Post-Graduate Program in Dental Clinics, Division of Pediatric Dentistry, Federal University of Rio Grande do Sul - UFRGS, Porto Alegre, Brazil.
Division of Cariology, Department of Preventive and Social Dentistry, Federal University of Rio Grande do Sul - UFRGS, Porto Alegre, Brazil.
Int Endod J. 2018 Nov;51(11):1196-1204. doi: 10.1111/iej.12948. Epub 2018 May 18.
To determine the presence of Prevotella species, the cfxA/cfxA2, blaZ and blaTEM genes associated with resistance to lactamic agents in different oral niches of children with pulp necrosis.
Children with pulp necrosis in primary teeth had samples of saliva, supragingival, pulp chamber and root canal biofilms collected and tested for Prevotella species (P. intermedia, P. nigrescens, P. tannerae) and for beta-lactam resistance genes (cfxA/cfxA2, blaZ and blaTEM). The presence of bacterial DNA was examined through PCR, with a specific primer directed to the 16S rRNA gene. Specific primers were used to detect the Prevotella species and beta-lactam resistance genes. The chi-square test was used to analyse associations between the presence of bacteria and clinical variables. The Cochran's Q test was used to assess whether the proportion of gene detection is the same between different sites.
Thirty-two teeth were sampled from 27 patients with a mean age of 5.5 years (±1.76). The total detection rate of Prevotella strains was 29.1%, 25%, 21.8% and 32.29% in saliva, supragingival, pulp chamber and root canal samples, respectively. P. nigrescens was the most commonly detected species in all oral niches. The previous use of antibiotics was associated with detection of P. nigrescens in saliva (P = 0.03). Pain was associated with the presence of P. nigrescens (P = 0.04) and P. tannerae (P = 0.01) in pulp chamber biofilm. blaTEM was detected in the four oral niches, being more frequent (23.8%) in supragingival biofilm (Cochran's Q test, P = 0.04). The presence of P. intermedia in SB and PC was associated with the detection of blaTEM in saliva (P = 0.04). The cfxA/cfxA2 and blaZ genes were not detected in any of the four oral niches.
The oral cavity of children with pulp necrosis had a variable distribution of Prevotella strains in different niches. Saliva, supragingival biofilm, pulp chamber and root canals of primary teeth with necrotic pulps can harbour resistance genes to beta-lactams agents.
确定坏死性牙髓炎患儿不同口腔部位是否存在与耐β-内酰胺类药物相关的普雷沃菌属种、cfxA/cfxA2、blaZ 和 blaTEM 基因。
采集患有原发性乳牙牙髓坏死儿童的唾液、龈上、牙髓腔和根管生物膜样本，并通过聚合酶链反应（PCR）检测普雷沃菌属种（中间普雷沃菌、黑色普雷沃菌、 Tannerella 普雷沃菌）和β-内酰胺类药物耐药基因（cfxA/cfxA2、blaZ 和 blaTEM）。采用针对 16S rRNA 基因的特异性引物检测细菌 DNA 的存在。使用特异性引物检测普雷沃菌属种和β-内酰胺类药物耐药基因。采用卡方检验分析细菌存在与临床变量之间的相关性。采用 Cochran's Q 检验评估不同部位基因检测比例是否相同。
从 27 名平均年龄为 5.5 岁（±1.76）的患儿中采集了 32 颗牙齿。唾液、龈上、牙髓腔和根管样本中普雷沃菌属种的总检出率分别为 29.1%、25%、21.8%和 32.29%。在所有口腔部位，黑色普雷沃菌是最常见的检出种。唾液中检出黑色普雷沃菌与患儿使用抗生素史相关（P=0.03）。疼痛与牙髓腔生物膜中黑色普雷沃菌（P=0.04）和 Tannerella 普雷沃菌（P=0.01）的存在相关。blaTEM 基因在四个口腔部位均有检出，龈上生物膜中检出率更高（23.8%）（Cochran's Q 检验，P=0.04）。龈下和牙髓腔生物膜中检出中间普雷沃菌与唾液中检出 blaTEM 相关（P=0.04）。cfxA/cfxA2 和 blaZ 基因在四个口腔部位均未检出。
坏死性牙髓炎患儿的口腔内不同部位存在不同普雷沃菌属种分布。坏死性牙髓的乳牙的唾液、龈上生物膜、牙髓腔和根管可携带β-内酰胺类药物耐药基因。
