Zhou J, Enright M C, Spratt B G
Wellcome Trust Centre for the Epidemiology of Infectious Disease, Department of Zoology, University of Oxford, Oxford OX1 3FY, United Kingdom.
J Clin Microbiol. 2000 Mar;38(3):977-86. doi: 10.1128/JCM.38.3.977-986.2000.
Multilocus sequence typing was used to characterize isolates of the major Spanish clones of penicillin-resistant and multiple-antibiotic-resistant Streptococcus pneumoniae. Isolates of the multidrug-resistant Spanish serotype 23F clone and serotype variants of this clone either had identical allelic profiles or their allelic profiles differed from this typical allelic profile at only one of the seven housekeeping loci. Similarly, isolates of the Spanish serotype 6B and 14 clones and the penicillin-resistant serotype 9V clone (and serotype variants of this clone) each had the same allelic profiles or profiles that differed at a single locus. Multilocus sequence typing therefore allows resistant pneumococci to be assigned to the Spanish clones if they have the typical allelic profile of the clone or if their profiles differ from that profile at a single locus. A few resistant isolates that had allelic profiles typical of that of a Spanish clone or whose profiles differed from that of the typical profile at only a single locus possessed penicillin-binding protein pbp1a, pbp2b, or pbp2x genes that differed from those that are characteristic of the clone. In most cases these isolates could be assigned as variant members of the clone. Since almost all serotype 9V isolates have very similar genotypes, independently emerging penicillin-resistant clones of this serotype will inevitably appear to be similar by molecular typing procedures. Analysis of the pbp genes, in addition to multilocus sequence typing (or any other molecular typing procedure), is therefore required to assign isolates unambiguously to the penicillin-resistant Spanish serotype 9V clone.
多位点序列分型用于鉴定西班牙主要的耐青霉素和多重耐药肺炎链球菌克隆的分离株。多重耐药的西班牙血清型23F克隆及其血清型变异株的分离株，要么具有相同的等位基因谱，要么其等位基因谱与该典型等位基因谱相比，在7个管家基因座中只有1个不同。同样，西班牙血清型6B和14克隆以及耐青霉素血清型9V克隆（及其血清型变异株）的分离株，各自具有相同的等位基因谱，或者仅在一个基因座上不同的谱型。因此，如果耐药肺炎球菌具有克隆的典型等位基因谱，或者其谱型与该谱型相比仅在一个基因座上不同，那么多位点序列分型可将它们归为西班牙克隆。少数具有西班牙克隆典型等位基因谱或其谱型仅在一个基因座上与典型谱型不同的耐药分离株，具有与该克隆特征不同的青霉素结合蛋白pbp1a、pbp2b或pbp2x基因。在大多数情况下，这些分离株可被归为该克隆的变异成员。由于几乎所有血清型9V分离株都具有非常相似的基因型，通过分子分型程序，该血清型独立出现的耐青霉素克隆将不可避免地显得相似。因此，除了多位点序列分型（或任何其他分子分型程序）外，还需要分析pbp基因，以便将分离株明确归为耐青霉素的西班牙血清型9V克隆。
