Rise and fall of cholera-causing bacteria lineage
- Researchers identify the decline of antimicrobial resistance in O139 as a key determining factor in its downfall.
- It is a life-threatening infectious disease and a public health hazard.
- Caused by comma-shaped bacterium known as Vibrio cholerae.
- More than two hundred serogroups of this bacterium are known, of which only O1 and O139 are known to cause such infection that leads to epidemics and pandemics.
- Other causes mild cholera-like diarrhoea and food-associated outbreaks.
- O1 was responsible for seven pandemic waves, only to be temporarily displaced by O139.
- This emerged late and came up around 1992.
- It was first spotted in Chennai (then Madras).
- Researchers have studied genome of O139 and traced reasons for its dying down after taking over from O1.
- First related to type of cholera toxin it produced
- Second is related to loss of anti-microbial resistance.
- The study points to AMR as a factor that can decide success of certain populations of bacteria that can produce large outbreaks of disease.
- Continuous surveillance is necessary to monitor if any of the serotypes are gaining antibiotic resistance over time.
- Vaccines and treatments need to be regularly re-evaluated for efficiency to any newly evolving variants.