Human milk storage conditions and bactericidal activity: An experimental study

Area of Science:

• Neonatal care and nutrition
• Microbiology and immunology
• Food science and preservation

Background:

• Breast milk is vital for infant nutrition and immune defense.
• Extended breastfeeding is recommended, but stored milk is sometimes necessary.
• Understanding storage effects on antimicrobial properties is crucial for infant health.

Purpose of the Study:

• To evaluate the impact of polyethylene bags versus Pyrex bottles on breast milk's antimicrobial activity.
• To assess changes in effectiveness against common neonatal pathogens: Escherichia coli, Staphylococcus aureus, and Streptococcus agalactiae.
• To determine optimal short-term storage conditions for maintaining breast milk's protective qualities.

Main Methods:

• Prospective study involving 30 mothers and term infants.
• Manual milk expression into polyethylene bags and Pyrex bottles.
• Storage at 4°C for 0, 24, and 48 hours, followed by bactericidal activity assessment against E. coli, S. aureus, and S. agalactiae.

Main Results:

• No overall significant difference in colony counts between storage containers.
• Significant increase in S. agalactiae colonies at 48 hours in Pyrex bottles (p=0.003).
• Significant increase in S. aureus colonies at 48 hours in polyethylene bags (p=0.036).

Conclusions:

• Refrigerated storage for 24-48 hours significantly reduced bactericidal activity against S. agalactiae and S. aureus.
• Short-term human milk storage can compromise antimicrobial properties, varying by bacterial strain and container type.
• Further research is needed to establish optimal storage methods for preserving breast milk's immunological benefits.