Effect of novel therapeutic medicine swertiamarin from Enicostema axillare in zebrafish infected with Salmonella typhi.

Herbal treatments have been practiced by humans over centuries and therefore possess time-proven safety. However, it is crucial to evaluate the toxic effects of herbal medicine to confirm their safety, particularly when developing therapeutic drugs. Use of laboratory animals such as mice, rat, and rabbits was considered as gold standard in herbal toxicity assessments. However, in the last few decades, the ethical consideration of using higher vertebrates for toxicity testing has become more controversial. As a possible alternative model involving lower vertebrates such as zebra fish were introduced. Hence in the present study, swertiamain compound isolated from E. axillare was assessed for it antimicrobial activity in zebra fish larvae againt S. typhi. The cumulative mortality rate and bacterial localization in zebra fish larvae were studied. Biochemical markers assays were performed to find the preventive role of the compound during the typhoid infection. The results showed that zebra fish can be successfully used as a model to study typhoid infection and the anti-bacterial compound swertiamarin used in this study clears the bacterial load and pathogenic symptoms to a great extent.

Assessment of free radicals and reactive oxygen species milieu in nanoparticles adjuvanted outer membrane proteins vaccine against Salmonella typhi.

In this study, calcium phosphate nanoparticles-based (STCNV) and montanide oil adjuvant vaccine (STOAV) containing outer membrane proteins (Omps) of S. Typhi were evaluated for inducing oxidative stress indicators [reduced glutathione (GSH), lipid peroxidation (LPO), catalase, superoxide dismutase (SOD), and total protein] in the tissues of mice after vaccination. The GSH levels though slightly high in the liver, kidney, and lungs of STCNV group were not significantly different from STOAV and the control group (STC). There was no significant difference in LPO levels in any group for any tissue. The significantly lower activities of catalase were observed in the kidney and lungs of the STCNV group as compared to STOAV and STC group, while in the liver, STCNV group revealed lower catalase activity in comparison to the control group. No significant difference in the SOD activities between the two vaccinated groups was observed. The total protein contents in all the organs showed no significant difference in the vaccinated and the control group. The vaccines may induce long-term inflammatory response and consequently damage vital organs; this study revealed no long-term oxidative stress in all the three vital organs, suggesting that these vaccines may not cause oxidative damages in the vital organs of mice.

Ceftriaxone treatment failure in two cases of Enteric Fever caused by CTX-M15 positive Salmonella Typhi and its gastrointestinal carriage.

We report two cases of culture positive typhoid fever caused by ceftriaxone resistant Salmonella Typhi. Bacterial isolates from both the cases were positive for ESBL by phenotypic methods. Both patients didn't respond to ceftriaxone and were finally treated with meropenem. Screening of family members of one patient isolated a similar strain from a healthy carrier with the same antibiogram pattern. All isolates were subjected to PCR, which confirmed the presence of blaCTX-M15 ESBL gene. These two cases confirm emergence of ESBL-producing Salmonella Typhi causing Enteric Fever in India and also their presence in the gut flora of healthy carriers.

Calcium phosphate adjuvanted nanoparticles of outer membrane proteins of Salmonella Typhi as a candidate for vaccine development against Typhoid fever.

Introduction. The conventional adjuvants used in vaccines have limitations like induction of an imbalanced Th1 and Th2 immune response. To overcome this limitation, novel adjuvants and newer forms of existing adjuvants like calcium phosphate nanoparticles are being tested.Hypothesis/Gap Statement. Calcium phosphate adjuvanted outer membrane proteins vaccine may work as an efficient, safe and cost effective vaccine against Salmonella Typhi.Aim. Our goals were to evaluate the potential of calcium phosphate nanoparticles as an adjuvant using outer membrane proteins (Omps) of Salmonella Typhi as antigens for immune response, with montanide (commercially available adjuvant) as control, and its toxicity in rats.Methodology. Calcium phosphate adjuvanted outer membrane proteins nanoparticles were synthesized and characterized. The efficacy of vaccine formulation in mice and toxicity assay were carried out in rats.Results. The calcium phosphate nanoparticles varying in size between 20-50 nm had entrapment efficiency of 41.5% and loading capacity of 54%. The calcium phosphate nanoparticle-Omps vaccine formulation (nanoparticle-Omps) induced a strong humoral immune response, which was significantly higher than the control group for the entire period of study. In the montanide-Omps group the initial very high immune response declined steeply and then remained steady. The immune response induced by nanoparticle-Omps did not change appreciably. The cell mediated immune response as measured by lymphocyte proliferation assay and delayed type hypersensitivity test showed a higher response (P<0.01) for the nanoparticles-Omps group as compared to montanide-Omps group. The bacterial clearance assay also showed higher clearance in the nanoparticles-Omps group as compared to montanide-Omps group (approx 1.4%). The toxicity analysis in rats showed no difference in the values of toxicity biomarkers and blood chemistry parameters, revealing vaccine formulation was non-toxic in rats.Conclusion. Calcium phosphate nanoparticles as adjuvant in vaccines is safe, have good encapsulation and loading capacity and induce a strong cell mediated, humoral and protective immune response.

