Ribes Sandra, Taberner Ferran, Cabellos Carmen, Tubau Fe, Ardanuy Carmen, Gerber Joachim, Liñares Josefina, Nau Roland, Gudiol Francesc
Laboratory of Experimental Infection, Infectious Diseases Department, Hospital Universitari de Bellvitge - IDIBELL - University of Barcelona, Feixa Llarga s/n, 08907 Hospitalet de Llobregat, Spain.
Microbes Infect. 2008 Feb;10(2):129-34. doi: 10.1016/j.micinf.2007.10.014. Epub 2007 Nov 4.
We used a rabbit model to assess the effects of capsular serotype, genetic background and beta-lactam resistance on the course and severity of experimental meningitis. Meningitis was induced by five pneumococcal strains belonging to five different clones with known invasive potential: two serotype 3 strains (ST260(3) and Netherlands(3)-31 clones) and three serotype 23F strains with different beta-lactam susceptibility patterns (Spain(23F)-1 clone, Tennessee(23F)-4 clone and a double locus variant of the Tennessee(23F)-4 clone). Major differences in secondary bacteremia and mortality rates were observed between serotypes 3 and 23F, as were divergences in the CSF lactate, protein and lipoteichoic-teichoic acid concentrations. Minor differences in the CSF-induced inflammatory response were found among strains belonging to the same serotype. Our results suggest that capsular serotype might be the main factor determining the course and severity of pneumococcal meningitis and genetic background contributes to a lesser extent. The acquisition of beta-lactam resistance does not reduce the virulence of the invasive clones. Since five strains belonging to two serotypes were studied, our findings have to be confirmed with other pneumococcal serotypes.
我们使用兔模型评估荚膜血清型、遗传背景和β-内酰胺耐药性对实验性脑膜炎病程和严重程度的影响。脑膜炎由属于五个具有已知侵袭潜力的不同克隆的五种肺炎球菌菌株诱发：两种3血清型菌株（ST260(3)和荷兰(3)-31克隆）以及三种具有不同β-内酰胺敏感性模式的23F血清型菌株（西班牙(23F)-1克隆、田纳西(23F)-4克隆以及田纳西(23F)-4克隆的双位点变体）。在3血清型和23F血清型之间观察到继发性菌血症和死亡率的主要差异，脑脊液乳酸盐、蛋白质和脂磷壁酸-磷壁酸浓度也存在差异。在属于同一血清型的菌株之间发现脑脊液诱导的炎症反应存在微小差异。我们的结果表明，荚膜血清型可能是决定肺炎球菌性脑膜炎病程和严重程度的主要因素，而遗传背景的作用较小。获得β-内酰胺耐药性并不会降低侵袭性克隆的毒力。由于研究了属于两种血清型的五种菌株，我们的发现必须用其他肺炎球菌血清型进行验证。
