Molecular detection of multiple emerging pathogens in sputa from cystic fibrosis patients

Abstract

Background: There is strong evidence that culture-based methods detect only a small proportion of bacteria present in the respiratory tracts of cystic fibrosis (CF) patients.Methodology/Principal Findings: Standard microbiological culture and phenotypic identification of bacteria in sputa from CF patients have been compared to molecular methods by the use of 16S rDNA amplification, cloning and sequencing. Twenty-five sputa from CF patients were cultured that yield 33 isolates (13 species) known to be pathogens during CF. For molecular cloning, 760 clones were sequenced (7.263.9 species/sputum), and 53 different bacterial species were identified including 16 species of anaerobes (30%). Discrepancies between culture and molecular data were numerous and demonstrate that accurate identification remains challenging. New or emerging bacteria not or rarely reported in CF patients were detected including Dolosigranulum pigrum, Dialister pneumosintes, and Inquilinus limosus.Conclusions/Significance: Our results demonstrate the complex microbial community in sputa from CF patients, especially anaerobic bacteria that are probably an underestimated cause of CF lung pathology. Metagenomic analysis is urgently needed to better understand those complex communities in CF pulmonary infections.

Assessment of Airway Microbiota and Inflammation in Cystic Fibrosis Using Multiple Sampling Methods

“…Pseudomonas aeruginosa and Staphylococcus aureus are the bacteria most frequently implicated in CF airway infection. However, culture-independent molecular approaches have detected far more complex microbiota in CF airways (2)(3)(4)(5)(6)(7)(8)(9). Nontraditional bacteria from CF airway specimens, particularly anaerobes (e.g., Prevotella, Actinomyces, Veillonella, and Rothia), have been identified by molecular approaches and isolated using anaerobic cultures.…”

Phlyctenular Keratoconjunctivitis Associated withDolosigranulum pigrum

“…The inciting antigen could be specific to one microbe or shared by several. [1][2][3][4][5][8][9][10] In this patient, phlyctenular keratoconjunctivitis arose against the backdrop of asthma and environmental allergies. Asthma, allergies, and phlyctenulosis have immunologic components that are central to their pathogeneses.…”

“…The organism has emerged as a potential pathogen in humans and has been identified in a broad spectrum of diseases, including nosocomial pneumonia and 9 and cystic fibrosis pneumonia. 10 Ocular involvement of D. pigrum has been reported in cases of a neurotrophic cornea, 11 blepharitis, 12 keratitis, 13 and bacterial conjunctivitis.…”

Le résistome pulmonaire

“…[11]. Avec l'âge, la diversité microbienne diminue et l'installation de P. aeruginosa apparaît corrélée à la dégra-dation fonctionnelle respiratoire, ainsi qu'à la prépondérance de bactéries multivoire pan-résistantes.…”