title: Effect of Anaerobiasis or Hypoxia on Pseudomonas aeruginosa Inhibition of Aspergillus fumigatus Biofilm.
abstract: Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) are the major bacterial and fungal pathogens in the airways of cystic fibrosis (CF) patients. This is likely related to their ability to form biofilms. Both microbes have been associated with CF disease progression. The interplay between these two pathogens has been studied under aerobic conditions, though accumulating data indicates that much of the CF airway is hypoxic or anaerobic. We studied the microbial interaction in these latter environments. Pa is an aggressor against Af forming biofilm or as established Af biofilm, whether Pa is cultivated in aerobic, hypoxic, or anaerobic conditions, or tested in aerobic or hypoxic conditions. Pa cells are generally more effective than planktonic or biofilm culture filtrates. Pa growth is less in anaerobic conditions, and filtrates less effective after anaerobic or hypoxic growth, or against hypoxic Af. These, and other comparisons shown, indicate that Pa would be less effective in such environments, as would be the case in a CF mucus plug. These observations would explain why Pa becomes established in CF airways before Af, and why Af may persist during disease progression.
authors.affiliation: California Institute for Medical Research, 2260 Clove Dr., San Jose, CA, 95128, USA.|Division of Infectious Disease and Geographic Medicine, Department of Medicine, School of Medicine, Stanford University, Stanford, CA, 94305, USA.|Department of Biotechnology, Guru Ghasidas Vishwavidyalaya (A Central University), C.G., Bilaspur, 495009, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Anand
authors.affiliation: California Institute for Medical Research, 2260 Clove Dr., San Jose, CA, 95128, USA.|Division of Infectious Disease and Geographic Medicine, Department of Medicine, School of Medicine, Stanford University, Stanford, CA, 94305, USA.
authors.forename: Karl V
authors.initials: KV
authors.lastname: Clemons
authors.affiliation: California Institute for Medical Research, 2260 Clove Dr., San Jose, CA, 95128, USA. stevens@stanford.edu.|Division of Infectious Disease and Geographic Medicine, Department of Medicine, School of Medicine, Stanford University, Stanford, CA, 94305, USA. stevens@stanford.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Stevens
mesh_terms: D000693:Anaerobiosis; D001232:Aspergillus fumigatus / Q000502:physiology*; D018441:Biofilms; D006801:Humans; D056265:Microbial Interactions; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000502:physiology*
chemical_list: D010100:Oxygen
keywords: Anaerobiasis; Aspergillus; Cystic fibrosis; Hypoxia; Intermicrobial inhibition; Pseudomonas