Development of reference intervals for serum biochemistry and haematology of juvenile green sea turtles (Chelonia mydas) in a Thai rehabilitation centre.

No reference intervals for serum biochemistry and haematology of sea turtles in Thailand exists to assist veterinarians who are responsible for sea turtle health management and treatment. This study determined serum biochemistry and basic haematology of healthy juvenile green sea turtles (n = 92) in captivity in Thailand following the American Society for Veterinary Clinical Pathology (ASVCP), Quality Assurance and Laboratory Standards Committee (QALS) guidelines for the determination of reference intervals in veterinary species. Biochemistry tests, including blood urea nitrogen, creatinine, uric acid, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were analysed using an IDEXX VetTest Chemistry Analyzer. Haematology parameters were measured manually using a microhaematocrit for packed cell volume (PCV), Neubauer counting chamber for red blood cell count and cyanmethemoglobin method for haemoglobin concentration. mean corpuscular volume and mean corpuscular haemoglobin concentration were calculated using the PCV, red blood cell count and haemoglobin. Turtles in this study were found to have higher mean values for PCV (28.70%), haemoglobin (92.13 g/L), mean corpuscular haemoglobin concentration (327.03 g/L), uric acid (247.15 µmol/L), alanine aminotransferase (16.53 IU/L), aspartate aminotransferase (209.44 IU/L), and alkaline phosphatase (245.08 IU/L) compared to sea turtles in Brazil. The reference intervals established using high numbers of healthy turtles in this study will assist veterinarians with diagnostic and treatment decisions when evaluating laboratory results for juvenile green sea turtles.

Non-permissive C6/36 cell culture for the Australian isolate of Macrobrachium rosenbergii nodavirus.

Macrobrachium rosenbergii nodavirus (MrNV) that causes white tail disease (WTD) is an emerging disease that contributes to serious production losses in Macrobrachium hatcheries worldwide. Mosquito cell lines (C6/36) have been reported to support the growth of MrNV and used to observe the cytopathic effects (CPE) in infected cells. This study determined the susceptibility of C6/36 mosquito cells to the Australian isolate of MrNV in order to use fewer animals in further investigations. Different staining methods were used to observe MrNV viral activity in C6/36 cells. Typical cytopathic effects such as vacuolation and viral inclusion bodies were observed in infected C6/36 cells with H&E and Giemsa staining. With acridine orange, it was easier to detect presumptive MrNV messenger ribonucleic acid in the infected cells. Using neutral red staining to measure mitochondrial activity showed light absorption of infected cells maximized at day 4 (O.D. = 0.6) but was significantly lower (chi-square = 41.265, df = 1, P < 0.05) than control groups (O.D. = 2) which maximized at day 12. Using trypan blue staining to count the number of cells with disrupted cell membranes, the maximum number of presumptively dead cells at day 8 (4 × 10(5)  cells) in infected treatments was higher than the control treatment at day 10 (1.8 × 10(5)  cells). However, TaqMan real-time PCR did not confirm the replication of MrNV in the cells over 14 days. The mean viral copies and mean cycle times of positive samples were stable at 2.07 × 10(4) and 24.12, respectively. Limited evidence of viral replication was observed during four serial passages. This study determined the mortality of the C6/36 cell line to the Australian isolate of MrNV but suggests limited patent replication was occurring. Trying different cell lines or adapting the virus to the C6/36 cells may be necessary to successfully replicate Australian MrNV in cell lines.