scholarly journals Iron and Zinc Regulate Expression of a Putative ABC Metal Transporter inCorynebacterium diphtheriae

2018 ◽  
Vol 200 (10) ◽  
pp. e00051-18 ◽  
Author(s):  
Eric D. Peng ◽  
Diana M. Oram ◽  
Marcos D. Battistel ◽  
Lindsey R. Lyman ◽  
Darón I. Freedberg ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Bacterial Colonization ◽  
Corynebacterium Diphtheriae ◽  
Heme Iron ◽  
Transport Systems ◽  
Upstream Region ◽  
Aerobic Bacterium ◽  
Dependent Manner ◽  
Content Type ◽  
Regulatory Factors

ABSTRACTCorynebacterium diphtheriae, a Gram-positive, aerobic bacterium, is the causative agent of diphtheria and cutaneous infections. While mechanisms required for heme iron acquisition are well known inC. diphtheriae, systems involved in the acquisition of other metals such as zinc and manganese remain poorly characterized. In this study, we identified a genetic region that encodes an ABC-type transporter (iutBCD) and that is flanked by two genes (iutAandiutE) encoding putative substrate binding proteins of the cluster 9 family, a related group of transporters associated primarily with the import of Mn and Zn. We showed that IutA and IutE are both membrane proteins with comparable Mn and Zn binding abilities. We demonstrated that theiutABCDgenes are cotranscribed and repressed in response to iron by the iron-responsive repressor DtxR. Transcription ofiutEwas positively regulated in response to iron availability in a DtxR-dependent manner and was repressed in response to Zn by the Zn-dependent repressor Zur. Electrophoretic mobility shift assays showed that DtxR does not bind to theiutEupstream region, which indicates that DtxR regulation ofiutEis indirect and that other regulatory factors controlled by DtxR are likely responsible for the iron-responsive regulation. Analysis of theiutEpromoter region identified a 50-bp sequence at the 3′ end of theiutDgene that is required for the DtxR-dependent and iron-responsive activation of theiutEgene. These findings indicate that transcription ofiutEis controlled by a complex mechanism that involves multiple regulatory factors whose activity is impacted by both Zn and Fe.IMPORTANCEVaccination against diphtheria prevents toxin-related symptoms but does not inhibit bacterial colonization of the human host by the bacterium. Thus,Corynebacterium diphtheriaeremains an important human pathogen that poses a significant health risk to unvaccinated individuals. The ability to acquire iron, zinc, and manganese is critical to the pathogenesis of many disease-causing organisms. Here, we describe a gene cluster inC. diphtheriaethat encodes a metal importer that is homologous to broadly distributed metal transport systems, some with important roles in virulence in other bacterial pathogens. Two metal binding components of the gene cluster encode surface exposed proteins, and studies of such proteins may guide the development of second-generation vaccines forC. diphtheriae.

scholarly journals Discovery of Gene Cluster for Mycosporine-Like Amino Acid Biosynthesis from Actinomycetales Microorganisms and Production of a Novel Mycosporine-Like Amino Acid by Heterologous Expression

2014 ◽  
Vol 80 (16) ◽  
pp. 5028-5036 ◽  
Author(s):  
Kiyoko T. Miyamoto ◽  
Mamoru Komatsu ◽  
Haruo Ikeda
Keyword(s):  
Amino Acid ◽  
Gene Cluster ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Dependent Manner ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria

ABSTRACTMycosporines and mycosporine-like amino acids (MAAs), including shinorine (mycosporine-glycine-serine) and porphyra-334 (mycosporine-glycine-threonine), are UV-absorbing compounds produced by cyanobacteria, fungi, and marine micro- and macroalgae. These MAAs have the ability to protect these organisms from damage by environmental UV radiation. Although no reports have described the production of MAAs and the corresponding genes involved in MAA biosynthesis from Gram-positive bacteria to date, genome mining of the Gram-positive bacterial database revealed that two microorganisms belonging to the orderActinomycetales,Actinosynnema mirumDSM 43827 andPseudonocardiasp. strain P1, possess a gene cluster homologous to the biosynthetic gene clusters identified from cyanobacteria. When the two strains were grown in liquid culture,Pseudonocardiasp. accumulated a very small amount of MAA-like compound in a medium-dependent manner, whereasA. mirumdid not produce MAAs under any culture conditions, indicating that the biosynthetic gene cluster ofA. mirumwas in a cryptic state in this microorganism. In order to characterize these biosynthetic gene clusters, each biosynthetic gene cluster was heterologously expressed in an engineered host,Streptomyces avermitilisSUKA22. Since the resultant transformants carrying the entire biosynthetic gene cluster controlled by an alternative promoter produced mainly shinorine, this is the first confirmation of a biosynthetic gene cluster for MAA from Gram-positive bacteria. Furthermore,S. avermitilisSUKA22 transformants carrying the biosynthetic gene cluster for MAA ofA. mirumaccumulated not only shinorine and porphyra-334 but also a novel MAA. Structure elucidation revealed that the novel MAA is mycosporine-glycine-alanine, which substitutesl-alanine for thel-serine of shinorine.

scholarly journals The ChrA-ChrS and HrrA-HrrS Signal Transduction Systems Are Required for Activation of the hmuO Promoter and Repression of the hemA Promoter in Corynebacterium diphtheriae

2007 ◽  
Vol 75 (5) ◽  
pp. 2421-2431 ◽  
Author(s):  
Lori A. Bibb ◽  
Carey A. Kunkle ◽  
Michael P. Schmitt
Keyword(s):  
Corynebacterium Diphtheriae ◽  
Heme Iron ◽  
Dependent Manner ◽  
Two Component System ◽  
Component System ◽  
Regulatory Systems ◽  
Component Systems ◽  
Two Component ◽  
Genes Encoding ◽  
Two Component Systems

ABSTRACT Transcription of the Corynebacterium diphtheriae hmuO gene, which encodes a heme oxygenase involved in heme iron utilization, is activated in a heme- or hemoglobin-dependent manner in part by the two-component system ChrA-ChrS. Mutation of either the chrA or the chrS gene resulted in a marked reduction of hemoglobin-dependent activation at the hmuO promoter in C. diphtheriae; however, it was observed that significant levels of hemoglobin-dependent expression were maintained in the mutants, suggesting that an additional activator is involved in regulation. A BLAST search of the C. diphtheriae genome sequence revealed a second two-component system, encoded by DIP2268 and DIP2267, that shares similarity with ChrS and ChrA, respectively; we have designated these genes hrrS (DIP2268) and hrrA (DIP2267). Analysis of hmuO promoter expression demonstrated that hemoglobin-dependent activity was fully abolished in strains from which both the chrA-chrS and the hrrA-hrrS two-component systems were deleted. Similarly, deletion of the sensor kinase genes chrS and hrrS or the genes encoding both of the response regulators chrA and hrrA also eliminated hemoglobin-dependent activation at the hmuO promoter. We also show that the regulators ChrA-ChrS and HrrA-HrrS are involved in the hemoglobin-dependent repression of the promoter upstream of hemA, which encodes a heme biosynthesis enzyme. Evidence for cross talk between the ChrA-ChrS and HrrA-HrrS systems is presented. In conclusion, these findings demonstrate that the ChrA-ChrS and HrrA-HrrS regulatory systems are critical for full hemoglobin-dependent activation at the hmuO promoter and also suggest that these two-component systems are involved in the complex mechanism of the regulation of heme homeostasis in C. diphtheriae.

scholarly journals Edwardsiella piscicidaType III Secretion System Effector EseK Inhibits Mitogen-Activated Protein Kinase Phosphorylation and Promotes Bacterial Colonization in Zebrafish Larvae

2018 ◽  
Vol 86 (9) ◽  
Author(s):  
Huifang Cao ◽  
Fajun Han ◽  
Jinchao Tan ◽  
Mingyu Hou ◽  
Yuanxing Zhang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Bacterial Colonization ◽  
Mapk Signaling ◽  
Host Cells ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Secretion Systems ◽  
Content Type ◽  
T3ss Effector ◽  
Mitogen Activated Protein

