scholarly journals Antibacterial effects of commercially available phosphates on selected microorganisms

Author(s):  
Leona Buňková ◽  
Pavel Pleva ◽  
František Buňka ◽  
Pavel Valášek ◽  
Stanislav Kráčmar

In the food industry, phosphates, polyphosphates and their salts are used, for example, as emul­si­fying agents in the production of processed cheese. The inhibitory effects of three commercially avai­la­ble phosphates and polyphosphates differing in their chain length (690, S9 and HBS) were tested on a set of 15 gram-positive or gram-negative CCM (Czech Collection of Microorganisms) strains and on 12 bacterial strains isolated from processed cheeses. Five different concentrations of each phosphate were chosen (0.1, 0.2, 0.3, 0.4 and 0.5% w/v) in order to observe the inhibitory effects of the phosphate salts on the growth of the microorganisms tested. Sensitivity of the individual bacterial strains to phosphates was observed of a liquid cultivation medium which was supplemented with applied salts. Subsequently, the growth in cells was determined by measuring optical density at a wavelength of 600 nm. According to the results, 690 and S9 phosphates, containing mainly orthophosphates, diphosphates (pyrophosphates) and short-chain polyphosphates, do not have a significant inhibitory effect on the growth of the tested bacteria. Significant inhibitory effects were observed only in HBS salt (a mixture of long-chain polyphosphates), which showed antibacterial effects on all gram-positive bacteria tested (both the CCM strains and those isolated from processed cheeses). The antibacterial effect of phosphates on gram-positive microorganisms is growing with the increasing length of the polyphosphate chain. This study has not proved a significant effect of the phosphates tested on the growth of gram-negative bacteria used.

1999 ◽  
Vol 62 (9) ◽  
pp. 1017-1023 ◽  
Author(s):  
MARILENA MARINO ◽  
CARLA BERSANI ◽  
GIUSEPPE COMI

The essential oils obtained from Thymus vulgaris L. harvested at four ontogenetic stages were evaluated for their biological activity and chemical composition. The thyme essential oils were tested for their inhibitory effects against nine strains of gram-negative bacteria and six strains of gram-positive bacteria. The bioimpedance method was chosen for studying the antibacterial activity of the essential oils and the parameter chosen for defining and quantifying the antibacterial activity of the essential oils was the detection time. The plate counting technique was used to study the inhibitory effect by direct contact. All the thyme essential oils examined had a significant bacteriostatic activity against the microorganisms tested. This activity was more marked against the gram-positive bacteria. The oil from thyme in full flower was the most effective at stopping the growth of the microbial species examined. The oils tested were also shown to have good antibacterial activity by direct contact, which appeared to be more marked against the gram-negative bacteria. Only a few of the species were capable of recovering at least 50% of their metabolic function after contact with the inhibitor, while most of the strains were shown to have been inactivated almost completely. Escherichia coli O157:H7 was the most sensitive species, given that after contact with even the lowest concentration of oil cells could not be recovered.


2019 ◽  
Vol 6 (1) ◽  
pp. 63-72
Author(s):  
Abdelali Merah ◽  
Abdenabi Abidi ◽  
Hana Merad ◽  
Noureddine Gherraf ◽  
Mostepha Iezid ◽  
...  

Abstract Interest in nanomaterials, especially metal oxides, in the fight against resistant and constantly changing bacterial strains, is more and more expressed. Their very high reactivity, resulting from their large surface area, promoted them to the rank of potential successors of antibiotics. Our work consisted of the synthesis of zinc oxide (ZnO) and copper oxide (CuO) in the nanoparticle state and the study of their bactericidal effect on various Gram-negative and Gram-positive bacterial strains. The nanoparticles of metal oxides have been synthesized by sol-gel method. Qualitative analysis and characterization by UV / Visible and infrared spectrophotometry and X-ray diffraction confirmed that the synthetic products are crystalline. The application of the Scherrer equation allows to determine the size of the two metal oxides, namely: 76.94 nm for ZnO and 24.86 nm for CuO. The bactericidal effect of ZnO and CuO nanoparticles was tested on Gram-positive bacteria (Staphylococcus aureus, Staphylococcus hominis, Staphylococcus haemolyticus, Enterococcus facials) and Gram-negative bacteria (Escherichia coli, Schigella, Klepsiella pneumoniae and Pseudomonas aeruginosa). The results indicate that the tested metal oxides nanoparticles have an effect that varies depending on bacterial species. Indeed, Gram-positive bacteria show greater sensitivity to ZnO nanoparticles whereas Gram-negative bacteria are more sensitive to CuO nanoparticles.


