Impact of vaccination during pregnancy and staphylococci concentration on the presence of Bacillus cereus in raw human milk

Abstract

Objective This study aimed to determine whether vaccination during pregnancy, prematurity, and staphylococci concentration influenced the presence of B. cereus or staphylococcal enterotoxins (SEs) in raw human milk from healthy mothers. Study design Human milk samples were collected from 152 healthy women. B. cereus, S. aureus and coagulase-negative staphylococci (CNS) were enumerated using selective agar culture media. The detection of B. cereus spores and SEs were determined using ELISA. Results CNS and B. cereus concentrations in milk from non-vaccinated mothers were higher than that from mothers vaccinated during pregnancy, but S. aureus did not differ. Prematurity did not affect B. cereus or staphylococci in human milk. S. aureus and CNS concentrations in human milk with the presence of B. cereus were higher than that with the absence of B. cereus. Viable B. cereus was present in 9.2% of raw human milk samples whereas SEs were not detected in any samples. Conclusions Vaccination during pregnancy and low concentration of staphylococci could reduce the risk of B. cereus in raw human milk. The screening of B. cereus in raw human milk must be performed before pasteurization to reduce the risk of B. cereus infection in preterm infants.

The Sporobiota of the Human Gut

“…[128][129][130] Using culture-dependent methods, B. cereus was identified in 9.2% of 152 raw donor milk samples. 131 Donor milk is pasteurized for 30 min at 62.5°C, also known as the Holder method. 132,133 However, multiple studies have shown that this method is not always effective in killing Bacillus spores.…”

Bacillus cereus as a Major Cause of Discarded Pasteurized Human Banked Milk: A Single Human Milk Bank Experience

“…B. cereus is an opportunistic human pathogen associated with local and systemic infections in immunosuppressed patients. Premature infants are highly susceptible to infection due to their poorly developed immune system and prolonged invasive procedures, such as mechanical ventilation or catheterization [ 9 , 10 ]. Infections of the bloodstream, lungs, central nervous system [ 1 , 11 , 12 , 13 , 14 ], and intestinal tract [ 2 ] have been described, some with fatal outcomes [ 9 , 15 ].…”

Quantitative Risk Assessment of Bacillus cereus Growth during the Warming of Thawed Pasteurized Human Banked Milk Using a Predictive Mathematical Model

“…Lowering the incidence of necrotizing enterocolitis in newborns fed PBM compared to that in babies fed milk formula is a significant advantage for this type of feeding [ 6 ]. On the other hand, due to the immaturity of the immune system in extremely-low-birth-weight neonates, they are at risk of opportunistic infections, such as B. cereus [ 7 , 8 , 9 , 10 , 11 , 12 ]. While in healthy newborns, feeding with PBM is temporary support in cases of the mother’s delayed or insufficient lactation, in very-low-birth-weight neonates, PBM represents the only option because breastfeeding is not possible.…”