Bacteria Shigella Dysenteriae Research Articles

Rapid detection of ESKAPE and enteric bacteria using tapered dielectrophoresis and their presence in urban water cycle

ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) and enteric bacteria Shigella dysenteriae, Salmonella typhimurium and Escherichia Coli have been causing increasing nosocomial infections worldwide, contributing to high mortality and morbidity in surgical wards. This study attempts to investigate the feasibility of dieletrophoresis (DEP) electrode in detecting both ESKAPE and enteric bacteria in water samples. The detection is based on the bacteria's response to the non-uniform electric field in micro tapered DEP electrode and microfluidic chamber. Responses of each bacterium were recorded by varying the frequency of sinusoidal 6 voltage (peak to peak) from 10 to 13,000 kHz. Utilising the unique electrokinetic responses of each bacterium, the performance of DEP application is assessed in detecting the ESKAPE and enteric bacteria from samples within the urban water cycle, i.e., wastewater, river, runoff, and treated water from an urbanised developed area. The positive (PDEP), negative (NDEP) and transitional, (denote as the crossover frequency fx0) responses for each bacterium were consistently determined, spanning between 52.3 and 12,000 kHz. DEP technique was successfully able to detect ESKAPE and enteric bacteria from water samples, where water from the river proved to be the most microbially contaminated in urban water cycle.

ANTIBACTERIAL ACTIVITY OF BIDARA LEAVES (Ziziphus mauritiana L.) ETHANOL EXTRACT AGAINST SOME TEST BACTERIA

ABSTRACTBidara leaves (Ziziphus mauritiana L.) are one of the traditional plants that contain antibacterial compounds such as alkaloids, flavonoids, saponins, tannins and phenols. This study aimed to determine the antibacterial activity of the ethanol extract of bidara leaves (Ziziphus mauritiana L.) against several test bacteria using the agar diffusion method. This test begins with a screening test using 10 test bacteria and the result is inhibiting the growth of bacteria at a concentration of 0.1%. Then the MIC test was carried out and the result was that a concentration of 0.1% could inhibit and kill the growth of the test bacteria. Then the KBM test was carried out and the results obtained at a concentration of 12.8% could inhibit and kill Eschercia coli and Pseudomonas aeruginosa bacteria, a concentration of 6.4% could inhibit and kill Staphylococcus epidermidis and Vibrio cholerae bacteria, a concentration of 3.2% could inhibit and kill bacteria Staphylococcus aureus, Bacillus sublitis and Streptococcus mutans, a concentration of 1.6% can inhibit and kill Salmonella typhi and Propionibacterium acnes bacteria, and a concentration of 0.8% can inhibit and kill Shigella dysenteriae bacteria. Then, the antibacterial activity of the ethanol extract of bidara leaves (Ziziphus mauritiana L.) was tested using the agar diffusion method and the results showed that the ethanolic extract of bidara leaves (Ziziphus mauritiana L.) had strong potential as an antibacterial against test bacteria with the largest diameter of the inhibition zone at a concentration of 12 ,8% by 15.64 mm.Key Words: Antibacterial, Bidara Leaf (Ziziphus mauritiana L.), Agar diffusion

Antibacterial activity of β-Sitosterol from Ketapang kencana stem (Terminalia mantaly)

The genus of Terminalia is widespread in southern Asia, the Himalayas, Madagascar, Australia and Africa. The composition of chemical compounds from the genus of Terminalia consists of terpenoids, tannins, flavonoids, lignans, phenols and glycosides often used in Ayurveda and drugs. β-sitosterol compounds have been isolated from the n-hexane extract of the stems of Ketapang Kencana (T. mantaly) through various chromatographic methods. The chemical structure was identified based on IR, UV spectroscopy, 1H-NMR, 13C-NMR and NMR 2D. The antibacterial activity of n-hexane extract and β-sitosterol compounds was carried out on positive gram bacteria (Staphylococcus aureus, Streptococcus pyogenes) and negative gram bacteria (Shigella dysenteriae and Escherichia coli). The value of the minimum inhibitory concentration (MIC) for extracts and isolates was 0.5 mg/mL respectively.

