TY - JOUR
T1 - Elucidating the effect of iron acquisition systems in Klebsiella pneumoniae on susceptibility to the novel siderophore-cephalosporin cefiderocol
AU - Daoud, Lana
AU - Al-Marzooq, Farah
AU - Moubareck, Carole Ayoub
AU - Ghazawi, Akela
AU - Collyns, Timothy
N1 - Publisher Copyright:
© 2022 Daoud et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2022/12
Y1 - 2022/12
N2 - Background Cefiderocol (CFDC) is a novel siderophore-cephalosporin, effective against multidrug-resistant Gram-negative bacteria. As it has a siderophore side chain, it can utilize iron acquisition systems for penetration of the bacterial outer membrane. We aimed to elucidate the role of siderophores and iron uptake receptors in defining Klebsiella pneumoniae susceptibility to CFDC. Methods Initially, 103 K. pneumoniae strains were characterized for susceptibility to different antibiotics including CFDC. CFDC minimum inhibitory concentrations (MIC) were determined in iron-depleted and iron-enriched conditions. Iron uptake genes including siderophores, their receptors, ferric citrate (fecA) and iron uptake (kfu) receptors were detected by PCR in all the strains. For 10 selected strains, gene expression was tested in iron-depleted media with or without CFDC treatment and compared to expression in iron-enriched conditions. Results CFDC exhibited 96.1% susceptibility, being superior to all the other antibiotics (MIC50: 0.5 and MIC90: 4 μg/ml). Only three strains (2.9%) were intermediately susceptible and a pandrug resistant strain (0.97%) was resistant to CFDC (MIC: 8 and 256 μg/ml, respectively). The presence of kfu and fecA had a significant impact on CFDC MIC, especially when co-produced, and if coupled with yersiniabactin receptor (fyuA). CFDC MICs were negatively correlated with enterobactin receptor (fepA) expression and positively correlated with expression of kfu and fecA. Thus, fepA was associated with increased susceptibility to CFDC, while kfu and fecA were associated with reduced susceptibility to CFDC. CFDC MICs increased significantly in iron-enriched media, with reduced expression of siderophore receptors, hence, causing less drug uptake. Conclusion Iron acquisition systems have a significant impact on CFDC activity, and their altered expression is a factor leading to reduced susceptibility. Iron concentration is also a major player affecting CFDC susceptibility; therefore, it is essential to explore possible ways to improve the drug activity to facilitate its use to treat infections in iron-rich sites.
AB - Background Cefiderocol (CFDC) is a novel siderophore-cephalosporin, effective against multidrug-resistant Gram-negative bacteria. As it has a siderophore side chain, it can utilize iron acquisition systems for penetration of the bacterial outer membrane. We aimed to elucidate the role of siderophores and iron uptake receptors in defining Klebsiella pneumoniae susceptibility to CFDC. Methods Initially, 103 K. pneumoniae strains were characterized for susceptibility to different antibiotics including CFDC. CFDC minimum inhibitory concentrations (MIC) were determined in iron-depleted and iron-enriched conditions. Iron uptake genes including siderophores, their receptors, ferric citrate (fecA) and iron uptake (kfu) receptors were detected by PCR in all the strains. For 10 selected strains, gene expression was tested in iron-depleted media with or without CFDC treatment and compared to expression in iron-enriched conditions. Results CFDC exhibited 96.1% susceptibility, being superior to all the other antibiotics (MIC50: 0.5 and MIC90: 4 μg/ml). Only three strains (2.9%) were intermediately susceptible and a pandrug resistant strain (0.97%) was resistant to CFDC (MIC: 8 and 256 μg/ml, respectively). The presence of kfu and fecA had a significant impact on CFDC MIC, especially when co-produced, and if coupled with yersiniabactin receptor (fyuA). CFDC MICs were negatively correlated with enterobactin receptor (fepA) expression and positively correlated with expression of kfu and fecA. Thus, fepA was associated with increased susceptibility to CFDC, while kfu and fecA were associated with reduced susceptibility to CFDC. CFDC MICs increased significantly in iron-enriched media, with reduced expression of siderophore receptors, hence, causing less drug uptake. Conclusion Iron acquisition systems have a significant impact on CFDC activity, and their altered expression is a factor leading to reduced susceptibility. Iron concentration is also a major player affecting CFDC susceptibility; therefore, it is essential to explore possible ways to improve the drug activity to facilitate its use to treat infections in iron-rich sites.
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U2 - 10.1371/journal.pone.0277946
DO - 10.1371/journal.pone.0277946
M3 - Article
C2 - 36580460
AN - SCOPUS:85145242292
SN - 1932-6203
VL - 17
JO - PLoS ONE
JF - PLoS ONE
IS - 12 December
M1 - e0277946
ER -