Antibacterial Activity of Lawsonia inermis Leaf Extracts against Multidrug-resistant Pseudomonas aeruginosa from Infected Wounds

Background: Wound infection comprises numerous different organisms that have the ability to surface colonization of wounds. Multidrug-resistant Pseudomonas aeruginosa is one of the pathogenic bacteria associated with wound infections. Aim: This study isolated and identified multidrug-resistant Pseudomonas aeruginosa from infected wounds and determine the antibacterial activity of Lawsonia inermis leaf extracts against it. Design: This is a Clinical and laboratory-based study involving patients with defined cases of wound infections. Place and Duration of Study: This study was conducted in the Microbiology (Bacteriology) laboratory of Specialist Hospital, Bauchi, Nigeria, from February to November 2021. Methods: Twenty-eight (28) Pseudomonas aeruginosa isolates were recovered from 179 wound swabs using standard laboratory procedures and were screened for multidrug-resistant patterns according to the Kirby-Bauer disc diffusion method. Antibacterial efficacy of the aqueous, ethanolic, and methanolic leaf extracts of Lawsonia inermis was tested against the multidrug-resistant isolates using agar well diffusion techniques. The zone of inhibition was measured and the differences between means were statistically analyzed (p<0.05). Results: A total of twenty-eight (28) multidrug-resistant Pseudomonas aeruginosa were confirmed, showing resistance to Amoxicillin (64.3%), Ceftazidime (85.71%), and Cefotaxime (78.57%) but sensitivity to Imipenem (95.5%). The phytochemical screening revealed the presence of flavonoids, glycosides, saponins, steroids, and tannins among others. MDR P. aeruginosa was inhibited at varied concentrations of the extracts with the diameter mean zone of inhibition increasing as the concentration increased. The Methanol extracts showed the highest antibacterial activity against MDR P. aeruginosa with a mean zone of inhibition of 9.500±0.288mm at 400mg/ml. Conclusion: These results indicated that Lawsonia inermis leaf extracts possess antibacterial activities on Multidrug-resistant Pseudomonas aeruginosa which could be a good source for the production of plant-based antibacterial drugs., although somewhat less than the synthetic standard drugs (Imipenem) having a mean of 13.83±0.288mm.

Synthesis, spectral characterization, anti-bacterial, cytotoxic evaluation and docking studies of new urea and thiourea derivatives

Isoniazid is one of the main API’s used in the combination treatment of tuberculosis recommended by the WHO. Urea and its derivatives are an important class of heterocyclic compounds that possess a wide range of therapeutic and pharmacological properties, while thiourea is an organosulphur compound in that it resembles urea except that the atom oxygen has been replaced by a Sulphur atom, but the properties of urea and thiourea are significantly different. The current work concerns the synthesis of a new class of urea and thiourea derivatives of isoniazid with various isocyanates and isothiocyanates in the presence of trimethylamine. The IR and NMR spectral data were performed for the urea and thiourea derivatives of the compounds [(3c & 3f) & (3d & 3e)], respectively. Molecular docking studies of the compounds (3a-h) revealed the binding mode involved in the active site of DNA gyrase. The synthesized urea and thiourea derivatives of isoniazid with various isocyanates and isothiocyanates were tested for their antibacterial activity against gram-positive and gram-negative bacteria using the “disc diffusion method”. Of all compounds tested, the urea derivatives (3a &3d), the thiourea derivatives (3e & 3g) showed more potent activity than the other compounds. The MTT assay revealed concentration dependent cytotoxic effects over a concentration range 25-200 µg/mL.

