Staphylococcal scalded skin syndrome related to an exfoliative toxin A- and B-producing strain in preterm infants

Abstract.

A previously well, spontaneously breathing premature infant (gestational age 25 weeks, birth weight 364 g, age 74 days) developed staphylococcal scalded skin syndrome (SSSS). A methicillin-sensitive strain of Staphylococcus aureus producing exfoliative toxins A and B (ETA, ETB) was isolated from a gastric aspirate and a pharyngeal swab. The disease recurred with a milder clinical picture 4 weeks later in the same patient while under steroid treatment. Cultures obtained from conjunctiva and pharynx were again positive for S. aureus. A second premature infant in an adjacent ward developed SSSS 2 weeks after the recurrence in the first patient. No other cases were observed thereafter. A total of 25 individuals who had contact with the first patient were screened for staphylococcal colonisation. S.aureus was isolated from the posterior part of the nasal cavity in 8 of the 25 contacts. These strains and the strain of the first patient were evaluated by PCR for the presence of genes encoding ETA and ETB. Expression of toxins was confirmed by gel electrophoresis and Western blot analysis. Purified toxins were injected into newborn mice to confirm toxin activity. Besides the strain isolated from the first patient, only one isolate from the medical staff was positive for the genes encoding ETA and ETB. Conclusion: the carrier of this strain had contact with both patients, suggesting that this individual was the vector between the two patients but not necessarily the source of the original infection. Strict infection control measures were implemented and no further spread of the disease occurred.