Minimum Inhibitory Concentration Method Research Articles

Testing Antioxidant And Antibacterial Activity Of Andaliman Fruit (Zanthoxylum Acanthopodium Dc.) Ethanol Extract With Abts Method (2,2'-Azino-Bis(3-Ethylbenz-Thiazoline-6-Sulfonic Acid) And Minimum Resistant Concentration

Antioxidants are chemical compounds that can donate one or more electrons to free radicals, so that these free radicals can be quenched. There are two sources of antioxidants, namely natural and synthetic antioxidants. Andaliman (Zanthoxylum acanthopodium DC.) is one of the many spice plants found in Toba Samosir and North Tapanuli Regencies, North Sumatra. Andaliman plants grow at an altitude of 1,500 m above sea level. Apart from North Sumatra. This research using method experimental research when collecting and processing andaliman fruit, making simplicia, making ethanol extracts and examining antioxidant activity tests using the ABTS free radical scavenging method (2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) and antibacterial activity. using the minimum inhibitory concentration method. Testing the antioxidant activity of the ethanol extract of andaliman fruit with the ABTS method using a UV-VIS spectrophotometer with a wavelength of 734 nm. the regression equation (y = 0.4619 + 20.226) obtained an IC50 value of 64.4598 mg/mL which can be classified as a strong antioxidant activity. The results of the antibacterial activity test of the ethanol extract of the andaliman fruit showed that the extract had antibacterial activity in the moderate category at a concentration of 300 mg/ml with an inhibition zone of 10.

BACTERIAL INHIBITORY EFFECT OF ALGERIAN POMEGRANATE (Punica Granatum L.) EXTRACTS (PEEL, JUICE, AND SEED) AGAINST MULTIDRUG RESISTANT BACTERIA

Punica granatum L. (pomegranate) is known popularly by its nutritional values and healthy benefits. The current study is aimed the evaluation of antibacterial effects of Punica granatum fruit extracts that cultivated in Algeria against environmental and clinical isolates of β-lactamase producing methicillin resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase ESBL-producing Enterobacteriaceae by using agar diffusion methods and minimum inhibitory concentration (MIC)-determination. Moreover, the extracts were investigated for their phenolic content by the Folin-Ciocalteu method. The quantitative assays of total polyphenols revealed a richness of the different pomegranate extract in polyphenols, peel and seed ethanol extracts contain the highest values (880.06 ± 11.2 mg GAE/100 g and 1160.1 ± 45.20 mg GAE/100 g, respectively). Flavonoid contents were high in both of acetone, ethanol extracts of peel, followed by ethanol, and acetone extracts of juice. According to the disc diffusion data, all phenolic extracts had a bacterial inhibitory effect against all extended-spectrum beta-lactamase ESBL-producing Enterobacteriaceae with a strong inhibitor with MIC 512 g/mL strength. The pericarp extract is particularly effective against Escherichia coli, Citrobacter freundii, and Klebseilla pneumoniae. However, the extract Punica granatum (pericarp and juice) revealed broad-spectrum antibacterial activity with an inhibitory diameter zone size of 11 0.9 mm to 29 1.12 mm against β-lactamase generating methicillin resistant Staphylococcus aureus (MRSA) species.These results were similar in both of agar diffusion and MIC methods. From the above study, it can be concluded that Algerian pomegranate extracts possess remarkable antibacterial activity. This result could be related to the presence of bioactive metabolites in this fruit. Therefore, intensive future studies should be performed to characterize the antibacterial components that are behind for this biological property.

The Rhodamine B-encrypted Vipericidin Peptide, RhoB-Ctn[1-9], Displays In vitro Antimicrobial Activity Against Opportunistic Bacteria and Yeasts

