Inoculum pretreatment affects bacterial survival, activity and catabolic gene expression during phytoremediation of diesel contaminated soil

Abstract Background Daptomycin (DAP) is a lipopeptide antibiotic targeting membrane anionic phospholipids (APLs) at the division septum, and resistance (DAP-R) has been linked to mutations in genes encoding i) the LiaFSR stress response system or its effector LiaX, and ii) cardiolipin synthase (Cls). Activation of the E. faecalis (Efs) LiaFSR response is associated with DAP-R and redistribution of APL microdomains away from the septum, and cardiolipin is predicted to be a major component of these APL microdomains. Efs harbors two putative cls genes, cls1 and cls2. While changes in Cls1 have been implicated in DAP-R, the exact roles of each enzyme in resistance are unknown. We aim to characterize the contributions of Cls1 and Cls2 in the development of DAP-R. Methods cls1 and cls2 were deleted individually and in tandem from DAP-S Efs OG117 and DAP-R Efs OG117∆liaX (a DAP-R derivative strain with an activated LiaFSR response). Mutants were characterized by DAP minimum inhibitory concentration (MIC) using E-test on Mueller-Hinton II agar and localization of APL microdomains with 10-N-nonyl-acridine orange staining. Quantitative PCR (qRT-PCR) was used to study gene expression profiles of cls1 and cls2 in Efs OG117∆liaX relative to Efs OG117 across the cell growth cycle. Results qRT-PCR revealed differential expression profiles of cls1 and cls2 associated with DAP-R. cls1 was highly upregulated in stationary phase concurrent with a decrease in cls2 expression. However, independent deletion of cls1 or cls2 in the DAP-R background resulted in no significant changes in DAP MICs or localization of APL microdomains (remaining non-septal). Further studies revealed that cls2 expression is upregulated upon deletion of cls1 in both the DAP-S and DAP-R background, suggesting a potential compensatory role for Cls2. Double deletion of both cls genes in the DAP-R strain decreased DAP MIC and restored the septal localization of APL microdomains. Conclusion Cls1 is the major and predominant enzyme involved in cell membrane adaptation associated with the development of DAP-R in E. faecalis. However, we describe a novel compensatory and overlapping role for cardiolipin synthases to ensure bacterial survival upon attack from antimicrobial peptides and related antibiotics. Disclosures Cesar A. Arias, MD, MSc, PhD, FIDSA, Entasis Therapeutics (Scientific Research Study Investigator)MeMed (Scientific Research Study Investigator)Merck (Grant/Research Support)

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Response of Fatty Acid Synthesis Genes to the Binding of Human Salivary Amylase by Streptococcus gordonii

Applied and Environmental Microbiology ◽

10.1128/aem.07071-11 ◽

2012 ◽

Vol 78 (6) ◽

pp. 1865-1875 ◽

Cited By ~ 7

Author(s):

Anna E. Nikitkova ◽

Elaine M. Haase ◽

M. Margaret Vickerman ◽

Steven R. Gill ◽

Frank A. Scannapieco

Keyword(s):

Gene Expression ◽

Fatty Acid ◽

Fatty Acid Synthesis ◽

Protein A ◽

Acid Synthesis ◽

Differentially Expressed ◽

Streptococcus Gordonii ◽

Bacterial Survival ◽

Salivary Amylase ◽

Content Type

ABSTRACTStreptococcus gordonii, an important primary colonizer of dental plaque biofilm, specifically binds to salivary amylase via the surface-associated amylase-binding protein A (AbpA). We hypothesized that a function of amylase binding toS. gordoniimay be to modulate the expression of chromosomal genes, which could influence bacterial survival and persistence in the oral cavity. Gene expression profiling by microarray analysis was performed to detect genes inS. gordoniistrain CH1 that were differentially expressed in response to the binding of purified human salivary amylase versus exposure to purified heat-denatured amylase. Selected genes found to be differentially expressed were validated by quantitative reverse transcription-PCR (qRT-PCR). Five genes from the fatty acid synthesis (FAS) cluster were highly (10- to 35-fold) upregulated inS. gordoniiCH1 cells treated with native amylase relative to those treated with denatured amylase. AnabpA-deficient strain ofS. gordoniiexposed to amylase failed to show a response in FAS gene expression similar to that observed in the parental strain. Predicted phenotypic effects of amylase binding toS. gordoniistrain CH1 (associated with increased expression of FAS genes, leading to changes in fatty acid synthesis) were noted; these included increased bacterial growth, survival at low pH, and resistance to triclosan. These changes were not observed in the amylase-exposedabpA-deficient strain, suggesting a role for AbpA in the amylase-induced phenotype. These results provide evidence that the binding of salivary amylase elicits a differential gene response inS. gordonii, resulting in a phenotypic adjustment that is potentially advantageous for bacterial survival in the oral environment.

