Doxycycline induces Hok toxin killing in host E. coli.

The antibacterial efficacy of the tetracycline antibiotics has been greatly reduced by the development of resistance, hence a decline in their clinical use. The hok/sok locus is a type I toxin/antitoxin plasmid stability element, often associated with multi-drug resistance plasmids, especially ESBL-...

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Main Authors: Chinwe Uzoma Chukwudi, Liam Good
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2020-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0235633&type=printable
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author Chinwe Uzoma Chukwudi
Liam Good
author_facet Chinwe Uzoma Chukwudi
Liam Good
author_sort Chinwe Uzoma Chukwudi
collection DOAJ
description The antibacterial efficacy of the tetracycline antibiotics has been greatly reduced by the development of resistance, hence a decline in their clinical use. The hok/sok locus is a type I toxin/antitoxin plasmid stability element, often associated with multi-drug resistance plasmids, especially ESBL-encoding plasmids. It enhances host cell survivability and pathogenicity in stressful growth conditions, and increases bacterial tolerance to β-lactam antibiotics. The hok/sok locus forms dsRNA by RNA:RNA interactions between the toxin encoding mRNA and antitoxin non-coding RNA, and doxycycline has been reported to bind dsRNA structures and inhibit their cleavage/processing by the dsRNase, RNase III. This study investigated the antibacterial activities of doxycycline in hok/sok host bacteria cells, the effects on hok/sok-induced changes in growth and the mechanism(s) involved. Diverse strains of E. coli were transformed with hok/sok plasmids and assessed for doxycycline susceptibility and growth changes. The results show that the hok/sok locus increases bacterial susceptibility to doxycycline, which is more apparent in strains with more pronounced hok/sok-induced growth effects. The increased doxycycline susceptibility occurs despite β-lactam resistance imparted by hok/sok. Doxycycline was found to induce bacterial death in a manner phenotypically characteristic of Hok toxin expression, suggesting that it inhibits the toxin/antitoxin dsRNA degradation, leading to Hok toxin expression and cell death. In this way, doxycycline could counteract the multi-drug resistance plasmid maintenance/propagation, persistence and pathogenicity mechanisms associated with the hok/sok locus, which could potentially help in efforts to mitigate the rise of antimicrobial resistance.
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spelling doaj-art-1cebc798f6414a03bdb88de13fa0f5812025-08-20T02:17:05ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-01157e023563310.1371/journal.pone.0235633Doxycycline induces Hok toxin killing in host E. coli.Chinwe Uzoma ChukwudiLiam GoodThe antibacterial efficacy of the tetracycline antibiotics has been greatly reduced by the development of resistance, hence a decline in their clinical use. The hok/sok locus is a type I toxin/antitoxin plasmid stability element, often associated with multi-drug resistance plasmids, especially ESBL-encoding plasmids. It enhances host cell survivability and pathogenicity in stressful growth conditions, and increases bacterial tolerance to β-lactam antibiotics. The hok/sok locus forms dsRNA by RNA:RNA interactions between the toxin encoding mRNA and antitoxin non-coding RNA, and doxycycline has been reported to bind dsRNA structures and inhibit their cleavage/processing by the dsRNase, RNase III. This study investigated the antibacterial activities of doxycycline in hok/sok host bacteria cells, the effects on hok/sok-induced changes in growth and the mechanism(s) involved. Diverse strains of E. coli were transformed with hok/sok plasmids and assessed for doxycycline susceptibility and growth changes. The results show that the hok/sok locus increases bacterial susceptibility to doxycycline, which is more apparent in strains with more pronounced hok/sok-induced growth effects. The increased doxycycline susceptibility occurs despite β-lactam resistance imparted by hok/sok. Doxycycline was found to induce bacterial death in a manner phenotypically characteristic of Hok toxin expression, suggesting that it inhibits the toxin/antitoxin dsRNA degradation, leading to Hok toxin expression and cell death. In this way, doxycycline could counteract the multi-drug resistance plasmid maintenance/propagation, persistence and pathogenicity mechanisms associated with the hok/sok locus, which could potentially help in efforts to mitigate the rise of antimicrobial resistance.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0235633&type=printable
spellingShingle Chinwe Uzoma Chukwudi
Liam Good
Doxycycline induces Hok toxin killing in host E. coli.
PLoS ONE
title Doxycycline induces Hok toxin killing in host E. coli.
title_full Doxycycline induces Hok toxin killing in host E. coli.
title_fullStr Doxycycline induces Hok toxin killing in host E. coli.
title_full_unstemmed Doxycycline induces Hok toxin killing in host E. coli.
title_short Doxycycline induces Hok toxin killing in host E. coli.
title_sort doxycycline induces hok toxin killing in host e coli
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0235633&type=printable
work_keys_str_mv AT chinweuzomachukwudi doxycyclineinduceshoktoxinkillinginhostecoli
AT liamgood doxycyclineinduceshoktoxinkillinginhostecoli