Crotalicidin (Ctn), a snake venom cathelicidin-related antimicrobial peptide, is a 34-residue-long linear lysine-rich vipericidin obtained from the South American rattlesnake, Crotalus durissus terrificus. Ctn contains tandem repeats of nine amino acid residues (1KRFKKFFKK9 and 16KRLKKIFKK24; consensus: 1KRhKKhFKK9, h = hydrophobic amino acid) as an integral part of its structure. The aim of this study was to evaluate the antimicrobial activity of the encrypted vipericidin nonapeptide KRFKKFFKK, designated as Ctn[1-9], and its structural analogue, rhodamine- B‒conjugated Ctn[1-9], designated as RhoB-Ctn[1-9]. The susceptibility of representative pathogenic bacteria and yeasts to antimicrobial agents was determined using the broth microdilution minimum inhibitory concentration (MIC) method. Cytotoxicity was estimated using a hemolytic assay. The accumulation of RhoB-Ctn[1-9] in microbial cells was observed by fluorescence microscopy. The antimicrobial synergism of RhoB-Ctn[1-9] with antimicrobials was evaluated using a checkerboard analysis. RhoB-conjugated Ctn[1-9] displayed selective antimicrobial activity against infectious gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, and pathogenic species of Candida with low hemolytic effects on human erythrocytes which were not observed with unconjugated Ctn[1-9]. RhoB-Ctn[1-9] could permeate cell membranes and accumulate intracellularly in microbial cells. RhoB-Ctn[1-9] exhibits synergistic effects when used with antibiotics or antifungal agents and reduced the MICs of the peptide and antimicrobials. These findings indicate the potential of crotalicidin-related short peptides as structural motifs for the diversification of biological functionalities. Further, they set the stage to investigate the molecular mechanisms by which chemically modified vipericidin repeats modulate cell fate.

ChromagarTM Col-Apse for Detection of Colistin Resistance in Clinical Isolates of Multidrug Resistant Gram Negative Bacilli.

To determine the diagnostic accuracy of CHROMagarTM COL-APSE, for detection of colistin resistance in clinical isolates of multi drug resistant (MDR) gram negative bacilli (GNB). Cross-sectional validation study. Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan from February 2019 to August 2019. Total 96 MDR-GNB in clinical isolates were included. Isolates were identified using gram stain, catalase, oxidase, API 20E and API 20NE. After taking approval from Institutional Ethical Review Committee, colistin susceptibility was determined simultaneously by CHROMagarTM COL-APSE (using 1x105 CFU/ml inoculum) and Broth Micro Dilution (BMD) Minimum Inhibitory Concentration (MIC) method as per CLSI. EUCAST guidelines were followed for interpretation of susceptibility profile. Results were validated with gold standard test, i.e. BMD. Out of 96 MDR clinical isolates, the distribution was K. pneumoniae n=63, E. coli n=18, A. baumannii n=11, C. freundii n=3, and E. cloacae n=1. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CHROMagarTM COL-APSE for detection of colistin resistance, keeping BMD-MIC method as gold standard, was 97.96%, 97.87%, 97.96%, 97.87% and 97.92%, respectively. CHROMagarTM COL-APSE can be used as screening agar by direct streaking of specimen as well as diagnostic for detection of colistin resistance by the use of standardised inoculum. It can be used as a critical time saving method for colistin resistance detection in absence of expertise or manpower required for BMD as well as the cost required for genetic sequencing to detect MCR genes. Key Words: Multi drug resistant (MDR), Gram negative bacilli (GNB), Colistin resistance, CHROMagarTM COL-APSE.

SCREENING OF ANTIMICROBIAL ACTIVITY OF VARNYA LEPA LOTION - A POLYHERBAL FORMULATION

Objective: To screen the antimicrobial activity of Varnya lepa lotion against skin infecting organisms like Staphylococcus aureus and Staphylococcus epidermis. In Ayurvedic literature, Varnya lepa is one of formulation which includes seven drugs like Raktachandan, Manjista, Kustha, Lodhra, Priyangu, Vatankura and Masura. It is mainly indicated for melasma, enhances complexion and hyperpigmentation. Methods: The antimicrobial activity of Varnya lepa lotion was testing by using Agar well diffusion method/ Cup-plate method and Minimum inhibitory concentration(MIC). Results:Through the Disc diffusion method, Varnya lepa lotion has shown no antibacterial activity but by MIC method has minimum antibacterial activity against Staphylococcus aureus and Staphylococcus epidermis organisms. Conclusion: As herbal products are growing in the market tremendously and concerns surrounding their safety are also increasingly recognised. In this article, it is concluded that Varnya lepa lotion was having a minimum antibacterial effect against the organisms like Staphylococcus aureus and Staphylococcus epidermis and would protect skin from different infections.