In Vitro Antibacterial Activity of Different Honey Samples against Clinical Isolates.

BACKGROUND: The emergence of multi-drug-resistant organisms has created a lot of clinical problems. Hence, there is a need to find natural alternative treatment to counter the multi-drug-resistant organisms. Honey has a well-established usage as wound dressing in ancient and traditional medicine. OBJECTIVE: The objective of this study is to establish a baseline for the antibacterial activity of 32 global raw natural and commercial various honey samples against 8 clinical isolates. METHODS: Thirty-two honey samples (raw and commercial honey) collected from different global countries with different floral origins were tested in vitro for antibacterial activity against 8 clinical isolates collected from patients, at private hospital from Sudan, using disk diffusion technique. The following 6 epsilometer tests (Etest), amoxicillin, ciprofloxacin, cefotaxime, chloramphenicol, gentamicin, and tetracycline, were used against 8 clinical isolates for Minimum Inhibitory Concentration (MIC). RESULTS: The following 8 clinical isolates were identified by conventional bacteriological methods: Staphylococcus aureus, (S. aureus) Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), Pseudomonas aeruginosa (P. aeruginosa), Proteus vulgaris (P. vulgaris), Salmonella Typhi (S. Typhi), Shigella sonnei (S. sonnei), and methicillin-resistant Staphylococcus aureus (MRSA). Both raw natural and commercial honey exhibited antibacterial properties against tested Gram-positive and Gram-negative bacteria. The tested organisms showed low sensitivity to antibiotic Etest. CONCLUSION: All of the bacterial species studied were uniformly receptive to all raw and commercial tested honey samples; in contrast, the tested organisms showed low sensitivity to antibiotics. Commercial honey has the same antibacterial activity as the raw natural unprocessed honey against tested clinical isolates. Thus, honey is a successful alternative to conventional antibiotics as has been proved against clinical isolates.

In-Vitro Evaluation of Antimicrobial Activities of Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Neisseria gonorrhoeae, and Candida albicans Nosodes.

BACKGROUND: This study presents the results of the minimum inhibitory concentration (MIC) assay of a series of nosodes: namely Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Neisseria gonorrhoeae, and Candida albicans. Each was tested against its corresponding infection as well as cross infections. METHODS: In-vitro efficacy of polyvalent nosodes was tested using the MIC assay technique. The nosodes, namely C. albicans polyvalent nosode (35c, 100c), N. gonorrhoeae (35c), K. pneumoniae (35c, 100c), E. coli polyvalent nosode (35c, 100c) and Salmonella typhi polyvalent nosode (30c, 100c), were tested along with positive and negative controls. Nosodes were studied in different potencies and at 1:1 dilution. RESULTS: C. albicans polyvalent nosode 35c, 100c, N. gonorrhoeae 35c, and positive control amphotericin B showed inhibition of the growth of C. albicans species. K. pneumoniae 35c, E. coli polyvalent nosode 100c, and meropenem (positive control) showed inhibition of the growth of K. pneumoniae; this effect was not seen with ceftriaxone, ofloxacin and amoxicillin antibiotics. E. coli polyvalent nosode 30c in 10% alcohol (direct and dilution 1:1) and the positive controls ciprofloxacin, ofloxacin, and amoxicillin showed inhibition of the growth of E. coli. The S. typhi polyvalent nosode 30c in 10% alcohol showed inhibition of growth of S. typhi. CONCLUSION: This study reveals that the tested nosodes exhibited antibacterial potential against the corresponding micro-organisms and against other selected organisms studied using this assay.

An in vitro investigation of the phytochemical contents of Marsdenia macrantha root and its antibacterial activity against selected foodborne pathogens.

