Largest Inhibition Zone Research Articles

Antibacterial Effects of Steeped White Tea, Black Tea, and Green Tea against Streptococcus mutans and Plaque Accumulation

BACKGROUND: Tea is the most consumed beverage in the world after water. Tea (Camellia sinensis) is native to Southeast Asia and is now available in more than 30 countries. Tea has various health properties. Tea has an active component, namely catechins, which can inhibit the growth of Streptococcus mutans as a component of dental plaque formation. AIM: This study aims to determine the antibacterial effect of steeped white tea, black tea, and green tea on S. mutans and plaque accumulation. METHODS: The research used a quasi-experimental design with pre-test and post-test group design. The population was students of the Department of Dental Nursing. Purposive sampling technique is used with a sample size of 48 students who were divided into three parts of the sample group for the 2.5% concentration of tea mouthwash treatment. The analysis used paired t-test to see the antibacterial effect and differences in three-variable test followed by Kruskal–Wallis test. RESULTS: The results showed that the mouth rinses of steeped white tea, black tea, and green tea were effective in reducing S. mutans and plaque accumulation on teeth. There is a significant difference in the inhibition zone of S. mutans against the three types of tea, and white has the largest inhibition zone. As for plaque accumulation, there is no difference between the three types of tea. CONCLUSIONS: It can be concluded that mouth rinsing with steeping white tea, black tea, and green tea with a concentration of 2.5% has antibacterial properties that can inhibit S. mutans and plaque accumulation.

Antibacterial activity of mexican sunflower leaf Tithonia diversifolia (Hemsl.) A.Gray Aqueous extract against methicillin-resistant Staphylococcus aureus

The research of antibacterial activity of Mexican sunflower leaf Tithonia diversifolia (Hemsl.) A.Gray aqueous extract against Methicillin-Resistant Staphylococcus aureus (MRSA) was carried out. The research aimed to observe the antibacterial activity of Mexican sunflower leaves aqueous extract to inhibit the growth of MRSA with concentrations of 10, 20, 30, 40, and 50%. The extracts were obtained by the maceration method, and the antibacterial activity was tested using the agar well diffusion method. Characterization of Mexican sunflower leaves simplicia were obtained with water level 9%, water-soluble level 21,6%, ethanol-soluble level 10,3%, and total ash level 14,36%. Characterization of Mexican sunflower leaves aqueous extracts were obtained with water level 26,36%, water-soluble level 53,13%, ethanol-soluble level 26,36%, and total ash level 19,98%. Phytochemical screening revealed that aqueous extract of Mexican sunflower leaves contained secondary metabolites of alkaloids, flavonoids, tannins, and saponins. The largest inhibitory zone was shown at a 50% extract concentration with a diameter of 12,40 mm. The aqueous extract of Mexican sunflower leaves was capable to form the inhibition zone on the MRSA growth.

Seleção in vitro de bactéria autóctone com potencial probiótico para o peixe neotropical piauçu Megaleporinus macrocephalus

ABSTRACT The study aimed to isolate, identify, and apply in vitro tests on bacteria with autochthonous probiotic potential isolated from fifteen healthy specimens of Megaleporinus macrocephalus. The strains were selected from the intestinal tract of fish and inoculated in the Petri plate containing Sharp Man Rogosa Agar (MRS) for (48 hours at 35ºC). They were isolated based on a test of catalase, Gram stain, tolerance to different gradients NaCl (1, 2 and 3%), pH (4, 5, 6, 8 and 9) values and bile salts (2.5 and 5%), in addition to the inhibition zone against pathogens. Of the 42 strains isolated, ST1 and ST9 had higher values (p<0.05) for total viable cells (31.80±0.07 and 32.51±0.05 CFU/mL × 108) respectively. In the resistance tests, strains ST1 and ST9 presented the best results, with emphasis on ST9 in the gradients of pH, high values of bile salts and larger inhibition zones against Aeromonas hydrophila and Aeromonas jandaei. The strains with the best results in the tests, ST1 and ST9, were identified by the MALDI-TOF-MS method as Enterococcus faecium. Thus, the isolated E. faecium bacteria, may be recommended as for probiotic use in farming the M. macrocephalus.

