scholarly journals Marine Alkaloid 2,2-Bis(6-bromo-3-indolyl) Ethylamine and Its Synthetic Derivatives Inhibit Microbial Biofilms Formation and Disaggregate Developed Biofilms

2019 ◽  
Vol 7 (2) ◽  
pp. 28 ◽  
Author(s):  
Raffaella Campana ◽  
Gianfranco Favi ◽  
Wally Baffone ◽  
Simone Lucarini
Keyword(s):  
Antimicrobial Activity ◽  
Plate Count ◽  
Side Chain ◽  
Bacterial Populations ◽  
E Coli ◽  
Microbial Biofilms ◽  
Marine Alkaloid ◽  
Natural Alkaloid ◽  
Bisindole Alkaloid ◽  
Synthetic Derivatives

The antimicrobial activity of the marine bisindole alkaloid 2,2-bis(6-bromo-3-indolyl) ethylamine (1) and related synthetic analogues (compounds 2–8) against target microorganisms was investigated by Minimum Inhibitory Concentration (MIC) determination. Compound 1 showed the greatest antimicrobial activity with the lowest MIC (8 mg/L) against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, while the derivatives exhibited higher MICs values (from 16 to 128 mg/L). Compounds 1, 3, 4, and 8, the most active ones, were then tested against E. coli, S. aureus, K. pneumoniae, and Candida albicans during biofilms formation as well as on 24 h developed biofilms. The natural alkaloid 1 inhibited the biofilm formation of all the tested microorganisms up to 82.2% and disaggregated biofilms of E. coli, S. aureus, K. pneumoniae, and C. albicans after 30 min of contact, as assessed by viable plate count and crystal violet (CV) staining (optical density at 570 nm). Synthetic derivatives 3, 4, and 8 displayed anti-biofilm activity toward individual bacterial populations. This study highlights the potential of marine bisindole alkaloid 1 as anti-biofilm agent and shows, through a preliminary structure activity relationship (SAR), the importance of halogens and ethylamine side chain for the antimicrobial and antibiofilm activities of this bisindole series.

Microbiological Status of Fresh Beef Cuts

2006 ◽  
Vol 69 (6) ◽  
pp. 1456-1459 ◽  
Author(s):  
J. D. STOPFORTH ◽  
M. LOPES ◽  
J. E. SHULTZ ◽  
R. R. MIKSCH ◽  
M. SAMADPOUR
Keyword(s):  
Total Coliform ◽  
Incidence Rates ◽  
Microbial Populations ◽  
Plate Count ◽  
Bacterial Populations ◽  
E Coli ◽  
Coliform Count ◽  
Processing Plants ◽  
Aerobic Plate Count ◽  
Whole Muscle

Fresh beef samples (n = 1,022) obtained from two processing plants in the Midwest (July to December 2003) were analyzed for levels of microbial populations (total aerobic plate count, total coliform count, and Escherichia coli count) and for the presence or absence of E. coli O157:H7 and Salmonella. A fresh beef cut sample was a 360-g composite of 6-g portions excised from the surface of 60 individual representative cuts in a production lot. Samples of fresh beef cuts yielded levels of 4.0 to 6.2, 1.1 to 1.8, and 0.8 to 1.0 log CFU/g for total aerobic plate count, total coliform count, and E. coli count, respectively. There did not appear to be substantial differences or obvious trends in bacterial populations on different cuts. These data may be useful in establishing a baseline or a benchmark of microbiological levels of contamination of beef cuts. Mean incidence rates of E. coli O157:H7 and Salmonella on raw beef cuts were 0.3 and 2.2%, respectively. Of the 1,022 samples analyzed, cuts testing positive for E. coli O157:H7 included top sirloin butt (0.9%) and butt, ball tip (2.1%) and for Salmonella included short loins (3.4%), strip loins (9.6%), rib eye roll (0.8%), shoulder clod (3.4%), and clod, top blade (1.8%). These data provide evidence of noticeable incidence of pathogens on whole muscle beef and raise the importance of such contamination on product that may be mechanically tenderized. Levels of total aerobic plate count, total coliform count, and E. coli count did not (P ≥ 0.05) appear to be associated with the presence of E. coli O157:H7 and Salmonella on fresh beef cuts. E. O157:H7 was exclusively isolated from cuts derived from the sirloin area of the carcass. Salmonella was exclusively isolated from cuts derived from the chuck, rib, and loin areas of the carcass. Results of this study suggest that contamination of beef cuts may be influenced by the region of the carcass from which they are derived.

Titanium nanoparticles phytosynthesized from Eichhornia crassipes leaf extract and their antimicrobial activity.

