Article

Dear Editor-in-Chief,

Sarcina ventriculi is an easy-to-identify Gram-positive bacteria because of its distinct morphological characteristics. The bacterium derived its name from the Latin word “Sarcina” meaning “package”, due to its characteristic formation in groups of four or eight, basophilic staining, and refractive properties under light microscopy ¹. Microorganisms like these can be found on the surface of gastric mucosa and are not pathogenic. Several clinical associations include abdominal pain, food bezoars, and gastric ulcers ¹. It can also manifest as diabetic gastroparesis, gastric scarring and pyloric stenosis ¹. Individuals who consume a predominantly vegetarian diet have also been found to contain Sarcina ventriculi in their feces ¹. It has been associated with gastric perforation, emphysematous gastritis, peritonitis, and gastric adenocarcinoma, even though its mechanism of action is unknown ¹.

We report the cases of two patients with Sarcina ventriculi associated gastritis. Our first case was a 35-year-old male with clinical symptoms of gastroesophageal reflux disease for the past five years. Impression on esophagogastroduodenoscopy (EGD) was of moderate to severe gastritis in body and antrum of the stomach. Histology of our first case showed small spherical micro-organisms in a tetrad arrangement present in inflammatory exudate as represented in Figure 1 A. A positive immunostaining for Helicobacter pylori was found in our first cases with moderate Helicobacter pylori colonization, as represented in Figure 1 B.

In our second case, a 60-year-old man had been suffering from vomiting, abdominal pain, anorexia, and weight loss for two months. Esophagogastroduodenoscopy (EGD) demonstrated a large ulcerated growth in the antrum. Clinical impression was of gastric carcinoma. The presence of Sarcina ventriculi was detected in gastric biopsy, as represented in Figure 1 C and Figure 1 D. There was no evidence of intestinal metaplasia, dysplasia, or malignancy.

Sarcina ventriculi is an anaerobic, gram-positive coccus which also goes by the name Clostridium ventriculi ¹. The sole energy source of the organism is carbohydrate fermentation ¹. Low pH and highly acidic environments are compatible with its growth ¹. Biopsies stained with hematoxylin and eosin (H&E) are used to diagnose it. Tetrads can be formed by Micrococcus as well, although they are considerably smaller ¹. There is a resemblance between the thick walls of Sarcina ventriculi and fungi or vegetable matter in silver stain¹. In addition to gastric biopsies, blood samples and gastric brushing cytology samples have also been screened for positive results ². Apart from esophageal stricture and emphysematous gastritis, they have also has also been linked to fatal perforations ¹. Co-infection by Helicobacter pylori and Sarcina ventriculi in the same patient, as seen in our first case, have only been previously reported in two case reports ¹.

An emphysematous gastritis caused by Sarcina ventriculi was described in a case report by Kevin Singh in 2019 ³. The patient suffered hematemesis and hemodynamic instability and unfortunately died despite extensive resuscitation³. An episode of acute colonic pseudo-obstruction was documented by Bortolotti et al. ⁴ that was followed by bacteremia caused by Sarcina ventriculi.

Given its documented associations and potential complications, it is crucial for pathologists to recognize the histology of Sarcina ventriculi on routine hematoxylin and eosin (H&E) slides and provide relevant information for the patient’s ongoing management and treatment. Varying options have been suggested in different case reviews, highlighting the necessity for further research in this area. Antibiotic treatment is considered the treatment of choice to prevent complications⁵.

CONFLICTS OF INTEREST

The authors declare no conflict of interest.

FUNDING

All authors have declared that no financial support was received from any organization for the submitted work.

ETHICAL CONSIDERATION

Exemption letter of ethical approval was obtained from the Institutional Review Board (IRB) of Chughtai Institute of Pathology, Lahore, Pakistan. The reference number of the letter from Institutional Review Board (IRB) is CIP/IRB/1222. Written informed consent was obtained from each patient for anonymized publication of data from the clinical report.

Figures and tables

Figure 1.(A) Small spherical microorganisms in a tetrad-arrangement present in the inflammatory exudate in our first case are encircled. (Hematoxylin and eosin stain, x400 magnification). (B) Immunohistochemical staining for Helicobacter pylori in our case 1 are highlighted by arrowheads. (x400 magnification). (C-D) Sarcina ventriculi organisms in gastric biopsy in our second case are encircled. (Hematoxylin and eosin stain, x400 magnification).

References

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3. Singh K. Emphysematous Gastritis Associated with Sarcina ventriculi. Case Rep Gastroenterol. 2019; 13:207-213. DOI
4. Bortolotti P, Kipnis E, Faure E. Clostridium ventriculi bacteremia following acute colonic pseudo-obstruction: A case report. Anaerobe. 2019; 59:32-34. DOI
5. Birkholz T, Kim GJ, Niehaus H. Non-operative Management of Sarcina ventriculi-Associated Severe Emphysematous Gastritis: A Case Report. Cureus. 2022; 14:e31543. DOI