基于胃黏膜活检对儿童幽门螺杆菌多重耐药及毒力基因分型的关联性分析

目的探讨儿童幽门螺杆菌(Hp)毒力基因VacA与抗生素耐药的关联性。方法、招募2019年1~12月良性胃病患儿430例。通过胃镜下活检对获得胃黏膜组织中Hp进行分离培养,其中249例患儿存在阳性Hp菌株。采用琼脂稀释法检测Hp对6种抗生素耐药性。通过PCR扩增检测Hp毒力基因VacA,结合Sanger测序结果对VacA进行分型。结果分离获得的249例Hp菌株对克拉霉素、左氧氟沙星和甲硝唑的耐药率分别为60.24%、42.17%和78.31%,未发现对阿莫西林、吠喃唑酮、盐酸四环素耐药Hp菌株。Hip对抗生素双重耐药66例(26.51%),三重耐药81例(32.53%)。VacA基因的检出率为100%,其中VacAsl、VacA.2、VacAml及VacAm2检出率分别为98.80%、1.20%、38.55%及61.45%。其中,基因亚型VacAslml(高毒素活性)和VacAslm2(次高毒素活性)分别占比37.35%和61.45%。三重耐药型Hp在不同毒力基因亚型之间差异有统计学意义(P<0.05),高毒素活性的Hp在抗生素单一耐药、双重耐药及三重耐药之间差异有统计学意义(P<0.05)。结论儿童Hp毒力基因VacA分型与抗生素耐药间存在关联性,高毒素活性Hp更容易发生多重耐药现象。

Objective To explore the relationship between virulence gene VacA and antibiotic resistance in Helicobacter pylori(Hp)in children.Methods A total of 430 children with benign gastric disease in our hospital were recmited from January to December 2019.Hp was isolated and cultured from gastric mucos.il tissue by biopsy under gastroscopy and positive Hp strains were found in 249 children.The agar dilution method was used to detect the resistance of Hp to 6 antibiotics.The Hp virulence gene VacA w«is detected by PCR amplification,and VacA was typed according to the results of Sanger sequencing.Results The resistance rates of the 249 isolated strains to 6 antibiotics were:clarithromycin 60.24%,levofloxacin 42.17%,metronidazole 78.31%.There were no strains resistant to amoxicillin,furazolidone and tetracycline hydrochloride.Among them,there were 66 cases(26.51%)with dual antibiotic resistance and 81 cases(32.53%)with triple antibiotic resistance.The detection rate of VacA gene was 100%,and the detection rates of VacAsl,VacAs2,VacAml and VacAm2 were 98.80%,1.20%,38.55%and 61.45%,respectively.The genotypes VacAslml(high toxin activity)and VacAsl m2(second highest toxin activity)accounted for 37.35%and 61.45%,respec tively.The Hp with triple resistance type had obvious difference between the vimlence genotypes VacAslml and VacAsl m2(P<0.05).The Hp of high toxin activity was significantly different between the three types of single resistance,double resistance and triple resistance(P<0.05).Conclusion There is a relationship between vimlence gene VacA and antibiotic resistance in Hp in children.The Hp of high toxin activity is more likely to produce multiple antibiotic resistance.