Sarcina sp. as a presumptive cause of fatal acute gastric dilation and gastric emphysema in rhesus macaques

Abstract

A 4-y-old female and 3-y-old male rhesus macaque ( Macaca mulatta), both housed in the same facility, died unexpectedly within 2 wk. Postmortem examination revealed severe gastric dilation in both macaques and gastric emphysema in the female macaque. Histologically, bacteria consistent with Sarcina sp. were present in both macaques within the lungs and lumen of the trachea, esophagus, and gastrointestinal (GI) tract without associated inflammation. Additionally, in the female macaque, the bacteria were found in the gastric mucosa and associated with emphysematous spaces in the gastric wall without associated inflammation. PCR and Sanger sequencing of amplicons were subsequently performed on GI contents and non-alimentary tissues from the 2 affected monkeys and on comparative samples from unaffected rhesus monkeys in the same facility and an adjacent primate facility. The cases were compared using the 2-tailed Fisher exact test ( p-value at 95% confidence). PCR identified Sarcina in GI contents of both affected and unaffected monkeys ( p = 0.6084) and in non-alimentary tissues of affected monkeys only ( p = 0.0083). These results suggest that the presence of Sarcina sp. in non-alimentary tissues is associated with gastric distension, gas accumulation, and unexpected death in nonhuman primates.