AIM To evaluate the association between virulence factor status and antibiotic resistance in Helicobacter pylori(H. pylori)-infected patients in Ireland. METHODS DNA was extracted from antral and corpus biopsies obtai...AIM To evaluate the association between virulence factor status and antibiotic resistance in Helicobacter pylori(H. pylori)-infected patients in Ireland. METHODS DNA was extracted from antral and corpus biopsies obtained from 165 H. pylori-infected patients. Genotyping for clarithromycin and fluoroquinolone-mediating mutations was performed using the Genotype Helico DR assay. cag A and vac A genotypes were investigated using PCR. RESULTS Primary, secondary and overall resistance rates for clarithromycin were 50.5%(n = 53/105), 78.3%(n = 47/60) and 60.6%(n = 100/165), respectively. Primary, secondary and overall resistance rates for fluoroquinolones were 15.2%(n = 16/105) and 28.3%(n = 17/60) and 20%(n = 33/165), respectively. Resistance to both antibiotics was 12.4%(n = 13/105) in treatment-na?ve patients, 25%(n = 15/60) in those previously treated and 17%(n = 28/165) overall. A cag A-positive genotype was detected in 22.4%(n = 37/165) of patient samples. The dominant vac A genotype was S1/M2 at 44.8%(n = 74/165), followed by S2/M2 at 26.7%(n = 44/165), S1/M1 at 23.6%(n = 39/165) and S2/M1 at 4.8%(n = 8/165). Primary clarithromycin resistance was significantly lower in cag A-positive strains than in cag A-negative strains [32%(n = 8/25) vs 56.3%(n = 45/80); P = 0.03]. Similarly, in patients infected with more virulent H. pylori strains bearing the vac A s1 genotype, primary clarithromycin resistance was significantly lower than in those infected with less virulent strains bearing the vac A s2 genotype, [41%(n = 32/78) vs 77.8%(n = 21/27); P = 0.0001]. No statistically significant association was found between primary fluoroquinolone resistance and virulence factor status.CONCLUSION Genotypic H. pylori clarithromycin resistance is high and cag A-negative strains are dominant in our population. Less virulent(cag A-negative and vac A S2-containing) strains of H. pylori are associated with primary clarithromycin resistance.展开更多
目的明晰我国氟喹诺酮类药物耐药结核分枝杆菌株gyrA、gyrB基因突变的分子特征。方法以检索式"quinolones resistance AND Mycobacterium tuberculosis AND(China OR Hong Kong OR Tai Wan OR Macon)"和"结核AND喹诺酮耐...目的明晰我国氟喹诺酮类药物耐药结核分枝杆菌株gyrA、gyrB基因突变的分子特征。方法以检索式"quinolones resistance AND Mycobacterium tuberculosis AND(China OR Hong Kong OR Tai Wan OR Macon)"和"结核AND喹诺酮耐药"分别在英文数据库(pubmed、Embase、SciFinder)和中文数据库(万方、中国知网、中国生物医学文献服务系统与维普期刊资源服务平台)中检索有关我国结核分枝杆菌喹诺酮类药物耐药基因突变的研究文献,对符合纳入标准的文献中氟喹诺酮耐药基因gyrA、gyrB进行突变位点和氨基酸变化类型等计数资料的信息提取和分析。结果 32篇外文和23篇中文文献纳入研究,3 641株氟喹诺酮类耐药结核分枝杆菌的gyrA基因得到分析,其中1 958株同时分析了gyrB基因。3 641株耐药菌中,2 830株检测到gyrA基因突变(突变率为77.73%),共47种突变类型,均为氨基酸错义突变,其中单位点、双位点突变的发生率分别为75.83%和1.92%,94、90、91位密码子突变率分别为49.33%(1 796/3 641)、19.14%(697/3 641)、5.80%(211/3 641),出现频率最高的突变类型依次为Asp94Gly、Ala90Val、Asp94Ala、Asp94Asn、Ser91Pro、Asp94Try;1 958株耐药菌中,175株发生gyrB基因突变(突变率为8.94%),其中56株的29个突变类型为gyrB单基因突变,其余119株36种突变类型与gyrA基因突变共同发生,占gyrB序列突变的68%。结论我国结核分枝杆菌氟喹诺酮耐药株gyrA基因突变以94、90、91位密码子单位点突变为主;gyrB基因突变位点较为分散,常与gyrA基因突变伴随发生。展开更多
