scholarly journals OBSERVATIONS ON THE GROWTH OF BACTERIA ON MEDIA CONTAINING VARIOUS ANILIN DYES

1914 ◽  
Vol 19 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Charles Krumwiede ◽  
Josephine S. Pratt

Gentian violet and allied anilin dyes have a similar influence on bacterial growth, dividing bacteria into two groups corresponding in general to their reaction to the Gram stain. Among Gram-negative bacteria a strain is occasionally encountered which will not grow on violet agar, differentiating it from other members of the same species or variety. The reaction is quantitative, although the quantitative character is more marked with some species than with others. The streptococcus-pneumococcus group differ from other Gram-positive bacteria in their ability to grow in the presence of amounts of dye sufficient to inhibit the other species. The dysentery bacillus group shows marked variation in the presence of dyes. In the case of fuchsin the variation approaches closely a specific difference between the dysentery and paradysentery groups. The variations of the latter groups with other dyes show no correlation with the common differential characteristics. A closer study might reveal variations in other characteristics which would parallel the different reactions to dyes. Decolorization with sodium sulphite robs the dyes of some of their inhibitive powers.

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.


2002 ◽  
Vol 46 (9) ◽  
pp. 3071-3074 ◽  
Author(s):  
Hee-Jeong Yun ◽  
Yu-Hong Min ◽  
Jung-A Lim ◽  
Jin-Wook Kang ◽  
So-Young Kim ◽  
...  

ABSTRACT The in vitro and in vivo activities of DW286, a novel fluoronaphthyridone with potent antibacterial activity, were compared with those of ciprofloxacin, gemifloxacin, sparfloxacin, and trovafloxacin. Against gram-positive bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Enterococcus faecalis, the in vitro activity of DW286 was stronger than that of any other reference antibiotic. Against gram-negative bacteria, the activity of DW286 was similar to those of trovafloxacin and gemifloxacin but was weaker than that of ciprofloxacin. In a mouse systemic infection caused by three S. aureus strains, including methicillin-resistant S. aureus and quinolone-resistant S. aureus (QRSA), DW286 demonstrated the most potent activity, as found in vitro. Specially, DW286 is ≥8-fold more active against QRSA than the other fluoroquinolones. And the 50% protective doses for DW286 were correspondent with the in vitro activities.


1981 ◽  
Vol 44 (8) ◽  
pp. 633-647 ◽  
Author(s):  
JON J. KABARA

Now that energy has become a world problem, cheap, effective chemical preservation is critical. This discussion forwards a new concept in food preservation. The concept is based on a ‘systems’ approach, using three common foodstuffs: monolaurin, food-grade phenolics and chelator, three multifunctional food materials, whose history as potential preservatives is reviewed. Although monolaurin (Lauricidin) is a Generally Recognized As Safe chemical, its use as part of a ‘preservative system’ is new. Comparisons of its germicidal activity by investigators have shown it to be more effective than proprionates, benzoates and even sorbic acid. The common antioxidants, tert-butylhydroxytoluene (BHT) or tert-butylhydroxyanisole (BHA) have been shown since 1967 to affect a number of different microorganisms, including viruses. The chelator ethylenediamineacetate (EDT A) has weak biocidal activity on its own but can potentiate the effect of the first two biocidal agents, particularly against gram-negative bacteria. The three common food chemicals therefore become part of a ‘preservative system’. The amount and ratio of one to the other is determined by the specific need for microbiological protection.


1936 ◽  
Vol 64 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Malcolm H. Merrill

Evidence is presented that some viruses behave like proteins in that they are inactivated by proteolytic enzymes, whereas others prove more or less resistant. Ten strains of living Gram-negative bacteria resisted the action of purified trypsin and chymotrypsin, while the killed organisms were rapidly digested. Gram-positive bacteria, on the other hand, were resistant whether living or dead. The findings are discussed.


AQUASAINS ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 647
Author(s):  
Esti Harpeni ◽  
Supono Supono ◽  
Dwi Risca Septiani

Isolate D2.2 is a bacterial isolate with 97% homology level with Bacillus sp. This isolate is a biocontrol bacterium capable of inhibiting the growth of Gram positive bacteria and Gram negative bacteria. The use of biocontrol bacteria is one solution of disease problem in cultivation organism. Prior to being applied to the field, D2.2 isolates need to go through a series of tests, one of which is growth kinetics testing under various environmental conditions, such as different degrees of pH and salinity. This is because environmental factors can affect the rapid growth of bacteria. The purpose of this study was to study the bacterial growth kinetics of D2.2 at different pH and salinity. The growth kinetics was observed by measuring optical density (OD) through a method of turbidimetry using a spectrophotometer at a wavelength of 625 nm to the stage of death. The results showed that the fastest growth rate was found at 20 ppt salinity with 0.179 h-1 and generation time of 5,588 hours. While in all pH treatments, generation time and growth rates achieved all treatments have the same pattern.


2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Herbert Gbejuade ◽  
Mohamed Elsakka ◽  
Lucy Cutler

To evaluate the sensitivity and specificity of Gram staining of synovial fluid aspirated from native joints suspected to be infected, we reviewed results of synovial fluid Gram stain and cultures. The sensitivity and specificity of the synovial Gram stain were then calculated. From the 1067 consecutive synovial fluid samples evaluated, 830 samples fulfilled the set criteria. From these 830 synovial fluid samples, organisms were detected by culture technique in only 100 samples; most of which were Gram-positive bacteria (78%). The other 22% comprised Gram-negative bacteria, Fungi and a mixture of growth. Of these, concomitant Gram stain test revealed sensitivity and specificity of 17.0% and 99.7% respectively. Our study demonstrates that the Gram stain technique has low sensitivity in detecting organisms in presumed native joint infections. Our findings demonstrate that the Gram stain test is an unreliable investigation in diagnosing native joint infections.


