Isolation and characterization of porcine parvovirus in Vietnam
Bibliographic record
Abstract
Background and Aim: No study has successfully isolated parvovirus in Vietnam. This study aimed to isolate and characterize parvovirus strains indigenous in Vietnam for vaccine development against porcine parvovirus (PPV). Materials and Methods: We collected serum and stillbirth samples from six provinces in Vietnam, and PPV-positive samples were identified using a polymerase chain reaction. Parvovirus isolation was attempted using the PK-15 cells maintained in a minimum essential medium supplemented with 5% fetal bovine serum and 1% antibiotics (Penicillin-streptomycin). The cells were incubated at 37°C with 5% CO2. Virulence experiments were conducted on white primiparous sows to evaluate the virulence of the PPV strain through hemagglutination inhibition (HI) titers and fetus lesions. Results: We analyzed 360 serum and 32 stillbirth (liver and lungs) samples, revealing that 32/392 (8.2% ) of them were PPV-positive, all belonging to PPV1. Thirty-two PPV-positive samples were successfully isolated, with 100% identity as VP2 sequences. The phylogenetic tree revealed a close relationship with the Kresse strain (isolated from Canada in 1996) and the PPV1-0225-L-SD strain (isolated from China in 2022). Two PPV isolates (VC5 from Dongnai and TX7 from Thanhhoa) that exhibited high 50% tissue culture infectious dose titers were selected for the virulence experiment. On day 21, after injection, the HI antibody titers ranged from 10log2 to 12log2. On day 90, 71%–80% of fetuses were mummified. Conclusion: This study showed that the PPV infection rate in Vietnam was 8.2%. Thirty-two isolates belonged to PPV1. Two PPV strains, VC5 and TX7, were determined to be highly virulent by the results of HI titers after injection into gilts. VC5 and TX7 were determined to be good candidates for further research on PPV vaccines. Keywords: isolation, phylogenetic tree, porcine parvovirus, sow, virulence.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".