scholarly journals In-vitro postantibiotic effect (PAE) of ciprofloxacin against different bacterial species

2021 ◽  
Vol 7 (4) ◽  
pp. 262-264
Author(s):  
Abdelrahman M A Saeed
Keyword(s):  
Bacterial Species ◽  
Postantibiotic Effect

Production of Novel Bioactive Compounds by the Bacteria Associated with Some Marine Sponges of Gulf of Mannar and Palk Bay, Southeast Coast of India

2018 ◽  
Vol 6 (8) ◽  
pp. 183
Author(s):  
V. Ramadas ◽  
G. Chandralega
Keyword(s):  
Bioactive Compounds ◽  
Bacterial Species ◽  
Marine Sponges ◽  
Marine Organisms ◽  
Gulf Of Mannar ◽  
Bacterial Symbionts ◽  
Palk Bay ◽  
Excellent Source

Sponges, exclusively are aquatic and mostly marine, are found from the deepest oceans to the edge of the sea. There are approximately 15,000 species of sponges in the world, of which, 150 occur in freshwater, but only about 17 are of commercial value. A total of 486 species of sponges have been identified in India. In the Gulf of Mannar and Palk Bay a maximum of 319 species of sponges have been recorded. It has been proved that marine organisms are excellent source of bioactive secondary metabolites and number of compounds of originated from marine organisms had been reported to possess in-vitro and in-vivo immuno stimulatory activity. Extracts from 20 sponge species were tested for bacterial symbionts and bioactive compounds were isolated from such associated bacterial species in the present study.

Molecular Detection of Bacterial Pathogens Directly from the Nasal Swabs and Lung Tissue of Sheep and Goats

2019 ◽  
Vol 15 (02) ◽  
pp. 22-25
Author(s):  
Sunaina Thakur ◽  
Subhash Verma ◽  
Prasenjit Dhar ◽  
Mandeep Sharma
Keyword(s):  
Pasteurella Multocida ◽  
Direct Detection ◽  
Bacterial Species ◽  
Economic Losses ◽  
Isolation And Identification ◽  
Sheep And Goats ◽  
Histophilus Somni ◽  
Nasal Swabs ◽  
Mycoplasma Spp

Respiratory infections of sheep and goats cause heavy morbidity and mortality, leading to huge economic losses. Conventional methods of diagnosis that include isolation and identification of incriminating microbes are time-consuming and fraught with logistic challenges. Direct detection of incriminating microbes using molecular tools is gaining popularity in clinical, microbiological settings. In this study, a total of 50 samples (44 nasal swabs and 6 lung tissues) from sheep and goats were screened for the detection of different bacterial species by in vitro amplification of genus or species-specific genes. Histophilus somni was detected in 2% goat samples, Trueperella pyogenes in 20% goat nasal swabs, whereas 22% goat nasal swab samples were found positive for Mycoplasma spp. None of the samples from sheep was detected positive for H. somni, T. pyogenes, Mycoplasma spp. Similarly, all samples, irrespective, whether from sheep or goats, showed negative results for Pasteurella multocida, Mannheimia haemolytica, and Corynebacterium pseudotuberculosis.

scholarly journals Enhancing Terpene Yield from Sugars via Novel Routes to 1-Deoxy-d-Xylulose 5-Phosphate

2014 ◽  
Vol 81 (1) ◽  
pp. 130-138 ◽  
Author(s):  
James Kirby ◽  
Minobu Nishimoto ◽  
Ruthie W. N. Chow ◽  
Edward E. K. Baidoo ◽  
George Wang ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Xylose Reductase ◽  
Pentose Phosphate ◽  
Terpene Biosynthesis ◽  
Content Type ◽  
E Coli ◽  
Pathway Expression ◽  
Terpene Synthesis ◽  
Selection For