Studies on evaluation of antibacterial activities of some cultivated mushrooms against human pathogenic bacteria

Mushrooms have been used as source of nutritive food and medicine since ancient time. The indiscriminate utilization of modern antibiotic drugs has caused the development of multiple drug resistance in pathogenic microbes. The antimicrobial properties of herbs and mushrooms have proved to be fruitful in getting rid of from the problem of multiple drug resistance. In this study, the antibacterial activity of acetone, aqueous and methanol extracts of Agaricus bisporus, Calocybe indica, Flammulina velutipes, Pleurotus florida, and Volvariella volvacea were investigated against human pathogenic bacteria. The antimicrobial activity  of these mushrooms were evaluated following the agar well diffusion method against Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes and gram negative bacteria Shigella dysenteriae, Salmonella typhi and Escherichia coli. All the studied mushrooms displayed considerable antibacterial activity against all the pathogenic bacteria under study and it was found to be extraction solvent dependent. The zones of growth inhibition of 12.26-14.80 mm in Agaricus bisporus, 12.84-15.31mm in Calocybe indica, 13.82-16.17 mm Flammulina velutipes, 12.2-14.80 mm in Pleurotus florida, and 12.34-15.84 mm in Volvariella volvacea were recorded in acetone extract. The zones of growth inhibition of 10.73-11.23 mm in Agaricus bisporus, 10.63-12.62 mm in Calocybe indica, 12.50-13.84 mm Flammulina velutipes, 11.14-11.97 mm in Pleurotus florida, and 11.51-12.31 mm in Volvariella volvacea were observed in aqueous extract. The zone of inhibition observed in methanol extract were 13.06-14.93 mm in Agaricus bisporus, 11.96-14.01 mm in Calocybe indica, 12.01-13.41 mm Flammulina velutipes, 13.02-13.74 mm in Pleurotus florida, and 13.32-15.21 mm in Volvariella volvacea. The minimum inhibitory concentration (MIC) of acetone extract ranged from 0.3125 µg/100µl-0.625 µg/100µl, aqueous extract 0.625 µg/100µl-2.5 µg/100µl and methanol extract 0.3125 µg/100µl-1.25 µg/100µl. The results emphasize that there is a need for further studies to isolate and characterize the bioactive compounds present in these cultivated mushrooms so that their antibacterial potential can be used to develop effective drugs against these human pathogenic bacterial strains.Keywords: Mushrooms, antibacterial, minimum inhibitory concentration, zone of inhibition.

Antibacterial activities of zinc oxide nanoparticles: a mini review

Highly reactive oxygen species (ROS) are released from the surface of zinc oxide nanoparticles (ZnO NPs) which cause damage to the microorganisms. ROS may break down the cell wall and cell membrane of the bacteria leading to the leakage of cell contents causing their death. Antibacterial effect of ZnO NPs synthesized from plants’ extracts has been seen against several grampositive (Bacillus coagulans, Staphylococcus aureus, Bacillus subtilis) and gramnegative bacteria (Shigella dysenteriae, Sphingomonas paucimobilis, Salmonella typhimurium, Escherichia coli, Bacillus pumilus, Salmonella typhi). Zinc ions (Zn2+) freed from ZnO NPs may attack DNA and proteins of the cell, thus hindering the growth of the bacteria. The negative charge on the surface of some bacteria (E. coli, S. typhi) interacts with positively charged particles in ZnO NPs inhibiting the growth of these bacteria. The rate of antibiotic activity of ZnO NPs depends on size, the concentration of ZnO NPs, and the type of surfactant used in the synthesis of these ZnO NPs. Due to their antibiotic property, ZnO NPs can be used as antibacterial coating of inner surfaces of refrigerators and dishwashers, plastic food containers, in the lining of food cans used for packaging and preservation of food to prevent their spoilage.

