Agar Plate Diffusion Research Articles

Antimicrobial assay of papaya seed ethanol extract (Carica papaya Linn) and phytochemical analysis of its active compounds

Natural drugs usage as alternative treatment has been increased in decades. This is due to the ‘back to nature’ life style of people and the side effect of natural drugs are relatively low. The prices of these natural drugs are cheaper as well. Papaya seed is one of the natural product with antimicrobial effect. The objectives of this research were to determine Minimum Inhibitory Concentration (MIC) of papaya seed ethanol extract to inhibit the growth of Candida albicans and Vibrio cholera and to analyze its active compounds. This research was performed using experimental design laboratory. The ethanol extract of papaya seed was obtained by maceration. The antimicrobial assay of papaya seed ethanol extract was performed using agar plate diffusion. The MIC determination of papaya seed ethanol extract was performed by 20, 15, 10, 5 and 1% concentration. The MIC of papaya seed ethanol extract against Candida albicans and Vibrio cholerae were in 5% concentration (diameter of inhibition zone=0.75 mm) and 15% (diameter of inhibition zone = 14.75 mm), respectively. The phytochemical assay of papaya seed ethanol extract showed there were alkaloids, flavonoids, steroids, polyphenols, tannins and saponins. It means that papaya seed ethanol extract has a good potential as antimicrobial therapy agent.

Evaluation of antibacterial activity of three different glass ionomer cements on streptococcus mutans: an in-vitro antimicrobial study.

AimPurpose of this in-vitro study was to assess and compare the antimicrobial activity of three different glass ionomer cements (GIC) against streptococcus mutans (S. mutans) bacteria using agar plate diffusion test.MethodsThirty blood agar plates were prepared and three wells of 4mm diameter were made on each agar plate. Three different GIC (Micron bioactive, GC Fuji IX GP Extra, Bioglass r) were mixed and filled into the wells. These plates were inoculated with S. Mutans and incubated at 37°C for 24 hours. Bacterial growth inhibition zone around each well were recorded in millimeters using Hiantibiotic Zonescale-C.ResultAll the restorative material used in the study exhibited antimicrobial property against S. Mutans. GC Fuji IX GP Extra showed superior antimicrobial efficacy with 17.3±2.6 mm mean diameter of bacterial inhibition zone, followed by Micron bioactive 14.4±1.07 mm and Bioglass r 10.8 ± .91 mm inhibition zone respectively.ConclusionWithin the limitation of this study, it can be concluded that all the GIC evaluated demonstrated antibacterial activity against S. mutans. The superior antimicrobial activity was demonstrated by GC Fuji IX GP Extra. Hence, it could be advantageous in patients with high caries risk.

Antimicrobial activity of the ethanolic extract of propolis against bacteria that cause mastitis in cattle

A própolis é uma substância coletada por abelhas, especialmente pela Apis mellifera, a partir de resinas de brotos de plantas que possuem numerosas propriedades biológicas, como antimicrobiana e antiinflamatória. Atividades como a pecuária leiteira orgânica apresentam alta demanda por produtos naturais com propriedades como as presentes na própolis, uma vez que a contaminação do leite e a mastite são grandes problemas da indústria de laticínios. O objetivo deste trabalho foi avaliar a atividade antimicrobiana in vitro do extrato etanólico de própolis (EEP) em diferentes concentrações. Ação do EEP extraído de colmeias no sul do Brasil foi testada contra 13 diferentes gêneros de agentes bacterianos causadores de mastite em bovinos leiteiros. O experimento foi conduzido no laboratório de Parasitologia e Microbiologia da Universidade Federal do Pampa, Campus Dom Pedrito – RS, durante os meses de maio e junho de 2016. Seguiram-se as técnicas de difusão em ágar e microdiluição em placas. Através dos resultados do teste de concentração inibitória mínima (CIM), pode-se afirmar que o EEP possui atividade inibitória em 100% das bactérias testadas em concentrações acima de 10% (p/v). Tais resultados mostram que a própolis apresenta potencial antimicrobiano frente as principais bactérias envolvidas nos processos de mastite.