Isolation of Enterococcus spp. in various clinical sample and their antimicrobial resistant pattern with MIC of vancomycin in patient attending tertiary care centre, RIMS, Ranchi, Jharkhand

Introduction- Enterococci are part of normal intestinal flora of humans and animals but have also emerged as important pathogens responsible for serious infections in hospital and community acquired infections.it is second most common cause of nosocomial infections in gastrointestinal tract, wound and genitourinary tract. To process all the clinicalAim- samples from various department in our hospital, for isolation of Enterococci spp. To speciate the isolates & to have resistance pattern of the isolates of vancomycin total 926 sample were collected from both outMaterial & Methods- patients and in patient in all clinical departments and transported to microbiology laboratory. specimens were processed by inoculating on to blood agar, MacConkey Agar, nutrient agar, potassium tellurite agar and incubated at 37°C for24-48 hr. Enterococci were identified by their typical arrangement in and salt tolerance test Gram stain, bile esculin test and biochemical tests. Antimicrobial susceptibility patterns were determined by performing Kirby-Bauer disc diffusion method and Minimum inhibitory concentration (MIC) values were identified by tube dilution methods. Result- a total of 926 sample, 645 (69.72%) were culture positive and 281 (30.28%) were culture negative. Among 645 culture positive cases, 81(12.55%) were Enterococcus faecalis. Antimicrobial susceptibility & MIC done as per standard protocols. The E. Faecalis showed 99% sensitive to Vancomycin. the resistance to vancomycin was 1% & further confirmed by MIC via tube dilution methods. In which MIC was ?32 ?g/ml in one isolate. About 8 of Enterococcal strains showed MIC of 0.0125?g/ml. species level identification of Enterococcus is important forConclusions- epidemiological study and also for analysis of drug resistant pattern. Effective detection of vancomycin resistance helps in reducing the morbidity and mortality of VRE in hospitalized patients

Molecular docking and Antibacterial activities of Cobalt (II) complexes derived from precursors of Hydrazones

The Schiff base ligands in their deprotonated forms have been utilized to synthesize thermodynamically and kinetically stabilized Cobalt(II) complexes. In the complexes, cobalt ion present is in distorted octahedral arrangement and is coordinated by four tridentate ligands in complexes. The synthesized Schiff base ligands coordinate with Cobalt (II) ion through four azomethine nitrogen atoms and two sulfur atoms developing a 6- membered chelate ring. Synthesized Cobalt(II) complexes via hexadentate ligands have been characterized thoroughly through various spectroscopic techniques like FT-IR, UV-Vis, 1HNMR, TGA, TEM, SEM, Particle size, Elemental analysis (C, H, N, Co, S) and conductivity measurements. All Cobalt(II) complexes have been evaluated for in vitro antimicrobial activity against isolated bacterial strains of E. coli (MTCC-1687), E. faecalis (MTCC-439), S. aureus (MTCC-737) and MR S. aureus (Indigenous). All Cobalt complexes show mild to moderate antibacterial activity. The MIC ranged from 50 µg/ mL to 3.125 µg/ mL. All Cobalt(II) complexes displayed in-vitro antibacterial activity against both gram-positive and gram-negative bacterial strains. It may be proved that the antibacterial activity of the complexes is related to the cell wall structure of the tested bacteria. In-vitro toxicity tests explained the Cobalt complexes were less cytotoxic than the Vancomycin drug on A431 cancer cell lines and the results explain that synthesized Cobalt complexes can act as potent antimicrobial agents and can be considered as a good drug candidate for medicinal chemistry researchers.

Biosynthesis of Silver Nanoparticles Using Tradescantia zebrina aqueous Leaf Extract and Their Antibacterial Activity

Biologically synthesized silver nanoparticles have emerged as one of the prime areas of investigation in recent years due to their wider application in biomedical and pharmaceutical sciences. In the present paper, we report the biosynthesis of silver nanoparticles using aqueous leaf extract of T. zebrina and its antibacterial activity against common human pathogenic bacteria such as Staphylococcus epidermidis, Staphylococcus aureus, Salmonella enterica, Escherichia coli and Bacillus cereus. The antibacterial activity of the biosynthesized silver nanoparticles were compared with amikacin which was used as the positive control. The results of the study revealed good zones of inhibitions of the nanoparticles against test organisms that were comparable to amikacin and hence has a great potential in the preparation of drugs used against bacterial diseases.

