Global regulator DksA modulates virulence of <i>Acinetobacter baumannii</i>

Kim, Nayeong; Son, Joo Hee; Kim, Kyeong-Min; Kim, Hyo Jeong; Kim, Yoo Jeong; Shin, Minsang; Lee, Je Chul

doi:10.1080/21505594.2021.1995253

Cited by 8 publications

(6 citation statements)

References 55 publications

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“…The present study demonstrated that ∆ dksA mutants of clinical 1656-2 exhibited more morphological heterogeneity than the WT strain. Previous studies have reported that ∆ dksA mutant and (p)ppGpp-deficient mutant strains exhibited more morphological heterogeneity than the WT A. baumannii ATCC 17978 strain [ 20 , 25 ]. The (p)ppGpp-deficient and ∆ dksA mutants in E. coli also exhibited a more filamentous morphology than the WT strain [ 16 ].…”

Section: Discussionmentioning

confidence: 99%

DksA Modulates Antimicrobial Susceptibility of Acinetobacter baumannii

et al. 2021

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The stringent response regulators, (p)ppGpp and DksA, modulate various genes involved in physiological processes, virulence, and antimicrobial resistance in pathogenic bacteria. This study investigated the role of DksA in the antimicrobial susceptibility of Acinetobacter baumannii. The ∆dksA mutant (KM0248D) of A. baumannii ATCC 17978 and its complemented strain (KM0248C) were used, in addition to the ∆dksA mutant strain (NY0298D) of clinical 1656-2 strain. The microdilution assay was used to determine the minimum inhibitory concentrations (MICs) of antimicrobial agents. Quantitative real-time PCR was performed to analyze the expression of genes associated with efflux pumps. The KM0248D strain exhibited an increase of MICs to quinolones and tetracyclines, whereas KM0248D and NY0298D strains exhibited a decrease of MICs to aminoglycosides. The expression of genes associated with efflux pumps, including adeB, adeI/J, abeM, and/or tetA, was upregulated in both ∆dksA mutant strains. The deletion of dksA altered bacterial morphology in the clinical 1656-2 strain. In conclusion, DksA modulates the antimicrobial susceptibility of A. baumannii. The ∆dksA mutant strains of A. baumannii upregulate efflux pump gene expression, whereas (p)ppGpp-deficient mutants downregulate efflux pump gene expression. (p)ppGpp and DksA conduct opposite roles in the antimicrobial susceptibility of A. baumannii via efflux pump gene regulation.

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Section: Discussionmentioning

confidence: 99%

DksA Modulates Antimicrobial Susceptibility of Acinetobacter baumannii

et al. 2021

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“…It is one of the earliest research topics in multimodal machine learning (Zhang et al 2020). Transformers have been widely used in multimodal tasks such as Visual-Language Pre-training (Kim et al 2021;Li et al 2021) and Multimodal Named Entity Recognition (Yu et al 2020;Sun et al 2021) because they can mine the internal relationships among long sequences via self-attention mechanisms.…”

Section: Methodsmentioning

confidence: 99%

“…Transformer's (Vaswani et al 2017) powerful feature extraction capability results in the excellent performance of the same model across multiple modalities. Recent studies using the Transformer architecture on multimodal tasks have yielded promising results (Kim et al 2021;Li et al 2021;Sun et al 2021). We reference the advanced multimodal method in CV and NLP, using Transformer to combine complementary information from spectral and photometric images.…”

Section: Introductionmentioning

confidence: 99%

Deep Multimodal Networks for M-type Star Classification with Paired Spectrum and Photometric Image

Gao¹,

Chen²,

Wei³

et al. 2023

PASP

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Traditional stellar classification methods include spectral and photometric classification separately. Although satisfactory results can be achieved, the accuracy could be improved. In this paper, we pioneer a novel approach to deeply fuse the spectra and photometric images of the sources in an advanced multimodal network to enhance the model’s discriminatory ability. We use Transformer as the fusion module and apply a spectrum–image contrastive loss function to enhance the consistency of the spectrum and photometric image of the same source in two different feature spaces. We perform M-type stellar subtype classification on two data sets with high and low signal-to-noise ratio (S/N) spectra and corresponding photometric images, and the F1-score achieves 95.65% and 90.84%, respectively. In our experiments, we prove that our model effectively utilizes the information from photometric images and is more accurate than advanced spectrum and photometric image classifiers. Our contributions can be summarized as follows: (1) We propose an innovative idea for stellar classification that allows the model to simultaneously consider information from spectra and photometric images. (2) We discover the challenge of fusing low-S/N spectra and photometric images in the Transformer and provide a solution. (3) The effectiveness of Transformer for spectral classification is discussed for the first time and will inspire more Transformer-based spectral classification models.

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“…DksA also plays a key role in the control of virulence-related genes. In some pathogenic bacteria ( e.g., Escherichia coli , H. ducreyi , P. aeruginosa , S. enterica , Vibrio cholerae and A. baumannii ) dksA mutants are less virulent than the wild type both in vitro and in vivo 18 , 20 – 25 .…”

Section: Introductionmentioning

confidence: 99%

The Pseudomonas aeruginosa DksA1 protein is involved in H2O2 tolerance and within-macrophages survival and can be replaced by DksA2

Fortuna

Collalto

Schiaffi³

et al. 2022

Sci Rep

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In Gram-negative pathogens, the stringent response regulator DksA controls the expression of hundreds of genes, including virulence-related genes. Interestingly, Pseudomonas aeruginosa has two functional DksA paralogs: DksA1 is constitutively expressed and has a zinc-finger motif, while DksA2 is expressed only under zinc starvation conditions and does not contain zinc. DksA1 stimulates the production of virulence factors in vitro and is required for full pathogenicity in vivo. DksA2 can replace these DksA1 functions. Here, the role of dksA paralogs in P. aeruginosa tolerance to H2O2-induced oxidative stress has been investigated. The P. aeruginosa dksA1 dksA2 mutant showed impaired H2O2 tolerance in planktonic and biofilm-growing cultures and increased susceptibility to macrophages-mediated killing compared to the wild type. Complementation with either dksA1 or dksA2 genes restored the wild type phenotypes. The DksA-dependent tolerance to oxidative stress involves, at least in part, the positive transcriptional control of both katA and katE catalase-encoding genes. These data support the hypothesis that DksA1 and DksA2 are eco-paralogs with indistinguishable function but optimal activity under different environmental conditions, and highlight their mutual contribution to P. aeruginosa virulence.

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Global regulator DksA modulates virulence of Acinetobacter baumannii

Cited by 8 publications

References 55 publications

DksA Modulates Antimicrobial Susceptibility of Acinetobacter baumannii

DksA Modulates Antimicrobial Susceptibility of Acinetobacter baumannii

Deep Multimodal Networks for M-type Star Classification with Paired Spectrum and Photometric Image

The Pseudomonas aeruginosa DksA1 protein is involved in H2O2 tolerance and within-macrophages survival and can be replaced by DksA2

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