Gastric Perforation and Peritonitis Associated With Sarcina Sp. Infection in a Previously Healthy Patient: Case Report of a Rare and Potentially Fatal Infection

The genus Sarcina comprises Gram-positive, anaerobic bacteria characterized morphologically by cubic packets. Among its species, Sarcina ventriculi stands out for its ability to survive in environments with extremely low pH, such as the stomach. Although its pathogenicity is not fully established, the presence of this bacterium is associated with gastric motility disorders and mucosal lesions, which act as predisposing factors for complications. This report describes a case of gastric ulcer perforation in a previously healthy patient, associated with Sarcina sp. infection, evolving to perforated acute abdomen and peritonitis. A 59-year-old male, hypertensive and a smoker, with a history of gastric ulcer, was admitted with sudden, intense abdominal pain, without vomiting or changes in bowel habits. On physical examination, blood pressure was 175/109 mmHg, heart rate 111 bpm, and the abdomen was distended, rigid and tender, with predominance in the epigastric region. X-Ray showed pneumoperitoneum. He underwent exploratory laparotomy, which identified a gastric perforation in the lesser curvature, and omental patch repair of the ulcer was performed. In the postoperative period, he developed purulent drainage through the surgical drain, requiring reoperation for abdominal cavity lavage, with subsequent good clinical evolution. Histopathological examination revealed connective and muscle tissue with fibrinoleukocytic exudate, scant necrotic epithelium and bacterial structures compatible with Sarcina sp. The patient was discharged on treatment for H. pylori and outpatient follow-up. Infection by Sarcina sp. is rare, with fewer than 70 cases documented in the literature. A recent review indicates a need for surgical intervention in 23% of cases and a mortality rate of 14%. This case draws attention to comorbidities and previous ulcer disease as likely contributing factors to bacterial proliferation. Despite the absence of specific guidelines, the use of broad-spectrum antibiotics associated with proton pump inhibitors is recommended, with a reported therapeutic success rate of 88%. This case reinforces the importance of including Sarcina sp. in the differential diagnosis of severe gastrointestinal tract complications, even in the absence of classic risk factors, and highlights the role of histopathological examination in guiding management.