scholarly journals Optimization of antimicrobial efficiency of silver nanoparticles against three oral microorganisms in irreversible hydrocolloid impressions

2021 ◽  
Author(s):  
Ahmad Jafari ◽  
Ramin Mazaheri Nezhad Fard ◽  
Sima Shahabi ◽  
Farid Abbasi ◽  
Golshid Javdani Shahedin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Ag Nps ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Irreversible Hydrocolloid ◽  
Predicted Model ◽  
Water Ratio

Background and Objectives: Silver nanoparticles (Ag-NPs) are potent antimicrobial agents, which have recently been used in dentistry. The aim of the current study was to optimize antimicrobial activity of Ag-NPs used in preparing irre- versible hydrocolloid impressions against three microorganisms of Escherichia coli, Streptococcus mutans and Candida albicans. Materials and Methods: After assessing antimicrobial activity of the compound using disk diffusion method, three parame- ters of concentration of Ag-NPs (250-1000 ppm), ratio of hydrocolloid impression material powder to water (0.30-0.50) and time of mixing (20.0-60.0 s), affecting antimicrobial activity of irreversible hydrocolloid impression materials against the three microorganisms, were optimized. This combined process was successfully modeled and optimized using Box-Behnken design with response surface methodology (RSM). Decreases in colony number of E. coli, S. mutans and C. albicans were proposed as responses. Results: Qualitative antimicrobial assessments respectively showed average zone of inhibition (ZOI) of 3.7 mm for E. coli, 3.5 mm for S. mutans and 4 mm for C. albicans. For all responses, when the mixing duration and powder-to-water ratio increased, the circumstances (mixing duration of 59.38 s, powder-to-water ratio of 0.4 and Ag-NP concentration of 992 response) increased. Results showed that in optimum ppm, the proportion of decreases in colony numbers was maximum (89.03% for E. coli, 87.08% for S. mutans and 74.54% for C. albicans). Regression analysis illustrated a good fit of the ex- perimental data to the predicted model as high correlation coefficients validated that the predicted model was well fitted with data. Values of R2Adj with R2Pred were associated to the accuracy of this model in all responses. Conclusion: Disinfection efficiency dramatically increased with increasing of Ag-NP concentration, powder-to-water ratio and mixing time.

scholarly journals Anti-microbial activity of heterocyclic cationic surface-active substances

2020 ◽  
Vol 24 (1) ◽  
pp. 36-40
Author(s):  
V. V. Pantyo ◽  
M. M. Fizer ◽  
O. I. Fizer ◽  
G. M. Koval ◽  
E.M. Danko
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Pathogenic Microorganisms ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Quantitative Studies ◽  
Ionic Associates ◽  
Surface Active

Annotation. The development and rapid pace of the spread of resistance to antimicrobial agents predetermines the search for new methods of counteracting pathogenic and conditionally pathogenic microorganisms. In this context, studies of the antimicrobial activity of newly synthesized chemicals, which in the future can be considered as candidates for antiseptic and disinfectants, are relevant. The aim of the work was to determine the antimicrobial activity of new ionic associates based on the surface-active cetylpyridinium cation with respect to certain opportunistic microorganisms. The antimicrobial activity of four ionic associates based on the cetylpyridinium cation with respect to clinical isolates of E. coli, P. vulgaris, K. pneumonia, P. aeruginosa, S. aureus, as well as the collection test strains of S. aureus ATCC 25923, E. coli ATCC 29522 and P. aeruginosa ATCC 27853 was studied. Screening studies were performed by the disk diffusion method. With substances that showed an antimicrobial effect, quantitative studies were carried out by the method of serial macro-dilutions in a liquid nutrient media. Screening studies revealed the antibacterial activity of the substances against E. coli ATCC 25923, E. coli (clinical isolate), P. vulgaris and K. pneumonia. With these microorganisms quantitative studies were carried out with the determination of the minimum inhibitory and minimum bactericidal concentrations. The most pronounced antimicrobial activity for the investigated microflora was shown by tetraphenylborate and cetylpyridinium perchlorate. The MIC and MBC values of these substances ranged between 1.625–3.125 mmol / L and 3.125–12.5 mmol / L, respectively. The studied associates showed high antimicrobial activity against representatives of the Enterobacteriaceae family in in vitro studies. Promising is the further study of the effect of the counter-anion associates of cationic surfactants on the biofilm formation of conditionally pathogenic microorganisms.

