妊娠女性阴道中两种德氏乳杆菌亚种的生物学特性

The biological characteristics of two Lactobacillus delbrueckii subspecies in the vagina of pregnant women

目的探讨妊娠女性阴道中德氏乳杆菌的生物学特性,以供临床进一步研究。方法采用质谱鉴定仪初步鉴定菌种,再用16S rRNA基因和一代测序技术进行确认,同时观察德氏乳杆菌在培养基上的生长特征、染色情况、生化反应和抑菌现象。结果在妊娠女性阴道中首次分离出德氏乳杆菌印度亚种和sunkii亚种。两种细菌16S rRNA基因扩增产物1438 bp中存在3个碱基的差异。两种细菌均为革兰阳性兼性厌氧长杆菌。德氏乳杆菌印度亚种菌落边缘不整齐、菌落粗糙,而德氏乳杆菌sunkii亚种菌落边缘整齐微凸起且中间凹陷、菌落湿润,都能产生α-溶血环。两种细菌均能产生精氨酸双水解酶1(ADH1)、精氨酸双水解酶2(ADH2s)、丙氨酸芳胺酶(AlaA)、丙氨酸—苯丙氨酸—脯氨酸芳胺酶(APPA),分解蔗糖(SAC)和D-葡萄糖(dGLU),同时奥普托欣耐受试验(OPTO)呈阳性,过氧化氢试验为阴性,能分解葡萄糖产酸。两种菌都能抑制金黄色葡萄球菌和大肠埃希菌的生长。结论两种德氏乳杆菌亚种核苷酸序列存在单个碱基差异,直接影响其部分生物学特性。

Objective To investigate the biological characteristics of Lactobacillus delbrueckii in the vagina of pregnant women for further clinical study.Methods The strains were initially identified using mass spectrometry,then confirmed with 16S rRNA gene and first-generation sequencing technology.The growth characteristics,staining,biochemical reaction and bacteriostasis of Lactobacillus delbrueckii on the medium were observed.Results Lactobacillus delbrueckii subsp.indicus and Lactobacillus delbruecki subsp.sunkii were isolated and identified from vaginas of pregnant women for the first time.There were differences in 3 bases in 1,438 bp of 16S rRNA gene amplification product between the two strains.Both the strains were Gram-positive facultative rod-shaped anaerobic bacillus.Lactobacillus delbrueckii subsp.indicus had irregular and rough colonies,while Lactobacillus delbruecki subsp.sunkii had neat and slightly raised colonies with concave middle area,and the colonies were wet;both could produce alpha-hemolysis ring.Both the strains could produce ADH1,ADH2s,AlaA and APPA,and decompose SAC and dGLU.They were positive for OPTO and negative for hydrogen peroxide test.They could break down glucose to produce acid.Both of them could inhibit the growth of Staphylococcus aureus and Escherichia coli.Conclusion There is a single base difference in nucleotide sequence between the two subspecies of Lactobacillus delbrueckii,which directly affects some of their biological characteristics.