Sørensen M
Nord Vet Med. 1979 Jan;31(1):25-34.
A comparative study of investigations from 1970 (before the prohibition against therapeutically used antibiotics as food additives for growth promotion) and from 1978 respectively proves that the prevalence of young pigs and calves with resistant E. coli has increased significantly from 61% to 92% and from 69% to 86% (tables I and II). Figures 1 and 2 show the prevalence of young pigs and calves with antibiotic resistant E. coli with resistance determinants towards sulfonamides, tetracycline, streptomycin, ampicillin, chloramphenicol, neomycin and furazolidone. This shows that the prevalence of young pigs with resistance determinants towards sulfonamides, tetracycline, streptomycin, ampicillin, and chloramphenicol has increased significantly from 1970 to 1978. The same facts apply to the calves. However, the increase in tetracycline resistance is not significant. Neomycin resistant E. coli for both young pigs and calves were only found in 1978. Figure 3 shows the distribution of the number of resistance determinants per young pig and calf with resistant E. coli. The figure shows the significant tendency that the pigs and calves investigated contain resistant E. coli with more resistance determinants in 1978 than in 1970. The distribution of R-factors among resistant E. coli seems to be reduced at first sight but a closer examination establishes that this only goes for R-factor mediated sulfonamide resistance (the experimental conditions may account for this). R-factor mediated streptomycin resistance has increased while R-factor mediated tetracycline resistance was at the same level. On the basis of literature the causes and risks of an increased distribution of antibiotic resistant E. coli are discussed.
一项分别对1970年（禁止将治疗用抗生素作为促进生长的食品添加剂之前）和1978年的调查进行的比较研究证明，携带耐药性大肠杆菌的幼猪和小牛的比例已从61%显著增至92%，从69%增至86%（表I和表II）。图1和图2显示了携带对磺胺类药物、四环素、链霉素、氨苄青霉素、氯霉素、新霉素和呋喃唑酮具有耐药决定因素的耐药性大肠杆菌的幼猪和小牛的比例。这表明，从1970年到1978年，携带对磺胺类药物、四环素、链霉素、氨苄青霉素和氯霉素具有耐药决定因素的幼猪的比例显著增加。小牛的情况也是如此。然而，四环素耐药性的增加并不显著。仅在1978年发现了幼猪和小牛携带对新霉素耐药的大肠杆菌。图3显示了每头携带耐药性大肠杆菌的幼猪和小牛的耐药决定因素数量的分布情况。该图显示了一个显著趋势，即1978年调查的猪和小牛所携带的耐药性大肠杆菌的耐药决定因素比1970年更多。乍一看，耐药性大肠杆菌中R因子的分布似乎有所减少，但仔细检查发现，这仅适用于R因子介导的磺胺类药物耐药性（实验条件可能对此有所解释）。R因子介导的链霉素耐药性有所增加，而R因子介导的四环素耐药性则处于同一水平。基于文献，讨论了耐药性大肠杆菌分布增加的原因和风险。
