scholarly journals Characterization of a Hyaluronic Acid Utilization Locus and Identification of Two Hyaluronate Lyases in a Marine Bacterium Vibrio alginolyticus LWW-9

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaoyi Wang ◽  
Ziwei Wei ◽  
Hao Wu ◽  
Yujiao Li ◽  
Feng Han ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Pathogenic Bacteria ◽  
Marine Bacterium ◽  
Opportunistic Pathogen ◽  
Bioinformatic Analysis ◽  
Industrial Applications ◽  
Biochemical Properties ◽  
Vibrio Alginolyticus ◽  
Host Cells ◽  
Marine Animals

Hyaluronic acid (HA) is a negatively charged and linear polysaccharide existing in the tissues and body fluids of all vertebrates. Some pathogenic bacteria target hyaluronic acid for adhesion and/or infection to host cells. Vibrio alginolyticus is an opportunistic pathogen related to infections of humans and marine animals, and the hyaluronic acid-degrading potential of Vibrio spp. has been well-demonstrated. However, little is known about how Vibrio spp. utilize hyaluronic acid. In this study, a marine bacterium V. alginolyticus LWW-9 capable of degrading hyaluronic acid has been isolated. Genetic and bioinformatic analysis showed that V. alginolyticus LWW-9 harbors a gene cluster involved in the degradation, transport, and metabolism of hyaluronic acid. Two novel PL8 family hyaluronate lyases, VaHly8A and VaHly8B, are the key enzymes for the degradation of hyaluronic acid. VaHly8A and VaHly8B have distinct biochemical properties, reflecting the adaptation of the strain to the changing parameters of the aquatic habitats and hosts. Based on genomic and functional analysis, we propose a model for the complete degradation of hyaluronic acid by V. alginolyticus LWW-9. Overall, our study expands our knowledge of the HA utilization paradigm within the Proteobacteria, and the two novel hyaluronate lyases are excellent candidates for industrial applications.

scholarly journals Pumilacidin-Like Lipopeptides Derived from Marine Bacterium Bacillus sp. Strain 176 Suppress the Motility of Vibrio alginolyticus

2017 ◽  
Vol 83 (12) ◽  
Author(s):  
Pengyuan Xiu ◽  
Rui Liu ◽  
Dechao Zhang ◽  
Chaomin Sun
Keyword(s):  
Cell Death ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Marine Bacterium ◽  
Vibrio Alginolyticus ◽  
Bacterial Motility ◽  
Great Promise ◽  
Content Type ◽  
Cyclic Lipopeptides

ABSTRACT Bacterial motility is a crucial factor during the invasion and colonization processes of pathogens, which makes it an attractive therapeutic drug target. Here, we isolated a marine bacterium (Vibrio alginolyticus strain 178) from a seamount in the tropical West Pacific that exhibits vigorous motility on agar plates and severe pathogenicity to zebrafish. We found that V. alginolyticus 178 motility was significantly suppressed by another marine bacterium, Bacillus sp. strain 176, isolated from the same niche. We isolated, purified, and characterized two different cyclic lipopeptides (CLPs) from Bacillus sp. 176 using high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectroscopy. The two related CLPs have a pumilacidin-like structure and were both effective inhibitors of V. alginolyticus 178 motility. The CLPs differ by only one methylene group in their fatty acid chains. In addition to motility suppression, the CLPs also induced cell aggregation in the medium and reduced adherence of V. alginolyticus 178 to glass substrates. Notably, upon CLP treatment, the expression levels of two V. alginolyticus flagellar assembly genes (flgA and flgP) dropped dramatically. Moreover, the CLPs inhibited biofilm formation in several other strains of pathogenic bacteria without inducing cell death. This study indicates that CLPs from Bacillus sp. 176 show promise as antimicrobial lead compounds targeting bacterial motility and biofilm formation with a low potential for eliciting antibiotic resistance. IMPORTANCE Pathogenic bacteria often require motility to establish infections and subsequently spread within host organisms. Thus, motility is an attractive therapeutic target for the development of novel antibiotics. We found that cyclic lipopeptides (CLPs) produced by marine bacterium Bacillus sp. strain 176 dramatically suppress the motility of the pathogenic bacterium Vibrio alginolyticus strain 178, reduce biofilm formation, and promote cellular aggregation without inducing cell death. These findings suggest that CLPs hold great promise as potential drug candidates targeting bacterial motility and biofilm formation with a low overall potential for triggering antibiotic resistance.