Comparison of two methods testing synergistic action of Reduning and cefoperazone sodium/sulbactam sodium on extensive drug resistant Acinetobacter bauman / 国际检验医学杂志

Objective To observe the results of broth dilution method and disc diffusion method to test the synergistic effect of Reduning and cefoperazone sodium / sulbactam sodium(SCF) on extensive drug resistant Acinetobacter bauman (XDR-AB) in vitro environment ,and compare their compliance to guide the clinical medication .Methods A total of 12 strains of XDR-AB from infec-tion patients in our hospital in 2015 were collected ,the strain was sub cultured .Firstly ,observe the minimum inhibitory concentra-tion (MIC) of SCF and Reduning on XDR-AB alone and in combination by broth dilution method .And then judge the synergy effects through calculation .Secondly ,the inhibition ring diameter and the synergy effects was detected using the disc diffusion meth-od .Results The MIC of Reduning and SCF in combination on XDR-AB was declined compared with them alone .The Fractional in-hibitory concentration of Reduning and SCF in combination on XDR-AB were equal or less than 0 .5 ,they had synergistic effect on XDR-AB .The inhibition ring diameter of Reduning was 10 mm tested by disk diffusion method .Different strains of XDR-AB on SCF bacteriostatic annulus diameter difference ,5 strains were 15 mm ,3 strains were 16 mm ,and 4 strains were 17 mm .Reduning and SCF appeared synergistic effect according to the inhibition ring diameter expanded when they effected on XDR -AB in combina-tion .Conclusion In vitro ,Reduning combined with SCF on XDR-AB has good synergistic effect .Compared with broth microdilution checkerboard dilution method ,disk diffusion method is more simple and convenient ,but it has a certain subjective on judging re-sults ,which is better to operate by experienced person .

Exploration of Phytochemical and Antibacterial Potentiality of Anagallis arvensis L. Extract against Methicillin-Resistant Staphylococcus aureus (MRSA).

Context: Anagallis arvensis L. (Scarlet pimpernel) was used to treatment of several ailments in several countries. Objective: The aim of this study was to evaluate the in vitro antimicrobial activity of leaf methanolic extract of A. arvensis against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). Methods: In this study A. arvensis leaf was shade dried, powdered and extract was made by using methanol. The antimicrobial activity of methanolic extract was investigated against clinical isolates of MRSA by both the disc diffusion method and the microbroth dilution method. Results: The result of disc diffusion method showed that the plant extract recorded different degrees of antibacterial activity on MRSA as evidenced by the inhibited zones. The MICs of the plant extract and vancomycin were >100 and 14.5±0.1 μg/mL, respectively. This results showed that the plant extract although have slightly effect on MRAS but it was not sufficient strong. Discussion and Conclusion: A. arvensis leaf extract has anti-MRSA properties, corroborating the traditional therapeutic uses of this plant, and can be used in the therapy of infectious diseases as well as an antimicrobial supplement in food industries.

Chemical composition and antimicrobial activities of leaves of sweet basil (Ocimum basilicum L.) herb.

Background: Leaves and flowering parts of Ocimum basilicum are believed to be rich of different phytochemicals and are traditionally used as antispasmodic, aromatic, carminative, digestive, galactogogue, stomachic, and tonic agents. Hence, the study was designed to evaluate the phytochemical constituents and antimicrobial activities of the leaves of sweet basil (O. basilicum) herb. Methods: The leaf extract was used for screening of phytochemicals. A small amount of the powdered leaves of the plant was subjected to hydrodistillation to extract the essential oil, and the components of the essential oil were evaluated by gas chromatography-mass spectroscopy instrument. The extract was tested in vitro for its antibacterial activity against two bacteria; Escherichia coli and Staphylococcus aureus and antifungal activity against two fungi; Aspergillus niger and Rhizoctonia bataticola by paper disc diffusion method. Results: Results revealed the presence of many phytochemicals such as alkaloids, tannins, flavonoids, cholesterol, terpernoids, glycosides, phenols, cardiac glycosides, carbohydrates, and phlobatannins. The essential oil extracted from the leaves of O. basilicum was found to have estragole (38.22%) as a major constituent followed by 1-isopropyl-4-methylenecyclohex-1-ene (11.10%). Tests of antimicrobial activity showed that the hydrodistilled oil was effective against all the tested bacterial and fungal strains. However, the crude extract was found not to have antimicrobial activity toward the tested bacteria and fungi. Conclusion: So, the study has showed that the observed antimicrobial effect of O. basilicum essential oil on the bacterial and fungal isolate, though in vitro appear interesting and promising. So, emphasize have to made on the antimicrobial activities of the plant during the time of drug extraction.