UJI AKTIVITAS EKSTRAK ETANOL KOMBINASI DAUN PANDAN WANGI DAN DAUN JAMBU BIJI TERHADAP Shigella dysenteriae

Dysentery can be treated using Pandanus amarylifolius leaves and Psidium guajava leaves. This study aimed to determine the activity of the combination of 96% ethanol extract of P. amarylifolius leaves and P. guajava leaves in inhibiting the growth of Shigella dysenteriae bacteria. Methods. Extraction of P. amarylifolius leaves and P. guajava leaves respectively by using the maceration method with 96% ethanol solvent. For the combination treatment, each of these extracts was combined. Each extract obtained was tested for minimum inhibitory concentration (MIC). The MIC value of P. amarylifolius leaf extract was obtained at a concentration of 30% and P. guajava leaf extract was obtained at a concentration of 40%. Inhibitory width test (IWT) by disc diffusion method was carried out on single extracts and combination extracts, with treatment concentrations of 30% single extract of P. amarylifolius leaf (K1), 40% single extract of P. guajava leaf (K2), combination 1 (P. amarylifolius leaf). 30%+ P. guajava leaf 40%) (K3), combination 2 (35% P. amarylifolius leaf + 40% P. guajava leaf) (K4), combination 3 (40% P. amarylifolius leaf + 40% P. guajava leaf) (K5). The width of the inhibition of the research results of the treatment against S. dysenteriae were analyzed using a completely randomized design and Duncan's test. The results showed that the combination of P. amarylifolius leaf extract and P. guajava leaf was more effective in inhibiting the growth of S. dysenteriae bacteria. The combination of P. amarylifolius leaf extract and P. guajava leaf extract that was most effective in inhibiting the growth of S. dysenteriae bacteria was combination 3 (40% P. amarylifolius leaf extract + 40% P. guajava leaf extract) with an average inhibitory width of 5.625 mm. Keywords: Combination, P. amarylifolius Leaves, P.guajava Leaves, S. dysenteriae

Bimetallic Fe/Mn MOFs/MβCD/AuNPs stabilized on MWCNTs for developing a label-free DNA-based genosensing bio-assay applied in the determination of Salmonella typhimurium in milk samples

Monitoring of pathogenic bacteria plays a vital role in precluding foodborne disease outbreaks. In this research work, a genosensor based on innovative label-free DNA was developed for the detection of Salmonella. typhimurium (S. typhimurium) in the milk samples. To realize this objective, bimetallic Fe/Mn MOF is synthesized and mixed with methyl-β-cyclodextrin (MβCD) and AuNPs which are then stabilized on multi-walled carbon nanotubes (MWCNTs), and the obtained nanocomposite is immobilized on the Au electrode surface. Different characterization methods such as FE-SEM, TEM, EDS, FTIR, and XRD were used for investigating the particle size and morphological features. Electrochemical and impedimetric techniques were used for exploring the applicability of the fabricated genosensor. Under optimal circumstances, LOD and LOQ have acquired at 0.07 pM and 0.21 pM. Moreover, an extensive linear range of 1 pM−1 μM was resulted for ss-tDNA (single-stranded target DNA), R2 obtained 0.9991. The recoveries were obtained 95.6–104%. Great selectivity against one, two, and three-base mismatched sequences was also shown for fabricated biosensing assay. Furthermore, negative genosensing assay control for investigating selectivity was provided by the ss-tDNAs of Haemophilusinfluenzae and Shigella dysenteriae bacteria. Well-fabricated genosensing bio-assay represents better performance, great specificity, high sensitivity, increased active sites, and finally results in an increase in the electron transfer rate. It is to be noted that the organized genosensing bio-assay is capable of being re-used and re-generated in a straightforward manner to estimate the hybridization process.

Identification of Shigella dysenteriae on Salad Food in Denpasar City

Shigella dysenteriae is a global disease-causing bacteria that has millions of infections every year. Direct human-to-human transmission, spread due to contamination of food and beverages, low susceptibility to stomach acid and vector contribution can cause disease caused by Shigella dysenteriae to be widespread. Salad is a food that is prone to contamination by the Shigella dysenteriae bacteria if it does not pay attention to the hygiene process before processing, during processing and selling. The purpose of this study was to determine the percentage of Shigella dysenteriae contamination in salad food in Denpasar City. Design of this study is a descriptive study with cluster purposive sampling technique and obtained 12 salad samples that meet the inclusion criteria. The sampling process was carried out using aseptic techniques for all samples taken from wrong traders in 4 areas of Denpasar City. After the sample collection was complete, a test for the presence of Shigella dysenteriae was carried out at the Microbiology Laboratory of FK Unud by culture of SSA media culture, oxidase test and identification test at the Nikki Medika Laboratory Denpasar using the BD Phoenix M50 method. The results showed that of the 12 salad samples studied, none of the samples identified were Shigella dysenteriae (0%), but Pluralibacter gergoviae, Leminorella grimontii, and Pantoea agglomerans were identified which is not a dangerous pathogenic bacteria. The negative results found were due to the good level of sanitation and hygiene applied by the salad traders.
 Keywords : Contamination of Shigella dysenteriae, Shigella dysenteriae, Salad.

