Management of reactive arthritis in a juvenile gorilla (Gorilla gorilla gorilla) with long-term sulfasalazine therapy

MULTISPECIES SHIGELLA FLEXNERI OUTBREAK IN A ZOOLOGICAL COLLECTION COINCIDING WITH A CLUSTER IN THE LOCAL HUMAN POPULATION

Shigella flexneri is a nonmotile gram-negative bacillus that affects humans and nonhuman primates. In August 2021, 15 primates at the ABQ BioPark demonstrated clinical signs of Shigella infection: 3 out of 4 Sumatran and hybrid orangutans (Pongo abelii), 6 out of 8 gorillas (Gorilla gorilla), 2 out of 9 chimpanzees (Pan troglodytes), and 4 out of 4 siamangs (Hylobates syndactylus). Three siamangs and one gorilla succumbed to complications of shigellosis during the initial outbreak and a chimpanzee died 10 mon later. Although it is well documented that Shigella may cause morbidity and mortality in nonhuman primates, the rapid and devastating nature of the outbreak, the difference from previous reports in zoological collections (enzootic vs outbreak), and the chronological overlap with the increase in human cases in the region makes discussion of this Shigella outbreak of significance. The cases presented here are significantly different than previous reports, because these were part of an outbreak that arose and subsided, versus other reports where the authors describe an enzootic disease with persistently infected animals. Close communication with the New Mexico Department of Health allowed for the investigation into possible sources of the outbreak, recommendations regarding biosecurity protocols, and staff education.

Intestinal Flora Modification of Arthritis Pattern in Spondyloarthropathy

BACKGROUND

The reactive form of spondyloarthropathy appears inducible by exposure to agents of infectious diarrhea, but do those organisms represent the tip of the iceberg, as indicated by renewed interest in gastrointestinal flora? Prevalence of spondyloarthropathy (20% of chimpanzees [Pan] and 28% of gorillas) is independent of subspecies and species, respectively. However, there are major differences in arthritis patterns, a characteristic shared with humans.

OBJECTIVES

Do patterns of arthritis correlate with gastrointestinal flora? Could such associated modifications be in the form of disease induction or represent protective effectors (at least against the extent of peripheral arthritis)?

METHODS

The skeletons of 2 chimpanzee subspecies (79 Pan troglodytes troglodytes and 26 Pan troglodytes schweinfurthii) and 2 gorilla species (99 Gorilla gorilla and 38 Gorilla beringei) adults were examined, and arthritis pattern noted. Feces of Eastern (P. schweinfurthii and G. beringei) and Western (great apes collected in their normal ranges) apes were assessed for 16S rRNA c and its character.

RESULTS

Patterns of arthritis recognized on examination of skeletons showed geographic variation in skeletal distribution. East African apes (P. troglodytes schweinfurthii and G. beringei) had pauciarticular arthritis and frequent sacroiliac disease, whereas West African apes (P. troglodytes troglodytes and G. gorilla) had polyarticular peripheral joint disease with minimal sacroiliac involvement. DNA evidence revealed that Corynebactericeae were prominently represented in great apes with polyarticular disease, whereas Dietzia and Bifidobacterium exposure correlated with reduced peripheral joint arthritis distribution.

CONCLUSIONS

Suggestions of a protective effect (in this case, limiting extent of peripheral arthritis, but not the disease itself) offered by these organisms are well represented by documented effects in other diseases (eg, tuberculosis) in the zoologic record. Perhaps it is this disease-modifying character that reduces the extent of the peripheral erosive disease, while increasing propensity to axial (sacroiliac) disease. A potential role for probiotic organisms in management of arthritis in humans is suggested, as has been documented for tuberculosis, gastrointestinal disorders, and food allergies.