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3293-3299
Author(s):  
Monserrat Velázquez-Hernández ◽  
Pablo Schabes-Retchkiman ◽  
Sonia Martínez-Gallegos ◽  
V. Albiter
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Activity ◽  
Eichhornia Crassipes ◽  
Leaf Extract ◽  
Plate Count ◽  
Tem Analysis ◽  
E Coli ◽  
Solid Agar ◽  
Bacteriological Test ◽  
Titanium Nanoparticles

AbstractIn this study, we reported an environmentally friendly technique for the synthesis of titanium nanoparticles using Eichhornia crassipes leaf extract as a non-toxic reducing agent and efficient stabilizer. Also the antimicrobial activity TiNPs against E. coli. Bacteriological test were performed on solid agar plates with different concentrations of TiNPs. On the other hand TiNPs were characterized by UV-visible spectroscopy, EDS (Dispersive Energy X-ray Spectroscopy), SEM (Scanning Electron Microscopy), and TEM (Transmission Electron Microscopy). It was found that TiNPs exhibit high crystallinity whit rutile titania structure. TEM analysis shows the nanoparticle size in the range from 22 to 44 nm, antimicrobial study was performed by plate count technique witch showed >99% mortality for E. coli bacteria studied after 24 h of incubation.

The Effectiveness of Triclosan-Incorporated Plastic against Bacteria on Beef Surfaces†

1999 ◽  
Vol 62 (5) ◽  
pp. 474-479 ◽  
Author(s):  
CATHERINE N. CUTTER
Keyword(s):  
Antimicrobial Activity ◽  
Salmonella Typhimurium ◽  
Shigella Flexneri ◽  
Personal Hygiene ◽  
Slight Reduction ◽  
Bacterial Populations ◽  
E Coli ◽  
Initial Application ◽  
C Storage ◽  
Packaged Beef

Triclosan is a nonionic, broad-spectrum, antimicrobial agent that has been incorporated into a variety of personal hygiene products, including hand soaps, deodorants, shower gels, mouthwashes, and toothpastes. In this study, plastic containing 1,500 ppm of triclosan was evaluated in plate overlay assays and meat experiments as a means of reducing populations of bacteria. Plate overlay assays indicated that the triclosan-incorporated plastic (TIP) inhibited the following organisms: Brochothrix thermosphacta ATCC 11509, Salmonella Typhimurium ATCC 14028, Staphylococcus aureus ATCC 12598, Bacillus subtilis ATCC 6051, Shigella flexneri ATCC 12022, Escherichia coli ATCC 25922, and several strains of E. coli O157:H7. In meat experiment 1, irradiated, lean beef surfaces inoculated with B. thermosphacta, Salmonella Typhimurium, E. coli O157:H7, or B. subtilis were covered with TIP, vacuum packaged, and stored for 24 h at 4°C. Of the organisms tested, only populations of B. thermosphacta were slightly reduced. In meat experiment 2, prerigor beef surfaces were inoculated with E. coli O157: H7, Salmonella Typhimurium, or B. thermosphacta incubated at 4°C for 24 h, wrapped in TIP or control plastic, vacuum packaged, and stored at 4°C for up to 14 days. There was a slight reduction in the population of the organisms after initial application with TIP. However, bacterial populations following long-term, refrigerated (4°C), vacuum-packaged storage up to 14 days were not statistically (P≤ 0.05) or numerically different than controls. In meat experiment 3, even TIP-wrapped, vacuum-packaged beef samples that were temperature abused at 12°C did not exhibit significant (P ≤ 0.05) or sustainable reductions after 14 days of 4°C storage. Another study indicated that populations of E. coli O157:H7 or B. thermosphacta added directly to TIP were not affected after 2 h of refrigerated storage or that the antimicrobial activity could be extracted from the plastic. Additional experiments suggest that presence of fatty acids or adipose may diminish the antimicrobial activity of TIP on meat surfaces. This study demonstrates that while antimicrobial activity is detected against bacterial cultures in antimicrobial plate assays, plastic containing 1,500 ppm of triclosan does not effectively reduce bacterial populations on refrigerated, vacuum-packaged meat surfaces.

scholarly journals Antimicrobial, Antiparasitic and Cytotoxic Spermine Alkaloids from Albizia Schimperiana

2009 ◽  
Vol 4 (6) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Volodymyr Samoylenko ◽  
Melissa R. Jacob ◽  
Shabana I. Khan ◽  
Jianping Zhao ◽  
Babu L. Tekwani ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimalarial Activity ◽  
Human Cancer ◽  
Vero Cells ◽  
2D Nmr ◽  
Side Chain ◽  
Parasitic Infections ◽  
Human Cancer Cell Lines ◽  
E Coli

