快速AS—PCR技术用于血小板HPA—1,—2,—3,—4,—5？…

目的 研究建立快速等位基因特异性（ＡＳ）引物－ＰＣＲ技术,同时对人血小板同种异型抗原系统（ＨＰＡ－１,２,３,４,５０等位基因进行分型。方法 设计合成１５闰基因特异性引物,摸索最适引物浓度、Ｍｇ＾＋＋浓度及护增参数。用该技术对１００名北京地区健康献血者ＨＰＡ－１￣５系统等位基因进行分型。结果 从１００名北京地区献血员观察到的ＨＰＡ基因频率分别是ＨＰＡ－１ａ和１ｂ为０．９９５和０．００５,ＨＰＡ－２     

海南岛黎族人血小板1～17抗原系统基因多态性研究

目的 调查海南岛黎族人群血小板抗原基因(human platelet alloantigens,HPA)1～17等位基因多态性,分析不同民族的差异,评估其在随机输血中供受者HPA不配合比例,为黎族人群临床血小板输注提供实验依据.方法 采用聚合酶链反应-序列特异性引物方法 对180名黎族人HPA-1～17抗原系统34个等位基因分型.结果 黎族人HPA的等位基因频率分别为:HPA-2a:0.9972,-2b:0.0028,-3a,0.4889,3b:0.5111,5a:0.9667,-5b:0.0333,-6a:0.9972,-6b:0.0028,-15a:0.4250,-15b:0.5750,其余HPA-1、-4、7、-14、-16、-17系统未检出相应HPA-b等位基因.结论 本研究结果 揭示了黎族人HPA-1～17基因型和等位基因频率分布概况,提示黎族人HPA基因频率分布具有黎族人独有的特点.在随机血小板输注中,HPA不配合的机会依次为:HPA-3为37.49%、HPA-15为36.93%、HPA-5为6.23%,只需检测供、受者HPA-3、-5、-15基因相合,就可基本达到血小板匹配性输注.     

海南岛黎族人血小板1～17抗原系统基因多态性研究

目的 调查海南岛黎族人群血小板抗原基因(human platelet alloantigens,HPA)1～17等位基因多态性,分析不同民族的差异,评估其在随机输血中供受者HPA不配合比例,为黎族人群临床血小板输注提供实验依据.方法 采用聚合酶链反应-序列特异性引物方法 对180名黎族人HPA-1～17抗原系统34个等位基因分型.结果 黎族人HPA的等位基因频率分别为:HPA-2a:0.9972,-2b:0.0028,-3a,0.4889,3b:0.5111,5a:0.9667,-5b:0.0333,-6a:0.9972,-6b:0.0028,-15a:0.4250,-15b:0.5750,其余HPA-1、-4、7、-14、-16、-17系统未检出相应HPA-b等位基因.结论 本研究结果 揭示了黎族人HPA-1～17基因型和等位基因频率分布概况,提示黎族人HPA基因频率分布具有黎族人独有的特点.在随机血小板输注中,HPA不配合的机会依次为:HPA-3为37.49%、HPA-15为36.93%、HPA-5为6.23%,只需检测供、受者HPA-3、-5、-15基因相合,就可基本达到血小板匹配性输注.     

海南岛黎族人血小板1～17抗原系统基因多态性研究

目的 调查海南岛黎族人群血小板抗原基因(human platelet alloantigens,HPA)1～17等位基因多态性,分析不同民族的差异,评估其在随机输血中供受者HPA不配合比例,为黎族人群临床血小板输注提供实验依据.方法 采用聚合酶链反应-序列特异性引物方法 对180名黎族人HPA-1～17抗原系统34个等位基因分型.结果 黎族人HPA的等位基因频率分别为:HPA-2a:0.9972,-2b:0.0028,-3a,0.4889,3b:0.5111,5a:0.9667,-5b:0.0333,-6a:0.9972,-6b:0.0028,-15a:0.4250,-15b:0.5750,其余HPA-1、-4、7、-14、-16、-17系统未检出相应HPA-b等位基因.结论 本研究结果 揭示了黎族人HPA-1～17基因型和等位基因频率分布概况,提示黎族人HPA基因频率分布具有黎族人独有的特点.在随机血小板输注中,HPA不配合的机会依次为:HPA-3为37.49%、HPA-15为36.93%、HPA-5为6.23%,只需检测供、受者HPA-3、-5、-15基因相合,就可基本达到血小板匹配性输注.     