INTRODUCTION: Marsdenia macrantha is a crucial source of traditional medicine in Northern Namibia. Its roots are used to treat various health conditions ranging from mouth infections to urinary retention. Despite its medicinal application, there is no known knowledge of its therapeutic properties. Thus, we investigated the phytochemical content and antibacterial activity of M. macrantha. METHODS: M. macrantha root extracts were obtained using three different solvents (distilled water, methanol and acetone) - in the soxhlet and maceration extraction methods. Total phytochemical (terpenoid, alkaloid and/or flavonoid) content was determined by spectrophotometry. Antibacterial activity against common foodborne pathogens (Staphylococcus aureus, Escherichia coli and Salmonella typhi) was determined by both well and disc diffusion method. RESULTS: we detected the presence of all the tested phytochemicals. Methanol gave the highest percentage yield of extraction (mean: 13.95 ± standard deviation: 0.41%) followed by water (10.92 ± 0.11%) and acetone (6.85 ± 0.23%), F-ratio=326.71 and p<0.0003. The total content determined showed that M. macrantha root extract contained more flavonoids than alkaloids (mg of standard per grams of the dry material). Antibacterial analyses showed inhibitory activity against all the selected pathogens, with the highest inhibition zone against S. typhi (19.7 ± 0.3 mm) - for the acetone-prepared root extract. There were variations in minimum inhibitory concentrations of the extracts prepared by the different solvents. CONCLUSION: this is the first study demonstrating the presence of phytochemicals and antibacterial properties of M. macrantha roots. Further studies are needed to isolate and characterize the phytochemicals for antibacterial application.

Development, characterization and evaluation of in vitro anti-inflammatory activity of Withania coagulans extract and extract loaded microemulsion.

Herbal medicines are gaining importance due to more advantages and less toxic effects. Withania coagulans is natural plant that possesses multiple activities. Its main constituents are withaferin and withanolide. The purpose of present study is to identify main constituent of Withania coagulans and preparation of extract loaded micro emulsions. Withania coagulans fruit extract in methanol/chloroform (1:1) was collected in semisolid form and LCMS was done to identify active compound, and then micro emulsions were prepared using Tween 80: Transcutol (1:1) Frankincense oil, and water to enhance its stability for topical application. Five formulations were prepared by Pseudo ternary phase diagram and evaluated for pH, conductivity, viscosity, drug contents, particle size analysis, and polydispersity. Withania coagulans extract was evaluated for anti-bacterial activity against (Staphylococcus aureus, E. coli, and S. typhi) and anti-fungal activity against (Candida albicans and Aspergillus niger). Anti-inflammatory activity was checked for both extract and Extract based micro emulsion. Among all five formulations F5 shows best physiochemical properties with small globule size, good stability and high anti-inflammatory activity. Based on these results it was concluded that Withania coagulans extract loaded micro emulsions can be used for topical application with promising anti-inflammatory activities. Data for in-vivo studies for checking the topical effect of Withania coagulans is provided elsewhere.

Antimicrobial and antioxidant activity of catechin-3-o-rhamnoside isolated from the stem bark of Lannea kerstingii Engl. and K. Krause (Anacardiaceae).

Various epidemiological researches have shown that consumption of vegetables and fruits are essential to maintain health and prevent diseases but the emergence of more and more drug resistance bacteria has led to high mortality. Thus the study of the antimicrobial and antioxidant activities of a flavonoid (Catechin-3-o-rhamnoside) isolated for the first time from Lannea kerstingii. Catechin-3-o-rhamnoside was isolated using dry vacuum liquid chromatography. It was characterized using 1H-NMR, 13C-NMR and 2D NMR spectra. The antimicrobial activity was determined using agar diffusion and broth dilution method. Antioxidant activity was determined through reaction of the compound with DPPH radical. The compound was active against, Methicillin Resistant Staphylococcus aureus, S. aureus, B. subtilis, E. coli, K. pneumoniae, S. typhi, S. dysentariae, C. albicans and C. tropicalis with zone of inhibition ranging from 22.0±0.1 to 35.0±0.2mm and inactive against vancomycin resistant enterococci, Proteus mirabilis and C. ulcerans. The MIC ranged from 6.25 to 12.5µg/ml while the MBC/MFC ranged from 12.5 to 50.0µg/ml. The compound showed a high radical scavenging activity with EC50 of 46.87µg/ml. These results show a potential lead drug for resistant bacteria and natural antioxidants.

Open Label Randomized Controlled Comparison of Three Alternative Regimes of Ciprofloxacin, Azithromycin and Cefixime for Treatment of Uncomplicated Typhoid Fever in Bangladesh.

Multi-drug resistant Typhoid fever (resistant to previously used chloramphenicol, ampicillin, amoxicillin, and trimethoprim-sulfamethoxazole) has been commonly described in the South East Asia region and a recent report suggests that the salmonella typhi have reduced response to fluoroquinolones (nalidixic acid-resistant). The optimum treatment protocol for this type of serovar has not been established. This study compared different antimicrobial regimens for the treatment of uncomplicated typhoid fever which was conducted in the medicine ward of Dhaka Medical College Hospital (DMCH) and outdoor setting in private practice in Dhaka metropolitan city, Mymensingh and Sylhet town from January 2017 to December 2017. Bangladeshi adults with uncomplicated typhoid fever were included in this an open-label randomized controlled trial. Ciprofloxacin (20mg/kg of body weight/day for 14 days), azithromycin (20mg/kg/day for 14 days), and Cefixime (16mg/kg/day for 14 days) were compared. Of the 81 enrolled patients, 62 were eligible for analysis (61 S. enterica serovar Typhi, 1 Salmonella enterica serovar paratyphi A). Of the S enterica serovar Typhi isolates, 88.7% (55/62) were MDR and 93.5% (58/62) were nalidixic acid resistant (NAR). The clinical cure rate was 62% (13/21) with ciprofloxacin, 71% (15/21) with Cefixime, and 85% (17/20) with azithromycin (p=0.053). The mean (95% confidence interval [CI]) fever clearance time for patients treated with azithromycin (5.8 days [5.1 to 6.5 days]) was shorter than that for patients treated with cefixime (7.1 days [6.2 to 8.1 days]) and ciprofloxacin (8.2 days [7.2 to 9.2 days]) (p<0.001). All three antibiotics were well tolerated. A 7-day course of azithromycin can be successfully used in uncomplicated typhoid fever due to isolates of MDR S enterica serovar Typhi.

Preparation and Standardization of Nosodes Sourced from Klebsiella Pneumoniae, Salmonella Typhi, Neisseria Gonorrhoeae and Candida Albicans Strains.

BACKGROUND: Homeopathic nosodes prepared from organisms and pathological tissues have shown biological effects, encouraging more research. There is a need to develop some new nosodes systematically and to re-make others that were developed over a century ago. In our program of work on nosodes, the bacterial strains Klebsiella pneumoniae (BAA 2146), Salmonella typhi and Neisseria gonorrhoeae (ATCC 43069), and the single-celled fungus Candida albicans (24433, 26790, and 60193) have been identified for preparation. MATERIALS AND METHODS: The systematic and scientific method of preparation of nosodes includes identification, culture, quantification, characterization, preparation, and standardization. Under laminar flow, a suspension of respective bacterial and fungal cells (20 billion cells/mL) was processed as per the Homoeopathic Pharmacopoeia of India (HPI). Culture tests, sterility tests and molecular testing (polymerase chain reaction) were performed to establish the absence of contamination, live organisms and DNA material. RESULTS: K. pneumoniae, S. typhi (single, bivalent, or polyvalent), N. gonorrhoeae, and C. albicans nosodes (single and polyvalent) were sourced and prepared from different strains of respective cultures. The nosode preparations were processed by serial dilution and potentization, normally following the HPI guidelines. Molecular test results showed the absence of live organisms or DNA material; culture and sterility test results demonstrated the safety profile of the potentized nosodes. CONCLUSION: K. pneumoniae, S. typhi, N. gonorrhoeae and C. albicans nosodes were successfully prepared. Their therapeutic potential may now be evaluated.

Regulation of Th1 T Cell Differentiation by Iron via Upregulation of T Cell Immunoglobulin and Mucin Containing Protein-3 (TIM-3).

