García-Vela Sara, Martínez-Sancho Agustí, Said Laila Ben, Torres Carmen, Fliss Ismail
Department of Food Science, University of Laval, Quebec, QC QCG1V0A6, Canada.
Area of Biochemistry and Molecular Biology, OneHealth-UR Research Group, University of La Rioja, 26006 Logrono, La Rioja, Spain.
Pathogens. 2023 Jul 3;12(7):905. doi: 10.3390/pathogens12070905.
Necrotic enteritis (NE) caused by is one of the most common diseases of poultry and results in a huge economic loss to the poultry industry, with resistant clostridial strains being a serious concern and making the treatment difficult. Whole-genome sequencing approaches represent a good tool to determine resistance profiles and also shed light for a better understanding of the pathogen. The aim of this study was to characterize, at the genomic level, a collection of 20 isolates from poultry affected by NE, giving special emphasis to resistance mechanisms and production of bacteriocins. Antimicrobial resistance genes were found, with the genes (associated with tetracycline resistance) being the most prevalent. Interestingly, two isolates carried the gene associated with erythromycin resistance, which has only been reported in other Gram-positive bacteria. Twelve of the isolates were toxinotyped as type A and seven as type G. Other virulence factors encoding hyaluronases and sialidases were frequently detected, as well as different plasmids. Sequence types (ST) revealed a high variability of the isolates, finding new allelic combinations. Among the isolates, MLG7307 showed unique characteristics; it presented a toxin combination that made it impossible to toxinotype, and, despite being identified as , it lacked the housekeeping gene . Genes encoding bacteriocin BCN5 were found in five isolates even though no antimicrobial activity could be detected in those isolates. The gene of three of our isolates was similar to one previously reported, showing two polymorphisms. Concluding, this study provides insights into the genomic characteristics of and a better understanding of this avian pathogen.
由[未提及具体病因]引起的坏死性肠炎（NE）是家禽最常见的疾病之一，给家禽业造成巨大经济损失，耐药性梭菌菌株成为严重问题且使治疗困难。全基因组测序方法是确定耐药谱的良好工具，也有助于更好地了解病原体。本研究的目的是在基因组水平上对20株来自受NE影响家禽的分离株进行特征分析，特别关注耐药机制和细菌素的产生。发现了抗菌耐药基因，其中[未提及具体基因名称]基因（与四环素耐药相关）最为普遍。有趣的是，两株分离株携带与红霉素耐药相关的[未提及具体基因名称]基因，该基因仅在其他革兰氏阳性细菌中报道过。12株分离株毒素分型为A 型，7株为G型。还经常检测到其他编码透明质酸酶和唾液酸酶的毒力因子以及不同的质粒。序列类型（ST）显示分离株具有高度变异性，发现了新的等位基因组合。在分离株中，MLG7307表现出独特特征；它呈现出一种无法进行毒素分型的毒素组合，尽管被鉴定为[未提及具体菌种名称]，但它缺乏管家基因[未提及具体基因名称]。在5株分离株中发现了编码细菌素BCN5的基因，尽管在这些分离株中未检测到抗菌活性。我们的3株分离株的[未提及具体基因名称]基因与先前报道的一个基因相似，显示出两个多态性。总之，本研究提供了对[未提及具体菌种名称]基因组特征的见解，并更好地了解了这种禽病原体。