2-Aminoselenazoles and 2-aminothiazoles: One-pot synthesis and control of the fungus Colletotrichum lindemuthianum in common beans.

Anthracnose, caused by the fungus Colletotrichum lindemuthianum, increases losses in the production of common beans. As 1,3-diazoles can act against fungi by inhibiting the enzyme squalene epoxidase (SE), 2-aminoselenazoles and 2-aminothiazoles were synthesized and subjected to tests with the fungus. In addition, the interactions of the most promising substances with the enzyme SE were investigated in silico. Seventeen compounds (eight new) were prepared by a one-pot methodology. In vitro antifungal activities of these compounds against C. lindemuthianum were determined by the minimum inhibitory concentration (MIC) method. Most treatments differed from the control (water), and six azoles with the lowest MIC values underwent an assay employing common bean plants inoculated with the fungus. Among the best results were those from 2-(3-fluorophenyl)amino-4-phenyl-1,3-thiazole (16; 2857 μg mL-1 ), which reduced the severity of anthracnose in common beans to values statistically comparable to the commercial fungicide thiophanate-methyl (700 μg mL-1 ). The in silico affinity of compound 16 for SE was statistically equal to those calculated for several inhibitors of this enzyme. The results suggested that 2-(3-fluorophenyl)amino-4-phenyl-1,3-thiazole (16) could be considered a potential fungicidal lead compound for further structural optimization, which according to the in silico study acts via SE inhibition. © 2022 Society of Chemical Industry.

COLISTIN AGAR; EVALUATION OF A NOVEL DIAGNOSTIC APPROACH TO DETECTION OF COLISTIN RESISTANCE

Objective: To determine the diagnostic accuracy of Colistin agar for detection of Colistin resistance in clinical isolates of MultiDrug Resistant Gram-Negative Bacilli.
 Study Design: Cross-sectional validation study.
 Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Feb to Aug 2019.
 Methodology: A total of 100 Multi-Drug Resistant Gram-Negative Bacilli in clinical isolates were included. Isolates were identified using Gram stain, Catalase, Oxidase, API 20E, and API 20NE. After approval from the institutional ethical review committee, Colistin susceptibility was determined simultaneously by Colistin agar and Broth Micro Dilution Minimum Inhibitory Concentration method as per CLSI. For susceptibility criteria, EUCAST guidelines were followed. Results were validated with the gold standard test, i.e., Broth Micro Dilution.
 Results: Out of 100 Multi-Drug Resistant clinical isolates, the distribution was K. pneumoniae n=60, E.coli n=16, A. baumannii n=11, C. freundii n=8, and E. cloacae n=5. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of Colistin agar for detection of Colistin resistance, keeping Broth Micro Dilution Minimum Inhibitory Concentration method as the gold standard was 96.67%, 97.14%, 93.55%, 98.55%, and 97%, respectively.
 Conclusion: Colistin agar has excellent diagnostic accuracy for the detection of colistin resistance with standardized inoculum density. Due to its ease of use, cost-effectiveness, and accurate results, it can be used in lab setups deficient in manpower and advanced equipment for Broth Micro Dilution or genetic sequencing.

Design, preparation, biological investigations and application of a benzoguanamine-based nickel complex for the synthesis of benzimidazoles

The new magnetic-supported benzoguanamine-based nickel complex was prepared, characterized by various procedures and used as a capable heterogeneous nano-catalyst for the synthesis of diverse 2-phenyl-1H-benzo[d]imidazoles from the reaction o-phenylenediamine (PhenDA) with various aldehydes in chloroform at reflux conditions. Then, the biological (anti-oxidant, anti-bacterial and anti-cancer) activities of the nickel complex were studied. The antioxidant properties of the complex were investigated using the DPPH assay at six different concentrations. The results show that the antioxidant properties of the catalyst are directly proportional to its concentration, and as the concentration increases, its antioxidant properties also increase. In addition, results from the two antibacterial assays of minimum inhibitory concentration (MIC) and disk diffusion methods (DDM) showed that the catalyst could impair the growth of both the gram-positive and the gram-negative bacteria in all tested concentrations. In agreement with MIC, the inhibitory activity of catalyst on S. aureus was more than that on E. coli in disk diffusion method. Incidentally, the anticancer (proliferative) activity of the Ni-complex was investigated against the MG63 cell line. The ratio of cell viability under the catalyst treatment has shown a considerable decrease compared to Cisplatin as the positive control confirming its anticancer property. The IC50 value determined the growth inhibition of cancer cells, indicating that the compound concentration was associated with the half inhibition of the cancer cell growth.

