Introduction: Staphylococcus aureus is the leading cause of hospital- and community-acquired bacteremia.

Case Presentation: A 48-year-old immunocompetent man with hypertension was admitted for a 2-day history of abdominal pain radiating to the pelvis and dyspnea since recently flying domestically. Additional history revealed diaphoresis, dyspnea, nausea, vomiting, and non-bloody diarrhea 2-3 hours following a large meal upon arrival. Examination demonstrated diffuse abdominal tenderness to palpitation and distension. Of significant note, patient has had significant upper periodontal swelling for past few weeks. On admission, he was tachycardiac to 100s and was placed on 3 liters oxygen nasal cannula. CT chest identified peripheral wedge-shaped consolidations suggestive of multifocal infectious process consistent with septic emboli. EKG showed sinus tachycardia with S1Q3T3 pattern. Peripheral blood cultures were positive for methicillin-sensitive Staphylococcus aureus (MSSA). His hospital course was prolonged and complicated by orbital cellulitis and bilateral empyema. Additionally, he developed acute hypoxic respiratory failure causing him to decompensate and requiring intubation. Heparin drip was initiated after clinical suspicion of pulmonary emboli on admission. Patient was put on intravenous (IV) Ancef after initial positive blood culture for MSSA. Upon discharge, the final treatment plan for this patient is IV Ancef for an additional 6 weeks via PICC line infusion in his home state.

Working Diagnosis: The source of his MSSA bacteremia still remains unknown, but we suspect it was caused by his empyema secondary to septic emboli, prompting further investigation. The etiology of his septic emboli could have been: -Periodontal abscess, related to reported history of upper gum swelling of a few weeks prior to presentation;

-Infected upper-extremity hardware, as this patient carries history of ORIF;

-Infected intravenous line, a common source of hospital-acquired infection;

-Foodborne illness on arrival after prolonged immobility on a plane; or

-Endocarditis, though unlikely as echocardiogram was negative for valvular vegetations.

Future Outlook: MSSA bacteremia has frequently been reported to be associated with deep tissue infection, but rarely has it been associated with empyema secondary to septic emboli. It is important to determine the etiology and appropriate medical management for patients with MSSA bacteremia.

References

10. Y. Tong, J. S. Davis, E. Eichenberger, T. L. Holland, and V. G. Fowler, Jr., “Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management,” Clin Microbiol Rev, vol. 28, no. 3, pp. 603-61, Jul 2015, doi: 10.1128/CMR.00134-14.
11. Y. Lin, K. Rezai, and D. N. Schwartz, “Septic pulmonary emboli and bacteremia associated with deep tissue infections caused by community-acquired methicillin-resistant Staphylococcus aureus,” J Clin Microbiol, vol. 46, no. 4, pp. 1553-5, Apr 2008, doi: 10.1128/JCM.02379-07.