Gillmore J D, Gordon F B
Appl Microbiol. 1975 Mar;29(3):358-67. doi: 10.1128/am.29.3.358-367.1975.
Alterations in selected aerobic and anaerobic fecal microflora of the mouse were determined during exposure to hyperoxic and normoxic hypo- and hyperbaric environments. Examination of fecal cultures obtained during exposure for 6 weeks to either 60 or 77% oxygen concentration 1 atmosphere absolute revealed little alteration in the aerobic or anaerobic flora. There appeared to be only a retardation in the reduction of the Klebsiella-Enterobacter flora which normally occurs after weaning. During exposure to hypobaric environments (100% O-2, 0.2 atmosphere absolute), significant alterations in concentrations of Escherichia coli, slow lactose fermenters, Klebsiella-Enterobacter, and enterococci were found in some instances. All alterations were toward increased concentrations. Variations in concentrations of different colony types of obligately anaerobic gram-positive (anGPR) and gram-negative (anGNR) rods cultured during the same experiments also occurred. One colony type of anGPR appeared to decrease while a second type increased in numbers. Concentrations of three colony types of anGNR were generally, but not always, increased. During hyperbaric exposure (2.8% O-2, 7.5 atmospheres absolute), increased concentrations of Klebsiella-Enterobacter, E. coli, slow lactose fermenters and enterococci were also noted. Changes in numbers of both colony types of anGPR, when occurring, were in the direction of lower numbers. Alteration in numbers of anGNR were in both directions but were more frequent in the direction of higher numbers. After return to normal air for 4 weeks of either hypo- or hyperbaric exposure, fecal concentrations of all organisms tended to revert toward control values with the exception of the anGPR which remained in lower concentrations after termination of the hyperbaric exposure. These observations indicate that, despite the great variation in the fecal flora among individual mice, it is possible to discover the effects induced by altered gaseous environments.
在小鼠暴露于高氧、常氧低压和高压环境期间，测定了其粪便中部分需氧和厌氧微生物区系的变化。对暴露于6周、氧气浓度为60%或77%（绝对压力1个大气压）环境下所获取的粪便培养物进行检查发现，需氧或厌氧菌群几乎没有变化。断奶后通常会出现的克雷伯菌属 - 肠杆菌属菌群数量减少现象似乎只是有所延迟。在暴露于低压环境（100% O₂，绝对压力0.2个大气压）期间，某些情况下发现大肠杆菌、缓慢乳糖发酵菌、克雷伯菌属 - 肠杆菌属和肠球菌的浓度有显著变化。所有变化均朝着浓度增加的方向。在同一实验中培养的专性厌氧革兰氏阳性（anGPR）和革兰氏阴性（anGNR）杆菌不同菌落类型的浓度也出现了变化。一种anGPR菌落类型数量似乎减少，而另一种数量增加。三种anGNR菌落类型的浓度通常（但并非总是）增加。在高压暴露（2.8% O₂，绝对压力7.5个大气压）期间，也注意到克雷伯菌属 - 肠杆菌属、大肠杆菌、缓慢乳糖发酵菌和肠球菌的浓度增加。当出现变化时，两种anGPR菌落类型数量的变化方向是减少。anGNR数量的变化方向既有增加也有减少，但朝着增加方向的变化更为频繁。在低压或高压暴露后恢复正常空气4周后，除了高压暴露结束后anGPR浓度仍较低外，所有生物体的粪便浓度都趋于恢复到对照值。这些观察结果表明，尽管个体小鼠的粪便菌群存在很大差异，但仍有可能发现气态环境改变所诱导的影响。
