High genetic diversity of Staphylococcus aureus clones among Gambian villagers

21 March 2016
With the global efforts of reducing pneumococcal disease through widespread introduction of pneumococcal vaccines. Concerns have emerged on the potential increase of morbidity and mortality from S. aureus disease in rural Africa, and West Africa in particular where very high rates of carriage of S. pneumoniae have been reported.

The study titled “High genetic diversity of Staphylococcus aureus strains colonising the nasopharynx of Gambian villagers before widespread use of pneumococcal conjugate vaccines” funded by Medical Research Council, was recently published in BioMed Central. The aim of the study was to evaluate the prevalence of antibiotic susceptibility patterns and genotypes of S. aureus isolated from the nasopharynx of healthy individuals in rural Gambia before the introduction of the routine use of pneumococcal conjugate vaccines in the country.

The study which was conducted by MRC Unit The Gambia in the villages of West Coast Region shows that nasopharyngeal carriage of S. aureus in rural Gambia is high in all age groups, with approximately 1 out of 4 individuals being carriers in the pre-pneumococcal vaccination era. There are indications that nasopharyngeal carriage of S. aureus could be inversely related to carriage of S. pneumoniae amongst younger children in The Gambian and that S. aureus clones show significant genetic diversity suggesting worldwide dissemination.

These findings could provide a useful background for impact studies evaluating the introduction of pneumococcal vaccines or other interventions targeted at the control of S. aureus infection and disease.

(left) Chinelo Ebruke, Phd student, Vaccines and Immunity Team (Right)  Martin Antonio Head, Molecular Microbiology and Mycobacteriology

Chinelo Ebruke, PhD student, Vaccines and Immunity Theme and Martin Antonio, Head, Molecular Microbiology and Mycobacteriology

According to the first author of this publication Chinelo Ebruke, PhD student from the Vaccines and Immunity Theme,  “Staphylococcus aureus is one of the leading causes of invasive bacterial infections among young children. With increasing efforts to controlling pneumococcal disease, the relative importance of S. aureus in causing disease in children is likely to gain greater significance. This study describes nasopharyngeal carriage of S. aureus and for the first time circulating clones of S. aureus in The Gambia pre-pneumococcal vaccination, providing baseline data for monitoring subsequent changes in disease patterns in The Gambia following the introduction of pneumococcal vaccines.”

Acknowledgement: The West Coast Region community, Vaccines and Immunity Theme, Ministry of Health and Social Welfare, and all partners.

Authors: Chinelo Ebruke, Michel Dione, Brigitte Walter, Archibald Worwui, Richard Adegbola, Anna Roca, Martin Antonio.

Read more about the study on the BioMed Central website on http://www.biomedcentral.com/1471-2180/16/38