scholarly journals Comparison of Antibody Repertoires against Staphylococcus aureus in Healthy Individuals and in Acutely Infected Patients

2005 ◽  
Vol 12 (3) ◽  
pp. 387-398 ◽  
Author(s):  
Agnieszka Dryla ◽  
Sonja Prustomersky ◽  
Dieter Gelbmann ◽  
Markus Hanner ◽  
Edith Bettinger ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
High Titer ◽  
In Vitro Assays ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immune Recognition ◽  
Healthy Individuals ◽  
Promising Alternative ◽  
Immune Correlates ◽  
Wide Range ◽  
Antibody Repertoires

ABSTRACT The management of staphylococcal diseases is increasingly difficult with present medical approaches. Preventive and therapeutic vaccination is considered to be a promising alternative; however, little is known about immune correlates of protection and disease susceptibility. To better understand the immune recognition of Staphylococcus aureus by the human host, we studied the antistaphylococcal humoral responses in healthy people in comparison to those of patients with invasive diseases. In a series of enzyme-linked immunosorbent assay analyses performed using 19 recombinant staphylococcal cell surface and secreted proteins, we measured a wide range of antibody levels, finding a pronounced heterogeneity among individuals in both donor groups. The analysis revealed marked differences in the antibody repertoires of healthy individuals with or without S. aureus carriage, as well as in those of patients in the acute phase of infection. Most importantly, we identified antigenic proteins for which specific antibodies were missing or underrepresented in infected patients. In contrast to the well-described transient nature of disease-induced antistaphylococcal immune response, it was demonstrated that high-titer antistaphylococcal antibodies are stable for years in healthy individuals. In addition, we provide evidence obtained on the basis of opsonophagocytic and neutralizing activity in vitro assays that circulating antistaphylococcal serum antibodies in healthy donors are functional. In light of these data we suggest that proper serological analysis comparing the preexisting antibody repertoires of hospitalized patients with different outcomes for nosocomial staphylococcal infections could be extremely useful for the evaluation of candidate vaccine antigens in addition to protection data generated with animal models.

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 Synthesis, Characterization and Estimation the Biological Activity of New Mesomorphic Heterocyclic Compounds

2020 ◽  
Vol 10 (01) ◽  
pp. 106-113
Author(s):  
Hussain A. Hamza ◽  
Nasreen R. Jber
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
High Titer ◽  
Resistant Bacteria ◽  
Skin Infections ◽  
Promising Alternative ◽  
Methicillin Resistant ◽  
Phage Cocktail

Methicillin-resistant Staphylococcus aureus (MRSA) is a S. aureus that resistant to β-lactam antibiotics (e.g., Cefoxitin and Oxacillin). MRSA has a tremendous capacity to develop resistance to other classes of antibiotics and forming a real threat to patients. The process of exploring a new tactic of non-antibiotic treatments has become an urgent need. A bacteriophage is one of the possible treatments that strongly suggested. Bacteriophages are viruses that infect bacteria as a natural host with a bactericidal capability against multidrug-resistant bacteria that do not respond to conventional antibiotics. The current study investigates the lytic efficacy of phage-cocktail in vitro, specifically against S. aureus isolated from skin infections and find out the possible association of phage-antibiotic resistance. A total of 43 isolates of Methicillin-resistant staphylococcus aureus were isolated from skin infections. The isolates are distributed as (10 isolates of burn, 4 isolates of diabetic foot ulcer, 7 isolates of surgical wounds, 3 isolates of pressure ulcer, and 19 of skin and soft tissue infection). The isolates exhibited variant antibiotic susceptibility against 12 antibiotics (Cefoxitin FOX, Vancomycin VAN, Oxacillin OX, Rifampin RA, Chloramphenicol C, Nitrofurantoin F, Clindamycin DA, Azithromycin AZM, Amikacin AK, Trimethoprim-sulfamethoxazole SXT, Ciprofloxacin CIP, and Gentamicin CN). A bacteriophage cocktail was isolated using a phage-enrichment technique, high titer phage lysate (5*109 pfu/ml) was obtained and investigated against 43 MRSA isolates. The phage-cocktail showed high specificity to S. aureus but variable susceptibility to 43 MRSA isolates. It was observed that there was no association (p greater than 0.05) between phage and antibiotic resistance of (FOX, OX, VAN, RA, C, F, and DA) where the significant association was observed (p less than 0.05) with (AZM, AK, SXT, CIP, and CN). Significantly, the more antibiotic-resistant isolates exhibited more sensitivity to phage-cocktail, which represents a promising alternative to antibiotics that do not affect with increasing antibiotic resistance.

