scholarly journals Identification and Analysis of Staphylococcus aureus Components Expressed by a Model System of Growth in Serum

2001 ◽  
Vol 69 (8) ◽  
pp. 5198-5202 ◽  
Author(s):  
Michael D. Wiltshire ◽  
Simon J. Foster
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Model System ◽  
Surface Proteins ◽  
Lysine Biosynthesis ◽  
Genes Encoding ◽  
Peptide Biosynthesis ◽  
Microaerobic Conditions

ABSTRACT A model system mimicking Staphylococcus aureusbacteremia was developed by growth in serum under microaerobic conditions. Eight genes induced by growth in serum were identified, including an antimicrobial peptide biosynthesis locus, amino acid biosynthetic loci, and genes encoding putative surface proteins. Nine independent insertions were found in the major lysine biosynthesis operon, which encodes eight genes, is repressed by lysine in vitro, and is expressed in vivo.

scholarly journals A genomic and proteomic analysis of surface proteins in bovine-adapted lineages of Staphylococcus aureus

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Shauna D. Drumm ◽  
Rebecca Owens ◽  
Jennifer Mitchell ◽  
Orla M. Keane
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Surface Proteins ◽  
Host Cells ◽  
Mass Spectrometry Analysis ◽  
In Vitro Assays ◽  
Immune Recognition ◽  
Independent Manner ◽  
Genes Encoding

In Ireland, Staphylococcus aureus is the most common cause of intramammary infection (IMI) in cattle with the bovine-adapted lineages CC151 and CC97 most commonly found. Surface proteins play a major role in establishing and maintaining the infection. A previous study revealed that a strain from the CC151 lineage showed significant decay in genes encoding predicted surface proteins. Twenty-three S. aureus strains, twelve belonging to CC151 and eleven belonging to CC97, isolated from clinical IMI, were sequenced and genes encoding cell wall anchored (CWA) proteins predicted. Analysis showed that a minority of genes encoding putative CWA proteins were intact in the CC151 strains compared to CC97. Of the 26 known CWA proteins in S. aureus, the CC151 strains only encoded 10 intact genes while CC97 encoded on average 18 genes. Also within the CC97 lineage, the repertoire of genes varied depending on individual strains, with strains encoding between 17-20 intact genes. Although CC151 is reported to internalize within bovine host cells, it does so in a fibronectin-binding protein (FnBPA and FnBPB) independent manner. In-vitro assays were performed and results showed that strains from CC151, and surprisingly also CC97, weakly bound bovine fibronectin and that the FnBPs were poorly expressed in both these lineages. Mass spectrometry analysis of cell wall extracts revealed that SdrE and AdsA were the most highly expressed CWA proteins in both lineages. These results demonstrate significant differences between CC151 and CC97 in their repertoire of genes encoding CWA proteins, which may impact immune recognition of these strains and their interactions with host cells.

scholarly journals Increase in Campylobacter jejuni Invasion of Intestinal Epithelial Cells under Low-Oxygen Coculture Conditions That Reflect theIn VivoEnvironment

2012 ◽  
Vol 80 (5) ◽  
pp. 1690-1698 ◽  
Author(s):  
Dominic C. Mills ◽  
Ozan Gundogdu ◽  
Abdi Elmi ◽  
Mona Bajaj-Elliott ◽  
Peter W. Taylor ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Model System ◽  
Apical Surface ◽  
Intestinal Epithelial ◽  
Low Oxygen ◽  
Aerobic Conditions ◽  
Content Type ◽  
Microaerobic Conditions

ABSTRACTCampylobacter jejuniinfection often results in bloody, inflammatory diarrhea, indicating bacterial disruption and invasion of the intestinal epithelium. WhileC. jejuniinfection can be reproducedin vitrousing intestinal epithelial cell (IEC) lines, low numbers of bacteria invading IECs do not reflect these clinical symptoms. Performingin vitroassays under atmospheric oxygen conditions neither is optimal for microaerophilicC. jejuninor reflects the low-oxygen environment of the intestinal lumen. A vertical diffusion chamber (VDC) model system creates microaerobic conditions at the apical surface and aerobic conditions at the basolateral surface of cultured IECs, producing anin vitrosystem that closely mimicsin vivoconditions in the human intestine. Ninefold increases in interacting and 80-fold increases in intracellularC. jejuni11168H wild-type strain bacteria were observed after 24-h coculture with Caco-2 IECs in VDCs under microaerobic conditions at the apical surface, compared to results under aerobic conditions. Increased bacterial interaction was matched by an enhanced and directional host innate immune response, particularly an increased basolateral secretion of the proinflammatory chemokine interleukin-8 (IL-8). Analysis of the invasive ability of a nonmotileC. jejuni11168HrpoNmutant in the VDC model system indicates that motility is an important factor in the early stages of bacterial invasion. The first report of the use of a VDC model system for studying the interactions of an invasive bacterial pathogen with IECs demonstrates the importance of performing such experiments under conditions that represent thein vivosituation and will allow novel insights intoC. jejunipathogenic mechanisms.

