Amidochelocardin Overcomes Resistance Mechanisms Exerted on Tetracyclines and Natural Chelocardin

Hennessen, Fabienne; Miethke, Marcus; Zaburannyi, Nestor; Loose, Maria; Lukežič, Tadeja; Bernecker, Steffen; Hüttel, Stephan; Jansen, Rolf; Schmiedel, Judith; Fritzenwanker, Moritz; Imirzalioglu, Can; Vogel, Jörg; Westermann, Alexander J.; Hesterkamp, Thomas; Stadler, Marc; Wagenlehner, Florian; Petković, Hrvoje; Herrmann, Jennifer; Müller, Rolf

doi:10.3390/antibiotics9090619

Cited by 11 publications

(21 citation statements)

References 78 publications

(116 reference statements)

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“…For this purpose, the CHD biosynthetic gene cluster in Amycolatopsis sulphurea 337 was combined with genes from the oxytetracycline biosynthesis pathway of Streptomyces rimosus , and production peak titres of the novel hybrid compound CDCHD up to 400 mg l −1 were achieved 191 . CDCHD represents a new broad-spectrum antibiotic active against pathogens of the ESKAPE panel (including a large number of clinical isolates) 106 , which can be routinely supplied at the multi-gram scale with >95% purity by using large-scale in-house fermentation at the Helmholtz Centre for Infection Research (HZI) (~100-l batch cultures) and optimized downstream processing. Due to the lack of cross-resistance to known antibiotics (for example, preserved activity against pathogens carrying multiple tetracycline (TET) resistance determinants), the good production yield and the fact that efficacy for CHD treatment was already shown in a small phase II study 338 , CDCHD was chosen to enter a lead optimization programme (see Acknowledgements).…”

Section: Synthetic Hit Compoundsmentioning

confidence: 99%

“…It is important that a range of relevant assays is used to thoroughly select and profile novel hit compounds. These assays should have a high physiological significance, which may be applicable to biomimetic assays 105 , for example, by using defined culture media such as artificial urine for activity screens with uropathogens 106 , 107 , iron-depleted media that simulate bacterial growth conditions during bloodstream or wound infections 108 , 109 or assaying host–bacteria interactions 110 . Such schemes can further include the screening for new MoA(s), new drug sensitizing modes, non-killing mechanisms (e.g.…”

Section: Synthetic Hit Compoundsmentioning

confidence: 99%

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Towards the sustainable discovery and development of new antibiotics

et al. 2021

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An ever-increasing demand for novel antimicrobials to treat life-threatening infections caused by the global spread of multidrug-resistant bacterial pathogens stands in stark contrast to the current level of investment in their development, particularly in the fields of natural-product-derived and synthetic small molecules. New agents displaying innovative chemistry and modes of action are desperately needed worldwide to tackle the public health menace posed by antimicrobial resistance. Here, our consortium presents a strategic blueprint to substantially improve our ability to discover and develop new antibiotics. We propose both short-term and long-term solutions to overcome the most urgent limitations in the various sectors of research and funding, aiming to bridge the gap between academic, industrial and political stakeholders, and to unite interdisciplinary expertise in order to efficiently fuel the translational pipeline for the benefit of future generations.

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Section: Synthetic Hit Compoundsmentioning

confidence: 99%

Section: Synthetic Hit Compoundsmentioning

confidence: 99%

Towards the sustainable discovery and development of new antibiotics

et al. 2021

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“…Considering unusual mode of action of CHD [ 26 ], which is still not clearly understood, and in an attempt to increase yield of CHD by overcoming possible self-resistance issues during heterologous expression of CHD, we constructed a second integrative cosmid carrying entire CHD BGC with an additional copy of CHD efflux pump gene chdR under control of the strong constitutive promoter P ermE* (construct pOJ436-PermE*-chdR-CHD12). However, the additional copy of efflux pump gene chdR did not lead to a significant increase of production yields of CHD in S. albus del14, reaching up to 60 mg/L (Fig.…”

Section: Resultsmentioning

confidence: 99%

Heterologous expression of the atypical tetracycline chelocardin reveals the full set of genes required for its biosynthesis

et al. 2020

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Background Chelocardin (CHD) exhibits a broad-spectrum antibiotic activity and showed promising results in a small phase II clinical study conducted on patients with urinary tract infections. Importantly, CHD was shown to be active also against tetracycline-resistant Gram-negative pathogens, which is gaining even more importance in today’s antibiotic crisis. We have demonstrated that modifications of CHD through genetic engineering of its producer, the actinomycete Amycolatopsis sulphurea, are not only possible but yielded even more potent antibiotics than CHD itself, like 2-carboxamido-2-deacetyl-chelocardin (CD-CHD), which is currently in preclinical evaluation. A. sulphurea is difficult to genetically manipulate and therefore manipulation of the chd biosynthetic gene cluster in a genetically amenable heterologous host would be of high importance for further drug-discovery efforts. Results We report heterologous expression of the CHD biosynthetic gene cluster in the model organism Streptomyces albus del14 strain. Unexpectedly, we found that the originally defined CHD gene cluster fails to provide all genes required for CHD formation, including an additional cyclase and two regulatory genes. Overexpression of the putative pathway-specific streptomyces antibiotic regulatory protein chdB in A. sulphurea resulted in an increase of both, CHD and CD-CHD production. Applying a metabolic-engineering approach, it was also possible to generate the potent CHD analogue, CD-CHD in S. albus. Finally, an additional yield increase was achieved in S. albus del14 by in-trans overexpression of the chdR exporter gene, which provides resistance to CHD and CDCHD. Conclusions We identified previously unknown genes in the CHD cluster, which were shown to be essential for chelocardin biosynthesis by expression of the full biosynthetic gene cluster in S. albus as heterologous host. When comparing to oxytetracycline biosynthesis, we observed that the CHD gene cluster contains additional enzymes not found in gene clusters encoding the biosynthesis of typical tetracyclines (such as oxytetracycline). This finding probably explains the different chemistries and modes of action, which make CHD/CD-CHD valuable lead structures for clinical candidates. Even though the CHD genes are derived from a rare actinomycete A. sulphurea, the yield of CHD in the heterologous host was very good. The corrected nucleotide sequence of the CHD gene cluster now contains all gene products required for the production of CHD in a genetically amenable heterologous host, thus opening new possibilities towards production of novel and potent tetracycline analogues with a new mode of action.

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“…CHD is a broad-spectrum antibiotic produced by the actinobacterium Amycolatopsis sulfurea and belongs to the class of the atypical tetracyclines ( 18 , 19 ). CDCHD is a modified derivative of CHD with an extended activity spectrum due to its ability to evade antibiotic efflux ( 20 , 21 ). Although atypical tetracyclines share the basic tetracycline scaffold, they do not primarily target the ribosomal 30S subunit as seen for typical tetracyclines ( 17 , 22 , 23 ).…”

Section: Introductionmentioning

confidence: 99%