Successive changes in aerobic and anaerobic bacterial counts and changes in the generic composition of the epimural community in lambs from 1 to 10 weeks were determined. Bacterial culture counts revealed a predominantly anaerobic community, with the mean anaerobic count being 1.4 X 10(7) CFU/cm2 of tissue surface. The aerobic count was highest at 1 week of age and declined significantly thereafter to a mean of 1.8 X 10(4) CFU/cm2, thus representing only 0.13% of the mean anaerobic count after week 1. Of the 345 strains isolated anaerobically at 1, 2, 4, 6, 8, and 10 weeks of age, 47, 32, 12, 32, 2, and 5% were capable of growth in a partially reduced medium, indicating a reduction in the number of facultative anaerobes with time. The majority of isolated strains were identified as belonging to genera commonly isolated from rumen contents. In some instances, however, strains did not correspond to previously described species, and some genera were present in proportions different from those expected in rumen fluid. At three of the sampling times, one genus was dominant, constituting 45 to 55% of the isolates. These dominant isolates were Streptococcus bovis, Bacteroides sp., and an anaerobic Streptococcus sp. for weeks 1, 2, and 10, respectively. During the transition period (weeks 4 to 8), two or more groups were codominant.
展开▼
机译：确定了有氧和无氧细菌计数的连续变化和羔羊硬膜外群落的一般组成在1至10周内的变化。细菌培养物计数显示主要为厌氧菌，平均厌氧菌数为组织表面的1.4 X 10（7）CFU / cm2。有氧菌数在1周龄时最高，此后显着下降至平均1.8 X 10（4）CFU / cm2，因此仅占第1周后平均厌氧菌数的0.13％。在第2、2、4、6、8和10周龄时，47、32、12、32、2和5％能够在部分还原的培养基中生长，表明兼性厌氧菌的数量随时间减少。大部分分离出的菌株被鉴定为属于通常从瘤胃内容物中分离出的属。但是，在某些情况下，菌株与先前描述的物种不符，某些属的比例与瘤胃液中所预期的比例不同。在三个采样时间中，一个属占主导地位，占分离株的45％至55％。这些主要分离株是牛链球菌，拟杆菌属和厌氧链球菌。第1、2和10周。在过渡期间（第4到第8周），两组或更多组占主导地位。
展开▼
