临床分离艰难梭菌毒素携带特征研究

目的对医院细菌室送检粪便标本中分离出的艰难梭菌，进行毒素基因以及耐药基因的初步分析。方法将细菌室收集到的112份粪便标本，经选择性厌氧培养，谷氨酸脱氢酶（GDH）以及API 20A 生化条鉴定后，分离出12株艰难梭菌，分别采用PCR的方法检测ItcdA/I和ItcdB/I基因、二元毒素基因，克林霉素抗性基因（IermB/I）。结果12株艰难梭菌中8株为毒素基因阳性，其中ItcdA/Isup+/supItcdB/Isup+/sup为5株，占62.5%；ItcdA/Isup-/supItcdB/Isup+/sup为3株，占37.5%；二元毒素基因均为阴性；耐药基因IermB/I阳性为4株，占50%。结论艰难梭菌ItcdA/Isup-/supItcdB/Isup+/sup毒株所占比例增加，临床单独检测A毒素易造成漏检；艰难梭菌耐药现象值得关注。

Study on toxin characteristics of Clostridium difficile isolated from hospital

Objective To analyze the toxin gene and drug resistance gene of Clostridium difficile isolated from the stool samples sent by hospitals. Methods A total of 12 strains of Clostridium difficile were isolated from 112 stool samples by selective anaerobic culture, glutamic acid dehydrogenase （GDH） and API 20A （bioMerieux） identification, then tcdA、tcdB genes, binary-toxin genes and clindamycin resistance gene （erm B ）were detected by PCR. Results Toxic Clostridium difficile was found in 8 out of 12 strains, 5 strains were tcdA ＋ tcdB＋ （ 62.5% ） ;3 strains were tcdA - tcdB ＋ （37.5%）; all the strains were negative for binary-toxin genes; and 4 out of 8 strains were positive for clindamycin resistance gene （ erm B ） （50%）. Conclusion Proportion of tcdA - tcdB ＋ Clostridium difficile increased, so single toxin A detection might lead to the missed diagnosis of Clostridium difficile-associated diarrhea （CDAD） patients; and more attention should be paid to the drug resistance of Clostridium difficile.