Calderaro Adriana, Buttrini Mirko, Martinelli Monica, Farina Benedetta, Moro Tiziano, Montecchini Sara, Arcangeletti Maria Cristina, Chezzi Carlo, De Conto Flora
Department of Medicine and Surgery, University of Parma, Viale A. Gramsci 14, 43126 Parma, Italy.
Unit of Clinical Microbiology, University Hospital of Parma, Viale A. Gramsci 14, 43126 Parma, Italy.
Microorganisms. 2021 Mar 23;9(3):661. doi: 10.3390/microorganisms9030661.
Typing methods are needed for epidemiological tracking of new emerging and hypervirulent strains because of the growing incidence, severity and mortality of infections (CDI). The aim of this study was the evaluation of a typing Matrix-Assisted Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS (T-MALDI)) method for the rapid classification of the circulating strains in comparison with polymerase chain reaction (PCR)-ribotyping results. Among 95 strains, 10 ribotypes (PR1-PR10) were identified by PCR-ribotyping. In particular, 93.7% of the isolates (89/95) were grouped in five ribotypes (PR1-PR5). For T-MALDI, two classifying algorithm models (CAM) were tested: the first CAM involved all 10 ribotypes whereas the second one only the PR1-PR5 ribotypes. Better performance was obtained using the second CAM: recognition capability of 100%, cross-validation of 96.6% and agreement of 98.4% (60 correctly typed strains, limited to PR1-PR5 classification, out of 61 examined strains) with PCR-ribotyping results. T-MALDI seems to represent an alternative to PCR-ribotyping in terms of reproducibility, set up time and costs, as well as a useful tool in epidemiological investigation for the detection of clusters (either among CAM included ribotypes or out-of-CAM ribotypes) involved in outbreaks.
由于艰难梭菌感染（CDI）的发病率、严重程度和死亡率不断上升，需要采用分型方法对新出现的高毒力菌株进行流行病学追踪。本研究的目的是评估一种基于基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS，T-MALDI）的分型方法，以便与聚合酶链反应（PCR）核糖体分型结果相比较，对流行菌株进行快速分类。在95株菌株中，通过PCR核糖体分型鉴定出10种核糖体分型（PR1-PR10）。特别是，93.7%的分离株（89/95）被归为五种核糖体分型（PR1-PR5）。对于T-MALDI，测试了两种分类算法模型（CAM）：第一种CAM涉及所有10种核糖体分型，而第二种仅涉及PR1-PR5核糖体分型。使用第二种CAM获得了更好的性能：识别能力为100%，交叉验证为96.6%，与PCR核糖体分型结果的一致性为98.4%（在61株检测菌株中，60株分型正确，仅限于PR1-PR5分类）。在可重复性、设置时间和成本方面，T-MALDI似乎是PCR核糖体分型的一种替代方法，也是流行病学调查中检测暴发中涉及的聚集性病例（无论是CAM包含的核糖体分型还是CAM外的核糖体分型）的有用工具。