The chemical composition and antibacterial activity of a methanolic extract of Satureja khuzistanica

In the present study, the metabolite profiling of methanolic extract from aerial parts of Satureja khuzistanica Jamzad, as an endemic medicinal plant from Iran, was evaluated using HPLC-PDA-ESI. Then, the main compound from the extract was isolated and purified by using extensive chromatographic techniques. In addition, the structure of the isolated compounds was elucidated using 1D, 2D NMR, and MS spectrometry, upon which 22 compounds were identified. The antibacterial activity of diosmetin 7-rutinoside (6) and linarin (13) in combination with carvacrol as a major compound of the essential oil was tested against Pseudomonas aeruginosa and Staphylococcus aureus through disc diffusion and minimum inhibitory concentration methods. The results indicated that the linarin, when mixed with carvacrol as the main compounds in the essential oil of the plant, has a satisfactory activity against both Pseudomonas aeruginosa and Staphylococcus aureus with MIC values of 0.16 and 0.18 µg/mL, respectively. Further, the fractional inhibitory concentration (FIC) index indicated that this compound had synergism with carvacrol.

Association of the essential oil of Cymbopogon citratus (DC) Stapf with nystatin against oral cavity yeasts.

Oral thrush or candidiasis is a fairly common infectious fungal disease that is mainly caused by species of the genus Candida spp. In this work, we evaluated the antifungal activity of the essential oil of Cymbopogon citratus (DC) Stapf (lemongrass) and its combination with nystatin against oral cavity yeasts. The oil was extracted by the steam distillation method, and its constituents were quantified. The yeasts were identified using MALDI-TOF MS. The sensitivity to the essential oil and its association with nystatin was verified by the minimum inhibitory concentration (MIC) and checkerboard methods. In the essential oil samples, there were 84.53% of citral. A total of 64.77% of strains were identified as Candida albicans. On susceptibility tests, 83.55% of the yeast isolates were inhibited in concentrations of ≥16 µg/mL of nystatin. C. citratus's oil was capable of inhibiting and killing all the isolates tested with concentrations that varied from 0.137 to 2.2 mg/mL. The association of oil and nystatin had an additive effect on more than 78% of the strains. The association of this herbal drug with nystatin potentialized the antifungal effect on yeast samples isolated from the oral cavity of oncologic patients.

Susceptibility Profile and Clinical Response of Fosfomycin and Other Antibiotics against Multidrug Resistant Gram Negative Urinary Isolates: A Cross-sectional Study

Introduction: Irrational use of antibiotics to treat Urinary Tract Infections (UTI) has led to the development of Multidrug Resistant (MDR) bacteria in both community as well as the hospital settings. Fosfomycin has emerged as a novel therapeutic option to treat these UTI patients along with empirically used routine antibiotics. Aim: To assess the sensitivity, molecular resistance mechanisms and clinical response of fosfomycin along with other urinary antibiotics like nitrofurantoin, colistin, and imipenem. Materials and Methods: It was a cross-sectional observational study from July 2018 to June 2019 in SGPGIMS, Lucknow, India. Stream urine samples of 24,782 patients were collected with clinical suspicion of UTI. The antibiotics were tested by disc diffusion and Minimum Inhibitory Concentration (MIC) methods. Genotypic analysis was done for testing resistance mechanisms in fosfomycin resistant isolates. Statistical tests were performed using Statistical Package for the Social Sciences (SPSS) software for Windows version 14.0. Results: Out of the 24,782 urine samples, 2,776 (11.2%) showed significant growth of pathogens ,with 334 drug resistant isolates among them. Gram negative bacilli 1846 (66.50%) was the most predominantly isolated pathogen in the cultures. Among the 334 drug resistant specimens, Escherichia coli {124 (37.13%)} were maximum in number. Total 79.6% (266/334) of the isolates were sensitive to fosfomycin including 89% (110/ 124) of E. coli, and 91.3% (105/115) of K.pneumoniae isolates. Colistin showed sensitivity in 87% (108/124) of the E.coli isolates; followed by Imipenem in 49% (61/124) and nitrofurantoin in 37% (46/124) of the isolates. Fos A genes were found to be the most prevalent in Fosfomycin resistant. About 41% of the patients showed favourable outcome and were cured with initiation of treatment as per sensitivity pattern. Conclusion: Fosfomycin has emerged as a safer option in MDR urinary isolates as compared to other urinary antibiotics including colistin. The drug needs to be more widely studied for its possible pharmacokinetics and dynamics as well as it’s possible implications in health care settings and patient management.

