scholarly journals Development of monospecific polyclonal antibodies against hypervirulent Klebsiella pneumoniae

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Darniati Darniati ◽  
Surachmi Setiyaningsih ◽  
Dewi Ratih Agungpriyono ◽  
Ekowati Handharyani

Abstract. Darniati, Setiyaningsih S, Agungpriyono DR, Handharyani E. 2021. Development of monospecific polyclonal antibodies against hypervirulent Klebsiella pneumoniae. Biodiversitas 22: 99-105. The aim of the research was to produce monospecific antibodies against Klebsiella pneumoniae serotype K1 and K2. Klebsiella pneumonia isolates were recovered from pneumonic lungs of Aceh cattle. The bacteria were identified by rpoB (RNA polymerase β subunit) PCR amplification specific for K. pneumoniae. The presence of  capsule cluster gene magA  and k2A  was used to characterize capsular serotype K1 and K2, respectively. Antisera were produced using serial immunization of New Zealand White rabbits with K. pneumoniae serotypes K1 and K2. The presence of antibodies was determined by using immunodiffusion test and purification was performed by immunoaffinity purification method. K. pneumoniae antibodies began to appear on the 14th day after the first injection and progressively intensified after the 1st and 2nd booster. The cross-reactivity between the antigen was eliminated by absorbing the antisera with the opposite antigen and several serotypes of non-K1/K2. After purification, serum protein concentrations were substantially decreased from 58.48 µg/µL and 53.99 µg/µL to 2.38 µg / µL and 3.72 µg / µL for K1 and K2, respectively). The SDS-PAGE analysis showed two bands with molecular weight at 54 kDa and 25 kDa representing the heavy and light chains of immunoglobulin G, respectively. Purified polyclonal antiseras against K. pneumoniae serotypes K1 and K2 showed high affinity and specificity for homologous antigens in immunodiffusion and direct agglutination tests, and immunohistochemical staining.

2021 ◽  
Vol 2 (1) ◽  
pp. 01-05
Author(s):  
Krishna Nallagangula

Cirrhosis of liver is an end stage of chronic liver insults from varied etiologies which leads to impaired liver functions. Proteins expressed from liver and enters into circulation reflects degree of liver dysfunction. Serpins (Serine protease inhibitors) are class of plasma proteins expressed from liver; SERPINA4/Kallistatin is a multifunctional serpin clade A protein expressed from liver and concentration in serum is the reflection of extent of liver dysfunction. The present study aimed to compare cross reactivity of serpins for polyclonal and monospecific antibodies in both cirrhotic liver and healthy subjects. Blood samples were collected from 20 subjects (10 cirrhotic liver, 10 healthy) from R. L. Jalappa Hospital and Research Centre, Kolar, Karnataka, India. Separation of proteins was carried out by SDS-PAGE. Cross reactivity study was analyzed using western blot. Proteins present in cirrhotic liver and healthy subject’s serum were separated by SDS PAGE. There was no band detection on both (cirrhotic liver and healthy) PVDF (polyvinylidene diflouride) membranes with polyclonal antibodies. However, a significant band was observed with protein of interest in healthy PVDF membrane with monospecific antibodies. There was no band in cirrhotic liver PVDF membrane even with monospecific antibodies. Comparative cross reactivity analysis of serpins in quantification of SERPINA4/Kallistatin in the present study demonstrated that there will not be any immunological cross reactivity between serpins and SERPINA4/Kallistatin due to the absence of identical epitope in cirrhotic liver and healthy subjects.


Author(s):  
Yanang Wang ◽  
Hanna Fotina

The aim of this study was to prepare B-group aflatoxins(BGAFs) antibody with strong specificity and good eurytopicity. According to the molecular structure and active site of aflatoxin B1 (AFB1), the BGAFs artificial antigen AFB1-BSA was prepared by 6 methods such as oxime active ester(OAE),methylation of ammonia(MOA),mixed anhydride(MA),semi acetal(SA),epoxide(EP) and enol ether derivative(EED) and identified by UV and SDS-PAGE. Polyclonal antibodies against AFB1(AFB1 pAb) were prepared by immunizing New Zealand rabbits with AFB1-BSA, and the titers of AFB1 pAb was detected by indirect ELISA, the sensitivity of AFB1 pAb was analyzed by indirect competitive ELISA(icELISA) and the specificity and eurytopicity of AFB1 pAb was analyzed by cross-reactivity(CR) test. The results showed that AFB1-BSA was synthesized successfully and the best one was OAE method among 6 synthesis methods of BGAFs artificial antigen and its conjugation ratio of AFB1 to BSA was about 8.46∶1. The immune efficacy of OAE method was the best, its AFB1 pAb had high titers of 1∶(1.28×104) by indirect ELISA, a good sensitivity with the 50% inhibition concentration(IC50) of 10.32 μg/L to AFB1 by icELISA and a high CR to AFB2 of 75.21%, AFG1 of 44.13%, AFG2 of 14.72%, AFM1 of 16.36% and AFM2 of 1.44%, respectively. In this study, AFB1 pAbs with high titer, sensitivity, specificity and eurytopicity were prepared, which laid a matter and technical foundation for the establishment of BGAFs immunoassay.


