Antibiotic Susceptibility of Burkholderia pseudomallei Towards Co-trimoxazole and its Mechanism
| dc.contributor.author | Liana Lantong Anak Sumbu | |
| dc.date.accessioned | 2026-05-05T09:01:39Z | |
| dc.date.issued | 2026-04 | |
| dc.description | The etiologic agent, Burkholderia pseudomallei that causes the potentially fatal melioidosis, is known to be inherently resistant to a wide range of antimicrobial drugs. Co-trimoxazole, a combination of sulfamethoxazole and trimethoprim, is an important drug used in the eradication phase therapy of melioidosis. In recent years, there have been increasing reports of higher minimal inhibitory concentration (MIC) readings of co-trimoxazole for B. pseudomallei clinical isolates in Sarawak, Malaysian Borneo. Thus, this study is aimed to determine the prevalence and understand the mechanism of such phenomena in Sarawak. Antibiotic susceptibility was assessed using disk diffusion and E-test methods on B. pseudomallei clinical isolates collected from various hospitals in Sarawak. In addition, the characterisation of the isolates’ susceptibility against the co-trimoxazole components, trimethoprim and sulfamethoxazole, was performed using the broth microdilution method. All analyses of the MIC breakpoints were done according to the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antibiotic Susceptibility Testing (EUCAST) guidelines. Overall, the Sarawak clinical B. pseudomallei isolates exhibited susceptibility of 96.3% (CLSI) and 97.6% (EUCAST) towards co-trimoxazole invitro. Broth microdilution demonstrated that the isolates were resistant when treated with the separate components of co-trimoxazole, sulfamethoxazole or trimethoprim alone. However, they were generally susceptible when treated with the combination of sulfamethoxazole and trimethoprim (co-trimoxazole). Thus, clinicians should be confident that the co-trimoxazole is effective for the treatment of melioidosis. Analysis of the MIC results showed that the CLSI guideline is a valid guide for antibiotic susceptibility testing and antimicrobial resistance surveillance works in Sarawak. Although the co-trimoxazole resistance determinant, the bpeEF-oprC genes, were not well characterised, this study has provided iv some basis for future research pursuits. Furthermore, this study has established guidelines for the laboratory diagnosis, particularly for the betterment of antibiotic susceptibility testing and antimicrobial resistance surveillance of melioidosis cases in Sarawak. | |
| dc.identifier.uri | https://scholarhub.unimas.my/handle/123456789/644 | |
| dc.language.iso | English | |
| dc.publisher | Universiti Malaysia Sarawak | |
| dc.relation.ispartofseries | Faculty of Medicine and Health Sciences | |
| dc.title | Antibiotic Susceptibility of Burkholderia pseudomallei Towards Co-trimoxazole and its Mechanism | |
| dc.type | Masters |