Anticancer, Antibacterial, Antioxidant, and DNA-Binding Study of Metal-Phenalenyl Complexes.

Phenalenyl (PLY)-based metal complexes are a new addition to the metal complex family. Various applications of metal-based phenalenyl complexes (metal-PLY) have been reported, such as catalyst, quantum spin simulators, spin electronic devices, and molecular conductors, but the biological significance of metal-PLY (metal = Co(II), Mn(III), Ni(II), Fe(III), and Al(III)) systems has yet to be explored. In this study, the anticancer properties of such complexes were investigated in ovarian cancer cells (SKOV3 and HEY A8), and the cytotoxicity was comparable to that of other platinum-based drugs. Antibacterial activity of the metal-PLY complexes against both gram-negative (E. coli) and gram-positive (S. aureus) bacteria was studied using a disk diffusion test and minimum inhibitory concentration (MIC) methods. All five metal-PLY complexes showed significant antibacterial activity against both bacterial strains. The antioxidant properties of metal-PLY complexes were evaluated following the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method and were acceptable. The DNA-binding properties of these metal-PLY complexes were investigated using absorption spectroscopy, fluorescence spectroscopy, viscosity measurements, and thermal denaturation methods. Experimental evidence revealed that the complexes bind to DNA through intercalation, and the molecular docking study supported this conclusion.

Antibacterial Effect of Turkish Black Cumin Seed Oil Against Pathogen Bacteria's

Black cumin seeds are used for medicinal and aromatic purposes in Turkey. Black cumin seed oil (BSCO) was provided from a local producer. BCSO was extracted by cold-pressing method. Antibacterial effect of BCSO was investigated against B. cereus (ATCC 10876), L. monocytogenes (ATCC 19115), E. coli (ATCC 25922), Salmonella Thypimurium (ATCC 14028) and S. aureus (ATCC 25923) by minimum inhibitory concentration (MIC) method. MIC values were determined according to micro tube dilution method. BCSO had antibacterial effect against B. cereus and S. aureus and didn’t have antibacterial effect against other bacterias. B. cereus and S. aureus are Gram (+) and others are Gram (-). In various studies, it had been found that Gram (+) bacterias are less resistance to aromatic oils. Fatty acid composition of BCSO was investigated for additional information of material and major fatty acids of BCSO are linoleic acid, oleic acid and palmitic acid. As a results, study suggests that cold-pressed BCSO can be used for its functional property. Pract?cal Appl?cat?ons Black seed oil is widely used in ethnopharmacology. It is marketed as a treatment agent for many mild diseases in the shops called "Aktar" in Turkish culture and it finds a response by the public. However, its use in industry is limited due to its pungent odor and taste. In this study, the functional properties of black cumin oil were investigated.

