Vernet V, Philippon A, Madoulet C, Vistelle R, Jaussaud R, Chippaux C
Laboratoire de Bactériologie-Virologie, Faculté de Médecine, Reims, France.
FEMS Microbiol Lett. 1995 Jul 15;130(1):51-7. doi: 10.1016/0378-1097(95)00141-Q.
We examined the presence of two virulence factors in 241 blood isolates of Klebsiella pneumoniae from patients hospitalized during 1989 and 1990 in 7 French hospitals, and 125 blood isolates of Escherichia coli from one hospital. Aerobactin was scored phenotypically and genotypically with an intragenic DNA probe of 2 kb. The mucoid phenotype was assessed by culture on trypticase soy agar and by genotypic analysis (intragenic DNA probe of 235 bp). Only 6% K. pneumoniae isolates were aerobactin-positive with no significant variation according to geographical location while 20% of K. pneumoniae isolates displayed the mucoid phenotype, with a significant variation according to hospital. Aerobactin was always associated with the mucoid phenotype. The frequency of aerobactin production but not mucoid phenotype (14%) was higher among E. coli isolates (48%). They harbored two types of large plasmids. Intraperitoneal injection into mice of 10(3) cfu of K. pneumoniae producing both virulence factors demonstrated that capsular serotype K2 was the more virulent K23 and K28.
我们检测了1989年和1990年期间在法国7家医院住院患者的241株肺炎克雷伯菌血液分离株以及一家医院的125株大肠埃希菌血液分离株中两种毒力因子的存在情况。采用2 kb的基因内DNA探针从表型和基因型上对气杆菌素进行评分。通过在胰蛋白酶大豆琼脂上培养以及基因型分析（235 bp的基因内DNA探针）来评估黏液样表型。仅6%的肺炎克雷伯菌分离株气杆菌素呈阳性，且根据地理位置无显著差异，而20%的肺炎克雷伯菌分离株表现出黏液样表型，根据医院不同存在显著差异。气杆菌素总是与黏液样表型相关。大肠埃希菌分离株中气杆菌素产生频率（48%）高于黏液样表型频率（14%）。它们携带两种类型的大质粒。对同时产生两种毒力因子的肺炎克雷伯菌10³ cfu进行小鼠腹腔注射，结果表明荚膜血清型K2比K23和K28更具毒力。
