6-Phospho-β-galactosidases of Gram-positive and 6-phospho-β-glucosidase B of Gram-negative bacteria: comparison of structure and function by kinetic and immunological methods and mutagenesis of the lacG gene of staphylococcus aureus

1993 ◽  
Vol 6 (8) ◽  
pp. 913-920 ◽  
Author(s):  
Ellen Witt ◽  
Rainer Frank ◽  
Wolfgang Hengstenberg
2014 ◽  
Vol 8 (3) ◽  
pp. 40-45
Author(s):  
Zina Hashem Shehab ◽  
Huda Suhail Abid ◽  
Sumaya Fadhil Hamad ◽  
Sara Haitham

The study was conducted to evaluate the inhibitory activity of methanol extract of Gardenia jasminoides leaves compared with leaf crude extracts for some organic solvents namely Methanol, Ethanol, Petroleum ether, Asetone and Chloroform on growth of some pathogenic bacteria and yeast, which included four gram positive isolates Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus cereus and gram negative isolates Escherichia coli, Salmonella typhi, Proteus vulgaris and Pseudomonas aeruginosa and some yeasts Candida albicans and Saccharomyces boulardii, by using well diffusion method. The inhibitory activity of extracts in the tested bacterial strains and yeasts was varied according to the type of extracting solvents and are tested microorganisms. The methanol callus extract which grown on Murashige and Skoog (MS) media by using (Naphthalen acitic acid) NAA and (Benzyle adenine) BA as growth regulator highly effective as compared to the other extracts as for inhibition of three gram positive bacteria and three gram negative bacteria,which include Staphylococcus aureus and, Proteus vulgaris, followed by acetone and ethanolic extracts which include two gram positive bacteria and two gram negative bacteria. All extracts had highly effect in growth of Candida albicans while all crude extracts didn’t show any sensitivity against Saccharomyces boulardii, and when we’d done (High Performance Liquid Chromatography) HPLC test for detection of some active compound we found Quinic acid, Iridiods glycosides and Crocin which its rate in fresh callus was higher than fresh leaves.


2012 ◽  
Vol 7 (5) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Alexis Peña ◽  
Luis Rojas ◽  
Rosa Aparicio ◽  
Libia Alarcón ◽  
José Gregorio Baptista ◽  
...  

The essential oil of the leaves of Espeletia nana Cuatrec, obtained by hydrodistillation, was analyzed by GC-MS, which allowed the identification of 24 components, which made up 99.9% of the oil. The most abundant compounds were α-pinene (38.1%), β-pinene (17.2%), myrcene (15.0%), spathulenol (4.2%), bicyclogermacrene (4.0%), α-zingiberene (4.0%), and γhimachalene (3.7%). Antibacterial activity was tested against Gram-positive and Gram-negative bacteria using the agar disk diffusion method. Activity was observed only against Gram-positive bacteria. MIC values were determined for Staphylococcus aureus ATCC 25923(200 μg/mL) and Enterococcus faecalis ATCC 29212 (600 μg/mL).


1988 ◽  
Vol 55 (4) ◽  
pp. 597-602 ◽  
Author(s):  
Lydia Bautista ◽  
Rohan G. Kroll

SummaryEffects of the addition of a proteinase (Neutrase 1–5S) and a peptidase (aminopeptidase DP-102) as agents for accelerating the ripening of Cheddar cheese on the survival of some non-starter bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coliand aSalmonellasp.) were studied throughout a 4-month ripening period. The enzymes were found to have no significant effect on the survival of the Gram-positive bacteria but some significant effects were observed, at some stages of the ripening period, with the Gram-negative bacteria in that lower levels were recovered from cheeses treated with the enzyme system.


2011 ◽  
Vol 60 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Svetlana A. Ermolaeva ◽  
Alexander F. Varfolomeev ◽  
Marina Yu. Chernukha ◽  
Dmitry S. Yurov ◽  
Mikhail M. Vasiliev ◽  
...  

