scholarly journals Morphological and adhesive properties of Klebsiella pneumoniae biofilms

2020 ◽  
Vol 13 (1) ◽  
pp. 197-200 ◽  
Author(s):  
Ekaterina Lenchenko ◽  
Dmitry Blumenkrants ◽  
Nadezhda Sachivkina ◽  
Nadezhda Shadrova ◽  
Alfia Ibragimova
Keyword(s):  
Klebsiella Pneumoniae ◽  
Optical Density ◽  
Gentian Violet ◽  
Practical Importance ◽  
Adhesive Properties ◽  
Ether Mixture ◽  
Density Indices ◽  
Optical Density Index ◽  
Adhesion Index

Background and Aim: The study of biofilm-forming ability of Gram-negative microflora has great practical importance for assessing the effectiveness of antibiotic therapy and finding new ways to diagnose and inhibit the growth of biofilms. This is because poor penetration of antibacterial drugs into the biofilm can lead to the selection of resistant strains and has a consequence evident by the occurrence of relapse of infection in animals. This study aimed to evaluate morphological and densitometric indicators of biofilm formation as well as adhesive properties of Klebsiella pneumoniae. Materials and Methods: K. pneumoniae was cultured at 37°C for 2-144 h in vitro. The specimens for optical microscopy were prepared by fixation with a 1:1 alcohol-ether mixture for 10 min and stained with a 0.5% solution of gentian violet for 2 min, and the optical density index was evaluated at a wavelength of 490 nm. Further, the adhesive properties of the microorganisms were determined at a concentration of 1 billion/ml and a suspension of ram erythrocytes at a concentration of 100 million/ml when cultured at 37°C for 24 h. Blood smears were prepared and stained with 0.5% gentian violet. Results: K. pneumonia cultured at 37°C after 24 h on the meat peptone agar formed large, convex, mucous, and white colonies (d=3.0-6.0 mm). With the growth in the meat and peptone broth, uniform turbidity of the medium was observed. Analyzing the optical density indices (density, D), it was found that K. pneumoniae were good producers of biofilms (D=0.528±0.31). Data for indicators of adhesive properties of K. pneumoniae were as follows: Average adhesion index, 4.56±0.14; adhesion coefficient, 1.07±0.52; and adhesion index, 4.26±0.07. The studied bacteria had high adhesive activity. A direct correlation dependence (R=0.94) of the optical density of biofilms (D≥0.514-0.551) and AAI (4.15±0.28-4.76±0.75) was established. Conclusion: This study has demonstrated that K. pneumoniae had high adhesive activity, was strong producer of biofilms, and the optical density of the sample exceeded the optical density of the control by more than 4 times.

The ability of Salmonella enterica to biofilm formation in conditions of interspecific interaction with representatives of the intestinal microflora

2021 ◽  
pp. 75-80
Author(s):  
E.V. Matosova
Keyword(s):  
Optical Density ◽  
Intestinal Microbiota ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Intestinal Microflora ◽  
Gentian Violet ◽  
Density Measurement ◽  
Interspecific Interaction ◽  
E Coli

For effective distribution in the gastrointestinal tract, Salmonella must have the ability to form biofilms and compete for nutrients with the host microbiota. Objective: to characterize the ability of Salmonella enterica Typhimurium to biofilm formation under conditions of interspecific interaction in a multicultural biofilm with representatives of the intestinal microbiota in an in vitro experiment. Museum strains of the bacteria Salmonella enterica serovar Typhimurium, Lactobacillus acidophilus and Lactobacillus casei, Escherichia coli were used in the work. The process of interspecific interaction was modeled in a mixture of LB-broth with 0.85 % NaCl solution in a ratio of 1:3 at an initial bacterial concentration of 10³ CFU / ml in Petri dishes with a diameter of 65 mm at a temperature of +37 °C. The experimental results were evaluated within 12 days. The plate method was used to count the number of viable cells in biofilms. The optical density of the matrix of the biofilm stained with gentian violet was measured using spectrophotometry (wavelength 595 nm). To assess tinctorial properties, the bacterial samples were Gram-stained.. Enzymatic properties were assessed using Giss media and differential diagnostic media. All experiments were repeated 3 times. It was found that Salmonella enterica Typhimurium exhibit the ability to form biofilm. In the initial stages of biofilm formation, the bacteria of the intestinal microbiota suppress the development of Salmonella. In mature mixed biofilms, the growth of S. enterica and E. coli is mutually stimulated. By the end of the experiment, the dominance of Salmonella over the intestinal microbiota was noted. The results of the optical density measurement suggest the presence of species-specificity in bacterial interaction. Conclusion. Intestinal microbiota bacteria inhibit the growth of Salmonella bacteria in biofilms only in the initial stages. In mature mixed biofilms, the growth of E. coli and S. enterica is mutually stimulated, however, on the 12th day, Salmonella dominates over E. coli and Lactobacillus spp. (p > 0.05). English version of the article is available at URL: https://panor.ru/articles/ability-of-salmonella-enterica-to-biofilm-formation-under-conditions-of-interspecies-interaction-with-representatives-of-the-intestinal-microflora/72525.html