The Relationship between Structure and Binding Effect of Shiga Toxin

Shiga toxin is an exotoxin protein. Shiga toxin is produced by the bacterium Shigella dysenteriae, or a similar one produced by E. coli, causing dysentery in humans. The motivation of this work is to explore the functions of the toxin through its structure. The Shiga toxin is a AB5 toxin that binds to specific receptors that are located on the cells’ surface to enter the cell. Transmission is from species such as swine, cattle, and deer that harbor toxigenic bacteria without syndromes but can be spread to humans through them shedding the toxin onto their feces. The Shiga toxin is an AB5 toxin, meaning the B subunit has the role of binding to cellular receptors, globotriaosylceramide (Gb3) or a glycoprotein which is located primarily on the surface of endothelial cells. Due to its structure, the Shiga toxin is unique for its highly selective receptors that allows the toxin to kill cells whether they are healthy or cancerous cells. With further research our team hopes to learn more about its functions and explore the possible benefits of the toxin.

Perbandingan Uji Aktivitas Antibakteri Umbi Bawang Merah (Allium Cepa L) Dan Umbi Bawang Putih (Allium Sativum) Terhadap Pertumbuhan Bakteri Shigella Dysenteriae

Background :Diarrhea is one of the causes of morbidity and mortality in infants and children around the world. One of the causes of diarrhea is Shigella sp bacteria or shigellosis. Nowadays, many antibiotics resistant to the Shigella sp bacteria are one example of chloramphenicol, so it is necessary to have other alternatives such as natural ingredients. Objective: Determine the activity of the red onion (Allium cepa L) and garlic (Allium sativum), which is known to possess antibacterial phytochemical compounds against the Shigella dysenteriae bacteria. Method: This research is a laboratory experimental study to determine antibacterial activity using the Kirby-Bauer or diffusion method of discs and to determine the presence of Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC). The study uses five treatments i.e., onion extracts and garlic extracts with a concentration of 30%, 40%, 50%, 60%, 70%, control positive (Ciprofloxacin), and negative control (aquadest). Results: Red onion diffusion has the best antibacterial activity at concentrations 70% while garlic has the best antibacterial activity at a concentration of 70%. In this study, there were no MIC and MBC. The MIC data analyzed with the crucial test of Kruskal-Wallis (p 0.05) i.e., in onion extract p = 0.003 and in garlic P = 0.003, which means significant. The MBC Data is analyzed by crucial test (P 0.05) in the onion extract p = 0.003 and on garlic p = 0.04. Conclusion : the disc diffusion and the MBC can be concluded that garlic extract can inhibit the growth of S. dysenteriae compared to red onion extracts. onion extracts).

UJI DAYA HAMBAT EKSTRAK DAUN CENGKEH (Syzygium aromaticum (L.) Merr. & L. M Perry.) TERHADAP PERTUMBUHAN BAKTERI Shigella dysenteriae

Research about the inhibitory test of Syzygium aromaticum leaf extract on the growth of Shigella dysenteriae bacteria which aims to determine the effectiveness of S. aromaticum leaf extract in inhibited the growth of S. dysenteriae bacteria, knowing the concentration of leaf extract is effective in inhibited the growth of S. dysenteriae bacteria and the content of flavonoid compounds, saponins, tannins and alkaloids contained in leaves S. aromaticum, has been conducted from July until December 2016. Extraction method used is Maseration method. Inhibitory test extract on S. dysenteriae bacteria using disc diffusion method. This research was arranged in Completely Randomized Design with 6 treatments and 3 repetitions with extract concentration 30%, 45%, 60% and 75% and 2% Cotrimoxazole antibiotics as positive controls and Aquades as negative controls. The results showed that 75% extract concentration of S. aromaticum plant produced the largest drag zone compared to other concentrations of 17 mm. This indicates that S. aromaticum leaf extract has good inhibitory ability against S. dysenteriae bacteria.