scholarly journals A Novel Neoagarotriose-Producing Agarase from the Marine Bacterium Gilvimarinus Agarilyticus JEA5

2020 ◽  
Author(s):  
Youngdeuk Lee ◽  
Eunyoung Jo ◽  
Yeon-Ju Lee ◽  
Hansol Choi ◽  
Tae-Yang Eom ◽  
...  
Keyword(s):  
Marine Bacterium ◽  
Industrial Applications ◽  
Biochemical Properties ◽  
Carbohydrate Binding ◽  
Ionization Mass ◽  
Coding Region ◽  
Protein Activity ◽  
Amino Acid Similarity ◽  
Chromatography Analysis ◽  
Layer Chromatography

Abstract Background The degradation of agar by bacterial agarases has many commercial and academic applications. We recently identified a novel neoagarotriose-producing β-agarase, Gaa16B, in the marine bacterium Gilvimarinus agarilyticus JEA5. This is the first report to describe neoagarotriose production from β-agarase.Results The Gaa16B agarase, which belongs to the glycoside hydrolase 16 (GH16) family of β-agarases, shows less than 70.9% amino acid similarity with previously characterized agarases. The coding region of Gaa16B is 1800 bp long, encoding 600 amino acids, and exhibits features typical of agarases belonging to the GH16 family. A recombinant Gaa16B lacking the carbohydrate binding region (rGaa16Bc) was overexpressed in Escherichia coli and purified as a maltose-binding protein (MBP) fusion protein. Activity assays revealed the optimal temperature and pH of rGaa16Bc to be 55 °C and pH 6–7, respectively, and the protein was highly stable at 55 °C for 90 min. Additionally, rGaa16Bc activity was strongly enhanced (2.3-fold) in the presence of 2.5 mM MnCl2. The Km and Vmax of rGaa16Bc for agarose were 6.4 mg/ml and 953 U/mg, respectively. Thin layer chromatography analysis revealed that rGaa16Bc can hydrolyze agarose into neoagarotetraose, neoagarotriose, and neoagarobiose, and the production of neoagarotriose by rGaa16Bc was successfully validated by high-resolution electrospray ionization mass spectrometry.Conclusion The biochemical properties of Gaa16B and the results of the hydrolytic pattern analysis suggest that Gaa16B could be useful to produce functional neoagaro-oligosaccharides for industrial applications.

scholarly journals Complete Genome Sequence of Vibrio alginolyticus ZJ-T

2016 ◽  
Vol 4 (5) ◽  
Author(s):  
Yiqin Deng ◽  
Chang Chen ◽  
Zhe Zhao ◽  
Xiaochun Huang ◽  
Yiying Yang ◽  
...  
Keyword(s):  
Genome Sequence ◽  
High Throughput ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
High Throughput Sequencing ◽  
Opportunistic Pathogen ◽  
Vibrio Alginolyticus ◽  
Negative Bacterium ◽  
Marine Animals ◽  
Gram Negative

Vibrio alginolyticus is a ubiquitous Gram-negative bacterium which is normally distributed in the coastal and estuarine environments. It has been suggested to be an opportunistic pathogen to both marine animals and humans, Here, the completed genome sequence of V. alginolyticus ZJ-T was determined by Illumina high-throughput sequencing.

The silent presence of Mycoplasma hominis in patients with prostate cancer

2020 ◽  
Vol 78 (7) ◽  
Author(s):  
Saman Saadat ◽  
Pezhman Karami ◽  
Mohammad Jafari ◽  
Mahdi Kholoujini ◽  
Zahra Rikhtegaran Tehrani ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Mycoplasma Hominis ◽  
Opportunistic Pathogen ◽  
Host Cells ◽  
Prostate Tissue ◽  
Control Group ◽  
P Value ◽  
Retrospective Case ◽  
Formalin Fixed Paraffin Embedded ◽  
Pcr Targeting