SEARCH FOR ANTIMICROBIAL AGENTS: QUINOXALINE AS A PROMISING TARGET

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (07) ◽  
pp. 5-9
Author(s):  
R. G Ingle ◽  
◽  
S. J. Wadher
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
E Coli ◽  
Promising Target ◽  
Quinoxaline Derivatives

A set of ten new 2,3-diphenyl-6-sulfonamido quinoxaline derivatives was synthesized and screened for antimicrobial activity by disk diffusion method. Test derivatives R3, R5, R’’1 and R’’2 show promising results against bacterial strains S. aureus gram positive and E. coli gram negative organism with the concentration 1000 μg/mL in disk diffusion method. Rest of the derivatives show sensitivity against the same organisms. All the synthesized derivatives were confirmed by their spectral data.

scholarly journals Occurrence of toxigenic Escherichia coli in raw milk cheese in Brazil

2007 ◽  
Vol 59 (2) ◽  
pp. 508-512 ◽  
Author(s):  
B.R. Paneto ◽  
R.P. Schocken-Iturrino ◽  
C. Macedo ◽  
E. Santo ◽  
J.M. Marin
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Antimicrobial Agents ◽  
Raw Milk ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Polymerase Chain ◽  
Raw Milk Cheese

The occurrence of toxigenic Escherichia coli in raw milk cheese was surveyed in Middle Western Brazil. Fifty samples of cheese from different supermarkets were analyzed for E.coli. The isolates were serotyped and screened for the presence of verotoxigenic E. coli (VTEC) and enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR). The susceptibility to thirteen antimicrobial agents was evaluated by the disk diffusion method. E.coli were recovered from 48 (96.0%) of the samples. The serogroups identified were O125 (6.0%), O111 (4.0%), O55 (2.0%) and O119 (2.0%). Three (6.0%) and 1(2.0%) of the E.coli isolates were VTEC and ETEC, respectively. Most frequent resistance was observed to the following antimicrobials: cephalothin (60.0%), nalidixic acid (40.0%), doxycyclin (33.0%), tetracycline (31.0%) and ampicillin (29.0%).

scholarly journals Antibiotic resistance and virulence genes of extraintestinal pathogenic Escherichia coli from tropical estuary, south India

2015 ◽  
Vol 9 (05) ◽  
pp. 496-504 ◽  
Author(s):  
Divya Sukumaran ◽  
Abdulla A Mohamed Hatha
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Virulence Factor ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Virulence Factor Genes

Introduction: Escherichia coli strains can cause a variety of intestinal and extraintestinal diseases. Extraintestinal pathogenic E. coli (ExPEC) strains have the ability to cause severe extraintestinal infections. Multidrug resistance among ExPEC could complicate human infections. Methodology: Escherichia coli strains were isolated during the period of January 2010 to December 2012 from five different stations set at Cochin estuary. Susceptibility testing was determined by the disk-diffusion method using nine different antimicrobial agents. A total of 155 strains of Escherichia coli were screened for the presence of virulence factor genes including papAH, papC, sfa/focDE, iutA,and kpsMT II associated with ExPEC. Results: Among the 155 E. coli isolates, 26 (16.77%), carried two or more virulence genes typical of ExPEC. Furthermore, 19.23% of the ExPEC isolates with multidrug resistance were identified to belong to phylogenetic groups B2 and D. Statistically significant association of iutA gene in ExPEC was found with papC (p < 0.001) and kpsMT II (p < 0.001) genes. ExPEC isolates were mainly resistant to ampicillin (23.07%), tetracycline (19.23%), co-trimoxazole (15.38%), and cefotaxime (15.38%). The adhesion genes papAH and sfa/focDE were positively associated with resistance to gentamicin, chloramphenicol, and cefotaxime (p < 0.05). Conclusions: Co-occurrence of virulence factor genes with antibiotic resistance among ExPEC poses considerable threat to those who use this aquatic system for a living and for recreation.