scholarly journals Rapid and Broad Immune Efficacy of a Recombinant Five-Antigen Vaccine against Staphylococcus aureus Infection in Animal Models

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 134 ◽  
Author(s):  
Hao Zeng ◽  
Feng Yang ◽  
Qiang Feng ◽  
Jinyong Zhang ◽  
Jiang Gu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Severe Disease ◽  
Lethal Dose ◽  
Protein A ◽  
Surface Proteins ◽  
Staphylococcal Protein A ◽  
Humoral Immune ◽  
Aureus Infection

Staphylococcus aureus (S. aureus) is a leading cause of both healthcare-and community-associated infections globally, which result in severe disease and readily developing antibiotic resistance. Developing an efficacious vaccine against S. aureus is urgently required. In the present study, we selected five conserved antigens, including the secreted factors α-hemolysin (Hla), staphylococcal enterotoxin B (SEB) and the three surface proteins staphylococcal protein A (SpA), iron surface determinant B N2 domain (IsdB-N2) and manganese transport protein C (MntC). They were all well-characterized virulence factor of S. aureus and developed a recombinant five-antigen S. aureus vaccine (rFSAV), rFSAV provided consistent protection in S. aureus lethal sepsis and pneumonia mouse models, and it showed broad immune protection when challenged with a panel of epidemiologically relevant S. aureus strains. Meanwhile, rFSAV immunized mice were able to induce comprehensive cellular and humoral immune responses to reduce bacterial loads, inflammatory cytokine expression, inflammatory cell infiltration and decrease pathology after challenge with a sub-lethal dose of S. aureus. Moreover, the importance of specific antibodies in protection was demonstrated by antibody function tests in vitro and in vivo. Altogether, our data demonstrate that rFSAV is a potentially promising vaccine candidate for defensing against S. aureus infection.

scholarly journals Protective Role of d-Amino Acid Oxidase against Staphylococcus aureus Infection

2012 ◽  
Vol 80 (4) ◽  
pp. 1546-1553 ◽  
Author(s):  
Hideaki Nakamura ◽  
Jun Fang ◽  
Hiroshi Maeda
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Bactericidal Activity ◽  
Hypochlorous Acid ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Content Type

ABSTRACTd-Amino acid oxidase (DAO) is a hydrogen peroxide-generating enzyme that uses ad-amino acid as a substrate. We hypothesized that DAO may protect against bacterial infection, because hydrogen peroxide is one of the most important molecules in the antibacterial defense systems in mammals. We show here that DAO suppressed the growth ofStaphylococcus aureusin a manner that depended on the concentration of DAO andd-amino acidin vitro. Addition of catalase abolished the bacteriostatic activity of DAO. Although DAO plusd-Ala showed less bactericidal activity, addition of myeloperoxidase (MPO) greatly enhanced the bactericidal activity of DAO. Furthermore, DAO was able to utilize bacterial lysate, which containsd-Ala derived from peptidoglycan; this could produce hydrogen peroxide with, in the presence of myeloperoxidase, formation of hypochlorous acid. This concerted reaction of DAO and MPO led to the bactericidal action.In vivoexperiments showed that DAO−/−(mutant) mice were more susceptible toS. aureusinfection than were DAO+/+(wild-type) mice. These results suggest that DAO, together with myeloperoxidase, may play an important role in antibacterial systems in mammals.

scholarly journals Impact of Bicarbonate on PBP2a Production, Maturation, and Functionality in Methicillin-Resistant Staphylococcus aureus (MRSA)

2021 ◽  
Author(s):  
Selvi C. Ersoy ◽  
Henry F. Chambers ◽  
Richard A. Proctor ◽  
Adriana E. Rosato ◽  
Nagendra N. Mishra ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Ex Vivo ◽  
Carotenoid Content ◽  
Methicillin Resistant ◽  
Genes Encoding ◽  
Regulatory Impact ◽  
Mrsa Strains ◽  
The Impact

