Why in News?

• Recently, a new study has found that the origin and spread of Colistin resistant bacteria in human gut is majorly on account of Poultry.

What is Colistin?

• Colistin is a last-resort anti-biotic that is commonly used for treating gram negative infections in humans like Pneumonia, meningitis and other infections caused by E.coli etc
• Besides, use of Colistin is rampant in poultry where it is used as growth promoter and for disease prevention. (Tylosin is another antibiotic used as growth promoter)

Colistin-Resistance in Bacteria:

• Recently it has been found that bacterial strain Klebsiella pneumonia that lives in human gut has developed resistance to colistin.
• The origin of colistin-resistance in human gut Bacteria Includes

1. Hospitals
2. Food

• Poultry consumption
• Vegetables that contains Colistin-resistant Klebsiella bacteria:
  • This is because poultry litter is used as manure for growing vegetables.
  • Colistin-resistant bacteria of hospital origin do not respond to any of the antibiotics, including carbapenem while colistin-resistant bacteria of food origin will respond to carbapenem.

How resistance is Spread?

• The mutation in the mgrB gene confers colistin resistance to Klebsiella bacteria.
• Besides in 3% of the cases colistin-resistance in Klebsiella bacteria is due to mutation in mcr gene.

Significance of the Study:

• So far it was believed that the mutation in the mgrB gene or other chromosomal genes are the reason behind colistin resistance in Klebsiella bacteria.
• Till date, there is no evidence to suggest that the mgrB gene mutation spreads from food to human Klebsiella bacteria.
• But this study has found mgrB gene mutation in food Klebsiella bacteria. This shows that mgrB gene mutation also spreads from food to human Klebsiella bacteria.