ABSTRACTBacteria utilize type III secretion systems (T3SS) to deliver effectors directly into host cells. Hence, it is very important to identify the functions of bacterial (T3SS) effectors to understand host-pathogen interactions.Edwardsiella piscicidaencodes a functional T3SS effector, EseK, which can be translocated into host cells and affect bacterial loads. Here, it was demonstrated that aneseKmutant (the ΔeseKmutant) significantly increased the phosphorylation levels of p38α, c-Jun NH2-terminal kinases (JNK), and extracellular signal-regulated protein kinases 1/2 (ERK1/2) in HeLa cells. Overexpression of EseK directly inhibited mitogen-activated protein kinase (MAPK) signaling pathways in HEK293T cells. The ΔeseKmutant consistently promoted the phosphorylation of MAPKs in zebrafish larva infection models. Further, it was shown that the ΔeseKmutant increased the expression of tumor necrosis factor alpha (TNF-α) in an MAPK-dependent manner. Importantly, the EseK-mediated inhibition of MAPKsin vivoattenuated bacterial clearance in larvae. Taken together, this work reveals that theE. piscicidaT3SS effector EseK promotes bacterial infection by inhibiting MAPK activation, which provides insights into the molecular pathogenesis ofE. piscicidain fish.

scholarly journals A Novel Angular Dioxygenase Gene Cluster Encoding 3-Phenoxybenzoate 1′,2′-Dioxygenase in Sphingobium wenxiniae JZ-1

2014 ◽  
Vol 80 (13) ◽  
pp. 3811-3818 ◽  
Author(s):  
Chenghong Wang ◽  
Qing Chen ◽  
Rui Wang ◽  
Chao Shi ◽  
Xin Yan ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Heme Iron ◽  
Transcriptional Level ◽  
Content Type ◽  
Type Iv ◽  
Reductase Gene ◽  
Wide Range ◽  
Dioxygenase Gene ◽  
Sphingomonas Wittichii ◽  
Angular Dioxygenase

ABSTRACTSphingobium wenxiniaeJZ-1 utilizes a wide range of pyrethroids and their metabolic product, 3-phenoxybenzoate, as sources of carbon and energy. A mutant JZ-1 strain, MJZ-1, defective in the degradation of 3-phenoxybenzoate was obtained by successive streaking on LB agar. Comparison of the draft genomes of strains JZ-1 and MJZ-1 revealed that a 29,366-bp DNA fragment containing a putative angular dioxygenase gene cluster (pbaA1A2B) is missing in strain MJZ-1. PbaA1, PbaA2, and PbaB share 65%, 52%, and 10% identity with the corresponding α and β subunits and the ferredoxin component of dioxin dioxygenase fromSphingomonas wittichiiRW1, respectively. Complementation ofpbaA1A2Bin strain MJZ-1 resulted in the active 3-phenoxybenzoate 1′,2′-dioxygenase, but the enzyme activity inEscherichia coliwas achieved only through the coexpression ofpbaA1A2Band a glutathione reductase (GR)-type reductase gene,pbaC, indicating that the 3-phenoxybenzoate 1′,2′-dioxygenase belongs to a type IV Rieske non-heme iron aromatic ring-hydroxylating oxygenase system consisting of a hetero-oligomeric oxygenase, a [2Fe-2S]-type ferredoxin, and a GR-type reductase. ThepbaCgene is not located in the immediate vicinity ofpbaA1A2B. 3-Phenoxybenzoate 1′,2′-dioxygenase catalyzes the hydroxylation in the 1′ and 2′ positions of the benzene moiety of 3-phenoxybenzoate, yielding 3-hydroxybenzoate and catechol. Transcription ofpbaA1A2BandpbaCwas induced by 3-phenoxybenzoate, but the transcriptional level ofpbaCwas far less than that ofpbaA1A2B, implying the possibility that PbaC may not be the only reductase that can physiologically transfer electrons to PbaA1A2B in strain JZ-1. Some GR-type reductases from other sphingomonad strains could also transfer electrons to PbaA1A2B, suggesting that PbaA1A2B has a low specificity for reductase.