Certain methicillin-resistant Staphylococcus aureus (MRSA) strains exhibit β-lactam-susceptibility in vitro, ex vivo and in vivo in the presence of NaHCO3 (NaHCO3-responsive MRSA). Herein, we investigate the impact of NaHCO3 on factors required for PBP2a functionality. Prototype NaHCO3-responsive and -nonresponsive MRSA strains (as defined in vitro) were assessed for the impact of NaHCO3 on: expression of genes involved in PBP2a production-maturation pathways (mecA, blaZ, pbp4, vraSR, prsA, sigB, and floA); membrane PBP2a and PrsA protein content; and membrane carotenoid content. Following NaHCO3 exposure in NaHCO3-responsive (vs - nonresponsive) MRSA, there was significantly reduced expression of: i) mecA and blaZ; ii) the vraSR-prsA gene axis; and iii) pbp4. Carotenoid production was reduced, while floA expression was increased by NaHCO3 exposure in all MRSA strains. This work underscores the distinct regulatory impact of NaHCO3 on a cadre of genes encoding factors required for maintenance of the MRSA phenotype through PBP2a functionality and maturation.

scholarly journals Erianin against Staphylococcus aureus Infection via Inhibiting Sortase A

Toxins ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 385 ◽  
Author(s):  
Ping Ouyang ◽  
Xuewen He ◽  
Zhong-Wei Yuan ◽  
Zhong-Qiong Yin ◽  
Hualin Fu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Hydrophobic Interactions ◽  
Multidrug Resistant ◽  
Vital Role ◽  
Surface Proteins ◽  
Dynamics Simulation ◽  
Sortase A

With continuous emergence and widespread of multidrug-resistant Staphylococcus aureus infections, common antibiotics have become ineffective in treating these infections in the clinical setting. Anti-virulence strategies could be novel, effective therapeutic strategies against drug-resistant bacterial infections. Sortase A (srtA), a transpeptidase in gram-positive bacteria, can anchor surface proteins that play a vital role in pathogenesis of these bacteria. SrtA is known as a potential antivirulent drug target to treat bacterial infections. In this study, we found that erianin, a natural bibenzyl compound, could inhibit the activity of srtA in vitro (half maximal inhibitory concentration—IC50 = 20.91 ± 2.31 μg/mL, 65.7 ± 7.2 μM) at subminimum inhibitory concentrations (minimum inhibitory concentrations—MIC = 512 μg/mL against S. aureus). The molecular mechanism underlying the inhibition of srtA by erianin was identified using molecular dynamics simulation: erianin binds to srtA residues Ile182, Val193, Trp194, Arg197, and Ile199, forming a stable bond via hydrophobic interactions. In addition, the activities of S. aureus binding to fibronectin and biofilm formation were inhibited by erianin, when co-culture with S. aureus. In vivo, erianin could improve the survival in mice that infected with S. aureus by tail vein injection. Experimental results showed that erianin is a potential novel therapeutic compound against S. aureus infections via affecting srtA.

scholarly journals Detection, Characterization, and In Vitro and In Vivo Expression of Genes Encoding S-Proteins in Lactobacillus gallinarum Strains Isolated from Chicken Crops

2005 ◽  
Vol 71 (11) ◽  
pp. 6633-6643 ◽  
Author(s):  
Karen E. Hagen ◽  
Le Luo Guan ◽  
Gerald W. Tannock ◽  
Doug R. Korver ◽  
Gwen E. Allison
Keyword(s):  
Broiler Chickens ◽  
Surface Proteins ◽  
Specific Gene ◽  
Published Data ◽  
Bacterial Strains ◽  
S Protein ◽  
Genes Encoding ◽  
S Proteins

ABSTRACT Thirty-eight isolates of Lactobacillus gallinarum cultured from the crops of broiler chickens were screened for the presence of genes encoding S-layer proteins. All of the isolates had two S-protein genes, which were designated Lactobacillus gallinarum S-protein (lgs) genes. One gene in each isolate was either lgsA or lgsB. The Lactobacillus isolates were further characterized by pulsed-field gel electrophoresis of DNA digests, which grouped the isolates into 17 genotypes (strains). The second gene in each of eight representative strains was sequenced and shown to differ among strains (lgsC, lgsD, lgsE, lgsF, lgsG, lgsH, and lgsI). The genome of each strain thus encoded a common S-protein (encoded by either lgsA or lgsB) and a strain-specific S-protein. The extraction of cell surface proteins from cultures of the eight strains showed that each strain produced a single S-protein that was always encoded by the strain-specific lgs gene. Two of the strains were used to inoculate chickens maintained in a protected environment which were Lactobacillus-free prior to inoculation. DNAs and RNAs extracted from the digesta of the chickens were used for PCR and reverse transcription-PCR, respectively, to demonstrate the presence and transcription of lgs genes in vivo. In both cases, only the strain-specific gene was transcribed. Both of the strains adhered to the crop epithelium, consistent with published data predicting that S-proteins of lactobacilli are adhesins. The results of this study provide a basis for the investigation of gene duplication and sequence variation as mechanisms by which bacterial strains of the same species can share the same habitat.