scholarly journals Combined Use of Bacteriophage K and a Novel Bacteriophage To Reduce Staphylococcus aureus Biofilm Formation

2014 ◽  
Vol 80 (21) ◽  
pp. 6694-6703 ◽  
Author(s):  
D. R. Alves ◽  
A. Gaudion ◽  
J. E. Bean ◽  
P. Perez Esteban ◽  
T. C. Arnot ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
High Titer ◽  
Broad Host Range ◽  
Bacterial Host ◽  
Content Type ◽  
Double Stranded Dna ◽  
Patient Morbidity ◽  
Combined Use ◽  
Wide Range ◽  
Large Repertoire

ABSTRACTBiofilms are major causes of impairment of wound healing and patient morbidity. One of the most common and aggressive wound pathogens isStaphylococcus aureus, displaying a large repertoire of virulence factors and commonly reduced susceptibility to antibiotics, such as the spread of methicillin-resistantS. aureus(MRSA). Bacteriophages are obligate parasites of bacteria. They multiply intracellularly and lyse their bacterial host, releasing their progeny. We isolated a novel phage, DRA88, which has a broad host range amongS. aureusbacteria. Morphologically, the phage belongs to theMyoviridaefamily and comprises a large double-stranded DNA (dsDNA) genome of 141,907 bp. DRA88 was mixed with phage K to produce a high-titer mixture that showed strong lytic activity against a wide range ofS. aureusisolates, including representatives of the major international MRSA clones and coagulase-negativeStaphylococcus. Its efficacy was assessed both in planktonic cultures and when treating established biofilms produced by three different biofilm-producingS. aureusisolates. A significant reduction of biofilm biomass over 48 h of treatment was recorded in all cases. The phage mixture may form the basis of an effective treatment for infections caused byS. aureusbiofilms.

scholarly journals Histidine-Rich Protein II: a Novel Approach to Malaria Drug Sensitivity Testing

2002 ◽  
Vol 46 (6) ◽  
pp. 1658-1664 ◽  
Author(s):  
Harald Noedl ◽  
Walther H. Wernsdorfer ◽  
Robert Scott Miller ◽  
Chansuda Wongsrichanalai
Keyword(s):  
Drug Sensitivity ◽  
Drug Susceptibility ◽  
New Drugs ◽  
World Health ◽  
In Vitro Assays ◽  
Enzyme Linked Immunosorbent Assay ◽  
Technical Equipment ◽  
Sensitivity Testing ◽  
Wide Range

ABSTRACT The production of histidine-rich protein II (HRP2), a histidine- and alanine-rich protein produced by Plasmodium falciparum, is closely associated with the development and proliferation of the parasite and therefore is perfectly suited to reflect growth inhibition as a measure of drug susceptibility. It was the aim of the present study to develop a malaria drug sensitivity assay based on the measurement of HRP2 in a simple enzyme-linked immunosorbent assay (ELISA). The new test proved to be as reliable as traditional in vitro assays, while it was considerably easier to establish and perform. Parasites are incubated at an initial level of parasitemia of 0.01 to 0.1% on microculture plates predosed with ascending concentrations of antimalarial drugs. After incubation for 48 to 72 h, the samples are freeze-thawed and transferred to ELISA plates. The complete ELISA takes about 2.5 h to perform, may be carried out with commercially available test kits, and requires relatively little technical equipment. In correlation analysis, the results closely paralleled those obtained by the isotopic assay (R = 0.892; P < 0.0001) and World Health Organization schizont maturation tests (R = 0.959; P < 0.0001). The novel HRP2 drug susceptibility assay proved to be very sensitive, simple to establish, and highly reproducible. It can be used for a wide range of applications, from epidemiological studies to the screening of new drugs, and may have the potential to replace traditional in vitro techniques. Standard operating procedures, updated information, and analytical software are available from http://malaria.farch.net .