Albizia schimperiana Oliv. (Leguminosae) is a tree distributed in the highland of Kenya, where it is used as a traditional medicine for the treatment of bacterial and parasitic infections, notably pneumonia and malaria, respectively. Bioassay guided isolation of the CH2Cl2–MeOH 1:1/ MeOH-H2O 9:1 (mixed) extract of A. schimperiana afforded the new bioactive macrocyclic spermine alkaloid, namely 5, 14-dimethylbudmunchiamine L1 (1) and three known budmunchiamine analogs 2-4. The structures of the compounds 1-4 were determined by 1D and 2D NMR data, including COSY, HMQC, and HMBC experiments, and ESI-HRMS. Compounds 1 and 3 exhibited significant in vitro antimicrobial activity against a panel of microorganisms, including C. neoformans, methicillin-resistant S. aureus, E. coli, M. intracellulare, and A. fumigatus. In addition, they demonstrated strong in vitro antimalarial activities against chloroquine-susceptible (D6) and -resistant (W2) strains of Plasmodium falciparum with IC50s ranging from 120-270 ng/mL. Compounds 1-4 were also evaluated for cytotoxic activity against selected human cancer cell lines and mammalian kidney fibroblasts (VERO cells). It was observed that hydroxyl substitution of the side chain of the budmunchiamines dramatically reduced the cytotoxicity and antimicrobial activity of the alkaloids 2 and 4 without decreasing antimalarial activity.

Microbial Decontamination of Beef and Sheep Carcasses by Steam, Hot Water Spray Washes, and a Steam-Vacuum Sanitizer

1996 ◽  
Vol 59 (2) ◽  
pp. 127-135 ◽  
Author(s):  
WARREN J. DORSA ◽  
CATHERINE N. CUTTER ◽  
GREGORY R. SIRAGUSA ◽  
MOHAMMAD KOOHMARAIE
Keyword(s):  
Hot Water ◽  
Plate Count ◽  
Water Spray ◽  
Bacterial Populations ◽  
E Coli ◽  
Beef Carcasses ◽  
Aerobic Plate Count ◽  
Contamination Levels ◽  
Initial Contamination ◽  
Temperature Water

Three separate studies were conducted to determine the effectiveness of various temperature water spray washes (Wt), wash and steam combinations (WtS), and vacuum and wash combinations (VWt) for reducing fecal bacteria on sheep and beef carcasses. Wt of 15.6, 54.4, and 82.2°C were administered to sheep carcasses contaminated with feces, using a hand-held spray nozzle. Initial carcass bacterial populations of approximately 2.5, 4, and 6 log CFU/cm2 were subjected to all wash combinations. W82.2 and W82.2S reduced 6 log CFU/cm2 bacterial populations as much as 4.0 log cycles. When carcasses were subjected to WtS and W82.2, the initial contamination levels (4 and 6 log CFU/cm2) had little effect on final bacterial levels (2.7 to 3.3 log CFU/cm2). However, uninoculated carcasses with initial bacterial populations of 2.5 log CFU/cm2 experienced a 1.5-log-cycle reduction when subjected to WtS and W82.2. It is possible that hydration of a carcass before and during interventions affords some protection to bacteria. The next study used a commercial carcass washer to apply a hot water (72°C), low pressure (20 psi) wash in combination with a high pressure (125 psi), warm water (30°C) wash (W72/30). Reductions on beef of 2.7, 3.3, and 3.4 log cycles for aerobic plate count (APC), coliforms, and E. coli populations, respectively, were observed. When a commercial steam-vacuum was used in conjunction with W72/30, reductions of 3.1, 4.2, and 4.3 log cycles for APC, coliforms, and E. coli populations, respectively, were achieved. Implementation of these interventions could reduce the amount of trimming needed on carcass-processing lines and would increase the microbial safety of beef carcasses.

In-Plant Evaluation of a Lactic Acid Treatment for Reduction of Bacteria on Chilled Beef Carcasses†

2001 ◽  
Vol 64 (5) ◽  
pp. 738-740 ◽  
Author(s):  
A. CASTILLO ◽  
L. M. LUCIA ◽  
I. MERCADO ◽  
G. R. ACUFF
Keyword(s):  
Lactic Acid ◽  
Acid Treatment ◽  
Surface Region ◽  
Total Coliform ◽  
Hot Water ◽  
Plate Count ◽  
Bacterial Populations ◽  
E Coli ◽  
Time Of Application ◽  
Beef Carcasses