Multidrug-Resistant Escherichia coli Strains Isolated from Patients Are Associated with Class 1 and 2 Integrons

Chemotherapy ◽  
2015 ◽  
Vol 61 (2) ◽  
pp. 72-76 ◽  
Author(s):  
Hamid Lavakhamseh ◽  
Parviz Mohajeri ◽  
Samaneh Rouhi ◽  
Pegah Shakib ◽  
Rashid Ramazanzadeh ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Major Health ◽  
Mortality And Morbidity ◽  
E Coli ◽  
Class 1 ◽  
Dna Elements

Background:Escherichia coli isolates displaying multidrug-resistance (MDR) are a major health care problem that results in mortality and morbidity. Integrons are DNA elements in E.coli that are related to antibiotic resistance. The aim of this study was to determine class 1 and 2 integrons and MDR in E. coli isolates obtained from patients in two Sanandaj hospitals, located in Iran. Materials and Methods: 120 isolates of E. coli were obtained from clinical specimens (from November 2013 to April 2014), and the susceptibility of E. coli antimicrobial agents was determined using the Kirby-Bauer disk diffusion method according to the CLSI. PCR were applied for detection of class 1 and 2 integrons in E. coli isolates. SPSS software v16 and the χ2 test were used for statistical analysis in order to calculate the association between antibiotic resistance and the presence of integrons (p < 0.05). Results: In a total of 120 E. coli isolates, 42.5% had MDR. Integrons were found in 50.9% of the MDR isolates, and included 47.05% class 1 and 3.92% class 2 integrons. The strains did not have both classes of integrons simultaneously. An association between resistance to antibiotics and integrons was found. Conclusion: Our results showed that int1 and int2 genes present in E. coli isolates obtained from patients cause MDR in this isolates. Since such bacteria are a reservoir for the transmission of MDR bacteria, appropriate programs are necessary to reduce this problem.

Antimicrobial activity of raw soybean, soybean flour and roasted soybean extracted by ethanol-hexane method

2017 ◽  
Vol 119 (10) ◽  
pp. 2277-2286 ◽  
Author(s):  
Sireerat Laodheerasiri ◽  
Nirasha Horana Pathirage
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Antimicrobial Compounds ◽  
Soybean Flour ◽  
Hexane Extraction ◽  
Disk Diffusion Method ◽  
Content Type ◽  
E Coli ◽  
Inhibitory Compounds

Purpose The purpose of this paper is to determine the antimicrobial compounds extracted from various types of soybean materials; raw soybean, soybean flour and roasted soybean. Bacteria growth inhibition was tested in E.coli and S. aureus by disk diffusion method. Efficiency of antimicrobial activities were compared among the extracted solution. Design/methodology/approach Soybean (Glycine max) isoflavones contain the ability to inhibit the growth of many strains of microorganisms. The solid-liquid extraction, ethanol-hexane extraction, was modified to isolate the inhibitory compounds from the three different types of soybean materials. All crude extracts at various concentrations performed under different extracted solutions (75, 50, 25, 12.5, 6.25 and 3.125 percent) were tested with E. coli. and S. aureus to determine the antimicrobial activities and the minimum inhibition concentration (MIC). Disk diffusion method was chosen to study the antimicrobial activity of isoflavones. Findings Soybean flour extract inhibited the growth of E. coli and S. aureus more effective than roasted soybean and raw soybean, respectively. The MIC of inhibitory compounds extracted from soybean flour was 6.25 percent (0.031 mg/ml), roasted soybean was 25 percent (0.125 mg/ml) and raw soybean was 50 percent (0.250 mg/ml). Crude extracts of soybean flour and roasted soybean showed better results than raw soybean. All the three of extracted soybeans inhibited the growth of E. coli better than S. aureus. Originality/value Ethanol-hexane extraction was successfully used to isolate the antimicrobial compounds from raw soybean, soybean flour and roasted soybean. Comparison of antimicrobial activity showed that soybean flour contained the highest inhibition activity.

scholarly journals ANTIMICROBIAL ACTIVITY OF METHANOLIC EXTRACT OF LUDWIGIA PARVIFLORA L. AGAINST STANDARD BACTERIAL STRAINS AND COMPARISON OF ITS ACTIVITY WITH THAT OF STANDARD ANTIBIOTICS

