Resumen de Diagnosis and management of Enterococcus spp infections during rehabilitation of cold-stunned Kemp's ridley turtles (Lepidochelys kempii): 50 cases (2006–2012)
Objective—To evaluate clinical data for cold-stunned Kemp's ridley turtles (Lepidochelys kempii) with Enterococcus spp infections during rehabilitation.
Design—Retrospective case series.
Animals—50 stranded cold-stunned Kemp's ridley turtles hospitalized between 2006 and 2012.
Procedures—Medical records for turtles from which Enterococcus spp were isolated were reviewed retrospectively, and clinical data, including morphometric data, body temperature at admission, physical examination findings, antimicrobial medication history, history of medications administered IV, environmental data, day of diagnosis, clinical signs at diagnosis, microbiological testing results, sources of positive culture results, hematologic and plasma biochemical data, cytologic and histopathologic results, radiographic findings, antimicrobial treatments, time to first negative culture result, treatment duration, results of subsequent cultures, and case outcome, were collated and analyzed.
Results—Enterococcus spp were isolated from bacteriologic cultures of blood, bone, joint, and respiratory tract samples and a skin lesion, with supporting evidence of infection provided by histopathologic, cytologic, and radiographic data. Positive culture results were associated with clinical problems such as lethargy, anorexia, and lameness. Most (34/43 [79%]) turtles for which an antemortem diagnosis was made survived with treatment and were released into the wild.
Conclusions and Clinical Relevance—Cold-stunned Kemp's ridley turtles may be affected by serious Enterococcus spp infections during rehabilitation. Recognition and treatment of these infections are important for successful rehabilitation.
Kemp's ridley turtles (Lepidochelys kempii) are native to the United States and Mexico and are the world's most endangered species of marine turtle.1 Adults of this species generally live in the Gulf of Mexico, but juveniles often range along the northeastern coast of the United States during the summer.2 If juveniles fail to migrate to warmer waters in autumn, they are exposed to increasingly cold water temperatures and may become cold stunned. Cold-stunning events have been reported for sea turtles from many temperate localities in the United States and Europe, most often occurring at water temperatures less than approximately 15°C (59°F).3–8 Data from these events indicate that 35% to 85% of cold-stunned turtles are already dead when found stranded on beaches.6,7,9 The reasons for these variable mortality rates have not been determined, but mortality rate is likely affected by the duration and degree of hypothermia, presence of preexisting illness, fitness of the population, species, and other factors.
Among those cold-stunned sea turtles that are hospitalized after being found alive, overall successful rehabilitation and release rates of approximately 60% to 70% have been reported.7,8 Most deaths during hospitalization occur during the first few days because of physiologic derangements secondary to hypothermia.8,10,11 Far fewer deaths occur after the first few days of hospitalization. For example, 1 report8 described an 88% success rate for rehabilitation of cold-stunned sea turtles that survived the first 3 days of hospitalization. Morbidity and death of cold-stunned sea turtles after the first week of hospitalization are most commonly due to secondary pathological conditions such as bacterial and fungal pneumonia, chronic renal failure, osteomyelitis, sepsis, and, in the authors’ experience, mycobacteriosis.8,12,13 In Massachusetts, a coordinated rescue-and-rehabilitation program for cold-stunned sea turtles has been in operation for approximately 20 years. Volunteers and staff of the Massachusetts Audubon Society patrol beaches of Cape Cod from October through January to recover stranded turtles, which are then transported to the New England Aquarium for medical care. Details of the triage and medical management of cold-stunned turtles at the New England Aquarium have been published.8 Briefly, turtles are gradually warmed over several days to a body temperature of 24° to 25°C (75° to 77°F) and treated for dehydration, metabolic derangements, cardiorespiratory depression, and concurrent pathological conditions.8 Assessment of health is obtained over time by serial examinations, observation, and a variety of diagnostic tests. Turtles remain in rehabilitation until they can be released into warmer waters, which is often 6 to 8 months after stranding, depending on geographic location. In some instances, turtles are transferred to secondary care facilities to complete rehabilitation.
In general, most serious bacterial infections of reptiles, including sea turtles, are caused by gram-negative aerobic organisms, which are normal flora of the reptilian oral cavity, skin, and digestive system and the marine environment.8,14 However, in recent years, infections caused by gram-positive bacteria of the genus Enterococcus have been increasingly recognized during rehabilitation of cold-stunned Kemp's ridley turtles, and Enterococcus faecalis is now the most commonly cultured bacteria in cases of septicemia and osteomyelitis in sea turtles at the New England Aquarium. Enterococcus spp are gram-positive bacterial cocci that are normally found in the gastrointestinal tract of many vertebrate species and in the environment. They can cause serious infections in humans, other mammals, and birds and are a common cause of nosocomial infections.15–17 Enterococcus spp have been cultured from the feces, skin, and cloaca of healthy reptiles.18–20 However, reports21–24 of Enterococcus spp infections in reptiles are limited to a few case reports in individual animals. The purpose of the study reported here was to evaluate methods used for diagnosis and medical management of infections caused by Enterococcus spp in hospitalized Kemp's ridley turtles.
