Atrisco-Morales Josefina, Martínez-Santos Verónica I, Román-Román Adolfo, Alarcón-Millán Judit, De Sampedro-Reyes José, Cruz-Del Carmen Iván, Martínez-Carrillo Dinorah N, Fernández-Tilapa Gloria
Laboratorio de Investigación Clínica, Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Guerrero, Av. Lázaro Cárdenas s/n C.U. Sur. Chilpancingo, Guerrero, C.P. 39090, Mexico.
CONACYT Research Fellow- Universidad Autónoma de Guerrero, Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Guerrero, Guerrero, Mexico.
J Med Microbiol. 2018 Mar;67(3):314-324. doi: 10.1099/jmm.0.000660. Epub 2018 Jan 10.
Virulent genotypes of Helicobacter pylori vacA s1m1/cagA/babA2 have been associated with severe gastric diseases. VacA, CagA and BabA are polymorphic proteins, and their association with the disease is allele-dependent. The aims of this work were: (i) to determine the prevalence of H. pylori by type of chronic gastritis; (ii) to describe the frequency of cagA, babA2 and vacA genotypes in strains from patients with different types of chronic gastritis; (iii) to characterize the variable region of cagA alleles.
A total of 164 patients with chronic gastritis were studied. Altogether, 50 H. pylori strains were isolated, and the status of cagA, babA2 and vacA genotypes was examined by PCR. cagA EPIYA segment identification was performed using PCR and sequencing of cagA fragments of six randomly selected strains.Results/Key findings. The overall prevalence of H. pylori was 30.5 %. Eighty percent of the isolated strains were vacA s1m1, and the cagA and babA2 genes were detected in 74 and 32 % of the strains, respectively. The most frequent genotypes were vacA s1m1/cagA/babA2 and vacA s1m1/cagA/babA2, with 40 % (20/50) and 28 % (14/50), respectively. In cagA, the most frequent EPIYA motif was -ABC (78.4 %), and EPIYA-ABCC and -ABCCC motifs were found in 10.8 % of the strains. A modified EPIYT-B motif was found in 66.6 % of the sequenced strains.
H. pylori strains carrying vacA s1m1, cagA and babA2 genotypes were the most prevalent in patients with chronic gastritis from the south of Mexico. In the cagA strains, the EPIYA-ABC motif was the most common.
幽门螺杆菌vacA s1m1/cagA/babA2的毒性基因型与严重胃部疾病相关。VacA、CagA和BabA是多态性蛋白，它们与疾病的关联依赖于等位基因。本研究的目的是：（i）按慢性胃炎类型确定幽门螺杆菌的患病率；（ii）描述不同类型慢性胃炎患者菌株中cagA、babA2和vacA基因型的频率；（iii）对cagA等位基因的可变区进行特征分析。
共研究了164例慢性胃炎患者。总共分离出50株幽门螺杆菌菌株，通过聚合酶链反应（PCR）检测cagA、babA2和vacA基因型的状态。使用PCR和对6株随机选择菌株的cagA片段进行测序来鉴定cagA EPIYA区段。结果/主要发现。幽门螺杆菌的总体患病率为30.5%。分离出的菌株中有80%为vacA s1m1，cagA和babA2基因分别在74%和32%的菌株中被检测到。最常见的基因型是vacA s1m1/cagA/babA2和vacA s1m1/cagA/babA2，分别占40%（20/50）和28%（14/50）。在cagA中，最常见的EPIYA基序是-ABC（78.4%），10.8%的菌株中发现了EPIYA-ABCC和-ABCCC基序。在66.6%的测序菌株中发现了一种修饰的EPIYT-B基序。
携带vacA s1m1、cagA和babA2基因型的幽门螺杆菌菌株在墨西哥南部慢性胃炎患者中最为普遍。在cagA菌株中，EPIYA-ABC基序最为常见。
