonorrhea grows well on chocolate agar after 24-48 hours of incubation (Image 2) with less robust or no growth on blood agar. It is positive for both catalase and oxidase. Traditionally, sugar fermentation was used to differentiate Neisseria species from one another, but more ore rapid identification methods (MALDI-TOF and PCR) are being increasingly used in most clinical laboratories

In men, Neisseria usually ascends the genitourinary tract to cause prostatitis. In women, the infection can disseminate to cause pelvic inflammatory disease, which can cause scarring in the fallopian tubes, resulting in infertility. Neisseria also can present as an asymmetric polyarthritis, most commonly to the knees. The main treatment of Neisseria gonorrhea is ceftriaxone. Gentamicin is an acceptable alternative in patients with severe cephalosporins allergy.

This case involves a rare presentation of infective endocarditis caused by disseminated gonorrhea infection. Previous reported cases of gonococcal endocarditis1,4 reported ad subacute presentation in around 2-4 weeks with generalized fatigue, fevers, arthritis, rash, renal dysfunction, and new cardiac murmurs. Because it can present without preceding genitourinary symptoms, disseminated gonorrheal can be difficult to recognize. The infection is usually aggressive, forming large vegetations and rapid valve destruction, despite antibiotic treatment. Most commonly it involves the aortic valve, as seen in the case presented above, but can also involve the mitral and tricuspid valves in some cases. The damage usually requires valve replacement surgery in addition to antimicrobial therapy.5,6 Lastly, this case demonstrates the limitations of the urine NAAT to diagnose gonorrhea specifically in females and/or asymptomatic patients due the possible presence of inhibitors and the need for further testing if clinical suspicion remains.7

References

  1. Said M, Tirthani E. Gonococcal Infective Endocarditis Returns. Cureus. 2021 Sep 14;13(9):e17955. doi: 10.7759/cureus.17955. PMID: 34660143; PMCID: PMC8515499.
  2. Ryan, K. J., Ray, G., and Sherris, J. C. (2004). Sherris Medical Microbiology: An introduction to Infectious Diseases, 4th edition. McGraw-Hill Medical.
  3. Centers for Disease Control and Prevention. Gonorrhea. Available from: https://www.cdc.gov/std/gonorrhea/stdfact-gonorrhea-detailed.htm. Last updated 2021 July 22; cited on 2022 March 21.
  4. Fenech, Marylou, et al. “Neisseria Gonorrhoeae Infective Endocarditis.” BMJ Case Reports, BMJ Specialist Journals, 1 May 2022
  5. Thompson EC, Brantley D. Gonoccocal endocarditis. J Natl Med Assoc. 1996 Jun;88(6):353-6. PMID: 8691495; PMCID: PMC2608094.
  6. Nie S, Wu Y, Huang L, Pincus D, Tang YW, Lu X. Gonococcal endocarditis: a case report and literature review. Eur J Clin Microbiol Infect Dis. 2014 Jan;33(1):23-7. doi: 10.1007/s10096-013-1921-x. Epub 2013 Jul 16. PMID: 23856883.
  7. Whiley DM, Tapsall JW, Sloots TP. Nucleic acid amplification testing for Neisseria gonorrhoeae: an ongoing challenge. J Mol Diagn. 2006 Feb;8(1):3-15. doi: 10.2353/jmoldx.2006.050045. PMID: 16436629; PMCID: PMC1871692.

-Olivia Piscano is a second-year medical student at the Medical College of Georgia. She is currently interested in Internal Medicine, Pediatrics, and Infectious Disease.

-Hasan Samra, MD, is the Director of Clinical Microbiology at Augusta University and an Assistant Professor at the Medical College of Georgia.

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