Staphylococcus aureus enterotoxin production in raw, holder-pasteurized, and ultraviolet-c-treated donated human milk

Yahya Ahmad Y Almutawif, Benjamin Hartmann, Megan Lloyd, Ching Lai, Alethea Rea, Donna Geddes

Research output: Contribution to journalArticle

Abstract

BACKGROUND:
Some strains of Staphylococcus aureus can produce heat-stable enterotoxins that have been associated with gastritis and potentially necrotizing enterocolitis in preterm infants.

OBJECTIVES/HYPOTHESIS:
To assess the impact of different storage temperatures on S. aureus growth and enterotoxin production in raw, Holder-pasteurized (HP) and ultraviolet-C (UV-C)-treated donated human milk (DHM).

MATERIALS AND METHODS:
The milk samples from individual donors were pooled and divided into four equal portions. One portion was HP, the second was UV-C treated, the third was not treated, and the fourth was UV-C treated after being spiked with S. aureus. All samples were incubated at 37°C (18 hours) and 4°C (14 days). Bacterial colony count, enterotoxin A and B, and immune proteins were quantified.

RESULTS:
At 37°C, the colony count increased in HP DHM and decreased in raw and UV-C-treated DHM. At 4°C, colony counts in HP DHM reduced and were not detected in raw and UV-C-treated DHM from day 8 of incubation. No bacteria were detected in samples that were inoculated before UV-C treatment. Enterotoxin A was only detected in HP-DHM at 37°C from the 9th hour onward. Enterotoxin B was detected in one sample at the 15th hour. Immune protein concentrations were similar in raw and UV-C DHM, and were reduced in the HP DHM.

CONCLUSION:
UV-C-treated milk reduces S. aureus growth with similar kinetics to raw milk making it a promising emerging technique to eliminate bacteria while retaining essential immune proteins in DHM.
Original languageEnglish
Pages (from-to)262-270
Number of pages9
JournalBreastfeeding Medicine
Volume14
Issue number4
Early online date28 Feb 2019
DOIs
Publication statusPublished - 1 May 2019

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