scholarly journals Molecular and Functional Analysis of the Type IV Pilus Gene Cluster inStreptococcus sanguinisSK36

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
Yi-Ywan M. Chen ◽  
Yi-Chien Chiang ◽  
Tzu-Ying Tseng ◽  
Hui-Yu Wu ◽  
Yueh-Ying Chen ◽  
...  
Keyword(s):  
Surface Structure ◽  
Gene Cluster ◽  
Type Iv Pili ◽  
Oral Microbiome ◽  
Host Cells ◽  
Dependent Manner ◽  
Content Type ◽  
Streptococcus Sanguinis ◽  
Dental Biofilm ◽  
Type Iv

ABSTRACTStreptococcus sanguinis, dominant in the oral microbiome, is the only known streptococcal species possessing apilgene cluster for the biosynthesis of type IV pili (Tfp). Although this cluster is commonly present in the genome ofS. sanguinis, most of the strains do not express Tfp-mediated twitching motility. Thus, this study was designed to investigate the biological functions encoded by the cluster in the twitching-negative strainS. sanguinisSK36. We found that the cluster was transcribed as an operon, with three promoters located 5′ to the cluster and one in the intergenic region between SSA_2307 and SSA_2305. Studies using promoter-catfusion strains revealed that the transcription of the cluster was mainly driven by the distal 5′ promoter, which is located more than 800 bases 5′ to the first gene of the cluster, SSA_2318. Optimal expression of the cluster occurred at the early stationary growth phase in a CcpA-dependent manner, although a CcpA-binding consensus is absent in the promoter region. Expression of the cluster resulted in a short hairlike surface structure under transmission electron microscopy. Deletion of the putative pilin genes (SSA_2313 to SSA_2315) abolished the biosynthesis of this structure and significantly reduced the adherence of SK36 to HeLa and SCC-4 cells. Mutations in thepilgenes downregulated biofilm formation byS. sanguinisSK36. Taken together, the results demonstrate that Tfp of SK36 are important for host cell adherence, but not for motility, and that expression of thepilcluster is subject to complex regulation.IMPORTANCEThe proteins and assembly machinery of the type IV pili (Tfp) are conserved throughout bacteria and archaea, and yet the function of this surface structure differs from species to species and even from strain to strain. As seen inStreptococcus sanguinisSK36, the expression of the Tfp gene cluster results in a hairlike surface structure that is much shorter than the typical Tfp. This pilus is essential for the adherence of SK36 but is not involved in motility. Being a member of the highly diverse dental biofilm, perhapsS. sanguiniscould more effectively utilize this structure to adhere to host cells and to interact with other microbes within the same niche.

scholarly journals Dual Zinc Transporter Systems in Vibrio cholerae Promote Competitive Advantages over Gut Microbiome

2015 ◽  
Vol 83 (10) ◽  
pp. 3902-3908 ◽  
Author(s):  
Ying Sheng ◽  
Fenxia Fan ◽  
Owen Jensen ◽  
Zengtao Zhong ◽  
Biao Kan ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Gene Clusters ◽  
Bioinformatic Analysis ◽  
Zinc Transporter ◽  
Zinc Homeostasis ◽  
Transport Systems ◽  
Growth Defect ◽  
Dependent Manner ◽  
Content Type ◽  
Transporter Systems

