Klebsiella sp.-related infectious spondylitis in a bearded dragon (Pogona vitticeps)

Bone infection evolution

The present minireview aims to provide a context for imagination of the timespan for bone infection evolution from the origin of cellular bone tissue to modern orthopedic surgery. From a phylogenetic osteomyelitis-bracketing perspective, and due to the time of osteocyte origin, bacteria might have been able to infect the skeleton for approximately 400 million years. Thereby, bone infections happened simultaneously with central expansions of the immune system and development of terrestrial bone structure. This co-evolution might aid in explaining the many immune evasion strategies seen in the field of bone infections. Bone infection patients with long disease-free periods followed by sudden recurrence and anamnesis of long-term and low-grade infections indicate that bacteria can perform silent parasitism within bone tissue (parasitism; one organism lives on another organism, the host, causing it harm and is structurally adapted to it). The silence seems to be disturbed by immunosuppression and the present minireview shows that a compromised immune system has been associated with bone infection development across all species in the phylogenetic tree. Orthopedic surgery, including arthroplasty and osteosynthesis, favor introduction of bacteria and prosthesis/implant related infections are thus anthropogenic infections (anthropogenic; resulting from the influence of human beings on nature). In that light it is important to remember that the skeleton and immune system have not evolved for millions of years to protect titanium alloys and other metals, commonly used for orthopedic devices from bacterial invasion. Therefore, these relatively new orthopedic infection types must be seen as distinct with unique implant/prosthesis related pathophysiology and immunology.

Unusual lesions seen in the caudals of the hadrosaur, Edmontosaurus annectens

The study of pathologies in the fossil record allows for unique insights into the physiology, immunology, biomechanics, and daily life history of extinct organisms. This is especially important in organisms that have body structures dissimilar to those of extant organisms as well as transitional groups whose extant relatives may have very dissimilar physiologies. Comparisons between modern groups and their fossil ancestors are further complicated by the fact that fossil groups may have experienced unique biomechanical stresses as well as possessing a mixture of anatomical features seen in their related extant groups. In this study, we present lesions in the caudal vertebrae of the hadrosaur, Edmontosaurus annectens from the Ruth Mason Dinosaur Quarry of South Dakota, which exhibit unique morphologies. X-ray microtomography was performed on the most extreme example of this morphology to allow for both a detailed and more accurate diagnosis of the pathologic condition as well as virtual conservation of the specimen. Based on the location, the overall morphology of the lesion, and the relative "normal" appearance of the internal microstructure, the most probable cause is postulated as long-term biomechanical stresses exerted on this section of the tail by both lateral and dorsoventral motions of the tail. This deduction was based on a process of elimination for a variety of known osteological conditions; however, future work is needed to determine the nature of the stresses and why this condition has not been recorded in more hadrosaurian specimens.

Wild microbiomes of striped plateau lizards vary with reproductive season, sex, and body size

Long-term studies of animal microbiomes under natural conditions are valuable for understanding the effects of host demographics and environmental factors on host-associated microbial communities, and how those effects interact and shift over time. We examined how the cloacal microbiome of wild Sceloporus virgatus (the striped plateau lizard) varies under natural conditions in a multi-year study. Cloacal swabs were collected from wild-caught lizards across their entire active season and over three years in southeastern Arizona, USA. Analyses of 16S rRNA data generated on the Illumina platform revealed that cloacal microbiomes of S. virgatus vary as a function of season, sex, body size, and reproductive state, and do so independently of one another. Briefly, microbial diversity was lowest in both sexes during the reproductive season, was higher in females than in males, and was lowest in females when they were vitellogenic, and microbiome composition varied across seasons, sexes, and sizes. The pattern of decreased diversity during reproductive periods with increased sociality is surprising, as studies in other systems often suggest that microbial diversity generally increases with sociality. The cloacal microbiome was not affected significantly by hibernation and was relatively stable from year to year. This study highlights the importance of long term, wide-scale microbiome studies for capturing accurate perspectives on microbiome diversity and composition in animals. It also serves as a warning for comparisons of microbiomes across species, as each may be under a different suite of selective pressures or exhibit short-term variation from external or innate factors, which may differ in a species-specific manner.

Diagnostic Clinical Pathology of the Bearded Dragon (Pogona vitticeps)

The bearded dragon (Pogona vitticeps), an omnivorous Agamid lizard native to inland Australia, is one of the most popular reptile pets due to their sociable behavior, tame demeanor, low-maintenance care, and relative ease of breeding. Because they are generally stoic animals, thorough physical examination in conjunction with routine clinicopathologic data can prove invaluable in identifying disease and implementing appropriate therapy in a timely manner. The goal of this article is to assist the practicing clinician, based on literature review, on how to approach the diagnostic challenge encountered in everyday practice when working up various conditions in bearded dragons.

A Case of Submandibular Leiomyosarcoma, Mimicking an Abscess, in a Ball Python (Python regius)

A two-year-old ball python with a submandibular mass was evaluated. Fine needle aspiration resulted in debris containing purulent materials and bacterial cells on cytology. Radiography demonstrated multi-focal radiopaque lesions in the mass, which were suspected to be mineralization; there was an absence of mandibular invasion or lung involvement. Gross examination of the surgically excised mass revealed a multi-nodular, well-circumscribed lesion with purulent material. The postoperative recovery was uneventful. The histopathological examination followed by immunohistochemistry analysis gave a diagnosis of leiomyosarcoma. As tumors containing purulent materials can be confused with an abscess, diagnostic confirmation with various diagnostical tools should be considered.