ABSTRACTTerpene synthesis in the majority of bacterial species, together with plant plastids, takes place via the 1-deoxy-d-xylulose 5-phosphate (DXP) pathway. The first step of this pathway involves the condensation of pyruvate and glyceraldehyde 3-phosphate by DXP synthase (Dxs), with one-sixth of the carbon lost as CO2. A hypothetical novel route from a pentose phosphate to DXP (nDXP) could enable a more direct pathway from C5sugars to terpenes and also circumvent regulatory mechanisms that control Dxs, but there is no enzyme known that can convert a sugar into its 1-deoxy equivalent. Employing a selection for complementation of adxsdeletion inEscherichia coligrown on xylose as the sole carbon source, we uncovered two candidate nDXP genes. Complementation was achieved either via overexpression of the wild-typeE. coliyajOgene, annotated as a putative xylose reductase, or via various mutations in the nativeribBgene.In vitroanalysis performed with purified YajO and mutant RibB proteins revealed that DXP was synthesized in both cases from ribulose 5-phosphate (Ru5P). We demonstrate the utility of these genes for microbial terpene biosynthesis by engineering the DXP pathway inE. colifor production of the sesquiterpene bisabolene, a candidate biodiesel. To further improve flux into the pathway from Ru5P, nDXP enzymes were expressed as fusions to DXP reductase (Dxr), the second enzyme in the DXP pathway. Expression of a Dxr-RibB(G108S) fusion improved bisabolene titers more than 4-fold and alleviated accumulation of intracellular DXP.

scholarly journals Volatile scents of influenza A and S. pyogenes (co-)infected cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Selina Traxler ◽  
Gina Barkowsky ◽  
Radost Saß ◽  
Ann-Christin Klemenz ◽  
Nadja Patenge ◽  
...  
Keyword(s):  
Influenza A ◽  
Early Recognition ◽  
Bacterial Species ◽  
Bacterial Load ◽  
Gas Chromatography Mass Spectrometry ◽  
Sampling System ◽  
Infected Cells ◽  
Infection Processes ◽  
Non Destructive

AbstractInfluenza A is a serious pathogen itself, but often leads to dangerous co-infections in combination with bacterial species such as Streptococcus pyogenes. In comparison to classical biochemical methods, analysis of volatile organic compounds (VOCs) in headspace above cultures can enable destruction free monitoring of metabolic processes in vitro. Thus, volatile biomarkers emitted from biological cell cultures and pathogens could serve for monitoring of infection processes in vitro. In this study we analysed VOCs from headspace above (co)-infected human cells by using a customized sampling system. For investigating the influenza A mono-infection and the viral-bacterial co-infection in vitro, we analysed VOCs from Detroit cells inoculated with influenza A virus and S. pyogenes by means of needle-trap micro-extraction (NTME) and gas chromatography mass spectrometry (GC-MS). Besides the determination of microbiological data such as cell count, cytokines, virus load and bacterial load, emissions from cell medium, uninfected cells and bacteria mono-infected cells were analysed. Significant differences in emitted VOC concentrations were identified between non-infected and infected cells. After inoculation with S. pyogenes, bacterial infection was mirrored by increased emissions of acetaldehyde and propanal. N-propyl acetate was linked to viral infection. Non-destructive monitoring of infections by means of VOC analysis may open a new window for infection research and clinical applications. VOC analysis could enable early recognition of pathogen presence and in-depth understanding of their etiopathology.

Development of a Cavity Disinfectant Containing Antibacterial Monomer MDPB

2016 ◽  
Vol 95 (13) ◽  
pp. 1487-1493 ◽  
Author(s):  
N. Hirose ◽  
R. Kitagawa ◽  
H. Kitagawa ◽  
H. Maezono ◽  
A. Mine ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bond Strength ◽  
Bacterial Species ◽  
Oral Bacteria ◽  
Resin Cement ◽  
Resin Cements ◽  
Adhesive Resin ◽  
Significant Difference ◽  
Adhesive Resin Cement