Pharmacognostical, Preliminary phytochemical screening and Antibacterial activity of methanol Extract of Murraya koenigii

The methanol extract of murraya koenigii (leaf) were investigated for their antibacterial activity against staphylococcus aureus using cup plate agar diffusion method and methanol extract produces best results. Various investigations like physiochemical standard, preliminary phytochemical screening of the plant was carried out and parameters were reported. The present paper deals with investigation of various phytochemical present in methanol extract and in vitro antibacterial activity against the s.aureus. The literature survey does not exist antibacterial activity of murraya koenigii (leaf) in methanol extract against s.aureus. It is concluded that the plant studied may source of antibacterial plant.

Anti-Candida activity of beneficial vaginal lactobacilli in in vitro assays and in a murine experimental model.

Vulvovaginal candidiasis (VVC) is one of the most frequent infections affecting women worldwide. Healthy vaginal microbiota is dominated by lactobacilli, which form a strong defense line against pathogens. In this work, in vitro antimicrobial properties of thirty vaginal Lactobacillus strains were evaluated against eleven Candida vaginal clinical isolates, employing three different methods. Also, the effect of intravaginal (i.va.) administrations (preventive, therapeutic and preventive-therapeutic) of L. reuteri CRL1324 or L. rhamnosus CRL1332 strains against the i.va. challenge with Candida albicans C2 (C.a.) was evaluated in a murine experimental model. From the results of agar overlay and liquid medium assays the selected lactobacilli strains have shown to inhibit the growth of at least one Candida strain. The inhibition was mainly due to the effect of organic acids. Anti-Candida activity was not evidenced in the agar plate diffusion method. In the experimental murine model, only preventive-therapeutic administration of both lactobacilli was able to significantly reduce viable C.a. numbers recovered in vaginal washes and the leukocyte influx induced by the fungi. In conclusion, lactobacilli exhibited in vitro and in vivo antimicrobial effects on Candida, suggesting that they could be promising candidates for protection against VVC.

Surface functionalization and antibacterial activity of biomedical textiles with metal oxides-carbon nanocomposites

Carbon nanostructures were synthesized from honey by hydrothermal method. The synthesized nanocarbon structures were treated with synthesized Fe2O3 and TiO2 nanoparticles to form nanocomposites (NC). The synthesized nonaoparticles and their composites with carbon nanostructures were validated by XRD, FTIR, SEM and TEM for their morphology and microstructures. XRD analysis revealed the crystallographic structure of Fe2O3, TiO2 and the amorphous nature of carbon nanostructures . A rod like structure for Fe2O3 and TiO2, and nano sheet like structure for carbon was observed by TEM. The NC was impregnated onto fabrics and the presence of the NC on to the fabrics was confirmed by Laser Raman, FTIR and EDAX. The antibacterial effects of NC impregnated fabrics were evaluated against gram positive and gram negative bacteria by agar diffusion plate test. The NC fabrics showed a clear zone of inhibition, indicating good antibacterial activity against both bacterial strains. The washing test revealed durability of the coated fabrics.

607. Group B Streptococcus Resistance to Clindamycin: Regional Antibiogram Surveillance in Los Angeles County

BackgroundIntrapartum antibiotic prophylaxis (IAP) prevents neonatal mortality from Group B Streptococcus (GBS). Clindamycin resistance among GBS isolates complicates IAP for GBS-positive women allergic to penicillin and cephalosporins. GBS screening by nucleic acid amplification tests (NAATs) provides rapid results, but no susceptibility data to inform IAP. We sought to estimate burden of clindamycin resistance among GBS in Los Angeles County (LAC).MethodsHospital antibiogram data were gathered from all LAC acute care hospitals from 2015 to 2016. Weighted averages for GBS resistance to clindamycin, erythromycin, penicillin, and TMP/SMX were calculated. Facilities which reported clindamycin susceptibilities were interviewed regarding antimicrobial susceptibility testing methods.ResultsA total of 2,339 GBS isolates from 22 hospitals were reported between 2015 and 2016. Thirteen hospitals tested GBS for clindamycin (nine reported in 2015 and 2016, four hospitals reported in 2016 only). Clindamycin resistance was found in 61.7% of 1,794 GBS isolates (79.3% of 891 in 2015, 44.3% of 903 in 2016). Erythromycin resistance was 42% in 735 isolates reported, 0.1% penicillin of 1,916 isolates reported, and 1.5% TMP/SMX of = 135 isolates reported. Facilities tested GBS by manual minimum inhibitory concentration (MIC) broth dilution (n = 1), automated MIC dilution (n = 4), agar plate diffusion (n = 1), and MIC dilution followed by agar plate diffusion (n = 1). Two hospitals did not perform testing on-site.ConclusionThe 62% prevalence of clindamycin-resistant GBS in LAC is three-fold higher than national CDC estimates and complicates IAP for GBS-positive women allergic to penicillin and cephalosporins. These data support CDC recommendations for susceptibility testing in addition to NAAT screening which does not include assays for common determinants of clindamycin resistance, erm-methylase, mef, and isa. There is an opportunity for diagnostic manufacturers and clinical labs to help clinicians choose appropriate IAP and prevent neonatal mortality. The CDC and public health should be aware of regional variations in clindamycin resistance. Clinicians should be aware of local resistance to inform IAP stewardship recommendations.Disclosures S. Butler-Wu, BioFire (bioMerieux): Investigator, Research support.