Evaluation of the capabilities of disc diffusion and Vitek2-compact GN13 methods for testing antimi-crobial susceptibility and screening of ESBLs Enterobacteriaceae clinical isolates / 中华微生物学和免疫学杂志

Objective To evaluate the capabilities of disc diffusion and Vitek2-compact GN13 methods for testing antimicrobial susceptibility of screening ESBLs ( extended-spectrumβ-lactamase) in En-terobacteriaceae clinical isolates.Methods A total of 93 Enterobacteriaceae strains were isolated from pa-tients with intra-abdominal infections in 21 hospitals during 2011 to 2012.The in vitro minimum inhibition concentration ( MIC ) values of ampicillin-sulbactam, piperacillin-tazobactam, ertapenem, ceftazidime, ceftriaxone, cefepime, imipenem, amikacin, ciprofloxacin and levofloxacin were determined by disc diffu-sion, Vitek2-compact GN13 and broth microdilution methods, respectively.Categorical agreement ( CA ) rates of disc diffusion and Vitek2-compact GN13 methods were determined by using broth microdilution meth-od as the reference method.The genes encoding ESBLs were screened in Escherichia coli (E.coli), Kleb-siella pneumoniae (K.pneumonia), Klebsiella oxytoca (K.oxytoca) and Proteus mirabilis (P.mirabilis) strains by using PCR analysis and gene sequencing.Disc diffusion and Vitek2-compact GN13 methods were used for the phenotypic confirmatory test of ESBLs and the sensitivity, specificity, positive predictive value and negative predictive value of the two tests were evaluated.Results The CA values of disc diffusion and Vitek2-compact GN13 methods for the 10 antibiotics were all >90% as compared with broth microdilution method.The major error (ME) rate for ertapenem was 3.2%and the very major error (VME) rates for am- picillin-sulbactam, ceftazidime and cefepime tests were all 2.2% by using Vitek2-compact GN13 method. The sensitivity, specificity, positive predictive value and negative predictive value of disc diffusion and Vitek2-compact GN13 methods in the phenotypic confirmatory test of ESBLs were 96.7%(29/30), 100%(20/20), 100%(30/30) and 95%(19/20), respectively.Conclusion Both disc diffusion and Vitek2-compact GN13 methods could be used for testing the antimicrobial susceptibility and the detection of ESBLs in Enterobacteriaceae clinical isolates with the advantage of accuarcy.Attention should be paid to the posibil-lity of oaurance of ME and VME when testing ertapenem, ampicillin-sulbactam, ceftazidime and cefepime by using Vitek2-compact GN13 method.

Antibacterial Activity of Different Solvent Extracts of Garlic Against New Strains of Pathogenic Bacteria: An in vitro Study.

The aqueous, ethanolic and methanolic extracts of garlic at different concentration were tested against two new strains of Bacillus species isolated from poultry farm. Among all the extracts of garlic tested, the ethanolic extracts showed increased inhibitory effect with maximum zone of inhibition of 21 mm against Bacillus licheniformis strain BIHPUR 0104. The aqueous extracts were more effective compared to methanolic extracts against Bacillus subtilis strain AK but methanolic extracts were showing more inhibitory effect than aqueous extracts against Bacillus licheniformis strain BIHPUR 0104. The ethanolic and methanolic extracts of garlic were active even at low concentration (5%) against Bacillus licheniformis strain BIHPUR 0104. Active compounds of garlic ethanol extracts were separated by Thin layer chromatography using Butanol:Ethanol (9:1 and 1:1) as eluting solvent and Rf values were calculated of the spots obtained. These results suggest that garlic is a potential spice to control pathogenic bacterial strain.

