Camacho-Ortiz Adrián, López-Barrera Daniel, Hernández-García Raúl, Galván-De Los Santos Alejandra M, Flores-Treviño Samantha M, Llaca-Díaz Jorge M, Maldonado-Garza Héctor J, Bosques-Padilla Francisco J, Garza-González Elvira
Servicio de Infectología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
PLoS One. 2015 Apr 27;10(4):e0122627. doi: 10.1371/journal.pone.0122627. eCollection 2015.
Clostridium difficile NAP1/ribotype 027 is associated with severe disease and high mortality rates. Our aim was to determine the prevalence of NAP1/ribotype 027 among C. difficile isolates in a tertiary care hospital, and review the main clinical data.
We included 106 stool samples from 106 patients. Samples were tested for A&B toxins and were cultured on CCFA agar. The genes tcdA, tcdB, tcdC, cdtA, and cdtB were amplified using PCR in clinical isolates. The tcdA 3'-end deletion analysis, PCR-ribotyping, and pulsed-field gel electrophoresis (PFGE) were also performed. Stool samples that were positive for culture were tested by the GeneXpert C. difficile assay. Clinical data were collected.
Thirty-six patients tested positive for A&B toxins; and 22 patients had positive culture for C. difficile, 14 of which tested positive for the A&B toxins and all 22 patients tested positive by the GeneXpert C. difficile assay. Risk factors included an average hospital stay of 16.1 days prior to toxin detection, average antibiotic use for 16.2 days, and a median of 3 antibiotics used. The 30-day crude mortality rate was 8.4%. Six of the 22 patients died, and 3 of those deaths were directly attributed to C. difficile infection. The majority of isolates, 90.9% (20/22), carried genes tcdB, tcdA, cdtA, and cdtB; and these strains carried the corresponding downregulator gene tcdC, with an 18-bp deletion. PFGE was performed on 17 isolates, and one main pattern was observed. Analysis of the ribotyping data showed similar results.
The above findings represent the clonal spread of C. difficile in our institution, which mainly includes the NAP1/027 strain. This is the first report of C. difficile ribotype NAP1/027 in Mexico.
艰难梭菌NAP1/核糖体分型027与严重疾病及高死亡率相关。我们的目的是确定一家三级护理医院中艰难梭菌分离株中NAP1/核糖体分型027的流行情况，并回顾主要临床数据。
我们纳入了106例患者的106份粪便样本。对样本进行A&B毒素检测，并在CCFA琼脂上培养。使用PCR对临床分离株中的tcdA、tcdB、tcdC、cdtA和cdtB基因进行扩增。还进行了tcdA 3'-末端缺失分析、PCR核糖体分型和脉冲场凝胶电泳（PFGE）。对培养阳性的粪便样本进行艰难梭菌基因Xpert检测。收集临床数据。
36例患者A&B毒素检测呈阳性；22例患者艰难梭菌培养呈阳性，其中14例A&B毒素检测呈阳性，所有22例患者通过艰难梭菌基因Xpert检测均呈阳性。危险因素包括毒素检测前平均住院16.1天、平均使用抗生素16.2天以及使用抗生素中位数为3种。30天粗死亡率为8.4%。22例患者中有6例死亡，其中3例死亡直接归因于艰难梭菌感染。大多数分离株（90.9%，20/22）携带tcdB、tcdA、cdtA和cdtB基因；这些菌株携带相应的下调调节基因tcdC，有一个18bp的缺失。对17株分离株进行了PFGE，观察到一种主要模式。核糖体分型数据分析显示了相似的结果。
上述发现代表了艰难梭菌在我们机构中的克隆传播，主要包括NAP1/027菌株。这是墨西哥首次关于艰难梭菌核糖体分型NAP1/027的报告。
