Neonatal necrotizing enterocolitis associated with delta toxin-producing methicillin-resistant Staphylococcus aureus

Area of Science:

• Neonatal Medicine
• Infectious Diseases
• Microbiology

Background:

• Delta toxin-producing coagulase-negative staphylococci have been linked to necrotizing enterocolitis in neonates.
• Necrotizing enterocolitis is a serious gastrointestinal condition affecting newborns, particularly preterm infants.

Purpose of the Study:

• To investigate the potential role of methicillin-resistant Staphylococcus aureus (MRSA) in neonatal necrotizing enterocolitis.
• To characterize MRSA isolates from preterm infants presenting with a specific clinical syndrome.

Main Methods:

• Clinical case identification of three preterm infants with pustular dermatitis, bacteremia, and necrotizing enterocolitis.
• Microbiological analysis of MRSA isolates from skin, blood, catheters, and stool.
• Molecular characterization of MRSA isolates, including plasmid profiling, enterotoxin production, antibiotic susceptibility, and delta toxin activity.
• Western blot analysis for delta toxin confirmation and enzyme-linked immunoassay for delta-like toxin in Staphylococcus epidermidis.

Main Results:

• Three preterm infants presented with a similar clinical syndrome including pustular dermatitis, bacteremia, and necrotizing enterocolitis.
• MRSA was isolated from skin, blood, catheters, and stool in these infants.
• All MRSA isolates shared identical microbiologic profiles, produced enterotoxins A and B, and exhibited delta toxin hemolytic activity.
• Staphylococcus epidermidis isolated from stool did not produce delta-like toxin.

Conclusions:

• Delta toxin-producing MRSA may be an emerging etiologic agent in neonatal necrotizing enterocolitis.
• The findings suggest a potential shift or expansion in the pathogens associated with this severe neonatal condition.
• Further investigation is warranted to confirm the role of MRSA in necrotizing enterocolitis.