2010 ◽  
Vol 34 (1) ◽  
pp. 201-207
Author(s):  
Omar J. Al saree

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


2011 ◽  
Vol 46 (1) ◽  
pp. 105-110
Author(s):  
M Ur Rahman ◽  
S Gul ◽  
EA Odhano ◽  
Ir Hafeez ◽  
RB Tareen

The extracts of Zatoria multiflora Boiss were evaluated for prospective antibacterial activity against gram negative and gram positive bacteria. Cefoperazone is used as antibacterial reference drug. The activity of ethanol and methanol extract varied from organism to organism. The inhibitory effect of both the extracts and their 50/50 combination was more pronounced against gram positive bacteria. The MIC and MBC values were in the range of 1.718-6.25 and 2.832-6.25 mg/ml respectively. Significant (p=0.05) synergistic effect of combination of EtOH and MeOH extracts was recorded against Staphylococcus aureus ATCC 29213, Staphylococcus aureus ATCC 25923 while additive effect against rest of the bacterial strains. The present studies provide evidences for presence of antibacterial elements in alcoholic extracts and recommends for more exploration for it use against bacterial diseases. Key words: Extracts; Zatoria multiflora Boiss; Antibacterial; MIC; MBC; Synergistic. DOI: http://dx.doi.org/10.3329/bjsir.v46i1.3652 Bangladesh J. Sci. Ind. Res. 46(1), 105-110, 2011


Author(s):  
Shipra Baluja ◽  
Sumitra Chanda

Some Schiff bases of pyrazole and 4-amino antipyrine have been synthesized. The antibacterial screening of these synthesized compounds was done in dimethyl formamide against four Gram positive bacteria viz.Bacillus cereus, Staphylococcus aureus, Staphylococcus epidermidids and Micrococcus luteus, and three Gram negative bacteria viz. Proteus mirabilis, Escherichia coli and Klebsiella aerogenes. It is observed that in comparison to Schiff bases of 4-amino antipyrine, pyrazole Schiff bases are better for inhibition for these selected Gram positive and Gram negative bacterial strains.


2020 ◽  
Vol 9 (1) ◽  
pp. 941-944

Our present investigation aims to test the antibacterial action of Scheonoplectus triqueter (L) palla against the gram negative bacteria i.e. Escherichia coli and gram positive bacteria i.e staphylococcus aureus. The crude extract is taken in ethanol which is then fractionated into a different fraction in n-hexane, ethyl acetate, di-chloro methane (DCM) and water.The fractions are then separately applied to E.coli and s.aureus bacterial strains. Ampicillin (10 micro gram), Clindamycin (2 microgram) and Kanamycin sulfate (30 microgram) are used as a positive control while di-methyl sulfoxide (DMSO) is used as negative control. The result of antibacterial activity of Scheonoplectus triqueter (L) palla revealed to us that n-hexane section of the crude extractdisplayed relatively highest activity for E.coli (gram negative bacteria) and ethyl acetate fraction displayed relatively high activity for S.aureus (gram positive bacteria).


2021 ◽  
Author(s):  
Xuemei Li ◽  
Zhipeng Du ◽  
Ziwei Tang ◽  
Qin Wen ◽  
Qingfeng Cheng ◽  
...  

