Related Experiment Video

Updated: Aug 17, 2026

Experimental Human Pneumococcal Carriage
07:47

Experimental Human Pneumococcal Carriage

Published on: February 15, 2013

Dynamics of pneumococcal carriage among healthy Icelandic children attending day-care centres

Gunnar Tomasson1, Thorolfur Gudnason, Karl G Kristinsson

  • 1Department of Clinical Microbiology, Landspitali University Hospital, Reykjavik, Iceland.

Scandinavian Journal of Infectious Diseases
|July 14, 2005
PubMed

Insights

Antimicrobial resistance in pneumococci is a public health concern. Serotype prevalence varied significantly, with most resistant strains not covered by the current vaccine.

Area of Science:

  • Microbiology
  • Epidemiology
  • Public Health

Background:

  • Invasive pneumococcal disease and antimicrobial resistance pose significant public health challenges.
  • Understanding pneumococcal serotype prevalence and temporal changes is crucial for vaccine development and public health strategies.

Purpose of the Study:

  • To investigate pneumococcal serotype prevalence, antimicrobial resistance, and clonality in children attending day-care centers in Reykjavik.
  • To assess the impact of antimicrobial use on the carriage of penicillin non-susceptible pneumococcal isolates.

Main Methods:

  • Collection of nasopharyngeal swabs from children at five day-care centers in Reykjavik (1992-1999).
  • Culture and selective isolation of pneumococci.
  • Serotyping and pulsed field gel electrophoresis (PFGE) for clonality analysis.
  • Questionnaires to parents regarding antimicrobial (AM) use.

Main Results:

  • Of 1228 swabs, 640 yielded pneumococci; 13.9% showed decreased penicillin susceptibility.
  • Children with recent AM use or attending centers with high AM use were more likely to carry penicillin non-susceptible isolates.
  • Serotypes 6A, 6B, and 23F were most common (48%). Penicillin non-susceptible isolates were predominantly serotype 6B or 19A.
  • Significant year-to-year fluctuations in serotype prevalence were observed.
  • Only 51% of isolates belonged to serotypes covered by the 7-valent conjugated vaccine.

Conclusions:

  • Significant variation in pneumococcal serotype prevalence occurred annually.
  • Penicillin non-susceptible pneumococci were associated with antimicrobial use.
  • The 7-valent pneumococcal conjugate vaccine may not cover a substantial proportion of circulating serotypes, particularly those with reduced penicillin susceptibility.

More Related Videos

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria11:32

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness12:21

A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness

Published on: September 28, 2022

Related Concept Videos

Development of the Oral Microbiota01:28

Development of the Oral Microbiota

The establishment of the oral microbiome begins before birth, challenging the long-held belief that the fetal oral cavity is sterile. The presence of oral microbes such as Streptococcus and Fusobacterium in amniotic fluid suggests that microbial exposure may occur in utero, potentially through translocation from the maternal oral or gastrointestinal tract. This early colonization primes the neonatal immune system and sets the stage for subsequent microbial succession. Maternal health,...
Microbiota of the Respiratory Tract01:29

Microbiota of the Respiratory Tract

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Pneumonia I: Introduction01:30

Pneumonia I: Introduction

Pneumonia is an acute respiratory infection that targets the lungs, specifically the alveoli. These tiny air sacs, essential for oxygen exchange, become engorged with pus and fluid, severely hindering breathing, decreasing oxygen absorption, and causing significant pain and discomfort during respiration.
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...
Pneumonia I: Introduction01:29

Pneumonia I: Introduction

Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...