Various polymerase chain reaction- (PCR-) based methods with varying positivity rates were designed to detect the Helicobacter pylori babA2 gene. To compare different primer sets, babA2 prevalence was determined in 279 H. pylori-positive pediatric samples using the 832 bp, 139 bp, and 271 bp PCR primer sets, resulting in 34.0%, 51.3%, and 79.6% prevalence of the babA2 gene, respectively. The babA2 status determined using the 832 bp and 139 bp PCR primer sets significantly correlated with bacterial density and activity of inflammation, whereas no such correlations were found using the 271 bp PCR primer set. The 139 and 832 bp PCR primer sets concordantly detected the babA2 gene in 93 cases; however, in comparison to the 832 bp PCR primer set, the 139 bp PCR primer set detected additional 50 babA2 cases, whereas only two 832 bp positive cases were missed. The 271 bp PCR primer set missed 32 babA2 cases that were 832 bp and/or 139 bp PCR positive, but tested solely positive in 109 cases. Interestingly, cloning of a subset of 271 bp PCR positive samples revealed amplification of the babA/B gene chimera. Hence, in our opinion, the 271 bp PCR protocol is not a reliable diagnostic tool for detecting the babA2 gene in children. Our results reaffirm previous observations that the use of certain babA2 PCR primer sets can significantly impact estimation of the prevalence and clinical relevance of the H. pylori babA2 gene in children, suggesting babA2 detection methods should be carefully selected.

中文翻译：

---

儿童幽门螺杆菌babA2基因的流行主要取决于所使用的PCR引物组。

设计了各种具有不同阳性率的基于聚合酶链反应（PCR）的方法来检测幽门螺杆菌babA2基因。为了比较不同的引物组，使用832 bp，139 bp和271 bp PCR引物组在279例幽门螺杆菌阳性儿科样本中确定babA2患病率，得出babA2基因的患病率34.0％，51.3％和79.6％。， 分别。使用832 bp和139 bp PCR引物组确定的babA2状态与细菌密度和炎症活性显着相关，而使用271 bp PCR引物组则未发现这种相关性。139和832 bp PCR引物组一致地检测到babA2基因93例；但是，与832 bp PCR引物组相比，139 bp PCR引物组检测到另外50例babA2病例，而仅漏掉了2 832 bp阳性病例。271 bp PCR引物组错过了832 bp和/或139 bp PCR阳性的32 babA2病例，但仅对109例进行了阳性检测。有趣的是，克隆了271 bp PCR阳性样品的一个子集，发现babA / B基因嵌合体得到了扩增。因此，我们认为，271 bp PCR方案不是检测儿童babA2基因的可靠诊断工具。我们的结果重申了先前的观察结果，即某些babA2的使用PCR引物组可以显着影响儿童幽门螺杆菌babA2基因的流行程度和临床相关性，建议应谨慎选择babA2检测方法。