Chemical characterization and bioactive potential of Thymus×citriodorus (Pers.) Schreb. preparations for anti-acne applications: Antimicrobial, anti-biofilm, anti-inflammatory and safety profiles

Ethnopharmacological relevanceThymus × citriodorus (Pers.) Schreb. is an interspecific hybrid between Thymus pulegioides and Thymus vulgaris, known for its pharmacological activities as diaphoretic, deodorant, antiseptic and disinfectant, the last mostly related with its antimicrobial activity. The folk use of other extracts, as hydrolates, have also been disseminated, as regulators of oily skin with anti-acne effect. Aim of the studyWe aimed to evaluate the anti-acne potential of two Thymus x citriodorus (TC) preparations, the essential oil (EO) and the hydrolate, to be used as active ingredients for skin applications. Specifically, we intend to validate their anti-acne potential by describing their activity on acne related bacteria, bacterial virulence, anti-oxidant and anti-inflammatory potential, and biocompatibility on inflammatory cells. Additionally, we aimed to report their ecotoxicity under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), thus focusing not only on the consumer, but also on environmental safety assessment. Materials and methodsMinimum inhibitory concentration (MIC) against C. acnes, S. aureus and S. epidermidis was evaluated. Minimum lethal concentration (MLC) was also determined. The effect on C. acnes biofilm formation and disruption was evaluated with crystal violet staining. Anti-inflammatory activity was investigated on LPS-stimulated mouse macrophages (RAW 264.7), by studying nitric oxide (NO) production (Griess reagent) and cellular biocompatibility through MTT assay. In-vitro NO and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging potential were also evaluated. The ecotoxicity was evaluated using Daphnia magna acute toxicity assays. ResultsEO presented direct antimicrobial activity, with visual MICs ranging from 0.06% for S. epidermidis and C. acnes to 0.125% for S. aureus. MLCs were higher than the obtained MICs. Hydrolate revealed visual MIC only for C. acnes. TC essential oil was effective in preventing biofilm formation and disrupting preformed biofilms even at sub-inhibitory concentrations. Hydrolate showed a more modest anti-biofilm effect. Regarding anti-inflammatory activity, TC hydrolate has a higher cellular biocompatibility. Still, both plant preparations were able to inhibit at least 50% of NO production at non-cytotoxic concentrations. Both EO and hydrolate have poor anti-oxidant activities. Regarding the ecotoxicity, TC essential oil was classified under acute 3 category, while the hydrolate has proved to be nontoxic, in accordance to the GHS. ConclusionsThese results support the anti-acne value of different TC preparations for different applications. TC hydrolate by presenting higher biocompatibility, anti-inflammatory potential and the ability to modulate C. acnes virulence, can be advantageous in a product for everyday application. On the other hand, EO by presenting a marked antimicrobial, anti-biofilm and anti-inflammatory activities, still with some cytotoxicity, may be better suited for application in acute flare-ups, for short treatment periods.

Green approach to synthesize MnxZn1-xO nanocomposite with enhanced photocatalytic, fluorescence and antibacterial activity

Green approach to synthesize MnxZn1-xO [x ​= ​0.05 (MNZ†), 0.1 (MNZ1), 0.2 (MNZ2), 0.3 (MNZ3), and 0.4 (MNZ4)] nanocomposites via co-precipitation method under the controlled condition at pH∼8–9 and its application was found in multidimension like photocatalytic, fluorescence and antibacterial activity. The X-ray powder diffraction (XRD), Furrier Transform Infrared (FT-IR), Scanning electron microscopy (SEM), UV–Vis absorption and Fluorescence spectroscopy techniques were used for the characterization of the prepared nanocomposite. The most thrilling phenomena is that MNZ catalyst have promising fluorescence characteristics with contains mixture of Mn(II)/Mn(III) and also good agreement with XRD, which differ from other Mn based ZnO. The result shows that the MnxZn1-xO (x ​= ​0.1) (MNZ1) catalyst exhibits remarkable photo catalytic activity (rate k ​= ​61.88 ​× ​10−3min−1) for photo-oxidation of Naphthol Orange (NO) under sunlight irradiation compared to other compositions of MNZ and ZnO. The optical band gap of MNZ1 was found 2.85eV which suggest that it’s an excellent photocatalyst under sunlight and shows outstanding reusability without any loss of activity. The phase structure of MNZ1 was Wurtzite type hexagonal and the average crystallite size was 16.41±1nm at [101] measured from Scherrer equation. The grain size of MNZ1 was found to be 100±5nm at 50KX and it looks flex type shape. It also shows excellent antibacterial activity against Gram-positive bacteria and Gram-negative bacteria by agar well diffusion, Minimum Inhibitory Concentration (MIC) methods and found that MNZ1 has good antibacterial activity against S. aureus compared with its parent ZnO and MnCl2.

