志贺氏菌物种由于其在腹泻疾病中的作用而对全球健康产生重大影响。2019-2022年对马什哈德儿科患者432份粪便样本进行的横断面研究,伊朗,鉴定了志贺氏菌属。并通过圆盘扩散法测试了它们对12种抗菌剂的敏感性。毒力因子的存在,即ipaH,virA,stx1和stx2,以及质粒介导的喹诺酮耐药(PMQR)基因,包括qnrA,qnrB,qnrC,qnrD,和qnrS,是通过利用聚合酶链反应技术确定的。对gyrA和parC基因的喹诺酮耐药决定区(QRDR)内检测到的15个分离株进行测序,表明氟喹诺酮(FQ)耐药。19.2%(83/432)的粪便样本含有志贺氏菌,主要是S.sonnei(77.1%),其次是福尔内尼(21.6%)和博伊迪(1.2%)。大多数分离株来自5岁以下儿童(55.4%)。所有菌株都有ipaH基因,缺少stx1和stx2,86.7%有virA。氨苄青霉素和四环素的耐药性较高(各84.3%),甲氧苄啶-磺胺甲恶唑(81.9%),和阿奇霉素(60.2%)。87.1%的分离株为多重耐药(MDR)。最常见的PMQR基因是qnrA和qnrS(各41%)。qnrD基因,在36.1%的病例中普遍存在,这是伊朗首次报道。最常见的PMQR谱是qnrADS(15.7%)。对萘啶酸和环丙沙星的耐药率分别为45.8%和12%,分别。志贺氏菌分离株在gyrA(密码子83、87和211)和parC(密码子80、84、93、126、128、129和132)基因中显示出突变。志贺氏菌分离株中gyrA基因的D87Y突变最为常见,发生在73%的病例中。parC基因中的F93S和L132T突变是本研究特有的。MDR志贺氏菌感染患者的经验性FQ治疗,在gyrA和parC的QRDR中拥有PMQR决定簇和/或突变,可能会增加继发疾病的风险,延长治疗持续时间,治疗失败,和阻力蔓延。因此,持续监测和基因检测以检测耐FQ志贺氏菌菌株的必要性至关重要.
Shigella species significantly impact global health due to their role in diarrheal diseases. A 2019-2022 cross-sectional study on 432 stool samples from pediatric patients in Mashhad, Iran, identified Shigella spp. and tested their susceptibility to 12 antimicrobials by the disk diffusion method. The presence of virulence factors, namely ipaH, virA, stx1, and stx2, as well as plasmid-mediated quinolone resistance (PMQR) genes, including qnrA, qnrB, qnrC, qnrD, and qnrS, were ascertained through the utilization of polymerase chain reaction techniques. Sequencing of 15 isolates detected mutations within quinolone resistance-determining regions (QRDRs) at the gyrA and parC genes, indicating fluoroquinolone (FQ) resistance. 19.2 % (83/432) of stool samples contained Shigella, primarily S. sonnei (77.1 %), followed by S. flexneri (21.6 %) and S. boydii (1.2 %). Most isolates were from children under five (55.4 %). All strains had the ipaH gene, lacked stx1 and stx2, and 86.7 % had virA. High resistance was noted for ampicillin and tetracycline (84.3 % each), trimethoprim-sulfamethoxazole (81.9 %), and azithromycin (60.2 %). 87.1 % of isolates were multidrug-resistant (MDR). The most common PMQR genes were qnrA and qnrS (41 % each). The qnrD gene, prevalent in 36.1 % of cases, is reported in Iran for the first time. The most common PMQR profile was qnrADS (15.7 %). Resistance to nalidixic acid and ciprofloxacin was 45.8 % and 12 %, respectively. The Shigella isolates exhibited mutations in the gyrA (at codons 83, 87, and 211) and parC (at codons 80, 84, 93, 126, 128, 129, and 132) genes. The D87Y mutation in the gyrA gene was the most common in Shigella isolates, occurring in 73 % of cases. The F93S and L132T mutations in the parC gene were unique to this study. Empirical FQ therapy in patients infected with MDR Shigella, possessing PMQR determinants and/or mutations in the QRDRs of gyrA and parC, may escalate the risks of secondary diseases, extended treatment duration, therapeutic failure, and resistance spread. Consequently, the necessity for continuous surveillance and genetic testing to detect FQ-resistant Shigella strains is of paramount importance.