山西省部分地区汉族人群血小板特异性抗原基因多态性研究

目的研究山西省汉族人群血小板特异性抗原(HPA)基因多态性分布特点,丰富血小板人类遗传学资料,同时为山西地区患者血小板配型提供参考依据。方法本研究使用序列特异性引物-聚合酶链式反应(SSP-PCR)方法,对山西150例汉族成年人进行血小板特异性抗原基因分型检测。结果山西汉族人群血小板特异性抗原HPA 1-17位点中,HPA 1-6,157个位点呈现多态性,基因频率分别是1a 0.997、1b 0.003、2a 0.980、2b 0.020、3a 0.563、3b 0.437、4a0.997、4b 0.003、5a 0.960、5b 0.040、6a 0.970、6b 0.030、15a 0.490、15b 0.510。结论山西省汉族人群血小板特异性抗原有其特有的地域特点,人类血小板特异性抗原基因有明显的地域种族多态性分布规律。     

血小板特异性抗体及HLA抗体引起血小板输注无效的研究

目的分析血小板输注无效（PTR）患者血小板同种抗体,并对其HPA及HLA-Ⅰ类抗原进行基因分型,探讨血小板输注无效与血小板同种抗原／HLA—Ⅰ类抗原相关性。方法应用ELISA方法对17例血小板输注无效患者血清中的血小板抗体进行检测;运用PCR—SSP方法,采用HPA分型试剂盒检测血小板同种抗原7个抗原系统HPA-1、2、3、4、5、6、15,以及HLA分型试剂盒对HLA—A／B抗原进行基因分型。结果6名患者单独表达HLA抗体,4名患者表达血小板特异性糖蛋白抗体,3例HLA抗体和血小板特异性糖蛋白抗体共同表达．其中以GPⅡb／Ⅲa为主。对17例患者HPA系统和HLA-Ⅰ类抗原基因分型,发现HPA-3系统中a的基因频率高达0．676,b为0．324;HLA—A＊02、HLA—A＊24、HLA—A＊11和HLA—B＊60、HLA—B＊13、HLA—B＊46多见。结论HLA抗体和血小板特异性糖蛋白抗体表达引起血小板输注无效,了解胛R与HPA／HLA—Ⅰ类抗原的相关性对指导临床血小板配合性输注具有重要意义。     

黑龙江省满族人群血小板抗原1～17系统基因多态性的研究

目的 探讨黑龙江省满族人群人类血小板抗原(HPA)1～17系统基因多态性及其表达频率,建立HPA基因型资料库.方法 选择101例满族的健康无血缘关系的人群为研究对象,采用PCR-SSP技术,对HPA1～17共17个抗原系统34个等位基因进行分型,分别计算其基因频率、基因型频率.结果 黑龙江省满族人群HPA-1a、2a、3a、5a、6a、15a基因频率分别是0.99505、0.940595、0.549505、0.99505、0.9802、0.445545,HPA-4a、7a～14a、16a和17a均为1.0;HPA-1b、2b、3b、5b、6b、15b基因频率分别是0.00495、0.059405、0.450495、0.00495、0.0198、0.554455,未检测出HPA-4b、7b～14b、16b和17b.调查和分析的HPA基因组合型及其频率发现满族人群HPA基因有22种组合型,其中仅有3种基因组合型频率＞10％(42.57％),另外19种基因组合型的频率均＜10％(57.43％).黑龙江省满族HPA基因频率与黑龙江省汉族相比,HPA-3a、3b基因频率差异具有统计学意义(P＜0.05).结论 黑龙江省满族健康人群HPA1～ 17基因频率的分布与汉族人群相比有相似之处,也有本民族的自身特点.HPA-3,15系统具有高度多态性,在随机血小板输注中,供受者HPA-3、HPA-15系统不配合的机会分别为37.25％、37.20％,易发生血小板不配合而造成的同种免疫,是HPA配合性输注关注重点.     

