Fahmy H M, El-Serougi A O, El Deeb H K, Hussein H M, Abou-Seri H M, Klotz C, Aebischer T, El Sayed Khalifa Mohamed K
Faculty of Medicine, Ain Shams University, 11566, Cairo, Egypt.
Eur J Clin Microbiol Infect Dis. 2015 Aug;34(8):1573-81. doi: 10.1007/s10096-015-2389-7. Epub 2015 May 5.
Giardia duodenalis is considered the most common cause of parasitic diarrhea worldwide. Genetic studies revealed that at least eight assemblages (A-H) exist. Of these assemblages, A and B are found primarily in human beings and occasionally in animals. The association between clinical symptoms and G. duodenalis assemblages is controversial. The aim of the present study was to determine the assemblages of G. duodenalis prevalent among Egyptian children with diarrhea. Therefore, 96 positive stool samples for Giardia by light microscopy were subjected to multilocus genotyping targeting the triose phosphate isomerase (tpi), β-giardin (bg), and glutamate dehydrogenase (gdh) genes. Amplified polymerase chain reaction (PCR) products were then purified, sequenced, and aligned with reference strains to determine the assemblages of the Giardia isolates. Out of the 96 microscopically positive stool samples for Giardia, 77 (80 %) were successfully amplified and sequenced at least at one locus. Of these, 21 (27.3 %) were shown to be assemblage A, 54 (70.1 %) assemblage B, while discordant sequence typing results were observed in 2 (2.6 %) samples. AII was the predominant subassemblage of assemblage A, while it was generally difficult to further classify assemblage B. It was concluded that infection with assemblage B was more common than that with assemblage A. No associations between epidemiological information and assemblage were detected, except with age. Although infections with assemblage B were more frequently associated with abdominal pain and acute diarrhea than with assemblage A, the difference was not statistically significant.
十二指肠贾第虫被认为是全球寄生性腹泻最常见的病因。基因研究表明，至少存在八个基因组合（A - H）。在这些基因组合中，A和B主要存在于人类中，偶尔也见于动物。临床症状与十二指肠贾第虫基因组合之间的关联存在争议。本研究的目的是确定埃及腹泻儿童中流行的十二指肠贾第虫基因组合。因此，对96份经光学显微镜检查为贾第虫阳性的粪便样本进行多位点基因分型，靶向磷酸丙糖异构酶（tpi）、β - 贾第蛋白（bg）和谷氨酸脱氢酶（gdh）基因。然后对扩增的聚合酶链反应（PCR）产物进行纯化、测序，并与参考菌株比对，以确定贾第虫分离株的基因组合。在96份经显微镜检查为贾第虫阳性的粪便样本中，77份（80%）至少在一个位点成功扩增并测序。其中，21份（27.3%）显示为A组合，54份（70.1%）为B组合，而在2份（2.6%）样本中观察到不一致的序列分型结果。AII是A组合的主要亚组合，而B组合通常难以进一步分类。得出的结论是，B组合感染比A组合更常见。除年龄外，未检测到流行病学信息与基因组合之间的关联。尽管B组合感染比A组合更常与腹痛和急性腹泻相关，但差异无统计学意义。