Abstract Background: When a diabetic foot ulcer (DFU) is complicated by necrotizing fasciitis (DNF), this may increase the risk for amputation and mortality, making DNF treatment more complicated, and may eventually lead to amputation and mortality. DNF treatment must include the appropriate antibiotic intervention. However, studies on the distribution and drug sensitivity of pathogenic bacteria in DNF patients remain lacking. This study investigated the distribution and susceptibility of pathogenic bacteria in DNF patients, and provides empirical antibacterial guidance for the clinic.Methods: In a single diabetic foot center, the results from microbial cultures and drug susceptibility tests of patients with DNF from October 2013 to December 2020 were collected and analyzed.Results: A total of 101 DNF patients were included in this study, of whom 94 had positive culture test results. A total of 124 pathogens were cultured, including 76 Gram-positive bacterial strains, 42 Gram-negative bacterial strains, and six fungal strains. Polymicrobial infections accounted for 26.7% and monomicrobial infections accounted for 66.3%. Staphylococcus aureus was the most common bacterium isolated, followed by Enterococcus faecalis and Streptococcus agalactiae. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Proteus mirabilis were the most common Gram-negative bacteria. Thirty-five strains of multi-drug resistant (MDR) bacteria were isolated, representing 28.2% of the total isolates. Gram-positive bacteria were more sensitive to levofloxacin, moxifloxacin, vancomycin, teicoplanin, tigecycline, and linezolid, while Gram-negative bacteria were more sensitive to amikacin, piperacillin/tazobactam, cefoperazone/sulbactam, ceftazidime, cefepime, imipenem, and meropenem. Conclusions: Gram-positive bacteria were the main bacteria isolated from DNF patients. The bacterial composition, the proportion of MDR bacteria among the pathogens, and high risk for amputation should be fully considered in the initial empirical medication, and broad-spectrum antibacterials are recommended.


1973 ◽  
Vol 19 (11) ◽  
pp. 1401-1405
Author(s):  
Nachman Garber ◽  
Batia Lupowitz-Donenfeld

The effects of L-thyroxine, D-thyroxine, and 3,5,3′-triiodothyronine on the growth of several Gram-positive and Gram-negative bacteria were examined. The first two compounds, at a concentration of 7.7 × 10−5 M, were found to have a considerable inhibitory effect while 3,5,3′-triiodothyronine had a very weak effect on the growth of the Gram-positive bacteria examined. The growth of the Gram-negative bacteria was not inhibited under the same conditions.Potassium iodide, at the same concentration, was not inhibitory. Release of free iodine from the thyroxine preparation was also excluded as contributing to the thyroxine effect because it was shown to be less toxic than thyroxine for Bacillus cereus 569 and to exhibit a similar inhibitory effect on Gram-positive and Gram-negative bacteria.The inhibition of Gram-positive bacteria by L-thyroxine was reduced by cations such as Mn2+, Fe2+, and Ca2+. However, the hormones were more potent in their effect compared to EDTA in the same molar concentration and the inhibition exerted by them was not so easily abolished by the divalent cations as it was in the case of EDTA. Although chelation could contribute to the inhibition of the bacteria by the iodinated hormones, it seems that it is not the only factor involved.


1989 ◽  
Vol 52 (1) ◽  
pp. 49-50 ◽  
Author(s):  
CARLOS M. LLABRÉS ◽  
BONNIE E. ROSE

Seven different brands of cellulose sponges and one polyurethane variety were evaluated for inhibitory properties on twelve strains of gram positive and gram negative bacteria. Sponges were cut in 13 mm or 17 mm discs, autoclaved and aseptically placed on inoculated Tryptic Soy agar plates. The inhibitory effects of sterile sponges, unrinsed, and rinsed in distilled water, were measured. The zone of inhibition values were based on the average of the diameters of the clear zones on the inoculated plates. Polyurethane and EXPANDING CELLULOSE SPONGES were the only varieties which did not exhibit antimicrobial properties with any of the selected bacterial strains. A thorough rinsing procedure was often insufficient to remove the inhibitory agents from the sponges. Listeria monocytogenes strain Scott A and Staphylococcus aureus, both gram positive, were strongly inhibited.


Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara

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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