2019 ◽  
pp. 430-432
Author(s):  
SHIBU GEORGE ◽  
MEVLIN JOY
Keyword(s):  
Antimicrobial Activity ◽  
Bacterial Infections ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Whole Plant ◽  
The Common ◽  
Susceptibility Tests

Objective: The objective of this study was to evaluate the antimicrobial activity of methanolic extract of Ludwigia parviflora L. using standard bacterial strains and compare its activity with that of standard antibiotics. Methods: The antibacterial activity and antibiotic susceptibility tests were done by disk diffusion method using MTCC bacterial strains. Results: The study revealed that the methanolic extract of the whole plant of L. parviflora L. was effective to inhibit the growth of Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Among the tested strains, S. aureus, P. aeruginosa, K. pneumoniae, and E. coli were more susceptible to the methanolic extract of L. parviflora than the commonly using antibiotic tetracycline 30 mcg. The activity of methanolic extract was also higher than the activity of gentamicin 10 mcg against the P. aeruginosa. Conclusion: The study concluded that the crude methanolic extract of the whole plant of L. parviflora L. is a good source for antibacterial agent against S. aureus, P. aeruginosa, K. pneumoniae, and E. coli. Hence, this plant can be used as a natural alternative to the common antibiotics such as gentamicin and tetracycline against common bacterial infections after validating its pharmacological and toxicological activities.

scholarly journals In vitro Synergistic Antimicrobial Activity of Romanian Propolis and Antibiotics against Escherichia coli Isolated from Bovine Mastitis

2015 ◽  
Vol 43 (2) ◽  
pp. 327-334 ◽  
Author(s):  
Mihaela NICULAE ◽  
Laura STAN ◽  
Emoke PALL ◽  
Anamaria Ioana PAȘTIU ◽  
Iulia Maria BALACI ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Bovine Mastitis ◽  
Antibacterial Properties ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Ethanolic Extracts

The study was aimed to characterize the chemical composition and the antimicrobial activity of Romanian propolis ethanolic extracts (EEP) against antibiotic-sensitive and antibiotic-resistant E. coli strains isolated from bovine mastitis. The preliminary antimicrobial screening was performed by a disk diffusion method, followed by determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) based on broth microdilution assay; further, the synergistic action of propolis with antimicrobial drugs was assessed by a disk diffusion method on agar containing subinhibitory concentrations of propolis. For the chemical characterisation of EEP, the flavonoids (flavones/flavonols, flavanones/dihydroflavonols) and total phenolics were evaluated by spectrophotometric methods. The phenolic compounds of these extracts were also determined using HPLC. The results indicated for Romanian propolis ethanolic extracts the typical poplar composition profile with flavonoids and phenolic acids as main biological active compounds, with chromatographic analysis data confirmed also spectrophotometrically. In addition, positively correlated with the chemical composition, a strong antimicrobial efficacy was exhibited towards E. coli strains, along with interesting synergistic interaction with antibiotics that can be further investigated to obtain propolis-based formulation with antibacterial properties. Subsequent in vitro and in vivo studies evaluating the safety and efficacy are intended to consider propolis in veterinary therapeutic protocols.

scholarly journals Investigation of Pathogenic Escherichia Coli from Diarrheic Calves in Selective Area of Bangladesh

2015 ◽  
Vol 13 (1) ◽  
pp. 45-51 ◽  
Author(s):  
AKMA Islam ◽  
M Rahman ◽  
A Nahar ◽  
A Khair ◽  
MM Alam
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Biochemical Properties ◽  
Molecular Techniques ◽  
Diffusion Method ◽  
Molecular Technique ◽  
Isolation And Identification ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Diarrheic Calves

