Poster Presentation Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

Pneumococcal antibiotic resistance trends over time in invasive pneumococcal diseases in rural Gambia   (#102)

Molfa MM Minteh 1 , Rasheed Salaudeen RS Salaudeen 1 , Ousman OB Barjo 1 , Baleng Mahama WB Wutor 1 , Isaac IO Osei 1 2 , Grant GM Mackenzie 1 2 3 4
  1. Disease Control and Elimination, Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, Gambia
  2. Disease Control and Elimination, London School of Hygiene and Tropical Medicine, London, United Kingdom
  3. Murdoch Children's Research Institute, Melbourne, Australia
  4. Department of Paediatrics,, University of Melbourne,, Melbourne, Australia

Background 

Antimicrobial resistance (AMR) poses challenges for treating pneumococcal diseases. This study assessed AMR trends in Streptococcus pneumoniae in invasive pneumococcal diseases (IPD).

Method

We evaluated invasive S. pneumoniae , isolated in rural Gambia over a 15-year period between 2008-2022. Standardised, population-based Surveillance for invasive bacterial causes of pneumonia, sepsis, and meningitis was conducted in Basse Health & Demographic Surveillance System from 2008-2017 and 2019-2022, while in Fuladu West Health & Demographic Surveillance System surveillance covered 2011-2014 and 2019-2022. S pneumoniae was identified by morphology and optochin sensitivity and ATCC 6583 was used as a reference strain. Antibiotic sensitivity was assessed using Kirby-Bauer disk diffusion method, apply CLSI standards to categorise isolates as resistant, intermediate, or sensitive to antibiotics. We used descriptive statistics to characterize the percentage and the trends of AMR in four time periods, 2008-2010, 2011-2013, 2014-2017, and 2019-2022. 

Results

Of 450 invasive isolates isolated in the four time periods, 34% (153/450) of patients were aged <1 year, and 75% were from blood culture.  Almost all isolates (94%) were resistant to cotrimoxazole. Proportions resistant to tetracycline were 56%, oxacillin 26%, chloramphenicol 20%, and ciprofloxacin 9%. There was limited variation in resistance to individual antibiotics over time. There was a decrease in tetracycline resistance over time (60% to 44%) and resistance to ≥3 drugs (33% to 16%).

 

Conclusions

There are modest levels of AMR in invasive S. pneumoniae isolates in rural Gambia. Resistance over time was relatively stable with some reductions in the proportion of tetracycline and multi-drug resistance.