scholarly journals Evidence of isosteric and allosteric nucleotide inhibition of citrate synthease from multiple-inhibition studies

1975 ◽  
Vol 151 (2) ◽  
pp. 455-458 ◽  
Author(s):  
S Harford ◽  
P D J Weitzman
Keyword(s):  
The Other ◽  
Allosteric Inhibition ◽  
Gram Positive ◽  
Acetyl Coa ◽  
Gram Negative ◽  
Allosteric Inhibitor ◽  
Other Hand ◽  
Bacterial Enzyme ◽  
Nucleotide Inhibition ◽  
Inhibition Studies

Citrate synthases from diverse organisms are inhibited by ATP and NADH. Evidence is presented, from multiple-inhibition studies on various citrate synthases, that ATP acts in all cases as an isosteric inhibitor at the acetyl-CoA site. On the other hand, NADH also acts isosterically with eukaryotic and Gram-positive bacterial citrate synthases, but behaves as an allosteric inhibitor specifically in the case of the Gram-negative bacterial enzyme. After desensitization to this allosteric inhibition, only the isosteric nucleotide inhibition, as found in other citrate syntheases, is observed.

Gut Flora in Autistic Children as Biomarker for Autism in Thi-Qar Province/Iraq

2020 ◽  
pp. 73-79
Keyword(s):  
Escherichia Coli ◽  
Enterococcus Faecalis ◽  
The Other ◽  
Bacterial Isolates ◽  
Autistic Children ◽  
Gram Positive ◽  
Gram Negative ◽  
Other Hand ◽  
Significant Difference ◽  
Gram Positive Cocci

This is the first study that investigated the microbial factor as biomarker in autistic children and discuss roles of this factor in the pathogenesis of autism. The participants in current study were 145 persons, only 50 sample of stool could collected (35 autistic children and 15 healthy children). Autistic children were attended to autism unit at Disabled Hospital in Thi-Qar province, Iraq during the period from January to November 2016. The results showed males (81%) more than female (19%) with ratio 4:1 and also results explain the age group of 3-5 years recorded the highest percentage (41.05%). Distribution of autistic children according to sibling showed six were brotherly with occurrence rate 6.3%. Stool samples were subjected to examination and culture. The total aerobic count of isolated bacteria was 140 isolates. Gram-negative isolates were identified by API Enterobacteriaceae system. The results were Escherichia coli, Enterobacter cloacae, Klebsiella pneumonia, Pseudomonas aeruginosa and Proteus mirabilis with percentage 38.5%, 19.23%, 11.53%,7.69%, and 3.84% respectively. On the other hand, gram positive cocci isolates included Enterococcus faecalis, Staphylococcus aureus and Staph. epidermidis with percentage 11.53%, 4.80% and 2.88% respectively. A significant difference (P≤0.05) was recorded between bacterial isolates. Quantity and quality of isolated bacteria (colony/g *104) were done. E.coli isolates were the highest count with 261*104 colony/g while, Staphylococci epidermidis were recorded the worse colony count with 30*104 colony/g. The quality results showed Escherichia coli the most common gram negative bacterial isolates (38.46%). On the other hand, the highest gram positive cocci isolates were included Enterococcus faecalis (11.53%), with significant difference (P≤0.05) between bacterial isolates. The ability of bacterial isolates to produce histidine decarboxylase was examined on Niven medium. The positive result include colonies with purple halo around them. Only 10 isolates (25%) from all isolates were produce histidine belong to E.coli. On other hand, result of parasite examination explain no parasite in all samples. From this study can conclusion the altered gut microflora may play an essential role in the pathogenesis of autism. Despite the accurate evidence, this etiological heterogeneity is still not recognized by autism researchers, and most studies fail to take it into account.

scholarly journals EFFECT OF PURIFIED ENZYMES ON VIRUSES AND GRAM-NEGATIVE BACTERIA

1936 ◽  
Vol 64 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Malcolm H. Merrill
Keyword(s):  
Proteolytic Enzymes ◽  
The Other ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Other Hand

