Homologous and cross-reacting antibodies in the sera of gnotobiotic rats

1978 ◽  
Vol 24 (4) ◽  
pp. 365-371 ◽  
Author(s):  
Joy C. McLeod ◽  
Edward Balish
Keyword(s):  
Gram Negative Bacteria ◽  
Sprague Dawley ◽  
Gram Positive ◽  
Passive Hemagglutination ◽  
Gram Negative ◽  
E Coli ◽  
Sprague Dawley Rats ◽  
Antibody Titers ◽  
The Relationship ◽  
Reactive Antibody

Sera from Sprague–Dawley rats monoassociated with Clostridium perfringens, C. tertium, C. bifermenlans, Staphylococcus aureus, Escherichia coli, Proteus mirabilis, or Klebsiella pneumoniae for 4 weeks were assayed for homologous and cross-reacting antibodies against antigens on a variety of bacteria. A passive hemagglutination assay, with the antigen(s) consisting of bacteria conjugated to tanned sheep red blood cells, was used to assess antibody titers. Both homologous and cross-reacting antibodies were detected in sera that were collected from the monoassociated animals. Sera from monoassociated rats had agglutinating antibody to genera of bacteria that had not colonized their gastrointestinal tract. Although S. aureus shared some antigens with three species of Clostridium, the relationship was not reciprocal. Sera from rats monoassociated with E. coli, P. mirabilis, or K. pneumoniae had cross-reactive antibody against gram-positive and gram-negative bacteria, but did not have antibodies that could agglutinate H. influenzae type b. Monoassociation with C. perfringens resulted in the production of antibodies against a variety of gram-positive and gram-negative bacteria, but it did not induce cross-reactive antibodies against Corynebacterium diphtheriae, streptococci (groups A, C, and G), or Staphylococcus epidennidis.

Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra
Keyword(s):  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Pyrazole Derivatives ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Curcumin Derivatives ◽  
Structure Activity ◽  
Electron Donating Groups ◽  
Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

scholarly journals Characterization of the β-lactamase specified by the resistance factor R-1818 in Escherichia coli K12 and other Gram-negative bacteria

1971 ◽  
Vol 123 (4) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Dale
Keyword(s):  
Escherichia Coli ◽  
Host Species ◽  
Host Bacterium ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
R Factor ◽  
Relationship Of ◽  
The Relationship

1. The amino acid composition of the β-lactamase from E. coli (R-1818) was determined. 2. The R-1818 β-lactamase is inhibited by formaldehyde, hydroxylamine, sodium azide, iodoacetamide, iodine and sodium chloride. 3. The Km values for benzylpenicillin, ampicillin and oxacillin have been determined by using the R-factor enzyme from different host species. The same values were obtained, irrespective of the host bacterium. 4. The molecular weight of the enzyme was found to be 44600, and was the same for all host species. 5. The relationship of R-1818 and R-GN238 β-lactamases is discussed.

scholarly journals Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles for antibacterial photodynamic therapy

2019 ◽  
Vol 18 (5) ◽  
pp. 1147-1155 ◽  
Author(s):  
Rehan Khan ◽  
Melis Özkan ◽  
Aisan Khaligh ◽  
Dönüs Tuncel
Keyword(s):  
Antibacterial Activity ◽  
Photodynamic Therapy ◽  
Singlet Oxygen ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Water Dispersible ◽  
Gram Positive Bacteria ◽  
High Yields

Water-dispersible glycosylated poly(2,5′-thienylene)porphyrin-based nanoparticles have the ability to generate singlet oxygen in high yields and exhibit light-triggered antibacterial activity against Gram negative bacteria, E. coli as well as Gram positive bacteria, B. subtilis.

scholarly journals Removal efficiency of Gram-positive and Gram-negative bacteria using a natural coagulant during coagulation, flocculation, and sedimentation processes

2019 ◽  
Vol 80 (9) ◽  
pp. 1787-1795 ◽  
Author(s):  
Shazwana Sha'arani ◽  
Siti Noor Fitriah Azizan ◽  
Fazrena Nadia Md Akhir ◽  
Muhamad Ali Muhammad Yuzir ◽  
Nor'azizi Othman ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Food Poisoning ◽  
Bloodstream Infections ◽  
Gram Negative Bacteria ◽  
Membrane Composition ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Jar Test ◽  
Sedimentation Processes

