Millette Guillaume, Langlois Jean-Philippe, Brouillette Eric, Frost Eric H, Cantin André M, Malouin François
Centre d'Étude et de Valorisation de la Diversité Microbienne, Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.
Département de Microbiologie et d'Infectiologie, Faculté de Médecine et de Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.
Front Microbiol. 2019 Dec 13;10:2880. doi: 10.3389/fmicb.2019.02880. eCollection 2019.
and are prevalent lung pathogens in cystic fibrosis (CF). Whereas co-infection worsens the clinical outcome, prototypical strains are usually antagonistic . We sought to resolve the discrepancy between these and observations. , growth kinetics for co-cultures of co-isolates from CF patients showed that not all strains affected viability. On solid media, slow-growing colonies were visualized around some strains whether or not viability was reduced in liquid co-cultures. The interactions were then characterized in a mouse lung infection model. Lung homogenates were plated on selective media allowing colony counts of either bacterium. Overall, 35 and 10 strains (clinical, reference, and mutant strains), for a total of 200 co-infections, were evaluated. We observed that colonization of lung tissues was promoted by and even by strains showing antagonism . Promotion was proportional to the extent of colonization, but no correlation was found with the degree of myeloperoxidase quantification (as marker of inflammation) or with specific virulence-associated factors using known mutant strains of and . On the other hand, significantly increased the expression of two possible cell receptors for , ., ICAM-1 and ITGA-5 (marker for integrin αβ) in lung tissue, while mono-infections by did not. This study provides insights on polymicrobial interactions that may influence the progression of CF-associated pulmonary infections.
和是囊性纤维化（CF）中常见的肺部病原体。虽然合并感染会使临床结果恶化，但典型菌株通常具有拮抗作用。我们试图解决这些观察结果之间的差异。首先，对CF患者共分离株的共培养物的生长动力学研究表明，并非所有菌株都会影响的生存能力。在固体培养基上，无论在液体共培养中生存能力是否降低，在一些菌株周围都能看到生长缓慢的菌落。然后在小鼠肺部感染模型中对这种相互作用进行了表征。将肺匀浆接种在选择性培养基上，以便对任何一种细菌进行菌落计数。总共评估了35株和10株（临床菌株、参考菌株和突变菌株），共200次合并感染。我们观察到，的定殖会促进肺部组织的定殖，甚至是那些表现出拮抗作用的菌株也会如此。促进作用与的定殖程度成正比，但在使用已知的和突变菌株时，未发现与髓过氧化物酶定量（作为炎症标志物）或特定毒力相关因子有相关性。另一方面，显著增加了肺组织中两种可能的细胞受体的表达，即ICAM-1和ITGA-5（整合素αβ的标志物），而单独感染则不会。这项研究为可能影响CF相关肺部感染进展的多微生物相互作用提供了见解。