Isolation and characterization of potential antibiotic producing actinomycetes from water and sediments of Lake Tana, Ethiopia

To isolate, evaluate and characterize potential antibiotic producing actinomycetes from water and sediments of Lake Tana, Ethiopia. Methods: A total of 31 strains of actinomycetes were isolated and tested against Gram positive and Gram negative bacterial strains by primary screening. In the primary screening, 11 promising isolates were identified and subjected to solid state and submerged state fermentation methods to produce crude extracts. The fermented biomass was extracted by organic solvent extraction method and tested against bacterial strains by disc and agar well diffusion methods. The isolates were characterized by using morphological, physiological and biochemical methods. Results: The result obtained from agar well diffusion method was better than disc diffusion method. The crude extract showed higher inhibition zone against Gram positive bacteria than Gram negative bacteria. One-way analysis of variance confirmed most of the crude extracts were statistically significant at 95% confidence interval. The minimum inhibitory concentration and minimum bactericidal concentration of crude extracts were 1.65 mg/mL and 3.30 mg/mL against Staphylococcus aureus, and 1.84 mg/mL and 3.80 mg/mL against Escherichia coli respectively. The growth of aerial and substrate mycelium varied in different culture media used. Most of the isolates were able to hydrolysis starch and urea; able to survive at 5% concentration of sodium chloride; optimum temperature for their growth was 30 °C. Conclusions: The results of the present study revealed that freshwater actinomycetes of Lake Tana appear to have immense potential as a source of antibacterial compounds.

Screening antimicrobial activity of various extracts of Urtica dioica

Urtica dioica or stinging nettle is traditionally used as an herbal medicine in Western Asia. The current study represents the investigation of antimicrobial activity of U. dioica from nine crude extracts that were prepared using different organic solvents, obtained from two extraction methods: the Soxhlet extractor (Method I), which included the use of four solvents with ethyl acetate and hexane, or the sequential partitions (Method II) with a five solvent system (butanol). The antibacterial and antifungal activities of crude extracts were tested against 28 bacteria, three yeast strains and seven fungal isolates by the disc diffusion and broth dilution methods. Amoxicillin was used as positive control for bacteria strains, vancomycin for Streptococcus sp., miconazole nitrate (30µg/mL) as positive control for fungi and yeast, and pure methanol (v/v) as negative control. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the broth dilution method was used for the determination of the minimal inhibition concentration (MIC). The ethyl acetate and hexane extract from extraction method I (EA I and HE I) exhibited highest inhibition against some pathogenic bacteria such as Bacillus cereus, MRSA and Vibrio parahaemolyticus. A selection of extracts that showed some activity was further tested for the MIC and minimal bactericidal concentrations (MBC). MIC values of Bacillus subtilis and Methicillin-resistant Staphylococcus aureus (MRSA) using butanol extract of extraction method II (BE II) were 8.33 and 16.33mg/mL, respectively; while the MIC value using ethyl acetate extract of extraction method II (EAE II) for Vibrio parahaemolyticus was 0.13mg/mL. Our study showed that 47.06% of extracts inhibited Gram-negative (8 out of 17), and 63.63% of extracts also inhibited Gram-positive bacteria (7 out of 11); besides, statistically the frequency of antimicrobial activity was 13.45% (35 out of 342) which in this among 21.71% belongs to antimicrobial activity extracts from extraction method I (33 out of 152 of crude extracts) and 6.82% from extraction method II (13 out of 190 of crude extracts). However, crude extracts from method I exhibited better antimicrobial activity against the Gram-positive bacteria than the Gram-negative bacteria. The positive results on medicinal plants screening for antibacterial activity constitutes primary information for further phytochemical and pharmacological studies. Therefore, the extracts could be suitable as antimicrobial agents in pharmaceutical and food industry.

