Case Presentation: A 57-year-old man with past medical history of hypertension and left partial nephrectomy for renal cell carcinoma presented to the emergency department with several days of fevers, diarrhea, and fatigue. On examination, the patient was lethargic and febrile to 103°F with a blood pressure of 80/50mmHg. His labs were notable for an elevated serum lactic acid of 2.06 with the remainder of labs otherwise unremarkable. Given complaints of diarrhea, a CT of his abdomen was performed showing enterocolitis. The patient was admitted for concern of sepsis and a set of blood cultures were collected on admission that ultimately grew Staphylococcus hyicus. He was started on fluids and IV Vancomycin resulting in improvement in his clinical condition. A subsequent trans-thoracic echocardiogram (TTE) and trans-esophageal echocardiogram (TEE) were negative for endocarditis.
After the cultures grew this unusual organism, the patient was questioned more pointedly. He admitted recently visiting a farm where sausage had just been made from feral hogs. He had eaten the sausage just days prior to onset of illness and he further reported that he had undergone extensive dental work just prior to that meal. This additional history helped explain how the patient may have been infected from bacterial translocation/seeding to the blood.
Discussion: About eight species of coagulase-positive staphylococcus have been mentioned. The most familiar pathogen is Staphylococcus aureus, while the remainder of the pathogens are known primarily in veterinary medicine. S. hyicus is a part of the natural flora of several animals. It is mainly involved in exudative epidermitis in pigs but has also been isolated from skin infections in horses, mastitis in cows, and even from a human wound infection from a donkey bite. It is a coagulase-variable species that has components of both coagulase positive and negative isolates. It is important to note that S. hyicus can be misidentified as S. aureus or coagulase-negative staphylococci. To ensure correct species identification, it is important for clinicians to obtain thorough patient history as well as collaborate with microbiologists if clinical nor laboratory findings are typical for S. aureus.
On our review of literature, there was only one other case of S. hyicus bacteremia in a patient who came in close contact with his piglets. In our case, the patient’s presumed source of infection came from consumption of wild hog meat after recent dental work.
This case highlights several important points for clinical practice when making the diagnosis. First, it is important to note that S. hyicus can present as sepsis in humans, especially those that are immunocompromised. Second, a thorough history is imperative to help with the clinical diagnosis. Third, S. hyicus is often misidentified as S. aureus. Therefore, further investigation is indicated in zoonotic staphylococcal infections to ensure correct species identification.
Conclusions: Staphylococcus hyicus has rarely been reported to cause infections in humans. It is otherwise a well known cause of diseases in a variety of animals. It is important for clinicians to be aware that S. hyicus can present as sepsis in humans and a thorough history is imperative to help with the diagnosis of zoonotic staphylococcal infections.