Initially, antimicrobial resistance (AMR) stood as a remarkable manifestation of bacterial intelligence, adapting and thriving in the modern scientific landscape of humanity. Its presence, akin to the proliferation of plastics in today’s oceans, didn’t raise significant concerns initially. However, as the reservoir of resistant bacteria burgeoned, scientists began grappling with a pivotal question: Could AMR bacteria not only inhabit but potentially dominate our world, or even forge a new one?
Assistant Professor
Department of Fish Pathology and Health Management, TNJFU, India
Bacteria can be perceived as superorganisms, seamlessly coexisting with us in a manner reminiscent of the diverse life forms on Earth. Inhabiting our gut, they mirror the intricate web of life that surrounds us, persisting even after our demise, nourished by the remnants of our existence. The fascinating intelligence exhibited by these microorganisms prompts contemplation about the hypothetical scenario of a microbial uprising, where these bacteria, residing within us, embark on a transformative battle to supplant our dominance. Envision the intriguing question: What ingenious weaponry might they employ to assert their newfound supremacy?
As the realm of medicine underwent a revolution, the trajectory of sophisticated living evolved in tandem. The breakthrough of the germ theory illuminated the presence of bacteria, setting the stage for a transformative understanding. The revelation of antibiotics emerged as a potent weapon in our arsenal against bacterial adversaries, reshaping the landscape of medical warfare. Evolving medical practices acted as a bulwark, curtailing the spread of diseases, transforming once-incurable ailments into recoverable conditions. Casualties dwindled with the advent of vaccines, reducing the toll of afflictions.
Today, treatments are conveniently accessible with just a tap, ushering in an era of unparalleled medical convenience. Yet, amidst these strides, a palpable absence lingers. Since the inception of modern medicine in the 20th century, marked by the discovery of penicillin, humanity held an optimistic view of antibiotics. Experts lauded the profound role these antimicrobial agents played in treating infectious diseases. However, as we entered the next century, optimism gave way to concern with the emergence of the antibiotic pipeline, signifying the ascent of resistant bacterial strains.
What sets antimicrobial resistance (AMR) apart, causing many eyebrows to raise, is its exceptional nature— a phenomenon challenging the efficacy of once-reliable antibiotics and posing a significant threat to our ability to combat infectious diseases effectively.
The word ‘pandemic’ resonates frequently in our present, raising the question: Could the next pandemic be the insidious rise of Antimicrobial Resistance (AMR)? This imperceptible force is burgeoning beyond conventional limits, prompting reflection on the dual nature of scientific progress. Does science, in its pursuit of knowledge and solutions, bring forth both blessings and challenges, leaving us to grapple with the nuanced consequences of our discoveries?”
NEED FOR AN HOUR
Initially, antimicrobial resistance (AMR) stood as a remarkable manifestation of bacterial intelligence, adapting and thriving in the modern scientific landscape of humanity. Its presence, akin to the proliferation of plastics in today’s oceans, didn’t raise significant concerns initially. However, as the reservoir of resistant bacteria burgeoned, scientists began grappling with a pivotal question: Could AMR bacteria not only inhabit but potentially dominate our world, or even forge a new one?
The gravity of the AMR crisis becomes evident in the intricate web connecting people, animals, and plants. It transcends beyond a mere healthcare issue, extending its ominous influence to threaten crops, farms, and ultimately, the food security of nations. This complex interdependence highlights the multifaceted nature of the AMR challenge. From the perspective of a fish pathologist, the urgency to underscore the significance of shrimp farms becomes imperative. Regrettably, these farms, serving as the primary and widely adopted practice, unwittingly become reservoirs for the global dissemination of this invisible adversary. The implications of AMR extend beyond the realm of health, infiltrating crucial sectors and demanding a holistic approach to safeguard our interconnected world.
RISKS AND CONSEQUENCES OF UNCONTROLLED ANTIBIOTIC USE IN SHRIMP FARMING
Shrimp farming in Asia heavily relies on antibiotics, with approximately 10% of shrimp feed containing antibiotics such as ciprofloxacin, chloramphenicol, erythromycin, co-trimoxazole, and tetracycline. The unregulated access to antibiotics in regions lacking proper oversight results in their indiscriminate use, contributing to antibiotic resistance in both pathogenic and non-pathogenic bacteria. The extensive use of antibiotics in intensive aquaculture has led to the emergence and spread of antibiotic resistance, a serious public health concern. Numerous studies have documented antibiotic resistance in bacteria from shrimp farming, and incomplete antibiotic utilization in veterinary and human consumption contributes to the release of antibiotics into the environment. This, in turn, leads to widespread multiple antibiotic resistance and reduced efficacy in treating diseases caused by resistant pathogens. The rise of antibiotic-resistant bacteria and genes poses a significant threat to public health, as human exposure to antimicrobial resistance can occur through the consumption of aquaculture products. Minimizing total antibiotic usage is crucial to alleviate the selection pressure for antimicrobial resistance.
The issue of antibiotic resistance in human medicine stems from inappropriate or excessive antibiotic use. However, in aquaculture, sub-therapeutic levels of antibiotics in the environment, especially in shrimp ponds, have been identified as the primary source of antibiotics. The long-term prevalence of antibiotic resistance genes (ARGs) in shrimp aquaculture, found in pond water, sediment, and shrimp intestinal tracts, creates conditions favorable for transferring these genes to indigenous or pathogenic microorganisms. This transfer jeopardizes the efficacy of antibiotics used in treating bacterial infections and poses risks to both the aquaculture industry and human health. Research indicates a significant prevalence of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) in seafood, including marine fish, shrimp, and mussels.
