Professor Naomi Datta

Article excerpt

Bacteriologist who worked on the problem of drug resistance

Naomi Datta was a bacteriologist who did pioneering work on how bacteria work, why they cause disease and how we might prevent them doing so. Her work on plasmids (portions of bacterial DNA), which explained why bacteria become so rapidly resistant to all available antibiotics and provides an explanation for the origin of MRSA, earned her international fame in her field. She continued this work supported by the Medical Research Council throughout her career and it eventually formed a large part of the early work on the important subject of bacterial genetics.

Naomi Goddard was born in London in 1922, and was educated at St Marys Wantage, University College London and at the West London School of Medicine, where she met Prakash Datta, a fellow medical student, whom she married in 1943. After qualifying, her first post was at the Public Health Laboratory Service at Colindale, where she worked on the serological identification of salmonella isolates.

In 1959 she joined the department of bacteriology at the Royal Postgraduate Medical School, Hammersmith (now part of Imperial College). There she started work on a project stimulated by the work of T Watanabe in Japan, who had reported that resistance to several different antibiotics was being transmitted at the same time among dysentery bacilli.

Datta focused on plasmids small circular portions of bacterial DNA that lie attached to the cell membrane separate from the main bacterial chromosome. They divide independently of the bacterial chromosome and are then transmitted to neighbouring bacterial cells by several different mechanisms. When first studied in Escherichia coli and similar bowel bacteria, they were transmitted by conjugation. In this, they are injected by short tubes called pili that stick out from the bacterial surface into another bacterial cell. Plasmids could also be spread in bacteriophages, the viruses of bacteria, and also by direct bacterium-to-bacterium contact.

Towards the end of her work, Datta also investigated transposons, which are small segments of DNA that can jump from one position on the chromosome or plasmid to another, but are not self-replicating in the same way as plasmids. Plasmids may exist independently of the main chromosome in the bacterial cell but they may also be integrated into the chromosome when they add genes to the chromosomal set. …