Seminar on Microorganisms and Antibiotic Resistance

Introduction

• Good afternoon and welcome to the hybrid seminar at LNB.
• Technical details: Questions at the end; online audience to submit in Q&A.
• Overview of the MRC Laboratory of Molecular Biology (LMB):
  • World-leading research institute on biological processes.
  • Focus on problems related to human health.

Speaker Introduction: Tanmay Bharat

• Education Background:
  • BSc in Chemistry (University of Delhi)
  • BA in Biological Sciences (University of Oxford)
  • PhD from the European Molecular Biology Laboratory (Heidelberg, Germany)
  • Postdoctoral training at LMBE, then Group Leader at University of Oxford.
• Current Position: Program Leader at LMB since 2022.
• Talk Focus: Insights on how bacteria evade antibiotic treatment and implications for new treatment strategies.

Microorganisms: Bacteria and Archaea

• Definition and comparison between eukaryotes (humans, plants) and prokaryotes (bacteria).
• Size: Microbial cells (1-10 microns) vs. human cells (100 microns).
• Evolution: Microorganisms were the first organisms on Earth, approximately 5 billion years ago.
• Estimated presence of over 1 trillion microbial species and 10^30 microbial cells on Earth.

Habitats of Microorganisms

• Microbes found in diverse environments:
  • Hot springs (e.g., Yellowstone National Park)
  • Cold conditions (e.g., Antarctica)
  • Hyper saline environments (e.g., Dead Sea)
  • Nuclear contaminated sites (e.g., Chernobyl)
• Microorganisms in the human body:
  • Over 100 trillion microbes in an adult human (oral microbiome, skin, gut, urogenital tract).
  • Most are beneficial, but some can cause disease.

Bacterial Infections and Diseases

• Types of bacterial infections:
  • Meningitis (Neisseria meningitis, Haemophilus influenzae)
  • Ear, skin infections (Staphylococcus aureus)
  • Lung infections (Streptococcus pneumoniae)
  • Urinary tract infections (E. coli)
• Symptoms vary by infection site (fever, chills, pain).

Antibiotics: Discovery and Challenges

• Discovery of penicillin by Alexander Fleming in the 20th century.
• Importance of antibiotics in treating bacterial infections.
• Antibiotic-resistant bacteria:
  • World Health Organization (2017) list of antibiotic-resistant pathogens (e.g., Pseudomonas aeruginosa, Staphylococcus aureus).

Mechanisms of Antibiotic Resistance

• Biofilm formation:
  • Multicellular aggregates that protect bacteria from antibiotics.
  • Over 75% of human infections involve biofilm formation.
  • Biofilms can form on human tissues and medical devices.
• Characteristics of Biofilms:
  • Initial attachment, extracellular matrix secretion, chronic infection.
  • Loss of motility and change in metabolism.

Research Focus: Pseudomonas aeruginosa

• Major human pathogen and significant antibiotic-resistant killer.
• Use of electron microscopy to study biofilm structures.
• Master adhesive protein:
  • Role in biofilm formation and attachment.
  • Use of nanobodies to enhance antibiotic efficacy against biofilms.

Treatment Approaches

• Phage therapy:
  • Use of bacteriophages that can evolve and kill bacteria.
• New antibiotics:
  • Discovery of compounds like darobactin and tyxobactin from environmental samples.
• Collaboration needed between fundamental researchers and clinicians for practical applications.

Conclusion

• Call for ongoing research and interaction with policymakers to address antibiotic resistance.
• Acknowledgments and thanks to collaborators and audience.

Questions and Answers

• Can all bacteria form biofilms?
  • Likely yes, under certain conditions.
• Are biofilms purely physical barriers?
  • Physical and biochemical modes of action.
• Composition of biofilm?
  • Made of proteins, polysaccharides, and DNA; composition not fully known.
• Microorganisms in the human body:
  • Gained after birth, not present at birth.