scholarly journals The Fibrinogen- and Fibronectin-Binding Domains of Staphylococcus aureus Fibronectin-Binding Protein A Synergistically Promote Endothelial Invasion and Experimental Endocarditis

2008 ◽  
Vol 76 (8) ◽  
pp. 3824-3831 ◽  
Author(s):  
Lionel Piroth ◽  
Yok-Ai Que ◽  
Eleonora Widmer ◽  
Alexandre Panchaud ◽  
Stéphane Piu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Binding Protein ◽  
Protein A ◽  
Binding Domains ◽  
Fibrinogen Binding ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding

ABSTRACT Staphylococcus aureus experimental endocarditis relies on sequential fibrinogen binding (for valve colonization) and fibronectin binding (for endothelial invasion) conferred by peptidoglycan-attached adhesins. Fibronectin-binding protein A (FnBPA) reconciles these two properties—as well as elastin binding—and promotes experimental endocarditis by itself. Here we attempted to delineate the minimal subdomain of FnBPA responsible for fibrinogen and fibronectin binding, cell invasion, and in vivo endocarditis. A large library of truncated constructs of FnBPA was expressed in Lactococcus lactis and tested in vitro and in animals. A 127-amino-acid subdomain spanning the hinge of the FnBPA fibrinogen-binding and fibronectin-binding regions appeared necessary and sufficient to confer the sum of these properties. Competition with synthetic peptides could not delineate specific fibrinogen- and fibronectin-binding sites, suggesting that dual binding arose from protein folding, irrespective of clearly defined binding domains. Moreover, coexpressing the 127-amino-acid subdomain with remote domains of FnBPA further increased fibrinogen binding by ≥10 times, confirming the importance of domain interactions for binding efficacy. In animals, fibrinogen binding (but not fibronectin binding) was significantly associated with endocarditis induction, whereas both fibrinogen binding and fibronectin binding were associated with disease severity. Moreover, fibrinogen binding also combined with fibronectin binding to synergize the invasion of cultured cell lines significantly, a feature correlating with endocarditis severity. Thus, while fibrinogen binding and fibronectin binding were believed to act sequentially in colonization and invasion, they appeared unexpectedly intertwined in terms of both functional anatomy and pathogenicity (in endocarditis). This unforeseen FnBPA subtlety might bear importance for the development of antiadhesin strategies.

Oxytocin analogues with non-coded amino acid residues in position 8: [8-Neopentylglycine]oxytocin and [8-cycloleucine]oxytocin

1987 ◽  
Vol 52 (9) ◽  
pp. 2317-2325 ◽  
Author(s):  
Jan Hlaváček ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Walter Y. Chan ◽  
Victor J. Hruby
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
The Other ◽  
Amino Acid Residues ◽  
Phase Synthesis ◽  
Other Hand ◽  
Fragment Condensation

[8-Neopentylglycine]oxytocin (II) and [8-cycloleucine]oxytocin (III) were prepared by a combination of solid-phase synthesis and fragment condensation. Both analogues exhibited decreased uterotonic potency in vitro, each being about 15-30% that of oxytocin. Analogue II also displayed similarly decreased uterotonic potency in vivo and galactogogic potency. On the other hand, analogue III exhibited almost the same potency as oxytocin in the uterotonic assay in vivo and in the galactogogic assay.

Synthesis of Fragments of the Vasoactive Intestinal Peptide (VIP) and Analysis of Their Residual Biological Activities

1995 ◽  
Vol 60 (7) ◽  
pp. 1229-1235 ◽  
Author(s):  
Ivana Zoulíková ◽  
Ivan Svoboda ◽  
Jiří Velek ◽  
Václav Kašička ◽  
Jiřina Slaninová ◽  
...  
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Residual Activity ◽  
Detailed Examination ◽  
Amino Acid Residues ◽  
Linear Peptide ◽  
Zone Electrophoresis ◽  
Capillary Zone

The vasoactive intestinal (poly)peptide (VIP) is a linear peptide containing 28 amino acid residues, whose primary structure indicates a low metabolic stability. The following VIP fragments, as potential metabolites, and their analogues were prepared by synthesis on a solid: [His(Dnp)1]VIP(1-10), VIP(11-14), [D-Arg12]VIP(11-14), [Lys(Pac)15,21,Arg20]VIP(15-22), and VIP(23-28). After purification, the peptides were characterized by amino acid analysis, mass spectrometry, RP HPLC, and capillary zone electrophoresis. In some tests, detailed examination of the biological activity of the substances in vivo and in vitro gave evidence of a low, residual activity of some fragments, viz. a depressoric activity in vivo for [His(Dnp)1]VIP(1-10) and a stimulating activity for the release of α-amylase in vitro and in vivo for [Lys(Pac)15,21,Arg20]VIP(15-22) and VIP(23-28).

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