Comparative Pathology of Aging Great Apes: Bonobos, Chimpanzees, Gorillas, and Orangutans

The great apes (chimpanzees, bonobos, gorillas, and orangutans) are our closest relatives. Despite the many similarities, there are significant differences in aging among apes, including the human ape. Common to all are dental attrition, periodontitis, tooth loss, osteopenia, and arthritis, although gout is uniquely human and spondyloarthropathy is more prevalent in apes than humans. Humans are more prone to frailty, sarcopenia, osteoporosis, longevity past reproductive senescence, loss of brain volume, and Alzheimer dementia. Cerebral vascular disease occurs in both humans and apes. Cardiovascular disease mortality increases in aging humans and apes, but coronary atherosclerosis is the most significant type in humans. In captive apes, idiopathic myocardial fibrosis and cardiomyopathy predominate, with arteriosclerosis of intramural coronary arteries. Similar cardiac lesions are occasionally seen in wild apes. Vascular changes in heart and kidneys and aortic dissections in gorillas and bonobos suggest that hypertension may be involved in pathogenesis. Chronic kidney disease is common in elderly humans and some aging apes and is linked with cardiovascular disease in orangutans. Neoplasms common to aging humans and apes include uterine leiomyomas in chimpanzees, but other tumors of elderly humans, such as breast, prostate, lung, and colorectal cancers, are uncommon in apes. Among the apes, chimpanzees have been best studied in laboratory settings, and more comparative research is needed into the pathology of geriatric zoo-housed and wild apes. Increasing longevity of humans and apes makes understanding aging processes and diseases imperative for optimizing quality of life in all the ape species.

Primate spondyloarthropathy

Spondyloarthropathy is a common occurrence in Old World primates, with only limited presence in New World monkeys. Clearly distinguished from rheumatoid arthritis, this erosive arthritis afflicts 20% of great apes, baboons, and rhesus macaques and had been increasing in frequency. Habitat-dependent infectious agent diarrhea-induced reactive arthritis is implicated on a background of genetic predisposition. A gorilla-derived therapeutic preventative approach has possible application in human clinical medicine.

Comparison of arthritis characteristics in lowlandGorilla gorilla and mountainGorilla beringei

Gorilla gorilla and the less-studied G. beringei occupy very different, geographically separate habitats. We studied the occurrence of various forms of arthritis to examine possible nature/nurture causality. The macerated skeletons of 38 G. beringei and 99 G. gorilla individuals were examined macroscopically for the presence of articular and osseous pathologies. Contrasting with only isolated osteoarthritis and infectious arthritis was the frequent occurrence of a form of erosive arthritis associated with joint fusion. Twenty-one percent of the G. beringei and 20% of G. gorilla specimens were afflicted, which are statistically indistinguishable frequencies. While both had prominent axial disease, they differed in patterns of peripheral arthritis. Whereas G. beringei showed a pauciarticular pattern, the pattern in G. gorilla was more often polyarticular. Susceptibility to spondyloarthropathy was apparently genetically imprinted before Gorilla separated into G. gorilla and G. beringei. However, the different patterns of peripheral joint involvement suggest a causality resulting from lifestyle (e.g., the presence/absence or extent of knuckle walking) or a habitat-related infectious agent.

Meat‐Adaptive Genes and the Evolution of Slower Aging in Humans

The chimpanzee life span is shorter than that of humans, which is consistent with a faster schedule of aging. We consider aspects of diet that may have selected for genes that allowed the evolution of longer human life spans with slower aging. Diet has changed remarkably during human evolution. All direct human ancestors are believed to have been largely herbivorous. Chimpanzees eat more meat than other great apes, but in captivity are sensitive to hypercholesterolemia and vascular disease. We argue that this dietary shift to increased regular consumption of fatty animal tissues in the course of hominid evolution was mediated by selection for "meat-adaptive" genes. This selection conferred resistance to disease risks associated with meat eating also increased life expectancy. One candidate gene is apolipoprotein E (apoE), with the E3 allele evolved in the genus Homo that reduces the risks for Alzheimer's and vascular disease, as well as influencing inflammation, infection, and neuronal growth. Other evolved genes mediate lipid metabolism and host defense. The timing of the evolution of apoE and other candidates for meat-adaptive genes is discussed in relation to key events in human evolution.