Urtica dioica u ortiga se utiliza tradicionalmente como medicina herbaria en el oeste de Asia. En esta investigación se estudia la actividad antimicrobiana de nueve extractos crudos de U. dioica, los cuales fueron preparados utilizando diferentes disolventes orgánicos y obtenidos a partir de dos métodos de extracción: el extractor Soxhlet (Método I), que incluía el uso de cuatro disolventes con acetato de etilo y hexano, y las particiones secuenciales (Método II) con un sistema de cinco disolventes (butanol). Las actividades antibacterianas y antifúngicas de extractos crudos fueron ensayados contra 28 bacterias, tres cepas de levadura y siete cepas fúngicas por la difusión en disco y el método de dilución en caldo. La amoxicilina se utilizó como control positivo para cepas de bacterias, vancomicina para Streptococcus sp., nitrato de miconazol (30μg/mL) como control positivo para los hongos y levaduras, y el metanol puro (v / v) como control negativo. El ensayo de difusión en disco se utilizó para determinar la sensibilidad de las muestras, mientras que el método de dilución en caldo se utilizó para la determinación de la concentración de inhibición mínima (CIM). El acetato de etilo y el extracto de hexano del método de extracción I (AE I y EH I) mostraron mayor inhibición contra algunas bacterias patógenas tales como Bacillus cereus, MRSA y Vibrio parahaemolyticus. Una selección de extractos que mostraron algún tipo de actividad se probó para el CIM y las concentraciones mínimas bactericidas (CMB). Los valores de CIM de Bacillus subtilis y de Staphylococcus aureus resistentes a la meticilina (MRSA) usando extracto de butanol mediante el método de extracción II (EB II) fueron: 8.33 y 16.33mg/ mL, respectivamente; mientras que el valor de MIC con el uso del extracto de acetato de etilo por el Método de extracción II (EAE II) para Vibrio parahaemolyticus fue 0.13mg/mL. Nuestro estudio mostró que el 47.06% de los extractos inhibieron bacterias Gram-negativas (8 de 17), y el 63,63% de los extractos también inhibieron bacterias Gram-positivas (7 de 11), además que estadísticamente la frecuencia de la actividad antimicrobiana fue de 13.45% (35 de 342), que de este porcentaje un 21.71% pertenece alos extractos de actividad antimicrobiana con el método de extracción I (33 de 152 de los extractos crudos) y un 6.82% del método de extracción II (13 de 190 de los extractos crudos). Sin embargo, los extractos crudos del método I exhibieron una mejor actividad antimicrobiana contra las bacterias Gram-positivas que las Gram-negativas. Los resultados positivos en la detección de plantas medicinales para la actividad antibacteriana constituye información primaria para la realización de nuevos estudios fitoquímicos y farmacológicos. Por lo tanto, los extractos podrían ser adecuados como agentes antimicrobianos en la industria farmacéutica y de alimentos.

Antimicrobial activity of zerumbone from zingiber zurumbet against staphylococcus epidermidis and aspergillus spp.

Zingiber zerumbet belongs to the family Zingiberaceae and is generally known as bitter ginger. Zerumbone one of the major compound from Zingiber zerumbet rhizomes. Zerumbone finds its usage in medicinal applications, food flavoring, condiments, fragrances etc. Bioactive compound zerumbone was isolated from the column chromatography eluting with hexane and ethyl acetate mixture varying the polarity. The compound zerumbone exhibited strong antibacterial activity against Staphylococcus epidermidis, moderate activity against Escherichia coli, moderate antifungal activity against Aspergillus oryza and Aspergillus niger.

Phytochemical screening and antibacterial activity of Gymnema sylvestre (Retz) R . Br ex. Schultes and Morinda pubescens J.E. Smith var. pubescens.

Two medicinal plants namely Gymnema sylvestre and Morinda pubescens var. pubescens were screened for potential antibacterial activity against Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi. The antibacterial activity was determined in petroleum ether, chloroform, acetone, methanol and aqueous extracts using disc diffusion method. The chloroform and methanol extract of leaf of Gymnema sylvestre showed highest inhibition against Escherichia coli and Klebsiella pneumoniae respectively; whereas, acetone extract of Morinda pubescens var. pubescens leaf exhibited maximum inhibition against Pseudomonas aeruginosa. Phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, tannins, and terpenoids. The results of these studies revealed most valuable information and also support the continued sustainable use of these plants in traditional systems of medicine.

