Li Charles, Yan Xianghe, Lillehoj Hyun S
Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service-US Department of Agriculture, Beltsville, 10300 Baltimore Avenue, MD 20705 USA.
Environmental Microbial and Food Safety Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service-US Department of Agriculture, Beltsville, 10300 Baltimore Avenue, MD 20705 USA.
Gut Pathog. 2017 Nov 21;9:69. doi: 10.1186/s13099-017-0217-6. eCollection 2017.
is ubiquitous in nature. It is a normal inhabitant in the intestinal tract of animals and humans. As the primary etiological agent of gas gangrene, necrosis and bacteremia, causes food poisoning, necrotic enteritis (NE), and even death. Epidemiology research has indicated that the increasing incidence of NE in poultry is associated with the withdrawal of in-feed antibiotic growth promoters in poultry production in response to government regulations. The recent omics studies have indicated that bacterial virulence is typically linked to highly efficient conjugative transfer of toxins, or plasmids carrying antibiotic-resistance traits. Currently, there is limited information on understanding of host-pathogen interaction in NE caused by virulent strains of . Elucidating such pathogenesis has practical impacts on fighting infectious diseases through adopting strategies of prophylactic or therapeutic interventions. In this report, we sequenced and analyzed the genome of Del1 strain using the hybrid of PacBio and Illumina sequencing technologies.
Sequence analysis indicated that Del1 strain comprised a single circular chromosome with a complete 3,559,163 bp and 4 plasmids: pDel1_1 (82,596 bp), pDel1_2 (69,827 bp), pDel1_3 (49,582 bp), and pDel1_4 (49,728 bp). The genome had 3361 predicted coding DNA sequences, harbored numerous genes for pathogenesis and virulence factors, including 6 for antibiotic and antimicrobial resistance, and 3 phage-encoded genes. Phylogenetic analysis revealed that Del1 strain had similar genome and plasmid sequences to the CP4 strain.
Complete chromosomal and plasmid sequences of Del1 strain are presented in this report. Since Del1 was isolated from a field disease outbreak, this strain is a good source to identify virulent genes that cause many damaging effects of Clostridial infections in chicken gut. Genome sequencing of the chicken pathogenic isolates from commercial farms provides valuable insights into the molecular pathogenesis of as a gastrointestinal pathogen in food animals. The detailed information on gene sequencing of this important field strain will benefit the development of novel vaccines specific for -induced NE in chickens.
在自然界中普遍存在。它是动物和人类肠道中的正常居民。作为气性坏疽、坏死和菌血症的主要病原体，可导致食物中毒、坏死性肠炎（NE），甚至死亡。流行病学研究表明，家禽中NE发病率的上升与家禽生产中根据政府规定停用饲料中抗生素生长促进剂有关。最近的组学研究表明，细菌毒力通常与毒素或携带抗生素抗性特征的质粒的高效接合转移有关。目前，关于由强毒株引起的NE中宿主-病原体相互作用的了解有限。阐明这种发病机制对于通过采取预防或治疗干预策略抗击传染病具有实际意义。在本报告中，我们使用PacBio和Illumina测序技术的混合方法对Del1菌株的基因组进行了测序和分析。
序列分析表明，Del1菌株由一条完整的3,559,163 bp单环状染色体和4个质粒组成：pDel1_1（82,596 bp）、pDel1_2（69,827 bp）、pDel1_3（49,582 bp）和pDel1_4（49,728 bp）。该基因组有3361个预测的编码DNA序列，含有许多致病和毒力因子基因，包括6个抗生素和抗微生物抗性基因以及3个噬菌体编码基因。系统发育分析表明，Del1菌株的基因组和质粒序列与CP4菌株相似。
本报告展示了Del1菌株完整的染色体和质粒序列。由于Del1是从一次田间疾病爆发中分离出来的，该菌株是鉴定导致鸡肠道中梭菌感染产生许多破坏性影响的毒力基因的良好来源。对商业农场中鸡致病性分离株的基因组测序为作为食用动物胃肠道病原体的分子发病机制提供了有价值的见解。这一重要田间菌株的基因测序详细信息将有助于开发针对鸡中由引起的NE的新型疫苗。