基金Supported by the Health Research Board(HRA-POR-2014-526)
文摘AIM To evaluate the association between virulence factor status and antibiotic resistance in Helicobacter pylori(H. pylori)-infected patients in Ireland. METHODS DNA was extracted from antral and corpus biopsies obtained from 165 H. pylori-infected patients. Genotyping for clarithromycin and fluoroquinolone-mediating mutations was performed using the Genotype Helico DR assay. cag A and vac A genotypes were investigated using PCR. RESULTS Primary, secondary and overall resistance rates for clarithromycin were 50.5%(n = 53/105), 78.3%(n = 47/60) and 60.6%(n = 100/165), respectively. Primary, secondary and overall resistance rates for fluoroquinolones were 15.2%(n = 16/105) and 28.3%(n = 17/60) and 20%(n = 33/165), respectively. Resistance to both antibiotics was 12.4%(n = 13/105) in treatment-na?ve patients, 25%(n = 15/60) in those previously treated and 17%(n = 28/165) overall. A cag A-positive genotype was detected in 22.4%(n = 37/165) of patient samples. The dominant vac A genotype was S1/M2 at 44.8%(n = 74/165), followed by S2/M2 at 26.7%(n = 44/165), S1/M1 at 23.6%(n = 39/165) and S2/M1 at 4.8%(n = 8/165). Primary clarithromycin resistance was significantly lower in cag A-positive strains than in cag A-negative strains [32%(n = 8/25) vs 56.3%(n = 45/80); P = 0.03]. Similarly, in patients infected with more virulent H. pylori strains bearing the vac A s1 genotype, primary clarithromycin resistance was significantly lower than in those infected with less virulent strains bearing the vac A s2 genotype, [41%(n = 32/78) vs 77.8%(n = 21/27); P = 0.0001]. No statistically significant association was found between primary fluoroquinolone resistance and virulence factor status.CONCLUSION Genotypic H. pylori clarithromycin resistance is high and cag A-negative strains are dominant in our population. Less virulent(cag A-negative and vac A S2-containing) strains of H. pylori are associated with primary clarithromycin resistance.
文摘目的明晰我国氟喹诺酮类药物耐药结核分枝杆菌株gyrA、gyrB基因突变的分子特征。方法以检索式"quinolones resistance AND Mycobacterium tuberculosis AND(China OR Hong Kong OR Tai Wan OR Macon)"和"结核AND喹诺酮耐药"分别在英文数据库(pubmed、Embase、SciFinder)和中文数据库(万方、中国知网、中国生物医学文献服务系统与维普期刊资源服务平台)中检索有关我国结核分枝杆菌喹诺酮类药物耐药基因突变的研究文献,对符合纳入标准的文献中氟喹诺酮耐药基因gyrA、gyrB进行突变位点和氨基酸变化类型等计数资料的信息提取和分析。结果 32篇外文和23篇中文文献纳入研究,3 641株氟喹诺酮类耐药结核分枝杆菌的gyrA基因得到分析,其中1 958株同时分析了gyrB基因。3 641株耐药菌中,2 830株检测到gyrA基因突变(突变率为77.73%),共47种突变类型,均为氨基酸错义突变,其中单位点、双位点突变的发生率分别为75.83%和1.92%,94、90、91位密码子突变率分别为49.33%(1 796/3 641)、19.14%(697/3 641)、5.80%(211/3 641),出现频率最高的突变类型依次为Asp94Gly、Ala90Val、Asp94Ala、Asp94Asn、Ser91Pro、Asp94Try;1 958株耐药菌中,175株发生gyrB基因突变(突变率为8.94%),其中56株的29个突变类型为gyrB单基因突变,其余119株36种突变类型与gyrA基因突变共同发生,占gyrB序列突变的68%。结论我国结核分枝杆菌氟喹诺酮耐药株gyrA基因突变以94、90、91位密码子单位点突变为主;gyrB基因突变位点较为分散,常与gyrA基因突变伴随发生。