Preparation and characterizations of multifunctional PVA/ZnO nanofibers composite membranes for surgical gown application

Herein, we developed the multifunctional; antibacterial, ultraviolet rays (UV) protected and self-cleaning surgical gown by blending of zinc oxide (ZnO) nanoparticles with poly vinyl alcohol (PVA). For this objective, ZnO NPs were blended in three different concentrations: 5wt%, 7wt% and 9wt% in 10wt% of PVA solution. The morphology of resultant nanofibers was observed under scanning electron microscope and transmission electron microscope and these studies showed the bead-free nanofibers and good dispersion of nanoparticles on nanofibers. Fourier Transform Infrared spectroscope was used for chemical interactions, wide-angle X-ray diffraction (WAXD) was used for analyzing the crystalline structure, agar diffusion plate method was used for antibacterial activity and it showed the effective response of bacteria killing. UV transmission analysis was done by Ultraviolet transmission analyzer, photo-catalytic activity was done by the solar simulator, stress–strain behavior was studied by tensile strength, and water contact angles measurements were done by contact angle meter. On the behalf of characterization results, PVA/ZnO nanofibers were exhibited the desired objectives for the surgical gown. This multifunctional surgical gown is beneficial for medical surgeon against the bacteria, stains and UV blocking to save his/her life.

PLGA-amoxicillin-loaded layer formed on anodized Ti alloy as a hybrid material for dental implant applications

In this paper, the preparation of a functional hybrid coating loaded with a drug (amoxicillin) on a promising titanium alloy – Ti-15Mo alloy is presented. The titanium alloy surface was anodized in solution with bioactive compounds to obtain a porous oxide layer favorable for MG-63 osteoblast-like cell adhesion. Then, a poly(lactide-co-glycolide) (PLGA) loaded with amoxicillin layer was formed using a dip-coating technique to cover the oxide layer, without filling in all of the pores. The morphology of the surface was evaluated using scanning electron microscopy supported by 3D Roughness Reconstruction software. The surface treatment of the Ti-15Mo alloy surface caused the surface roughness to increase up to 1.71 μm. The anodization process caused the Ti-15Mo alloy surface to become slightly more hydrophilic; however, the formation of the PLGA layer loaded with drug increased the contact angle to 96.5° ± 2.2°, respectively. After 4 weeks of polymer layer degradation, the registered signals on the 1H NMR spectrum were identical to the signals registered for lactic acid (LAc), which confirms that the polymer layer was degraded within a short period of time. The concentration of drug released into the artificial saliva was investigated using high-performance liquid chromatography (HPLC) up to 12 h of coatings immersion. During the first hour of coating degradation in artificial saliva, and the concentration of the drug (13 μg/ml) was enough to inhibit bacterial growth of S. aureus and S. epidermidis. These results were confirmed by agar plate diffusion method and evaluation of the minimal inhibitory concentration (MIC). The cytocompatibility of the materials was determined using the osteoblast-like cells MG-63, and the viability and cell morphology (live/dead staining) were also evaluated. The results showed that amoxicillin influences the osteoblast-like MG-63 cells' behavior during cell culture, especially for the first few hours. The influence on the type of surface treatment on MG-63 cell behavior during 7 days of culture is discussed in this paper. To the best of our knowledge, this is the first time that a fast-degrading layer with amoxicillin has been deposited on previously anodized Ti surface. The formation of functional coating may find application as a cytocompatible coating to prevent bacterial adhesion on long-term implant surfaces.

