Three of the four newborns that died at Ewha Womans University Medical Center’s intensive care unit on Saturday had a bacterial infection, the Korea Centers for Disease Control and Prevention (KCDC) said Tuesday.

KCDC said blood cultures of the babies taken before death revealed an antibiotic-resistant strain of Citrobacter freundii in an interim update. The detected bacteria belong to the gram-negative bacteria family, which the KCDC had previously suspected of on Monday.

Related : KCDC suspects bacterial infection behind death of 4 infants

Citrobacter freundii is usually transmitted through the respiratory tract, surgical areas, and urinary tract. Although the intestinal bacterium is common in adults, the organism can sometimes cause respiratory, urinary, and blood infections in those with weakened immune systems. Previous reports of medical staff transmitting the bacteria in hospitals have been reported in academia.

“We cannot conclude the direct relationship between the babies’ deaths and the bacterial infection found at this time. The exact cause of death will be identified through results of the autopsy by the National Forensic Service and additional epidemiological investigations by the KCDC,” the disease-control center said in a statement.

Further reports show the deceased infants before dying had low oxygen saturation, increased heart rate, and necrotizing enteritis – a medical condition in which a portion of the bowel dies in premature or unhealthy newborns. Necrotizing enteritis is often treated with antibiotics.

The KCDC is performing a DNA analysis to confirm the babies had the same bacterial infection and will announce the results in the afternoon. An additional epidemiological investigation on the medical staff of the neonatal intensive care unit is also underway to investigate the infection pathway and source, it added.

In the interim, KCDC said it would do its best to prevent the infections from spreading.

Four out of the 12 babies who were discharged or transferred to another hospital from the care unit at Ewha had the rotavirus – a virus that causes severe inflammation of the stomach and bowels, the KCDC said.

Medical institutions that took in infants from the neonatal intensive care unit at EUMC have been notified of the findings, it added.

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