Christensen Henrik, Blackall Patrick J, Bisgaard Magne
Department of Disease Biology, University of Copenhagen, Frederiksberg C, Denmark.
Res Microbiol. 2009 Jun;160(5):315-21. doi: 10.1016/j.resmic.2009.05.006. Epub 2009 Jun 30.
Avian haemophili demonstrating in vitro satellitic growth, also referred to as the V-factor or NAD requirement, have mainly been classified with Avibacterium paragallinarum (Haemophilus paragallinarum), Avibacterium avium (Pasteurella avium), Avibacterium volantium (Pasteurella volantium) and Avibacterium sp. A (Pasteurella species A). The aim of the present study was to assess the taxonomic position of 18 V-factor-requiring isolates of unclassified Haemophilus-like organisms isolated from galliforme, anseriforme, columbiforme and gruiforme birds as well as kestrels and psittacine birds including budgerigars by conventional phenotypic tests and 16S rRNA gene sequencing. All isolates shared phenotypical characteristics which allowed classification with Pasteurellaceae. Haemolysis of bovine red blood cells was negative. Haemin (X-factor) was not required for growth. Maximum-likelihood phylogenetic analysis including bootstrap analysis showed that six isolates were related to the avian 16S rRNA group and were classified as Avibacterium according to 16S rRNA sequence analysis. Surprisingly, the other 12 isolates were unrelated to Avibacterium. Two isolates were unrelated to any of the known 16S rRNA groups of Pasteurellaceae. Two isolates were related to Volucribacter of the avian 16S rRNA group. Seven isolates belonged to the Testudinis 16S rRNA group and out of these, two isolates were closely related to taxa 14 and 32 of Bisgaard, whereas four other isolates were found to form a genus-like group distantly related to taxon 40 and one isolate remained distantly related to other members of the Testudinis group. One isolate was closely related to taxon 26 (a member of Actinobacillus sensu stricto). The study documented major genetic diversity among V-factor-requiring avian isolates beyond the traditional interpretation that they only belong to Avibacterium, underlining the limited value of satellitic growth for identification of avian members of Pasteurellaceae. Our study also emphasized that these organisms will never be isolated without the use of special media satisfying the V-factor requirement.
表现出体外卫星状生长（也称为V因子或烟酰胺腺嘌呤二核苷酸需求）的禽嗜血杆菌，主要已被归类为副鸡禽杆菌（副鸡嗜血杆菌）、鸟禽杆菌（鸟巴斯德菌）、飞行禽杆菌（飞行巴斯德菌）和A种禽杆菌（A种巴斯德菌）。本研究的目的是通过传统表型试验和16S rRNA基因测序，评估从鸡形目、雁形目、鸽形目和鹤形目鸟类以及红隼和鹦鹉类鸟类（包括虎皮鹦鹉）中分离出的18株未分类的类嗜血杆菌样生物的V因子需求菌株的分类地位。所有分离株都具有表型特征，可归类于巴斯德菌科。牛红细胞的溶血试验为阴性。生长不需要血红素（X因子）。包括自展分析在内的最大似然系统发育分析表明，6株分离株与禽16S rRNA组相关，根据16S rRNA序列分析被归类为禽杆菌属。令人惊讶的是，其他12株分离株与禽杆菌属无关。2株分离株与巴斯德菌科任何已知的16S rRNA组均无关。2株分离株与禽16S rRNA组的伏翼杆菌属相关。7株分离株属于龟鳖16S rRNA组，其中2株分离株与比斯加德分类单元14和32密切相关，而另外4株分离株形成了一个与分类单元40远缘相关的类属群，1株分离株与龟鳖组的其他成员远缘相关。1株分离株与分类单元26（严格意义上的放线杆菌属成员）密切相关。该研究记录了需要V因子的禽分离株之间存在主要的遗传多样性，这超出了传统观点，即它们仅属于禽杆菌属，强调了卫星状生长在鉴定巴斯德菌科禽成员方面的有限价值。我们的研究还强调，如果不使用满足V因子需求的特殊培养基，这些生物将永远无法分离出来。
