Dupont Chloé, Jumas-Bilak Estelle, Michon Anne-Laure, Chiron Raphaël, Marchandin Hélène
Université Montpellier, UMR5569 Hydrosciences Montpellier, Equipe Pathogènes Hydriques, Santé, Environnements, UFR des Sciences Pharmaceutiques et Biologiques, Montpellier, France.
Centre Hospitalier Régional Universitaire de Montpellier, Hôpital Saint-Eloi, Laboratoire d'Hygiène hospitalière, Montpellier, France.
J Clin Microbiol. 2016 Dec 28;55(1):206-215. doi: 10.1128/JCM.01843-16. Print 2017 Jan.
Chronic colonization by opportunistic environmental bacteria is frequent in the airways of cystic fibrosis (CF) patients. Studies of Pseudomonas aeruginosa evolution during persistence have highlighted the emergence of pathoadaptive genotypes and phenotypes, leading to complex and diversified inpatient colonizing populations also observed at the intraspecimen level. Such diversity, including heterogeneity in resistance profiles, has been considered an adaptive strategy devoted to host persistence. Longitudinal genomic diversity has been shown for the emergent opportunistic pathogen Achromobacter, but phenotypic and genomic diversity has not yet been studied within a simple CF sputum sample. Here, we studied the genomic diversity and antimicrobial resistance heterogeneity of 132 Achromobacter species strains (8 to 27 strains of identical or distinct colonial morphotypes per specimen) recovered from the sputum samples of 9 chronically colonized CF patients. We highlighted the high within-sample and within-morphotype diversity of antimicrobial resistance (disk diffusion) and genomic (pulsed-field gel electrophoresis) profiles. No sputum sample included strains with identical pulsotypes or antibiotic susceptibility patterns. Differences in clinical categorization were observed for the 9 patients and concerned 3 to 11 antibiotics, including antibiotics recommended for use against Achromobacter Within-sample antimicrobial resistance heterogeneity, not predictable from colonial morphology, suggested that it may represent a selective advantage against antibiotics in an Achromobacter persisting population and potentially compromise the antibiotic management of CF airway infections.
在囊性纤维化（CF）患者的气道中，机会性环境细菌的慢性定植很常见。对铜绿假单胞菌在持续存在过程中的进化研究突出了致病适应性基因型和表型的出现，这导致在标本内水平也观察到复杂多样的住院患者定植菌群。这种多样性，包括耐药谱的异质性，被认为是一种致力于在宿主体内持续存在的适应性策略。已证明新兴的机会性病原体无色杆菌存在纵向基因组多样性，但尚未在简单的CF痰液样本中研究其表型和基因组多样性。在此，我们研究了从9例长期定植的CF患者痰液样本中分离出的132株无色杆菌菌株（每个标本8至27株相同或不同菌落形态型的菌株）的基因组多样性和抗菌药物耐药性异质性。我们强调了抗菌药物耐药性（纸片扩散法）和基因组（脉冲场凝胶电泳）谱在样本内和形态型内的高度多样性。没有痰液样本包含具有相同脉冲型或抗生素敏感性模式的菌株。在这9例患者中观察到临床分类的差异，涉及3至11种抗生素，包括推荐用于对抗无色杆菌的抗生素。样本内抗菌药物耐药性异质性无法从菌落形态预测，这表明它可能代表了无色杆菌持续存在群体对抗生素的一种选择优势，并可能影响CF气道感染的抗生素管理。
