Asanuma H, Numazaki K, Nagata N, Hotsubo T, Horino K, Chiba S
Department of Pediatrics, Sapporo Medical University, Hokkaido, Japan.
Microbiol Immunol. 1996;40(3):201-4. doi: 10.1111/j.1348-0421.1996.tb03335.x.
Breast-fed infants are susceptible to human cytomegalovirus (HCMV) infection via breast milk. In our previous study, HCMV was isolated more frequently from breast milk at later than one month after delivery than from colostrum or early breast milk. To clarify the role of milk cells and whey in vertical infection by breast feeding, we separated breast milk into milk cells and whey and examined each fraction for the presence of HCMV. We collected breast milk from mothers who breast-fed their infants (aged from 3 days to 2 months). The breast milk was centrifuged and separated into the middle layer (layer of milk whey) and the pellet (containing milk cells). We attempted to isolate HCMV from whey and to detect HCMV immediate early (IE) DNA in both milk whey and cells. HCMV was isolated from 7 out of 35 (20.0%) whey samples and HCMV IE DNA was detected from 15 out of 35 (42.9%) whey and/or milk cells. Detection rates of HCMV IE DNA in the whey layer and milk cells were 39.1% (25 out of 64) and 17.2% (11 out of 64), respectively. HCMV IE DNA was not detected in colostrum, but was detected in breast milk samples one month after delivery. Therefore, cell-free HCMV shed into milk whey may have a more important role in vertical infection by breast milk than cell-associated HCMV in the milk.
母乳喂养的婴儿易通过母乳感染人巨细胞病毒（HCMV）。在我们之前的研究中，产后1个月以后的母乳中分离出HCMV的频率高于初乳或早期母乳。为了阐明乳细胞和乳清在母乳喂养垂直感染中的作用，我们将母乳分离为乳细胞和乳清，并检测各部分中是否存在HCMV。我们从母乳喂养婴儿（年龄3天至2个月）的母亲那里收集母乳。将母乳离心，分离为中间层（乳清层）和沉淀（含乳细胞）。我们试图从乳清中分离HCMV，并检测乳清和细胞中的HCMV即刻早期（IE）DNA。35份乳清样本中有7份（20.0%）分离出HCMV，35份乳清和/或乳细胞中有15份（42.9%）检测到HCMV IE DNA。乳清层和乳细胞中HCMV IE DNA的检出率分别为39.1%（64份中的25份）和17.2%（64份中的11份）。初乳中未检测到HCMV IE DNA，但在产后1个月的母乳样本中检测到。因此，分泌到乳清中的游离HCMV在母乳垂直感染中可能比乳汁中与细胞相关的HCMV发挥更重要的作用。