scholarly journals High Titer of Antibody Against Pneumococcal IgA1 Protease in Healthy Individuals

2020 ◽  
Vol 14 (1) ◽  
pp. 229-233
Author(s):  
Mina Gholami ◽  
Davoud Afshar ◽  
Mozhgan Kheirandish ◽  
Farzaneh Rafiee ◽  
Reza Ranjbar ◽  
...  
Keyword(s):  
High Titer ◽  
Age Groups ◽  
Restriction Enzymes ◽  
Enzyme Linked Immunosorbent Assay ◽  
P Value ◽  
Protease Gene ◽  
Healthy Individuals ◽  
Healthy Humans ◽  
Iga1 Protease ◽  
Antibody Titers

Background and Objectives: Considering rising antibiotic resistance in various strains of Streptococcus pneumoniae, there is a need to find new immunogenic candidates for developing pneumococcal vaccines. Immunoglobulin A1 (IgA1) protease is one of the virulence factors playing an important role in the pathogenesis of S. pneumoniae infections. In the present study, we aimed to evaluate the titer of antibody against pneumococcal recombinant IgA1 protease in the serum of healthy humans. Materials and Methods: A part of the IgA1 protease gene (705 bp) from S. pneumonia ATCC 49619 was amplified by PCR and then digested using restriction enzymes and ligated by the pET28a expression vector. The recombinant protein was expressed in E. coli BL21 strain. Affinity chromatography was used to purify the protein. The titer of antibody against the recombinant protease was determined in healthy individuals in three age groups of <2, 2-40, and > 40 years using indirect Enzyme-Linked Immunosorbent Assay (ELISA). Results: The expression and purification of the IgA1 recombinant protease were successful. The concentration of the purified protein was determined as 1.013 mg/ml using the NanoDrop method. The titer of anti-recombinant IgA1 protease antibody (20, 40, 80 and 160) showed a significant correlation with age (p-value<0.05). According to our results, the antibody titer was desirable, especially in individuals over two years old. Conclusion: In the present study, desirable antibody titers against the pneumococcal recombinant IgA1 protease were seen in the three groups’ serum of healthy individuals. However, a significant correlation was not totally observed among groups.

Pursuit of the Abscopal Effect

2020 ◽  
Vol 04 (04) ◽  
pp. 369-372
Author(s):  
Paul B. Romesser ◽  
Christopher H. Crane
Keyword(s):  
Tumor Immunology ◽  
Antitumor Immunity ◽  
Clinical Success ◽  
Immune Recognition ◽  
Immune Modulators ◽  
Cancer Subtypes ◽  
The Past ◽  
Tumor Irradiation ◽  
Wide Range ◽  
Tumor Recognition

AbstractEvasion of immune recognition is a hallmark of cancer that facilitates tumorigenesis, maintenance, and progression. Systemic immune activation can incite tumor recognition and stimulate potent antitumor responses. While the concept of antitumor immunity is not new, there is renewed interest in tumor immunology given the clinical success of immune modulators in a wide range of cancer subtypes over the past decade. One particularly interesting, yet exceedingly rare phenomenon, is the abscopal response, characterized by a potent systemic antitumor response following localized tumor irradiation presumably attributed to reactivation of antitumor immunity.