New approach to treat methicillin resistant Staphylococcus aureus with the application of boric acid

Antibiotic resistance is a global concern and a heavy burden worldwide. This work aims to treat Methicillin-Resistant Staphylococcus Aureus with an emerging formulation strategy. A new strategy was applied through the synthesis of a highly potent film through the combination of boric acid (BA) and cefotaxime (CTX) in polyvinyl alcohol (PVA) or ethyl cellulose (EC) to combat microbial resistance.The antibacterial activity of the developed formulations was studied against methicillin-susceptible Staphylococcus aureus MSSA, (ATCC® 25923™), oxacillin sensitive S. aureus OSSA (ATCC® 29213™) and methicillin-resistant S. aureus, MRSA (ATCC® 43300™) by Kirby Bauer disc diffusion tests and minimum inhibitory concentration (MIC) methods. Fractional inhibitory concentration (FIC) indices demonstrate the significant synergistic effect and a 15 fold increase in antibacterial activity against MRSA (ATCC® 43300™) when CTX was delivered from the cross-linked PVA or EC film containing BA. The combinations of CTX with any of the β-lactamase inhibitors including clavulanate, sulbactam, and tazobactam did not show any antibacterial activity against MRSA. This novel finding suggests that the use of BA in combination with cefotaxime will substantially improve the efficacy of drugs against multi-drug resistant strains.

Molecular Confirmation of Vancomycin-Resistant Staphylococcus aureus with vanA Gene from a Hospital in Kathmandu.

Staphylococcus aureus, a commensal on the skin and in the nasal cavity of humans, is one of the most serious cases of nosocomial infections. Moreover, methicillin-resistant S. aureus (MRSA) is a leading cause of morbidity and mortality worldwide. For the treatment of MRSA infections, vancomycin is considered as a drug of choice. However, the emergence of vancomycin resistance among MRSA isolates has been perceived as a formidable threat in therapeutic management. To estimate the rate of vancomycin-resistant S. aureus (VRSA) and to detect the vancomycin-resistant genes, namely, vanA and vanB, among the isolates, a hospital-based cross-sectional study was conducted from July to December 2018 in Annapurna Neurological Institute and Allied Science, Kathmandu, Nepal. S. aureus was isolated and identified from different clinical samples and processed for antibiotic susceptibility testing by the modified Kirby–Bauer disc diffusion method. The screening of MRSA was performed as per Clinical and Laboratory Standard Institute (CLSI) guidelines. VRSA was confirmed by the minimum inhibitory concentration (MIC) method by employing E-test strips. All the phenotypically confirmed VRSA were further processed to detect the vanA and vanB gene by using the conventional polymerase chain reaction (PCR) method. A total of 74 (20.3%) S. aureus were isolated, and the highest percentage of S. aureus was from the wound samples (36.5%). Of 74 S. aureus isolates, the highest number (89.2%) was resistant to penicillin, and on the other hand, linezolid was found to be an effective drug. Likewise, 45 (60.81%) were found to be MRSA, five (11.11%) were VRSA, and 93.2% of S. aureus isolates showed an MAR index greater than 0.2. Two VRSA isolates (40%) were positive for the vanA gene. The higher prevalence of MRSA and significant rate of VRSA in this study recommend routine surveillance for the MRSA and VRSA in hospital settings before empirical therapy.

Novel transition metal complexes of 5-(2-phenyl-1H-benzo[d]imidazol-1-yl)quinolin-8-ol as active pharmacophore: Experimental and computational explorations

