Department of Microbiology, University of Tartu, Ravila 19, 50411 Tartu, Estonia.
Ann Clin Microbiol Antimicrob. 2009 Dec 8;8:34. doi: 10.1186/1476-0711-8-34.
The aim of our study was to compare the presence of the intI1 gene and its associations with the antibiotic resistance of commensal Escherichia coli strains in children with/without previous antibiotic treatments and elderly hospitalized/healthy individuals.
One-hundred-and-fifteen intestinal E. coli strains were analyzed: 30 strains from 10 antibiotic-naive infants; 27 from 9 antibiotic-treated outpatient infants; 30 from 9 healthy elderly volunteers; and 28 from 9 hospitalized elderly patients. The MIC values of ampicillin, cefuroxime, cefotaxime, gentamicin, ciprofloxacin, and sulfamethoxazole were measured by E-test and IntI1 was detected by PCR.
Out of the 115 strains, 56 (49%) carried class 1 integron genes. Comparing persons without medical interventions, we found in antibiotic-naive children a significantly higher frequency of integron-bearing strains and MIC values than in healthy elderly persons (53% versus 17%; p < 0.01). Evaluating medical interventions, we found a higher resistance and frequency of integrons in strains from hospitalized elderly persons compared with non-hospitalized ones. Children treated with antibiotics had strains with higher MIC values (when compared with antibiotic-naive ones), but the integron-bearing in strains was similar. In most cases, the differences in resistance between the groups (integron-positive and negative strains separately) were higher than the differences between integron-positive and negative strains within the groups.
The prevalence of integrons in commensal E. coli strains in persons without previous medical intervention depended on age. The resistance of integron-carrying and non-carrying strains is more dependent on influencing factors (hospitalization and antibiotic administration) in particular groups than merely the presence or absence of integrons.
本研究旨在比较携带 intI1 基因的共生大肠杆菌菌株在有/无既往抗生素治疗的儿童和住院/健康老年人中的存在情况及其与抗生素耐药性的关系。
分析了 115 株肠道大肠杆菌菌株：30 株来自 10 例抗生素未治疗的婴儿；27 株来自 9 例门诊抗生素治疗的婴儿；30 株来自 9 例健康老年志愿者；28 株来自 9 例住院老年患者。采用 E 试验法测定氨苄西林、头孢呋辛、头孢噻肟、庆大霉素、环丙沙星和磺胺甲噁唑的 MIC 值，采用 PCR 法检测 IntI1。
在 115 株菌株中，56 株（49%）携带 1 类整合子基因。与未接受医学干预的人群相比，在抗生素未治疗的儿童中，携带整合子的菌株和 MIC 值的频率明显高于健康老年人（53%比 17%；p<0.01）。评估医学干预，我们发现住院老年患者的菌株比非住院患者的菌株具有更高的耐药性和整合子频率。接受抗生素治疗的儿童的菌株具有更高的 MIC 值（与抗生素未治疗的菌株相比），但携带整合子的菌株则相似。在大多数情况下，各组之间（整合子阳性和阴性菌株分别）的耐药差异大于组内整合子阳性和阴性菌株之间的差异。
在无既往医疗干预的人群中，共生大肠杆菌菌株中整合子的流行率取决于年龄。整合子携带和非携带菌株的耐药性更多地取决于特定人群中的影响因素（住院和抗生素使用），而不仅仅是整合子的存在与否。
Zotero 插件