Santona Simona, Diaz Nicia, Fiori Pier Luigi, Francisco Moises, Sidat Mohsin, Cappuccinelli Piero, Rappelli Paola
Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
J Infect Dev Ctries. 2013 Mar 14;7(3):214-9. doi: 10.3855/jidc.3054.
Typical EPEC are considered a leading cause of diarrhoea in developing countries, while atypical EPEC have been isolated more frequently in developed areas. The actual geographic distribution of the two EPEC subgroups is controversial, since data can be highly influenced by laboratory resources. This study aimed to compare the distribution of typical and atypical EPEC among children in developed and developing countries, and to characterize the bacterial isolates, using a unique methodological approach.
A total of 1,049 E. coli were isolated from faeces of children with acute diarrhoea in Mozambique, Angola and Italy, and processed by PCR to assess the presence of a large panel of virulence genes. All isolates classified as EPEC were further characterized by evaluating adherence and capability to induce actin rearrangement on Hep-2 cells.
Overall we isolated 59 EPEC, likewise distributed in the three countries, representing the 5.04%, 4.44% and 6.97% of all Mozambican, Angolan and Italian isolates, respectively. Nevertheless, the geographic distribution of the two EPEC subgroups was not homogeneous: in Italy we isolated 28 aEPEC but no tEPEC, while in Angola and Mozambique the percentage of the two subgroups was comparable. Twelve atypical EPEC were FAS positive and able to induce localized-like adherence on Hep-2 cells, but no correlation with the geographic origin of isolates was observed.
Atypical EPEC are present in sub-Saharan areas in a percentage similar to that of typical strains, and are not mainly restricted to industrialized countries, as it was previously supposed.
典型肠致病性大肠杆菌（EPEC）被认为是发展中国家腹泻的主要病因，而非典型EPEC在发达地区的分离频率更高。这两种EPEC亚群的实际地理分布存在争议，因为数据可能受到实验室资源的高度影响。本研究旨在采用独特的方法，比较典型和非典型EPEC在发达国家和发展中国家儿童中的分布，并对细菌分离株进行特征分析。
从莫桑比克、安哥拉和意大利患有急性腹泻儿童的粪便中总共分离出1049株大肠杆菌，并通过聚合酶链反应（PCR）进行处理，以评估大量毒力基因的存在情况。所有被归类为EPEC的分离株通过评估其在Hep-2细胞上的黏附情况和诱导肌动蛋白重排的能力进行进一步特征分析。
总体而言，我们分离出59株EPEC，在三个国家中的分布相似，分别占莫桑比克、安哥拉和意大利所有分离株的5.04%、4.44%和6.97%。然而，这两种EPEC亚群的地理分布并不均匀：在意大利我们分离出28株非典型EPEC，但没有典型EPEC，而在安哥拉和莫桑比克，这两个亚群的百分比相当。12株非典型EPEC FAS呈阳性，能够在Hep-2细胞上诱导局部样黏附，但未观察到与分离株地理来源的相关性。
非典型EPEC在撒哈拉以南地区的比例与典型菌株相似，并不像之前所认为的那样主要局限于工业化国家。
