Silva S H, Vieira E C, Dias R S, Nicoli J R
Departmento de Microbiologia and *Departamento de Bioquímica-Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais and †Fundação Ezequiel Dias, Belo Horizonte MG, Brazil.
J Med Microbiol. 2001 Feb;50(2):161-164. doi: 10.1099/0022-1317-50-2-161.
Cholera vibrios sometimes survive, probably in low-level silent populations, in the small intestine of chronic carriers or pass through the gastrointestinal tract of a few individuals without causing diarrhoea or colonisation. To understand these situations, the present study used plate cultures (ex-vivo test) to investigate the frequency of appearance of an inhibitory halo against Vibrio cholerae produced by faecal specimens from 92 healthy volunteers (40 females, 52 males) aged 4-61 years. The frequency of inhibitory halo was 20.6% in the whole group. An apparently higher percentage (27.3%) was observed in the age range 20-40 years when compared with the range 4-19 years (10.7%), but not the range 41-61 years (20.0%). Frequency was significantly higher in males (30.8%) than females (7.5%). The dominant microbiota of a volunteer whose faeces produced an inhibitory halo was isolated by plate culture of decimal dilutions in an anaerobic chamber. Potential isolates of 26 apparently different morphologies were associated with germ-free NIH mice. One week later, the inhibitory test showed an antagonistic halo around the faeces from the associated animals, but not from the axenic mice. Of the 26 bacteria isolated, two (Lactobacillus sp. and Peptostreptococcus sp.) produced a compound antagonistic against V. cholerae in an in-vitro assay. When bi-associated with germ-free mice those strains eliminated the vibrio from the intestinal ecosystem in c. 5 days.
霍乱弧菌有时能存活下来，可能以低水平的沉默菌群形式存在于慢性携带者的小肠中，或者在少数个体的胃肠道中通过而不引起腹泻或定植。为了了解这些情况，本研究采用平板培养（体外试验）来调查92名年龄在4至61岁的健康志愿者（40名女性，52名男性）粪便标本产生的针对霍乱弧菌的抑菌圈出现频率。整个组的抑菌圈频率为20.6%。与4至19岁年龄组（10.7%）相比，20至40岁年龄组观察到的百分比明显更高（27.3%），但与41至61岁年龄组（20.0%）相比并非如此。男性（30.8%）的频率显著高于女性（7.5%）。通过在厌氧箱中对粪便进行十倍稀释的平板培养，分离出粪便产生抑菌圈的志愿者的优势微生物群。26种明显不同形态的潜在分离株与无菌NIH小鼠相关联。一周后，抑菌试验显示相关动物粪便周围有拮抗圈，而无菌小鼠粪便周围没有。在分离出的26种细菌中，两种（乳酸杆菌属和消化链球菌属）在体外试验中产生了对霍乱弧菌有拮抗作用的化合物。当与无菌小鼠双关联时，这些菌株在约5天内从肠道生态系统中清除了弧菌。
