本研究分析比较了农家家养鸡与大型养殖场鸡肠道菌群组成及抗四环素抗性基因在肠道菌群中的分布情况。通过454焦磷酸法对细菌16S rRNA V3区进行测序来分析肠道菌群的组成；用平板琼脂法筛选四环素耐药菌株，对其16S rRNA基因全长测序，并与RDP (Ribosomal Database Project)数据库比对进行菌种鉴定；聚合酶链反应(polymerase chain reaction，PCR)检测常见四环素耐药基因。家养鸡粪便中菌群香农多样性指数为5.321±0.590，养殖场鸡为4.398±0.440，前者显著大于后者(Mann-Whitney U test，P＝0.008)。从家养鸡和养殖场鸡粪便中随机分离到69株和65株四环素耐药菌株，后者四环素耐药菌的种类多于前者。家养鸡较养殖场鸡的肠道菌群更具多样性，而抗生素抗性基因在养殖场鸡的肠道菌群中分布更广泛。结果表明，不同饲养方式对鸡的肠道菌群有影响，对抗生素抗性基因的分布也有一定影响。

To analyze the microbial composition and the distribution of tetracycline resistant bacteria in the feces of chickens from small farmhouse and big feedlot, eight chickens from a small farmhouse and ten chickens from a big feedlot were enrolled. Fecal microbiota was analyzed through 454 pyrosequencing of 16S rRNA V3 region. Fourteen reported tetracycline resistance genes were tested by polymerase chain reaction (PCR). The mean Shannon diversity indexes of microbiota in chickens from a small farmhouse and a big feedlot were 5.321±0.590 and 4.398 ±0.440, respectively, with significant difference (Mann-Whitney U test, P＝0.008). Moreover, 69 and 65 tetracycline resistant isolates were randomly selected from chicken feces in small farmhouse and big feedlot, respectively. The species of tetracycline resistant bacteria isolated from chicken feces in the big feedlot were more diverse than those in the small farmhouse. The data concluded the wider dissemination of tetracycline resistant bacteria in the chickens from big feedlot, suggesting that more attentions should be paid to the changes in the microbiota and tetracycline resistant bacteria in the chickens from big feedlot and their influences on human health.