A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load.
Bacterial efflux pumps transport small molecules from the cytoplasm or periplasm outside the cell. Efflux pump activity is typically increased in multi-drug resistant (MDR) pathogens; chemicals that inhibit efflux pumps may have potential for antibiotic development. Using an in-cell screen, we ident...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2018-06-01
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| Series: | PLoS Pathogens |
| Online Access: | https://doi.org/10.1371/journal.ppat.1007115 |
| _version_ | 1798020414937497600 |
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| author | Abigail L Reens Amy L Crooks Chih-Chia Su Toni A Nagy David L Reens Jessica D Podoll Madeline E Edwards Edward W Yu Corrella S Detweiler |
| author_facet | Abigail L Reens Amy L Crooks Chih-Chia Su Toni A Nagy David L Reens Jessica D Podoll Madeline E Edwards Edward W Yu Corrella S Detweiler |
| author_sort | Abigail L Reens |
| collection | DOAJ |
| description | Bacterial efflux pumps transport small molecules from the cytoplasm or periplasm outside the cell. Efflux pump activity is typically increased in multi-drug resistant (MDR) pathogens; chemicals that inhibit efflux pumps may have potential for antibiotic development. Using an in-cell screen, we identified three efflux pump modulators (EPMs) from a drug diversity library. The screening platform uses macrophages infected with the human Gram-negative pathogen Salmonella enterica (Salmonella) to identify small molecules that prevent bacterial replication or survival within the host environment. A secondary screen for hit compounds that increase the accumulation of an efflux pump substrate, Hoechst 33342, identified three small molecules with activity comparable to the known efflux pump inhibitor PAβN (Phe-Arg β-naphthylamide). The three putative EPMs demonstrated significant antibacterial activity against Salmonella within primary and cell culture macrophages and within a human epithelial cell line. Unlike traditional antibiotics, the three compounds did not inhibit bacterial growth in standard microbiological media. The three compounds prevented energy-dependent efflux pump activity in Salmonella and bound the AcrB subunit of the AcrAB-TolC efflux system with KDs in the micromolar range. Moreover, the EPMs display antibacterial synergy with antimicrobial peptides, a class of host innate immune defense molecules present in body fluids and cells. The EPMs also had synergistic activity with antibiotics exported by AcrAB-TolC in broth and in macrophages and inhibited efflux pump activity in MDR Gram-negative ESKAPE clinical isolates. Thus, an in-cell screening approach identified EPMs that synergize with innate immunity to kill bacteria and have potential for development as adjuvants to antibiotics. |
| first_indexed | 2024-04-11T16:57:07Z |
| format | Article |
| id | doaj.art-cc8650ba36e94f3ea9173a0d6f6850bd |
| institution | Directory Open Access Journal |
| issn | 1553-7366 1553-7374 |
| language | English |
| last_indexed | 2024-04-11T16:57:07Z |
| publishDate | 2018-06-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Pathogens |
| spelling | doaj.art-cc8650ba36e94f3ea9173a0d6f6850bd2022-12-22T04:13:14ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742018-06-01146e100711510.1371/journal.ppat.1007115A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load.Abigail L ReensAmy L CrooksChih-Chia SuToni A NagyDavid L ReensJessica D PodollMadeline E EdwardsEdward W YuCorrella S DetweilerBacterial efflux pumps transport small molecules from the cytoplasm or periplasm outside the cell. Efflux pump activity is typically increased in multi-drug resistant (MDR) pathogens; chemicals that inhibit efflux pumps may have potential for antibiotic development. Using an in-cell screen, we identified three efflux pump modulators (EPMs) from a drug diversity library. The screening platform uses macrophages infected with the human Gram-negative pathogen Salmonella enterica (Salmonella) to identify small molecules that prevent bacterial replication or survival within the host environment. A secondary screen for hit compounds that increase the accumulation of an efflux pump substrate, Hoechst 33342, identified three small molecules with activity comparable to the known efflux pump inhibitor PAβN (Phe-Arg β-naphthylamide). The three putative EPMs demonstrated significant antibacterial activity against Salmonella within primary and cell culture macrophages and within a human epithelial cell line. Unlike traditional antibiotics, the three compounds did not inhibit bacterial growth in standard microbiological media. The three compounds prevented energy-dependent efflux pump activity in Salmonella and bound the AcrB subunit of the AcrAB-TolC efflux system with KDs in the micromolar range. Moreover, the EPMs display antibacterial synergy with antimicrobial peptides, a class of host innate immune defense molecules present in body fluids and cells. The EPMs also had synergistic activity with antibiotics exported by AcrAB-TolC in broth and in macrophages and inhibited efflux pump activity in MDR Gram-negative ESKAPE clinical isolates. Thus, an in-cell screening approach identified EPMs that synergize with innate immunity to kill bacteria and have potential for development as adjuvants to antibiotics.https://doi.org/10.1371/journal.ppat.1007115 |
| spellingShingle | Abigail L Reens Amy L Crooks Chih-Chia Su Toni A Nagy David L Reens Jessica D Podoll Madeline E Edwards Edward W Yu Corrella S Detweiler A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. PLoS Pathogens |
| title | A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. |
| title_full | A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. |
| title_fullStr | A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. |
| title_full_unstemmed | A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. |
| title_short | A cell-based infection assay identifies efflux pump modulators that reduce bacterial intracellular load. |
| title_sort | cell based infection assay identifies efflux pump modulators that reduce bacterial intracellular load |
| url | https://doi.org/10.1371/journal.ppat.1007115 |
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