Implementing an antibiogram profile to aid rational antimicrobial therapy and improving infection prevention in an urban hospital in The Gambia; strategies and lessons for low income and middle-income countries.

Background: Diagnostic microbiological capabilities remain a challenge in low- and middle-income countries resulting in major gaps. The global antimicrobial resistance burden has necessitated use of appropriate prescribing to curb the menace. This study highlights the process used to develop an antibiogram to monitor resistance at a secondary-level health facility to aid empirical clinical decision making. Methods: This retrospective cross-sectional descriptive study used 3 years of cumulative data at the Medical Research Council Unit The Gambia from January 2016 to December 2018. Phenotypic data was manually imputed into WHONET and the cumulative antibiogram constructed using standardised methodologies according to CLSI M39-A4 guidelines. Pathogens were identified by standard microbiological methods and antimicrobial susceptibility testing was performed using Kirby-Bauer disc diffusion method according to CLSI M100 guidelines. Results: A total of 14776 non-duplicate samples (blood cultures n=4382, urines n=4914, other miscellaneous swabs and aspirates n=2821 and n=390 respectively, sputa n=334, stools n=1463, CSF 353 and other samples n= 119) were processed of which 1163 (7.9%) were positive for clinically significant pathogens. Among the 1163 pathogens, E. coli (n= 315) S. aureus (n=232), and K. pneumoniae (n=96) were the leading cause of disease Overall, the susceptibility for E. coli and K. pneumoniae from all samples were: trimethoprim-sulfamethoxazole (17% and 28%), tetracycline (26% and 33%), gentamicin (72% and 46%), chloramphenicol (76 and 60%), and ciprofloxacin (69% and 59%), amoxicillin/clavulanic (77% and 54%) respectively. Extended spectrum beta-lactamase resistance was present in 23% (71/315) vs 35% (34/96) respectively. S. aureus susceptibility for methicillin was 99%. Conclusion: This antibiogram has confirmed susceptibility to commonly used antimicrobials was higher for E. coli than K. pneumoniae with high ESBL resistance warranting surveillance. An alternative aminoglycoside with better sensitivity such as amikacin might be relevant although this was not tested and that cloxacillin remains a drug of choice for the Staphylococci.