Characterization and Identification of a Streptomyces Strain with Biocontrol Activity against Aeromonas Hydrophila Causing Haemorrhage Disease in Fish

In this study, experiments were performed to identify and screen Streptomyces strains that are antagonistic to Aeromonas hydrophila, which causes hemorrhagic disease in fishes. Among 80 isolates, 3 strains capable of antagonizing Aeromonas hydrophila by the agar diffusion plate method were obtained. The strain numbered 1083 had a strong activity with a 25 mm diameter clear zone of bacteria. This strain showed grey colonies after 7 days of incubation. After 7 days of incubation, the grey colonies had white borders, produced soluble pigments on the medium, grew well at 30°C and neutral pH, and adapted well to medium containing a high salt concentration. Strain 1083 was able to utilize different sources of carbon and nitrogen. Sequence analysis of 16S rRNA showed that strain 1083 had a similarity of 99% compared to Streptomyces antibioticus. Based on morphological, physiological, and biochemical characteristics, as well as molecular biological analysis, strain 1083 was identified as Streptomyces antibioticus.

English

Aframomum melegueta (Roscoe) K. Schum, family of Zingiberaceae, is a tropical tree with spicy edible fruit. This plant has both medicinal and nutritive values. There is paucity of literature on the toxicity and bioactivity of the essential oils from this plant from Nigeria. Essential oils were extracted from the leaves, stems, roots (rhizomes) and seeds of the plant through hydro-distillation using the Clevenger-type apparatus. The toxicity of the volatile oils was determined using the brine shrimp toxicity assay at concentrations of 10.0, 100.0 and 1000.0 ppm and the median lethal concentration (LC50) was calculated using Finney’s probit analysis. The antimicrobial assay was carried out using the cup plate agar diffusion method. Five bacteria consisting of three strains of Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis and Salmonella typhi) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were screened.  The stems’ essential oil displayed the highest toxicity (LC50 = 0.2 µg/mL) followed by the seeds’ essential oil (LC50 = 0.3 µg/mL), while LC50 of the essential oil from the leaves offered the least toxicity (LC50 = 17.5 µg/mL) in brine shrimp toxicity assay. All essential oils showed moderate inhibition of the tested bacteria at 1mg/mL but showed no inhibition below 125 µg/mL concentration. The high brine shrimps’ toxicity and bactericidal activity of the essential oils is indicative of their potentials as sources of pharmaceuticals or natural pesticides. Key words: Essential oils, brine shrimps toxicity, bactericidal activity, A. melegueta

Fabrication of cotton fabrics with durable antibacterial activities finishing by Ag nanoparticles

In this paper, we propose a facile and mild route to prepare size-tunable silver nanoparticles (Ag NPs) and their finishing application on fabrication of antibacterial cotton fabrics. The as-prepared Ag NPs, with an average particles size of 2.3 nm, show the minimal inhibitory concentration of 7.8 µg/mL and the minimum bactericidal concentration of 15.6 µg/mL, respectively. In this study, sodium citrate served as a stabilizing agent to prevent Ag NP agglomeration in the synthesis process, and citric acid acted as a binder to fix Ag NPs on the cotton fabrics through chemical bonds in the finishing process. The results of Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy demonstrate that Ag NPs have been fixed and well dispersed on the cotton fabric surface. Ag contents in the hybrid fabrics were measured by the techniques of inductively coupled plasma atomic emission spectroscopy and UV-vis, and the antibacterial properties of hybrid fabrics were tested by the shake flask and agar diffusion plate method. It is found that the Ag NP coated cotton fabrics exhibit excellent antimicrobial activities against both the Gram-negative bacterium of Escherichia coli (E. coli) and the Gram-positive bacterium of Staphylococcus aureus ( S. aureus). The percentages of reduction bacteria remain at 91.8% and 98.7% for S. aureus and E. coli, respectively, even after 50 cycles of consecutive laundering, which indicates that the antibiotic performance of the as-fabricated hybrid fabrics is also durable.

