The diverse clinical presentation of Helicobacter pylori (H. pylori) infection results from the interaction between bacterial virulence, host genetics, socio-demographic and environmental factors. This study aimed to ...The diverse clinical presentation of Helicobacter pylori (H. pylori) infection results from the interaction between bacterial virulence, host genetics, socio-demographic and environmental factors. This study aimed to characterize Helicobacter pylori virulence genes and the associated behavioral factors among dyspeptic patients in Burkina Faso. Two hundred and fifty (250) stool samples were collected from patients with dyspepsia seen at health centers in Ouagadougou, Burkina Faso. Bacterial deoxyribonucleic acid (DNA) was extracted using a commercial kit. Virulence genes were detected using conventional multiplex Polymerase Chain Reaction with specific primers. The overall prevalence of Helicobacter pylori of the 250 participants was 91.20%. CagA virulence gene was present among 20.19% of individuals, while babA2 and vacA were detected respectively among 9.65% and 67.54% of the population positive for Helicobacter pylori. Among vacA subtypes, vacAs1 was the most frequent, with 39.04%, followed by vacAi1 (19.74%), vacAi2 (17.54%), and vacAs2 with 10.96%. Regarding vacAm1 and vacAm2, they were less frequent at 6.14% each. “Handwashing three times or less per day” significantly increased the risk of having vacAi2 allele and H. pylori rRNA16s, with p-values of 0.013 and 0.020, respectively. The consumption of non-tap water increases the risk of carrying the cagA virulence gene. Additionally, H. pylori-positive patients living with more than four (4) people in their household had about two times the risk of having the vacAs1 allele. The present study shows the detection of Helicobacter pylori cagA, vacA subtypes, and babA2 by stool a PCR method in Burkina Faso. The strong association between sanitary habits and virulence factors depicts the composite interaction between ecological factors, gastric mucosa, and bacteria. Therefore, the synergic action of these factors should be considered when aiming for bacterial eradication and gastric pathology cure.展开更多
The Helicobacter pylori vacuolating cytotoxin (VacA) is an intracellular, mitochondrial-targeting exotoxin that rapidly causes mitochondrial dysfunction and fragmentation. Although VacA targeting of mitochondria has b...The Helicobacter pylori vacuolating cytotoxin (VacA) is an intracellular, mitochondrial-targeting exotoxin that rapidly causes mitochondrial dysfunction and fragmentation. Although VacA targeting of mitochondria has been reported to alter overall cellular metabolism, there is little known about the consequences of extended exposure to the toxin. Here, we describe studies to address this gap in knowledge, which have revealed that mitochondrial dysfunction and fragmentation are followed by a time-dependent recovery of mitochondrial structure, mitochondrial transmembrane potential, and cellular ATP levels. Cells exposed to VacA also initially demonstrated a reduction in oxidative phosphorylation, as well as increase in compensatory aerobic glycolysis. These metabolic alterations were reversed in cells with limited toxin exposure, congruent with the recovery of mitochondrial transmembrane potential and the absence of cytochrome c release from the mitochondria. Taken together, these results are consistent with a model that mitochondrial structure and function are restored in VacA-intoxicated cells.展开更多
目的 vac A 基因编码的蛋白是幽门螺杆菌的一个重要毒力因子,通过空泡化作用损伤上皮细胞.vacA 基因与 Hp 感染者的临床发病有着密切的关系,vacA 的基因型决定毒素蛋白体外表达水平的高低.我们从幽门螺杆菌88022菌株中扩增出vacA 基因...目的 vac A 基因编码的蛋白是幽门螺杆菌的一个重要毒力因子,通过空泡化作用损伤上皮细胞.vacA 基因与 Hp 感染者的临床发病有着密切的关系,vacA 的基因型决定毒素蛋白体外表达水平的高低.我们从幽门螺杆菌88022菌株中扩增出vacA 基因毒性相关片段,进行序列测定和序列比较分析,为Hp 的临床检测奠定基础.方法以该菌株总 DNA 为模板,紧随 vacA 基因序列 s 区保守区域的引物(位于316bp～335bp 和1198bp～1218bp)扩增vacA 基因的一个903bp 片段,编码的氨基酸为34～334位,用13amHI 和 Pst Ⅰ双酶切后克隆入 pGEM-3Zf(-)质粒载体,以双脱氧法双向测定目的片段的序列,拼接出该片段的全序列,并与已知的 Hp vacA 基因序列作比较.结果所得序列与 Hp 国际标准株 CCUG17874(GeneBank gi619248)和 NCTCll638(GeneBank gi 495469)的 vacA 基因序列完全一致,氨基酸序列分析和所报道的结果一致.结论构建了 Hp vacA 基因毒性相关片段的重组克隆,为以后的进一步研究奠定了基础.展开更多