Zinc is an essential trace metal required for numerous cellular processes in all forms of life. In order to maintain zinc homeostasis, bacteria have developed several transport systems to regulate its uptake. In this study, we investigated zinc transport systems in the enteric pathogenVibrio cholerae, the causative agent of cholera. Bioinformatic analysis predicts that two gene clusters, VC2081 to VC2083 (annotated as zinc utilization genesznuABC) and VC2551 to VC2555 (annotated aszinc-regulatedgeneszrgABCDE), are regulated by the putative zinc uptake regulator Zur. Using promoter reporter and biochemical assays, we confirmed that Zur repressesznuABCandzrgABCDEpromoters in a Zn2+-dependent manner. Under Zn2+-limiting conditions, we found that mutations in either theznuABCorzrgABCDEgene cluster affect bacterial growth, withznuABCmutants displaying a more severe growth defect, suggesting that both ZnuABC and ZrgABCDE are involved in Zn2+uptake and that ZnuABC plays the predominant role. Furthermore, we reveal that ZnuABC and ZrgABCDE are important forV. choleraecolonization in both infant and adult mouse models, particularly in the presence of other intestinal microbiota. Collectively, our studies indicate that these two zinc transporter systems play vital roles in maintaining zinc homeostasis duringV. choleraegrowth and pathogenesis.

scholarly journals The Yfe and Feo Transporters Are Involved in Microaerobic Growth and Virulence of Yersinia pestis in Bubonic Plague

2012 ◽  
Vol 80 (11) ◽  
pp. 3880-3891 ◽  
Author(s):  
Jacqueline D. Fetherston ◽  
Ildefonso Mier ◽  
Helena Truszczynska ◽  
Robert D. Perry
Keyword(s):  
Yersinia Pestis ◽  
Double Mutant ◽  
Lethal Dose ◽  
Growth Conditions ◽  
Transport Systems ◽  
Growth Defect ◽  
Dependent Manner ◽  
Bubonic Plague ◽  
Pneumonic Plague ◽  
Content Type

ABSTRACTThe Yfe/Sit and Feo transport systems are important for the growth of a variety of bacteria. InYersinia pestis, single mutations in eitheryfeorfeoresult in reduced growth under static (limited aeration), iron-chelated conditions, while ayfe feodouble mutant has a more severe growth defect. These growth defects were not observed when bacteria were grown under aerobic conditions or in strains capable of producing the siderophore yersiniabactin (Ybt) and the putative ferrous transporter FetMP. BothfetPand a downstream locus (flpforfetlinkedphenotype) were required for growth of ayfe feo ybtmutant under static, iron-limiting conditions. AnfeoBmutation alone had no effect on the virulence ofY. pestisin either bubonic or pneumonic plague models. Anfeo yfedouble mutant was still fully virulent in a pneumonic plague model but had an ∼90-fold increase in the 50% lethal dose (LD50) relative to the Yfe+Feo+parent strain in a bubonic plague model. Thus, Yfe and Feo, in addition to Ybt, play an important role in the progression of bubonic plague. Finally, we examined the factors affecting the expression of thefeooperon inY. pestis. Under static growth conditions, theY. pestis feo::lacZfusion was repressed by iron in a Fur-dependent manner but not in cells grown aerobically. Mutations infeoC,fnr,arcA,oxyR, orrstABhad no significant effect on transcription of theY. pestis feopromoter. Thus, the factor(s) that prevents repression by Fur under aerobic growth conditions remains to be identified.

scholarly journals Global Regulatory Roles of the Histidine-Responsive Transcriptional Repressor HutC in Pseudomonas fluorescens SBW25

2020 ◽  
Vol 202 (13) ◽  
Author(s):  
Naran Naren ◽  
Xue-Xian Zhang
Keyword(s):  
Dna Binding ◽  
Pseudomonas Fluorescens ◽  
Bacterial Colonization ◽  
Transcriptional Repressor ◽  
Binding Domain ◽  
Phenotypic Characterization ◽  
Growth Defect ◽  
Dependent Manner ◽  
Rna Seq ◽  
Content Type