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.

scholarly journals In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

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.

scholarly journals Morphological characterization of gram-positive and gram-negative bacteria from treated latex processing wastewater

2021 ◽  
Vol 1 (2) ◽  
pp. 32-36
Author(s):  
Farrah Aini Dahalan ◽  
Nor Azizah Parmin
Keyword(s):  
Oxygen Demand ◽  
Morphological Characterization ◽  
The Other ◽  
Morphological Properties ◽  
Morphological Observation ◽  
Gram Positive ◽  
Bacterial Colony ◽  
Gram Negative ◽  
Gram Staining

A preliminary morphological screening and isolation of bacterial colony from latex industrial wastewater was carried out. Bacteria colonies from latex processing wastewater were isolated from a local latex processing industry. It was found that 17 bacterial isolates had been purified grown on nutrient agar under 35˚C. The colonies were then purified and morphologically indicated via Gram staining and motility test. After morphological observation, it was identified that out of 17 isolates, 9 isolates were Gram positive and 8 isolates were Gram negative. There are 11 out of 17 colonies were rod-shaped bacterial colonies, while the other 6 colonies were cocci-shaped bacteria. There were 11 colonies of gliding bacteria, three colonies were non-motile bacteria and the other three colonies were flagellated bacteria. This study is only limited to morphological observation as the main aim of this study was to investigate the potential occurrence of viable growth in treated latex processing wastewater. The bacterial colonies were classified base on their morphological properties shown. This study has classified several genera such as Staphylococcus, Escherichia, Thiobacillus, Arthrobacter and other Genus. The growth curve of 17 isolates studied and the chemical oxygen demand were determined.

scholarly journals CHARACTERIZATION OF LEUKIN: AN ANTIBACTERIAL FACTOR FROM LEUCOCYTES ACTIVE AGAINST GRAM-POSITIVE PATHOGENS

1956 ◽  
Vol 104 (6) ◽  
pp. 829-845 ◽  
Author(s):  
Robert C. Skarnes ◽  
Dennis W. Watson
Keyword(s):  
Amino Acids ◽  
The Other ◽  
Polymorphonuclear Leucocytes ◽  
Natural Immunity ◽  
Gram Positive ◽  
Gram Negative ◽  
Heat Stable ◽  
Apparent Similarity ◽  
Antibacterial Factor

A method has been described for the preparation of a potent antibacterial factor from rabbit polymorphonuclear leucocytes. Upon characterization, the factor was found to possess many properties in common with basic proteins. The amino acid analysis revealed that it contained a relatively large amount of arginine (17 per cent) and small amounts of the other two basic amino acids. It has therefore been identified as a protamine or protamine derivative. The leucocyte factor was very active against all Gram-positive pathogens tested but exhibited little or no action against Gram-negative species. A possible explanation of this phenomenon has been discussed. The factor was very heat-stable at acid and neutral pH and its staphylococcidal activity was blocked by glutamyl polypeptide, hyaluronic acid, and desoxyribonudeic acid. Because of the apparent similarity of the product studied here to other poorly defined leucocyte factors which had been termed leukins in the early literature, it is suggested that the name leukin be retained for it. The possible significance of this leukin in natural immunity has been discussed.

scholarly journals In vitro and in vivo antibacterial efficacies of CFC-222, a new fluoroquinolone.

1997 ◽  
Vol 41 (10) ◽  
pp. 2209-2213 ◽  
Author(s):  
J H Kim ◽  
J A Kang ◽  
Y G Kim ◽  
J W Kim ◽  
J H Lee ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Protective Efficacy ◽  
Horse Serum ◽  
The Other ◽  
Infection Model ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

