Spontaneous nocardial brain abscess in a juvenile rhesus macaque (Macaca mulatta).

BACKGROUND: A juvenile rhesus macaque presented with blindness, ataxia, and head tilt. METHODS: Postmortem gross and microscopic examination, histochemical staining and bacterial culture were performed. RESULTS: Nocardia sp. was identified as the etiologic agent of a primary pneumonia with secondary cerebral abscessation. CONCLUSIONS: Nocardiosis should be a differential diagnosis for patients with neurologic disease.

Intracage ammonia levels in static and individually ventilated cages housing C57BL/6 mice on 4 bedding substrates.

The relationship among ammonia levels, cage-changing frequency, and bedding types is an important and potentially controversial topic in the laboratory animal science community. Some bedding options may not provide sufficient urine absorption and bacterial regulation to minimize ammonia production during the interval between cage changes. High intracage ammonia levels can cause subclinical degeneration and inflammation of nasal passages, rhinitis and olfactory epithelial necrosis in exposed mice. Here we sought to compare the effects of 4 commonly used bedding substrates (1/4-in. irradiated corncob, reclaimed wood pulp, aspen wood chips, and recycled newspaper) on ammonia generation when housing female C57BL/6 mice in static and individually ventilated caging. Intracage ammonia levels were measured daily for 1 wk (static cage experiment) or 2 wk (IVC experiment). The results of this study suggest that the corncob, aspen wood chip, and recycled newspaper beddings that we tested are suitable for once-weekly cage changing for static cages and for changing every 2 wk for IVC. However, ammonia levels were not controlled appropriately in cages containing reclaimed wood pulp bedding, and pathologic changes occurred within 1 wk in the nares of mice housed on this bedding in static cages.

Efficacy of oral fecal bacteriotherapy in rhesus macaques (Macaca mulatta) with chronic diarrhea.

Chronic diarrhea remains the principal burden in providing health care for nonhuman primates in biomedical research facilities. Although the exact etiology continues to puzzle nonhuman primate clinicians, recent research in humans has shown that restoring the indigenous microbial diversity may be successful in resolving cases of chronic diarrhea when other treatment modalities have failed. The process of restoring this microbial balance, known as fecal bacteriotherapy, uses the complete flora from a normal donor as a therapeutic probiotic mixture. In the current study, Indian-origin rhesus macaques were randomized into treatment (n=7) and control (n=6) groups to determine whether orally administered fecal bacteriotherapy would reduce the overall incidence of chronic diarrhea during a 60-d follow-up period in the treatment group compared with control macaques, which received a placebo. Although the treatment effect, determined by comparing the baseline fecal scores of the treatment and control groups, did not reach statistical significance, preprocedure and postprocedure fecal scores in the treatment group differed significantly. These findings are encouraging, and we hope that our study will motivate larger studies evaluating the use of fecal bacteriotherapy in nonhuman primates.

An outbreak of tularemia in a colony of outdoor-housed rhesus macaques (Macaca mulatta).

Since an epizootic and detection of clinical cases of tularemia (Francisella tularensis) in 1996 at the Oregon National Primate Research Center, only 8 cases were identified in the succeeding 13 y. However, within a period of 7 mo, primarily during Winter 2010, 6 rhesus macaques were confirmed positive for Francisella tularensis type B by the Centers for Disease Control and Prevention by culture and fluorescent antibody testing. All cases had similar gross pathologic findings, which included necrotizing splenitis and lymphadenitis. Recent colony management efforts have focused on minimizing nonhuman primate exposure to commonly observed reservoir species and controlling rodent access to corral-style housing. Strategies continue to evolve with regard to managing a large breeding colony of nonhuman primates in the presence of this threat.