Martirosian Gayane, Szczesny Adam, Silva Joseph
Department of Medical Microbiology, Medical University of Silesia, 18 Medykow Str., Katowice 40-752, Poland.
Anaerobe. 2005 Oct;11(5):258-61. doi: 10.1016/j.anaerobe.2005.02.003. Epub 2005 Apr 21.
Clostridium difficile strains are known as etiological agents of pseudomembranous colitis (PMC), antibiotic-associated diarrhea (AAC) and colitis (AAC) and hospital-acquired infections. The aim of this study was to determine the frequency of C. difficile infection among patients in the emergency room and to compare isolated strains by phenotypic and genotypic characteristics. During a period of 11 months, 56 stool samples taken from diarrheic patients hospitalized in the emergency room of the Medical Center UC Davis and 14 environmental samples were cultured for isolation of C. difficile strains. Eighteen C. difficile strains were isolated from stool samples cultured on selective TCCCA plates and 5 strains from environmental samples using Rodac plates. Eleven toxigenic (TcdA+/TcdB+), 6 non-toxigenic (TcdA-/TcdB-) and unique toxin A-negative/toxin B-positive (TcdA-/TcdB+) C. difficile strains were detected among patients' isolates and 3 toxigenic and 2 non-toxigenic strains-among environmental samples. The majority of C. difficile-positive patients were treated previously by antibiotics. Four strains isolated from patients' fecal samples and one strain isolated from the environment demonstrated high-level resistance to erythromycin and clindamycin (MIC >256mug/mL). The results obtained by AP-PCR and PCR-ribotyping revealed genetic heterogeneity among the strains isolated from patients' fecal samples. However, similarity was observed among environmental strains and strains isolated from patients' fecal samples. Considering the importance of emergency room patients as a potential source of C. difficile strains, it appears to be important examine these patients for C. difficile before transfer to the other hospital units.
艰难梭菌菌株是假膜性结肠炎（PMC）、抗生素相关性腹泻（AAC）和结肠炎（AAC）以及医院获得性感染的病原体。本研究的目的是确定急诊室患者中艰难梭菌感染的频率，并通过表型和基因型特征比较分离出的菌株。在11个月的时间里，对从加州大学戴维斯分校医疗中心急诊室住院的腹泻患者采集的56份粪便样本和14份环境样本进行培养，以分离艰难梭菌菌株。使用选择性TCCCA平板从粪便样本中分离出18株艰难梭菌菌株，使用Rodac平板从环境样本中分离出5株。在患者分离株中检测到11株产毒素（TcdA+/TcdB+）、6株不产毒素（TcdA-/TcdB-）和独特的毒素A阴性/毒素B阳性（TcdA-/TcdB+）艰难梭菌菌株，在环境样本中检测到3株产毒素和2株不产毒素菌株。大多数艰难梭菌阳性患者之前接受过抗生素治疗。从患者粪便样本中分离出的4株菌株和从环境中分离出的1株菌株对红霉素和克林霉素表现出高水平耐药（MIC>256μg/mL）。通过AP-PCR和PCR-核糖体分型获得的结果显示，从患者粪便样本中分离出的菌株之间存在遗传异质性。然而，在环境菌株和从患者粪便样本中分离出的菌株之间观察到相似性。考虑到急诊室患者作为艰难梭菌菌株潜在来源的重要性，在将这些患者转移到其他医院科室之前对其进行艰难梭菌检测似乎很重要。