Investigations in mariculture farms revealed resistance in Vibrio parahaemolyticus isolates obtained from various seafood. The high resistance levels observed, particularly for methicillin and penicillin, reflect the global challenge of combating antimicrobial resistance in both clinical and environmental settings.
The release of antibiotics into the environment has adverse consequences for the ecological system and human health. Methicillin-resistant Staphylococcus aureus (MRSA) strains, resistant to methicillin and other β-lactam antibiotics, pose significant challenges in treating infections and have been reported worldwide.
SHORT INSIGHTS FROM MY RESEARCH
Here is my never-ending story of AMR. We always thought COVID was a threat but AMR is a close second one. This is about finding the one in the shrimp farms of Tamil Nadu. When I started to analyse the occurrence of this pattern, I got 85% positive samples which had shown resistance against commonly used antibiotics in aquaculture including ampicillin along with cephalothin, aztreonam and erythromycin. This means once the shrimp farmer applies the above-described antibiotics, neither the super organism will not get killed nor will the shrimps get better. To know them in a molecular level, I studied the genome of those resistant isolates.
There Antimicrobial Resistant Genes (ARG) or r-genes are the group of genes responsible for the AMR in the molecular level. Imagine the AMR bacteria as Avengers team. Suppose the Ironman is resistant to penicillin, and he has penicillin resistance genes (beta lactamase resistant genes) in his genome. He will also be very good at sharing his gene by making copies to Captain America and in such a way these two guys will share and spread their resistant genes to the whole group and the group members while fighting for the world will pour their genes in the environment and during this process of busy globetrotting, those genes will mutate randomly and increase their spectra of resistance. This process is simply called as ‘Genetic Jugglery’. Beta lactamase gene (eg – blaTEM, blaSHV etc…) and macrolides (eg- erm C, erm B etc…) are 2 major genes that have shown this universal distribution with extended spectrum of resistance. This study shows positive for the blaTEM gene & ermB gene. This resistance can be linked to the other antibiotics by overuse or improper use of antibiotics in shrimp farms. I studied the shrimp farms of Nagapattinam district. There is a canal running at the rear of these farms where the effluents from the farms are mixing up & people are catching fish from there for food. So, there is a certain possibility of the spread of this invisible AMR soul traveling beyond its limits to create their world. Carrying AMR bacteria in our gut could potentially lead to infection, which is difficult to treat. People may not display any symptoms when colonized, but they might suffer from infections in the future (or) pass on the resistant bacteria in their gut to other people who may become more vulnerable.
CONCLUSION
The escalating use and accessibility of antibiotics have highlighted a concerning trend: the pathogens targeted to prevent harm to humans and animals are developing resistance, diminishing the effectiveness of these crucial tools. Certainly, advanced technology and dedicated scientific research offer promising futuristic solutions to address environmental and health concerns. However, the substantial use of antibiotics can be curtailed by farmers to ensure food safety.
Recent headlines have highlighted the rejection of Indian shrimp exports by the European Union, attributing it to the use of prohibited antibiotics. In this context, upskilling becomes crucial, tapping into the potential of students and newcomers to raise awareness among farmers and readers. Additionally, establishing realistic goals for the proper and judicious use of antibiotics is imperative. Addressing antibiotic resistance requires a multifaceted approach, including responsible antibiotic use in both human and veterinary medicine, enhanced surveillance, development of new antibiotics, and public awareness. Collaboration on a global scale is essential to combat this growing threat and ensure that antibiotics remain effective in treating bacterial infections, safeguarding the well-being of both humans and animals.
References
1. Dhayanath, M., Kurcheti, P.P., Mary, S.J., Paul, T. and Majethia, H., 2019. Prevalence of antimicrobial resistance among Vibrio spp. isolated from the digestive tract of cultured Penaeus vannamei. Journal of Animal Research, 9(5), pp.675-681.
2. Mary, S.J.A.J., Dhayanath, M. and Paul, T., 2019. Prevalence and Characteriztion of Antibiotic Resistance Associated with Escherichia coli Isolated from Cultured Penaeus vannamei from Maharashtra, India. International Journal of Current Microbiology and Applied Sciences, 8(7), pp.1790-1797.
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5. Sudan P, Tyagi A, Dar RA et al (2023) Prevalence and antimicrobial resistance of food safety related Vibrio species in inland saline water shrimp culture farms. Int Microbiol 26, 591–600.
6. Thornber K, Verner‐Jeffreys D, Hinchliffe S, Rahman MM, Bass D, Tyler CR (2020) Evaluating antimicrobial resistance in the global shrimp industry. Rev Aquac 12(2):966-86.
About Abisha Juliet Mary S J
Abisha Juliet Mary is currently serving as an Assistant Professor at the Department of Fish Pathology and Health Management at TNJFU- Dr. MGR Fisheries College and Research Institute, located in Thalainayeru. Her area of expertise lies in Fish Pathology and Health Management. She is actively engaged in an ongoing research project titled “Spatial Distribution of β-Lactam Resistance Genes among Vibrio spp Isolated from Shrimp Farms of Vedaranyam”. This project contributes significantly to the understanding of antimicrobial resistance patterns in aquatic environments and the potential risks they pose to the aquaculture industry.
