Idris, Nurulain and Leong, Kok Hoong and Wong, Eng Hwa and Rahim, Nusaibah Abdul (2023) Unveiling synergism of polymyxin B with chloramphenicol derivatives against multidrug-resistant (MDR) Klebsiella pneumoniae. Journal of Antibiotics, 76 (12). pp. 711-719. ISSN 0021-8820, DOI https://doi.org/10.1038/s41429-023-00659-2.
Full text not available from this repository.Abstract
Polymyxins are last-line antibiotics against multidrug-resistant Klebsiella pneumoniae but using polymyxins alone may not be effective due to emerging resistance. A previous study found that combining polymyxin B with chloramphenicol effectively kills MDR K. pneumoniae, although the bone marrow toxicity of chloramphenicol is concerning. The aim of this study is to assess the antibacterial efficacy and cytotoxicity of polymyxin B when combined with chloramphenicol and its derivatives, namely thiamphenicol and florfenicol (reported to have lesser toxicity compared to chloramphenicol). The antibacterial activity was evaluated with antimicrobial susceptibility testing using broth microdilution and time-kill assays, while the cytotoxic effect on normal bone marrow cell line, HS-5 was evaluated using the MTT assay. All bacterial isolates tested were found to be susceptible to polymyxin B, but resistant to chloramphenicol, thiamphenicol, and florfenicol when used alone. The use of polymyxin B alone showed bacterial regrowth for all isolates at 24 h. The combination of polymyxin B and florfenicol demonstrated additive and synergistic effects against all isolates (>= 2 log(10) cfu ml(-1) reduction) at 4 and 24 h, respectively, while the combination of polymyxin B and thiamphenicol resulted in synergistic killing at 24 h against ATCC BAA-2146. Furthermore, the combination of polymyxin B with florfenicol had the lowest cytotoxic effect on the HS-5 cells compared to polymyxin B combination with chloramphenicol and thiamphenicol. Overall, the combination of polymyxin B with florfenicol enhanced bacterial killing against MDR K. pneumoniae and exerted minimal cytotoxic effect on HS-5 cell line.
| Item Type: | Article |
|---|---|
| Funders: | This research was supported by the Faculty Research Grant (Geran Penyelidikan Fakulti), Faculty of Pharmacy, Universiti Malaya (GPF001B-2020). |
| Subjects: | R Medicine > RM Therapeutics. Pharmacology R Medicine > RS Pharmacy and materia medica |
| Divisions: | Faculty of Pharmacy > Department of Clinical Pharmacy and Pharmacy Practice Faculty of Pharmacy > Department of Pharmaceutical Life Sciences |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 08 Sep 2025 04:58 |
| Last Modified: | 08 Sep 2025 04:58 |
| URI: | http://eprints.um.edu.my/id/eprint/50613 |
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