DESIGN AND SYNTHESIS OF BENZODIAZEPINES BEARING BENZIMIDAZOLE/BENZOTHIAZOLE AND INDOLE MOIETIES AS A POTENT ANTIMICROBIAL AND ANTIOXIDANT AGENTS

Objective: The present work deals with the synthesis and characterization of biologically active new indole derivatives, namely, 2-((1H-benzo[d] imidazol-2-yl) thio)-N-(4-(4-(1H-indol-3-yl)-8-methyl-1H-benzo[b][1,4]diazepin-2-yl) phenyl) acetamide 3a-d, N-(4-(4-(1H-indol-3-yl)-8-methyl- 1H-benzo[b][1,4]diazepin-2-yl) phenyl)-2-((5-methoxy-1H-benzo[d]imidazol-2-yl) thio) acetamide 4a-d and N-(4-(4-(1H-indol-3-yl)-8-methyl-1H-benzo[b][1,4]diazepin-2-yl) phenyl)-2-(benzo[d]thiazol-2-ylthio) acetamide 5a-d.Methods: All these newly synthesized compounds were screened for their in vitro antimicrobial activity by an agar plate diffusion method, antioxidant activities such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), radical scavenging activity (RSA), ferric ions (Fe3+) reducing antioxidant power (FRAP), and ferrous (Fe2+) metal ion chelating activity.Result: The structures of all the newly synthesized compounds were characterized by their infrared,1H nuclear magnetic resonance, mass spectral studies, and elemental analysis. Compounds 7a and 7b exhibited good RSA at a concentration 100 μg/ml, compounds 6d, 7a-d and 8a-c displayed good FRAP at a concentration 100 μg/ml, compounds 7b-d and 8b-d showed good Fe2+ ion metal chelating activity. Compounds 6b, 6d, 7a-d, and 8a-d exhibited good activity against all the screened bacteria and fungi.Conclusion: Some of the compounds have shown potent antimicrobial activity against all the screened bacteria and fungi, and some have exhibited very good antioxidant activity.

DESIGN AND SYNTHESIS OF BENZODIAZEPINES BEARING BENZIMIDAZOLE/BENZOTHIAZOLE AND INDOLE MOIETIES AS A POTENT ANTIMICROBIAL AND ANTIOXIDANT AGENTS

Objective: The present work deals with the synthesis and characterization of biologically active new indole derivatives, namely, 2-((1H-benzo[d] imidazol-2-yl) thio)-N-(4-(4-(1H-indol-3-yl)-8-methyl-1H-benzo[b][1,4]diazepin-2-yl) phenyl) acetamide 3a-d, N-(4-(4-(1H-indol-3-yl)-8-methyl- 1H-benzo[b][1,4]diazepin-2-yl) phenyl)-2-((5-methoxy-1H-benzo[d]imidazol-2-yl) thio) acetamide 4a-d and N-(4-(4-(1H-indol-3-yl)-8-methyl-1H-benzo[b][1,4]diazepin-2-yl) phenyl)-2-(benzo[d]thiazol-2-ylthio) acetamide 5a-d.Methods: All these newly synthesized compounds were screened for their in vitro antimicrobial activity by an agar plate diffusion method, antioxidant activities such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), radical scavenging activity (RSA), ferric ions (Fe3+) reducing antioxidant power (FRAP), and ferrous (Fe2+) metal ion chelating activity.Result: The structures of all the newly synthesized compounds were characterized by their infrared,1H nuclear magnetic resonance, mass spectral studies, and elemental analysis. Compounds 7a and 7b exhibited good RSA at a concentration 100 μg/ml, compounds 6d, 7a-d and 8a-c displayed good FRAP at a concentration 100 μg/ml, compounds 7b-d and 8b-d showed good Fe2+ ion metal chelating activity. Compounds 6b, 6d, 7a-d, and 8a-d exhibited good activity against all the screened bacteria and fungi.Conclusion: Some of the compounds have shown potent antimicrobial activity against all the screened bacteria and fungi, and some have exhibited very good antioxidant activity.