An experimental cavity disinfectant (ACC) that is intended to be used for various direct and indirect restorations was prepared by adding an antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB) at 5% into 80% ethanol. The antibacterial effectiveness of ACC and its influences on the bonding abilities of resin cements were investigated. To examine the antibacterial activity of unpolymerized MDPB, the minimum inhibitory and bactericidal concentrations (MIC and MBC) were determined for Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, Parvimonas micra, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis. Antibacterial activities of ACC and the commercial cavity disinfectant containing 2% chlorhexidine and ethanol (CPS) were evaluated by agar disk diffusion tests through 7 bacterial species and by MIC and MBC measurement for S. mutans. The effects of ACC and CPS to kill bacteria in dentinal tubules were compared with an S. mutans–infected dentin model. Shear bond strength tests were used to examine the influences of ACC on the dentin-bonding abilities of a self-adhesive resin cement and a dual-cure resin cement used with a primer. Unpolymerized MDPB showed strong antibacterial activity against 7 oral bacteria. ACC produced inhibition zones against all bacterial species similar to CPS. For ACC and CPS, the MIC value for S. mutans was identical, and the MBC was similar with only a 1-step dilution difference (1:2). Treatment of infected dentin with ACC resulted in significantly greater bactericidal effects than CPS ( P < 0.05, analysis of variance and Tukey’s honest significant difference test). ACC showed no negative influences on the bonding abilities to dentin for both resin cements, while CPS reduced the bond strength of the self-adhesive resin cement ( P < 0.05). This study clarified that the experimental cavity disinfectant containing 5% MDPB is more effective in vitro than the commercially available chlorhexidine solution to eradicate bacteria in dentin, without causing any adverse influences on the bonding abilities of resinous luting cements.

scholarly journals Dietary Fucose Affects Macrophage Polarization and Reproductive Performance in Mice

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 855
Author(s):  
Ekaterina A. Litvinova ◽  
Victoria D. Bets ◽  
Natalya A. Feofanova ◽  
Olga V. Gvozdeva ◽  
Kseniya M. Achasova ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Reproductive Performance ◽  
Immune Status ◽  
Macrophage Polarization ◽  
Bacterial Species ◽  
Peritoneal Macrophages ◽  
M2 Macrophage ◽  
Female Mice ◽  
Intestinal Mucus

Intestinal mucus protects epithelial and immune cells from the gut resident microorganisms, and provides growth-promoting factors as mucus-derived O-glycans for beneficial bacteria. A lack of intestinal protective mucus results in changes in the commensal microflora composition, mucosal immune system reprogramming, and inflammation. Previous work has shown that fucose, the terminal glycan chain component of the intestinal glycoprotein Mucin2, and fucoidan polysaccharides have an anti-inflammatory effect in some mouse models of colitis. This study evaluates the effect of fucose on reproductive performance in heterozygous mutant Muc2 female mice. We found that even though Muc2+/− females are physiologically indistinguishable from C57Bl/6 mice, they have a significantly reduced reproductive performance upon dietary fucose supplementation. Metagenomic analysis reveals that the otherwise healthy wild-type siblings of Muc2−/− animals have reduced numbers of some of the intestinal commensal bacterial species, compared to C57BL/6 mice. We propose that the changes in beneficial microflora affect the immune status in Muc2+/− mice, which causes implantation impairment. In accordance with this hypothesis, we find that macrophage polarization during pregnancy is impaired in Muc2+/− females upon addition of fucose. Metabolic profiling of peritoneal macrophages from Muc2+/− females reveals their predisposition towards anaerobic glycolysis in favor of oxidative phosphorylation, compared to C57BL/6-derived cells. In vitro experiments on phagocytosis activity and mitochondrial respiration suggest that fucose affects oxidative phosphorylation in a genotype-specific manner, which might interfere with implantation depending on the initial status of macrophages. This hypothesis is further confirmed in BALB/c female mice, where fucose caused pregnancy loss and opposed implantation-associated M2 macrophage polarization. Taken together, these data suggest that intestinal microflora affects host immunity and pregnancy outcome. At the same time, dietary fucose might act as a differential regulator of macrophage polarization during implantation, depending on the immune status of the host.

