Streptococcus pneumoniae forms surface-attached communities in the middle ear of experimentally infected chinchillas
Sean D Reid1, Wenzhou Hong, Kristin E Dew
1Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
Background:
Streptococcus pneumoniae (pneumococcus) causes respiratory and systemic infections that are a major public health problem worldwide. It has been postulated that pneumococci persist in vivo in biofilm communities.
Methods:
In this study, we analyzed whether pneumococci form biofilms in vivo, and if so, whether biofilms correlated with bacterial persistence. Chinchillas were infected with S. pneumoniae TIGR4 and euthanized at varying times after infection, after which the superior ear bullae were excised and examined by culture and microscopy.
Results:
Dense material, resembling the biofilms of other otitis media pathogens, was visible in the middle ear as late as 12 days after infection. Scanning electron microscopy revealed bacteria within an electron-dense matrix, similar to pneumococcal biofilms formed in vitro. Viability staining revealed groups of viable diplococci, as well as viable and nonviable host cells, attached to a fibrous matrix that was positive when stained with propidium iodide. Cryosections of biofilms were treated with polyclonal antibodies against the pneumococcal surface components pneumococcal surface protein A family 2, pneumococcal surface protein C, choline-binding protein, and neuraminidase, coupled with appropriate secondary antibody conjugates. Immunofluorescent staining showed the presence of pneumococcal communities within the material recovered from the middle ear chamber.
Conclusions:
On the basis of these data, we conclude that pneumococci form biofilms in vivo and that this process may be intertwined with the formation of neutrophil extracellular traps. These findings provide new insights into the potential causes of antibiotic treatment failure and bacterial persistence in chronic pneumococcal otitis media.
Insights
Streptococcus pneumoniae forms biofilms in vivo, potentially explaining antibiotic treatment failure in chronic otitis media. This study observed these bacterial communities in chinchilla middle ears, linking biofilms to persistent infections.
Area of Science:
- Microbiology
- Infectious Diseases
- Otolaryngology
Background:
- Streptococcus pneumoniae (pneumococcus) is a significant global pathogen causing respiratory and systemic infections.
- Pneumococcal persistence in vivo has been hypothesized to involve biofilm communities.
Purpose of the Study:
- To investigate whether pneumococci form biofilms in vivo.
- To determine if these in vivo biofilms correlate with bacterial persistence.
Main Methods:
- Chinchillas were infected with S. pneumoniae TIGR4.
- Middle ear bullae were examined via culture and microscopy at various time points post-infection.
- Scanning electron microscopy and immunofluorescent staining were employed to visualize bacterial communities and matrix components.
Main Results:
- Biofilm-like dense material was observed in the middle ear up to 12 days post-infection.
- Scanning electron microscopy confirmed bacteria within an electron-dense matrix, consistent with in vitro biofilms.
- Immunofluorescent staining identified pneumococcal communities within the middle ear material.
Conclusions:
- Pneumococci form biofilms in vivo, a process potentially linked to neutrophil extracellular trap formation.
- These findings suggest a role for in vivo biofilms in antibiotic treatment failure and persistent pneumococcal otitis media.
More Related Videos
08:25Visualization of Streptococcus pneumoniae within Cardiac Microlesions and Subsequent Cardiac Remodeling
Published on: April 7, 2015
11:32Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
Published on: February 23, 2014
Related Concept Videos
01:14Atypical Pneumonia
01:29Pneumonia I: Introduction
01:30Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
01:29Microbiota of the Respiratory Tract