1975 ◽  
Vol 21 (5) ◽  
pp. 688-693 ◽  
Author(s):  
Charles Hagedorn ◽  
John G. Holt

Twenty-five gram-negative and 62 gram-positive bacterial cultures, of which 37 were arthrobacters, were tested, using a multipoint inoculation device, for responses on varying concentrations of 35 dyes. Both selective (growth vs. no growth) and differential (dye absorption) responses were obtained. It was possible to differentiate the arthrobacters from the other gram-positive bacteria tested as well as to distinguish separately each Arthrobacter -named strain. The results indicated that dyes have a greater potential for use in selective and differential media than has been presently realized; and the possibility of using dye-reactions as features in taxonomic schemes to differentiate rapidly many of the common genera of soil bacteria is discussed.


2020 ◽  
Vol 14 (6) ◽  
pp. 261-270 ◽  
Author(s):  
Atef El Jery ◽  
Mudassir Hasan ◽  
Md Mamoon Rashid ◽  
Mohammed Khaloofah Al Mesfer ◽  
Mohd Danish ◽  
...  

AbstractBackgroundThe composition and activities of essential oil of common sage from Saudi Arabia have not yet been reported.ObjectivesTo analyze the composition and antibacterial and antioxidant activities of essential oil from leaves of the common sage Salvia officinalis L. from Abha, Saudi Arabia.MethodsEssential oil was extracted from the leaves of S. officinalis by hydrodistillation, and its composition was analyzed using gas chromatography and mass spectrometry. Phenolics and flavonoids were determined using gallic acid and quercetin standards. Antioxidant activity was determined using a 2,2-diphenyl-1-picrylhydrazyl radical scavenging method. Activity against various gram-positive and gram-negative bacteria was determined by disk diffusion and microdilution.ResultsThe yield of essential oil was 3.24 ± 0.55% (w/dry weight). Major compounds identified were camphor (20.3%), 1,8-cineole (15.0%), α-thujone (14.9%), viridiflorol (9.9%), carvone (6.2%), and β-thujone (5.7%). Phenolic content was 134.3 ± 17.61 μg/mL and flavonoid content was 119.5 ± 18.75 μg/mL. Antioxidant IC50 was 970 ± 5.5 μg/mL. The highest gram-positive antibacterial activity was for Bacillus subtilis and the highest gram-negative activity was for Escherichia coli. Minimum inhibitory concentrations ranged from 62.2 ± 3.9 to 1398.1 ± 50.7 μg/mL for gram-positive bacteria and from 323.4 ± 69.5 to 968.4 ± 120.6 μg/mL for gram-negative bacteria. Minimum bactericidal concentrations ranged from 120.3 ± 7.6 to 1387.4 ± 161.8 μg/mL for gram-positive bacteria and from 386 ± 8.3 to 1225.2 ± 100.9 μg/mL for gram-negative bacteria.ConclusionsEssential oil of S. officinalis L. from Abha, Saudi Arabia, showed compositional, antioxidant, and antibacterial properties generally consistent with essential oil of S. officinalis L. from other locations as reported in the literature.


2008 ◽  
Vol 2 (1) ◽  
pp. 65-70
Author(s):  
Intesar Hussien Ali

The antibacterial effect of garlic (Allium sativum) extract was evaluated by in vitrostudy testing the growth of various Gram-Positive and Gram-Negative bacteria.The bactericidal activity of this extract was analyzed by serial dilution in tubes.This study, found that Gram-Negative and Gram-Positive bacteria susceptible tovery low garlic concentrations. On the other hand, Gram-Negative bacteria weremore susceptible than Gram-Positive bacteria, the minimal bactericidalconcentration of Gram-Negative bacteria was 2 mg ml-1 but minimal bactericidalconcentration of Gram-Positive bacteria was 4 mg ml- that means doubleinhibition concentration of Gram-negative bacteria. This study suggest that garlichave inhibition effect about Gram-Positive and Gram-Negative bacteria and garlicwas natural material found in Iraq and world wide with little side effect.


2007 ◽  
Vol 20 (3) ◽  
Author(s):  
B.K.M. DASS ◽  
M.N. VENUGOPAL ◽  
INDRANI KARUNASAGAR ◽  
IDDYA KARUNASAGAR

Biofilms are important biological structures formed on most submerged aquatic surfaces. They comprise a unique niche wherein a community of microorganisms co-exist. The study was undertaken to identify the bacterial flora associated with biofilms formed on the surface of larval rearing tanks in a prawn hatchery. Surface swabs of two randomly chosen larval rearing tanks in a hatchery were taken regularly throughout the hatchery cycle and the bacterial loads were estimated. The counts varied from 1.8x103 to 4.3x104 CFU.cm-2 in Tank I and 5.1x103 to 3.5x104 CFU.cm-2 in Tank II. No significant difference was observed between Tank I and Tank II in respect of biofilm bacterial count when enumerated (p<0.05). The common bacterial genera isolated in both tanks comprised gram-negative bacteria including Pseudomonas, Vibrio and Aeromonas. Bacillus and other non-spore formers were the predominant gram-positive bacteria isolated. Bacteria associated with biofilms are more resistant to antibiotics and water sanitizers generally used in tank water treatment. Biofilms can be a reservoir of pathogens and bacteria such as Pseudomonas, Aeromonas and Vibrio isolated from the biofilms in this study may be potential pathogens of prawn larvae in hatcheries.


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