aeruginosa strains associated with acute LRTI differ from those that chronically colonize the airways of CF patients 16, 17. Transition from occasional colonization into persistent respiratory infections could be facilitated, among many other factors, by the ability of pathogenic bacteria to form biofilms and tolerate antibiotic treatments 13, 15. aeruginosa have been widely reported during the course of chronic pulmonary diseases, such as CF and chronic obstructive pulmonary disease (COPD) 14, little has been investigated regarding these interactions in acute LRTI or bronchial colonization. Due to the intrinsic mechanisms of adaptation, survival and resistance to multiple classes of antibiotics 9, 10, their strain- and environment-specific interactions could play an important role in disease progression, the antimicrobial therapy choice and the clinical outcome 11, 12, 13. aeruginosa have been co-isolated, disease outcomes have been seen more severe compared to single species infections 1. In biofilm-related infections, such as the ones occurring in cystic fibrosis (CF) or chronic wounds, in which S. Both microorganisms are among the most common in the pulmonary microbiota displaying a range of cooperative and competitive interactions, and their co-isolation has been observed in a wide range of airway diseases 8. aeruginosa are two of the major MDR nosocomial pathogens 4 commonly associated with lower respiratory tract infections (LRTI) in diverse clinical settings 5, 6, 7. Indeed the biofilm environment favors the development of antimicrobial resistance through a variety of mechanisms 3 and thus facilitates the emergence of multidrug resistant (MDR) microorganisms. It has been postulated that the most common lifestyle adopted by bacteria in nature is to grow in biofilm mode where the microbial community protects itself from antimicrobial agents, including both drugs and host defenses. Further, an important number of human infections are associated with biofilms development, especially those associated with indwelling medical devices such as orotracheal tubes and urinary catheters 1, 2. The concern about polymicrobial infections has been increasing, especially regarding the biofilm environment, where Staphylococcus aureus and Pseudomonas aeruginosa, members of the microbiota and potential pathogens, interact with each other 1. aureus by studying strains isolated during acute infection. This work contributes to understanding the complex interspecies interactions between P. Finally, co-infection in the acute infection model in Galleria mellonella larvae showed an additive effect only in the co-isolated pair in which P. Under these conditions, key genes controlled by quorum sensing were differentially regulated in both species in an isolate-dependent manner. Co-culture in a medium that mimics respiratory mucus promoted coexistence and favored mixed microcolony formation within biofilms. aureus did not impair biofilm formation and stimulated swarming motility in P. aeruginosa exoproducts affected biofilm formation and reduced growth in vitro in its S. Despite this, and the clinical origin of the strains, some interactions were common between some co-isolated pairs. The genetic and phenotypic diversity between the isolates was high making the interactions detected strain-specific. Dual species interactions in co-isolated pairs of Staphylococcus aureus and Pseudomonas aeruginosa from patients with tracheobronchitis or bronchial colonization were examined.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |