נגישות
menu      
חיפוש מתקדם
תחביר
חפש...
הספר "אוצר וולקני"
אודות
תנאי שימוש
ניהול
קהילה:
אסיף מאגר המחקר החקלאי
פותח על ידי קלירמאש פתרונות בע"מ -
Enhanced Bacterial Fitness Under Residual Fluoroquinolone Concentrations Is Associated With Increased Gene Expression in Wastewater-Derived qnr Plasmid-Harboring Strains
Year:
2018
Source of publication :
Frontiers in Microbiology
Authors :
ג'ורקביץ', אדוארד
;
.
מראנו, רוברטו
;
.
סיטרין, אדי
;
.
קפלן, אלה
;
.
Volume :
9
Co-Authors:
Facilitators :
From page:
0
To page:
0
(
Total pages:
1
)
Abstract:

Plasmids harboring qnr genes confer resistance to low fluoroquinolone concentrations. These genes are of significant clinical, evolutionary and environmental importance, since they are widely distributed in a diverse array of natural and clinical environments. We previously extracted and sequenced a large (∼185 Kbp) qnrB-harboring plasmid, and several small (∼8 Kbp) qnrS-harboring plasmids, from Klebsiella pneumoniae isolates from municipal wastewater biosolids, and hypothesized that these plasmids provide host bacteria a selective advantage in wastewater treatment plants (WWTPs) that often contain residual concentrations of fluoroquinolones. The objectives of this study were therefore to determine the effect of residual fluoroquinolone concentrations on the growth kinetics of qnr plasmid-harboring bacteria; and on the copy number of qnr plasmids and expression of qnr genes. Electrotransformants harboring either one of the two types of plasmids could grow at ciprofloxacin concentrations exceeding 0.5 μg ml-1, but growth was significantly decreased at concentrations higher than 0.1 μg ml-1. In contrast, plasmid-free strains failed to grow even at 0.05 μg ml-1. No differences were observed in plasmid copy number under the tested ciprofloxacin concentrations, but qnr expression increased incrementally from 0 to 0.4 μg ml-1, suggesting that the transcription of this gene is regulated by antibiotic concentration. This study reveals that wastewater-derived qnr plasmids confer a selective advantage in the presence of residual fluoroquinolone concentrations and provides a mechanistic explanation for this phenomenon.

Note:
Related Files :
fitness
Plasmid
qnr genes
qPCR expression analysis
wastewater treatment
wastewater treatment
עוד תגיות
תוכן קשור
More details
DOI :
10.3389/fmicb.2018.01176
Article number:
1176
Affiliations:
Database:
גוגל סקולר
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
44599
Last updated date:
02/03/2022 17:27
Creation date:
03/11/2019 14:23
You may also be interested in
Scientific Publication
Enhanced Bacterial Fitness Under Residual Fluoroquinolone Concentrations Is Associated With Increased Gene Expression in Wastewater-Derived qnr Plasmid-Harboring Strains
9
Enhanced Bacterial Fitness Under Residual Fluoroquinolone Concentrations Is Associated With Increased Gene Expression in Wastewater-Derived qnr Plasmid-Harboring Strains

Plasmids harboring qnr genes confer resistance to low fluoroquinolone concentrations. These genes are of significant clinical, evolutionary and environmental importance, since they are widely distributed in a diverse array of natural and clinical environments. We previously extracted and sequenced a large (∼185 Kbp) qnrB-harboring plasmid, and several small (∼8 Kbp) qnrS-harboring plasmids, from Klebsiella pneumoniae isolates from municipal wastewater biosolids, and hypothesized that these plasmids provide host bacteria a selective advantage in wastewater treatment plants (WWTPs) that often contain residual concentrations of fluoroquinolones. The objectives of this study were therefore to determine the effect of residual fluoroquinolone concentrations on the growth kinetics of qnr plasmid-harboring bacteria; and on the copy number of qnr plasmids and expression of qnr genes. Electrotransformants harboring either one of the two types of plasmids could grow at ciprofloxacin concentrations exceeding 0.5 μg ml-1, but growth was significantly decreased at concentrations higher than 0.1 μg ml-1. In contrast, plasmid-free strains failed to grow even at 0.05 μg ml-1. No differences were observed in plasmid copy number under the tested ciprofloxacin concentrations, but qnr expression increased incrementally from 0 to 0.4 μg ml-1, suggesting that the transcription of this gene is regulated by antibiotic concentration. This study reveals that wastewater-derived qnr plasmids confer a selective advantage in the presence of residual fluoroquinolone concentrations and provides a mechanistic explanation for this phenomenon.

Scientific Publication
You may also be interested in