Non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. The purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. Overall, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, Burkholderia cenocepacia and Escherichia coli, there were no survivors among the initial 105 c.f.u. after a 5 min plasma treatment. The susceptibility of Gram-positive bacteria was species- and strain-specific. Streptococcus pyogenes was the most resistant with 17 % survival of the initial 105 c.f.u. after a 5 min plasma treatment. Staphylococcus aureus had a strain-dependent resistance with 0 and 10 % survival from 105 c.f.u. of the Sa 78 and ATCC 6538 strains, respectively. Staphylococcus epidermidis and Enterococcus faecium had medium resistance. Non-ionized argon gas was not bactericidal. Biofilms partly protected bacteria, with the efficiency of protection dependent on biofilm thickness. Bacteria in deeper biofilm layers survived better after the plasma treatment. A rat model of a superficial slash wound infected with P. aeruginosa and the plasma-sensitive Staphylococcus aureus strain Sa 78 was used to assess the efficiency of argon plasma treatment. A 10 min treatment significantly reduced bacterial loads on the wound surface. A 5-day course of daily plasma treatments eliminated P. aeruginosa from the plasma-treated animals 2 days earlier than from the control ones. A statistically significant increase in the rate of wound closure was observed in plasma-treated animals after the third day of the course. Wound healing in plasma-treated animals slowed down after the course had been completed. Overall, the results show considerable potential for non-thermal argon plasma in eliminating pathogenic bacteria from biofilms and wound surfaces.


1952 ◽  
Vol 30 (6) ◽  
pp. 674-681 ◽  
Author(s):  
P. H. H. Gray ◽  
L. J. Taylor

Laurylamine saccharinate has been tested for its bacteriostatic powers against 30 species of bacteria, namely, 6 Gram-positive micrococci, 12 Gram-positive and 12 Gram-negative 'rods'. The compound was used in concentrations of 0.0005, 0.001, and 0.005% in plain broth, broth with glycerol, and broth with glycerol and skim milk, these adjuncts representing progressively increasing amounts of organic matter. The Gram-negative bacteria were the most resistant. The bacteriostatic action of the laurylamine was progressively reduced by the organic matter. Staphylococcus aureus was not killed by 0.005% laurylamine in the medium containing skim milk. Media containing phenol were used as a measure of comparison, and similar effects of organic matter were observed. Agar also reduced the bacteriostatic power of the laurylamine.


Author(s):  
Abigail R. Sopia ◽  
Pushpa Innocent D. Joseph ◽  
M. Kalyani ◽  
B. Ananthi ◽  
Suresh Dhanaraj ◽  
...  

Genital infections and subsequent vaginosis diagnosed through high vaginal swab in women is caused due to fungi or bacteria. The presented study focused on determining the types, numbers and antibacterial susceptibility pattern of aerobic bacteria causing vaginosis in 147 female patients attending infertility centre in Chennai, Tamil Nadu, India. Candida spp. caused 17% of infections with 15.7% of vaginosis caused by E.coli, Klebsiella spp., Acinetobacter spp., Citrobacter spp. and Gram positive cocci – Methicillin Sensitive Staphylococcus aureus (MSSA), Coagulase Negative Staphylococci(CONS), Staphylococcus aureus and Enterococcus spp. causing 12.9% of vaginitis in the study population. A total of 20 different antibiotics – cell wall inhibitors, protein synthesis inhibitors and nucleic acid synthesis inhibitors; were tested to determine the response of bacterial isolates by Kirby-Bauer disc diffusion method. The study result determined that the most effective drug for treating Gram positive bacterial vaginitis as per CLSI guidelines based on susceptibility pattern as: Linezolid(100%), Gentamycin(91.6%), Amikacin(87.5%),Erythromycin(79.2%), Co-Trimoxazole(72.2%), Ciprofloxacin(65.6%) and least Chloramphenicol(44.3%). High level gentamycin(83.3%) was found to be effective in treating Enterococci. The descending order of susceptibility of Gram negative aerobacteria causing vaginitis as per CLSI guidelines are: Amikacin(87.5%), Gentamycin(82.5%), Cefoperazone sulbactam (76.3%), Ciprofloxacin(68.5%), Ceftazidime(62.5%) and least Amoxyclav(25%).All Gram negative bacteria tested were susceptible to– Imipenem and Meropenem as well as Chloramphenicol. Ceftriaxone (87.5%) and Nitrofurantoin(72.3%) among other antibiotics was effective against Gram negative bacteria while all Enterobacteriaceae members were found to be resistant to tetracycline.


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