Iron plays an important role in host-pathogen interactions, in being an essential element for both pathogen and host metabolism, but also by impacting immune cell differentiation and anti-microbial effector pathways. Iron has been implicated to affect the differentiation of T lymphocytes during inflammation, however, so far the underlying mechanism remained elusive. In order to study the role of iron in T cell differentiation we here investigated how dietary iron supplementation affects T cell function and outcome in a model of chronic infection with the intracellular bacterium Salmonella enterica serovar typhimurium (S. Typhimurium). Iron loading prior to infection fostered bacterial burden and, unexpectedly, reduced differentiation of CD4+ T helper cells type 1 (Th1) and expression of interferon-gamma (IFNγ), a key cytokine to control infections with intracellular pathogens. This effect could be traced back to iron-mediated induction of the negative immune checkpoint regulator T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), expressed on the surface of this T cell subset. In vitro experiments demonstrated that iron supplementation specifically upregulated mRNA and protein expression of TIM-3 in naïve Th cells in a dose-depdendent manner and hindered priming of those T cells towards Th1 differentiation. Importantly, administration of TIM-3 blocking antibodies to iron-loaded mice infected with S. Typhimurium virtually restored Th1 cell differentiation and significantly improved bacterial control. Our data uncover a novel mechanism by which iron modulates CD4+ cell differentiation and functionality and hence impacts infection control with intracellular pathogens. Specifically, iron inhibits the differentiation of naive CD4+ T cells to protective IFNγ producing Th1 lymphocytes via stimulation of TIM-3 expression. Finally, TIM-3 may serve as a novel drug target for the treatment of chronic infections with intracellular pathogens, specifically in iron loading diseases.

Isolation, Structure Elucidation and In Silico Prediction of Potential Drug-Like Flavonoids from Onosma chitralicum Targeted towards Functionally Important Proteins of Drug-Resistant Bad Bugs.

Admittedly, the disastrous emergence of drug resistance in prokaryotic and eukaryotic human pathogens has created an urgent need to develop novel chemotherapeutic agents. Onosma chitralicum is a source of traditional medicine with cooling, laxative, and anthelmintic effects. The objective of the current research was to analyze the biological potential of Onosma chitralicum, and to isolate and characterize the chemical constituents of the plant. The crude extracts of the plant prepared with different solvents, such as aqueous, hexane, chloroform, ethyl acetate, and butanol, were subjected to antimicrobial activities. Results corroborate that crude (methanol), EtoAc, and n-C6H14 fractions were more active against bacterial strains. Among these fractions, the EtoAc fraction was found more potent. The EtoAc fraction was the most active against the selected microbes, which was subjected to successive column chromatography, and the resultant compounds 1 to 7 were isolated. Different techniques, such as UV, IR, and NMR, were used to characterize the structures of the isolated compounds 1-7. All the isolated pure compounds (1-7) were tested for their antimicrobial potential. Compounds 1 (4',8-dimethoxy-7-hydroxyisoflavone), 6 (5,3',3-trihydroxy-7,4'-dimethoxyflavanone), and 7 (5',7,8-trihydroxy-6,3',4'-trimethoxyflavanone) were found to be more active against Staphylococcus aureus and Salmonella Typhi. Compound 1 inhibited S. typhi and S. aureus to 10 ± 0.21 mm and 10 ± 0.45 mm, whereas compound 6 showed inhibition to 10 ± 0.77 mm and 9 ± 0.20 mm, respectively. Compound 7 inhibited S. aureus to 6 ± 0.36 mm. Compounds 6 and 7 showed significant antibacterial potential, and the structure-activity relationship also justifies their binding to the bacterial enzymes, i.e., beta-hydroxyacyl dehydratase (HadAB complex) and tyrosyl-tRNA synthetase. Both bacterial enzymes are potential drug targets. Further, the isolated compounds were found to be active against the tested fungal strains. Whereas docking identified compound 7, the best binder to the lanosterol 14α-demethylase (an essential fungal cell membrane synthesizing enzyme), reported as an antifungal fluconazole binding enzyme. Based on our isolation-linked preliminary structure-activity relationship (SAR) data, we conclude that O. chitralicum can be a good source of natural compounds for drug development against some potential enzyme targets.

Nettle-Leaf Extract Derived ZnO/CuO Nanoparticle-Biopolymer-Based Antioxidant and Antimicrobial Nanocomposite Packaging Films and Their Impact on Extending the Post-Harvest Shelf Life of Guava Fruit.

