College of Biotechnology, Al-Qasim Green University, Babylon Province, Iraq.
Collage of Medicine, Microbiological Department, University of Babylon Province, Iraq.
Arch Razi Inst. 2021 Sep 1;76(3):561-573. doi: 10.22092/ari.2021.355392.1679. eCollection 2021 Summer.
Quinolone antimicrobials are widely used in clinical medicine due to their wide spectrum with high tissue penetration and ease of use; but increasing resistance with clinical use appears to be common in some bacterial pathogens, including Escherichia coli (). The aim of this study was to investigate plasmid-mediated quinolone resistance determinants (PMQR) including, A, B, and S as the emerging mechanisms of quinolone resistance of isolates from different clinical sites in Karbala province, Iraq. A total of 200 clinical samples were collected from patients suffering from infections such as UTI, gastro enteritis (diarrhea), vaginitis, and wound infections; 30 samples were diagnosed as clinical strain from both sexes and different ages after identification by biochemical test, VITEK-2 compact system, and by molecular method using 16Sr DNA marker. Antimicrobial susceptibility and minimal inhibition concentration (MIC) testing for nalidixic acid, norfloxacin, ciprofloxacin, levofloxacin, and gatifloxacin was performed using the broth microdilution method. All strains were screened for PMQR genes A, B, and S by the PCR method after DNA extraction from tested clinical isolates of . The results showed that is largely isolated from vaginal (40%) and urine (32%) samples, followed by wound infections (24%) and stools (21%).The high occurrence rate of (33.33%) isolates was observed in participants aged 31-45 years, while a lower occurrence (10%)was recorded in a group of ˃ 60-year-old female participants. Females have a notably increased frequency of compared to males, with the female to male ratio being 87%: 13%. Molecular investigation showed the total percentage of isolates harboring genes to be 21/30 (70%); this figure is composed of 14/30 isolates harboring in combined or mixed form (46.66%) and 7/30 (23.33%) isolates harboring in single form (3 isolates harboring A alone, 1 isolate harboring B alone, 3 isolates harboring S alone).The prevalence rates of A, B, and S were 40%, 43.33%, and 53.33%, respectively. The results also showed that among isolates encoding genes A, B, and S, 24%, 12%, and 36% were resistant to nalidixic acid, respectively. Among those isolates carrying A, B, and S genes, 15.8%, 5.3%, and 26.3%, respectively, were resistant to ciprofloxacin. Moreover, Norfloxacin resistance was seen in 20.0%, 5.0%, and 30.0% of isolates harboring A, B, and S genes, respectively. Levofloxacin resistance was seen in 37.5%, 75.0%, and 37.5% of the isolates carrying the A, B, and S genes, respectively. The lowest resistance rates of A, B, and S-positive strains were against gatifloxacin (0,0, and 25%, respectively).A high prevalence of genes enhances the increasing resistance rate of against the quinolone antibiotic under study.
喹诺酮类抗菌药物由于其广泛的谱、高组织穿透性和易用性而在临床医学中广泛应用；但在一些细菌病原体中，包括大肠杆菌（），临床使用后出现的耐药性似乎很常见。本研究旨在调查质粒介导的喹诺酮类耐药决定因素（PMQR），包括 A、B 和 S，作为来自伊拉克卡尔巴拉省不同临床部位的 分离株对喹诺酮类药物耐药的新兴机制。共收集了 200 份来自尿路感染（UTI）、胃肠炎（腹泻）、阴道炎和伤口感染等感染患者的临床样本；从不同性别和不同年龄的患者中鉴定出 30 份临床株，鉴定方法为生化试验、VITEK-2 紧凑型系统和 16Sr DNA 标记物的分子方法。使用肉汤微量稀释法进行萘啶酸、诺氟沙星、环丙沙星、左氧氟沙星和加替沙星的药敏试验和最小抑菌浓度（MIC）检测。从 测试临床分离株中提取 DNA 后，用 PCR 法筛选 PMQR 基因 A、B 和 S。结果表明， 主要从阴道（40%）和尿液（32%）样本中分离，其次是伤口感染（24%）和粪便（21%）。在 31-45 岁的参与者中观察到 （33.33%）分离株的高发生率，而在一组年龄大于 60 岁的女性参与者中记录到较低的发生率（10%）。与男性相比，女性 的发生率明显增加，女性与男性的比例为 87%：13%。分子调查显示，携带 基因的 分离株总检出率为 21/30（70%）；这一数字由 14/30 株（46.66%）以组合或混合形式携带 和 7/30 株（23.33%）以单一形式携带 组成（3 株携带 A 单独，1 株携带 B 单独，3 株携带 S 单独）。A、B 和 S 的检出率分别为 40%、43.33%和 53.33%。结果还表明，在携带 基因 A、B 和 S 的 分离株中，分别有 24%、12%和 36%对萘啶酸耐药。在携带 A、B 和 S 基因的 分离株中，分别有 15.8%、5.3%和 26.3%对环丙沙星耐药。此外，携带 A、B 和 S 基因的 分离株对诺氟沙星的耐药率分别为 20.0%、5.0%和 30.0%。左氧氟沙星耐药分别见于携带 A、B 和 S 基因的 分离株的 37.5%、75.0%和 37.5%。A、B 和 S 阳性 株对加替沙星的最低耐药率分别为 0、0 和 25%。 基因的高检出率增加了 对研究中喹诺酮类抗生素的耐药率。