Antibacterial Activity of Indian Spices against the Pathogens Isolated from Wound Infection

Introduction: Plants have been used for thousands of years to treat health disorders, to prevent diseases including epidemics, to flavor and conserve food. It is estimated that 250 to 500 thousand plant species are present on the earth, out of which merely 10 percent are used as a source of food by humans and animals. Objective: In the present work, antibacterial activity of five different Indian spices namely turmeric, clove, pepper, cinnamon and garlic was investigated against pathogens isolated from wound samples Method: The unknown bacteria were identified by different types of morphological and biochemical techniques such as serial dilutions spread plate methods, morphological studies and biochemical tests. The swabs of the patients were inoculated in 10 mL of sterile nutrient broth and incubated at 37oC for 24 h. The antibacterial activities of these Indian spices were evaluated using the disk diffusion method. A suspension of the microorganisms to be tested was spread on nutrient agar and MacConkey agar medium. The filter paper discs were placed on the agar plates, which were saturated with extract of spice. The plates were then incubated at 37oC for 24 h. The zone of inhibition was determined post-incubation by evaluating the diameter of the zone of inhibition. Results: The antibacterial activities of these Indian spices were evaluated using the disk diffusion method, and the inhibitory zones were recorded. It was quite evident from the result that cinnamon had a larger inhibition zone against P1NA3, P1MAC1 and least for P2NA2. Garlic exhibited a greater zone of inhibition against P2NA2, P3NA3 and least for P1MAC1. Clove had a maximum zone of inhibition against P1MAC2 and least with P3NA3. These spices displayed a zone of inhibition somewhat close to the control antibiotic drug, ampicillin. Conclusion: P1MNC2 showed a maximum zone of inhibition with clove (3 cm) at 100%. P2NA2 showed maximum antibacterial activity with garlic (3.6 cm) at 100% and minimum with cinnamon (1.1cm) at 20%. P3NA3 presented maximum antibacterial activity result with garlic (4.2 cm) at 100% and minimum with clove (1.2cm) at 20%. Spices are economical, more accessible to most of the population in the world. So, medicinal plants should be encouraged as potential candidates for new drugs.

Detection of Antifungal Activity of Cinnamon Extract on Candida Species Isolated from Diabetic Patients with Urinary Tract Infection Pre-COVID-19 Era

This study aimed to evaluate the antifungal activity of Cinnamon extract on Candida species isolated from 100 diabetic patients suffering from urinary tract infection between May to August 2018. Twenty-five Candida species were isolated, different Candida species were isolated then identified biochemically, in vitro sensitivity testing using well diffusion technique against Cinnamon extract was done. The cinnamon extract showed good antifungal activity against Candida species. The largest zone of inhibition against Candida tropicalis was (25 mm) and the least zone of inhibition was against Candida kefyr was (10 mm). The results of antimicrobial activity of crude extract were compared with the positive control (Clotrimazole) for evaluating their relative percentage inhibition and statistical significance the aqueous extract exhibited maximum relative percentage inhibition against Candida kefyr (89%) and minimum relative percentage inhibition against Candida glabrata was (12.3%). The p. values (0.018) are statistically significant.

Morphological and biochemical characterization of strains of Xanthomonas axonopodis pv. vignicola isolated from cowpea grown in three agroecological zones in Nigeria

Cowpea bacterial blight (Xanthomonas axonopodis pv vignicola) is a devastating disease of cowpea in Nigeria. Accurate identification is the first step for an effective management option. Thus, X. axonopodis pv. vignicola isolated from cowpea (Vigna unguinculata (L.) Walp) grown in different Agro-ecological zones in Nigeria were characterized using morphological characteristics, biochemical and antibiotic sensitivity tests. Pot experiments were conducted on two susceptible lines of cowpea (IT90k – 76) and (IT84s – 2246 – 4) in the screen house. In vivo infectivity studies were carried out to determine the effect of each of theX. axonopodis pv. vignicola isolate groups on the cowpea. All isolates from each of the agroecological zones were classified into Group 1 (light yellow) and Group 2 (brownish yellow) based on their morphological presentation on nutrient agar medium. Results from four of the biochemical test showed differences between the two morphologically different groups. Group 2 isolates showed a large zone of inhibition to a Lincomycin hydrochloride while isolates from Group 1 were not affected by the action of the same antibiotic. Blight symptom was only observed when the two types of isolates were combined and inoculated simultaneously. This study showed that there are two morpho-types of X. axonopodis pv. vignicola and their synergetic infectivity results in blight symptoms expression in cowpea.

Evaluation of Antibacterial Activity of Essential Oils of Melaleuca cajuputi Powell

Melaleuca cajuputi Powell is a tree species belonging to the family Myrtaceae and is widely used in traditional medicine. This study was conducted to investigate the antibacterial activities of essential oils of M. cajuputi Powell. Antibacterial activity was tested against Gram positive and Gram negative bacteria using the agar disc diffusion method. The essential oils of M. cajuputi were found to exert antibacterial activity against all of the tested bacteria, including Staphylococcus aureus, Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Escherichia coli. The zones of inhibition for S. aureus, S. pyogenes, MRSA, E. coli, and K. pneumoniae were 12.7 mm, 10.7 mm, 10.0 mm, 8.7 mm and 9.3 mm respectively, against 0.714% (w/w) of the essential oils. These results highlighted that Gram negative bacteria are less susceptible to the essential oils of M. cajuputi. A large zone of inhibition might be a sign of a leaching antimicrobial agent. These findings suggest that M. cajuputi is a potential natural antibacterial agent.

The Effectiveness of Mugwort Leaf Extract and Gotu Kola Leaf Extract against Acne Bacterial Activity

Acne is a problem among teenagers generally caused by bacterial infections such as Propionibacterium acnes, Staphylococcus aureus, and Staphylococcus epidermidis. Mugwort (Artemisia vulgaris L.) and Gotu Kola (Centella asiatica L.) extracts have antibacterial activity formulated in anti-acne gel preparations. The purpose of this study was to test and obtain a gel formula of mugwort leaf extract and gotu kola leaf extract which effectively kills and controls the growth of acne-causing bacteria. The methods used in this study include simplicity making, leaf extraction, making anti-acne gel preparations, testing pH, homogeneity, inhibition, and data analysis. The extract obtained by maceration was made in three concentrations, namely 2.50; 5.00; and 10.00%. The results showed that the pH value of the gel preparations obtained was in the range of 8.08-9.96. Mugwort leaf extract, gotu kola leaf, and mugwort-gotu kola have a distinctive smells with a thick texture at a concentration of 2.50% and a liquid texture at a concentration of 10.00%. Inhibition tests showed that the mugwort extract sample had a value of 16-18 mm, while the gotu kola extract and mugwort-gotu kola had a value of 14 mm. Mugwort leaf extract is able to inhibit the growth of acne-causing bacteria. This success was obtained because the extracts of mugwort and gotu kola leaves contain flavonoids that can inhibit the growth of bacteria that cause acne. Mugwort leaf extract gel with a concentration of 2.50 and 5.00% had the largest zone of inhibition in inhibiting P. acnes bacteria compared to other concentrations.

Antibacterial activity of bacteria isolated from earthworm (Pheretima sp.) gut against Salmonella typhi and Staphylococcus aureus: in vitro experiments supported by computational docking

Abstract. Husain DR, Wardhani R, Erviani AE. 2022. Antibacterial activity of bacteria isolated from earthworm (Pheretimasp.) gut against Salmonella typhiand Staphylococcus aureus: in vitro experiments supported by computational docking. Biodiversitas 23: 1125-1131. Bacteria have a diverse ecology niche as the effect of a long evolutionary process. They can live along with other organisms as endosymbiont. Research into endosymbiont bacteria began because of their ability to increase host resistance, especially to pathogens. This study aimed to determine the antimicrobial ability of endosymbiont bacterial isolates of earthworms Pheretimasp., Bacillus brevis, and Bacillus choshinensis that inhabit Pheretimasp. were isolated.The isolates were grown on tryptic soy broth media for 24 hours. The isolates were then purified using tryptic soy agar and biochemically tested to ensure both isolates are endosymbiotic bacteria. Antimicrobial activity was tested using agar diffusion methods in pathogenic bacteria, Staphylococcus aureus, and Salmonella typhi. Amoxicillin and chloramphenicol were used as positive controls. The inhibitory test results showed that incubation for 15 days effectively assessed pathogenic bacteria growth inhibition, marked by the largest inhibition zone (21.32 mm for Salmonella typhi and 16.88 mm for Staphylococcus aureus). They were very effective at inhibiting Salmonella typhiand Staphylococcus aureus growths.Endosymbiotic compounds’ had a potential as antimicrobial. The in silico test supports the inhibitory test, which concluded that endosymbiont isolates can be an antimicrobial characterized by low-binding affinity values (-8,6 on tyrocidine) on molecular docking analysis.

Formulation of an antibacterial topical cream containing bioengineered honey that generates reactive oxygen species

SurgihoneyRO™ (SHRO) is a bioengineered medicinal honey proven to eradicate multi-drug resistant strains of bacteria by delivering a controlled dose of reactive oxygen species (ROS). The urgent need for novel antimicrobial therapies capable of tackling pathogens that have developed resitance to existing antimicrobial medicines, such as antibiotics, makes SHRO a highly desirable biomaterial. However, its application is currently limited in the medical field due to undesirable material properties. This study aims to formulate the honey into a clinically viable topical cream whilst maintaining antimicrobial efficacy. SHRO droplets were emulsified to protect the active until activation in-situ. Xanthan gum (XG) and fumed silica (FS) thickener systems were explored, with both formulations able to inhibit the growth of S. aureus in-vitro. However, FS formulations exhibited significantly higher hydrogen peroxide release over a period of 7 days and resulted in larger zones of inhibition (42%) than XG formulations. Selection of the optimum FS formulation was made based on evaluation of the material characteristics by means of rheology and texture analysis. In place of the sticky and highly viscous initial SHRO product, desirable material characteristics for a topical product were achieved, including thixotropic shear-thinning behaviour and significantly lower cohesiveness (15.3–22.4 N) than standard SHRO formulations (79.9 N). Furthermore, the product exhibited a low contact angle on porcine skin, indicating that these formulations would spread favourably on the skin surface, demonstrate a favourable sensory perception and be retained on the skin, making for a more clinically effective product. This work is the first report of an engineered cream system to controllably deliver ROS to a wound site and demonstrate its ability of eradicating clinically relevant bacteria in vitro.

In Vitro Antibacterial Activity of Marine Microalgae Extract against Vibrio harveyi

Marine microalgae may produce antibacterial substances. At the exponential phase of growth, four species of marine microalgae were examined for their potential to create secondary metabolites that limit the growth of Vibrio harveyi: Nannochloropsis oceanica, Chaetoceros gracilis, Isochrysis sp., and Thalassiosira weissflogii. V. harveyi is a pathogenic bacteria that can cause severe mortality and loss in aquaculture. Disc diffusion assay and co-culture assay were used to determine antibacterial activity. On TSA % NaCl media, the disc impregnated with microalgae and extracted with ethanol, methanol, saline water, and dimethyl sulfoxide (DMSO) was tested against V. harveyi at concentrations of 1.0 × 105, 106 and 107 CFU mL−1. The disc diffusion assay revealed that N. oceanica extracted with ethanol had the largest inhibitory zone against V. harveyi. Meanwhile, only N. oceanica, Isochrysis sp., and T. weissflogii reduced the growth of V. harveyi (105 CFU mL−1) in the co-culture assay (p < 0.05). The current findings reveal that the hydrophilic chemicals in microalgae extract have antibiotic activity against the highly virulent V. harveyi, which causes vibriosis, a serious disease in farmed fish and aquaculture cultivation around the world.

Potential of Antibacterial Activity in Natural Ingredients (Betel Leaves, Basil Leaves, Avocado Seeds, Lemongrass, Garlic) As Natural Hand Sanitizers: Journal Review

In an effort to reduce the use of alcohol-based hand sanitizers because of their quite dangerous impact on the skin, natural hand sanitizers are an alternative. The antibacterial substances in betel leaves, basil leaves, avocado seeds, lemongrass, and garlic can be used as materials for natural hand sanitizers. The purpose of this study was to collect, identify, and compare journals about the effectiveness of antibacterial agents in natural ingredients that are used as natural hand sanitizers. Using the journal review method through reviewing the contents of journals that discuss antibacterial activity, the results show that the five phytochemical compounds contain active antibacterial compounds so that they have the potential to make natural hand sanitizers, as well as the antibacterial inhibition zone of these five ingredients showing high results with strong to very strong categories. It was concluded that the five ingredients could be used as natural hand sanitizer materials. However, betel leaves are preferred because of their largest inhibition zone, 3.1-4.0 cm.

EFFECT OF ESSENTIAL OIL EXTRACTED FROM AZADIRACHTA INDICA (NEEM) LEAVES IN FORMULATED NATURAL ANTIBACTERIAL SOAP

Natural remedy is sustainable in nature and was used in this present study, effects of essential oils from Azadirachta indica (neem) leaves in antibacterial soap was investigated. The essential oil was extracted via steam distillation and characterization of oil results are %yield (28%), acid value (16.5±0.5mg KOH/g); iodine value (42.40±2.5mgI/g)and saponification values (139±3.2mg KOH/g). The extract proportions 2, 4, 6, 8 and 10 (mg/ml) respectively were used to formulate the soaps. The results of the soap characterization were: pH (9.3); foamability (3.5cm), color (light yellow).The antibacterial investigation used Ciprofloxacin and ketoconazole as positive controls whereas Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans were clinical isolates of microbes used. Sensitivity test was conducted and an in vitro evaluation of the anti-microbial activity was conducted using ditch-plate techniques. Strains of reference microbes namely Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli were tested at four different soaps’ concentrations (0.0, 2.0, 5.0 and 8.0 mg/ml). ANOVA mean results of zones of inhibition also revealed variability of antimicrobial activity among the natural formulated soaps with strong positive correlation (r= 0.9912 ; P > 0.01) between zones of inhibition and soaps’ concentrations was evidenced. Blend 8:2 of the formulation exhibited the largest zone of inhibition (40 mm) on S. aureus, followed by Candida albicans with (35 mm) zone of inhibition whereas the least zone of inhibition (1.8 mm) was observed in 2mg/ml extract formulation. The high pH shows it conforms to NAFDEC set range of 9 to 11 pH. Therefore with local oil, National Economic Transformation is achieved hence, this highly sustainable product is recommended to homes, pharmaceutical companies, health organizations and government in handling topical issues related to skin infections caused by micro organisms.

Are alkaline spices the future of antibiotics?

Some developing countries do not have access to the same medicine and antibiotics that developed countries do. Thus, we chose to focus on compounds and spices that have antimicrobial properties with a history of being used in traditional medicine but are not commonly used in developed countries. We experimented with the most commonly available alkaline spices (turmeric, cayenne pepper, and cinnamon) to study their antimicrobial properties. Our hypothesis was that alkaline spices would have antimicrobial activity. We used oral swabs from three volunteer subjects to inoculated blood-agar plates. The result of our 24-hour (bacteriostatic) experiment showed a zone of inhibition of bacterial growth, with the largest zone of inhibition being around turmeric, followed by cayenne pepper, and the smallest around cinnamon. The 48-hour (bactericidal) results were similar, but with added complexity in turmeric and cayenne pepper showing a mold-like substance with a zone of bacterial inhibition not seen with cinnamon. These results are impactful and support our hypothesis, as alkaline spices generally do show antibacterial properties and both bacteriostatic and bactericidal effects correlated with degree of alkalinity. Further studies with an increased number of spices and with a larger sample size are needed to validate our findings.

Biogenic Synthesis, Characterization and Antibacterial Properties of Silver Nanoparticles against Human Pathogens.

Biogenic synthesis of silver nanoparticles (AgNPs) is more eco-friendly and cost-effective approach as compared to the conventional chemical synthesis. Biologically synthesized AgNPs have been proved as therapeutically effective and valuable compounds. In this study, the four bacterial strains Escherichia coli (MT448673), Pseudomonas aeruginosa (MN900691), Bacillus subtilis (MN900684) and Bacillus licheniformis (MN900686) were used for the biogenic synthesis of AgNPs. Agar well diffusion assay revealed to determine the antibacterial activity of all biogenically synthesized AGNPs showed that P. aeruginosa AgNPs possessed significantly high (p < 0.05) antibacterial potential against all tested isolates. The one-way ANOVA test showed that that P. aeruginosa AgNPs showed significantly (p < 0.05) larger zones of inhibition (ZOI: 19 to 22 mm) compared to the positive control (rifampicin: 50 µg/mL) while no ZOI was observed against negative control (Dimethyl sulfoxide: DMSO). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) concentration against four test strains also showed that among all biogenically synthesized NPs, P. aeruginosa AgNPs showed effective MIC (3.3-3.6 µg/mL) and MBC (4.3-4.6 µg/mL). Hence, P. aeruginosa AGNPs were characterized using visual UV vis-spectroscopy, X-ray diffractometer (XRD), fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The formation of peak around 430 nm indicated the formation of AgNPs while the FTIR confirmed the involvement of biological molecules in the formation of nanoparticles (NPs). SEM revealed that the NPs were of approximately 40 nm. Overall, this study suggested that the biogenically synthesized nanoparticles could be utilized as effective antimicrobial agents for effective disease control.

