sarcin

Sarcina is a genus of bacteria best known for its distinctive cellular arrangement: the cells tend to form cubical packets, often described as tetrads or larger clusters of eight or more cells. This characteristic packing results from division in three perpendicular planes and gives Sarcina its recognizable microscopic appearance.

Morphology and biology: Sarcina cells are typically small, Gram-positive cocci that are non-motile and non-spore-forming. They thrive in environments with low oxygen tension and can tolerate acidic conditions. The genus includes species that have been found in the stomachs of animals and, on rare occasions, in human gastric samples. Cultivation in laboratory settings is challenging, which has limited extensive profiling of their physiology outside natural habitats.

Habitat and distribution: In nature, Sarcina species have been isolated from the gastrointestinal tracts of ruminants and other animals. In humans, the best-documented member is Sarcina ventriculi, which has appeared in gastric biopsy specimens from individuals with various gastric disturbances. The organism is infrequently encountered in clinical practice, and its role as a pathogen versus a incidental colonizer is not fully established.

Clinical relevance: In human cases, Sarcina ventriculi has been associated with gastric conditions such as delayed gastric emptying, gastritis, or ulcers, but causality remains uncertain. Diagnosis is typically made histologically by observing the characteristic cubical arrangements in tissue samples; culture methods are not routinely used due to difficulty in growing the organism. When identified, treatment decisions are guided by the patient’s clinical condition and often involve standard management of underlying gastric disease; antibiotics have been used in some reported cases, though there is no universally accepted protocol.

Etymology and history: The name Sarcina derives from Latin for “pack” or “bundle,” reflecting the clustering of cells. The genus was described in the 19th century, with Sarcina ventriculi among the most studied species in human-associated contexts.