Hirata R, Pereira G A, Filardy A A, Gomes D L R, Damasco P V, Rosa A C P, Nagao P E, Pimenta F P, Mattos-Guaraldi A L
Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro.
Braz J Med Biol Res. 2008 Nov;41(11):986-91. doi: 10.1590/s0100-879x2008001100007.
Invasive diseases caused by Corynebacterium diphtheriae have been described increasingly. Several reports indicate the destructive feature of endocarditis attributable to nontoxigenic strains. However, few reports have dealt with the pathogenicity of invasive strains. The present investigation demonstrates a phenotypic trait that may be used to identify potentially invasive strains. The study also draws attention to clinical and microbiological aspects observed in 5 cases of endocarditis due to C. diphtheriae that occurred outside Europe. Four cases occurred in female school-age children (7-14 years) treated at different hospitals in Rio de Janeiro, Brazil. All patients developed other complications including septicemia, renal failure and/or arthritis. Surgical treatment was performed on 2 patients for valve replacement. Lethality was observed in 40% of the cases. Microorganisms isolated from 5 blood samples and identified as C. diphtheriae subsp mitis (N = 4) and C. diphtheriae subsp gravis (N = 1) displayed an aggregative adherence pattern to HEp-2 cells and identical one-dimensional SDS-PAGE protein profiles. Aggregative-adhering invasive strains of C. diphtheriae showed 5 distinct RAPD profiles. Despite the clonal diversity, all 5 C. diphtheriae invasive isolates seemed to display special bacterial adhesive properties that may favor blood-barrier disruption and systemic dissemination of bacteria. In conclusion, blood isolates from patients with endocarditis exhibited a unique adhering pattern, suggesting a pathogenic role of aggregative-adhering C. diphtheriae of different clones in endocarditis. Accordingly, the aggregative-adherence pattern may be used as an indication of some invasive potential of C. diphtheriae strains.
由白喉棒状杆菌引起的侵袭性疾病报道日益增多。几份报告指出了非产毒株所致心内膜炎的破坏性特征。然而，关于侵袭性菌株致病性的报道较少。本研究证实了一种可用于识别潜在侵袭性菌株的表型特征。该研究还关注了在欧洲以外发生的5例白喉棒状杆菌所致心内膜炎的临床和微生物学方面。4例发生在巴西里约热内卢不同医院接受治疗的学龄女童（7 - 14岁）。所有患者均出现了包括败血症、肾衰竭和/或关节炎在内的其他并发症。2例患者接受了瓣膜置换手术。40%的病例出现死亡。从5份血样中分离出并鉴定为缓症白喉棒状杆菌亚种（4株）和重型白喉棒状杆菌亚种（1株）的微生物对HEp - 2细胞呈现聚集性黏附模式，且一维SDS - PAGE蛋白谱相同。白喉棒状杆菌的聚集性黏附侵袭菌株显示出5种不同的随机扩增多态性DNA（RAPD）图谱。尽管存在克隆多样性，但所有5株白喉棒状杆菌侵袭性分离株似乎都表现出特殊的细菌黏附特性，这可能有利于破坏血屏障和细菌的全身播散。总之，心内膜炎患者的血培养分离株呈现出独特的黏附模式，提示不同克隆的聚集性黏附白喉棒状杆菌在感染性心内膜炎中具有致病作用。因此，聚集性黏附模式可作为白喉棒状杆菌菌株具有一定侵袭潜力的指标。
