Infectious Diseases Research Center, Golestan University of Medical Science, Gorgan, Iran.
General Practitioner, Infectious Diseases Research Center, Golestan University of Medical Science, Gorgan, Iran.
Ethiop J Health Sci. 2021 May;31(3):663-672. doi: 10.4314/ejhs.v31i3.24.
This cross-sectional study was performed on isolates of Klebsiella pneumoniae, and E.coli from clinical specimens of patients admitted to Sayyad Shirazi Hospital by census sampling method in 2019. Antibiogram testing was performed using the disk diffusion method as defined by the Clinical and Laboratory Standards Organization for performing this test. Finally, the abundance of genes was evaluated by PCR using specific primers. Frequency, percentage, mean±SD were used to describe the data. Chi-square and Fisher's exact tests were used to compare the presence and absence of the studied genes alone and in the presence of each other.
This study was performed on 130 positive samples, isolated from 32 (24.6%) males and 98 (65.4%) females with a mean age of 43.78 ± 21.72. From the total number of 130 isolates, 84 (64.6%) consisted of E.coli, and 46 (35.4%) were Klebsiella. Most of the cultures were urine and vaginal (61.5%). The highest antibiotic resistance in isolates was cephalexin and cefazolin (67.9% in E.coli & 63% in Klebsiella). Colistin was identified as the most effective antibiotic (100%) in both. AMPC extendedspectrum β-lactamase genes were present in 40 (30.8%) isolates. The highest frequency about the gene pattern of AMPC positive β-lactamase bacteria was correlated to DHA, FOX, and CIT genes, while none of the samples contained the MOX β-lactamase gene. E.coli and Klebsiella beta-lactamase-producing AMPC isolates were also significantly correlated with antibiotic resistance to the cephalosporin class (P <0.05).
This study indicated a high percentage of resistance to third and fourth generation cephalosporins. Hence, careful antibiogram tests and prevention of antibiotic overuse in infections caused by AMPC-producing organisms and screening of clinical samples for the resistance mentioned above genes and providing effective strategies to help diagnose and apply appropriate treatments and change antibiotic usage strategies can partially prevent the transmission of this resistance.
本横断面研究采用整群抽样法，于 2019 年从收治于 Sayyad Shirazi 医院的患者临床标本中分离出肺炎克雷伯菌和大肠杆菌的临床分离株。药敏试验采用临床和实验室标准协会（CLSI）定义的纸片扩散法进行。最后，采用特异性引物通过 PCR 评估基因丰度。使用频率、百分比、均数±标准差描述数据。采用卡方检验和 Fisher 确切概率法比较研究基因单独存在和相互存在时的存在情况。
本研究共纳入 130 例阳性样本，分离自 32 例（24.6%）男性和 98 例（65.4%）女性，平均年龄为 43.78±21.72 岁。在总共 130 例分离株中，84 株（64.6%）为大肠杆菌，46 株（35.4%）为肺炎克雷伯菌。大多数培养物为尿液和阴道标本（61.5%）。分离株中抗生素耐药性最高的是头孢氨苄和头孢唑林（大肠杆菌中耐药率为 67.9%，肺炎克雷伯菌中耐药率为 63%）。多粘菌素被鉴定为两种细菌中最有效的抗生素（100%）。在 40 株（30.8%）分离株中存在 AMPC 型扩展谱β-内酰胺酶基因。AMP 阳性β-内酰胺酶细菌的基因模式中，DHA、FOX 和 CIT 基因的频率最高，而没有样本含有 MOX 型β-内酰胺酶基因。产 AMPC 型β-内酰胺酶的大肠杆菌和肺炎克雷伯菌与头孢菌素类抗生素耐药性显著相关（P<0.05）。
本研究表明，第三代和第四代头孢菌素的耐药率较高。因此，在由产 AMPC 型酶的病原体引起的感染中，应仔细进行药敏试验和避免抗生素过度使用，并对上述耐药基因的临床样本进行筛查，制定有效的策略来帮助诊断并应用适当的治疗方法，改变抗生素使用策略，这在一定程度上可以预防这种耐药性的传播。
