Hinton M, Hedges A J, Linton A H
J Appl Bacteriol. 1985 Jan;58(1):27-35. doi: 10.1111/j.1365-2672.1985.tb01426.x.
Dynamic changes in the Escherichia coli population in the calf gut were studied over 21 days in a group of 18 intensively-reared market calves. Isolates were identified by O-serogrouping, biotyping and resistogram patterns. Seventy O-serogroups were identified among nearly 3000 E. coli isolates examined and these were subdivided into 416 strains by means of their biotype and resistogram. Seventy-five per cent of these strains were detected only once or twice, which points to the continual replacement of the E. coli flora with strains that showed low persistence in the gut. The rise in the frequency of antibiotic resistance observed during the study was not due to a change in the proportion of resistant to sensitive strains in the gut flora. It was a consequence of the displacement of the original flora by multiply-resistant strains, which presumably originated from the calves' environment.
在一组18头集约化饲养的待售小牛中，对其肠道内大肠杆菌种群的动态变化进行了为期21天的研究。通过O血清型分类、生物分型和耐药谱模式对分离株进行鉴定。在检测的近3000株大肠杆菌分离株中，鉴定出70个O血清型，并根据其生物型和耐药谱将它们细分为416个菌株。其中75%的菌株仅被检测到一两次，这表明肠道内大肠杆菌菌群不断被在肠道内持久性低的菌株所取代。研究期间观察到的抗生素耐药性频率上升，并非由于肠道菌群中耐药菌株与敏感菌株比例的变化。这是由多重耐药菌株取代原始菌群导致的结果，这些多重耐药菌株可能源自小牛的饲养环境。
