Nazir Humera, Aziz Mubashar, Mirani Zulfiqar Ali, Sheikh Ahsan Sattar, Qamar Saeed Muhammad, Ahmed Khan Aleem, Ruby Tahira, Rauf Naseem
Department of Microbiology, Quaid-i-Azam University, Islamabad, Pakistan.
Institute of Pure and Applied Biology, (Microbiology division) Bahauddin Zakariya University, Multan 60900, Pakistan.
Iran J Basic Med Sci. 2021 Mar;24(3):400-407. doi: 10.22038/ijbms.2021.47095.10865.
Emergence of multidrug resistance has reduced the choice of antimicrobial regimens for UTIs. To understand the association of phenotype and genotype among uropathogens.
Six hundred and twenty-eight (628) urine samples were collected and analyzed. Antibiotic sensitivity pattern was determined by the Kirby-Bauer Disc Diffusion Method and minimum inhibitory concentration (MIC) was tested by the E test. Fluoroquinolone resistant mutations in QRDR of and , phylogenetic groups, and PAI subtype were detected by PCR.
Most prevalent uropathogens were (53.2%) followed by (21%). Multidrug- resistance was observed in > 50% cases for third-generation cephalosporins and ciprofloxacin and lowest in meropenem. (66.2%) and (64.4%) were extended-spectrum β-lactamases (ESBLs) producers. MIC to trimethoprim-sulfamethoxazole was highest in (>1024 µg/ml). In 80 (24%) of the 334 isolates analyzed in detail, 54 fluoroquinolones (FQ) resistant isolates carried mutations (S83L, D87N, S80I, E84V) in QRDR of and . Out of 54 FQ-resistant isolates, 43 (79.6%) isolates belonged to the phylogenetic group B2, and 11(20.4%) belonged to group D. Isolates belonged to group B2, 38 (88.4%) of the 43 isolates carried PAI subtype IIa and high frequency of mutation E84V in was detected in 37 (97.4%). Other mutations, such as S80I, S83L in and D87N in were found in all resistant isolates.
Correlations between phenotype and genotype provided a basis to understand the resistance development in uropathogens, and PAI subtyping indicated that belonged to the B2 group.
多重耐药性的出现减少了尿路感染抗菌治疗方案的选择。旨在了解尿路病原体表型与基因型之间的关联。
收集并分析了628份尿液样本。采用 Kirby-Bauer 纸片扩散法测定抗生素敏感性模式，用 E 试验检测最低抑菌浓度（MIC）。通过 PCR 检测gyrA和parC喹诺酮耐药决定区（QRDR）的氟喹诺酮耐药突变、系统发育群和PAI亚型。
最常见的尿路病原体是大肠埃希菌（53.2%），其次是肺炎克雷伯菌（21%）。超过50%的病例对第三代头孢菌素和环丙沙星呈现多重耐药，对美罗培南的耐药率最低。大肠埃希菌（66.2%）和肺炎克雷伯菌（64.4%）是超广谱β-内酰胺酶（ESBLs）产生菌。奇异变形杆菌对甲氧苄啶-磺胺甲恶唑的MIC最高（>1024μg/ml）。在详细分析的334株大肠埃希菌分离株中，80株（24%），54株氟喹诺酮（FQ）耐药分离株在gyrA和parC的QRDR中携带突变（S83L、D87N、S80I、E84V）。在54株FQ耐药分离株中，43株（79.6%）分离株属于系统发育群B2，11株（20.4%）属于群D。属于群B2的分离株，43株中的38株（88.4%）携带PAI亚型IIa，在37株（97.4%）中检测到gyrA中E84V突变的高频率。在所有耐药分离株中还发现了其他突变, 如gyrA中的S80I、S83L和parC中的D87N。
表型与基因型之间的相关性为了解尿路病原体耐药性发展提供了依据，PAI分型表明大肠埃希菌属于B2群。