In vitro evaluation of the effect of nicotine, cotinine, and caffeine on oral microorganisms

2008 ◽  
Vol 54 (6) ◽  
pp. 501-508 ◽  
Author(s):  
Karina Cogo ◽  
Michelle Franz Montan ◽  
Cristiane de Cássia Bergamaschi ◽  
Eduardo D. Andrade ◽  
Pedro Luiz Rosalen ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Culture Media ◽  
Bacterial Species ◽  
In Vitro Study ◽  
Bacterial Strains ◽  
Planktonic Cells ◽  
Susceptibility Tests

The aim of this in vitro study was to evaluate the effects of nicotine, cotinine, and caffeine on the viability of some oral bacterial species. It also evaluated the ability of these bacteria to metabolize those substances. Single-species biofilms of Streptococcus gordonii , Porphyromonas gingivalis , or Fusobacterium nucleatum and dual-species biofilms of S. gordonii – F. nucleatum and F. nucleatum – P. gingivalis were grown on hydroxyapatite discs. Seven species were studied as planktonic cells, including Streptococcus oralis , Streptococcus mitis , Propionibacterium acnes , Actinomyces naeslundii , and the species mentioned above. The viability of planktonic cells and biofilms was analyzed by susceptibility tests and time-kill assays, respectively, against different concentrations of nicotine, cotinine, and caffeine. High-performance liquid chromatography was performed to quantify nicotine, cotinine, and caffeine concentrations in the culture media after the assays. Susceptibility tests and viability assays showed that nicotine, cotinine, and caffeine cannot reduce or stimulate bacterial growth. High-performance liquid chromatography results showed that nicotine, cotinine, and caffeine concentrations were not altered after bacteria exposure. These findings indicate that nicotine, cotinine, and caffeine, in the concentrations used, cannot affect significantly the growth of these oral bacterial strains. Moreover, these species do not seem to metabolize these substances.

scholarly journals THE RATE OF BACTERICIDAL ACTION OF PENICILLIN IN VITRO AS A FUNCTION OF ITS CONCENTRATION, AND ITS PARADOXICALLY REDUCED ACTIVITY AT HIGH CONCENTRATIONS AGAINST CERTAIN ORGANISMS

1948 ◽  
Vol 88 (1) ◽  
pp. 99-131 ◽  
Author(s):  
Harry Eagle ◽  
A. D. Musselman
Keyword(s):  
Bacterial Species ◽  
Fold Increase ◽  
Bactericidal Effect ◽  
Penicillin G ◽  
Bacterial Suspension ◽  
Maximal Effect ◽  
Maximal Rate ◽  
Effective Level ◽  
High Concentrations

1. The concentrations of penicillin G which (a) reduced the net rate of multiplication, (b) exerted a net bactericidal effect, and (c) killed the organisms at a maximal rate, have been defined for a total of 41 strains of α- and ß-hemolytic streptococci, Staphylococcus aureus and Staphylococcus albus, Diplococcus pneumoniae, and the Reiter treponoma. 2. The concentration which killed the organisms at a maximal rate was 2 to 20 times the minimal effective level ("sensitivity" as ordinarily defined). With some organisms, even a 32,000-fold increase beyond this maximally effective level did not further increase the rate of its bactericidal effect. However, with approximately half the strains here studied (all 4 strains of group B ß-hemolytic streptococci, 4 of 5 group C strains, 5 of 7 strains of Streptococcus fecalis, 2 of 4 other α-hemolytic streptococci, and 4 of 9 strains of staphylococci), when the concentration of penicillin was increased beyond that optimal level, the rate at which the organisms died was paradoxically reduced rather than increased, so that the maximal effect was obtained only within a relatively narrow optimal zone. 3. There were marked differences between bacterial species, and occasionally between different strains of the same species, not only with respect to the effective concentrations of penicillin, but also with respect to the maximal rate at which they could be killed by the drug in any concentration. Although there was a rough correlation between these two factors, there were many exceptions; individual strains affected only by high concentrations of penicillin might nevertheless be killed rapidly, while strains sensitive to minute concentrations might be killed only slowly. 4. Within the same bacterial suspension, individual organisms varied only to a minor degree with respect to the effective concentrations of penicillin. They varied strikingly, however, in their resistance to penicillin as measured by the times required to kill varying proportions of the cells.

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