白羽肉鸡小肠内容物中致病性大肠杆菌的鉴定及基因组分析

Identification and Genomic Analysis of Pathogenic Escherichia coli in Small Intestinal Content of White Feather Broilers

旨在分析死亡白羽肉鸡肠道中的致病微生物,明确白羽肉鸡的死因,为白羽肉鸡的科学防病和治病提供新思路。采集养鸡场病死白羽肉鸡的肠道内容物,利用宏基因组测序、序列拼接、分箱技术、进化树分析、物种注释鉴定白羽肉鸡肠道中的致病微生物,通过基因组毒力基因和耐药基因的注释,阐述病原微生物的致病和耐药机制。结果显示:病死白羽肉鸡肠道内容物样品中检出的致病微生物为禽类致病性大肠杆菌(avian pathogenic Escherichia coli),经序列拼接和分箱技术得到病原菌全基因组序列,大小为4 998 208 bp,完整度为99.23%。该菌含有毒力基因192种,主要编码鞭毛、纤毛合成相关蛋白、定植相关蛋白、菌素合成相关蛋白,含有耐药基因88种,主要涉及28类抗生素的耐药,表明上述种类抗生素对感染禽类致病性大肠杆菌的白羽肉鸡无治疗作用,最终导致白玉肉鸡死亡。本研究利用宏基因测序技术可有效分析白羽肉鸡的致病微生物及致病、耐药机制,可在白羽肉鸡发病早期帮助养殖者了解病因,并有针对性地指导科学用药,减少经济损失。

This experiment was conducted to analyze the pathogenic microorganisms in the intestines of dead white feather broilers,clarify the cause of death of white feather broilers,and provide new ideas for scientific disease prevention and treatment of white feather broilers.Intestinal contents of died white feather broilers were collected from a chicken farm,then metagenomic sequencing,sequence splicing,box splitting technology,evolutionary tree analysis,and species annotation were used to identify pathogenic microorganisms in the intestine of white feather broilers.The pathogenic and drug resistance mechanisms of pathogenic microorganisms were elucidated through annotation of genome virulence genes and drug resistance genes.The results showed that the pathogenic microorganism detected in the intestinal contents of diseased white feather broiler chickens was avian pathogenic Escherichia coli.The entire genome sequence of the pathogen was obtained through sequence splicing and box splitting techniques,with a size of 4998208 bp and an integrity of 99.23%.This bacterium contains 192 virulence genes,mainly encoding flagella,cilia synthesis related proteins,colonization related proteins,and bacteriocin synthesis related proteins.It contains 88 resistance genes,mainly involving 28 types of antibiotic resistance,indicating that the above types of antibiotics have no therapeutic effect on white feather broilers infected with pathogenic Escherichia coli in poultry,ultimately leading to the death of white jade broilers.This study utilizes macro gene sequencing technology to effectively analyze the pathogenic microorganisms,pathogenesis,and drug resistance mechanisms of white feather broilers.It can help breeders understand the etiology in the early stages of white feather broiler disease,and provide targeted guidance for scientific medication to reduce economic losses.