Isocyanate‐Free, UV‐Crosslinked Poly(Hydroxyurethane) Networks: A Sustainable Approach toward Highly Functional Antibacterial Gels

An increased sustainabile awarness has inspired the development of new polymeric networks in a remarkable way and this strive should be combined with environmentally concerned end-uses. Therefore, a UV-crosslinked polyhydroxyurethane film with antibacterial properties is developed. First, a hydroxyurethane precursor is synthesized using aminolysis condensation, circumventing the use of isocyanates. The films are subsequently crosslinked under solvent-free conditions through a UV-triggered thiol-ene mechanism. The reactions are monitored by 1 H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy, and the networks have gel contents above 90%, and are transparent, hydrophilic, and highly flexible. Antibacterial properties are achieved by a controlled quaternization of the network's tertiary-amine and methylation of thiol-ether functionality, resulting in quaternary ammonium compounds (QACs) and sulfonium compounds. The antibacterial properties are evaluated against both Escherichia coli and Staphylococcus aureus using the agar plate diffusion and tube shaking methods. The QAC-loaded films exhibit outstanding bactericide properties (>99.9%) and the antibacterial mechanism is demonstrated to be a dual killing mechanism, i.e., diffusion killing and contact active killing.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF INDOLE DERIVATIVES BEARING BENZIMIDAZOLE/BENZOTHIAZOLE MOIETY

Objective: The present work deals with the synthesis and characterization of biologically active new indole derivatives viz., 2-((1H-benzo[d]imidazol-2-yl)thio)-N-(4-(3-(1H-indol-3-yl)acryloyl)phenyl)acetamide 6a-d, N-(4-(3-(1H-indol-3-yl)acryloyl)phenyl)-2-((5-methoxy-1H-benzo[d]imidazol-2-yl)thio)acetamide 7a-d and N-(4-(3-(1H-indol-3-yl)acryloyl)phenyl)-2-(benzo[d]thiazol-2-ylthio)acetamide 8a-d.Methods: All these newly synthesized compounds were screened for their in vitro antimicrobial activity by an agar plate diffusion method, antioxidant activities: like 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity (RSA), ferric ions (Fe3+) reducing antioxidant power (FRAP), ferrous (Fe2+) metal ion chelating activity.Results: The structures of all the newly synthesized compounds were characterized by their IR, 1HNMR, mass spectral studies and elemental analysis. Compounds 6b, 7a, 7b, 8a and 8b exhibited good radical scavenging activity (RSA) at a concentration 100 µg/ml, compounds 7b, 7c, 7d and 8b displayed good ferric ions (Fe3+) reducing antioxidant power (FRAP) at a concentration 100 µg/ml, compounds 7b, 7d, 8b and 8d showed good ferrous (Fe2+) ion metal chelating activity. Compounds 7d and 8d exhibited good activity against all the screened bacteria and fungi.Conclusion: The synthesised compounds 7d having methoxy group at 5 positions of benzimidazoles ring, bromo group at 5 positions of indole ring, and 8d having bromo group at position 5 of indole ring, both the compounds have exhibited potent antimicrobial activity. Some compounds have shown very good antioxidant activity.

FLOATING GASTRORETENTIVE OF AMOXICILLIN USING HARD ALGINATE CAPSULES AND ITS ANTIBACTERIAL ACTIVITIES

Objective: The aim of this study was to formulate floating gastroretentive of amoxicillin using hard alginate capsules shell and to evaluate antibacterial activities of floating gastroretentive of amoxicillin.Methods: Alginate capsules shell were made by using sodium alginate 80-120 cP. Amoxicillin was prepared in solid dispersion to obtain sustained release requirement for 12 hours. Solid dispersion was prepared by solvent method using polyvinylpyrrolidone (PVP) K30. The solid dispersion was characterized by X-ray diffraction and FTIR analysis. The drug release test was carried out by using USP paddle method in simulated gastric fluid. Concentrations of amoxicillin were determined by using spectrophotometer UV at 272 nm. The antibacterial activity of aliquots dissolution were assessed by using agar plate diffusion method against Staphylococcus aureus and Escherichia coli as bacterial model.Results: The alginate capsules shell were made from sodium alginate 80-120 cP with size 0. The dissolution test results showed that amoxicillin in the form of solid dispersions with weight ratio amoxicillin with PVP K30 was 1:1 provided sustained release of amoxicillin during 12 hours, while the release of amoxicillin without solid dispersion was too slow. The floating lag time was 0 minute and floating time was more than 12 hours. The X-ray diffraction pattern of amoxicillin solid dispersion had amorphous shape. Antibacterial activity test showed that the dissolution aliquots of amoxicillin solid dispersion were effective against Staphylococcus aureus and Escherichia coli.Conclusions: Based on the results of this study, it is concluded that the alginate capsules shell can be used for preparation of floating gastroretentive of amoxicillin using amoxicillin solid dispersion and the dissolution aliqouts give antibacterial effect.Keywords: Floating; gastroretentive; alginate capsule; amoxicillin; solid dispersion; release; antibacterial

