Differences in nasopharyngeal bacterial carriage in preschool children from different socio-economic origins

Abstract

A prospective cohort study of preschool healthy children (3-6 years old) from two distinct socio-economic settings in the Brussels area, Belgium, was conducted during the years 2006-2008. The objectives were to evaluate nasopharyngeal colonization by Streptococcus pneumoniae, Staphylococcus aureus, Moraxella catarrhalis and Haemophilus influenzae at the time of PCV7 vaccine introduction and to assess the socio-economic level impact on flora composition and antibiotic resistance. Three hundred and thirty-three children were included and a total of 830 nasopharyngeal samples were collected together with epidemiological data. Pneumococcal serotypes and antibiotic resistance profiles were determined. Risk factors for carriage and bacterial associations were analysed by multivariate logistic regression. Carriage rates were high for all pathogens. Fifty per cent of the children were colonized at least once with S. aureus, 69% with S. pneumoniae, 67% with M. catarrhalis and 83% with H. influenzae. PCV7 uptake was higher among children from a higher socio-economic setting and S. pneumoniae serotypes varied accordingly. Children from lower socio-economic schools were more likely to carry M. catarrhalis, S. aureus and antibiotic-resistant S. pneumoniae, including a high proportion of non-typeable pneumococcal strains. Positive associations between S. pneumoniae and H. Influenza, between H. influenzae and M. catarrhalis and between H. influenzae and S. aureus were detected. Our study indicates that nasopharynx flora composition is influenced not only by age but also by socio-economic settings. A child's nasopharynx might represent a unique dynamic environment modulated by intricate interactions between bacterial species, host immune system and PCV7 immunization.

Pneumococcal Infection in Children: Everyday Practice

“…Поскольку спектр серотипов может варьировать на разных территориях страны [31, 33,34], информация об актуальном серотиповом распределении пневмокок-ка и его изменениях во времени является одним из глав-ных факторов для успешного внедрения пневмококковой вакцинации в любой стране. На современном этапе дан-ных о серотипах пневмококка в Российской Федерации мало, поскольку большинство исследований было выпол-нено 20-30 лет назад [35,36].…”

The Gene Polymorphism of IL-17 G-152A is Associated with Increased Colonization of Streptococcus pneumoniae in Young Finnish Children

“…Up to 50% of children acquire S. pneumoniae in their nasopharynx at least once during the first 12 months of life. 1,2 The prevalence of S. pneumoniae increases in children during the first 24 months and then starts to decrease at 3-5 years of age. 3 It has been shown in previous studies that children who have been colonized by S. pneumoniae at early age (1-6 months) are in increased risk for developing respiratory infections and recurrent wheezing in early life and asthma in later childhood.…”

The Moraxella catarrhalis Nitric Oxide Reductase Is Essential for Nitric Oxide Detoxification

“…It is estimated that 2 to 4 million exacerbations of COPD in the United States are attributable to M. catarrhalis infection each year (46). M. catarrhalis has been implicated in other infections, including community-acquired pneumonia (64), and extremely rarely may cause fatal bacteremia or pneumonia in patients with preexisting health conditions, such as immunodeficiency or impaired airway defenses (57).Studies show that nasopharyngeal colonization with M. catarrhalis is common in infants and young children, and a high rate of colonization is associated with an increased risk of otitis media (16,31). Recent surveys of nasopharyngeal colonization of Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and M. catarrhalis showed that colonization with M. catarrhalis is highest among these pathogens surveyed in children between 2 and 12 years of age (42).…”

“…Recent surveys of nasopharyngeal colonization of Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and M. catarrhalis showed that colonization with M. catarrhalis is highest among these pathogens surveyed in children between 2 and 12 years of age (42). M. catarrhalis frequently cocolonizes human nasopharyngeal mucosal surfaces with other bacteria, including Streptococcus pneumoniae (31,42), Staphylococcus aureus (31), and H. influenzae (31,68). Efforts to identify M. catarrhalis adhesins have uncovered several bacterial surface proteins that facilitate M. catarrhalis attachment to human epithelial cells in vitro (20,27,28,36,40,41,52,54).…”

“…Studies show that nasopharyngeal colonization with M. catarrhalis is common in infants and young children, and a high rate of colonization is associated with an increased risk of otitis media (16,31). Recent surveys of nasopharyngeal colonization of Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and M. catarrhalis showed that colonization with M. catarrhalis is highest among these pathogens surveyed in children between 2 and 12 years of age (42).…”