Rapid spot test for the determination of esculin hydrolysis

1976 ◽  
Vol 4 (2) ◽  
pp. 180-184
Author(s):  
S C Edberg ◽  
K Gam ◽  
C J Bottenbley ◽  
J M Singer
Keyword(s):  
Agar Medium ◽  
Wide Spectrum ◽  
Hydrolysis Product ◽  
Spot Test ◽  
Gram Negative Bacteria ◽  
Ferric Ions ◽  
Gram Positive ◽  
Gram Negative ◽  
Esculin Hydrolysis

Esculin hydrolysis is a useful test in the differentiation of both gram-positive and gram-negative bacteria covering a wide spectrum of aerobes, facultative anaerobes, and anaerobes. Commonly utilized methods require a minimum of 18 h of incubation in broth or agar medium and utilize the production of a brown-black compound, due to the combination of ferric ions with the hydrolysis product esculetin, as indicator. A procedure is presented that requires 15 to 30 min for completion and utilizes fluorescence loss as the indicator of hydrolysis. Esculin fluoresces at 366 nm, whereas the hydrolysis product esculetin does not. Over 1,400 strains of gram-positive and gram-negative bacteria were tested. There was 98.4% of correlation between the spot test and esculin broth and 97% correlation with the bile-esculin agar.

Study of the chemical composition, antimicrobial activity of the essen- al oil of Cistus salviifolius from Tissemsilt National Park (Algeria) and influence of the drying period in the shade on the yield of this oil

2020 ◽  
Vol 9 (6) ◽  
pp. 238-244
Author(s):  
Meharrar Nadjet ◽  
Bekada Ahmed Mohamed Ali ◽  
Dris Ibrahim ◽  
Jacques Dommes ◽  
Arabi Abed ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Wide Spectrum ◽  
Diffusion Method ◽  
Bacterial Suspension ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Antibiotic Susceptibility Test ◽  
Cistus Salviifolius

The genera Cistus present groups of about twenty species of shrubs belon- ging to the Cistaceae family are very common throughout the Mediterranean region. Cistus salviifolius, known as Melliya is a species of this genus that occurs in the forest region of Mount Ouarsenis (northwest Algeria), exactly in Thniet El Had Na onal Park in the Wilaya of Tissemsilt. This study was un- dertaken to evaluate the an bacterial effects of C. salviifolius and its chemical composition in addition the effect of shade drying me on essen al oil yield in order to op mize this parameter which is most o en not controlled for producers. The op mal yield recorded is about 0.07± 0.02%. Its characte- riza on by gas chromatography coupled with mass spectrometry shows a dominance of hydrocarbon compounds. The minimum inhibitory concentration (MIC) is established using 6 strains of Gram-positive and negative bacteria. The antibiotic susceptibility test is performed using the giliose- environment diffusion method, a bacterial suspension is prepared and subsequently well homogenized. Opacity must be adjusted to 0.5 McF (McFarland), from a young exponen al culture (18 to 24 hours). The an mi- crobial ac vity of C. salviifolius EO was tested against three Gram-posi ve and three Gram-nega ve bacteria. In fact, a strong inhibitory and bactericidal effect has been demonstrated against all Gram-positive and Gram- negative bacteria tested. It appears from this study that the EO of C. salviifo- lius has a very high antimicrobial activity, it shows a wide spectrum covering Gram positive and Gram negative bacteria. Taking into account the results of this study, new an bacterial agents could be developed and the use of C.salviifolius should be encouraged in the pharmaceutical and perfumery industries.

ANTIMICROBIAL ACTIVITY OF COPPER KAOLINITE AND SURFACTANT MODIFIED COPPER KAOLINITE AGAINST GRAM POSITIVE AND GRAM NEGATIVE BACTERIA

2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Nor Syafawani Sarah Md Saad ◽  
Nik Ahmad Nizam Nik Malek ◽  
Chun Shiong Chong
Keyword(s):  
Antimicrobial Activity ◽  
Synergistic Effects ◽  
Wide Spectrum ◽  
Copper Nitrate ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Diffusion Technique

The aim of this research was to determine the antimicrobial activity of kaolinite modified with antimicrobial compounds against Gram positive and Gram negative bacteria. Copper kaolinite (Cu-kaolinite) was prepared by loading raw kaolinite with copper nitrate trihydrate (CuNO3) while surfactant modified Cu-kaolinite (SM-Cu-kaolinite) was prepared by adding cationic surfactants hexadecyltrimethyl ammonium (HDTMA) on Cu-Kaolinite. Samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyzer. The antimicrobial activity of the samples was tested against Gram negative bacteria (Escherichia coli ATCC 11229 and Pseudomonas aeruginosa ATCC 15442), and Gram positive bacteria (Staphylococcus aureus ATCC 6538 and Enterococcus faecalis ATCC 29212) through disc diffusion technique (DDT) and minimum inhibition concentration (MIC). The results showed that the antimicrobial activity of Cu-kaolinite increased after modified with HDTMA due to the synergistic effects of Cu ions and HDTMA molecules on the kaolinite. The antimicrobial activity for surfactant modified Cu-kaolinite was greater for Gram positive bacteria compared to Gram negative bacteria. In conclusion, the attachment of HDTMA on Cu-kaolinite contributed to the enhanced antimicrobial activity against wide spectrum of bacteria (Gram positive and Gram negative bacteria).

scholarly journals Evernimicin Binds Exclusively to the 50S Ribosomal Subunit and Inhibits Translation in Cell-Free Systems Derived from both Gram-Positive and Gram-Negative Bacteria