In vitro effect of vaginal lactobacilli on the growth and adhesion abilities of uropathogenic Escherichia coli.

Escherichia coli is one of the main causes of uncomplicated urinary tract infections and responsible of vaginal infections. Lactobacilli can inhibit this pathogen by the production of antimicrobial substances as organic acids, hydrogen peroxide and/or bacteriocins. The aim of this work was to study the effects of beneficial vaginal lactobacilli on E. coli through in vitro experiments. The inhibitory activity of three vaginal Lactobacillus strains against E. coli was assessed using the agar plate diffusion. Moreover, the effect of Lactobacillus reuteri CRL (Centro de Referencia para Lactobacilos Culture Collection) 1324 on the adhesion and internalization capabilities of E. coli was studied on HeLa cells. Two Lactobacillus strains inhibited the growth of the pathogens by production of organic acids. L. reuteri CRL 1324 reduced the adhesion and internalization of E. coli 275 into HeLa cells. The results obtained suggest that L. reuteri CRL 1324 can be considered as a probiotic candidate for further in vivo studies for the prevention or treatment of urinary tract infections caused by E. coli.

Study on E. coli and Salmonella biofilms from fresh fruits and vegetables.

Foodborne outbreaks associated with fresh fruits and vegetables are on the rise worldwide. Biofilm formation is one of the important traits of pathogens making them strongly attached to substrates as well as express virulence phenotypes. Present study investigates the biofilm forming ability of E. coli and Salmonella sp. isolated from fresh fruits and vegetables. A total of 53 strains, including 35 E. coli and 18 Salmonella sp. isolated from different fruit and vegetable samples were taken into account for the study. Initial screening for biofilm formation was done using Congo Red agar plate test. Results revealed that 22.8% E. coli and 22.2% Salmonella sp. were potential biofilm formers. However, the MTP (Micro-Titre Plate) assay suggested more isolates of both E. coli and Salmonella sp. were moderate to strong biofilm producers. Agar plate diffusion assay with Agrobacterium tumefaciens NTL-4 showed the production of quorum signaling molecules (AHLs) by three isolates of E. coli and one Salmonella sp. Two E. coli isolates showed a significant amount of EPS production indicating higher biofilm forming potential. The Presence of LUX R homologue gene (sdiA) in two of the Salmonella isolates were confirmed by PCR which demonstrated their potential pathogenicity. Results of the work underline the biofilm forming and potentially virulent capacities of isolates from the surface of fruits and vegetables.

In vitro evaluation of antimicrobial efficacy of 2% chlorhexidine loaded electrospun nanofibers

IntroductionPersistent endodontic infection might be due to retention of microorganisms in dentinal tubules of root canal. C. albicans and E. faecalis are commonly found micro organisms in root canals of previously treated teeth. These micro organisms have shown to be resistant to most of the anti microbial agents used during root canal treatment but were found to be sensitive to Chlorhexidine (CHX). AimThis invitro study was conducted to evaluate the efficacy of 2% Chlorhexidine loaded eletrospun nanofibres and compare them with Chlorhexidine solution and gel in a pour plate or traditional streak agar diffusion model. MethodologyStandard holes in the cultivated Sabroaud's Dextrose and Muller Hinton agar plates were filled with one of the CHX preparations i.e 2% Chlorhexidine gluconate solution, 2% CHX gel, 2% CHX loaded electrospun nanofibre. The zones of microbial inhibition were measured after 24 and 72 hours of incubation at 37°C. Values obtained were subjected to statistical analysis. ResultsCHX Nanofibre showed values of zone of inhibition higher than solution (p≤0.05) and similar to that of gel. ConclusionCHX NF and gel had similar antimicrobial efficacy and CHX solution was least effective.