Abstract Staphylococcus sp. as Gram-positive and Escherichia coli as Gram-negative are bacterial pathogens and can cause primary bloodstream infections and food poisoning. Coagulation, flocculation, and sedimentation processes could be a reliable treatment for bacterial removal because suspended, colloidal, and soluble particles can be removed. Chemical coagulants, such as alum, are commonly used. However, these chemical coagulants are not environmentally friendly. This present study evaluated the effectiveness of coagulation, flocculation, and sedimentation processes for removing Staphylococcus sp. and E. coli using diatomite with standard jar test equipment at different pH values. Staphylococcus sp. demonstrated 85.61% and 77.23% significant removal in diatomite and alum, respectively, at pH 5. At pH 7, the removal efficiency decreased to 79.41% and 64.13% for Staphylococcus sp. and E. coli, respectively. At pH 9, there was a decrease in Staphylococcus sp. after adding diatomite or alum compared with that of E. coli. The different removal efficiencies of the Gram-positive and Gram-negative bacteria could be owing to the membrane composition and different structures in the bacteria. This study indicates that diatomite has higher efficiency in removing bacteria at pH 5 and can be considered as a potential coagulant to replace alum for removing bacteria by the coagulation process.

scholarly journals Synthesis and Antibacterial Activity of Chalcones and Pyrimidine-2-ones

2005 ◽  
Vol 2 (2) ◽  
pp. 109-112
Author(s):  
A. K. Parekh ◽  
K. K. Desai
Keyword(s):  
Antibacterial Activity ◽  
Spectral Data ◽  
Elemental Analysis ◽  
Aromatic Aldehydes ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
H Nmr

Some new chalcones have been prepared by Claisen-schmidt condensation of ketone and different aromatic aldehydes. These chalcones on condensation with urea in presence of acid gave Pyrimidine-2-ones. The synthesized compounds have been characterized by elemental analysis, IR and1H NMR spectral data. They have been screened for their antibacterial activity against Gram positive bacteria B. subtillis & S. aureus and Gram negative bacteria E. coli & S. typhi.

scholarly journals Antibacterial Activityof Aqueous And Ethanolic Leaf Extracts Of Vernonia Amygdalina On Selected Species Of Gram Positive And Gram Negative Bacteria

2013 ◽  
Vol 2 (1) ◽  
pp. 147-152 ◽  
Author(s):  
AM Bukar ◽  
MA Isa ◽  
HS Bello ◽  
AS Abdullahi
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Drug ◽  
Gram Negative Bacteria ◽  
Phytochemical Screening ◽  
Vernonia Amygdalina ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Pseudomonas Species

The phytochemical screening and antibacterial activity of ethanolic and Methanolic leaves extract of Vernonia amygdalina against five clinical isolates (Staphylococcus aureus, E. coli, Pseudomonas species, Salmonella species and Proteus species) was determined using standard method of analysis. The results of the antibacterial activity of ethanol, methanol and aqueous extract of leaves of V. amygdalina have diameters ranging between 0.4 to 10mm. The plant extracts from the plants had profound activities against gram-positive than gram negative bacteria. From the above studies, it has clearly indicated that V. amygdalina extract may represent new sources of antibacterial drug, if the phytoactive components are purified and proper dosage are determined for administration. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 147-152 DOI: http://dx.doi.org/10.3126/ije.v2i1.9217

scholarly journals Hybrid Approach for Synthesis and Antimicrobial Activity of Heterocyclic Compounds

2018 ◽  
Vol 77 ◽  
pp. 35-52 ◽  
Author(s):  
Nisheeth C. Desai ◽  
Darshita V. Vaja
Keyword(s):  
Antimicrobial Activity ◽  
Heterocyclic Compounds ◽  
Hybrid Approach ◽  
Spectroscopic Techniques ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Microbial Strains

We have synthesized novel series of N-(1-(2-(1-phenyl-3-(p-tolyl)-1H-pyrazol-4-yl)-5-(pyridin-4-yl)-1,3,4-oxadiazol-3(2H)-yl)ethylidene)arylaniline and their derivatives. The structures of synthesized compounds were well characterized by spectroscopic techniques. Antimicrobial activity of the newly synthesized derivatives was evaluated against gram positive (S. aureus and S. pyogenes), gram negative bacteria (E. coli and P. aeruginosa), and strains of fungi (C. albicans, A. niger and A. clavatus). Among the screened derivatives 5c, 5f, 5i, 5l and 5t demonstrated superior antimicrobial activity against microbial strains.

scholarly journals Biosynthesized Zinc Oxide Nanoparticles Disrupt Established Biofilms of Pathogenic Bacteria

