Thermo Scientific™ Brilliance™ ESBL/ Brilliance™ CRE agar provides rapid detection of multiresistant Gram-negative organisms

2016 ◽  
Author(s):  
Emma Scopes
Keyword(s):  
Rapid Detection ◽  
Gram Negative ◽  
Gram Negative Organisms

Use of Limulus Lysate for Detecting Gram-Negative Neonatal Meningitis

PEDIATRICS ◽  
1976 ◽  
Vol 58 (1) ◽  
pp. 105-109
Author(s):  
Donald Dyson ◽  
George Cassady
Keyword(s):  
Bacterial Meningitis ◽  
Rapid Detection ◽  
Newborn Infants ◽  
Blood Cultures ◽  
Neonatal Meningitis ◽  
Gram Positive ◽  
Specific Test ◽  
Gram Negative ◽  
Gram Negative Organisms ◽  
Limulus Test

The Limulus, lysate test was evaluated as a method for rapid detection of neonatal gram-negative bacterial meningitis. A total of 208 CSF samples were collected from 145 newborn infants suspected of having meningitis. Initial samples from all six babies with culture-proven gram-negative bacterial meningitis had positive Limulus tests within 30 minutes of incubation. Samples from 14 infants with gram-negative organisms isolated only in blood and/or urine, as well as from four neonates with gram-positive organisms in CSF cultures and from 13 with gram-positive organisms in blood cultures all yielded negative Limulus tests. Thus, of 37 newborn infants with bacteria demonstrated in systemic cultures, only those six with gram-negative organisms in CSF had positive CSF Limulus tests. The CSF Limulus test was shown to be a rapid, reliable, and specific test for the detection of neonatal gram-negative bacterial meningitis.

scholarly journals Linearized esculentin-2EM shows pH dependent antibacterial activity with an alkaline optimum

2021 ◽  
Author(s):  
Erum Malik ◽  
David A. Phoenix ◽  
Timothy J. Snape ◽  
Frederick Harris ◽  
Jaipaul Singh ◽  
...  
Keyword(s):  
Helical Structure ◽  
Food Preservation ◽  
Forming Process ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Membranes ◽  
Gram Positive Bacteria ◽  
Alkaline Conditions ◽  
Ph Dependent ◽  
Gram Negative Organisms

AbstractHere the hypothesis that linearized esculentin 2EM (E2EM-lin) from Glandirana emeljanovi possesses pH dependent activity is investigated. The peptide showed weak activity against Gram-negative bacteria (MLCs ≥ 75.0 μM) but potent efficacy towards Gram-positive bacteria (MLCs ≤ 6.25 μM). E2EM-lin adopted an α-helical structure in the presence of bacterial membranes that increased as pH was increased from 6 to 8 (↑ 15.5–26.9%), whilst similar increases in pH enhanced the ability of the peptide to penetrate (↑ 2.3–5.1 mN m−1) and lyse (↑ 15.1–32.5%) these membranes. Theoretical analysis predicted that this membranolytic mechanism involved a tilted segment, that increased along the α-helical long axis of E2EM-lin (1–23) in the N → C direction, with −  < µH > increasing overall from circa − 0.8 to − 0.3. In combination, these data showed that E2EM-lin killed bacteria via novel mechanisms that were enhanced by alkaline conditions and involved the formation of tilted and membranolytic, α-helical structure. The preference of E2EM-lin for Gram-positive bacteria over Gram-negative organisms was primarily driven by the superior ability of phosphatidylglycerol to induce α-helical structure in the peptide as compared to phosphatidylethanolamine. These data were used to generate a novel pore-forming model for the membranolytic activity of E2EM-lin, which would appear to be the first, major reported instance of pH dependent AMPs with alkaline optima using tilted structure to drive a pore-forming process. It is proposed that E2EM-lin has the potential for development to serve purposes ranging from therapeutic usage, such as chronic wound disinfection, to food preservation by killing food spoilage organisms.

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