A Study on Microbial Aspects of Korean Human Milk by Collection Methods

수집방법에 따른 한국인 모유의 미생물 분포에 관한 연구

  • Published : 2003.09.01

Abstract

This study was carried out to evaluate the safety of Korean human milk. The microorganisms were identified from human milk of 149 healthy mothers by two collection methods, hand and pump expression. The means of total bacterial counts were 2.33x10$^4$ cfu/mL on the samples collected by the pump expression and 7.83xl0$^3$ cfu/mL on those collected by the hand expression. Therefore, the total bacterial counts of pump expression samples was 9.80xl0$^2$∼3.06x10$^4$ cfu/mL more than that of hand expression samples. The coliform counts of pump expression was 9.36xl0$^3$∼8.57xl0$^4$ cfu/mL more than that of hand expression. However, there was any significant differences of the lactic acid bacterial counts between the two samples collected by each methods. 100 strains of 5 patterns of total bacterial counts were isolated based on the morphology of colony in the standard plate count agar. 13 species were identified among the isolated strains. The dominant species in Korean human milk were Staphylococcus which 7 subspecies identified(81% in the rate of total bacteria, 1.07x10$^4$ cfu/mL). Other species identified were Micrococcus, Bacillus, Providencia, Pseudomonas, Yersinia and Acinetobacter. 36 strains of 6 patterns of lactic acid bacterial counts were isolated based on morphology of colony in the BCP agar. 7 species were identified among the isolated strains. The dominant species of lactic acid bacteria in Korean human milk were Lactobacillus brevis(50.9% in the rate of lactic acid bacteria, 4.72xl0$^4$ cfu/mL). Others species identified(49.1% lactic acid bacteria) were Lactobacillus curvatus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus acidophilus, Leuconostic lactis and Streptococcus salivarius subsp. thermophilus.

한국인 모유중 미생물을 분리 및 동정하여 미생물의 분포를 파악함으로써 영 유아의 건강에 대한 안정성을 확보하고자 하였다. 건강한 한국인 149명의 산모로부터 비유기간을 고려하여 유즙기에 의한 수집과 손에 의한 수집방법에 따라 모유를 나누어 미생물의 동정을 실시하였다. 유즙기로 수집한 경우 일반세균수는 평균 2.33${\times}$$10^4$ cfu/mL이구 손으로 착유시는 평균 7.83${\times}$$10^3$ c려/mL로서 유즙기를 이용하여 착유한 경우 평균 9.80${\times}$$10^2$∼3.06${\times}$$10^4$ cfu/mL 많이 존재하였으며, 대장균군 또한 유즙기를 이용하여 착유할 경우 평균9.36${\times}$$10^3$∼8.57${\times}$$10^4$ cfu/mL 많이 존재하는 것으로 나타났다. 반면에 유산균수는 평균 8.63${\times}$$10^2$∼7.64${\times}$$10^4$ cfu/mL로서 기계착유와 손착유 방법에 따른 차이점이 없었다. 일반세균의 동정은 산모로부터 수집된 모유를 Standard plate count agar를 이용하여 콜로니의 형태학적 특성에 따라 5가지 형태로 나누어 100개군으로 분리하였으며, Microbial Identification System(MIDI)을 이용하여 일반세균군을 동정한 결과, 휴 13개 균종으로 분포하고 있었으며, 그 중 Staphylococcus속이 7가지의 아종으로 전체 일반세균의 81% (1.07${\times}$$10^4$ cfu/mL)로서 가장 많이 존재하고 있는 것으로 나타났다. 그 밖에 Mcrococcus속, Bacillus속, Providencia속, Pseudomonas속, Yersinia속 및 Acinetobacter속이 각각 1종씩 검출되었다. 유산균의 동정은 BCP agar를 이용하여 콜로니의 형태학적 특성에 따라 6가지 형태로 나누어 36개군의 유산균군을 분리하였다. 그리고 Bergey's Manual 및 API 50CH system을 이용하여 생리적 및 생화학적 동정을 실시한 결과, 총 7개 균종으로 분포하고 있었으며, Lactobacillus brevis 균주간 전체 유산균중 50.9% (4.72${\times}$$10^4$ cfu/mL)로서 가장 많이 존재하고 있는 것으로 나타났다. 그 밖에 Lactobacillus curvatus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus acidophiiu 등 85.1%(7.89x$10^4$ cfu/mL)가 간균으로 분포하고 있었으며 구균으로는 Leuconostoc lactis와 Streptococcus salivarius subsp. thermophilus가 총 14.9% (1.39${\times}$$10^4$ cfu/mL)분포하고 있는 것으로 동정되었다.

Keywords

References

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