scholarly journals Antioxidants capabilities in correction of gentamicin-induced nephrotoxicity in experimental infection

2016 ◽  
Vol 97 (4) ◽  
pp. 572-578 ◽  
Author(s):  
A G Miroshnichenko ◽  
V M Brukhanov ◽  
I Ye Gossen ◽  
V Yu Perfilyev
Keyword(s):  
Escherichia Coli ◽  
Ascorbic Acid ◽  
Klebsiella Pneumoniae ◽  
Optical Density ◽  
Experimental Infection ◽  
Coli Strain ◽  
Bacterial Suspension ◽  
Bacterial Peritonitis

Aim. To assess the antioxidants effectiveness (ascorbic acid, methylethylpiridinol, N-acetylcysteine) in reducing the gentamicin-induced nephrotoxicity in experimental infection caused by Escherichia coli or Klebsiella pneumoniae.Methods. The experiment was divided into two parts. In the first part, the effect of antioxidants on the sensitivity of bacteria to gentamicin in vitro according to changing the optical density of the bacterial suspension, in the second part - nephroprotective activity of antioxidants and their effects on antibiotic activity in experimental bacterial peritonitis were evaluated.Results. All antioxidants significantly reduce the sensitivity of E. coli to gentamicin in vitro, and the level of effect is directly proportional to the antioxidant concentration. Methylethylpiridinol has the most pronounced antagonistic action against gentamicin. It is found that methylethylpiridinol at a concentration of 4 mmol/l enhances development of Escherichia coli strain by 7 times by the 6th hour of incubation. Ascorbic acid and N-acetylcysteine have a similar probacterial activity profile. In the incubation mixtures containing a strain of Klebsiella pneumoniae, a similar pattern of increase in bacterial biomass optical density was observed with maximum values in the presence of the highest concentrations of antioxidants. In experimental infection, antioxidants reduce the activity of gentamicin against Escherichia coli and Klebsiella pneumoniae, without reducing the antibiotic nephrotoxicity.Conclusion. Ascorbic acid, methylethylpiridinol and N-acetylcysteine reduce the antibacterial activity of gentamicin against Escherichia coli and Klebsiella pneumoniae in vitro and in vivo, in a dose of 80 mg/kg they do not reduce gentamicin nephrotoxicity in bacterial peritonitis in rats; their use in the course of treatment with gentamicin is not only irrational, but also contraindicated.

Activité antibactérienne de l’huile essentielle de Pelargonium x asperum et son potentiel synergique avec la nisine

2019 ◽  
Vol 17 (3) ◽  
pp. 140-148 ◽  
Author(s):  
A. Ouelhadj ◽  
L. Ait Salem ◽  
D. Djenane
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Nous Avons ◽  
Activité Antibactérienne

Ce travail vise l’étude de l’activité antibactérienne de l’huile essentielle (HE) de Pelargoniumx asperum et de la bactériocine, la nisine seul et en combinaison vis-à-vis de six bactéries dont quatre sont multirésistantes d’origine clinique. L’activité antibactérienne in vitro a été évaluée par la méthode de diffusion sur gélose. La concentration minimale inhibitrice (CMI) est aussi déterminée pour HE. Les résultats ont révélé une activité antibactérienne significative exercée par HE visà-vis de Staphylococcus aureus (ATCC 43300), Staphylococcus aureus et Escherichia coli avec des diamètres d’inhibition de 36,00 ; 22,50 et 40,00 mm, respectivement. Cependant, l’HE de Pelargonium asperum a montré une activité antibactérienne supérieure par rapport à la nisine. Les valeurs des CMI rapportées dans cette étude sont comprises entre 1,98–3,96 μl/ml. Les combinaisons réalisées entre HE et la nisine ont montré un effet additif vis-à-vis de Escherichia coli (ATCC 25922) avec (50 % HE Pelargonium asperum + 50 % nisine). Par contre, nous avons enregistré une synergie vis-à-vis de Klebsiella pneumoniae avec (75 % HE Pelargonium asperum + 25 % nisine) et contre Pseudomonas aeruginosa avec les trois combinaisons testées. Les résultats obtenus permettent de dire que l’HE de Pelargonium asperum possède une activité antibactérienne ainsi que sa combinaison avec la nisine pourrait représenter une bonne alternative pour la lutte contre l’antibiorésistance.

