Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, 4 Stigbøjlen, DK-1870 Frederiksberg C, Denmark.
Int J Syst Evol Microbiol. 2012 Feb;62(Pt 2):352-358. doi: 10.1099/ijs.0.028746-0. Epub 2011 Mar 25.
Avian haemolytic Actinobacillus-like organisms have tentatively been named Bisgaard taxon 26. Phenotypic information has been published on 65 strains of this taxon. In the current study, 31 isolates were selected for genotypic characterization. Thirty strains had the same rpoB sequence and only one strain diverged in 1 nt. The highest rpoB similarity to members of other taxa was 89.7 % to the type strain of Actinobacillus equuli subsp. haemolyticus and the similarity to the type strain of the type species, Actinobacillus lignieresii, was 88.2 %. The lowest 16S rRNA gene sequence similarity between strains of the group was determined in previous investigations to be 99.6 % and the highest similarities of 96.4 and 96.2 % outside the group were obtained to the reference strain of Actinobacillus genomospecies 2 and to the type strain of A. equuli subsp. equuli, respectively; 95.8-95.3 % similarity was obtained with the type strain of A. lignieresii. recN gene sequence similarities within the group were from 99.5 % (strains F66(T) and F64) to 99.8 % (strains F66(T) and F67) corresponding to genome similarities of 93.9-94.6 %, which are near the upper limit for species compared with other members of the Pasteurellaceae. The highest recN similarity outside the group (83.4 %) was observed to the type strain of Actinobacillus capsulatus, whereas the similarity to the type strain of A. lignieresii was 80.9 %, corresponding to genome similarities of 57.7 and 52.0 %, respectively. All isolates meet the phenotypic characters outlined for Actinobacillus (urease-, phosphatase- and porphyrin-positive, indole-negative, acid production from fructose, sucrose, maltose and dextrin). β-Haemolysis of bovine blood is observed and isolates may demonstrate in vitro satellitic growth, referred to as V-factor or NAD requirement. Isolates have been obtained from the upper respiratory tract of web-footed birds in which they may cause sinusitis, conjunctivitis and septicaemia. Based on the characterization reported, it is proposed that the isolates belong to a novel species, Actinobacillus anseriformium sp. nov., which includes taxon 26 and a V-factor-dependent strain. The major fatty acids of the type strain are C(16 : 1)ω7c, C(14 : 0), C(16 : 0) and C(14 : 0) 3-OH and/or iso-C(16 : 1) I, corresponding to the profile observed for the type strain of A. lignieresii. Five to 12 characters separate A. anseriformium from other taxa of Actinobacillus, with Actinobacillus ureae being most closely related; A. anseriformium can be differentiated from A. ureae based on haemolysis, β-glucosidase, and production of acid from (-)-D-sorbitol, trehalose and glycosides. The type strain of A. anseriformium is F66(T) ( = CCUG 60324(T) = CCM 7846(T)), which was isolated from conjunctivitis in a White Pekin duck.
禽类溶血性放线杆菌样生物体被暂命名为 Bisgaard 分类群 26。该分类群的 65 株菌株的表型信息已经发表。在目前的研究中，选择了 31 株分离株进行基因型特征分析。30 株具有相同的 rpoB 序列，只有 1 株在 1 个核苷酸处发生分化。与其他分类群成员的最高 rpoB 相似性为 99.6%，与溶血马流感亚种的模式株相似性为 88.2%。该组菌株的最低 16S rRNA 基因序列相似性在先前的研究中确定为 95.3%，与基因组种 2 的参考株和溶血马流感亚种的模式株的最高相似性分别为 96.2%和 96.4%；与模式株的相似性为 95.8-95.3%。该组内 recN 基因序列相似性从 99.5%（菌株 F66(T)和 F64）到 99.8%（菌株 F66(T)和 F67），相应的基因组相似性为 93.9-94.6%，与巴氏杆菌科的其他成员相比，接近种的上限。组外最高的 recN 相似性（83.4%）观察到与荚膜放线杆菌的模式株，而与模式株的相似性为 80.9%，相应的基因组相似性分别为 57.7%和 52.0%。所有分离株均符合放线杆菌（脲酶、磷酸酶和卟啉阳性，吲哚阴性，果糖、蔗糖、麦芽糖和糊精产酸）的表型特征。牛血β-溶血可见，分离株可能在体外表现出卫星生长，称为 V 因子或 NAD 需求。这些分离株是从蹼足鸟类的上呼吸道中获得的，它们可能引起鼻窦炎、结膜炎和败血症。基于报告的特征，建议这些分离株属于一种新的物种，即鹅源放线杆菌（Actinobacillus anseriformium）sp. nov.，它包括分类群 26 和一种依赖 V 因子的菌株。模式株的主要脂肪酸为 C(16 : 1)ω7c、C(14 : 0)、C(16 : 0)和 C(14 : 0) 3-OH 和/或 iso-C(16 : 1) I，与模式株的脂肪酸图谱相似。鹅源放线杆菌与其他放线杆菌属的种有 5-12 个特征差异，与 ureae 种最为密切相关；鹅源放线杆菌可以根据溶血、β-葡萄糖苷酶和（-）-D-山梨醇、海藻糖和糖苷的产酸来区分 ureae 种。鹅源放线杆菌的模式株为 F66(T)（=CCUG 60324(T)=CCM 7846(T)），它是从一只白北京鸭的结膜炎中分离出来的。
