Infectious Bronchitis (IB) is an acute, highly contagious disease associated with respiratory signs in young chickens and reduced egg production and quality in layers. The purpose of this study was to isolate and identify the infectious bronchitis virus in broiler flocks with respiratory diseases in four provinces of Iran. The specimens from forty IB suspected flocks from different regions of Isfahan, East Azerbaijan, Golestan, and Khuzestan provinces were collected, and the trachea, lung, and cecal tonsils were sampled. The samples were inoculated into 9- to 11-day—old embryonated chicken eggs. After collecting the allantoic fluid, RT-PCR was carried out to detect IB viruses. The results showed that IBVs were isolated from 30% of the flocks in these four provinces. The positive samples, according to a partial S1 gene sequence, were more investigated. Comparing nucleotide and amino acid sequences showed that the four isolates had the most similarity to the Pakistani 793/B strain (GI-13 lineage). The three isolates had the most considerable similarity in amino acid and nucleotide sequences to Iraqi and Iranian QX-like viruses (GI-19 lineage). Two isolates had 96 to 98% resemblance to Iranian variant-2 (GI-23 lineage) isolates. One isolate was found to belong to the Massachusetts serotype (GI-1 lineage) having 100% similarity in its amino acid sequence to the Massachusetts serotypes in GenBank. The phylogenetic relationship of the isolates shows complexity and diversity concerning different sequences and geographical regions.

传染性支气管炎 (IB) 是一种急性、高度传染性疾病，与幼鸡的呼吸道症状相关，并降低产蛋量和蛋鸡质量。本研究的目的是分离和鉴定伊朗四个省患有呼吸道疾病的肉鸡群中的传染性支气管炎病毒。采集了来自伊斯法罕、东阿塞拜疆、戈莱斯坦和胡齐斯坦省不同地区的 40 只 IB 疑似鸡群的标本，并对气管、肺和盲肠扁桃体进行了取样。将样品接种到 9 至 11 天大的鸡胚中。收集尿囊液后进行RT-PCR检测IB病毒。结果表明，在这四个省份的 30% 的鸡群中分离出了 IBV。阳性样本，根据部分 S1 基因序列，进行了更多的调查。比较核苷酸和氨基酸序列表明，四种分离株与巴基斯坦 793/B 菌株（GI-13 谱系）最相似。这三个分离株在氨基酸和核苷酸序列上与伊拉克和伊朗 QX 样病毒（GI-19 谱系）具有最相似的相似性。两个分离株与伊朗变异 2（GI-23 谱系）分离株有 96% 到 98% 的相似性。发现一种分离株属于马萨诸塞血清型（GI-1 谱系），其氨基酸序列与 GenBank 中的马萨诸塞血清型具有 100% 的相似性。分离株的系统发育关系显示出不同序列和地理区域的复杂性和多样性。这三个分离株在氨基酸和核苷酸序列上与伊拉克和伊朗 QX 样病毒（GI-19 谱系）具有最相似的相似性。两个分离株与伊朗变异 2（GI-23 谱系）分离株有 96% 到 98% 的相似性。发现一种分离株属于马萨诸塞血清型（GI-1 谱系），其氨基酸序列与 GenBank 中的马萨诸塞血清型具有 100% 的相似性。分离株的系统发育关系显示出不同序列和地理区域的复杂性和多样性。这三个分离株在氨基酸和核苷酸序列上与伊拉克和伊朗 QX 样病毒（GI-19 谱系）具有最相似的相似性。两个分离株与伊朗变异 2（GI-23 谱系）分离株有 96% 到 98% 的相似性。发现一种分离株属于马萨诸塞血清型（GI-1 谱系），其氨基酸序列与 GenBank 中的马萨诸塞血清型具有 100% 的相似性。分离株的系统发育关系显示出不同序列和地理区域的复杂性和多样性。发现一种分离株属于马萨诸塞血清型（GI-1 谱系），其氨基酸序列与 GenBank 中的马萨诸塞血清型具有 100% 的相似性。分离株的系统发育关系显示出不同序列和地理区域的复杂性和多样性。发现一种分离株属于马萨诸塞血清型（GI-1 谱系），其氨基酸序列与 GenBank 中的马萨诸塞血清型具有 100% 的相似性。分离株的系统发育关系显示出不同序列和地理区域的复杂性和多样性。