血小板特异性基因(HPA-1～17)在广州地区人群中分布的多态性研究

目的:调查在广州地区人群中HPA-1～17基因的多态性及其表达频率。方法:采用序列特异性引物-聚合酶链反应(SSP-PCR)对500名健康的血小板捐献者的HPA基因进行分型。结果:广州地区健康的血小板捐献者中表达出HPA-a基因中的1a～17a基因;各基因独立的分布频率中,HPA-1a(99.8%)、2a(99.85%)、3a(56.3%)、4a(99.9%)、5a(98.8%)、6a(98.6%)、15a(55.1%),HPA-7a～14a、16a、17a均为100%。仅表达HPA-b基因中的1b、2b、3b、4b、5b、6b和15b,分布频率为HPA-1b(0.2%)、2b(0.15%)、3b(43.7%)、4b(0.1%)、5b(1.2%)、6b(1.4%)、15b(44.9%);未表达HPA-7b、8b、9b、10b、11b、12b、13b、14b、16b和17b;说明HPA-1a～17a和HPA-3b、15b在广州地区为高频率基因。在与中国汉族不同地区HPA基因多态性分布的比较分析中发现,广州地区人群中HPA基因频率与北京地区人群的差异较明显;在与部分国家民族人群的比较分析中发现,广州地区人群中HPA基因频率与欧洲、美国、英国和埃及人群有较明显差异,而与日本和泰国人群的差异较小。文中调查和分析了HPA基因组合型及其频率,发现广州地区HPA基因有40种组合型,其中仅有5种基因组合型频率10%(占25%),另外35种基因组合型的频率均9%(占75%)。结论:数据提示广州地区人群中HPA基因遗传距离较接近。HPA基因表达和分布频率在中国汉族人群中存在南北差异。与不同亚洲以外的种族和国家之间亦表现出基因表达和分布的差异。HPA基因多态性研究数据有利于指导地区性血小板供者库库容的设计,配合临床开展选择适合性血小板输注,避免同种免疫造成的血小板输注无效,且对开展HPA相关临床研究具有重要意义。     

中国山东地区汉族人群血小板特异性抗原-15基因多态性分析

目的:分析山东地区汉族人群血小板特异性抗原(HPA)15基因多态性分布特点。方法:采用PCR-序列特异性引物(PCR-SSP)技术对108例无血缘关系汉族人进行HPA-15基因分型,计算等位基因频率、基因型频率并与其他种族、地区人群相关资料比较。结果:等位基因HPA-15a和HPA-15b分布频率分别为0.5139和0.4861;基因型HPA-15a15b、-15a15a、-15b15b频率依次为0.2407、0.2130、0.5463;HPA-15基因分布与越南、德国、奥地利人近似,而与印地安人差异有显著性(P<0.05)。结论:山东地区汉族人HPA-15基因存在多态性,并具有明显的种族和地域性差异。     

应用PCR-RFLP技术检测人血小板抗原-1基因型

特异性血小板对偶抗原是由血小板膜糖蛋白 (GP)基因发生单碱基突变 ,导致抗原决定簇上的一个氨基酸发生变异造成的。人血小板抗原 - 1(human platelet antigen- 1,HPA- 1)的对偶抗原 HPA- 1a和 HPA- 1b由一对等位基因控制 ,这对基因来自GP a基因 C12 ,5 48T错义突变 [1 ]。目前已经发展了多种检测单碱基突变的技术 [2 ] ,均有材料来源不受限制的特点。我们选用 PCR- RFL P技术测定了武汉地区 180名无血缘关系的献血员 HPA- 1基因型。1　对象与方法1.1　对象　武汉地区 180名无血缘关系献血员的 EDTA抗凝血。1.2　人白细胞基因组…     

Human platelet alloantigens (HPAs): PCR-SSP genotyping of a UK population for 15 HPA alleles.

Alloimmunization to human platelet alloantigens (HPAs) is responsible for neonatal alloimmune thrombocytopenia (NAIT), post-transfusional purpura (PTP) and platelet transfusion refractoriness. HPAs may also have a role as histocompatibility antigens in transplantation as well as associations with cardiac disease. We have developed a polymerase chain reaction-sequence-specific primer (PCR-SSP) assay capable of detecting 15 HPA allelic variants. As part of the validation of the assay, 134 UK renal donors were genotyped to determine HPA allele frequencies in the UK population. The HPA allele frequencies obtained are consistent with those of the other European studies: GP1A*1 (HPA-5a) and GP1A*2 (HPA-5b), 0.914 and 0.086, respectively; GP1BA*1 (HPA-2a) and GP1BA*2 (HPA-2b), 0.925 and 0.075; GP2B*1 (HPA-3a) and GP2B*2 (HPA-3b), 0.627 and 0.373; GP3A*1 (HPA-1a) and GP3A*2 (HPA-1b), 0.840 and 0.161. The rare alleles GP2B*3 (HPA-9bw) and GP3A*3 to *8 (HPA-4b, -6b, -7bw, -8bw, -10bw and -11bw, respectively) were all absent. This comprehensive HPA genotyping assay allows rapid, accurate and reproducible results at low cost.     