Molecular technique was used to investigate the prevalence of virulent diarrheic genes in pathogenic Escherichia coli and their antibiotic sensitivity patterns. A hundred samples from 100 different diarrheic calves from mid-north-western part of Bangladesh were screened for the presence of virulence factors associated with diarrhea. Following isolation and identification on the basis of cultural, morphological and biochemical properties, the presence of the virulence genes such as eaeA, bfpA, elt, est, stx1 and stx2 were examined using PCR. Antimicrobial susceptibility of 57 E. coli was determined by agar disk diffusion method for 8 antimicrobial agents. Out of 100 samples 57 (57%) were found to be positive for E. coli and their distribution rates according to their age, breed and sex were  66.7% ( 6 days old ), 85.7% (Sahiwal breed) and in  64.2 % (female calves) respectively. Among 57 E. coli isolates, only 16 isolates were analyzed for the detection of the said genes. Among them, only eaeA gene was detected in 2 E. coli isolates (12.5 %). Antibiotic resistance patterns revealed that Oxacillin, Rifampicin and Penicillin were  100% resistant followed by Erythromycin which was more than 80% resistant. In case of Amoxicillin and Tetracycline, about 59.65% and 61.40% were found to be resistant respectively whereas all 57 E. coli isolates showed moderately susceptible (30%) to Cefuroxime, a second generation Cephalosporin. Therefore, none of the eight antimicrobials studied can not be recommended as single best therapeutic agent for the treatment of neonatal calf diarrhea. In addition, this study indicated that diarrhea in calves in these locations can be ascribed to mainly Enteropathogenic E. coli (EPEC) which was atypical (only contained the eaeA genes but not bfpA). However, further studies are necessary to characterize the isolated eaeA gene positive E. coli by serotyping, tissue culture assay and other molecular techniques to find out the potentiality of those virulent genes contributing pathogenicity of E. coli causing diarrhea in calves.DOI: http://dx.doi.org/10.3329/bjvm.v13i1.23716Bangl. J. Vet. Med. (2015). 13 (1): 45-51

scholarly journals Resistance to multiple first-line antibiotics among Escherichia coli from poultry in Western Algeria

2020 ◽  
Vol 13 (2) ◽  
pp. 290-295
Author(s):  
Meki Boutaiba Benklaouz ◽  
Hebib Aggad ◽  
Qada Benameur
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
First Line ◽  
Resistance Level ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Mueller Hinton Agar ◽  
Western Algeria

Background and Aim: Escherichia coli can cause a number of serious infections both in human and veterinary medicine. Their management is increasingly complicated by the emergence and dissemination of multiresistance to various first-line antimicrobial agents. This study aimed to evaluate the resistance level to the commonly used antibiotics, with a focus on the first-line antimicrobial agents, in E. coli strains isolated from poultry in Western Algeria. Materials and Methods: E. coli culture was done on MacConkey agar and their identification was determined by AP20E system. For susceptibility testing, disk diffusion method to 14 antimicrobials, including first-line antibiotics, was used according to Kirby–Bauer disk diffusion method in Mueller-Hinton agar and the results were interpreted according to the Clinical and Laboratory Standards Institute guidelines. E. coli isolates were considered as multidrug resistance (MDR) when found resistant to at least one antimicrobial agent of three different families of antibiotics. Double-disk synergy and combination disk tests were used for initial screening and confirmation for extended-spectrum β-lactamases (ESBLs) production, respectively. Results: A total of 145 E. coli strains were isolated in this study. High resistance levels to various antibiotics, including commonly used first-line antimicrobial agents, were recorded in this study. The highest resistance level was observed against nalidixic acid (90.34%, n=131), followed by tetracycline (86.89%, n=126), ampicillin (82.75%, n=120), enrofloxacin (80.68%, n=117) and neomycin (80.68%, n=117), trimethoprim/sulfamethoxazole (73.79%, n=107), norfloxacin (72.41%, n=105) and cephalothin (72.41%, n=105), amoxicillin/clavulanic acid (51.72%, n=75), chloramphenicol (22.75%, n=33), nitrofurantoin (17.24%, n=25), gentamicin (13.10%, n=19), and ceftiofur (3.44%, n=5). Moreover, resistance to multiple first-line antibiotics was also demonstrated in the present study. Overall, 139 out of 145 isolates (95.86%) demonstrated MDR (resistant to at least three antibiotics). In addition, five E. coli isolates (3.44%) were confirmed to be ESBL producers. Conclusion: The alarming rate of E. coli resistant to multiple first-line antibiotics in poultry demands intensified surveillance. These results call for taking drastic measures to preserve antibiotic effectiveness and reduce the emergence risks of extensively drug-resistant and pandrug-resistant E. coli isolates.

Sign in / Sign up

Export Citation Format

Share Document