2000 ◽  
Vol 44 (5) ◽  
pp. 1121-1126 ◽  
Author(s):  
Paul M. McNicholas ◽  
David J. Najarian ◽  
Paul A. Mann ◽  
David Hesk ◽  
Roberta S. Hare ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Dissociation Constants ◽  
Wide Spectrum ◽  
Ribosomal Subunit ◽  
Gram Negative Bacteria ◽  
Metabolic Labeling ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Free Translation

ABSTRACT Evernimicin (SCH 27899) is a new antibiotic with activity against a wide spectrum of gram-positive bacteria and activity against some gram-negative bacteria. Previous metabolic labeling studies indicated that evernimicin specifically inhibited protein synthesis inStaphylococcus aureus. Using a susceptibleEscherichia coli strain, we demonstrated that evernimicin also inhibited protein synthesis in E. coli. In cell-free translation assays with extracts from either E. coli orS. aureus, evernimicin had a 50% inhibitory concentration of approximately 125 nM. In contrast, cell-free systems derived from wheat germ and rabbit reticulocytes were inhibited only by very high levels of evernimicin. Evernimicin did not promote transcript misreading. [14C]evernimicin specifically bound to the 50S subunit from E. coli. Nonlinear regression analysis of binding data generated with 70S ribosomes from E. coli andS. aureus and 50S subunits from E. colireturned dissociation constants of 84, 86, and 160 nM, respectively. In binding experiments, performed in the presence of excess quantities of a selection of antibiotics known to bind to the 50S subunit, only the structurally similar drug avilamycin blocked binding of [14C]evernimicin to ribosomes.

scholarly journals Determination of Patulin By TLC From Mouldy Apples

2010 ◽  
Vol 34 (1) ◽  
pp. 201-207
Author(s):  
Omar J. Al saree
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Inhibitory Effect ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Tlc Plates

Analysis of the decayed apples (van. Starking delicious), collected from the localmarket, for patulin mycotoxin, using column chromotography and TLC Plates showedthat the presence of the amount of patulin mycotoxin in the mouldy tissues (1.3 , 2.5 ,3.4 , 4.2, 5.5, and 6.4 ) cm in diameters were (5.1, 5.8, 6.3, 10.5, 12.3, and 14 ) μgpatulin/g moldy tissues respectively. According to this research also, Patulinmycotoxin could diffused to the surrounding mouldy tissues. It is found that (0.5and0.2), (1.0 and 0.5), and (1.5 and 0.5) μg patulin/g tissues in the first and secondcentimeters after mouldy tissues 4.2, 5.5 and 6.4 cm respectively, this phenomenondue to the presence of intracellular spaces in the tissues which allow to patulin todiffuse from mouldy to the healthy tissues there was no patulin found in the othersurrounding healthy tissues. Gram positive bacteria found to be more susceptible topatulin, the zone of inhibition against Staphyllococcus aureus was 10 to 11 mm indiameter at concentration 10 and 30 mg /ml respectively when compared with 0.3μg/ml streptomycin and 0.06 μg/ml ciprofloxacin while no inhibitory effect foundagainst Gram negative bacteria Klebsiella pneumoniae and Escherichia coli

scholarly journals New Detection Platform for Screening Bacteria in Liquid Samples

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 142
Author(s):  
Rita La La Spina ◽  
Diana C. C. António ◽  
Radoslaw Bombera ◽  
Teresa Lettieri ◽  
Anne-Sophie Lequarré ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Proof Of Concept ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Liquid Samples ◽  
Detection And Identification ◽  
Small Set ◽  
Highly Porous

The development of sensitive methods for the determination of potential bacterial contamination is of upmost importance for environmental monitoring and food safety. In this study, we present a new method combining a fast pre-enrichment step using a microporous cryogel and a detection and identification step using antimicrobial peptides (AMPs) and labelled antibodies, respectively. The experimental method consists of: (i) the capture of large amounts of bacteria from liquid samples by using a highly porous and functionalized cryogel; (ii) the detection and categorisation of Gram-positive and Gram-negative bacteria by determining their affinities toward a small set of AMPs; and (iii) the identification of the bacterial strain by using labelled detection antibodies. As proof of concept, the assessment of the three steps of the analysis was performed by using Escherichia coli and Bacillus sp. as models for Gram-negative and Gram-positive bacteria, respectively. The use of AMPs with broad specificity combined with labelled antibodies enabled the detection and potential categorization of a large spectrum of unknown or unexpected bacteria.

scholarly journals Activity of Engineered Nano-Semiconductor Oxides against Gram Positive and Gram Negative Bacteria

2019 ◽  
Vol 8 (4S2) ◽  
pp. 645-650
Keyword(s):  
Wide Spectrum ◽  
Antibacterial Activities ◽  
Engineered Nanoparticles ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Bacillus Brevis ◽  
Gram Negative ◽  
E Coli ◽  
Semiconductor Oxides

Antibacterial activities of semiconductor oxides such as ZnO and TiO2 have induced research on the design of engineered nanoparticles (ENPs) for the last few decades. We had synthesized modified ZnO and TiO2 using rare earth salts and analyzed their antibacterial activities against Bacillus brevis. (Gram positive) and E. coli (Gram negative) by modified well diffusion method. Among the seventeen nanoparticles studied, Ag-TiO2 showed highest antibacterial activity against Gram positive and Gram negative bacteria. Antibacterial activities of Ni-Ag-TiO2, ZnO, Eu2O3-ZnO, DyMoO4-ZnO, GdMoO4-ZnO, DyVO4-ZnO, GdVO4-ZnO and HoVO4-ZnO were found to be significant. From the microbial plating experiments it was shown that the synthesized nano materials show a wide spectrum of antibacterial activities performed against Bacillus brevis, and E. coli. In this study we help to understand the influence of the engineered nanoparticles (ENPs) against microbes, as these ENPs finds wide applications in medicine, water treatment, in food industry as anti-coating agents.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

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