Characterization of the Virulency of Vibrio spp. in Giant Tiger Shrimp (Penaeus monodon) from Peninsular Malaysia
Bibliographic record
Abstract
Nowadays, bacterial diseases caused by Vibrio spp. pose a significant obstacle to aquaculture growth, affecting socioeconomic development. The presence of pathogenic Vibrio spp. are gaining attention due to widespread mortality in fish and shellfish worldwide. This study investigates the distribution of virulence genes and their pathogenicity by experimentally infecting a healthy group of cultured shrimp, specifically Penaeus monodon. A total of 225 Vibrio spp. isolated from 210 cultured shrimp from various geographical regions in Peninsular Malaysia were examined, resulting in 13 Vibrio spp. being identified and characterized. According to virulence gene assessment, only eight of the 11 virulence genes were detected in the isolates, including chiA (89%), flaC (74%), tlh (72%), toxR (70%), luxR (40%), pirA (11%), pirB (11%), and hlyA (0.4%). Other virulence genes, such as tdh, trh, and ctxA, were not found in any of the isolates (0%). Then, three Vibrio isolates, including V. parahaemolyticus S12-3, V. campbellii S10-4, and V. rotiferianus S24-4, were selected for pathogenicity test based on highest number of virulence genes in each species. These species were subjected to immersion challenge test against postlarvae (PL) P. monodon approximately PL-20 with three different concentrations of 1 × 106, 1 × 107, and 1 × 108 CFU/mL. The V. parahaemolyticus S12-3 was determined to have lethal concentration 50 (LC50) 1 × 105 CFU/mL after 168 hr of exposure. The immersion challenge test resulted in a pale hepatopancreas and empty guts in P. monodon. Histopathological examination showed sloughing of epithelial cells in the hepatopancreatic tubule, hemocytic infiltration, massive vacuolation, and loss of hepatopancreatic tubule structure. Overall, the study demonstrated the virulence and pathogenicity of V. parahaemolyticus S12-3 toward P. monodon, which could be associated with its virulence properties. Furthermore, the current findings will be useful in developing microbiological risk assessments for shrimp farming and aquaculture management.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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 source (direct Gemma or distilled Codex), 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".