Nasopharyngeal bacteria found on blood agar plates from healthy children in Greenland
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Updated: Oct 21, 2026
Experimental Human Pneumococcal Carriage
Published on: February 15, 2013
1Dept. of Otolaryngology, Head & Neck Surgery, Rigshospitalet, University of Copenhagen, Denmark. rh03259@rh.dk
Insights
Healthy Greenlandic children carry common aerobic bacteria, but pathogenic bacteria like Staphylococcus aureus and Streptococcus pneumoniae are frequent, especially in younger children. This high carriage rate may explain frequent upper respiratory tract infections and otitis media.
Area of Science:
- Microbiology
- Pediatrics
- Epidemiology
Background:
- Nasopharyngeal bacterial carriage is crucial for understanding childhood respiratory infections.
- Greenlandic children experience high rates of upper respiratory tract infections (URTI) and otitis media (OM).
- Baseline data on bacterial flora in Greenlandic children is limited.
Purpose of the Study:
- To characterize aerobic nasopharyngeal bacterial carriage in healthy Greenlandic children.
- To establish a baseline for future microbiological and immunological research.
- To inform antibiotic treatment strategies for URTI and OM in Greenland.
Main Methods:
- Systematic aerobic culture of nasopharyngeal swabs from 70 healthy children (aged 0-8 years) in Greenland.
- Use of 5% horse blood agar and chocolate agar for bacterial isolation.
- Identification of bacteria using conventional microbiological methods.
Main Results:
- Potentially pathogenic bacteria were found in 94% of healthy children.
- High frequencies of Staphylococcus aureus, Streptococcus pneumoniae, and Moraxella catarrhuis were observed, particularly in younger children.
- Haemophilus influenzae non-b was prevalent (67-76%), while H. influenzae type b was carried by 11.4%.
Conclusions:
- Healthy Greenlandic children exhibit a high carrier frequency of potentially pathogenic nasopharyngeal bacteria.
- The prevalence of specific pathogens like S. aureus, S. pneumoniae, and M. catarrhuis varies by age.
- High bacterial carriage may contribute to the elevated incidence of URTI and OM in this population.
Abstract:
We have systematically studied the aerobic nasopharyngeal bacteria isolated from swabs by unselective subculturing on 5% horse blood agar and chocolate agar in 70 healthy children aged 0-1, 3-5 and 8 years in Nuuk and Sisimiut, Greenland. The purpose was to provide a basis for a better understanding of the infectious pathology and blind antibiotic treatment against potential pathogens thereby improving standard antimicrobial treatment of upper respiratory tract infections (URTI) and otitis media (OM) among children in Greenland. The study serves also as a baseline for future microbiological and immunological research projects. The children were clinically examined for any infectious diseases and a medical history was obtained which allowed for selection of children without a history of severe clinical infection. Nasopharyngeal swabs obtained via the oral route were instantly spread on 5% blood agar and chocolate agar culture plates and incubated aerobically. Subsequently, potentially pathogenic as well as non-pathogenic bacteria were identified by conventional methods. Healthy children in Greenland carry grossly the same aerobic bacterial flora as children in other parts of the world but potentially pathogenic bacteria were found in very high frequency (94%). Staphylococcus aureus, Streptococcus pneumoniae and Moraxella catarrhalis were found in higher frequencies in the youngest children. Haemophilus influenzae non-b was found in high frequencies in all age groups (67-76%). H. influenzae type b was carried by 11.4%. Group A streptococci were found more frequently in older children and in children from Sisimiut. Of M. catarrhalis strains 88% produced beta-lactamase. Neisseria meningitidis, Mycoplasma pneumoniae and chlamydiae were not detected at all. The high carrier frequency of potentially pathogenic bacteria in healthy children in Greenland may be related to the high frequency of URTI's and episodes of OM among children in Greenland.
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