Isolation and Characterization of Multidrug-Resistant Gram-Negative Bacteria Found in Free-Ranging Long-Eared Hedgehogs (Erinaceus concolor) From Tabriz, Iran

2015 ◽  
Vol 24 (2) ◽  
pp. 235-239
Author(s):  
Payman Zare ◽  
Hassan Ghorbani-Choboghlo
2009 ◽  
Vol 51 (1) ◽  
pp. 46 ◽  
Author(s):  
Maiko Sato ◽  
Ashraf M Ahmed ◽  
Ayako Noda ◽  
Hitoshi Watanabe ◽  
Yukio Fukumoto ◽  
...  

1981 ◽  
Vol 59 (11-12) ◽  
pp. 877-879 ◽  
Author(s):  
Joseph H. Banoub ◽  
Derek H. Shaw

The amino sugar 3-acetamido-3,6-dideoxy-L-glucose has been isolated and characterized from the core oligosaccharide obtained from the bacterial lipopolysaccharides of Aeromonas hydrophila and Vibrio anguillarum. This is the first occasion in which a dideoxyamino sugar has been confirmed as a constituent of the core oligosaccharide rather than the O-polysaccharide.


2015 ◽  
Vol 61 (6) ◽  
pp. 429-435 ◽  
Author(s):  
C.S. Neethu ◽  
K.M. Mujeeb Rahiman ◽  
A.V. Saramma ◽  
A.A. Mohamed Hatha

Isolation and characterization of heterotrophic Gram-negative bacteria was carried out from the sediment and water samples collected from Kongsfjord, Arctic. In this study, the potential of Arctic bacteria to tolerate heavy metals that are of ecological significance to the Arctic (selenium (Se), mercury (Hg), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) was investigated. Quantitative assay of 130 isolates by means of plate diffusion and tube dilution methods was carried out by incorporation of different concentrations of metals. Growth in Se and Pb at a concentration of 3000 μg/L was significantly lower (P ≤ 0.0001) than at 2000 μg/L. The minimum inhibitory concentration for Cd and Hg was 50 μg/L (P ≤ 0.0001, F = 264.23 and P ≤ 0.0001, F = 291.08, respectively) even though in the tube dilution test, Hg-containing tubes showed much less growth, revealing its superior toxicity to Cd. Thus, the level of toxicity of heavy metals was found to be in the order of Hg > Cd > Cu > Zn > Pb > Se. Multiple-metal-resistant isolates were investigated for their resistance against antibiotics, and a positive correlation was observed between antibiotic and metal resistance for all the isolates tested. The resistant organisms thus observed might influence the organic and inorganic cycles in the Arctic and affect the ecosystem.


2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.


2021 ◽  
Author(s):  
Xukai Jiang ◽  
Nitin A. Patil ◽  
Mohammad A. K. Azad ◽  
Hasini Wickremasinghe ◽  
Heidi Yu ◽  
...  

Multidrug-resistant Gram-negative bacteria have been an urgent threat to global public health. Novel antibiotics are desperately needed to combat these 'superbugs'.


Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 340
Author(s):  
Raquel Bandeira da Silva ◽  
Mauro José Salles

Gram-negative bacteria (GNB), including multidrug-resistant (MDR) pathogens, are gaining importance in the aetiology of prosthetic joint infection (PJI). This retrospective observational study identified independent risk factors (RFs) associated with MDR-GNB PJI and their influence on treatment outcomes. We assessed MDR bacteria causing hip and knee PJIs diagnosed at a Brazilian tertiary hospital from January 2014 to July 2018. RFs associated with MDR-GNB PJI were estimated by bivariate and multivariate analyses using prevalence ratios (PRs) with significance at p < 0.05. Kaplan–Meier analysis was performed to evaluate treatment outcomes. Overall, 98 PJI patients were analysed, including 56 with MDR-GNB and 42 with other bacteria. Independent RFs associated with MDR-GNB PJI were revision arthroplasty (p = 0.002), postoperative hematoma (p < 0.001), previous orthopaedic infection (p = 0.002) and early infection (p = 0.001). Extensively drug-resistant GNB (p = 0.044) and comorbidities (p = 0.044) were independently associated with MDR-GNB PJI treatment failure. In sum, MDR-GNB PJI was independently associated with previous orthopaedic surgery, postoperative local complications and pre-existing infections and was possibly related to selective pressure on bacterial skin colonisation by antibiotics prescribed for early PJI. Infections due to MDR-GNB and comorbidities were associated with higher treatment failure rates.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shira Mandel ◽  
Janna Michaeli ◽  
Noa Nur ◽  
Isabelle Erbetti ◽  
Jonathan Zazoun ◽  
...  

AbstractNew antimicrobial agents are urgently needed, especially to eliminate multidrug resistant Gram-negative bacteria that stand for most antibiotic-resistant threats. In the following study, we present superior properties of an engineered antimicrobial peptide, OMN6, a 40-amino acid cyclic peptide based on Cecropin A, that presents high efficacy against Gram-negative bacteria with a bactericidal mechanism of action. The target of OMN6 is assumed to be the bacterial membrane in contrast to small molecule-based agents which bind to a specific enzyme or bacterial site. Moreover, OMN6 mechanism of action is effective on Acinetobacter baumannii laboratory strains and clinical isolates, regardless of the bacteria genotype or resistance-phenotype, thus, is by orders-of-magnitude, less likely for mutation-driven development of resistance, recrudescence, or tolerance. OMN6 displays an increase in stability and a significant decrease in proteolytic degradation with full safety margin on erythrocytes and HEK293T cells. Taken together, these results strongly suggest that OMN6 is an efficient, stable, and non-toxic novel antimicrobial agent with the potential to become a therapy for humans.


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