Centre for Epidemiology and Microbiology, National Institute of Public Health, Prague, Czech Republic; Department of Clinical Microbiology, Faculty of Medicine and University Hospital, Charles University, Hradec Kralove, Czech Republic.
Centre for Epidemiology and Microbiology, National Institute of Public Health, Prague, Czech Republic.
J Microbiol Immunol Infect. 2020 Oct;53(5):690-695. doi: 10.1016/j.jmii.2019.03.007. Epub 2019 Apr 11.
The aim of this study was to evaluate the presence of pilus islet 1 (PI-1) and to determine its clade type in pneumococcal isolates with reduced susceptibility to penicillin (penicillin non-susceptible pneumococci - PNSP) and/or resistant to macrolides isolated prior to and after the introduction of pneumococcal conjugate vaccines (PCVs) in the Czech Republic.
Clinical isolates of serotypes 9V (n = 68) and 19A (n = 89) were examined. Isolates were characterised by multilocus sequence typing (MLST). The presence of PI-1 was determined by screening for the sortase B, C, and D genes located within PI-1. In the presence of PI-1 pilus, clade types were classified by PCR.
In the pre-PCV period (2000-2007), the prevalence of PNSP was 3.9% and 2.7% of isolates were resistant to erythromycin. During 2012-2015 (post-PCV period), the rates of PNSP remained stable (3.6%), but resistance to erythromycin increased to 8.3%. While in 2000-2007, resistance to antibiotics was associated mainly with serotype 9V, in 2012-2015, it was replaced by serotype 19A. PI-1 positive isolates were seen in both serotypes. All isolates (68) of serotype 9V belonged to the Spain-3 (CC156) clone and carried PI-1 of clade type I while 96.5% (56/58) of isolates of 19A serotype belonged to the Netherlands-37 (CC199) clone and carried PI-1 of clade type II.
Both major antibiotic resistant clones carried PI-1, although they differ in the clade type. Thus the role of PI-1 should be evaluated in further studies and potentially considered in the spread of antibiotic resistant clones.
本研究旨在评估青霉素不敏感肺炎球菌（PNSP）和/或对大环内酯类药物耐药的肺炎球菌分离株中存在的菌毛岛 1（PI-1），并确定其克隆类型，这些分离株在捷克共和国引入肺炎球菌结合疫苗（PCV）之前和之后分离得到。
检测了血清型 9V（n=68）和 19A（n=89）的临床分离株。通过多位点序列分型（MLST）对分离株进行鉴定。通过筛选位于 PI-1 内的种属酶 B、C 和 D 基因来确定 PI-1 的存在。在存在 PI-1 菌毛的情况下，通过 PCR 对克隆类型进行分类。
在 PCV 引入前（2000-2007 年），PNSP 的流行率为 3.9%，2.7%的分离株对红霉素耐药。在 2012-2015 年（PCV 引入后），PNSP 的发生率保持稳定（3.6%），但对红霉素的耐药性增加到 8.3%。2000-2007 年，抗生素耐药性主要与血清型 9V 相关，而在 2012-2015 年，它被血清型 19A 取代。两种血清型都存在 PI-1 阳性分离株。血清型 9V 的所有分离株（68 株）均属于西班牙 3 型（CC156）克隆，携带 I 型克隆类型的 PI-1，而 19A 血清型的 96.5%（56/58）分离株属于荷兰 37 型（CC199）克隆，携带 II 型克隆类型的 PI-1。
两种主要的抗生素耐药克隆都携带 PI-1，尽管它们在克隆类型上有所不同。因此，应在进一步的研究中评估 PI-1 的作用，并可能考虑其在抗生素耐药克隆传播中的作用。