l New ligand derived from benzimidazole and 5-chloro-8-hydroxy quinoline, and its tansition metal complexes have been synthesized. l Characterized by 1 H NMR, IR, mass spectroscopy, XRD, elemental analysis and DFT methods. l In vitro antimicrobial activity of ligand and its complexes were determined. l Molecular docking and ADMET predictions of metal complexes shown as promising lead-like characters. A novel 5-(2-phenyl-1H-benzo[d]imidazol-1-yl)quinolin-8-ol ligand (PBIQ) ligand was used to synthesize a series of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes. Elemental analysis, FTIR, 1H NMR, UV-Visible and mass spectra were utilized to characterize the newly synthesized ligand and its transition metal complexes. The antimicrobial activity of the ligand and complexes were evaluated against four bacterial and one fungal strain using the minimum inhibitory concentration method (MIC). The minimum inhibition concentration observed was compared against the standard antibiotic rifampicin and the antifungal drug fluconazole. The studies revealed that Cu(II) and Zn(II) complexes are more effective against tested bacterial and fungal strains compared to the ligand and other complexes. Molecular docking techniques revealed that the Cu(II)-PBIQ complex associated with the target protein (PDB ID: 4HL2 ) had a greater binding affinity with π-σ, π-alkyl and hydrophobic interactions. Density function theory (DFT) calculations were applied to evaluate the optimized geometrical structures and to calculate the global reactivity descriptors of the more active Cu(II) and Zn(II) complexes. Besides, the in-silico pharmacokinetics showed that all the examined metal complexes compounds obeyed Lipinski's Rule of five with one violation.

BACTERIAL INHIBITORY EFFECT OF ALGERIAN POMEGRANATE (Punica Granatum L.) EXTRACTS (PEEL, JUICE, AND SEED) AGAINST MULTIDRUG RESISTANT BACTERIA

Punica granatum L. (pomegranate) is known popularly by its nutritional values and healthy benefits. The current study is aimed the evaluation of antibacterial effects of Punica granatum fruit extracts that cultivated in Algeria against environmental and clinical isolates of β-lactamase producing methicillin resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase ESBL-producing Enterobacteriaceae by using agar diffusion methods and minimum inhibitory concentration (MIC)-determination. Moreover, the extracts were investigated for their phenolic content by the Folin-Ciocalteu method. The quantitative assays of total polyphenols revealed a richness of the different pomegranate extract in polyphenols, peel and seed ethanol extracts contain the highest values (880.06 ± 11.2 mg GAE/100 g and 1160.1 ± 45.20 mg GAE/100 g, respectively). Flavonoid contents were high in both of acetone, ethanol extracts of peel, followed by ethanol, and acetone extracts of juice. According to the disc diffusion data, all phenolic extracts had a bacterial inhibitory effect against all extended-spectrum beta-lactamase ESBL-producing Enterobacteriaceae with a strong inhibitor with MIC 512 g/mL strength. The pericarp extract is particularly effective against Escherichia coli, Citrobacter freundii, and Klebseilla pneumoniae. However, the extract Punica granatum (pericarp and juice) revealed broad-spectrum antibacterial activity with an inhibitory diameter zone size of 11 0.9 mm to 29 1.12 mm against β-lactamase generating methicillin resistant Staphylococcus aureus (MRSA) species.These results were similar in both of agar diffusion and MIC methods. From the above study, it can be concluded that Algerian pomegranate extracts possess remarkable antibacterial activity. This result could be related to the presence of bioactive metabolites in this fruit. Therefore, intensive future studies should be performed to characterize the antibacterial components that are behind for this biological property.

Phytochemicals and Bioactivities of Syzygium filiformevar. filiforme

Syzygium filiforme var. filiforme is a plant variety from dicotyledonous plant family (Myrtaceae). Phytochemical studies on S. filiforme var. filiforme stem bark have successfully isolated and characterized arjunolic acid (1), alphitolic acid (2), betulinic acid (3), ursolic acid (4), ursolic acid 3-methyl ester (5), β-sitosterol (6) and stigmasterol (7). The inhibitory activities against free radical, starch, and bacteria for major compounds were tested by using DPPH, α-glucosidase and minimum inhibitory and bacterial concentration assays, respectively. No promising antioxidant activity was shown on tested samples except methanolic crude extract. For antidiabetic activity, methanolic and dichloromethane crude extracts displayed potent activity compared to 1-deoxynojirimycin. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) assays for antibacterial activity were evaluated on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. All crude extracts and major compounds displayed weak and no promising activities for MIC method, respectively. Meanwhile, for MBC method, hexane crude extract and compound 1 showed inhibition against B. subtilis.