Microbiology Service and Reference Laboratory for Meningococcal Infections of the Basque Country, Hospital Donostia, San Sebastián, Spain.
PLoS One. 2009 Dec 30;4(12):e8501. doi: 10.1371/journal.pone.0008501.
Neisseria meningitidis diversifies rapidly, due to its high recombination rates. The aim of this study was to analyze the possible impact of two vaccination campaigns (a once-off A/C polysaccharide vaccination campaign in people aged 18 months to 20 years old in 1997, and a meningococcal C conjugate vaccination campaign in children aged < or = 6 years old from 2000 to 2008) on diversification of the population of invasive isolates obtained between 1997 and 2008. All of the 461 available isolates were included (2, 319, 123, 11 and 6 belonging to serogroups A, B, C, Y and W-135, respectively).
METHODOLOGY/PRINCIPAL FINDINGS: The isolates were analyzed for diversity using multilocus sequence typing, eBURST and the S.T.A.R.T.2 program. One hundred and seven sequence types (ST) and 20 clonal complexes were obtained. Five different STs (ST11, ST8, ST33, ST1163 and ST3496) included 56.4% of the isolates. With the exception of ST11, all other STs were associated with a specific serogroup. Epidemic circulation of serogroup C ST8 isolates was detected in 1997-1998, as well as epidemic circulation of ST11 isolates (serogroups B and C) in 2002-2004. The epidemic behavior of serogroup B ST11 (ST11_B:2a:P1.5) was similar, although with lesser intensity, to that of ST11 of serogroup C. Although clonality increased during epidemic years, the overall diversity of the meningococcal population did not increase throughout the 12 years of the study.
The overall diversity of the meningococcal population, measured by the frequency of STs and clonal complexes, numbers of alleles, polymorphic sites, and index of association, remained relatively constant throughout the study period, contradicting previous findings by other researchers.
脑膜炎奈瑟菌由于其高重组率而迅速多样化。本研究旨在分析两次疫苗接种运动（1997 年对 18 个月至 20 岁人群进行的一次性 A/C 多糖疫苗接种运动，以及 2000 年至 2008 年对<或=6 岁儿童进行的脑膜炎球菌 C 结合疫苗接种运动）对 1997 年至 2008 年间获得的侵袭性分离株人群多样性的可能影响。包括所有 461 株可利用的分离株（分别属于血清群 A、B、C、Y 和 W-135 的 2、319、123、11 和 6 株）。
方法/主要发现：使用多位点序列分型、eBURST 和 S.T.A.R.T.2 程序对分离株进行多样性分析。获得了 107 个序列型（ST）和 20 个克隆复合体。有 5 个不同的 ST（ST11、ST8、ST33、ST1163 和 ST3496）包含了 56.4%的分离株。除 ST11 外，所有其他 ST 都与特定的血清群有关。1997-1998 年检测到血清群 C ST8 分离株的流行循环，2002-2004 年也检测到 ST11 分离株（血清群 B 和 C）的流行循环。血清群 B ST11（ST11_B:2a:P1.5）的流行行为与血清群 C 的 ST11 相似，尽管强度较小。尽管在流行年份的克隆性增加，但整个脑膜炎奈瑟菌人群的多样性在 12 年的研究期间并没有增加。
通过 ST 和克隆复合体的频率、等位基因数量、多态性位点和关联指数来衡量，整个脑膜炎奈瑟菌人群的多样性在整个研究期间相对保持不变，这与其他研究人员的先前发现相矛盾。