Toxicology studies and antibacterial activities of the ethyl acetate extract of Piliostigma reticulatum

The ethyl acetate extract of Piliostigma reticulatum was evaluated for its antibacterial activity against pathogenic clinical bacteria (Shigella dysenteriae, Escherichia coli, Streptococcus pyogenes and Staphylococcus aureus) using the agar well diffusion method. The comparative antibacterial effect was also investigated using standard antibiotics. Multiple antibiotic resistance index was determined using standard methods. The phytochemical components of the plant were also investigated. The in-vivo acute toxicity study was carried out on cell lines of Wister rat. The phytochemical screening was carried out. The antibacterial test showed the plant extract to be active against all the test organisms at 100mg/ml with zones of inhibition of 20 mm, 16 mm, 18 mm and 16 mm against S. dysenteriae, E. coli, S. pyogenes and S. aureus respectively. The antibiotic sensitivity test showed E. coli to have 61% susceptibility, while S. pyogenes had 23% and S. aureus had 7.6% susceptibility while S. dysenteriae had 100% resistance. MAR index revealed all the test bacteria to a have a high level of resistance to standard antibiotics. Phytochemical components include alkaloids, glycosides, steroids, phenol, tannin and saponin. Toxicology studies showed no mortality, no changes in the physical appearances, tremor or salivating. The rats appeared active after treatment as compared with the control with no apparent loss of weight. The biochemical analysis also revealed no significant difference in data obtained as compared to the control. Haematological parameters also showed no significant differences in values as compared to the control. There were obvious organ damages as observed in the histological gross assessment of the cross section of the organ (kidney, liver and intestine) which include gross distortion of the architecture, haemorrhaging, and congestion of vessels. However, tolerance on the part of the experimental animals prevented mortality and physical manifestation of organ damage. The result thus obtained in this work evidenced that P. reticulatum is toxicologically safe and biologically active against test organisms and hence be considered as a candidate in antibacterial drug formulation.

Impact of different transition metal ions in the structural, mechanical, optical, chemico-physical and biological properties of nanohydroxyapatite

Pure and metal ions (iron, manganese, cobalt) doped nanosized hydroxyapatite [Ca10(PO4)6(OH)2 or HAP] were prepared by wet-chemical precipitation technique. XRD patterns confirm that all the synthesized samples are single phase HAP. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) clearly showed the hexagonal and spherical morphology of the samples. X-ray photoelectron spectroscopy (XPS) confirmed that Fe2+, Mn2+, and Co2+ are substituted in HAP separately, and it also confirmed their oxidation state. The ac conductivity increases with the rise in frequency for all the samples. Among all dopants, 1% Fe doped HAP shows both the highest ac conductivity and the lowest impedance. The ac conductivity of the samples is in the order of 10−6 S/m, and it remains the insulating nature of the pure and doped HAP. The diamagnetic nature of the HAP changed into superparamagnetic due to the addition of dopant. The antibacterial activity of chosen samples depends on the types of bacterial strains and the dopant concentration. Among the different dopants 5% cobalt doped HAP revealed the highest antibacterial activity against Shigella dysenteriae bacteria.

Antibacterial Activity of Allium ascalonicum Linn Fractions A562275sal from the Palu Valley against Shigella dysenteriae

Shallot (Allium ascalonicum Linn.) is one of the typical plants of Central Sulawesi which is used as traditional medicine such as to treat infectious diseases. This study aims to determine the fractions that have high activity from bulbs and leaves in inhibiting the growth of Shigella dysenteriae bacteria and determining the organic compounds that have antibacterial activities. Extraction was carried out by maceration method using ethanol 96% for both samples. Liquid-liquid fractionation was used as a fractionation method using hexane, ethyl acetate and water solvents, sequenly. The antibacterial activity test used the diffusion method with the pile technique and TLC-bioautography. The results showed that ethyl acetate fraction gave the highest activity of bulbs samples, while in leaves samples ethyl acetate fraction and hexane fraction were able to provide good inhibitory activity. The organic compounds were identified by thin layer chromatography method. Flavonoids compounds have identified for bulbs samples (Rf 0.18). In the leaves samples, steroids compounds were identified in the ethyl acetate fraction (Rf 0.62) and terpenoid compounds (Rf 0.48) in the hexane fraction. Based on the result, the shallot is potentially be developed as an antibacterial material.

