Leatherback turtles () are endangered by anthropogenic threats. Characterizing the physiologic response of leatherback turtles under various stressors may inform conservation strategies. In this study, a commercially available enzyme immunoassay for aldosterone was validated for leatherback turtle plasma, and it was used with previously validated assays for corticosterone and free thyroxine (fT4) to evaluate the physiologic status of leatherback turtles that were entangled in fishing gear, stranded on shore, nesting or intentionally captured at sea during ecologic studies.
View Article and Find Full Text PDFObjective: To describe the presentation, clinical findings, diagnosis, treatment, and outcome of cases of trismus (lockjaw) in cold-stunned sea turtles.
Animals: 4 Kemp's ridley (Lepidochelys kempii) and 1 loggerhead (Caretta caretta) sea turtle.
Methods: Cold-stunned sea turtles that presented with difficulty or inability to open their jaw between 2009 and 2023 were included.
Proc Natl Acad Sci U S A
March 2024
Enterococci are gut microbes of most land animals. Likely appearing first in the guts of arthropods as they moved onto land, they diversified over hundreds of millions of years adapting to evolving hosts and host diets. Over 60 enterococcal species are now known.
View Article and Find Full Text PDFSensing small molecules is crucial for microorganisms to adapt their genetic programs to changes in their environment. Arrest peptides encoded by short regulatory open reading frames program the ribosomes that translate them to undergo translational arrest in response to specific metabolites. Ribosome stalling in turn controls the expression of downstream genes on the same messenger RNA by translational or transcriptional means.
View Article and Find Full Text PDFEach year in the United States, thousands of sick, injured, or displaced wild animals are presented to individuals or organizations who have either a federal or state permit that allows them to care for these animals with the goal of releasing them back to the wild. The purpose of this review is to demonstrate the complexity of considerations rehabilitators and veterinarians face while trying to optimize the welfare of wild animals in need of care and rehabilitation. The process of rehabilitation is inherently stressful for wildlife.
View Article and Find Full Text PDFAntibiotic resistance ABC-Fs (ARE ABC-Fs) are translation factors that provide resistance against clinically important ribosome-targeting antibiotics which are proliferating among pathogens. Here, we combine genetic and structural approaches to determine the regulation of streptococcal ARE ABC-F gene msrD in response to macrolide exposure. We show that binding of cladinose-containing macrolides to the ribosome prompts insertion of the leader peptide MsrDL into a crevice of the ribosomal exit tunnel, which is conserved throughout bacteria and eukaryotes.
View Article and Find Full Text PDFAs antimicrobial resistance threatens our ability to treat common bacterial infections, new antibiotics with limited cross-resistance are urgently needed. In this regard, natural products that target the bacterial ribosome have the potential to be developed into potent drugs through structure-guided design, provided their mechanisms of action are well understood. Here we use inverse toeprinting coupled to next-generation sequencing to show that the aromatic polyketide tetracenomycin X primarily inhibits peptide bond formation between an incoming aminoacyl-tRNA and a terminal Gln-Lys (QK) motif in the nascent polypeptide.
View Article and Find Full Text PDFEnterococci are commensal gut microbes of most land animals. They diversified over hundreds of millions of years adapting to evolving hosts and host diets. Of over 60 known enterococcal species, and uniquely emerged in the antibiotic era among leading causes of multidrug resistant hospital-associated infection.
View Article and Find Full Text PDFPhaeohyphomycosis caused by species represents an important disease of concern for farmed and aquarium-housed fish. The objective of this study was to summarize the clinical findings and diagnosis of infections in aquarium-housed . Clinical records and postmortem pathology reports were reviewed for 15 individuals from 5 public aquaria in the United States and Canada from 2007 to 2015.
View Article and Find Full Text PDFThis report documents cases of fatal pulmonary mycosis caused by entomopathogenic fungi in the genera and (Order Hypocreales) in a loggerhead sea turtle (), a Chinese alligator (), two gopher tortoises (), a Cuvier's dwarf caiman (), a false gharial (), a green sea turtle (), and a Kemp's ridley sea turtle (), and a case of granulomatous coelomitis in a hawksbill sea turtle (). Fungi identified in these cases included , , , , and one case of infection by a novel species. The animals were either housed at zoos or brought into rehabilitation from the wild.
View Article and Find Full Text PDFBackground: This multi-institutional retrospective study evaluated the feasibility and safety of endoscopic sex identification in 467 turtles and tortoises, representing 10 species.
Methods: Medical records of turtles and tortoises that underwent endoscopic sex identification at the University of Georgia, New England Aquarium and Turtle Conservancy were reviewed for presurgical management, anaesthesia, endoscopic equipment and surgical techniques, endoscopic results and complications.
Results: The majority of animals weighed less than 200 g, were fasted and anaesthetised using an injectable combination of ketamine, dexmedetomidine and morphine or hydromorphone, supplemented by local lidocaine at the prefemoral site.
Between 2007 and 2020 at New England Aquarium, Boston, MA, USA, we implanted passive integrated transponder (PIT) tags into 728 fish representing 105 teleost and elasmobranch species to identify animals as individuals. At the time of retrospective data analysis, mean longevity interval (median, range) after tag placement for animals that remained alive (n = 236) was 4.7 years (4.