In vitro interaction of certain antimicrobial agents in combination with plant extracts against some pathogenic bacterial strains

Objective: To evaluate the in vitro interaction between methanolic extracts of Terminalia catappa (Combretaceae) (T. catappa) and Carica papaya (caricaceae) (C. papaya) leaves and certain known antimicrobial drugs like penicillin G (P), ampicillin (AMP), amoxyclav (AMC), cephalothin (CEP), polymyxin B (PB), rifampicin (RIF), amikacin (AK), nilidixic acid (NA), gentamicin (GEN), chloramphenicol (C), ofloxacin (OF) against five Gram positive and five Gram negative bacteria.Methods:Evaluation of synergy interaction between plant extracts and antimicrobial agents was carried out using disc diffusion method. Results: The results of this study showed that there is an increased activity in case of combination of methanolic plant extracts and test antimicrobial agents. The more potent result was that the synergism between methanolic extract of C. papaya and antibiotics showed highest and strong synergistic effect against tested bacterial strains;though methanolic extract of C. papaya alone was not showing any antibacterial activity.Conclusions:These results indicate that combination between plant extract and the antibiotics could be useful in fighting emerging drug-resistance microorganisms.

Antimicrobial activity of leaf extracts of Justicia adhatoda L. in comparison with vasicine

Objective: To ascertain the antimicrobial activity of methanolic leaf extracts of Justicia adhatoda and vasicine against Staphylococcus aureus, Streptococcus pyogenes, Serratia marcescens, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Cryptococcus neoformans and Aspergillus flavus. Methods: The antimicrobial activity of the concentrated leaf extracts of J. adhatoda was evaluated by determination of the diameter of zone of inhibition against bacteria and fungi. 25μg ml-1 concentration was used to check the antimicrobial activity of plant extracts and vasicine. Minimum inhibitory concentrations and minimum microbicidal concentrations were determined against all the pathogens. Sensitivity of the pathogens was also checked with four standard antibiotics, ciprofloxacin and ofloxacin for bacteria and nystatin and amphotericin B for fungi. Results: The phytochemical studies revealed the presence of alkaloids in the extracts were active against both bacteria and fungi. Studies on the minimum inhibitory concentration of the extracts on the test organisms showed that the lowest minimum inhibitory concentration and minimum microbicidal concentrations were demonstrated against Serratia marcescens, Escherichia coli and Pseudomonas aeruginosa and the highest minimum inhibitory concentration was exhibited against Staphylococcus aureus, Streptococcuspyogenes, Klebsiella pnuemoniae. Among fungi Aspergillus flavus showed lowest minimum inhibitory concentration whereas Candida albicans and Cryptococcus neoformans showed highest minimum inhibitory concentration. Conclusion: The present study revealed that J. adhatoda has broad spectrum of antimicrobial activity and a potential source of antimicrobial agents that could be useful for chemotherapy and control of infectious diseases.

In vitro interaction of certain antimicrobial agents in combination with plant extracts against some pathogenic bacterial strains

Objective: To evaluate the in vitro interaction between methanolic extracts of Terminalia catappa (T. catappa) (Combretaceae) and Carica papaya (C. papaya) (caricaceae) leaves and certain known antimicrobial drugs like penicillin G (P), ampicillin (AMP), amoxyclav (AMC), cephalothin (CEP), polymyxin B (PB), rifampicin (RIF), amikacin (AK), nilidixic acid (NA), gentamicin (GEN), chloramphenicol (C), ofloxacin (OF) against five Gram positive and five Gram negative bacteria. Methods: Evaluation of synergy interaction between plant extracts and antimicrobial agents was carried out using disc diffusion method. Results: The results of this study showed that there is an increased activity in case of combination of methanolic plant extracts and test antimicrobial agents. The more potent result was that the synergism between methanolic extract of C. papaya and antibiotics showed highest and strong synergistic effect against tested bacterial strains;though methanolic extract of C. papaya alone was not showing any antibacterial activity. Conclusions: These results indicate that combination between plant extract and the antibiotics could be useful in fighting emerging drug-resistance microorganisms.

