CAN ANTIBIOTICS CHANGE THE GRAM STAIN? AN INTERESTING CASE.

Pooja Poudel, Sanjay Yadava, Kristopher Paolino, Hanish Jain, , Syracuse, NY

Meeting: Hospital Medicine 2019, March 24-27, National Harbor, Md.

Abstract number: 918

Categories: Adult, Clinical Vignettes, Hospital Medicine 2019

Keywords: ,

Case Presentation: A 45-year-old male with no known past medical history presented with a chief complaint of fever, right sided ear pain and dysphagia for 2 weeks. On presentation he was tachycardic (145/min), hypotensive (SBP in the 70s), and tachypneic (36/min). He was volume resuscitated and was empirically started on broad-spectrum antibiotics with imipenem and vancomycin due to a history of penicillin allergy. Review of the systems was unremarkable except for shortness of breath on exertion. On physical examination, he was noted to have large right palatine tonsil with purulent drainage. Laboratory evaluation revealed leukocytosis (18.5/mm3), and lactic acidosis (2.8 mg/dl). CT neck soft tissue showed right-sided peritonsillar abscess. Flexible endoscopy and incision and drainage of the right peritonsillar abscess was performed. A CT thorax with contrast was ordered for the evaluation of shortness of breath and it showed bilateral nodular lesions with cavitation consistent with septic pulmonary emboli. CT venogram of the neck was unremarkable for thrombosis or phlebitis bilaterally. Blood culture initially grew gram-positive bacilli. Cultures from the peritonsillar abscess grew Fusobacterium necrophorum and Peptostrepotococcus anaerobius. Given the clinical presentation, and the culture results from the abscess, the blood cultures were subcultured in broth for 72 hours. Repeat gram stain was performed which now showed gram-negative anaerobic rods, ultimately confirmed to be Fusobacterium necrophorum. He was diagnosed with probable Lemierre’s syndrome due to the presentation and Fusobacterium bacteremia and was given a total course of 4 weeks of antibiotics.

Discussion: Lemierre’s syndrome refers to suppurative thrombophlebitis of the jugular vein. It should be suspected in patients with a sore throat, prolonged fever and septic pulmonary emboli. The most useful test is CT scan of the neck with contrast which classically shows thrombophlebitis and thrombosis of the jugular vein. We had the high suspicion in our patient even though his CT soft tissue neck was unremarkable because of septic embolic to the lung and negative TEE. Interestingly, the initial read of gram staining discordant with our initial diagnosis as it initially stained as a gram-positive bacillus. This was felt to be due to cell wall damage attributed to prior antibiotic use prior to collecting blood cultures. Subsequent subculture and passage through broth media provided more viable organisms for accurate gram stain results.

Conclusions: Blood culture should always be drawn prior to starting antibiotics as antibiotics exposure can alter the morphology of the organism and affect the subsequent treatment. Also, we should always use our clinical judgment in a diagnosis as imaging can be deceiving sometimes as in our case CT soft tissue neck didn’t show any evidence of thrombosis or thrombophlebitis.

To cite this abstract:

Poudel, P; Yadava, S; Paolino, K; Jain, H. CAN ANTIBIOTICS CHANGE THE GRAM STAIN? AN INTERESTING CASE.. Abstract published at Hospital Medicine 2019, March 24-27, National Harbor, Md. Abstract 918. https://www.shmabstracts.com/abstract/can-antibiotics-change-the-gram-stain-an-interesting-case/. Accessed December 15, 2019.

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