View Article and Find Full Text PDFFibropapillomatosis (FP), a debilitating, infectious neoplastic disease, is rarely reported in endangered Kemp's ridley sea turtles (). With this study, we describe FP and the associated chelonid alphaherpesvirus 5 (ChHV5) in Kemp's ridley turtles encountered in the United States during 2006-2020. Analysis of 22 case reports of Kemp's ridley turtles with FP revealed that while the disease was mild in most cases, 54.
View Article and Find Full Text PDFObjective: To characterize osteolytic lesions in cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) hospitalized for rehabilitation and describe methods used for the management of such lesions.
Animals: 25 stranded, cold-stunned Kemp's ridley sea turtles hospitalized between 2008 and 2018.
Procedures: Medical records of sea turtles with a diagnosis of osteolytic lesions were reviewed retrospectively to obtain the date of diagnosis, clinical signs, radiographic findings, microbial culture results, hematologic and plasma biochemical data, cytologic and histologic findings, antimicrobial history, time to first negative culture result, treatment duration, and outcome.
Respiratory disease is a common cause of morbidity and mortality in sea turtles, including the Kemp's ridley sea turtle (). Although culture-dependent methods are typically used to characterize microbes associated with pneumonia and to determine treatment, culture-independent methods can provide a deeper understanding of the respiratory microbial communities and lead to a more accurate diagnosis. In this study, we characterized the tracheal lavage microbiome from cold-stunned Kemp's ridley sea turtles at three time points during rehabilitation (intake, rehabilitation, and convalescence) by analyzing the 16S rRNA gene collected from tracheal lavage samples.
View Article and Find Full Text PDFThe process of optimizing the properties of biological molecules is paramount for many industrial and medical applications. Directed evolution is a powerful technique for modifying and improving biomolecules such as proteins or nucleic acids (DNA or RNA). Mimicking the mechanism of natural evolution, one can enhance a desired property by applying a suitable selection pressure and sorting improved variants.
View Article and Find Full Text PDFFree L-tryptophan (L-Trp) stalls ribosomes engaged in the synthesis of TnaC, a leader peptide controlling the expression of the Escherichia coli tryptophanase operon. Despite extensive characterization, the molecular mechanism underlying the recognition and response to L-Trp by the TnaC-ribosome complex remains unknown. Here, we use a combined biochemical and structural approach to characterize a TnaC variant (R23F) with greatly enhanced sensitivity for L-Trp.
View Article and Find Full Text PDFMacrolides and ketolides comprise a family of clinically important antibiotics that inhibit protein synthesis by binding within the exit tunnel of the bacterial ribosome. While these antibiotics are known to interrupt translation at specific sequence motifs, with ketolides predominantly stalling at Arg/Lys-X-Arg/Lys motifs and macrolides displaying a broader specificity, a structural basis for their context-specific action has been lacking. Here, we present structures of ribosomes arrested during the synthesis of an Arg-Leu-Arg sequence by the macrolide erythromycin (ERY) and the ketolide telithromycin (TEL).
View Article and Find Full Text PDFThe pathogenesis of steatitis that infrequently occurs in cold-stunned Kemp’s ridley sea turtles (KRT; ) has been undetermined. The objectives of this study were to investigate the clinical ( = 23) and histologic findings ( = 11) in cold-stunned KRT, and to compare plasma concentrations of α-tocopherol (vitamin E), thiobarbituric acid reactive substances (TBARS), and the TBARS to vitamin E (T/E) ratio (an assessment of oxidative stress) between cold-stunned KRT with clinically and/or histologically confirmed steatitis ( = 10) and free-ranging KRT ( = 9). None of the cold-stunned turtles had clinically detectable steatitis at admission, and the median number of days to diagnosis of steatitis was 71 (range 33–469).
View Article and Find Full Text PDFMany juvenile Kemp's ridley () and loggerhead () turtles strand during fall on the beaches of Cape Cod (MA, USA), with total stranding numbers sometimes exceeding 300 turtles per year. Once rehabilitated, turtles must be released at beaches with appropriate water temperatures, often requiring transportation to southeastern coastal states of the USA. These transportation events (transports) may approach or exceed 24 h in duration.
View Article and Find Full Text PDFBlood was collected from wild captured green and Kemp's ridley turtles off the west coast of Florida, USA. Blood gases and biochemical values were analyzed using a point of care (POC) device in the field. Analytes include pH, partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), oxygen saturation (sO2), lactate, sodium (Na), potassium (K), chloride (Cl), total carbon dioxide (TCO2), anion gap, ionized calcium, glucose, blood urea nitrogen (BUN), creatinine (Crea), hematocrit (Hct), and hemoglobin (Hb).
View Article and Find Full Text PDFFEMS Microbiol Rev
November 2020
Resistance to antimicrobial drugs used to treat bacterial, viral, fungal and parasitic infections is a major health concern requiring a coordinated response across the globe. An important aspect in the fight against antimicrobial resistance is the development of novel drugs that are effective against resistant pathogens. Drug development is a complex trans-disciplinary endeavor, in which structural biology plays a major role by providing detailed functional and mechanistic information on an antimicrobial target and its interactions with small molecule inhibitors.
View Article and Find Full Text PDFAn 11-day-old little blue penguin () died unexpectedly. Prior to hatching, the egg experienced trauma and resultant defects were repaired. The chick hatched without complication and was clinically normal prior to death.
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