Multifunctional carbonized nanogels to treat lethal acute hepatopancreatic necrosis disease
This research paper delves into therapeutic methods for Acute Hepatopancreatic Necrosis Disease (AHPND) in shrimp. It has been published in the esteemed ‘Journalof Nanobiotechnology’ which falls under the internationally renowned‘Nature Publishing Group.’ Remarkably, it boasts an impressive impact factor of 10.435—a rarity in the field of aquaculture.
Within the paper, two significant breakthroughs take center stage:
1. Innovative Carbon Material Synthesis:
Through the combination of two rawmaterials and the application of specialized processing techniques, a multifunctional therapeutic carbon material has been developed. Experimental findings reveal that when shrimp are exposed to high doses of AHPND pathogens and protein toxins, this material effectively curtails bacterial growth and absorbs toxins, resulting in a remarkable threefold increase in survival rates.
2. Comprehensive Evaluationof Antimicrobial Material:
Rigorous investigationsinto the physiological and toxicological effects of this antibacterial material on shrimp have been conducted. From cellular biology and histology to genetics and even gut microbiota analysis, the safety of this therapeutic carbon material has been firmly established. Notably, unlike antibiotics, it maintains gut microbial diversity while acting as a brake during pathogen outbreaks, effectively suppressing harmful bacterial proliferation.
Combining Direct PCR Technology and Capillary Electrophoresis for an Easy-to-Operate and Highly Sensitive Infectious Disease Detection System for Shrimp
Infectious diseases are considered the greatest threat to the modern high-density shrimp aquaculture industry. The specificity, rapidity, and sensitivity of molecular diagnostic methods make them applicable for shrimp detection, allowing preventive measures to be taken before disease outbreaks occur.
This paper explores the use of direct polymerase chain reaction as a convenient method for routine molecular detection of pathogens in infected shrimp. Four different direct PCR reagent brands were tested in this study, revealing that the detection signal of direct PCR in hepatopancreatic tissue was significantly affected. Additionally, portable capillary electrophoresis was employed to enhance sensitivity and specificity, resulting in a pathogen detection limit of 25 copies per PCR reaction. Furthermore, the overall detection time was reduced by more than 58%. This research reveals the combination of direct PCR and capillary electrophoresis holds promise as a valuable tool for on-site examination in shrimp aquaculture, with potential applications in diagnostics, epidemiology, and pathological studies.
Pathogen Challenge Test
In the laboratory, we fed white leg shrimptwo different diets: a commercial diet (serving as the control group) and a
diet enriched with the HerbmedotcinTM Prawn Shield feed additive. After 7 days, we introduced high concentrationsof AHPND pathogenic Vibrio parahaemolyticus into the culture water. We closely monitored the survivalrate of the white leg shrimp during this high-risk challenge period.The statistical experiment results revealed the following: The control groups, when exposed to Vibrio parahaemolyticus, exhibited a 22% survival rate. In contrast, the experimental groups demonstrated an impressive 93% survival rate (as depicted in the figure below). These findings underscore the excellent protective efficacy of the HerbmedotcinTM Prawn Shield feed additive against AHPND.
Furthermore, we individually extracted the gastrointestinal from the experimental group, the control group, and healthy normal shrimp for microbial culture. Additionally, we obtained hepatopancreas tissues for histological examination. Upon comparing the hepatopancreas tissues of normal shrimp, we observed that they exhibited normal characteristics. In the microbial culture, only a small number of vibrios were detected. However, in the control group following the pathogen challenge test, the hepatopancreas tissues displayed signs of infection and damage. The microbial culture also revealed a substantial presence of vibrios. In contrast, the experimental group of shrimp exhibited intact hepatopancreas tissues, and the vibrio count in the microbial culture was even lower than that observed in normal shrimp. These findings suggest that the HerbmedotcinTM Prawn Shield feed additive indeed enhances shrimp resistance against vibrio infections.
Detection Kits for Shrimp Disease
Case: HONEST M.A.NTM Shrimp Disease Detection System—MultiOne PCR Kit Test
Location: Pingtung,Taiwan
Situation:
Ashrimp farmer discovered that shrimp (size: 50 counts per kilograms) in the pond were dying at an alarming rate. Initially, around 20 kilograms of dead shrimp were retrieved from the pond, and subsequently, approximately 6 kilograms of shrimp continued to die every day. Additionally, observations revealed that the shrimp had white flesh, unclear liver and pancreas, empty intestines and stomach, red tails and antennae, and darker spots. In a state of panic, urgent assistance was requested to address the situation
Action & Result:
Given that the HONEST M.A.NTM Shrimp Disease Detection System—MultiOne PCR Kit can simultaneously test for four pathogens, allowing for rapid identification of the disease source, we utilized it for testing. The results indicated a positive detection for WSSV in the shrimp samples.Becausethe shrimp have reached harvestable size and are experiencing a severe large-scale mortality event, we recommend harvesting promptly to mitigate further losses for the shrimp farmers.