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Regulation of catabolic gene expression in normal and degenerate human intervertebral disc cells: implications for the pathogenesis of intervertebral disc degeneration

Arthritis Research & Therapy ◽

10.1186/ar2693 ◽

2009 ◽

Vol 11 (3) ◽

pp. R65 ◽

Cited By ~ 105

Author(s):

S Jane Millward-Sadler ◽

Patrick W Costello ◽

Anthony J Freemont ◽

Judith A Hoyland

Keyword(s):

Gene Expression ◽

Intervertebral Disc ◽

Disc Degeneration ◽

Intervertebral Disc Degeneration ◽

Catabolic Gene ◽

Disc Cells

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Bacterial bioaugmentation enhances hydrocarbon degradation, plant colonization and gene expression in diesel‐contaminated soil

Physiologia Plantarum ◽

10.1111/ppl.13171 ◽

2020 ◽

Author(s):

Ume Ummara ◽

Sibgha Noreen ◽

Muhammad Afzal ◽

Parvaiz Ahmad

Keyword(s):

Gene Expression ◽

Contaminated Soil ◽

Hydrocarbon Degradation ◽

Plant Colonization

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In vitro inhibition of compression-induced catabolic gene expression in meniscal explants following treatment with IL-1 receptor antagonist

Journal of Orthopaedic Science ◽

10.1007/s00776-011-0026-6 ◽

2011 ◽

Vol 16 (2) ◽

pp. 212-220 ◽

Cited By ~ 10

Author(s):

Megan Leigh Killian ◽

Barbara Zielinska ◽

Tumul Gupta ◽

Tammy Lynn Haut Donahue

Keyword(s):

Gene Expression ◽

Receptor Antagonist ◽

Catabolic Gene ◽

In Vitro Inhibition

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Effects of hypoxia on anabolic and catabolic gene expression and DNA methylation in OA chondrocytes

Osteoarthritis and Cartilage ◽

10.1016/j.joca.2015.02.989 ◽

2015 ◽

Vol 23 ◽

pp. A196-A197

Author(s):

K. Alvarez ◽

M.C. de Andres ◽

A. Takahashi ◽

R.O. Oreffo

Keyword(s):

Gene Expression ◽

Dna Methylation ◽

Catabolic Gene ◽

Oa Chondrocytes

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Resilience in the Face of Uncertainty: Sigma Factor B Fine-Tunes Gene Expression To Support Homeostasis in Gram-Positive Bacteria

Applied and Environmental Microbiology ◽

10.1128/aem.00714-16 ◽

2016 ◽

Vol 82 (15) ◽

pp. 4456-4469 ◽

Cited By ~ 35

Author(s):

Claudia Guldimann ◽

Kathryn J. Boor ◽

Martin Wiedmann ◽

Veronica Guariglia-Oropeza

Keyword(s):

Gene Expression ◽

Sigma Factor ◽

Environmental Changes ◽

Regulation Of Gene Expression ◽

Bacterial Survival ◽

Gram Positive ◽

Content Type ◽

Gram Positive Bacteria ◽

Changing Environments ◽

The Face

ABSTRACTGram-positive bacteria are ubiquitous and diverse microorganisms that can survive and sometimes even thrive in continuously changing environments. The key to such resilience is the ability of members of a population to respond and adjust to dynamic conditions in the environment. In bacteria, such responses and adjustments are mediated, at least in part, through appropriate changes in the bacterial transcriptome in response to the conditions encountered. Resilience is important for bacterial survival in diverse, complex, and rapidly changing environments and requires coordinated networks that integrate individual, mechanistic responses to environmental cues to enable overall metabolic homeostasis. In many Gram-positive bacteria, a key transcriptional regulator of the response to changing environmental conditions is the alternative sigma factor σB. σBhas been characterized in a subset of Gram-positive bacteria, including the generaBacillus,Listeria, andStaphylococcus. Recent insight from next-generation-sequencing results indicates that σB-dependent regulation of gene expression contributes to resilience, i.e., the coordination of complex networks responsive to environmental changes. This review explores contributions of σBto resilience inBacillus,Listeria, andStaphylococcusand illustrates recently described regulatory functions of σB.

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