Genotyping for human platelet-specific antigens HPA-1, -2, -3, -4 and -5 in the Slovenian population reveals a slightly increased frequency of HPA-1b and HPA-2b as compared to other European populations

Typing of human platelet alloantigens (HPA) is necessary in various clinical situations. The purpose of this study was to type a random sample of the Slovenian population for HPA alleles, in order to obtain genetic population data. A total of 152 unrelated Slovenian blood donors were genotyped for HPA-1, -2, -3, -4 and -5 alleles using a simple method that enables simultaneous and complete determination of HPA genotypes. Ten different polymerase chain reactions employing sequence-specific priming (PCR-SSP), which worked in identical cycling conditions, were used. The allele frequencies were 0.809 for HPA-1a, 0.191 for HPA-1b, 0.891 for HPA-2a, 0.109 for HPA-2b, 0.591 for HPA-3a, 0.407 for HPA-3b, 0.997 for HPA-4a, 0.00 for HPA-4b, 0.934 for HPA-5a and 0.066 for HPA-5b. When compared to results of studies of various other Caucasian populations, our population displayed a slightly but not significantly higher proportion of the HPA-1b and 2b alleles.     

Genotyping for human platelet-specific antigens HPA-1, -2, -3, -4 and -5 in the Slovenian population reveals a slightly increased frequency of HPA-1b and HPA-2b as compared to other European populations.

Typing of human platelet alloantigens (HPA) is necessary in various clinical situations. The purpose of this study was to type a random sample of the Slovenian population for HPA alleles, in order to obtain genetic population data. A total of 152 unrelated Slovenian blood donors were genotyped for HPA-1, -2, -3, -4 and -5 alleles using a simple method that enables simultaneous and complete determination of HPA genotypes. Ten different polymerase chain reactions employing sequence-specific priming (PCR-SSP), which worked in identical cycling conditions, were used. The allele frequencies were 0.809 for HPA-1a, 0.191 for HPA-1b, 0.891 for HPA-2a, 0.109 for HPA-2b, 0.591 for HPA-3a, 0.407 for HPA-3b, 0.997 for HPA-4a, 0.00 for HPA-4b, 0.934 for HPA-5a and 0.066 for HPA-5b. When compared to results of studies of various other Caucasian populations, our population displayed a slightly but not significantly higher proportion of the HPA-1b and 2b alleles.     

A modified PCR-RFLP genotyping method demonstrates the presence of the HPA-4b platelet alloantigen in a North American Indian population

The diallelic HPA-4 (Pen/Yuk) platelet alloantigen system is polymorphic in Asian populations and accounts for the majority of cases of neonatal alloimmune thrombocytopenia in Japan. At the molecular level, the HPA-4a/4b dimorphism is associated with an arginine/ glutamine substitution at amino acid 143 of the gene encoding platelet glycoprotein IIIa. Unlike the five other major diallelic human platelet antigen systems (HPA-1, -2, -3, -5, and -6), the nucleotide substitution corresponding to the HPA-4 antigen system does not involve a common naturally occurring restriction enzyme site. This paper describes a new genotyping method for HPA-4 (polymerase chain reaction-restriction fragment length polymorphism [PCR-RFLP]) that involves restriction enzyme digestion of PCR-amplified genomic DNA using a modified PCR primer to create an artificial TaqI restriction site that is present in the HPA-4a but not in the HPA-4b DNA sequence. The HPA-4 PCR-RFLP method was validated by testing a reference panel of 10 known HPA-4 genotyped Japanese individuals. Thus, genotyping by PCR-RFLP can now be performed for all six major HPA systems. Using the HPA-4 PCR-RFLP genotyping method, we determined a frequency of 2.9 percent for the HPA-4b allele in a North American Indian population. This finding indicates the importance of the HPA-4 antigen system as a potential cause of alloimmune thrombocytopenia in American Indians.     

