Gardner Brett R, Bachmann Nathan L, Polkinghorne Adam, Hufschmid Jasmin, Tadepalli Mythili, Marenda Marc, Graves Stephen, Arnould John P Y, Stenos John
Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia.
Major Mitchell Consulting, Buderim, QLD 4556, Australia.
Pathogens. 2023 Jun 29;12(7):893. doi: 10.3390/pathogens12070893.
The obligate intracellular bacterial pathogen has been identified in a few species of marine mammals, some of which are showing population declines. It has been hypothesized that in marine mammals is a distinct genotype that varies significantly from the typical terrestrial genotypes. It appears to lack an IS1111. Isolates originating from Australian marine animals have a distinctly non-Australian profile of multiple-locus variable-number tandem-repeat analysis (MLVA). Extracted DNA of Australian fur seal placental origin was sequenced using the Novaseq platform. Illumina 150 bp paired-end reads were filtered and trimmed with Trimgalore. The microbial community present in the sequenced genome was evaluated with Kraken and Bracken software using the NCBI database. A phylogenetic analysis was performed using 1131 core genes. Core genes were identified using Panaroo and inputted into Iqtree to determine the maximum-likelihood tree. A second phylogenetic tree was created using and using seven housekeeping genes. Results were compared with the Nine Mile RSA439 virulent genome. This new Australian marine mammal isolate of (PG457) appears to be a novel genotype that lacks IS1111 and has a distinct MLVA signature (ms26, ms27, ms28, ms30, and ms31). The presence of genes for multiple virulence factors appears to give this genotype sufficient pathogenicity for it to be considered a possible causative agent of abortion in Australian fur seals as well as a potential zoonotic risk.
这种专性细胞内细菌病原体已在几种海洋哺乳动物中被发现，其中一些种群数量正在下降。据推测，海洋哺乳动物体内的该病原体是一种独特的基因型，与典型的陆地基因型有显著差异。它似乎缺少IS1111。来自澳大利亚海洋动物的分离株在多位点可变数目串联重复序列分析（MLVA）中具有明显的非澳大利亚特征。使用Novaseq平台对源自澳大利亚海狗胎盘的DNA进行测序。Illumina 150 bp双端读段用Trimgalore进行过滤和修剪。使用Kraken和Bracken软件并利用NCBI数据库评估测序基因组中存在的微生物群落。使用1131个核心基因进行系统发育分析。使用Panaroo鉴定核心基因，并将其输入Iqtree以确定最大似然树。使用七个管家基因创建了第二个系统发育树。将结果与九英里RSA439强毒株基因组进行比较。这种新的澳大利亚海洋哺乳动物分离株（PG457）似乎是一种新型基因型，缺少IS1111且具有独特的MLVA特征（ms26、ms27、ms28、ms30和ms31）。多种毒力因子基因的存在似乎使这种基因型具有足够的致病性，足以被认为是澳大利亚海狗流产的可能病原体以及潜在的人畜共患病风险。