2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Gyeong-Im Shin ◽  
Sun Young Moon ◽  
Song Yi Jeong ◽  
Myung Geun Ji ◽  
Joon-Yung Cha ◽  
...  

AbstractTARGET OF RAPAMYCIN (TOR), a member of the phosphatidylinositol 3-kinase-related family of protein kinases, is encoded by a single, large gene and is evolutionarily conserved in all eukaryotes. TOR plays a role as a master regulator that integrates nutrient, energy, and stress signaling to orchestrate development. TOR was first identified in yeast mutant screens, as its mutants conferred resistance to rapamycin, an antibiotic with immunosuppressive and anticancer activities. In Arabidopsis thaliana, the loss-of-function tor mutant displays embryo lethality, but the precise mechanisms of TOR function are still unknown. Moreover, a lack of reliable molecular and biochemical assay tools limits our ability to explore TOR functions in plants. Here, we produced a polyclonal α-TOR antibody using two truncated variants of TOR (1–200 and 1113–1304 amino acids) as antigens because recombinant full-length TOR is challenging to express in Escherichia coli. Recombinant His-TOR1−200 and His-TOR1113−1304 proteins were individually expressed in E. coli, and a mixture of proteins (at a 1:1 ratio) was used for immunizing rabbits. Antiserum was purified by an antigen-specific purification method, and the purified polyclonal α-TOR antibody successfully detected endogenous TOR proteins in wild-type Arabidopsis and TOR orthologous in major crop plants, including tomato, maize, and alfalfa. Moreover, our α-TOR antibody is useful for coimmunoprecipitation assays. In summary, we generated a polyclonal α-TOR antibody that detects endogenous TOR in various plant species. Our antibody could be used in future studies to determine the precise molecular mechanisms of TOR, which has largely unknown multifunctional roles in plants.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Abhishek Singh ◽  
Vivek Sahajpal ◽  
Mukesh Thakur ◽  
Lalit Kumar Sharma ◽  
Kailash Chandra ◽  
...  

Abstract Objectives Human identification systems based on STRs are widely used in human population genetics and forensic analysis. This study aimed to validate the cross-reactivity of three widely known human-specific STR identification systems i.e. GlobalFiler™ PCR Amplification Kit, Investigator 24plex QS Kit, and PowerPlex® Fusion 6C in chimpanzee. Results The present study revealed the successful amplification of 18 loci using GlobalFiler™ PCR Amplification Kit, 18 loci using Investigator 24plex QS Kit, and 20 loci using PowerPlex® Fusion 6C system. The marker Amelogenin (AMEL) showed differential allele size between male and female revealing the gender identity of chimpanzees and thus validates their application concerning forensic examination, population estimation, and genetic analysis.


Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 254
Author(s):  
Shelby S. Szteiter ◽  
Ilse N. Diego ◽  
Jonathan Ortegon ◽  
Eliana Salinas ◽  
Abcde Cirilo ◽  
...  

Snake envenomation can result in hemorrhage, local necrosis, swelling, and if not treated properly can lead to adverse systemic effects such as coagulopathy, nephrotoxicity, neurotoxicity, and cardiotoxicity, which can result in death. As such, snake venom metalloproteinases (SVMPs) and disintegrins are two toxic components that contribute to hemorrhage and interfere with the hemostatic system. Administration of a commercial antivenom is the common antidote to treat snake envenomation, but the high-cost, lack of efficacy, side effects, and limited availability, necessitates the development of new strategies and approaches for therapeutic treatments. Herein, we describe the neutralization ability of anti-disintegrin polyclonal antibody on the activities of isolated disintegrins, P-II/P-III SVMPs, and crude venoms. Our results show disintegrin activity on platelet aggregation in whole blood and the migration of the SK-Mel-28 cells that can be neutralized with anti-disintegrin polyclonal antibody. We characterized a SVMP and found that anti-disintegrin was also able to inhibit its activity in an in vitro proteolytic assay. Moreover, we found that anti-disintegrin could neutralize the proteolytic and hemorrhagic activities from crude Crotalus atrox venom. Our results suggest that anti-disintegrin polyclonal antibodies have the potential for a targeted approach to neutralize SVMPs in the treatment of snakebite envenomations.