Antimicrobial evaluation of Bovine Lactoferrin: A bioactive protein isolated from milk of crossbred and Indigenous cow breeds

A multifunctional iron-binding glycoprotein called lactoferrin (Lf) acts as a broad-spectrum first line of defense against fungi, protozoa, bacteria, and viruses. Bovine Lactoferrin (BLf), which was extracted from the milk of crossbred and native breeds of cattle, was investigated for its antibacterial properties. The BLf protein was purified from the milk of HF crossbred and indigenous breeds like Sahiwal and Poda thurpu cows using the cation-exchange chromatography method and Broth microdilution and disc diffusion techniques were used to investigate the antibacterial activity. The minimum inhibitory concentration (MIC) of isolated BLf from the milk of HF cross-bred cow was found at 8000 μg/mL against Staphylococcus aureus and BLf isolated from the milk of Sahiwal and Poda thurpu cattle breeds respectively showed MIC of 4000 μg/mL against S. aureus. The MIC against Bacillus spp. was at 4000 μg/mL for all the experimental cow breeds. The MIC value of isolated BLf from Holstein-Friesian (HF) cross bred against Escherichia coli and Proteus spp. was 4000 μg/mL. However, the MIC for isolated BLf) from Sahiwal and Poda thurpu breeds against E. coli and Proteus spp. in the present study was 2000 μg/mL. The antimicrobial activity was also studied by disc diffusion studies against selected gram-positive and gram-negative bacteria. The BLf isolated from the milk of all the three experimental breeds showed a smaller zone of inhibition at 2000 μg/mL concentration and a larger inhibition zone was observed at 4000μg/mL against the selected gram-positive and gram-negative bacteria. However, more potency was shown by the BLf isolated from the indigenous breed viz. Poda thurpu followed by Sahiwal.

Isolation, Identification and Screening of Bacillus species with Antimicrobial Activity from Different Soil Samples of Kathmandu Valley

Bacillus species are one of the predominant soil bacteria that are able to produce essential secondary metabolites that have antagonistic effects on other microorganisms. They are Gram-positive, endospore-forming, chemoheterotrophic, aerobic or facultative anaerobic rods usually consisting of peritrichous flagella for motility. The major aim of this study was to isolate the antimicrobials producing Bacillus spp. from soil samples of different parts of the Kathmandu Valley, identify them and to assess their antimicrobial activity against different pathogenic bacteria. The test organisms used were Staphylococcus aureus (ATCC 25923), E. coli (ATCC 25922), Pseudomonas spp., Salmonella spp., methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase (ESBL) producing E. coli. Twenty four isolates from 9 soil samples identified as Bacillus spp. showed the zone of inhibition around their growth on Nutrient agar during isolation. These 24 isolates were chosen for primary screening of production of antimicrobial by perpendicular streaking method using four test organisms. . Of these 24 isolates, six isolates showing a significant zone of inhibition (≥1mm) against two or more test organisms from the primary screening were chosen for secondary screening which was further tested with six test organisms including ESBL E.coli and MRSA. They were further characterized through different physiological and biochemical tests. All 6 isolates showed inhibitory action against MRSA and the largest zone of inhibition (30mm) was shown by isolate U6. Isolate U3 was found to have broad spectrum antimicrobial activity with inhibitory effect against gram negative organisms- Pseudomonas and Salmonella and gram positive organism S. aureus (ATCC 25923). Isolate U5 showed a zone of inhibition of about 25mm against S. aureus which was comparable to that of erythromycin. Hence, this study determines the soil in Kathmandu Valley as a potential source of antimicrobial producing Bacillus spp. and recommends isolation and further characterization of Bacillus isolates as a possible source of novel drug to combat with the emergence of multidrug resistant strains.

