Surreal illustration of antimicrobial resistance in shrimp.

Shrimp SOS: Unmasking Antimicrobial Resistance to Save Your Seafood Supper

Theo Raines in Health & Wellness November 2025 • 4 min read.

"A deep dive into the threats facing Pacific white shrimp and what it means for your plate"

Imagine biting into a succulent shrimp, only to realize that what you’re eating is a product of a system battling a silent enemy: antimicrobial resistance. Acute hepatopancreatic necrosis disease (AHPND), initially known as early mortality syndrome (EMS), has been wreaking havoc on shrimp farms since 2011, causing massive economic losses.

Vibrio parahaemolyticus, the bacteria behind AHPND, carries Photorhabdus insect-related (Pir) toxins and is becoming increasingly resistant to antimicrobials. This isn't just a problem for shrimp farmers; it's a growing concern for public health. Antimicrobial resistance (AMR) not only complicates animal treatment but also raises serious questions about the safety of our food supply and environment.

A recent study investigated antimicrobial resistance profiles in Vibrio parahaemolyticus isolates from Pacific white shrimp and pond water in Thailand. The goal was to understand better the spread and impact of AMR in shrimp farming, focusing on quinolone resistance and the presence of the pirAB-like gene. This research highlights the urgent need to monitor and manage antimicrobial use in aquaculture to protect both the industry and public health.

What Does Antimicrobial Resistance Mean for Your Shrimp Dinner?

Surreal illustration of antimicrobial resistance in shrimp.

The study, conducted across seven provinces in Thailand, examined 66 isolates of V. parahaemolyticus from Pacific white shrimp and their pond water. Researchers used disc diffusion assays to assess the bacteria's resistance to common antimicrobials. Worryingly, a high percentage of isolates showed resistance to ampicillin (98.48%), while lower percentages were resistant to doxycycline (3.03%), oxytetracycline (4.55%), erythromycin (6.06%), florfenicol (1.52%), and trimethoprim/sulfamethoxazole (1.52%).

Quinolones, a class of antimicrobials widely used in both humans and animals, are of particular concern. While the isolates in the study were not fully resistant to quinolone agents like ciprofloxacin, enrofloxacin, norfloxacin, and ofloxacin, some showed intermediate susceptibility. This prompted further investigation into plasmid-mediated quinolone resistance (PMQR) genes.

PMQR Genes: Nine PMQR genes were screened to understand better the mechanisms of quinolone resistance. Only the qnrVC quinolone-resistant gene was found in one multidrug-resistant (MDR) isolate collected from pond water.
The PirAB-like Gene: A significant 39.39% of all isolates carried the pirAB-like gene, responsible for causing acute hepatopancreatic necrosis disease in shrimp. This gene was found exclusively in shrimp samples, not in the water.
GyrA Subtyping: By analyzing the gyrA sequence, researchers classified the isolates into five types. The pirAB-like virulent gene was present in three different types, while the MDR isolates belonged to a single type.

These findings emphasize that even low antimicrobial resistance rates can pose a risk. The presence of MDR isolates and their ability to acquire plasmid resistance genes suggests a potential for AMR dissemination in the environment. Constant vigilance and responsible antimicrobial use are critical to mitigating this risk.

Protecting Our Plates: The Future of Shrimp Farming

The study's findings serve as a wake-up call for the aquaculture industry and consumers alike. While V. parahaemolyticus in this study presented low antimicrobial resistance rates, the few isolates that presented MDR profiles and their capabilities to acquire a plasmid resistant gene indicate the risk of AMR dissemination in the environment. By implementing responsible antimicrobial practices and maintaining rigorous monitoring programs, we can safeguard the health of our shrimp and ensure a safer, more sustainable food supply for the future.

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This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.anres.2018.10.010, Alternate LINK

Title: Antimicrobial Resistance And Pirab-Like Profiles Of Vibrio Parahaemolyticus In Pacific White Shrimp

Subject: General Agricultural and Biological Sciences

Journal: Agriculture and Natural Resources

Publisher: Kasetsart University and Development Institute

Authors: Chea Rortana, Worawidh Wajjwalku, Visanu Boonyawiwat, Charuwan Hrianpreecha, Sukanya Thongratsakul, Patamabhorn Amavisit

Published: 2018-08-01

Everything You Need To Know

What does antimicrobial resistance in shrimp farming really mean for the shrimp on my plate?

Antimicrobial resistance in shrimp farming means that bacteria like Vibrio parahaemolyticus, which causes acute hepatopancreatic necrosis disease (AHPND), become less susceptible to drugs designed to kill them. While the study showed generally low resistance, the presence of multidrug-resistant (MDR) isolates and the potential for bacteria to acquire plasmid resistance genes means that diseases like AHPND could become harder to treat, posing risks to shrimp farming and potentially affecting the safety of shrimp intended for consumption.

Can you explain what acute hepatopancreatic necrosis disease (AHPND) is and why it's a problem for shrimp?

Acute hepatopancreatic necrosis disease (AHPND), previously known as early mortality syndrome (EMS), is a disease affecting shrimp, primarily caused by Vibrio parahaemolyticus carrying Photorhabdus insect-related (Pir) toxins. This disease leads to significant economic losses in shrimp farming due to high mortality rates. The presence of the pirAB-like gene in V. parahaemolyticus isolates indicates the potential for causing AHPND in shrimp populations, as highlighted by its prevalence in shrimp samples within the study.

Why is quinolone resistance in Vibrio parahaemolyticus such a big deal, and what does the qnrVC gene have to do with it?

Quinolone resistance in Vibrio parahaemolyticus is concerning because quinolones are important antimicrobials used in both humans and animals. Although the study found that the isolates were not fully resistant to quinolones like ciprofloxacin and enrofloxacin, the presence of the qnrVC quinolone-resistant gene in some isolates suggests a potential for resistance to increase over time. The detection of plasmid-mediated quinolone resistance (PMQR) genes indicates a mechanism by which resistance can spread among bacteria, further complicating treatment options.

What does it mean when Vibrio parahaemolyticus isolates are labeled as multidrug-resistant (MDR)?

The presence of multidrug-resistant (MDR) isolates of Vibrio parahaemolyticus indicates that these bacteria are resistant to multiple antimicrobials. In the study, some isolates showed resistance to ampicillin, doxycycline, oxytetracycline and other antimicrobials. The ability of these MDR isolates to acquire plasmid resistance genes means that antimicrobial resistance (AMR) can spread within bacterial populations, making infections more difficult to treat and posing a significant threat to both aquaculture and public health.

The study mentions that even low antimicrobial resistance rates are concerning. Why is this the case, and what steps can be taken to reduce the risk?

The study suggests that even low rates of antimicrobial resistance can pose a risk due to the potential for resistance to spread. The detection of plasmid-mediated quinolone resistance (PMQR) genes and multidrug-resistant (MDR) isolates highlights this risk. By implementing responsible antimicrobial practices, maintaining rigorous monitoring programs, and understanding the mechanisms of resistance, the aquaculture industry and public health officials can work to mitigate the risks of AMR and ensure a safer food supply.