2017 ◽  
Vol 30 (6) ◽  
pp. 496 ◽  
Author(s):  
Aida Pereira ◽  
Tiago Petrucci ◽  
Maria João Simões

The hypervirulent K1 serotype Klebsiella pneumoniae is responsible for a new invasive syndrome, typically associated to hepatic abscesses with extra-hepatic complications. Initially described in Taiwan, it has significantly spread to several Asian countries and more recently to Europe and North America, thus constituting an emerging and global problem. The authors describe a case report of a 64-years-old portuguese caucasian woman without any previous diseases or epidemiological risk factors such as trips or contact with Asian products or population, diagnosed with a pyogenic liver abscess with pleural effusion caused by this hyper-virulent strain. A successful clinical cure was achieved after the etiological identification and treatment with antimicrobial therapy combined with catheter drainage. This is the first identification of hypervirulent Klebsiella pneumonia ST 23 clone in Portugal in the context of an invasive syndrome.


2005 ◽  
Vol 288 (1) ◽  
pp. C141-C147 ◽  
Author(s):  
Yu-Hua Zhang ◽  
Diego Alvarez de la Rosa ◽  
Cecilia M. Canessa ◽  
John P. Hayslett

The purpose of this study was to determine whether there is a correlation between phosphorylation and activity of the epithelial sodium channel (ENaC). The three subunits that form the channel were immunoprecipitated from A6 cells by using specific polyclonal antibodies after labeling cells with 35S or 32P. When immune complexes were resolved on SDS-PAGE, the α-subunit migrated at 85 and 65 kDa, the β-subunit at 115 and 100 kDa, and the γ-subunit at 90 kDa. In the resting state all three subunits were phosphorylated. The α-subunit was phosphorylated only in the 65-kDa band, suggesting that the posttranslational modification that gives rise to the rapidly migrating form of α is a requirement for phosphorylation. Stimulation with 100 nM insulin for 30 min increased phosphorylation of α-, β-, and γ-subunits approximately twofold. Exposure to 1 μM aldosterone for 16 h increased protein abundance and phosphorylation proportionately in the three subunits. When insulin was applied to cells pretreated with aldosterone, phosphorylation was also increased approximately twofold, but the total amount of phosphorylated substrate was larger than in control conditions because of the action of aldosterone. This result might explain the synergistic increase in sodium transport under the same conditions. The protein kinase C inhibitor chelerythrine abolished insulin effects and decreased sodium transport and subunit phosphorylation. Together, our findings suggest that ENaC activity is controlled by subunit phosphorylation in cells that endogenously express the channel and the machinery for hormonal stimulation of sodium transport.


1993 ◽  
Vol 291 (3) ◽  
pp. 765-771 ◽  
Author(s):  
P R Williamson ◽  
M A Huber ◽  
J E Bennett

Two isoenzymes of maltase (EC 3.2.1.20) were purified to homogeneity from Candida albicans. Isoenzymes I and II were found to have apparent molecular masses of 63 and 66 kDa on SDS/PAGE with isoelectric points of 5.0 and 4.6 respectively. Both isoenzymes resembled each other in similar N-terminal sequence, specificity for the alpha(1-−>4) glycosidic linkage and immune cross-reactivity on Western blots using a maltase II antigen-purified rabbit antibody. Maltase was induced by growth on sucrose whereas beta-fructofuranosidase activity could not be detected under similar conditions. Maltase I and II were shown to be unglycosylated enzymes by neutral sugar assay, and more than 90% of alpha-glucosidase activity was recoverable from spheroplasts. These data, in combination with other results from this laboratory [Geber, Williamson, Rex, Sweeney and Bennett (1992) J. Bacteriol. 174, 6992-6996] showing lack of a plausible leader sequence in genomic or mRNA transcripts, suggest an intracellular localization of the enzyme. To establish further the mechanism of sucrose assimilation by maltase, the existence of a sucrose-inducible H+/sucrose syn-transporter was demonstrated by (1) the kinetics of sucrose-induced [14C]sucrose uptake, (2) recovery of intact [14C]sucrose from ground cells by t.l.c. and (3) transport of 0.83 mol of H+/mol of [14C]sucrose. In total, the above is consistent with a mechanism whereby sucrose is transported into C. albicans to be hydrolysed by an intracellular maltase.