ABSTRACT Background Mycoplasma hominis, an opportunistic pathogen in human genitourinary tract, can cause chronic infection in the prostate. Intracellular survival of M. hominis leads to a prolonged presence in the host cells that can affect the cell's biological cycle. In the present study, we aimed to evaluate the frequency of M. hominis DNA in prostate tissue of Iranian patients with prostate cancer (PCa) in comparison to a control group with benign prostatic hyperplasia (BPH). Methods This research was a retrospective case-control study using 61 archived formalin-fixed paraffin-embedded (FFPE) blocks of prostate tissue from patients with PCa and 70 FFPE blocks of patients with BPH. Real-time PCR, targeting two different genes, 16S rRNA and yidC, in the M. hominis genome was performed for all specimens. Results Out of 61 blocks of prostate biopsy from patients with PCa, eight samples (13%) were positive for M. hominis, while the bacterium was not detected in any of the 70 blocks of patients with BPH (P value, 0.002). Conclusions The high frequency of M. hominis in patients with PCa likely shows a hidden role of the organism in prostate cancer during its chronic, apparently silent and asymptomatic colonization in prostate.

scholarly journals hfqPlays Important Roles in Virulence and Stress Adaptation in Cronobacter sakazakii ATCC 29544

2015 ◽  
Vol 83 (5) ◽  
pp. 2089-2098 ◽  
Author(s):  
Seongok Kim ◽  
Hyelyeon Hwang ◽  
Kwang-Pyo Kim ◽  
Hyunjin Yoon ◽  
Dong-Hyun Kang ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Soft Agar ◽  
Host Cells ◽  
Neonatal Meningitis ◽  
Animal Cells ◽  
Content Type ◽  
Flagellar Biosynthesis

Cronobacterspp. are opportunistic pathogens that cause neonatal meningitis and sepsis with high mortality in neonates. Despite the peril associated withCronobacterinfection, the mechanisms of pathogenesis are still being unraveled. Hfq, which is known as an RNA chaperone, participates in the interaction with bacterial small RNAs (sRNAs) to regulate posttranscriptionally the expression of various genes. Recent studies have demonstrated that Hfq contributes to the pathogenesis of numerous species of bacteria, and its roles are varied between bacterial species. Here, we tried to elucidate the role of Hfq inC. sakazakiivirulence. In the absence ofhfq,C. sakazakiiwas highly attenuated in disseminationin vivo, showed defects in invasion (3-fold) into animal cells and survival (103-fold) within host cells, and exhibited low resistance to hydrogen peroxide (102-fold). Remarkably, the loss ofhfqled to hypermotility on soft agar, which is contrary to what has been observed in other pathogenic bacteria. The hyperflagellated bacteria were likely to be attributable to the increased transcription of genes associated with flagellar biosynthesis in a strain lackinghfq. Together, these data strongly suggest thathfqplays important roles in the virulence ofC. sakazakiiby participating in the regulation of multiple genes.

Impact of fluoroquinolones and aminoglycosides on P. aeruginosa virulence factor production and cytotoxicity

2021 ◽  
Author(s):  
Daniel Morgan Foulkes ◽  
Keri McLean ◽  
Marta Sloniecka ◽  
Dominic Byrne ◽  
Atikah S Haneef ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Opportunistic Pathogen ◽  
World Health Organisation ◽  
Host Cells ◽  
World Health ◽  
Corneal Epithelial Cell ◽  
Cell Infection ◽  
Minimal Inhibitory Concentrations ◽  
Line Of Therapy

Infection from the opportunistic pathogen Pseudomonas aeruginosa is one of leading causes of disability and mortality worldwide and the world health organisation has listed it with the highest priority for the need of new antimicrobial therapies. P. aeruginosa strains responsible for the poorest clinical outcomes express either ExoS or ExoU, which are injected into target host cells via the type III secretion system (T3SS). ExoS is a bifunctional cytotoxin that promotes intracellular survival of invasive P. aeruginosa by preventing targeting of the bacteria to acidified intracellular compartments and lysosomal degradation. ExoU is a potent phospholipase which causes rapid destruction of host cell plasma membranes, leading to acute tissue damage and bacterial dissemination. Fluoroquinolones are usually employed as a first line of therapy as they have been shown to be more active against P. aeruginosa in vitro than other antimicrobial classes. However, their overuse over the past decade has caused alarming rates of antibiotic resistance to emerge. In certain clinical situations, aminoglycosides have been shown to be more effective then fluoroquinolones, despite their reduced potency towards P. aeruginosa in vitro. In this study, we evaluated the effects of fluoroquinolones (moxifloxacin and ciprofloxacin) and aminoglycosides (tobramycin and gentamycin) on T3SS expression and toxicity, in corneal epithelial cell infection models. We discovered tobramycin disrupted T3SS expression and inhibited both ExoS and ExoU mediated cytotoxicity, protecting infected HCE-T cells even at concentrations below the minimal inhibitory concentrations (MIC). Fluoroquinolones moxifloxacin and ciprofloxacin, however, upregulated the T3SS and in particular did not subvert the cytotoxic effects of ExoS and ExoU.