Frequency of platelet-specific alloantigens in a Danish population

This study reports the first data on gene frequencies of platelet alloantigens HPA-1, HPA-2, HPA-3, HPA-4 and HPA-5 in a population of unrelated Danish blood donors using PCR-techniques. The observed gene frequencies fit the Hardy-Weinberg equilibrium, and the calculated phenotype frequencies are similar to those obtained in other Caucasian populations: HPA-la and -lb occur in 96.6% and 30.3% of 557 unrelated respectively. HPA-2a and -2b in 99.4% and 15.9% of 163 tested, HPA-3a and -3b in 88.3% and 63.2% of 163 tested, HPA-4a and -4b in 100% and 0% of 131 tested, and finally HPA-5a and -5b in 100% and 15.7% of 427 tested. It is a major technical improvement to use PCR techniques for genomic typing of HPA. Not only is it possible to perform HPA typings in severely thrombocytopenic patient and on amniotic fluid cells of the fetus of alloimunized mothers, but it must be expected that accuracy of the HPA typing will increase considerably, as has been the case with genomic HLA class II typing. Finally, use of PCR technique combined with allele-specific primers is suitable for accurate large scale typing of platelet donors, which may be useful in special clinical settings.     

Gene frequencies of the HPA-1 to HPA-13, Oe and Gov platelet antigen alleles in Taiwanese,Indonesian, Filipino and Thai populations

Human platelet antigen (HPA) systems consist of more than twelve bi-allelic antigen polymorphisms in which a base pair substitution leads to change in an amino acid of a glycoprotein expressed on the platelet. The neonatal alloimmune thrombocytopenia (NAIT), post transfusion purpura, and refractoriness to platelet transfusion can be induced by antibodies against human platelet antigens: e.g. HPA-1a, 3a, 4a, 5a, and Gova. HPA typing is essential for the diagnosis and treatment of a variety of diseases. We developed a PCR-based method to detect HPA-1 to HPA-13, Oe and Gov platelet alloantigens. In this method, the amplified PCR products were used to recognize the polymorphism after restriction enzyme digestions. Among 566 Taiwanese, 107 Indonesian, 100 Filipino and 137 Thai subjects studied, HPA-1a, 2a, 4a, 5a, 6a, 7aW, 8aW, 9a, 10a, 11a, 12a, 13a, Oea genes were present in every sample; while HPA-1b, 2b, 4b, 5b and 6b were rarely found. HPA-7aW, 8aW, 9, 10, 11, 12, 13, and Oea alleles were noted to be monomorphic only. HPA-3a/3b alleles had frequencies of 0.595/0.405, 0.505/0.495, 0.507/0.493, 0.530/0.470, while Gova/Govb of 0.462/0.538, 0.450/0.550, 0.463/0.537, 0.520/0.480 among Taiwanese, Indonesians, Thais and Filipinos respectively. The prevalence rates of HPA-1 to 13 in this study were also consistent with other previous reports using different methods. The alloimmunization due to Gov and HPA-3 antigens need to be emphasized in these populations.     

Gene frequencies of the HPA-1 to 6 and Gov human platelet antigens in Thai blood donors

Human platelet alloantigens (HPA) are important in neonatal alloimmune thrombocytopenia (NAIT), posttransfusion purpura (PTP), platelet transfusion refractoriness, passive alloimmune thrombocytopenia, and transplantation-associated alloimmune thrombocytopenia. Thus, HPA genotyping is essential in diagnosis and treatment. We analyzed HPA-1 to 6 and Gov alleles, using PCR with sequence specific primers (PCR-SSP) in 500 Thai blood donors who had been HLA class I antigen typed. HPA-4a was present in all samples. HPA-1b, -2b, -5b, and -6b were rare, and HPA-4b was not found. HPA-3a and -3b showed frequencies of 56.0 percent and 44.0 percent, respectively. Gova and Govb showed frequencies of 49.1 percent and 50.9 percent, respectively. The prevalence rates of HPA-1 to 6 gene frequencies (GFs) were consistent with those of other Asian populations rather than those of Caucasians. We also report on the GFs of Gova and Govb, which also are comparable to those of Asian populations. Our results could establish a useful HPA- and HLA-matched plateletpheresis donor file and provide an improvement of platelet alloantibody detection in alloimmune thrombocytopenic patients, and, therefore, a more effective platelet transfusion program.     

