Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Building No. 7, 100 Poursina St., Keshavarz Blvd, Tehran, 14167-53955, Iran.
BMC Microbiol. 2020 Jun 16;20(1):167. doi: 10.1186/s12866-020-01855-y.
Streptococcus pneumoniae causes serious infections worldwide. The aim of this study was to determine the molecular characteristic, antibiotic resistance pattern and capsular types of invasive S. pneumoniae in Tehran, Iran.
Of the 44 pneumococcal invasive isolates, 39 (89%) were isolated from children and 5 (11%) from adults. The results show that all pneumococcal isolates were susceptible to linezolid but had varying resistance to trimethoprim-sulfamethoxazole (86%), erythromycin (73%), tetracycline (66%), clindamycin (43%), penicillin (16%), chloramphenicol (14%) and levofloxacin (2%). The range of erythromycin, tetracycline and penicillin MICs were 2 - ≥ 256 μg/mL, 4 - ≥ 48 μg/mL, and 0.047 - ≥ 256 respectively. All of the penicillin resistant isolates were multidrug resistant (MDR) and in addition to penicillin were resistant to tetracycline, erythromycin and trimethoprim-sulfamethoxazole. The most common capsular types detected in 64% of the pneumococcal isolates was 6A/B, 19A, 15A, 23F. The multilocus sequence typing (MLST) of 10 pneumococcal isolates revealed 9 different sequence types (STs), including ST 15139 (capsular type 19A) and ST 15140 (capsular type 23F), which have not previously been reported.
The study revealed that the S. pneumoniae isolates belonged to diverse capsular types and clones with high rate of resistance to erythromycin, tetracycline, and penicillin.
肺炎链球菌在全球范围内引起严重感染。本研究旨在确定伊朗德黑兰侵袭性肺炎链球菌的分子特征、抗生素耐药模式和荚膜型。
在 44 株肺炎链球菌侵袭性分离株中，39 株（89%）分离自儿童，5 株（11%）分离自成人。结果表明，所有肺炎链球菌分离株均对利奈唑胺敏感，但对甲氧苄啶-磺胺甲恶唑（86%）、红霉素（73%）、四环素（66%）、克林霉素（43%）、青霉素（16%）、氯霉素（14%）和左氧氟沙星（2%）的耐药性存在差异。红霉素、四环素和青霉素 MIC 的范围分别为 2-≥256μg/mL、4-≥48μg/mL 和 0.047-≥256。所有青霉素耐药分离株均为多重耐药（MDR），除对青霉素耐药外，还对四环素、红霉素和甲氧苄啶-磺胺甲恶唑耐药。在 64%的肺炎链球菌分离株中检测到最常见的荚膜型为 6A/B、19A、15A、23F。10 株肺炎链球菌的多位点序列分型（MLST）显示 9 种不同的序列型（ST），包括 ST15139（荚膜型 19A）和 ST15140（荚膜型 23F），这些 ST 此前尚未报道。
本研究表明，肺炎链球菌分离株属于多种荚膜型和克隆，对红霉素、四环素和青霉素的耐药率较高。