scholarly journals The Oleaginous Yeast Metschnikowia pulcherrima Displays Killer Activity against Avian-Derived Pathogenic Bacteria

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1227
Author(s):  
Robert H. Hicks ◽  
Mauro Moreno-Beltrán ◽  
Deborah Gore-Lloyd ◽  
Christopher J. Chuck ◽  
Daniel A. Henk
Keyword(s):  
Pathogenic Bacteria ◽  
Low Cost ◽  
Industrial Applications ◽  
Microbial Interactions ◽  
Bacterial Strains ◽  
Bacterial Killing ◽  
Killer Activity ◽  
Metschnikowia Pulcherrima ◽  
Livestock Health ◽  
Yeast Interactions

Metschnikowia pulcherrima is a non-conventional yeast with potential to be used in biotechnological processes, especially those involving low-cost feedstock exploitation and biocontrol applications. The combination of traits that supports these industrial applications in M. pulcherrima also makes it an attractive option to study in the context of livestock health. In this study, we examined the specific interactions between M. pulcherrima and multiple avian pathogenic bacteria. We tested individual bacteria–yeast interactions and bacterial combinations in both solid and liquid media and in variable nutrient environments. Across multiple isolates of M. pulcherrima, we observed different levels of antimicrobial activity, varying from supporting the growth of competing bacteria through suppression and bacterial killing, and we found that these responses varied depending on the bacterial strains and media. We identified multiple molecular routes, including proteins produced by M. pulcherrima strains, that acted to control these microbial interactions. Furthermore, protein screening revealed that M. pulcherrima strains were induced to produce proteins specifically when exposed to bacterial strains, suggesting that fine-tuned mechanisms allow M. pulcherrima to function as a potential lynchpin in a microbial community.

scholarly journals Bioinformatic Analysis of the Campylobacter jejuni Type VI Secretion System and Effector Prediction

2021 ◽  
Vol 12 ◽  
Author(s):  
Luca Robinson ◽  
Janie Liaw ◽  
Zahra Omole ◽  
Dong Xia ◽  
Arnoud H. M. van Vliet ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Variable Region ◽  
Pathogenicity Island ◽  
Bioinformatic Analysis ◽  
Secretion System ◽  
Open Reading Frames ◽  
Host Cells ◽  
Type Vi Secretion System ◽  
Bacterial Antagonism ◽  
Type Vi Secretion

The Type VI Secretion System (T6SS) has important roles relating to bacterial antagonism, subversion of host cells, and niche colonisation. Campylobacter jejuni is one of the leading bacterial causes of human gastroenteritis worldwide and is a commensal coloniser of birds. Although recently discovered, the T6SS biological functions and identities of its effectors are still poorly defined in C. jejuni. Here, we perform a comprehensive bioinformatic analysis of the C. jejuni T6SS by investigating the prevalence and genetic architecture of the T6SS in 513 publicly available genomes using C. jejuni 488 strain as reference. A unique and conserved T6SS cluster associated with the Campylobacter jejuni Integrated Element 3 (CJIE3) was identified in the genomes of 117 strains. Analyses of the T6SS-positive 488 strain against the T6SS-negative C. jejuni RM1221 strain and the T6SS-positive plasmid pCJDM202 carried by C. jejuni WP2-202 strain defined the “T6SS-containing CJIE3” as a pathogenicity island, thus renamed as Campylobacter jejuni Pathogenicity Island-1 (CJPI-1). Analysis of CJPI-1 revealed two canonical VgrG homologues, CJ488_0978 and CJ488_0998, harbouring distinct C-termini in a genetically variable region downstream of the T6SS operon. CJPI-1 was also found to carry a putative DinJ-YafQ Type II toxin-antitoxin (TA) module, conserved across pCJDM202 and the genomic island CJIE3, as well as several open reading frames functionally predicted to encode for nucleases, lipases, and peptidoglycan hydrolases. This comprehensive in silico study provides a framework for experimental characterisation of T6SS-related effectors and TA modules in C. jejuni.

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