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Hindu

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Context

• Researchers at Columbia University have found that K. pneumoniae bacteria, when infected by bacteriophages, use reverse transcriptase to create a specific protein named Neo.
• This protein can halt bacterial cell replication, effectively stopping the infection.

Details

The Role of Reverse Transcriptase in Diagnostics and Research

• Significance During COVID-19: Reverse transcriptase became crucial in detecting SARS-CoV-2, aiding in rapid and accurate testing.
• Historical Discovery: Independently discovered by researchers Howard Temin and David Baltimore in 1970, reverse transcriptase showed that RNA could reverse-transcribe into DNA, challenging the Central Dogma of molecular biology.
• Impact: Revolutionized molecular biology research and diagnostics by allowing the creation of DNA from RNA, facilitating the study and treatment of RNA viruses like hepatitis B and HIV.

Retroelements in the Human Genome

• Role of Reverse Transcriptases: Significant in shaping the human genome through retroelements, sequences that originated from retroviruses.
• Horizontal Gene Transfer: Retroelements were transferred across species, not just from parent to offspring, impacting human biology and evolution.
• Recent Research: Studies show that human endogenous retroviruses, a class of retroelements, could be linked to neuropsychiatric diseases.

Reverse Transcriptase in Bacteria

• Discovery: The first bacterial reverse transcriptase was discovered in 1989.
• Types of Retroelements: Group II introns, retrons, and diversity generating retroelements in bacteria function similarly to those in humans.

Klebsiella pneumoniae and Bacteriophages

• Mechanism: When infected by bacteriophages, K. pneumoniae uses non-coding RNA with specific motifs to bind reverse transcriptase, creating DNA copies with the gene for Neo protein.
• Function of Neo Protein: Puts the bacterial cell in suspended animation, blocking replication and stopping bacteriophage infection.

Potential Applications

• Biotechnology and Medicine: The role of reverse transcriptase in bacterial defense against bacteriophages opens up new possibilities for combating antimicrobial resistance.
• Innovative Applications: Further research could lead to new therapeutic strategies and biotechnological tools, revealing novel mechanisms of genetic evolution and viral resistance.

Klebsiella pneumoniae Bacteria

• Klebsiella pneumoniae is a Gram-negative, rod-shaped bacterium commonly found in the human intestines where it generally does not cause harm. However, it can lead to severe infections, particularly in healthcare settings.
• Importance: This bacterium is significant due to its role in nosocomial (hospital-acquired) infections and its increasing resistance to multiple antibiotics.
• Capsule: Produces a prominent polysaccharide capsule, which is a key virulence factor.
• Oxygen Requirement: Facultative anaerobe

Habitat and Transmission

• Natural Habitat: Human gastrointestinal tract, respiratory tract, and various environmental sources such as soil and water.
• Transmission: Primarily through direct contact with contaminated surfaces, medical equipment, or person-to-person in healthcare settings. It can also spread through respiratory droplets.

Infections Caused

• Pneumonia: Particularly in hospitalized patients or those with weakened immune systems.
• Urinary Tract Infections (UTIs): Common in catheterized patients.
• Septicemia: Bloodstream infections that can lead to sepsis.
• Wound Infections: Including surgical site infections.
• Liver Abscesses: Particularly in individuals with diabetes or alcohol abuse.

Antibiotic Resistance

• Mechanisms of Resistance:
  • Beta-Lactamase Production: Enzymes that break down beta-lactam antibiotics (e.g., carbapenemase, ESBL - Extended-Spectrum Beta-Lactamase).
  • Efflux Pumps: Remove antibiotics from bacterial cells.
  • Modification of Target Sites: Changes in the bacterial cell that prevent antibiotic binding.
• Multidrug-Resistant Strains: Carbapenem-resistant Klebsiella pneumoniae (CRKP) and other strains resistant to multiple antibiotic classes are major public health concerns.

Sources: Hindu

PRACTICE QUESTION Q. The discovery of reverse transcriptase and its application in K. pneumoniae's defense against bacteriophages represents a significant advancement in our understanding of molecular biology. Comment.  (250 Words)