博士 / 國立中興大學 / 微生物暨公共衛生學研究所 / 106 / Sea turtles are important components of ocean ecosystems; however, their numbers are in decline in many regions. Marine turtles are exposed to a number of threats, including human catch, unintended catch, boat collisions, marine debris, coastal development, environmental pollutants, and infectious diseases. Among many diseases, fibropapillomatosis (FP) is considered to be of major importance threatening sea turtle surviving. Centers for sea turtle rehabilitation play an important role in conservation of sea turtle populations, and veterinary care plays an influential role in sea turtle rehabilitation. Physiological characteristics, hematological and plasma biochemistry profiles, are useful references for clinical management in animals, especially when animals are during the convalescence period. Fibropapillomatosis (FP), a debilitating tumor disease of sea turtles, was first identified in green turtles (Chelonia mydas) in Florida in 1938. In recent decades, FP has been observed globally and is an emerging panzootic disease in sea turtles. However, few reports of FP in Asia have been published up to date. The aims of this study were :1) to establish a summarized survival prediction index for use in sea turtle rescue; 2) to compare hematology and plasma biochemistry values of green sea turtles with and without fibropapillomatosis; 3) to characterize molecular epidemiology of the chelonid herpesvirus 5 (ChHV5) from Taiwan green sea turtles with fibropapillomatosis. The results indicated that significantly negative correlation was found between buoyancy disorders (BD) and sea turtle surviving (p < 0.05). Furthermore, non-surviving sea turtles had significantly higher levels of aspartate aminotranspherase (AST), creatinine kinase (CK), creatinine and uric acid (UA) than surviving sea turtles (all p < 0.05). After further analysis by multiple logistic regression model, only factors of BD, creatinine and UA play substantial roles to predict sea turtle survival and were included in the mathematical equation for calculating a summarized health index (SHI) for each individual. Through evaluation by receiver operating characteristic (ROC) curve, the result indicated that the area under curve was 0.920 ±0.037, and a cut-off SHI value of 2.5244 showed 80.0% sensitivity and 86.7% specificity in predicting sea turtle survival. Therefore, the developed SHI could be a useful index to evaluate health status of sea turtles and to improve veterinary care at rehabilitation facilities. Significantly higher value of plasma alanine aminotransferase was identified for the turtles with FP, when compared to the turtles without FP. Significantly lower iron level was detected in the turtles with FP, when compared to the turtles without FP. Elevated value of ALT and lower iron level in turtles with FP may result from spirorchiid infection. Using FP tumors for molecular studies, ChHV5 was successfully detected by PCR in FP tumor lesions of green turtles. The sequences were found to be consistent with those of tumor-inducing viruses shown to affect sea turtles in the other parts of the world. ChHV5 RNA from the FP tissues was further detected by RT-PCR, indicating active replication of the viruses inside FP tumors. In addition to show molecular evidence of ChHV5 in FP, epidermal intranuclear inclusions were further identified in tumor lesions upon histopathological examination. This result suggests that ChHV5 should be in a transcriptionally active (i.e., non-latent) state in FP tumors of affected green turtles. The phylogenetic tree revealed that ChHV5 from the green turtles in Taiwan were closest to the ChHV5 from Hawaii, Puerto Rico, and Sao Tome. For conservation of endangered sea turtles, ChHV5 should be considered an emerging virus, which threatens sea turtles in marine waters in Asia.
| Identifer | oai:union.ndltd.org:TW/106NCHU5773003 |
| Date | January 2017 |
| Creators | Tsung-Hsien Li, 李宗賢 |
| Contributors | 張照勤 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 95 |
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