Related Experiment Video
Updated: May 9, 2026
Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
Published on: September 11, 2020
Mixed pneumococcal-nontypeable Haemophilus influenzae otitis media is a distinct clinical entity with unique
Ron Dagan1, Eugene Leibovitz, David Greenberg
1Pediatric Infectious Diseases Unit, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. rdagan@bgu.ac.il
Background:
Complex (ie, recurrent, nonresponsive, or chronic) otitis media (OM) is frequent and is often caused by a mixed-pathogen infection with biofilm formation. We conducted this study to characterize children with OM due to mixed Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi) infections (M-OM) and those with OM due to single, S. pneumoniae-only infections (S-OM) and to examine whether pneumococcal serotypes associated with M-OM differed from those associated with S-OM.
Methods:
In a 10-year prospective study in southern Israel, the clinical and demographic variables and pneumococcal serotypes associated with M-OM were compared to those associated with S-OM in children <3 years old.
Results:
M-OM episodes were significantly more likely to be found in Bedouin children (for whom living conditions are crowded and colonization occurs during early life) and in older children with bilateral OM, recurrent OM, previous tympanocentesis, and lower body temperature, as well as during the winter, suggesting an association with recurrence/chronicity. M-OM was associated with pneumococcal serotypes most commonly carried by healthy children, whereas S-OM was associated with serotypes previously shown to have a higher disease potential.
Conclusions:
S-OM and M-OM differ clinically and epidemiologically, with overlapping characteristics. Our findings are in agreement with clinical and experimental reports associating respiratory tract biofilms and mixed infections with pneumococcal serotypes of lower virulence and higher capacity to colonize the nasopharynx in healthy individuals.
Insights
Complex otitis media (OM) in children often involves mixed pathogens. This study found that mixed infections (M-OM) are linked to common pneumococcal serotypes, unlike single infections (S-OM), suggesting differences in virulence and colonization.
Area of Science:
- Pediatric Infectious Diseases
- Microbiology
- Epidemiology
Background:
- Complex otitis media (OM) frequently involves mixed pathogens and biofilm formation.
- Distinguishing between mixed S. pneumoniae and NTHi (M-OM) and single S. pneumoniae (S-OM) infections is crucial for understanding OM pathogenesis.
- Previous research indicates biofilm formation and mixed infections may involve less virulent bacterial strains.
Purpose of the Study:
- To characterize clinical and demographic differences between M-OM and S-OM in young children.
- To compare pneumococcal serotypes associated with M-OM versus S-OM.
- To investigate the relationship between specific pneumococcal serotypes and OM infection types.
Main Methods:
- A 10-year prospective study was conducted in southern Israel.
- Clinical and demographic data were collected for children under 3 years old.
- Pneumococcal serotypes were identified and compared between M-OM and S-OM groups.
Main Results:
- M-OM was more prevalent in Bedouin children, older children, those with recurrent or bilateral OM, and during winter.
- M-OM was associated with pneumococcal serotypes commonly found in healthy carriers.
- S-OM was linked to serotypes previously associated with higher disease potential.
Conclusions:
- Clinical and epidemiological profiles of S-OM and M-OM differ, though some characteristics overlap.
- Findings support the hypothesis that respiratory tract biofilms and mixed infections involve less virulent pneumococcal serotypes with higher colonization capacity.
- This suggests a potential role for serotype-specific virulence and colonization in the development of complex otitis media.
Related Concept Videos
01:14Atypical Pneumonia
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...
01:29Pneumonia I: Introduction
01:30Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed.
01:30Pneumonia III: Complications and Assessment
01:22Bacterial Meningitis I: Introduction