2018 ◽  
Vol 12 (06) ◽  
pp. 422-428 ◽  
Author(s):  
Hadir ElMahallawy ◽  
Mai Mahmoud Zafer ◽  
Mohamed Al-Agamy ◽  
Magdy Aly Amin ◽  
Mai Muhammed Mersal ◽  
...  

Introduction: The worldwide dissemination of the acquired carbapenemases in Gram-negative bacteria is a strongly expressed demand for the emergence of post antibiotic era. The aim of this study was to test the production of carbapenemase by Klebsiella pneumoniae strains isolated from hospitalized cancer patients and to investigate the genetic relationship of carbapenemase producing carbapenem resistant K. pneumoniae using multilocus sequence typing (MLST). Methodology: Antibiotic susceptibility testing and phenotypic testing for extended spectrum b-lactamases (ESBL) and carbapenemases production were performed. PCR amplification of ESBL and carbapenemase genes was performed. MLST was done to detect the genetic relatedness of the isolates. Results: Our data showed all strains were sensitive to colistin. Carba NP test was positive in thirty-one carbapenem resistant K. pneumoniae isolates and 26 out of 34 K. pneumoniae isolates were metallo-beta-lactamases (MBL) positive. All carbapenemase-positive isolates were ESBL CTX-M-1-like positive. blaOXA-48 gene was detected in 25 isolates (80.65%) and 21 isolates (67.75%) produced blaNDM-1 like enzyme. VIM and KPC genes were not identified in this study. Association of blaOXA-48 like and blaNDM-1 like was found in 15 (48.39%) isolates, while the coproduction of OXA-48-like and IMP-1 was revealed in only one K. pneumoniae isolate. MLST revealed ten distinct sequence types (STs). Conclusion: Here we have documented the coexistence of NDM-type and OXA-48-like, and the coproduction of OXA-48-like and IMP in carbapenem resistant K. pneumoniae in patients with cancer. The dominant clone of the OXA-48-like-producing K. pneumoniae isolates from Egypt was ST101 epidemic clone belonging to clonal complex 101, an association that has been reported worldwide. The second most frequent ST was ST383.ST11 was assigned to OXA-48-producing K. pneumoniae.


2021 ◽  
Vol 5 (1) ◽  
pp. 001-007
Author(s):  
Ostojic Maja ◽  
Hubana Mahir ◽  
Cvetnić Marija ◽  
Benić Miroslav ◽  
Cvetnić Zeljko

Background: Klebsiella pneumoniae is a bacterial species that often causes infections in humans. Infections occur most frequently in hospitalised or immunocompromised patients and are treated with antimicrobials. In recent decades, K. pneumoniae has developed significant resistance to many antimicrobials. Objective: The main goal of this study was to determine the frequency of resistance of isolated K. pneumoniae strains from urine samples of hospital patients and outpatients, and to find evidence of ESBL strains and their resistance to certain antibiotics. Methods: During the study period, Klebsiella pneumonia was isolated from the urine samples of 430 patients. The procedure for processing of urine samples, identification, susceptibility toward antimicrobials and evidence of ESBL strains were carried out according to the recommended standards. Results: Of the total K. pneumoniae isolates, 153 (35.6%) were isolated from hospital patients and 277 (64.4%) from outpatients. Strains isolated from hospital patients were resistant to each tested antibiotic. ESBL strains were detected in 169 (39.30%) samples, 92 (60.13%) from hospital patients and 77 (27.8%) from outpatients. Conclusion: Strains of K. pneumoniae isolated from the urine of hospital patients and outpatients have developed significant resistance against all tested antibiotic substances. A higher occurrence of ESBL strains was observed in hospital patients than in outpatients. ESBL strains were resistant to all penicillins and almost all cephalosporins. Highly effective antimicrobials were amikacin, colistine, carbapenem and fosfomycin. The best therapeutic results were achieved when patients were treated with fosfomycin and imipenem.


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