2022 ◽  
Vol 12 (2) ◽  
pp. 710
Author(s):  
Fohad Mabood Husain ◽  
Faizan Abul Qais ◽  
Iqbal Ahmad ◽  
Mohammed Jamal Hakeem ◽  
Mohammad Hassan Baig ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Pathogenic Bacteria ◽  
Oxide Nanoparticles ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Zno Nps ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Global emergence and persistence of the multidrug-resistant microbes have created a new problem for management of diseases associated with infections. The development of antimicrobial resistance is mainly due to the sub-judicious and unprescribed used of antimicrobials both in healthcare and the environment. Biofilms are important due to their role in microbial infections and hence are considered a novel target in discovery of new antibacterial or antibiofilm agents. In this article, zinc oxide nanoparticles (ZnO-NPs) were prepared using extract of Plumbago zeylanica. ZnO-NPs were characterized and then their antibiofilm activity was tested against Gram-positive and Gram-negative bacteria. The ZnO-NPs were polydispersed, and the average size was obtained as 24.62 nm. The presence of many functional groups indicated that phytocompounds of P. zeylanica were responsible for the synthesis, capping, and stabilization of ZnO-NPs. Synthesized NPs inhibited the biofilm formation of E. coli, S. aureus, and P. aeruginosa by 62.80%, 71.57%, and 77.69%, respectively. Likewise, concentration-dependent inhibition of the EPS production was recorded in all test bacteria. Microscopic examination of the biofilms revealed that ZnO-NPs reduced the bacterial colonization on solid support and altered the architecture of the biofilms. ZnO-NPs also remarkably eradicated the preformed biofilms of the test bacteria up to 52.69%, 59.79%, and 67.22% recorded for E. coli, S. aureus, P. aeruginosa, respectively. The findings reveal the ability of green synthesized zinc oxide nanoparticles to inhibit, as well as eradicate, the biofilms of Gram-positive and Gram-negative bacteria.

scholarly journals Conjugative Mobilization of the Rolling-Circle Plasmid pIP823 from Listeria monocytogenes BM4293 among Gram-Positive and Gram-Negative Bacteria

1999 ◽  
Vol 181 (11) ◽  
pp. 3368-3374 ◽  
Author(s):  
Emmanuelle Charpentier ◽  
Guy Gerbaud ◽  
Patrice Courvalin
Keyword(s):  
Listeria Monocytogenes ◽  
Amino Acid Identity ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Rolling Circle ◽  
E Coli ◽  
Rolling Circle Mechanism ◽  
High Level ◽  
High Degree

ABSTRACT We determined the sequence and genetic organization of plasmid pIP823, which contains the dfrD gene; dfrDconfers high-level trimethoprim resistance to Listeria monocytogenes BM4293 by synthesis of dihydrofolate reductase type S2. pIP823 possessed all the features of the pUB110/pC194 plasmid family, whose members replicate by the rolling-circle mechanism. Therep gene encoded a protein identical to RepU, the protein required for initiation of the replication of plasmids pTB913 from a thermophilic Bacillus sp. and pUB110 fromStaphylococcus aureus. The mob gene encoded a protein with a high degree of amino acid identity with the Mob proteins involved in conjugative mobilization and interplasmidic recombination of pTB913 and pUB110. The host range of pIP823 was broad and includedL. monocytogenes, Enterococcus faecalis,S. aureus, Bacillus subtilis, andEscherichia coli. In all these species, pIP823 replicated by generating single-stranded DNA and was stable. Conjugative mobilization of pIP823 was obtained by self-transferable plasmids between L. monocytogenes and E. faecalis, between L. monocytogenes and E. coli, and between strains of E. coli, and by the streptococcal conjugative transposon Tn1545 from L. monocytogenes to E. faecalis, and from L. monocytogenes and E. faecalis to E. coli. These data indicate that the gene flux observed in nature from gram-positive to gram-negative bacteria can occur by conjugative mobilization. Our results suggest that dissemination of trimethoprim resistance in Listeria spp. and acquisition of other antibiotic resistance determinants in this species can be anticipated.

Bacteria rapidly colonize and modulate healing of gastric ulcers in rats

1998 ◽  
Vol 275 (3) ◽  
pp. G425-G432 ◽  
Author(s):  
Susan N. Elliott ◽  
André Buret ◽  
Webb McKnight ◽  
Mark J. S. Miller ◽  
John L. Wallace
Keyword(s):  
Ulcer Healing ◽  
Bacterial Colonization ◽  
Healing Process ◽  
Gastric Ulcers ◽  
Gram Negative Bacteria ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
E Coli ◽  
Beneficial Effects ◽  
The Relationship

The stomach is generally regarded as an environment that is not conducive to bacterial colonization. In this study, we examined the possibility that this changes significantly when an ulcer has formed and that colonization of ulcers interferes with the normal healing process. Gastric ulcers were induced by serosal application of acetic acid. The relationship between ulcer healing and bacterial colonization was examined. The effects of antibiotics, induction of Lactobacilluscolonization, and selective colonization with an antibiotic resistant strain of Escherichia coli on ulcer healing were examined. Within 6–12 h of their induction, gastric ulcers were colonized by a variety of bacteria, with gram-negative bacteria predominating. Suppression of colonization with antibiotics resulted in marked acceleration of healing. Induction of Lactobacillus colonization also accelerated ulcer healing. The beneficial effects of antibiotics were reversed through selective colonization with antibiotic-resistant E. coli. Bacterial colonization occurred irrespective of the method used to induce the ulcer. This study demonstrates that colonization of gastric ulcers in rats occurs rapidly and significantly impairs ulcer healing. This effect appeared to be primarily attributable to gram-negative bacteria.

Sign in / Sign up

Export Citation Format

Share Document