Synthesis, physical characterization, and antifungal and antibacterial activities of oleic acid capped nanomagnetite and cobalt-doped nanomagnetite

Nanoparticles, 10–14 nm, consisting of either Fe3O4or Co0.2Fe2.8O4stabilized with oleic acid, were prepared using solution combustion. Their structural and magnetic properties were examined using X-ray diffractometry, scanning electron microscopy, vibrating sample magnetometry, and Fourier-transform infrared spectroscopy. The properties of both sets of materials are similar, except that the cobalt-doped particles are considerably less magnetic. The in vitro inhibitory activities of the nanoparticles were assessed against pathogenic bacteria Shigella dysenteriae, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus pyogenes, and pathogenic fungi and molds Candida albicans, Fusarium oxysporum, and Aspergillus fumigatus. The magnetite nanoparticles were moderately effective against all tested pathogens, but the activity of the cobalt-doped nanoparticles was significantly lower, possibly due to an interruption of the Fenton reaction at the bacterial membrane. This work suggests that potentially doping magnetite with stronger metal oxidants may instead enhance their antimicrobial effects.

Evaluation on antibacterial activity of Karamunting leaf extract (Rhodomyrtus tomentosa (Ait) Hassk) with various solvents to Shigella dysenteriae and Salmonella typhi

Traditionally, Karamunting plants ( Rhodomyrtus tomentosa (Ait) Hassk) are used to treat several types of infectious diseases, such as diarrheal diseases. Dysentery and typhoid fever are still common in developing countries. Dysentery is caused by the bacterium Shigella dysenteriae and typhus is caused by Salmonella typhi . This study aimed to evaluate n-hexane, ethyl acetate and ethanol extracts from Karamunting leaf as antibacterial dysentery and typhus. The extract concentrations tested were, 4000, 2000, 1000, 500, 250 and 125 μg/mL. Extraction was carried out in a Soxhlet tool in stages, starting with n-hexane, ethyl acetate and ethanol solvents. Antibacterial activity test was conducted by using the agar diffusion method. The study showed that n-hexane and ethyl acetate extracts were active against the test bacteria while the ethanol extract was inactive. The Minimum Inhibit Concentration (MIC) value of n-hexane and ethyl acetate extracts against S. dysenteriae and S. typhi bacteria was 250 μg/mL. N-hexane and ethyl acetate extracts contained phenol and flavonoid compounds. Karamunting leaf has the potential to be developed into dysentery and typhoid drugs.

Daya Hambat Ekstrak Biji Ketumbar (Coriandrum Sativum L) Terhadap Pertumbuhan Bakteri Shigella Dysenteriae Metode Cakram

Coriander seed (Coriandrum Sativum l.) is a plant that originated in the Mediterranean, and the Middle East, Indonesia society generally in stead right as a condiment Cook. Coriander seed is often also used for diabetes, diuretic, hypolipidemia, anti-fungal, bacterial or yeast either antibiotic, antioxidan, and anti-inflammatory. Extraction of coriander seeds is carried out by means of maceration using solvent ethanol 70%. The current concentration of 50% used, 75%, and 100%, with positive control (cotrimoxazole 5 µ g/50 µ l) and negative control (aquadest sterile). The test is performed twice with disc diffusion method of repetition. Phytochemical screening extracts of coriander seeds showed the presence of compounds alkaloids, saponins, tannins, flavonoids, phenolic, Triterpenoid, and glycosides. The test results showed that extracts of coriander seeds capable of inhibiting growth bacteria shigella dysenteriae. Coriander seed extract which is able to inhibit the growth of bacteria of the shigella dysenteriae is the concentration of 100% and an average of 8.7 mm in diameter with drag power belongs belongs to the medium.

Uji Aktivitas Antibakteri Ekstrak Kasar Bawang Putih (Allium sativum ) terhadap Bakteri Shigella dysenteriae yang Resisten terhadap Ampisilin

ABSTRACT Background : Gastrointestinal infections, especially caused by Shigella dysenteriae bacteria is still a health issue in Indonesia. The number of ampicillin resistance to S. dysenteriae has been widely reported. Garlic (Allium sativum) is a traditional medicine that efficacy as an antibacterial. Garlic contains an organosulfur compound Allicin. Research Purpose: This study aimed to determine the antibacterial activity of garlic rule extract on the growth of S. dysenteriae bacteria that are resistant to ampicillin. Research Methods: This study used the experimental with post test only control group design. The antibacterial activity test was determined based on the diameter of clear zone formed. Test were performed on garlic filtrate, ciprofloxacin as a positive control and aquades as a negative control. Each treatment was performed three times. Research Result: This research showed that rule extract of garlic (A. sativum) had a clear zone against S. dysenteriae that was resistant to ampicillin. Conclusion: The conclusion of this research was that rule extract of garlic (A. sativum) had an antibacterial activity against S. dysenteriae which resistant to ampicillin. Keywords : Antibacterial activity, Garlic (A. sativum), S. dysenteriae

