One Health Approach to Resistance

One Health & AMR Intro - AMR's Triple Threat

• One Health: Interconnected health of humans, animals, and the environment. Essential for AMR control.
• AMR's Triple Threat:
  • Humans: ↑ infections, treatment failures, mortality, healthcare costs.
  • Animals: ↓ productivity, animal welfare; potential for zoonotic spread of resistant pathogens.
  • Environment: Acts as a reservoir and dissemination route for resistant bacteria and antibiotic resistance genes.

⭐ The WHO has declared AMR as one of the top 10 global public health threats facing humanity.

Human Sector AMR - Hospital Hotbeds

• Hospitals: Key AMR epicenters due to:

  • High density of vulnerable, often immunocompromised, patients.
  • Intensive antimicrobial use, creating strong selection pressure.
  • Frequent invasive procedures & medical devices (e.g., catheters, ventilators).

• Major Drivers of AMR in Hospitals:

  • Suboptimal Infection Prevention & Control (IPC) practices (e.g., hand hygiene lapses, inadequate environmental sanitation).
  • Over-prescription, incorrect dosage, or inappropriate duration of antibiotics.
  • Presence and transmission of multidrug-resistant organisms (MDROs).
  • Biofilm formation on indwelling medical devices.

• Common Hospital-Acquired MDROs: MRSA (Methicillin-resistant Staphylococcus aureus), VRE (Vancomycin-resistant Enterococci), ESBL-producing Enterobacteriaceae (e.g., E. coli, Klebsiella pneumoniae), CRE (Carbapenem-resistant Enterobacteriaceae), MDR-Acinetobacter baumannii, MDR-Pseudomonas aeruginosa.

⭐ Carbapenem-resistant Enterobacteriaceae (CRE) infections are a critical concern, associated with high mortality rates (often >50%) and limited therapeutic options.

• Control Strategies: Robust Antimicrobial Stewardship Programs (ASP) and strict adherence to IPC measures are paramount for containment.

Animal Sector AMR - Farm-to-Fork Peril

• Livestock Antibiotic Use:
  • Growth promotion (historical/illicit), prophylaxis, therapy.
  • Leads to selection pressure for resistant strains.
• Transmission Pathways:
  • Direct contact: Animal-to-human (farmers, vets).
  • Foodborne: Contaminated meat, dairy, eggs.
  • Environmental: Manure → soil/water → crops.
• Key Resistant Zoonotic Pathogens:
  • Salmonella spp., Campylobacter spp.
  • ESBL-E. coli, LA-MRSA (Livestock-Associated MRSA).

⭐ Colistin resistance (e.g., via mcr-1 gene) in E. coli from food animals is a major global concern due to its role as a last-resort antibiotic.

Environmental AMR - Silent Spreaders

• Major Contamination Sources:
  • Untreated/poorly treated wastewater (hospitals, communities, pharmaceutical manufacturing).
  • Agricultural runoff (livestock manure, aquaculture discharge).
• Dissemination Pathways:
  • Water bodies (rivers, lakes, groundwater) → drinking water, irrigation.
  • Soil → crop contamination.
  • Wildlife acting as vectors.
• Key Drivers & Components:
  • Sub-inhibitory antibiotic concentrations select for resistant strains.
  • Presence of resistant bacteria & Antibiotic Resistance Genes (ARGs).
  • Horizontal Gene Transfer (HGT) via Mobile Genetic Elements (MGEs) like plasmids.

⭐ Wastewater treatment plants (WWTPs), especially those receiving hospital or pharmaceutical effluent, are significant hotspots for the selection and dissemination of ARGs into aquatic environments globally, including India.

One Health Interventions - India's AMR Battleplan

India's National Action Plan on AMR (NAP-AMR) adopts a One Health approach, integrating human, animal, and environmental sectors. Key interventions focus on strengthening surveillance, antimicrobial stewardship (AMS), infection prevention & control (IPC), and regulating antibiotic use in livestock and agriculture.

⭐ NAP-AMR was launched in 2017 to combat AMR across India.

High‑Yield Points - ⚡ Biggest Takeaways

• One Health links human, animal, and environmental health to combat Antimicrobial Resistance (AMR).
• It demands a collaborative, multisectoral approach (human, veterinary, environmental).
• Antimicrobial overuse in humans, agriculture, and environmental contamination are key drivers.
• AMR spreads via the food chain, direct contact, and contaminated environments.
• Integrated surveillance and antimicrobial stewardship across sectors are vital interventions.
• The WHO's Global Action Plan (GAP) on AMR champions this unified strategy.