First Detection of Tobacco Mosaic Virus in Tobacco Fields in Northern Lebanon

2020 ◽  
Vol 20 ◽  
Author(s):  
Rami Obeid ◽  
Elias Wehbe ◽  
Mohamad Rima ◽  
Mohammad Kabara ◽  
Romeo Al Bersaoui ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Viral Genome ◽  
Virus Genome ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Family ◽  
Crop Fields ◽  
Wide Range ◽  
Almost All ◽  
Das Elisa

Background: Tobacco mosaic virus (TMV) is the most known virus in the plant mosaic virus family and is able to infect a wide range of crops, in particularly tobacco, causing a production loss. Objectives: Herein, and for the first time in Lebanon, we investigated the presence of TMV infection in crops by analyzing 88 samples of tobacco, tomato, cucumber and pepper collected from different regions in North Lebanon. Methods: Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), revealed a potential TMV infection of four tobacco samples out of 88 crops samples collected. However, no tomato, cucumber and pepper samples were infected. The TMV+ tobacco samples were then extensively analyzed by RT-PCR to detect viral RNA using different primers covering all the viral genome. Results and Discussion: PCR results confirmed those of DAS-ELISA showing TMV infection of four tobacco samples collected from three crop fields of North Lebanon. In only one of four TMV+ samples, we were able to amplify almost all the regions of viral genome, suggesting possible mutations in the virus genome or an infection with a new, not yet identified, TMV strain. Conclusion: Our study is the first in Lebanon revealing TMV infection in crop fields, and highlighting the danger that may affect the future of agriculture.

scholarly journals Hospital-Based Donor Recruitment and Predonation Serologic Testing for COVID-19 Convalescent Plasma

2021 ◽  
Author(s):  
Joanna Balcerek ◽  
Evelin Trejo ◽  
Kendall Levine ◽  
Paul Couey ◽  
Zoe V Kornberg ◽  
...  
Keyword(s):  
Blood Donation ◽  
High Titer ◽  
Igg Antibodies ◽  
Serologic Testing ◽  
Wide Range ◽  
The Us ◽  
Polymerase Chain ◽  
Igg Level ◽  
Donor Recruitment ◽  
Selection Of

Abstract Objectives Serologic testing for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in potential donors of coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) may not be performed until after blood donation. A hospital-based recruitment program for CCP may be an efficient way to identify potential donors prospectively Methods Patients who recovered from known or suspected COVID-19 were identified and recruited through medical record searches and public appeals in March and April 2020. Participants were screened with a modified donor history questionnaire and, if eligible, were asked for consent and tested for SARS-CoV-2 antibodies (IgG and IgM). Participants positive for SARS-CoV-2 IgG were referred for CCP collection. Results Of 179 patients screened, 128 completed serologic testing and 89 were referred for CCP donation. IgG antibodies to SARS-CoV-2 were detected in 23 of 51 participants with suspected COVID-19 and 66 of 77 participants with self-reported COVID-19 confirmed by polymerase chain reaction (PCR). The anti–SARS-CoV-2 IgG level met the US Food and Drug Administration criteria for “high-titer” CCP in 39% of participants confirmed by PCR, as measured by the Ortho VITROS IgG assay. A wide range of SARS-CoV-2 IgG levels were observed. Conclusions A hospital-based CCP donor recruitment program can prospectively identify potential CCP donors. Variability in SARS-CoV-2 IgG levels has implications for the selection of CCP units for transfusion.

scholarly journals Trans-Cinnamaldehyde Exhibits Synergy with Conventional Antibiotic against Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 22 (5) ◽  
pp. 2752
Author(s):  
Shu Wang ◽  
Ok-Hwa Kang ◽  
Dong-Yeul Kwon
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Synergistic Effects ◽  
Regulatory Gene ◽  
Western Blot Assay ◽  
Methicillin Resistant ◽  
Wide Range ◽  
Kill Curve ◽  
Conventional Antibiotics ◽  
Time Kill

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide and has acquired multiple resistance to a wide range of antibiotics. Hence, there is a pressing need to explore novel strategies to overcome the increase in antimicrobial resistance. The present study aims to investigate the efficacy and mechanism of plant-derived antimicrobials, trans-cinnamaldehyde (TCA) in decreasing MRSA’s resistance to eight conventional antibiotics. A checkerboard dilution test and time–kill curve assay are used to determine the synergistic effects of TCA combined with the antibiotics. The results indicated that TCA increased the antibacterial activity of the antibiotics by 2-16-fold. To study the mechanism of the synergism, we analyzed the mecA transcription gene and the penicillin-binding protein 2a level of MRSA treated with TCA by quantitative RT-PCR or Western blot assay. The gene transcription and the protein level were significantly inhibited. Additionally, it was verified that TCA can significantly inhibit the biofilm, which is highly resistant to antibiotics. The expression of the biofilm regulatory gene hld of MRSA after TCA treatment was also significantly downregulated. These findings suggest that TCA maybe is an exceptionally potent modulator of antibiotics.

