The traditional way of protecting fish against disease is to inject them individually with a vaccine.

But this can be time-consuming and manpower-intensive.

Singapore researchers have come up with a way around this - using a tiny nano material.

They have found a way to package a vaccine for a common bacterium in tropical waters, tenacibaculum maritimum, into a material 100,000 times thinner than a strand of human hair. The bacterium causes the scales of infected fish to fall off and their mouths to disintegrate.

The new method will allow fish farmers to vaccinate their fish stocks by immersing them in a container of water containing the \"nanovaccine\". It then enters the fish through their gills and skin.

\"There is no need for skilled workers, and fewer workers are needed... making it cheaper,\" said Dr Jeffrey Seng, a senior lecturer at Nanyang Polytechnic\'s School of Chemical and Life Sciences. He led the development of the nanovaccine.

With vaccination, fish do not need to be fed antibiotics when they are sick, reducing the chance of drug residues reaching humans.

The nanovaccine was developed over the past two years. The nano material used is a combination of clay and chitosan, derived from crustacean shells. Tests found that it did not affect the health of the fish and was not toxic to human colon cell lines. All traces of residue in the fish disappeared after a month.

Source: Singapore Times // Original Article