摘要

      目标：
      本研究的目的是确定墨西哥原发性感染或治疗后疾病根管样本中编码对三组抗菌药物耐药基因的流行率。
      方法：
      共有64名因原发感染或治疗后疾病需要根管治疗的受试者被纳入本横断面分析研究。取根管标本，分离DNA。对6个耐药基因（ARGs）和7个细菌类群（5属2种）进行了特异性引物分析。在适当的情况下，采用学生t检验、x2检验和Fisher精确检验来检测统计差异。
       结果：
       与原发感染组相比，治疗后疾病组中blaTEM-1、ermC和tetM基因的检出率更高。除肠球菌属和牙髓卟啉单胞菌在治疗后疾病组中发现的频率明显较高外，两组中评估细菌的发生率相似。观察发现，治疗后疾病组存在较多的精氨酸。最常见的ARG是tetW，而tetQ和cfxA在任何情况下都没有检测到。就细菌分类而言，100%的样本中存在梭杆菌属，而在任何样本中均未观察到牙龈卟啉单胞菌。
       结论：
       在所有病例中，至少检测到一个ARG；此外，32.8%的样本对四个ARG呈阳性，54.7%的样本对三个ARG呈阳性，9.4%的样本对两个ARG呈阳性，只有3.1%的样本对一个ARG呈阳性。这表明在这些根管样本中ARGs的高患病率和多样性。

OBJECTIVES:

The aim of this study was to identify the prevalence of genes encoding resistance to three groups of antimicrobial agents in root canal samples from primary infection or post-treatment disease in Mexico.

METHODS:

A total of 64 subjects requiring root canal treatment because of primary infection or post-treatment disease were enrolled in this cross-sectional analytical study. Root canal samples were obtained and DNA was isolated. Specific primers for six antimicrobial resistance genes (ARGs) and seven bacterial taxa (five genera and two species) were used. Student's t-test, χ² test and Fisher's exact test were applied where appropriate to detect statistical differences.

RESULTS:

The bla_TEM-1, ermC and tetM genes were found more frequently in the post-treatment disease group compared with the primary infection group. The occurrence of assessed bacteria was similar in both groups, except for Enterococcus spp. and Porphyromonas endodontalis, which were found at a significantly higher frequency in the post-treatment disease group. It was observed that the post-treatment disease group harboured more ARGs. The most frequent ARG was tetW, whereas tetQ and cfxA were not detected in any case. With respect to bacterial taxa, Fusobacterium spp. was present in 100% of samples, whereas Porphyromonas gingivalis was not observed in any of the samples.

CONCLUSIONS:

At least one ARG was detected in all cases; moreover, 32.8% of samples were positive for four ARGs, 54.7% for three ARGs, 9.4% for two ARGs and only 3.1% for one ARG. This indicates a high prevalence and diversity of ARGs in these root canal samples

       https://www.sciencedirect.com/science/article/abs/pii/S221371651830095X?via%3Dihub