Gomes D A, Souza A M L, Lopes R V, Nunes A C, Nicoli J R
Departamento de Microbiologia, and bDepartamento de Biologia Geral, I.C.B., Universidade Federal de Minas Gerais, Belo Horizonte (MG), Brazil.
Folia Microbiol (Praha). 2006;51(2):141-5. doi: 10.1007/BF02932170.
To confirm if anaerobic G+-components are those responsible for the function of colonization resistance, obligate anaerobic G+- and G- -bacteria from normal dominant microbiota of human feces were isolated from three successive collections and then used in in vitro assays for antagonism against two enteropathogenic bacteria. The production of inhibitory diffusible compounds was determined on supplemented BHI agar and MRS agar media for G- - and G+-bacteria, respectively. Salmonella enterica subsp. enterica serovar Typhimurium and Shigella sonnei were used as indicators. G+-bacteria presented a higher overall antagonistic frequency against both pathogenic bacteria (57 and 64 % for S. enterica serovar Typhimurium and S. sonnei, respectively) when compared to G+-microorganisms but with a quite elevated variation between volunteers (0-100 %) and collection samples (40-72 and 40-80 % for S. enterica sv. Typhimurium and S. sonnei, respectively). On the other hand, only three among 143 G- -isolates tested showed antagonistic activity. The results showed that, at least in vitro, obligate anaerobic G+-components of the dominant human fecal microbiota present a higher potential for antagonism against the enteropathogenic models tested than do G- -bacteria.
为了确定厌氧革兰氏阳性菌成分是否是定植抗力功能的负责者，从人类粪便正常优势微生物群中分离出的专性厌氧革兰氏阳性菌和革兰氏阴性菌，取自连续三次的样本收集，然后用于体外试验，以对抗两种肠道致病菌。分别在补充了的脑心浸液琼脂和MRS琼脂培养基上，测定革兰氏阴性菌和革兰氏阳性菌产生的抑制性可扩散化合物。肠炎沙门氏菌亚种肠炎血清型鼠伤寒沙门氏菌和宋内志贺氏菌用作指示菌。与革兰氏阴性微生物相比，革兰氏阳性菌对两种病原菌的总体拮抗频率更高（鼠伤寒沙门氏菌和宋内志贺氏菌分别为57%和64%），但志愿者之间（0-100%）和收集样本之间（鼠伤寒沙门氏菌和宋内志贺氏菌分别为40-72%和40-80%）存在相当大的差异。另一方面，在测试的143株革兰氏阴性菌分离物中，只有三株显示出拮抗活性。结果表明，至少在体外，人类粪便优势微生物群中的专性厌氧革兰氏阳性菌成分比革兰氏阴性菌对所测试的肠道致病模型具有更高的拮抗潜力。
