A newborn became ill after he acquired a type of E. coli bacteria from his mother during delivery, one that is typically linked to food poisoning, Swiss researchers report.

The mother was infected with a strain of E. coli that produces the shiga toxin, a toxic substance that can cause diarrhea and kidney failure.

While the mother did not have any symptoms, her baby boy began vomiting two days after birth, and within a week developed kidney
failure and seizures. The baby was diagnosed with hemolytic-uremic syndrome, a condition caused by the shiga toxin.

Tests of stool samples from the mother and infant showed that both were infected with the same strain of shiga toxin-producing E. coli, O146:H28.

The less virulent nature of this bacterial strain meant the mother could carry the bug without showing symptoms. But in the gut of her newborn — which is free from germs until birth — the bacterium could proliferate without competition from other bugs

“It could easily expand and multiply because the bowel was sterile,” said study researcher Dr. Giacomo Simonetti of Bern University Hospital in Switzerland. The newborn’s gut may have allowed a larger-than-normal amount of bacteria to grow, resulting in illness, Simonetti said. The baby was kept well-hydrated and given medication for the seizures. He recovered and left the hospital in good condition 11 days after birth.

It is not known how or when the mother acquired this strain of E. coli, but she has an older son who did not have symptoms of hemolytic-uremic syndrome when he was born, Simonetti said.

Only a few other cases of mother-to-child transmission of shiga toxin-producing E. coli have been reported in the past, the first occurring in France in 2005.

Other types of bacteria are known to pass from mother to child during childbirth, including herpes simplex virus and group B streptococcus, Johnson said.

The new report will be published in the January issue of the journal Clinical Infectious Diseases.