scholarly journals POS0169 FETUIN-A AS A MARKER OF OSTEOPOROSIS AND OSTEOPOROTIC FRACTURES IN PATIENTS WITH RHEUMATOID ARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 297.2-297
Author(s):  
Y. Akhverdyan ◽  
E. Papichev ◽  
В. Zavodovsky ◽  
L. Seewordova ◽  
J. Polyakova
Keyword(s):  
Rheumatoid Arthritis ◽  
Blood Serum ◽  
Bone Mineralization ◽  
Expectant Management ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Individuals ◽  
High Concentration ◽  
Mineral Density ◽  
Fetuin A ◽  
Apparently Healthy

Background:The main mechanism of the effect of fetuin-A (FeA) on bone metabolism is its ability to bind calcium and proteins of the TGF-β family. It has been proven that the optimal concentration of TGF-β is necessary for the differentiation of bone tissue, and a high concentration inhibits bone mineralization. Thus, adequate osteogenesis is based on a complex balance between FeA and TGF-β levels. It can be assumed that the determination of the FeA level in the blood of patients with rheumatoid arthritis (RA) will help to optimize the diagnosis and predict the severity of osteoporosis (OP).Objectives:to study the possibility of predicting the development of osteoporosis and osteoporetic fractures in patients with RA, depending on the level of FeA in blood serum.Methods:We examined two groups of patients (52 patients with RA complicated by OP, 58 patients with RA without OP) and 30 apparently healthy individuals. The age of the surveyed ranged from 18 to 72 years, the average duration of the disease was 7.53±0.89 years. In both groups, the FeA level was determined by an indirect enzyme-linked immunosorbent assay using a commercial test. Bone mineral density (BMD) was also measured in both groups (Lunar DPX-NT GE).Results:The average FeA level in the group of RA patients was lower than in the group of conventionally healthy individuals (731.21±109.9 μg/ml and 812.9±76.2 μg/ml, respectively; F=13.34; p=0,0004). The normal FeA level was calculated using the formula M±2σ in the group of apparently healthy individuals and ranged from 653.55 μg/ml to 972.19 μg/ml.A decreased level of FeA was found in 20 patients (86.96%) in the group of patients with OP and only in 3 (13.04%) patients with RA who did not suffer from OP (p<0.001). It can be concluded that patients with RA and a low concentration of FeA in the blood serum have a higher risk of developing OP.In the group of patients with normal FeA level, osteoporetic fractures were observed in 12 (13.79%) patients and were absent in 75 (86.21%) patients (p<0.001). Thus, RA patients with normal serum FeA levels have a lower risk of osteoporetic fractures.We also found a positive significant correlation between the level of FeA and BMD in the femoral neck area. In the group of patients with a reduced FeA level (23 people), the mean BMD values were 0.732±0.022 g/cm2, and in the group of patients with a normal FeA level (87 patients) - 0.890±0.014 g/cm2 (p<0.001, F=27.663). The obtained values are in agreement with the literature data on the effect of the serum FeA concentration on the BMD values.Conclusion:We consider it expedient to determine the serum FeA concentration in patients with RA. At a FeA level of 653.55 μg/ml and below, a higher risk of developing OP and osteoporetic fractures can be predicted. In this case, the patient is shown a standard examination for osteoporosis. At values of 653.55 μg/ml and above, a more expectant management of the patient is allowed. Thus, by determining the serum concentration of FeA, it is possible to implement an integrated approach to the patient and to optimize the schemes for the diagnosis of OP in patients with RA.Disclosure of Interests:None declared

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