Eckert C, Emirian A, Le Monnier A, Cathala L, De Montclos H, Goret J, Berger P, Petit A, De Chevigny A, Jean-Pierre H, Nebbad B, Camiade S, Meckenstock R, Lalande V, Marchandin H, Barbut F
Laboratoire associé « Clostridium difficile », Hôpital Saint Antoine, Assistance Publique-Hôpitaux de Paris, France ; UPMC Univ Paris VI, GRC n°2, Epidiff, France.
Laboratoire de Bactériologie, Virologie, Hygiène, Hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Créteil, France.
New Microbes New Infect. 2014 Nov 8;3:12-7. doi: 10.1016/j.nmni.2014.10.003. eCollection 2015 Jan.
Clostridium difficile causes antibiotic-associated diarrhoea and pseudomembranous colitis. The main virulence factors of C. difficile are the toxins A (TcdA) and B (TcdB). A third toxin, called binary toxin (CDT), can be detected in 17% to 23% of strains, but its role in human disease has not been clearly defined. We report six independent cases of patients with diarrhoea suspected of having C. difficile infection due to strains from toxinotype XI/PCR ribotype 033 or 033-like, an unusual toxinotype/PCR ribotype positive for CDT but negative for TcdA and TcdB. Four patients were considered truly infected by clinicians and were specifically treated with oral metronidazole. One of the cases was identified during a prevalence study of A(-)B(-)CDT(+) strains. In this study, we screened a French collection of 220 nontoxigenic strains and found only one (0.5%) toxinotype XI/PCR ribotype 033 or 033-like strain. The description of such strains raises the question of the role of binary toxin as a virulence factor and could have implications for laboratory diagnostics that currently rarely include testing for binary toxin.
艰难梭菌可引起抗生素相关性腹泻和假膜性结肠炎。艰难梭菌的主要毒力因子是毒素A（TcdA）和毒素B（TcdB）。第三种毒素称为二元毒素（CDT），在17%至23%的菌株中可检测到，但其在人类疾病中的作用尚未明确界定。我们报告了6例独立病例，这些腹泻患者疑似因毒素型XI/PCR核糖体分型033或033样菌株感染艰难梭菌，该毒素型/PCR核糖体分型不常见，CDT呈阳性，但TcdA和TcdB呈阴性。4例患者被临床医生判定为真正感染，并接受了口服甲硝唑的特异性治疗。其中1例病例是在A（-）B（-）CDT（+）菌株的患病率研究中发现的。在本研究中，我们对法国收集的220株无毒力菌株进行了筛查，仅发现1株（0.5%）毒素型XI/PCR核糖体分型033或033样菌株。对此类菌株的描述引发了关于二元毒素作为毒力因子作用的问题，并且可能对目前很少包括二元毒素检测的实验室诊断产生影响。
