Analysis of immunoreactivity to a Streptococcus equi subsp zooepidemicus M-like protein to confirm an outbreak of poststreptococcal glomerulonephritis, and sequences of M-like proteins from isolates obtained from different host species
Analysis of immunoreactivity to a Streptococcus equi subsp zooepidemicus M-like protein to confirm an outbreak of poststreptococcal glomerulonephritis, and sequences of M-like proteins from isolates obtained from different host species
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DOI：
10.1128/jcm.38.11.4126-4130.2000
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发表时间：
2000-11-01
影响因子：
9.4
通讯作者：
Beall, B
中科院分区：
文献类型：
--
作者：
Nicholson, ML;Ferdinand, L;Beall, B
1998年在巴西新塞拉纳爆发的链球菌感染后急性肾小球肾炎（PSGN）的病原体被发现可能是来自污染奶酪的马链球菌动物链球菌亚种（S.巴尔特等人，Lancet 355：1776-1780，2000）。在本研究中，我们使用了一个已知的表面暴露的毒力因子，以确认流行病学调查结果的血清学筛选。使用引物Banking先前表征的M样蛋白基因（J.F. Timoney等人，Infect. Immun. 63：1440-1445，1995），我们扩增并测序了M样蛋白（命名为Szp 5058）基因，发现其在四个独立的急性期PSGN患者分离株中是相同的。在PSGN爆发的44名患者中，33名患者的恢复期血清被发现含有对纯化的Szp 5058融合蛋白高度反应的抗体，而17名对照血清中只有1名（P < 0.0001），这表明Szp 5058在感染过程中表达，并进一步暗示该菌株是PSGN爆发的原因。Szp 5058与S.马链球菌zoopellicus SzpW 60的蛋白质，而预测的表面暴露部分之间的差异显着这两种蛋白质。szp 5058基因的5'端，包括其可变区，与来自与先前在英格兰爆发的PSGN相关的另一株的szp基因相同（M. Barham等人，Lancet i：945-948，1983），以及从分离自豚鼠的兰斯菲尔德C组型菌株中发现的相应szp序列。此外，szp 5058的高变（HV）部分与先前发表的来自马分离株的HV序列相同（J.A.步行者和J. F.蒂莫尼，美国59：1129-1133，1998）。另外3株S.马链球菌包括先前与PSGN爆发相关的另一种菌株在内的所有动物寄生虫都被发现含有不同的szp基因。其中两个szp基因的HV区域与从不同宿主物种中回收的分离株的szp区域相同。
The etiologic agent of a large 1998 outbreak of poststreptococcal acute glomerulonephritis (PSGN) in Nova Serrana, Brazil, was found likely to be a specific strain of Streptococcus equi subsp, zooepidemicus from contaminated cheese (S. Balter et al., Lancet 355:1776-1780, 2000). In the present study, we used a serologic screen for a known surface-exposed virulence factor to confirm the epidemiologic findings. Using primers Banking a previously characterized M-like protein gene (J. F. Timoney et al., Infect. Immun. 63:1440-1445, 1995), we amplified and sequenced the M-like protein (designated Szp5058) gene and found it to be identical among four independent acute-phase PSGN patient isolates. Convalescent-phase sera from 33 of 44 patients in the PSGN outbreak were found to contain antibodies highly reactive to a purified Szp5058 fusion protein, compared with 1 of 17 control sera (P < 0.0001), suggesting that Szp5058 was expressed during infection and further implicating this strain as the cause of the PSGN outbreak The predicted signal sequence and cell wall association motif of Szp5058 were highly conserved with the corresponding sequence from S. equi subsp. zooepidemicus SzpW60, while the predicted surface-exposed portions differed markedly between these two proteins. The 5' end of the szp5058 gene, including its variable region, was identical to the szp gene from another strain associated with a previous PSGN outbreak in England (M. Barham et al., Lancet i:945-948, 1983), and the corresponding szp sequence found from the Lancefield group C type strain isolated from a guinea pig. In addition, the hypervariable (HV) portion of szp5058 was identical to a previously published HV sequence from a horse isolate (J. A. Walker and J. F. Timoney, Am. J. Vet. Res. 59:1129-1133, 1998). Three other strains of S. equi subsp. zooepidemicus, including another strain previously associated with a PSGN outbreak, were each found to contain a distinct szp gene. Two of these szp genes had HV regions identical to szp regions from isolates recovered from different host species.