Survival strategy of intracellular Rhodococcus equi : the role of virulence plasmid.

细胞内马红球菌的生存策略：毒力质粒的作用。

• 批准号: 12460140
• 负责人: TAKAI Shinji
• 金额: $ 9.22万
• 依托单位: Kitasato University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12460140/
• 关键词: Rhodococcu equi; virulence plasmid; DNA sequence; pathogenicity; intracellular bacteri; macrophage; horse; virulence; 病原性プラミスド; Rhodococcus equi; 食菌抵抗性

At least three virulence levels of Rhodococcus equi have been identified : virulence, intermediate virulence, and avirulence. Virulent R. equi is characterized by the presence of virulence-associated 15-to 17-kDa antigens (VapA), virulence plasmid DNA of 85 to 90 kb, and suppurative pneumonia in foals (mouse LD_<50>=10^6). R. equi strains of intermediate virulence are identified by a virulence associated 20-kDa antigen (VapB) and virulence plasmid DNA of 79 to 100 kb and are found in the submaxillary lymph nodes of pigs (mouse LD_<50>=10^7). To analyze the difference of virulence levels in R. equi, the virulence plasmid of the R. equi strain A3 of intermediate virulence (pREA3) was sequenced and compared with the DNA sequence of the virulence plasmid (p33701). pREA3 was 79,288 by and the plasmid encoded 71 open reading frames (ORFs). Of the 71 ORFs, 52 were found to be almost identical to those in the virulence plasmid (p33701). pREA3 also has a pathogenicity island containing 5 new virulence-associated protein (vap) genes [vapI, vapJ (2 copies), vapK, and vapL] located upstream of vapB. There was extensive homology in the region except the pathogenicity island between p33701 and pREA3. These results suggest that the difference in the structure and function of the pathogenicity islands between p33701 and pREA3 might be responsible for the difference in virulence levels of R. equi.

至少已经确定了三个毒力水平：毒力，中间的毒力和活力。毒力r。equi的特征是存在毒力相关的15至17 kDa抗原（VAPA），85至90 kb的毒力质粒DNA和小马驹中的化脓性肺炎（小鼠LD_ <50> = 10^6）。 R.中间毒力的均衡菌株通过毒力相关的20-kDa抗原（VAPB）和79至100 kb的毒力质粒DNA鉴定，并且在猪的颈颌面淋巴结中发现（小鼠LD_ <50> = 10^7）。为了分析Equi的毒力水平的差异，对中间毒力（PREA3）的R. equi A3的毒力质粒进行了测序，并与毒力质粒的DNA序列进行了比较（p33701）。 PREA3为79,288，质粒编码了71个开放式阅读框（ORF）。在71个ORF中，发现52个与毒力质粒中的ORF几乎相同（P33701）。 PREA3还具有一个致病岛，其中包含5个新的毒力相关蛋白（VAP）基因[VAPI，VAPJ（2份），VAPK和VAPL]，位于VAPB的上游。该地区有广泛的同源性，除了P33701和PREA3之间的致病岛。这些结果表明，p33701和pREA3之间致病岛的结构和功能的差异可能是R. equi的毒力水平的差异。

项目成果

Takai, S., et al.: "Rhodococcus equi pneumonia in a crossbred foal in Kumamoto: clinical isolates contained new virulence plasmids,90-kb type DI and type IV"Vet. Microbiol.. 82. 373-381 (2001)

Takai, S. 等人：“熊本杂交小马驹中的马红球菌肺炎：临床分离株含有新的毒力质粒、90-kb DI 型和 IV 型”兽医。

Yuyama, T., et al.: "Molecular epidemiology of virulent Rhodococcus epui in thoroughbred horses in Kagoshima"J. Vet. Med. Sci.. 64(8). 715-718 (2002)

Yuyama, T., et al.：“鹿儿岛纯种马中强毒力红球菌的分子流行病学”J.

Morton, AC et al.: "Epidemiology Of Rhodococcus equi Strains On Thoroughbred Horse Farms"Appl Environ Microbiol. 67. 2167-2175 (2001)

Morton, AC 等人：“纯种马场马红球菌菌株的流行病学”Appl Environ Microbiol。

Takai, S. et al.: "Identification of virulence-associated antigens and plasmids in Rhodococcus equi from AIDS patients and prevalence of virulent R. equi in soil collected from domestic animal farms in Chiang Mai."Am.J.TroMed.Hyg.. 66. 52-55 (2002)

Takai, S. 等人：“艾滋病患者马红球菌毒力相关抗原和质粒的鉴定以及从清迈家畜养殖场收集的土壤中马红球菌的毒力流行情况。”Am.J.TroMed.Hyg。

Flynn, O. et al.: "Virulence-associated protein characterisation of Rhodococcus equi isolated from bovine lymph nodes"Vet. Microbiol.. 78. 221-228 (2001)

Flynn, O. 等人：“从牛淋巴结中分离出的马红球菌的毒力相关蛋白特征”Vet。