Project description:The emergence of polymyxin resistance in carbapenem-resistant and extended-spectrum -lactamase (ESBL)-producing bacteria is a critical threat to human health, and new treatment strategies are urgently required. Here, we investigated the ability of the safe-for-human use ionophore PBT2 to restore antibiotic sensitivity in polymyxin-resistant, ESBL-producing, carbapenem-resistant Gram-negative human pathogens. PBT2 was observed to resensitize Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii and Pseudomonas aeruginosa to last-resort polymyxin class antibiotics, including the less-toxic next-generation polymyxin derivative, FADDI-287. We were unable to select for mutants resistant to PBT2 + FADDI-287 in polymyxin resistant E. coli containing a plasmid-borne mcr-1 gene or K. pneumoniae carrying a chromosomal mgrB mutation. Using a highly invasive K. pneumoniae strain engineered for polymyxin resistance through mgrB mutation, we successfully demonstrated the efficacy of PBT2 + FADDI-287 in vivo for the treatment of Gram-negative sepsis. These data present a new treatment modality to break antibiotic resistance in high priority polymyxin-resistant Gram-negative pathogens.
Project description:Polymyxin B is considered as a last-resort antibiotic for multidrug-resistant or extensively drug-resistant gram-negative bacterial infections. Addressing Salmonella resistance to polymyxin B is crucial for global public health. In this study, transcriptomic detection and analysis were used to clarify the mechanisms by which CpxA-deleted S.typhimurium is involved in resistance to polymyxin B stress, which may be related to processes such as increased assembly of bacterial flagella.
Project description:Polymyxins are increasingly used as the critical last-resort therapeutic options for multidrug-resistant gram-negative bacteria. Unfortunately, polymyxin resistance has increased gradually for the last few years. Although studies on mechanisms of polymyxin are expanding, system-wide analyses of the underlying mechanism for polymyxin resistance and stress response are still lacking. To understand how Klebsiella pneumoniae adapt to colistin (polymyxin E) pressure, we carried out proteomic analysis of Klebsiella pneumoniae strain cultured with different concentrations of colistin. Our results showed that the proteomic responses to colistin treatment in Klebsiella pneumoniae involving several pathways, including (i) gluconeogenesis and TCA cycle; (ii) arginine biosynthesis; (iii) porphyrin and chlorophyll metabolism; and (iv) enterobactin biosynthesis. Interestingly, decreased abundance of class A β-lactamases including TEM, SHV-11, SHV-4 were observed in cells treated with colistin. Moreover, we also present comprehensive proteome atlases of paired polymyxin-susceptible and -resistant Klebsiella pneumoniae strains. The polymyxin-resistant strain Ci, a mutant of Klebsiella pneumoniae ATCC BAA 2146, showed missense mutation in crrB. The crrB mutant Ci, which displayed lipid A modification with 4-amino-4-deoxy-L-arabinose (L-Ara4N) and palmitoylation, showed striking increases of CrrAB, PmrAB, PhoPQ, ArnBCADT and PagP. We hypothesize that crrB mutations induce elevated expression of the arnBCADTEF operon and pagP via PmrAB and PhoPQ. Moreover, multidrug efflux pump KexD, which was induced by crrB mutation, also contributed to colistin resistance. Overall, our results demonstrated proteomic responses to colistin treatment and the mechanism of CrrB-mediate colistin resistance, which may further offer valuable information to manage polymyxin resistance.
2022-04-11 | PXD018528 | Pride
Project description:mechanisms of polymyxin-resistant
| PRJNA847003 | ENA
Project description:haracteristics of polymyxin-resistant