Division of Clinical Chemistry, Niigata University Graduate School of Health Sciences, Niigata 951-8518, Japan.
Department of Nursing, Niigata University Graduate School of Health Sciences, Niigata 951-8518, Japan.
J Oral Biosci. 2021 Jun;63(2):161-168. doi: 10.1016/j.job.2021.03.001. Epub 2021 Mar 17.
To clarify the characteristics and growth of bacteria that may infiltrate liquid baby formula during feeding and after storage for more than 3 h, the transfer of oral bacteria through artificial nipples, and bacterial survival in liquid baby formula and a baby drink were examined immediately after drinking and after storage at 4 °C for 12 h and 24 h.
Thirteen human subjects (aged 19-24 years) were asked to drink approximately 50 mL of liquid baby formula and a baby drink, via the artificial nipple of a baby bottle. Samples of the remaining liquid after storage at 4 °C for 12 h and 24 h were inoculated onto blood agar plates and incubated anaerobically at 37 °C for 7 days. Genomic DNA was extracted from individual colonies, and the bacterial species were identified by 16S rRNA gene sequencing.
The mean concentrations of bacteria in the liquid baby formula were (2.6 ± 2.8) × 10 and (4.1 ± 6.6) × 10 colony-forming unit/mL after storage at 4 °C for 12 h and 24 h, respectively. Streptococcus (43.2%), Veillonella (9.3%), and Schaalia (8.2%) species were recovered from the remaining liquid baby formula after storage at 4 °C for 12 h. In contrast, no bacteria were detected in the remaining baby drink after storage at 37 °C for 24 h.
The levels of bacteria immediately after drinking and after storage at 4 °C for 12 h or 24 h were similar, suggesting that remaining liquid baby formula may be preserved safely in a refrigerator for more than 3 h.
为了阐明在喂养过程中和储存超过 3 小时后，可能渗透到液体婴儿配方奶粉中的细菌的特征和生长情况，通过人工奶嘴转移口腔细菌，以及细菌在液体婴儿配方奶粉和婴儿饮料中的存活情况，本研究在饮用后即刻以及在 4°C 储存 12 小时和 24 小时后，立即检查了这些液体的细菌存活情况。
13 名（年龄 19-24 岁）志愿者通过婴儿奶瓶的人工奶嘴饮用约 50mL 的液体婴儿配方奶粉和婴儿饮料。将储存于 4°C 12 小时和 24 小时后的剩余液体样本接种于血琼脂平板，并在 37°C 下进行厌氧菌孵育 7 天。从单个菌落中提取基因组 DNA，并通过 16S rRNA 基因测序鉴定细菌种类。
储存于 4°C 12 小时和 24 小时后，液体婴儿配方奶粉中的细菌浓度分别为（2.6±2.8）×10 和（4.1±6.6）×10 菌落形成单位/mL。在储存于 4°C 12 小时后，从剩余的液体婴儿配方奶粉中回收了链球菌（43.2%）、韦荣球菌（9.3%）和沙雷氏菌（8.2%）。相比之下，在 37°C 储存 24 小时后，剩余的婴儿饮料中未检测到细菌。
饮用后即刻和在 4°C 储存 12 小时或 24 小时后的细菌水平相似，这表明剩余的液体婴儿配方奶粉在冰箱中保存超过 3 小时是安全的。