ABSTRACT HutC is known as a transcriptional repressor specific for histidine utilization (hut) genes in Gram-negative bacteria, including Pseudomonas fluorescens SBW25. However, its precise mode of protein-DNA interactions hasn’t been examined with purified HutC proteins. Here, we performed electrophoretic mobility shift assay (EMSA) and DNase I footprinting using His6-tagged HutC and biotin-labeled probe of the hut promoter (PhutU). Results revealed a complex pattern of HutC oligomerization, and the specific protein-DNA interaction is disrupted by urocanate, a histidine derivative, in a concentration-dependent manner. Next, we searched for putative HutC-binding sites in the SBW25 genome. This led to the identification of 143 candidate targets with a P value less than 10−4. HutC interaction with eight selected candidate sites was subsequently confirmed by EMSA analysis, including the type IV pilus assembly protein PilZ, phospholipase C (PlcC) for phosphatidylcholine hydrolyzation, and key regulators of cellular nitrogen metabolism (NtrBC and GlnE). Finally, an isogenic hutC deletion mutant was subjected to transcriptome sequencing (RNA-seq) analysis and phenotypic characterization. When bacteria were grown on succinate and histidine, hutC deletion caused upregulation of 794 genes and downregulation of 525 genes at a P value of <0.05 with a fold change cutoff of 2.0. The hutC mutant displayed an enhanced spreading motility and pyoverdine production in laboratory media, in addition to the previously reported growth defect on the surfaces of plants. Together, our data indicate that HutC plays global regulatory roles beyond histidine catabolism through low-affinity binding with operator sites located outside the hut locus. IMPORTANCE HutC in Pseudomonas is a representative member of the GntR/HutC family of transcriptional regulators, which possess a N-terminal winged helix-turn-helix (wHTH) DNA-binding domain and a C-terminal substrate-binding domain. HutC is generally known to repress expression of histidine utilization (hut) genes through binding to the PhutU promoter with urocanate (the first intermediate of the histidine degradation pathway) as the direct inducer. Here, we first describe the detailed molecular interactions between HutC and its PhutU target site in a plant growth-promoting bacterium, P. fluorescens SBW25, and further show that HutC possesses specific DNA-binding activities with many targets in the SBW25 genome. Subsequent RNA-seq analysis and phenotypic assays revealed an unexpected global regulatory role of HutC for successful bacterial colonization in planta.

scholarly journals The Enterohemorrhagic Escherichia coli Effector EspW Triggers Actin Remodeling in a Rac1-Dependent Manner

2017 ◽  
Vol 85 (9) ◽  
Author(s):  
Pamela Sandu ◽  
Valerie F. Crepin ◽  
Hauke Drechsler ◽  
Andrew D. McAinsh ◽  
Gad Frankel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Colonization ◽  
Ectopic Expression ◽  
Bacterial Attachment ◽  
Effector Proteins ◽  
Enterohemorrhagic Escherichia Coli ◽  
Actin Dynamics ◽  
Dependent Manner ◽  
Nucleotide Exchange ◽  
Content Type

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) is a diarrheagenic pathogen that colonizes the gut mucosa and induces attaching-and-effacing lesions. EHEC employs a type III secretion system (T3SS) to translocate 50 effector proteins that hijack and manipulate host cell signaling pathways, which allow bacterial colonization and subversion of immune responses and disease progression. The aim of this study was to characterize the T3SS effector EspW. We found espW in the sequenced O157:H7 and non-O157 EHEC strains as well as in Shigella boydii. Furthermore, a truncated version of EspW, containing the first 206 residues, is present in EPEC strains belonging to serotype O55:H7. Screening a collection of clinical EPEC isolates revealed that espW is present in 52% of the tested strains. We report that EspW modulates actin dynamics in a Rac1-dependent manner. Ectopic expression of EspW results in formation of unique membrane protrusions. Infection of Swiss cells with an EHEC espW deletion mutant induces a cell shrinkage phenotype that could be rescued by Rac1 activation via expression of the bacterial guanine nucleotide exchange factor, EspT. Furthermore, using a yeast two-hybrid screen, we identified the motor protein Kif15 as a potential interacting partner of EspW. Kif15 and EspW colocalized in cotransfected cells, while ectopically expressed Kif15 localized to the actin pedestals following EHEC infection. The data suggest that Kif15 recruits EspW to the site of bacterial attachment, which in turn activates Rac1, resulting in modifications of the actin cytoskeleton that are essential to maintain cell shape during infection.

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

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