Green synthesized metal oxide nanoparticles (NPs) have prominent applications in antimicrobial packaging systems. Here we have attempted for the fabrication of chitosan-based nanocomposite film containing Urtica dioica leaf extract derived copper oxide (CuO) and zinc oxide (ZnO) NPs for shelf-life extension of the packaged guava fruits. Electron microscopy and spectroscopy analysis of the CuO and ZnO NPs exhibited nano-scale size, spherical morphologies, and negative ζ-potential values. The NPs possessed appreciable antioxidant and antimicrobial activity (AMA) in order of CuO NPs > ZnO NPs >nettle extract. Therefore, this work establishes for the first time the successful synthesis of CuO NPs and compares its antimicrobial and antioxidant properties with ZnO NPs. On incorporation in chitosan, the polymer nanocomposite films were developed by solvent casting technique. The developed films were transparent, had low antioxidant but substantial AMA. The NP supplementation improved the film characteristics as evident from the decrease in moisture content, water holding capacity, and solubility of the films. The nanocomposite films improved the quality attributes and shelf life of guava fruits by one week on packaging and storage compared to unpackaged control fruits. Therefore, this study demonstrates the higher antimicrobial potential of the nettle leaf extract derived CuO/ZnO NPs for development of antimicrobial nanocomposite films as a promising packaging solution for enhancing the shelf life of various perishable fruits.

Establishment and elicitation of transgenic root culture of Plantago lanceolata and evaluation of its anti-bacterial and cytotoxicity activity.

Hairy root induction in Plantago lanceolata was optimized to take advantage of transformed root cultures. The highest frequency of transformation was achieved using leaf explant, A4 strain, pre-cultivation of explant, 150 µM Acetosyringone, 5 min inoculation, half-strength Murashige and Skoog basal medium as co-cultivation, and half-strength Gamborg's basal medium as a selective medium with 3% sucrose. Among the studied compound encompassing gallic acid, catalpol and apigenin, only the production of gallic acid in hairy roots was affected by 20 mg L-1 AgNO3 and 100 mg L-1 chitosan at 24 hr which yielded 7.63, 4.76-fold increase in its content, respectively. The methanolic extracts of hairy roots elicited by 20 mg L-1 AgNO3 exhibited anti-bacterial activity (MIC and MBC = 25 mg mL-1) against Klebsiella pneumoniae, Proteus vulgaris and Salmonella typhi and anti-bacterial potential of non-elicited hairy roots of P. lanceolata (MIC = 25 mg mL-1 and MBC = 35 mg mL-1) were more active against Klebsiella pneumoniae and P. vulgaris than other bacteria. The methanolic extracts of the P. lanceolata hairy roots demonstrated significant cytotoxic activity on colorectal carcinoma cell line (SW-480) with IC50 = 250.65 ± 6.8 µg mL-1 in comparison to human embryonic kidney (HEK-293) with IC50 = 5263.65 ± 4.6 µg mL-1. Plantago lanceolata hairy roots showed important biological activity explaining its role in traditional medicine.

The first imported case of extensively drug-resistant Salmonella enterica serotype Typhi infection in Taiwan and the antimicrobial therapy.

The first imported case of XDR typhoid fever in Taiwan contracted with a bacterial strain, which was most closely related to the blaCTX-M-15-carrying strains linked to Pakistan. Meropenem, in combination with an antimicrobial with intracellular activity against Salmonella, should be used for the treatment of XDR typhoid fever.

Screening of the Dichloromethane: Methanolic Extract of Centella asiatica for Antibacterial Activities against Salmonella typhi, Escherichia coli, Shigella sonnei, Bacillus subtilis, and Staphylococcus aureus.

Bacterial infections are responsible for a large number of deaths every year worldwide. On average, 80% of the African population cannot afford conventional drugs. Moreover, many synthetic antibiotics are associated with side effects and progressive increase in antimicrobial resistance. Currently, there is growing interest in discovering new antibacterial agents from ethnomedicinal plants. About 60% of the population living in developing countries depends on herbal drugs for healthcare needs. This study involved the screening of Centella asiatica commonly used by herbal medicine practitioners in Kisii County to treat symptoms related to bacterial infections. Standard bioassay methods were applied throughout the study. They included preliminary screening of dichloromethane: methanolic extract of Centella asiatica against human pathogenic bacteria including Salmonella typhi ATCC 19430, Escherichia coli ATCC 25922, Shigella sonnei ATCC 25931, Bacillus subtilis ATCC 21332, and Staphylococcus aureus ATCC 25923 using agar disc diffusion, broth microdilution method, and time-kill kinetics with tetracycline as a positive control. Phytochemical screening was carried out to determine the different classes of compounds in the crude extracts. Data were analyzed using one way ANOVA and means separated by Tukey's test. Dichloromethane: methanolic extract of Centella asiatica was screened against the selected bacterial strains. Time-kill kinetic studies of the extracts showed dose- and time-dependent kinetics of antibacterial properties. Phytochemical screening of the DCM-MeOH extract revealed the presence of alkaloids, flavonoids, phenolics, terpenoids, cardiac glycosides, saponins, steroids, and tannins. The present study indicates that the tested plant can be an important source of antibacterial agents and recommends that the active phytoconstituents be isolated, identified, and screened individually for activities and also subjected further for in vivo and toxicological studies.