Characterization of silver nanoparticle produced by Pseudopediastrum boryanum (Turpin) E. Hegewald and its antimicrobial effects on some pathogens

The aim of this research was to investigate the antimicrobial activity of silver nanoparticles (AgNPs) biosynthesized by Pseudopediastrum boryanum (Turpin) E. on several human pathogen microorganisms. AgNPs were isolated from P. boryanum. The biosynthesis of AgNPs was carried out using a UV–visible spectrophotometer and FTIR spectroscopy analysis. The antimicrobial activity of AgNPs was evaluated against various pathogen microorganisms using the well diffusion method, and MIC was estimated by qualitative experimentation by microbroth dilution method. The antimicrobial activities of AgNPs at three different concentrations (1 mM, 2 mM and 3 mM) were measured using the diameter of the inhibition zone (DIZ) of the pathogen microorganisms. AgNPs demonstrated various antimicrobial effects on pathogen microorganisms at different concentrations. The highest antimicrobial activity was determined in Proteus vulgaris [DIZ = 30 ± 0.2 mm (2 and 3 mM)], followed by Candida parapsilosis (M006) [DIZ = 25 ± 0.1 mm (3 mM)], followed by Pseudomonas aeruginosa [DIZ = 20 mm (2 and 3 mM)] and Candida parapsilosis (M006) [DIZ = 20 mm (1 and 2 mM)]. The lowest antibacterial effects of AgNPs were observed on Aeromonas hydrophila [DIZ = 5 ± 0.1 mm (3 mM)], Staphylococcus epidermidis [DIZ = 5 ± 0.1 mm (1 mM)], Candida parapsilosis [DIZ = 5 ± 0.1 mm (2 mM)] and Candida albicans [DIZ = 5 ± 0.1 mm (3 mM)]. Gram-negative bacteria Proteus mirabilis, Enterobacter aerogenes, Salmonella typhimurium, Shigella dysenteriae, Escherichia coli and Serratia marcescens and Gram-positive bacteria Listeria monocytogenes and Enterococcus faecalis exhibited no zone of inhibition. Our results confirm that AgNPs biosynthesized from P. boryanum may be used as an effective antimicrobial agent against human pathogens.

Biochemical Characterization of In vitro Reconstituted Biologically Active Recombinant Shiga Toxin.

Shiga toxins comprise a family of related proteins produced by bacteria Shigella dysenteriae and some strains of Escherichia coli that cause severe clinical manifestations. Severe Shiga toxin intoxication results in Haemolytic-Uremic Syndrome (HUS), up to 50% of HUS patients manifest some degree of renal failure and ~10% of such cases develop permanent renal failure or death. In present research work production of biologically active rStx from non-toxic rStxA and rStxB subunits were established that can be used in many biomedical applications. Purification of Shiga toxin from bacteria is a multistep time consuming process resulting in low yield. To overcome this problem, the rStxA and rStxB protein were separately cloned and expressed in E. coli host and purified through affinity chromatography. GST pull-down assay was performed for interaction study between rStxA and pentameric rStxB. The affinity between A and B subunits of reconstituted recombinant Shiga toxin (AB5) was determined by SPR. The biological activity of the toxin was confirmed in Vero cells and mouse lethality assay. The yield of GST-StxA and His6X-StxB obtained after affinity chromatography was estimated to 2 and 5 mg/l, respectively. Samples analyzed in pull down assay revealed two bands of ~58 kDa (rStxA) and ~7.7 kDa (rStxB) on SDS-PAGE. Affinity was confirmed through SPR with KD of 0.85 pM. This rStx produced from 1:5 molar ratio found to be cytotoxic in Vero cell line and resulted lethality in mouse. Large scale production of rStx using the method can facilitate screening and evaluation of small molecule inhibitors for therapeutics development.