目的 :研究幽门螺杆菌空泡毒素作为单一毒力决定簇对真核细胞的作用。方法 :用 PCR扩增vac A基因片段 ,克隆入真核表达载体 p EGFP- N 1,构建重组质粒 p EGFP- vac A,转染 He L a细胞 ,通过相差显微镜和电子显微镜观察细胞形态与结构的...目的 :研究幽门螺杆菌空泡毒素作为单一毒力决定簇对真核细胞的作用。方法 :用 PCR扩增vac A基因片段 ,克隆入真核表达载体 p EGFP- N 1,构建重组质粒 p EGFP- vac A,转染 He L a细胞 ,通过相差显微镜和电子显微镜观察细胞形态与结构的变化。结果 :重组质粒转染 He L a细胞 2 4 h,10 %～ 2 0 %细胞的胞质内出现明显空泡 ,其中少数细胞发生凋亡改变。结论 :成功构建了用于真核表达的重组 vac A质粒 ,转染真核细胞后 ,观察 Vac A作用导致的细胞形态结构的变化 ,为研究 Vac展开更多
文摘The diverse clinical presentation of Helicobacter pylori (H. pylori) infection results from the interaction between bacterial virulence, host genetics, socio-demographic and environmental factors. This study aimed to characterize Helicobacter pylori virulence genes and the associated behavioral factors among dyspeptic patients in Burkina Faso. Two hundred and fifty (250) stool samples were collected from patients with dyspepsia seen at health centers in Ouagadougou, Burkina Faso. Bacterial deoxyribonucleic acid (DNA) was extracted using a commercial kit. Virulence genes were detected using conventional multiplex Polymerase Chain Reaction with specific primers. The overall prevalence of Helicobacter pylori of the 250 participants was 91.20%. CagA virulence gene was present among 20.19% of individuals, while babA2 and vacA were detected respectively among 9.65% and 67.54% of the population positive for Helicobacter pylori. Among vacA subtypes, vacAs1 was the most frequent, with 39.04%, followed by vacAi1 (19.74%), vacAi2 (17.54%), and vacAs2 with 10.96%. Regarding vacAm1 and vacAm2, they were less frequent at 6.14% each. “Handwashing three times or less per day” significantly increased the risk of having vacAi2 allele and H. pylori rRNA16s, with p-values of 0.013 and 0.020, respectively. The consumption of non-tap water increases the risk of carrying the cagA virulence gene. Additionally, H. pylori-positive patients living with more than four (4) people in their household had about two times the risk of having the vacAs1 allele. The present study shows the detection of Helicobacter pylori cagA, vacA subtypes, and babA2 by stool a PCR method in Burkina Faso. The strong association between sanitary habits and virulence factors depicts the composite interaction between ecological factors, gastric mucosa, and bacteria. Therefore, the synergic action of these factors should be considered when aiming for bacterial eradication and gastric pathology cure.
文摘The Helicobacter pylori vacuolating cytotoxin (VacA) is an intracellular, mitochondrial-targeting exotoxin that rapidly causes mitochondrial dysfunction and fragmentation. Although VacA targeting of mitochondria has been reported to alter overall cellular metabolism, there is little known about the consequences of extended exposure to the toxin. Here, we describe studies to address this gap in knowledge, which have revealed that mitochondrial dysfunction and fragmentation are followed by a time-dependent recovery of mitochondrial structure, mitochondrial transmembrane potential, and cellular ATP levels. Cells exposed to VacA also initially demonstrated a reduction in oxidative phosphorylation, as well as increase in compensatory aerobic glycolysis. These metabolic alterations were reversed in cells with limited toxin exposure, congruent with the recovery of mitochondrial transmembrane potential and the absence of cytochrome c release from the mitochondria. Taken together, these results are consistent with a model that mitochondrial structure and function are restored in VacA-intoxicated cells.
文摘目的 vac A 基因编码的蛋白是幽门螺杆菌的一个重要毒力因子,通过空泡化作用损伤上皮细胞.vacA 基因与 Hp 感染者的临床发病有着密切的关系,vacA 的基因型决定毒素蛋白体外表达水平的高低.我们从幽门螺杆菌88022菌株中扩增出vacA 基因毒性相关片段,进行序列测定和序列比较分析,为Hp 的临床检测奠定基础.方法以该菌株总 DNA 为模板,紧随 vacA 基因序列 s 区保守区域的引物(位于316bp～335bp 和1198bp～1218bp)扩增vacA 基因的一个903bp 片段,编码的氨基酸为34～334位,用13amHI 和 Pst Ⅰ双酶切后克隆入 pGEM-3Zf(-)质粒载体,以双脱氧法双向测定目的片段的序列,拼接出该片段的全序列,并与已知的 Hp vacA 基因序列作比较.结果所得序列与 Hp 国际标准株 CCUG17874(GeneBank gi619248)和 NCTCll638(GeneBank gi 495469)的 vacA 基因序列完全一致,氨基酸序列分析和所报道的结果一致.结论构建了 Hp vacA 基因毒性相关片段的重组克隆,为以后的进一步研究奠定了基础.
