Singh Taru, Das Shukla, Ramachandran V G, Wani Sayim, Shah Dheeraj, Maroof Khan A, Sharma Aditi
Microbiology, University College of Medical Sciences and Guru Teg Bahadur HospitalNew Delhi, India.
Dermatology, University College of Medical Sciences and Guru Teg Bahadur Hospital, Dilshad GardenNew Delhi, India.
Front Microbiol. 2017 Apr 10;8:561. doi: 10.3389/fmicb.2017.00561. eCollection 2017.
Integrons by means of horizontal gene transfer carry multidrug resistance genes (MDR) among bacteria, including . The aim of this study was to determine the antibiotic resistance profiles and the genes associated with them, to gain insights in the distribution of phylogroups, prevalence, and characterization of class 1, 2 and 3 integrons among Enteropathogenic (EPEC) isolates, from children upto 5 years of age from Delhi and National Capital Region (NCR), India. A total of 120 isolates, including 80 from diarrheagenic (cases) and 40 from healthy isolates (controls) were recruited in this study. After isolation of , screening for EPEC was done by conventional multiplex PCR. Antibiotic suseptibility test was performed using disk diffusion method and further confirmed by minimum inhibitory concentration (MICs) by -test. The presence and characterization of integrons and antimicrobial resistance genes were performed by PCR and DNA sequencing. Phylogeny determination was carried out by quadruplex PCR. EPEC strains were found in 64 of the 80 diarrheagenic cases, out of which 38 were MDR. In the 40 healthy controls, 23 were found to be EPEC strain, out of which only 2 were MDR. Amongst 80 diarrheagenic cases, class 1 integron were observed in 43 isolates, class 2 integron in 12 isolates and 9 isolates were found with co-existence of both. Similarly, in healthy controls; class 1 integron in 9 and class 2 integron in 7 isolates were observed with co-existence in 3 isolates. None of the isolates included class 3 integron. The was the most commonly identified gene cassette within the integron-positive isolates. Phylogenetic studies showed considerable representation of phylogroup B2 in both diarrheagenic cases and healthy controls. This study reiterates the importance of class 1 integron predominantly for acquisition of antibiotic resistance genes among EPEC isolates. Furthermore, it also ascertains the possible association between multidrug resistance and presence of integrons. Approximately 91% of isolates were easily assigned to their respective phylogroups. Assessment of the relationship between antibiotic resistance and dominant phylogroups detected was also attempted. This study also highlights the increased burden of antimicrobial resistance in healthy controls.
整合子通过水平基因转移在细菌间携带多重耐药基因（MDR），包括……本研究的目的是确定抗生素耐药谱及其相关基因，以深入了解印度德里及国家首都辖区（NCR）5岁以下儿童肠道致病性大肠杆菌（EPEC）分离株中1类、2类和3类整合子的菌群分布、流行情况及特征。本研究共招募了120株分离株，其中80株来自腹泻性大肠杆菌（病例组），40株来自健康分离株（对照组）。分离出大肠杆菌后，通过传统多重PCR筛选EPEC。采用纸片扩散法进行抗生素敏感性试验，并通过肉汤稀释法测定最低抑菌浓度（MIC）进一步确认。通过PCR和DNA测序确定整合子和抗菌耐药基因的存在及特征。通过四重PCR进行系统发育测定。在80例腹泻病例中，64例发现有EPEC菌株，其中38例为多重耐药菌株。在40例健康对照中，23例发现为EPEC菌株，其中仅2例为多重耐药菌株。在80例腹泻病例中，43株分离株检测到1类整合子，12株检测到2类整合子，9株同时存在1类和2类整合子。同样，在健康对照中，9株检测到1类整合子，7株检测到2类整合子，3株同时存在这两类整合子。所有分离株均未检测到3类整合子。整合子阳性分离株中最常鉴定出的基因盒是……系统发育研究表明，菌群B2在腹泻病例组和健康对照组中均有相当比例。本研究重申了1类整合子在EPEC分离株中获取抗生素耐药基因方面的重要性。此外，还确定了多重耐药与整合子存在之间的可能关联。约91%的分离株能够容易地归为各自的菌群。还尝试评估检测到的抗生素耐药性与优势菌群之间的关系。本研究还突出了健康对照中抗菌耐药负担的增加。
