Koh Tse Hsien, Tan Ai Ling, Tan Mee Lee, Wang Grace, Song Keang Peng
Department of Pathology, Singapore General Hospital, University of Singapore, Singapore.
Pathology. 2007 Aug;39(4):438-42. doi: 10.1080/00313020701444507.
We undertook this study to define the incidence of toxigenic Clostridium difficile in our hospital and to characterise the isolates.
All unformed stool was tested for the presence of Toxin A (TcdA) and Toxin B (TcdB), and cultured for C. difficile. Culture filtrates were also tested for TcdA and TcdB. Detection of tcdA and tcdB genes was carried out for A(-)B(+) strains by polymerase chain reaction (PCR).The minimum inhibitory concentrations (MICs) of metronidazole, vancomycin and clindamycin for all isolates were tested using the Etest. PCR ribotyping was carried out on all isolates.
The incidence of Clostridium difficile associated disease (CDAD) was 3.2 cases per 1000 admissions or discharges and 53.8 cases per 100 000 patient days. Most cases occurred in renal and haematology patients. CDAD was more common in patients aged over 50 years and of male gender. The Indian population was under-represented. Fourteen (11.8%) isolates were A(-)B(+). All strains were susceptible to metronidazole but one strain showed intermediate resistance to vancomycin. Only 12.8% of the isolates were susceptible to clindamycin. Thirty-five isolates had PCR ribotype A, of which 29 (83%) had a clindamycin MIC >256 mg/L. Thirty-three had PCR ribotype B, of which only one (3%) had a clindamycin MIC >256 mg/L. The 14 A(-)B(+) strains were all PCR ribotype C, and had a range of MICs for clindamycin from 2 to >256 mg/L.
The incidence of CDAD in our hospital is relatively low. Isolates remain susceptible to metronidazole and vancomycin.
我们开展本研究以确定我院产毒艰难梭菌的发病率并对分离株进行特征分析。
对所有不成形粪便检测毒素A（TcdA）和毒素B（TcdB）的存在情况，并进行艰难梭菌培养。培养滤液也检测TcdA和TcdB。通过聚合酶链反应（PCR）对A（-）B（+）菌株进行tcdA和tcdB基因检测。使用Etest检测所有分离株对甲硝唑、万古霉素和克林霉素的最低抑菌浓度（MIC）。对所有分离株进行PCR核糖体分型。
艰难梭菌相关疾病（CDAD）的发病率为每1000例入院或出院患者中有3.2例，每100000患者日中有53.8例。大多数病例发生在肾脏和血液科患者中。CDAD在50岁以上男性患者中更为常见。印度人群代表性不足。14株（11.8%）分离株为A（-）B（+）。所有菌株对甲硝唑敏感，但有1株对万古霉素呈中度耐药。仅12.8%的分离株对克林霉素敏感。35株分离株具有PCR核糖体分型A，其中29株（83%）的克林霉素MIC>256 mg/L。33株具有PCR核糖体分型B，其中只有1株（3%）的克林霉素MIC>256 mg/L。14株A（-）B（+）菌株均为PCR核糖体分型C，克林霉素MIC范围为2至>256 mg/L。
我院CDAD的发病率相对较低。分离株对甲硝唑和万古霉素仍敏感。
