| Structural highlights
Function
MCR1_ECOLX Probably catalyzes the addition of a phosphoethanolamine moiety to lipid A. Phosphoethanolamine modification of lipid A gives polymyxin resistance (PubMed:26603172).[1] Confers resistance to polymyxin-type antibiotics; expression of the Mcr-1 protein in E.coli increases colistin and polymyxin B minimal inhibitory concentration (MIC) from 0.5 mg/ml to 2.0 mg/ml. The pHNSHP45 plasmid can transfer efficiently (0.1 to 0.001) to other E.coli strains by conjugation and increases polymxin MIC by 8- to 16-fold; it may not require selective pressure to be maintained in the cell. When transformed into K.pneumoniae or P.aeruginosa it also increases polymxin MIC 8- to 16-fold. In a murine (BALB/c mice) thigh infection study using an mcr1-encoding plasmid isolated from a human patient, the plasmid confers in vivo protection against colistin (PubMed:26603172).[2]
Publication Abstract from PubMed
The emergence and rapid spread of the mobile colistin resistance gene mcr-1 among bacterial species and hosts significantly challenge the efficacy of "last-line" antibiotic colistin. Previously, we reported silver nitrate and auranofin serve as colistin adjuvants for combating mcr-1-positive bacteria. Herein, we uncovered more gold-based drugs and nanoparticles, and found that they exhibited varying degree of synergisms with colistin on killing mcr-1-positive bacteria. However, pre-activation of the drugs by either glutathione or N-acetyl cysteine, thus releasing and accumulating gold ions, is perquisite for their abilities to substitute zinc cofactor from MCR-1 enzyme. X-ray crystallography and biophysical studies further supported the proposed mechanism. This study not only provides basis for combining gold-based drugs and colistin for combating mcr-1-positive bacterial infections, but also undoubtedly opens a new horizon for metabolism details of gold-based drugs in overcoming antimicrobial resistance.
Gold drugs as colistin adjuvants in the fight against MCR-1 producing bacteria.,Zhang Q, Wang M, Hu X, Yan A, Ho PL, Li H, Sun H J Biol Inorg Chem. 2023 Jan 20. doi: 10.1007/s00775-022-01983-y. PMID:36662362[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Liu YY, Wang Y, Walsh TR, Yi LX, Zhang R, Spencer J, Doi Y, Tian G, Dong B, Huang X, Yu LF, Gu D, Ren H, Chen X, Lv L, He D, Zhou H, Liang Z, Liu JH, Shen J. Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study. Lancet Infect Dis. 2016 Feb;16(2):161-8. doi: 10.1016/S1473-3099(15)00424-7. Epub, 2015 Nov 19. PMID:26603172 doi:http://dx.doi.org/10.1016/S1473-3099(15)00424-7
- ↑ Liu YY, Wang Y, Walsh TR, Yi LX, Zhang R, Spencer J, Doi Y, Tian G, Dong B, Huang X, Yu LF, Gu D, Ren H, Chen X, Lv L, He D, Zhou H, Liang Z, Liu JH, Shen J. Emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and human beings in China: a microbiological and molecular biological study. Lancet Infect Dis. 2016 Feb;16(2):161-8. doi: 10.1016/S1473-3099(15)00424-7. Epub, 2015 Nov 19. PMID:26603172 doi:http://dx.doi.org/10.1016/S1473-3099(15)00424-7
- ↑ Zhang Q, Wang M, Hu X, Yan A, Ho PL, Li H, Sun H. Gold drugs as colistin adjuvants in the fight against MCR-1 producing bacteria. J Biol Inorg Chem. 2023 Jan 20. doi: 10.1007/s00775-022-01983-y. PMID:36662362 doi:http://dx.doi.org/10.1007/s00775-022-01983-y
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