The MultiOne PCR kit is a rapid, accurate, and efficient shrimp disease testing system that can simultaneously detect four different pathogens.It enables quick and effective on-site testing and assessment.
Key features include:
- Time and Cost Savings: By streamlining routine testing, it makes conventional inspections more feasible.
- Enhanced Disease Monitoring and Control: It improves disease surveillance and control efficiency in aquaculture.
This system is a valuable tool for shrimp farmers and aquaculture professionals, aiding in timely disease detection and management.
Case: HONEST M.A.NTM Shrimp Disease Detection System—HLVD Detection Kit Test
Location: VietnamSituation:
The Translucent Post-Larvae Disease (TPD), a newly recognized peril to shrimp, primarily impacts larvae by affecting their hepatopancreatic ducts and midgut epithelium. This condition leads to a staggering mortality rate exceeding 90% within 24-48 hours after symptoms emerge, hence the name “Highly Lethal Vibrio Disease” (HLVD). Back in 2020, numerous white shrimp hatcheries situated along the Chinese coastline observed widespread HLVD outbreaks in their larvae populations.
At a white shrimp farm located in the southern region of Vietnam, the owner noted symptoms of enteritis and a whitening of the hepatopancreas in the shrimp, merely a month after they were introduced. This was soon followed by a series of deaths among the stock. Suspecting an infection of Acute Hepatopancreatic Necrosis Disease (AHPND), the owner sought our expertise for confirmatory diagnostic tests.
Action & Result:
After conducting tests using the HLVD detection kit, it was revealed that the shrimp did not harbor AHPND; rather, they were infected with a strain of Vibrio bacteria responsible for HLVD. This discovery substantiates the quiet
proliferation of the Translucent Post-Larvae Disease across global shrimp cultivation areas.
We advise suppliers of shrimp seedlings to carry out appropriate disease screenings prior to distribution, and for farmers to do the same before stocking their ponds. It is prudent to test not only for prevalent diseases like EHP, AHPND, and WSSV but also for HLVD to avert potential losses.
Case: HONEST M.A.NTM Shrimp Disease Detection System—QCOne PCR Kit Test
Location: Pingtung, Taiwan
Situation:
A shrimp farmer called for assistance, reporting that some of the shrimp in the nursery nets were excreting white feces, although no abnormalities were visible from the shrimp’s appearance. The white feces could be caused by Vibrio bacteria, microsporidian parasites, or other complex infections. To determine the cause of the white feces and the severity of the infection, samples have been sent for analysis.
Action & Result:
Utilizing the QCOne PCR kit, we determined the main cause of the disease outbreak and assessed the infection level. The analysis identified an EHP microsporidian infection in the shrimp, with pathogen levels around 5X103,signifying a moderate infection. Given that the shrimp were not yet of marketable size, we opted to proceed with their cultivation.
After about three weeks of treatment and adjustment, there was an improvement in the white feces condition. However, significant size variation among the shrimp was observed, prompting a decision to monitor the progression of the EHP infection. Further testing indicated that the pathogen levels had risen to approximately 5X104, a significant increase from the initial results. The worsening condition was likely due to the cold winter season, which resulted in decreased feeding, stunted growth, and a notable size variation within the shrimp population, all of which aggravated the EHP infection. In response, the farmer opted for an early harvest, followed by a comprehensive cleaning and disinfection of the pond to set the stage for a healthier subsequent crop cycle.
The red line represents the Negative Control Group (Neg.). Inthe middle, there is a peak corresponding to the quantitative standard of 104.
The blue line represents the Positive Control Group (Pos.). Inthe middle, there are two distinct peaks: the one on the right corresponds to the quantitative standard, and the one on the left represents the positive control signal.
The green line corresponds to the first sampling: It exhibitstwo signals, indicating a positive sample. The signal on the left is approximately half the intensity of the one on the right, suggesting a pathogen level of approximately 5x103.
The yellow line corresponds to the second sampling: The signalon the left is approximately twice the intensity of the one on the right, indicating a pathogen level of approximately 5x104.The QCOne PCR kit’s semi-quantitative nature makes it ideal for assessments that demand precise quantification, providing a reliable foundation for critical decision-making.
In aquaculture, the accurate disease detection offered by the QCOne PCR kit enhances the understanding of on-site conditions, supporting informed decision-making and appropriate operational management.Shrimp Feed Additives