Antimicrobial Potential of Essential Oils from Cerrado Plants against Multidrug-Resistant Foodborne Microorganisms.

Foodborne pathogens are a real public health concern in an escalating antimicrobial resistance scenario. Natural products represent a promising source of bioactive molecules, and essential oils have attracted much attention due to their myriad of biological properties, including antibacterial activities. In this context, essential oils obtained from the leaves of Chromolaena squalida, Campomanesia sessiliflora, Myrsine guianensis, Matayba guianensis, Siparuna guianensis, Ocotea minarum and Endlicheria paniculata-species from the Cerrado biome of Midwest Brazil-were extracted and evaluated for their antibacterial activity against a panel of four standard and three clinical multidrug-resistant bacterial strains. All tested oils showed moderate to good activity against at least four bacterial strains, including Salmonella Typhi and oxacillin-resistant Staphylococcus. The essential oils from C. squalida, C. sessiliflora, My. guianensis and Ma. guianensis showed strong inhibition of clinical Staphylococcus strains, which cause bovine mastitis and are related to milk-borne diseases. Their chemical profiles were investigated by gas chromatography coupled to mass spectrometry (GC/MS), which revealed a predominance of mono- and sesquiterpene hydrocarbons, some of which with well-known antimicrobial properties. The essential oil from Cerrado plants proved active against resistant Gram-positive and Gram-negative bacteria, revealing their potentialities for the development of new alternative agents to prevent the spreading of resistant bacterial contamination.

Evaluation of Anticancer, Antibacterial and Antioxidant Properties of a Medicinally Treasured Fern Tectaria coadunata with its Phytoconstituents Analysis by HR-LCMS.

BACKGROUND: Tectaria coadunata (T. coadunata) is an important fern species with a number of medicinal properties. It has been evidently found for its effectiveness in ethanomedicinal usage, which can also emerge as one of the most promising sources for nutraceuticals. OBJECTIVE: This study aims to examine the phytochemistry of the whole crude extract of T. coadunata for the first time with evaluation of antibacterial, antioxidant and anticancer activity. METHODS: High Resolution Liquid Chromatography Mass Spectrometry analysis (HR-LCMS) was performed for confirming the presence of biologically active constituents in the extract of T. coadunata followed by antibacterial, antioxidant and anticancer activity. RESULTS: With the detailed Mass spectra data, absorbance spectra and retention times, chemical composition of T. coadunata holds a diverse group of bioactive/chemical components such as sugars, sugar alcohol, flavonoids, terpenoids and phenolics. The results for antioxidant activity showed that T. coadunata crude extract had higher scavenging potential against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals than H2O2 molecules, which was followed by positive antibacterial activity against several pathogenic bacteria like Shigella flexneri, Staphylococcus aureus and Salmonella typhi. DISCUSSION: The ethanolic extract of T. coadunata showed favorable antiproliferation activity against three leukemic (KG1, MOLT-3 and K-562) cells in a dose dependent manner, especially for KG1 42.850±1.24µg/ml. CONCLUSION: This study has provided a better understanding of the presence of biologically active phytochemical constituents in the extract of T. coadunata, which can be the reason for its bioactive potential. Moreover, T. coadunata has significant anticancer activities against human leukemic cancer cell lines, indicating it as a potential anticancer agent.

High-dose Dexamethasone in a Child With Enteric Encephalopathy Caused by Salmonella enterica serovar Typhi.

Increased antimicrobial resistance to Salmonella species threatens successful treatment of typhoid and other infectious diseases. Consequently, rare complications arising from incompletely treated typhoid could increase in frequency. We describe a case of enteric encephalopathy caused by Salmonella enterica serovar Typhi and the utility of adjunct treatment with corticosteroids.