Genetic landscape of human platelet antigen variants in the Indian population analysed from 1029 whole genomes

Genetic variants in human platelet antigens (HPAs) considered allo- or auto antigens are associated with various disorders, including neonatal alloimmune thrombocytopenia, platelet transfusion refractoriness and post-transfusion purpura. Although global differences in genotype frequencies were observed, the distributions of HPA variants in the Indian population are largely unknown. This study aims to explore the landscape of HPA variants in India to provide a basis for risk assessment and management of related complications. Population-specific frequencies of genetic variants associated with the 35 classes of HPAs (HPA-1 to HPA-35) were estimated by systematically analysing genomic variations of 1029 healthy Indian individuals as well as from global population genome datasets. Allele frequencies of the most clinically relevant HPA systems in the Indian population were found as follows, HPA-1a – 0.884, HPA-1b – 0.117, HPA-2a – 0.941, HPA-2b – 0.059, HPA-3a – 0.653, HPA-3b – 0.347, HPA-4a – 0.999, HPA-4b – 0.0010, HPA-5a – 0.923, HPA-5b – 0.077, HPA-6a – 0.998, HPA-6b – 0.002, HPA-15a – 0.582 and HPA-15b – 0.418. This study provides the first comprehensive analysis of HPA allele and genotype frequencies using large scale representative whole genome sequencing data of the Indian population.     

Comparison of human platelet antigen (HPA)-1a typing by solid phase red cell adherence to HPA-1 allotypes determined by allele-specific restriction enzyme analysis

Phenotype results for human platelet antigen (HPA)-1 by Capture-P(R), (Immucor, Inc., Norcross, GA) solid phase red cell adherence (SPRCA) were compared to results of allele-specific restriction enzyme analysis (ASRA) for the determination of HPA-1 allotype. Because the expression of HPA-1a and HPA-1b is determined by a single nucleotide substitution of thymine --> cytosine at position 196 of the gene encoding membrane glycoprotein (GP)-IIIa, it is possible to distinguish the alternate forms of the gene using ASRA. Primers (5'- GCTCCAATGTACGGGGTAAACTC-3' and 5'-CAGACCTCCACCTTGTGCTCTATG- 3') were designed to amplify the region of DNA that contains the polymorphism and a restriction enzyme (Nci I) was used to cleave the DNA in a predictable manner. Platelet-rich plasma for immunophenotying and anticoagulated whole blood for DNA extraction were obtained from 159 platepheresis donors. Of 159 SPRCA tests, 138 were valid and 21 were invalid due to positive autologous controls. For 135 HPA-1a-positive and 2 HPA-1a-negative phenotype tests the DNA typing results correlated: 135 positive samples were either HPA-1a/a or HPA-1a/b and 2 negative samples were HPA-1b/b. One donor that typed as HPA-1b/b by ASRA had a positive result of 2+ on SPRCA. This donor had been previously typed by SPRCA as HPA-1a-negative and DNA typed as HPA-1b/b by our laboratory. Based on these findings results of = 3+ by SPRCA are interpreted as HPA-1a-positive for donor screening purposes. SPRCA test results of = 2+ are considered equivocal and the HPA-1 allotype is determined by ASRA. HPA-1a-negative donors by SPRCA must be confirmed as HPA-1b/b by ASRA prior to issue for a patient that requires HPA-1anegative platelets.     

Rapid detection of point mutations conferring resistance to fluoroquinolone in gyrA of Helicobacter pylori by allele-specific PCR

Helicobacter pylori strains with reduced susceptibility to fluoroquinolones have a mutation at either codon 87 Asn or 91 Asp of the gyrA gene. A rapid test based on an allele-specific PCR (AS-PCR) was designed to detect the gyrA mutations. Clinical H. pylori isolates were obtained from the stomachs of 51 patients with H. pylori infections who showed treatment failure. The MICs of gatifloxacin (GAT) were determined by the agar dilution method. Identical genotyping results were obtained with AS-PCR and conventional PCR. The gyrA mutations of H. pylori causing reduced susceptibility to fluoroquinolones could be detected successfully by this method. A significant association was observed between the presence of mutations, as detected by AS-PCR, and the resistance of the strains to GAT. Moreover, genotyping by AS-PCR took less than 3 to 4 h. The AS-PCR method for the detection of gyrA mutations in H. pylori is useful for easy identification of fluoroquinolone-resistant strains of H. pylori.