The effectiveness of a lactic acid treatment consisting of spraying a 4% l-lactic acid solution (55°C at source) on chilled beef carcasses to reduce bacterial populations was tested in a commercial slaughter environment. All carcasses had been treated with a proprietary decontamination treatment composed of a hot water spray followed by a lactic acid spray prior to chilling. Bacterial groups used to indicate reductions included aerobic plate count (APC), total coliform count, and Escherichia coli count, and samples were examined from the brisket, the clod, and the neck regions of 40 untreated and 40 treated carcass sides. Depending on the carcass surface region, APCs were reduced by 3.0 to 3.3 log cycles. Log coliform and E. coli counts were consistently reduced to undetectable levels. The small reductions observed for coliforms are attributable to counts on untreated carcasses already being near the lower detection limit of the counting method. The percentage of samples with detectable numbers of coliforms (positive samples) on untreated carcasses ranged from 52.5 to 92.5%, while 0.0% of the samples collected from treated carcasses contained detectable coliforms. Percent E. coli-positive samples ranged from 7.5 to 30.0% on untreated carcasses and 0.0% after treatment of carcass sides. These results indicate that a hot lactic acid spray with increased concentration and time of application may be effectively implemented for an additional decontamination treatment of chilled beef carcasses prior to fabrication.

scholarly journals Conventional versus the petrifilm method for the enumeration of different types of bacteria

1969 ◽  
Vol 73 (3) ◽  
pp. 183-187
Author(s):  
Fred Fernández-Coll ◽  
Luis Silva-Negrón
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Plate Count ◽  
Bacterial Populations ◽  
E Coli ◽  
Different Types ◽  
Plate Counts ◽  
Conventional Plate ◽  
Aerobic Plate Count

Performance of Petrifilm VRB and SM plates to enumerate different types of bacterial populations was evaluated. A total of 100 Petrifilms and 100 regular Petri plates were tested with each of 3 different bacterial populations in 4 experiments. The Petrifilm system was superior to the conventional pour plate methods, or at least not statistically different, in enumerating Escherichia coli (coliform) and a mixture of E. coli, Staphylococcus aureus and Serratia marcescens (total aerobic plate count). The Petrifilm method was superior to conventional plate counts in enumerating Pseudomonas aeruginosa (psychrotrophic plate count), when both incubations were at 21°-22° C for 96 h. If sustained in further experimentation, this last observation would mean that the Petrifilm SM system could be successfully used to detect bacterial populations in addition to those for which the system was originally intended.

scholarly journals Dibasic Esters of ortho-/meta-Alkoxyphenylcarbamic Acid Containing 1-Dipropylamino-3-Piperidinopropan-1-yl and Their Antimicrobial Activity

2014 ◽  
Vol 63 (2) ◽  
pp. 231-236
Author(s):  
JOZEF CSÖLLEI ◽  
IVAN MALÍK ◽  
MARIÁN BUKOVSKÝ ◽  
EVA SEDLÁROVÁ
Keyword(s):  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Side Chain ◽  
In Vitro Susceptibility ◽  
E Coli ◽  
Microdilution Method ◽  
Quantitative Screening ◽  
Significant Disease

In Europe, the presence of microorganisms that have become resistant to antimicrobials as the most significant disease threat has remained. The aim of the current research was to screen the in vitro susceptibility of Staphylococcus aureus, Escherichia coli and Candida albicans to the series of dibasic esters of ortho-/meta-alkoxyphenylcarbamic acid previously known for their local anaesthetic effectiveness and to contribute for the structure - antimicrobial potency relationships study within that class of the compounds. The antimicrobial activity investigation involved determination of the minimum inhibitory concentration (MIC) by applying the microdilution method; quantitative screening was performed on a blood agar (S. aureus), Endo agar (E. coli) or on Sabouraud's agar (C. albicans). The activity against all the microorganisms tested was primarily influenced by the position of alkoxy side chain attached to lipophilic aromatic ring and by its length as well. Inspected meta-alkoxy substituted derivatives have shown higher efficiency against all chosen microorganisms than their ortho-alkoxy positional isomers. The most promising results were observed when investigating the activity of meta-alkoxy substituted molecules against E. coli with the estimated MICs in the range of 12-49 microg/ml. Furthermore, such potency was found to be quasi parabolically dependent on alkoxy chain length achieving a maximum for meta-hexyloxy derivative which has shown MIC= 12 microg/ml. Considered compound was also regarded as the most effective against S. aureus with MIC = 98 microg/ml. Evaluating the potency against C. albicans, it was revealed that no molecule within the tested set displayed MIC < 100 microg/ml.

Antimicrobial activity of Romanian propolis ethanolic extracts against E. coli isolated from bovine mastitis

Planta Medica ◽  
2013 ◽  
Vol 79 (13) ◽  
Author(s):  
M Niculae ◽  
CD Sandru ◽  
E Pall ◽  
S Popescu ◽  
L Stan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Bovine Mastitis ◽  
E Coli ◽  
Ethanolic Extracts

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

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