Phytochemical and antibacterial studies on Leucas vestita Wall ex Benth

Objective: In search of alternative herbal medicine for pathogenic microorganism variety of plant species have been identified. However, search of new species are still in progress to reduce the pressure on biological diversity and increase availability of organic compound. In the light of this the present work identified phytochemical property and antibacterial activity of Leucas vestita.Methods:The ethanol extract of L. vestita was used for this study. The phytochemicals present in the extract was identified and the antibacterial activity was tested through disc diffusion method. Results: The phytochemical studies revealed the presence of primary and secondary metabolites which ensuring their herbal properties. Antimicrobial activity showed increasing zone of inhibition with increasing concentration of the extract with Staphylococcus aureus, Bacillus subtilis, Enterobacter aerogenes, Klebsiella pneumoniae and Proteus mirabilis among the other microorganism. Larger zone of inhibition of 14mm was recorded for K. pneumoniae. Conclusions:The study suggests that this extract can be used as a medicine to control some of these pathogenic bacteria.

Antibacterial activity of Ascidian phallusia arabica against human clinical isolates.

Antibacterial activity of methanol and ethanol extracts of the ascidian, Phallusia arabica was evaluated by disc diffusion method against various human pathogen isolates. Two different concentrations (0.5and 1mg/ml) were analyzed. The crude methanol extract was more active exhibiting a broad-spectrum antibacterial activity than the ethanol extract against the pathogenic microbes tested. Maximum inhibition zone (12 mm) was observed against Pseudomonas aeruginosa in 1 mg ml-1 concentration crude methanol extract. The inhibition zone was 3 mm in Escherichia coli for ethanol extract of 0.5 mg ml-1 concentration. The ranges of inhibition zone in the tested extracts were lesser than the standard antibiotics used in all the strains. The MIC and MBC for methanolic extract tested in study inferred that the values range between 0.70-0.95 mg/ml and 0.85-1.1 mg/ml respectively.

Preliminary investigation on antimicrobial and proteolytic property of the epidermal mucus secretion of marine stingrays

Objective:To determine the antibacterial, antifungal, minimum inhibitory concentration (MIC) and the protease activity of the stingray mucus Dasyatis sephen (D. sephen) and Himantura gerrardi (H. gerrardi). Methods: Antimicrobial activity of crude aqueous, acidic and organic mucus extract was evaluated by disc diffusion method against human pathogens, MIC of the active samples were determined by spectrophotometric method and the protease activity which is responsible for the antimicrobial activity was determined by using zymogram method. Results:The crude acidic extracts of both the species showed antibacterial activity against Salmonella typhi (S. typhi), Klebsiella pneumoniae, Streptococcus aureus, Escherichia coli (E. coli), Vibrio cholerae (V. cholerae) and the acidic extracts of both the species exhibit antifungal activity against all the tested pathogens. Remaining extracts didn't show any inhibitory activity. The acidic extracts of H. gerrardi is significantly active against S. typhi, E. coli, V. cholerae, Trichophyton mentagrophytes (T. mentagrophytes), Alternaria alternaria (A. alternaria), Trichophyton rubrum (T. rubrum), Candida tropicalis (C. tropicalis) at the minimum concentration of 16μg/mL, but the acidic extract of D. sephen required 32μg/mL of protein to inhibit S.typhi, E. coli, Aspergillus niger (A. niger), penicillium sp, T. mentagrophytes, A. alternaria. Both the D. sephen and H. gerrardi shows the proteolytic activity above the molecular mass of> 66 KDa. The characterization of protease class using inhibitors showed the presence of both serine and metallo protease in the the samples. Conclusions:Protease activity present in the sting ray mucus is one of the key factor responsible for the antimicrobial activity and the results proved the role of mucus in the innate immunity.