Hyperbaric oxygen suppresses growth of Klebsiella pneumoniae and enhances effect of tigecycline in vitro

2017 ◽  
Vol 44 (6) ◽  
pp. 543-549
Author(s):  
Lina Zhang ◽  
◽  
Qing Sun ◽  
Di Wu ◽  
Ying Yang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Hyperbaric Oxygen

scholarly journals Biosynthesis of Zinc Oxide Nanoparticles from Acacia nilotica (L.) Extract to Overcome Carbapenem-Resistant Klebsiella Pneumoniae

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1919
Author(s):  
Elsayim Rasha ◽  
AlOthman Monerah ◽  
Alkhulaifi Manal ◽  
Ali Rehab ◽  
Doud Mohammed ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Klebsiella Pneumoniae ◽  
Zinc Oxide Nanoparticles ◽  
Acacia Nilotica ◽  
Oxide Nanoparticles ◽  
Zno Nps ◽  
X Ray ◽  
Carbapenem Resistant

Recently, concerns have been raised globally about antimicrobial resistance, the prevalence of which has increased significantly. Carbapenem-resistant Klebsiella pneumoniae (KPC) is considered one of the most common resistant bacteria, which has spread to ICUs in Saudi Arabia. This study was established to investigate the antibacterial activity of biosynthesized zinc oxide nanoparticles (ZnO-NPs) against KPC in vitro and in vivo. In this study, we used the aqueous extract of Acacia nilotica (L.) fruits to mediate the synthesis of ZnO-NPs. The nanoparticles produced were characterized by UV-vis spectroscopy, zetasizer and zeta potential analyses, X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The antimicrobial activity of ZnO-NPs against KPC was determined via the well diffusion method, and determining minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the results showed low MIC and MBC when compared with the MIC and MBC of Imipenem and Meropenem antibiotics. The results of in vitro analysis were supported by the results upon applying ZnO-NP ointment to promote wound closure of rats, which showed better wound healing than the results with imipenem ointment. The biosynthesized ZnO-NPs showed good potential for use against bacteria due to their small size, applicability, and low toxicity to human cells.

scholarly journals Differences in a Single Extracellular Residue Underlie Adhesive Functions of Two Zebrafish Aqp0s

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2005
Author(s):  
Irene Vorontsova ◽  
James E. Hall ◽  
Thomas F. Schilling ◽  
Noriaki Nagai ◽  
Yosuke Nakazawa
Keyword(s):  
Cell Adhesion ◽  
Single Amino Acid ◽  
Amino Acid Difference ◽  
Adhesion Assay ◽  
Loss Of Function ◽  
Adhesive Properties ◽  
The Difference ◽  
In Vitro Adhesion ◽  
Cell To Cell Adhesion

Aquaporin 0 (AQP0) is the most abundant lens membrane protein, and loss of function in human and animal models leads to cataract formation. AQP0 has several functions in the lens including water transport and adhesion. Since lens optics rely on strict tissue architecture achieved by compact cell-to-cell adhesion between lens fiber cells, understanding how AQP0 contributes to adhesion would shed light on normal lens physiology and pathophysiology. We show in an in vitro adhesion assay that one of two closely related zebrafish Aqp0s, Aqp0b, has strong auto-adhesive properties while Aqp0a does not. The difference appears to be largely due to a single amino acid difference at residue 110 in the extracellular C-loop, which is T in Aqp0a and N in Aqp0b. Similarly, P110 is the key residue required for adhesion in mammalian AQP0, highlighting the importance of residue 110 in AQP0 cell-to-cell adhesion in vertebrate lenses as well as the divergence of adhesive and water permeability functions in zebrafish duplicates.

Sign in / Sign up

Export Citation Format

Share Document