CFC-222 is a novel fluoroquinolone containing a C-7 bicyclic amine moiety with potent antibacterial activities against gram-positive, gram-negative, and anaerobic organisms. We compared the in vitro and in vivo activities of CFC-222 with those of ciprofloxacin, ofloxacin, and lomefloxacin. CFC-222 was more active than the other fluoroquinolones tested against gram-positive bacteria. CFC-222 was particularly active against Streptococcus pneumoniae (MIC at which 90% of isolates are inhibited [MIC90], 0.2 microg/ml), Staphylococcus aureus (MIC90, 0.2 microg/ml for ciprofloxacin-susceptible strains), and Enterococcus faecalis (MIC90, 0.39 microg/ml). Against Escherichia coli and other members of the family Enterobacteriaceae, CFC-222 was slightly less active than ciprofloxacin (MIC90s for E. coli, 0.1 and 0.025 microg/ml, respectively). The in vitro activity of CFC-222 was not influenced by inoculum size, medium composition, or the presence of horse serum. However, its activity was decreased significantly by a change in the pH of the medium from 7.0 to 6.0, as was the case for the other quinolones tested. The in vivo protective efficacy of CFC-222 by oral administration was greater than those of the other quinolones tested in a mouse model of intraperitoneally inoculated systemic infection caused by S. aureus. CFC-222 exhibited efficacy comparable to that of ciprofloxacin in the same model of infection caused by gram-negative organisms, such as E. coli and Klebsiella pneumoniae. In this infection model, CFC-222 was slightly less active than ciprofloxacin against Pseudomonas aeruginosa. These results suggest that CFC-222 may be a promising therapeutic agent in various bacterial infections.

scholarly journals THE ORGANISM ASSOCIATED WITH SPECIFIC INFECTIOUS CYSTITIS AND PYELONEPHRITIS OF COWS

1926 ◽  
Vol 44 (1) ◽  
pp. 11-20 ◽  
Author(s):  
F. S. Jones ◽  
Ralph B. Little
Keyword(s):  
Great Degree ◽  
The Other ◽  
Laboratory Animals ◽  
Cultural Characteristics ◽  
Gram Positive ◽  
General Morphology ◽  
Other Hand

A Gram-positive diphtheroid isolated from spontaneous cases of cystitis and pyelonephritis of cows on five farms has been studied. All the strains obtained were of the same general morphology. They possess similar cultural characteristics and to a great degree similar agglutination affinities. The organism is not pathogenic for the ordinary laboratory animals. It produces no toxin. Cows injected intravenously with broth cultures failed to develop the disease. On the other hand, small quantities of cultures introduced into the bladder by way of the urethra gave rise to a typical persistent cystitis. There is evidence for a transmission of the disease by contact infection, as when the same individual curries both normal and infected cows.

MORPHOLOGICAL AND PHYSIOLOGICAL GROUPS OF SOIL BACTERIA FROM THE ROOTS OF BARLEY AND OATS

1956 ◽  
Vol 2 (5) ◽  
pp. 473-481 ◽  
Author(s):  
H. DeL. King ◽  
R. H. Wallace
Keyword(s):  
Soil Bacteria ◽  
Sandy Loam ◽  
The Other ◽  
Physiological Characteristics ◽  
Gram Positive ◽  
Gram Negative ◽  
Rhizosphere Soils ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Percentage Incidence

Morphological and physiological characteristics were studied of more than 2400 stock-cultures of bacteria isolated from rhizosphere soils of barley and oats, and from control soils. Gram-positive rods were proportionately more numerous in control soils than in rhizosphere soils; this difference was greater with oats than with barley. The proportion of Gram-negative rods was greater in rhizosphere soils than in controls but not more so for one crop than the other. Gram-positive rods replaced a significant portion of Gram-negative rods in soils of the mature barley plants. The only significant increase in percentage incidence of physiological groups in rhizosphere soils was in regard to nitrate-reducing bacteria of the young oats plants. On the other hand there were significantly smaller percentages for starch-hydrolyzing bacteria and gelatin liquefiers in oats rhizospheres than in the controls. There were not any significant differences between rhizospheres and controls with regard to physiological groups from the barley plants. It is concluded that the proportional incidences of some physiological groups of soil bacteria are not greatly increased, but in some instances are decreased, by the presence of barley or oat roots growing in Chicot sandy loam.

