Clinical Microbiology, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden.
Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark.
Front Cell Infect Microbiol. 2022 Mar 22;12:824449. doi: 10.3389/fcimb.2022.824449. eCollection 2022.
BACKGROUND/OBJECTIVE: The frequencies of non-susceptibility against common antibiotics among pneumococci vary greatly across the globe. When compared to other European countries antibiotic resistance against penicillin and macrolides has been uncommon in Sweden in recent years. Multidrug resistance (MDR) is, however, of high importance since relevant treatment options are scarce. The purpose of this study was to characterize the molecular epidemiology, presence of resistance genes and selected virulence genes of extensively drug-resistant (XDR) (=15) and MDR (=10) detected in clinical respiratory tract samples isolated from patients in a southern Swedish county 2016-2018. With the aim of relating them to global MDR pneumococci.
Whole genome sequencing (WGS) was performed to determine molecular epidemiology, resistance genes and presence of selected virulence factors. Antimicrobial susceptibility profiles were determined using broth microdilution testing. Further analyses were performed on isolates from the study and from the European nucleotide archive belonging to global pneumococcal sequence cluster (GPSC) 1 (86), GPSC9 (55) and GPSC10 (57). Bacteria were analyzed regarding selected virulence determinants (pilus islet 1, pilus islet 2 and Zinc metalloproteinase C) and resistance genes.
Nineteen of 25 isolates were related to dominant global MDR lineages. Seventeen belonged to GPSC1, GPSC9 or GPSC10 with MDR non-PCV serotypes in GPSC9 (serotype 15A and 15C) as well as GPSC10 (serotype 7B, 15B and serogroup 24). Pilus islet-1 and pilus islet-2 were present in most sequence types belonging to GPSC1 and in two isolates within GPSC9 but were not detected in isolates belonging to GPSC10. Zinc metalloproteinase C was well conserved within all analyzed isolates belonging to GPSC9 but were not found in isolates from GPSC1 or GPSC10.
Although MDR is relatively uncommon in Sweden compared to other countries, virulent non-PCV serotypes that are MDR may become an increasing problem, particularly from clusters GPSC9 and GPSC10. Since the incidence of certain serotypes (3, 15A, and 19A) found among our MDR Swedish study isolates are persistent or increasing in invasive pneumococcal disease further surveillance is warranted.
背景/目的：世界各地肺炎球菌对常见抗生素的非敏感性频率差异很大。与其他欧洲国家相比，近年来瑞典对青霉素和大环内酯类抗生素的耐药性并不常见。然而，由于相关治疗选择稀缺，多药耐药性（MDR）非常重要。本研究的目的是描述 2016-2018 年从瑞典南部一个县的临床呼吸道样本中分离出的 15 株广泛耐药（XDR）=15 和 10 株 MDR=10 的肺炎球菌的分子流行病学、耐药基因和选定毒力基因的特征，以将其与全球 MDR 肺炎球菌进行比较。
采用全基因组测序（WGS）确定分子流行病学、耐药基因和选定毒力因子的存在。使用肉汤微量稀释法测定抗菌药物敏感性谱。对来自研究的分离株和来自欧洲核苷酸档案的属于全球肺炎球菌序列群（GPSC）1（86）、GPSC9（55）和 GPSC10（57）的分离株进行了进一步分析。对选定的毒力决定因素（菌毛岛 1、菌毛岛 2 和锌金属蛋白酶 C）和耐药基因进行了细菌分析。
25 株分离株中有 19 株与主要的全球 MDR 谱系有关。17 株属于 GPSC1、GPSC9 或 GPSC10，GPSC9 中存在 MDR 非 PCV 血清型（血清型 15A 和 15C）和 GPSC10（血清型 7B、15B 和血清组 24）。菌毛岛 1 和菌毛岛 2 存在于大多数属于 GPSC1 的序列型和 GPSC9 中的两个分离株中，但在属于 GPSC10 的分离株中未检测到。锌金属蛋白酶 C在所有分析的属于 GPSC9 的分离株中都得到了很好的保守，但在属于 GPSC1 或 GPSC10 的分离株中没有发现。
尽管与其他国家相比，瑞典的 MDR 相对较少，但可能成为一个日益严重的问题，特别是来自 GPSC9 和 GPSC10 的毒力非 PCV 血清型 MDR。由于我们的瑞典 MDR 研究分离株中发现的某些血清型（3、15A 和 19A）的发病率在侵袭性肺炎球菌病中持续或增加，因此需要进一步监测。