Fungicidal effects of homoeopathic medicines versus allopathic ketoconazole in Candida albicans

Background: Candida albicans, accounts for more than 75% of all Candidal infections. Apart from its growing prevalence, it is also one of the most resistant strains against antifungal medication. Homoeopathy is an alternative to allopathic medication and has shown inhibiting fungal growth. Objective: This study was to determine effectiveness of homoeopathic tinctures and medications versus allopathic Ketoconazole in growth inhibition and fungicidal properties against in vitro cultures of C. albicans. Materials and Methods: Efficacy of five antifungal agents were tested for inhibiting fungal growth and their fungicidal properties on cultured C. albicans the agents tested were Eucalyptus globulus and Ocimum basilicum in essential oil form, Benzoicum Acidum 30C and Kali Iodatum 30C in tablet form, and compared with the effect of 100 mg Ketoconazole in powder form. Results: In the growth inhibition trial, O. basilicum had the largest zone of inhibition followed by E. globulus following. The ketoconazole group showed similar inhibition rates with Benzoicum Acidum 30C, and Kali Iodatum 30C showed more inhibition than Ketoconazole. The present data suggests that no individual agent had an effective fungicidal effect on C. albicans, only causing a minimal reduction on the surface in the fungal colony. Conclusion: Results indicate that essential oils O. basilicum and E. globulus were most effective in growth inhibition. However, both essential oil and homoeopathic treatment had limited fungicidal properties. This concludes that homoeopathic alternatives can be effective in preventing fungal infections but may be less effective in treatment of a fully developed C. albicans infection.

Synthesis of arylidene‐based benzoxazine derivatives as promising antimicrobial materials

AbstractThe current study is focused on the synthesis of two novel arylidene‐based benzoxazines namely: 3‐(3‐phenyl‐3,4‐dihydro‐2H‐benzo[e][1,3]oxazin‐6‐yl)‐1‐(thiophen‐2‐yl)‐2‐propenone (PTP), and 3‐(3‐phenyl‐3,4‐dihydro‐2H‐benzo[e][1,3]‐oxazin‐6‐yl)‐1‐(pyridin‐2‐yl)‐2‐propenone (PPP). The benzoxazines were obtained as condensation products of the reaction of each of the phenol analogs: [3‐(4‐hydroxyphenyl)‐1‐(2‐thiophenyl)‐2‐propenone] (HTP), and [3‐(4‐hydroxyphenyl)‐1‐(2‐pyridinyl)‐2‐propenone] (HPP), with aniline, and paraformaldehyde, respectively. PTP and PPP were structurally confirmed using analysis such as ultraviolet (UV) spectroscopy, together with FTIR, and 1H‐NMR and 13C‐NMR spectral analyses, respectively. The benzoxazine derivatives revealed an excellent antimicrobial activity against the selected bacterial (including Gram‐positive &amp; Gram‐negative) and fungi. The antimicrobial activity was also investigated using the agar diffusion approach. The qualitative assay of the biological study from the inhibition zones for the PTP, PPP, and PBO revealed interesting results. The examinations revealed some levels of antimicrobial efficacy against the selected bacterial strains used. However, the biological efficacy of PTP appeared to be better with larger zones of inhibition against the growth of the micro‐organisms. Moreover, the molecular docking studies of PTP, PPP, and PBO derivatives were screened against the “5FSA” protein. PPP derivative displayed a good activity than the other derivatives PTP and PBO in docking with 5FSA protein. The obtained values were −7.34, −7.70, and −5.70 Kcal/Mol for PPP, PTP, and PBO respectively compared to Fluconazole reference value −7.86 Kcal/Mol.

Preparation of highly efficient chitosan-based flame retardant coatings with good antibacterial properties for cotton fabrics

Improving the flame retardancy, thermal stability and antibacterial properties of cotton fabric are necessary for using it safely. To achieve this goal, melamine phosphate (MP) was added to nanochitosan (nCH) and polyvinyl alcohol (PVA) solution to prepare flame retardant coatings for cotton fabric. In addition, melamine salt of chitosan phosphate (MCHP) was prepared, mixed with PVA and used as a coating for cotton fabric. Limiting oxygen index (LOI) data indicated that PVA/nCH/MP and PVA/MCHP coatings increased LOI of cotton fabric from 17.2% to 57.9% and 58.2%, respectively. Horizontal burning rate and vertical flame spread measurements manifested, that the flame did not propagate in all treated samples. SEM images of char residue after the vertical flame spread test showed the formation of an intumescent char layer on the fabric surface that protected cotton fabric from heat and flame. The antibacterial properties against both pathogenic gram-positive (S. aureus) and gram-negative (E-coli) bacteria presented that treated samples demonstrate large inhibition zone diameters (IZD) relative to the control sample. Furthermore, the flame retardant coatings enhanced the control sample thermal stability and char residue at high temperatures. The tensile strength, water wettability, air permeability and stiffness of treated samples were measured. Durability study exhibited that treated samples were able to preserve high flame retardancy properties after the washing process.