scholarly journals MICROBIOLOGICAL SCREENING OF OTORRHOEA FROM PEOPLE COMING TO HOSPITAL IN MAHAJANGA

2020 ◽  
pp. 25-28
Author(s):  
Rivo RAKOTOMALALA ◽  
Patrick RANDRIANANDRAINA ◽  
Tsiriniaina RAMAVOSON ◽  
Fiacre RAMISARIMANANA ◽  
Ainamalala Catherine RAZAFINDRAKOTO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
The Other ◽  
Coagulase Negative Staphylococcus ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Ear Infections ◽  
Corynebacterium Sp ◽  
Gram Positive Cocci

In whole, 56 patients were included. Amidst identified microorganisms were fungus (4,7%) and bacteria (95,3%) to which Gram negative bacilli represented 72,1% (n=44), Gram positive cocci 6,4% (n=10), Gram positive bacilli 8,2% (n=5) and Gram negative cocci 3,3% (n=2). Among these bacterias, Pseudomonas aeruginosa and Proteus sp were predominant, with respectively 41% (n=25), 23% (n=14). However, three cases of S. aureus reported, six with negative coagulase Staphylococcus, one with Escherichia coli, one with Klebsiella sp, one with Haemophilus sp, two cases with Neisseria sp and four cases with Corynebacterium sp. Two types of cultures were noticed, one of them monomorphic (91,1%, n=51) and the other polymorphic (8,9%, n=5) to which 3 associations of P. aeruginosa-Proteus sp, 1 association of P. aeruginosa- coagulase negative Staphylococcus and 1 association of P. aeruginosa- E. coli. No resistance to ciprofloxacin was observed with Pseudomonas, Neisseria sp, Haemophilus, and enterobacteria except for E. coli. No resistance to rifampicin was observed with S. aureus. However, the sensitivity of S. aureus to ciprofloxacin decreased (one bacterium out of three). The use of rifampicin or fluoroquinolones should be based on the type of ear infections,

scholarly journals IN VITRO ANTIMICROBIAL ACTIVITY OF CARVACROL AGAINST SHRIMP PATHOGENS AND ITS USE AS FEED ADDITIVE FOR THE PACIFIC WHITE SHRIMP

2021 ◽  
Vol 47 ◽  
pp. e645
Author(s):  
Jaqueline da Rosa COELHO ◽  
Karolina Victória ROSA ◽  
Jamilly Sousa ROCHA ◽  
Norha Constanza Bolívar RAMÍREZ ◽  
Marcelo MARASCHIN ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Vibrio Harveyi ◽  
Pacific White Shrimp ◽  
The Other ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Vitro Effect

This study aimed to evaluate the in vitro effect of carvacrol on different microorganisms of importance in shrimp farming, as well as its in vivo effect on zootechnical, immunological and microbiological performance, as well as resistance, of Litopenaeus vannamei challenged with Vibrio parahaemolyticus. In particular, the antimicrobial activity of carvacrol was evaluated in vitro by analysis of the minimum inhibitory concentration (MIC) and by agar diffusion disc with Gram-negative and Gram-positive bacteria. The in vivo experiment was conducted using different concentrations of carvacrol (1, 3, 4 and 6 mg mL-1) added to shrimp feed, together with a control diet without carvacrol. After four weeks, zootechnical, immunological and microbiological parameters, as well as resistance, of animals challenged with V. parahaemolyticus were evaluated. The MIC of Vibrio alginolyticus and Vibrio harveyi was 0.078 mg mL-1, while for the other bacteria, it was 0.156 mg mL-1 of carvacrol. The greatest halos of inhibition were observed in V. parahaemolyticus and Vibrio harveyi with significant differences demonstrated for the other microorganisms, except Escherichia coli. The in vivo results showed no significant differences among treatments. In conclusion, the antimicrobial activity of carvacrol was confirmed with Gram-negative and Gram-positive bacteria, and it is suggested that its antimicrobial potential is more effective against Vibrio spp. However, the concentrations of carvacrol used in vivo did not affect the parameters evaluated.

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