Production and Characterization of Pectic Enzymes of Xanthomonas campestris pv. sesami

إنتاج ودراسة خصائص الإنزيمات البكتينية للبكتيريا Xanthomonas campestris pv. sesami   ملخص الدراسة            البكتيريا  Xanthomonas campestris pv. sesami ، هي المسبب لمرض تبقع أوراق نبات السمسم. الأنزيمات البكتينية التي تنتج بواسطة العديد من البكتيريا الممــرضة للنبات اتضـح أنها تلعب دوراً هاماً في عمــلية الأمراض. هنالك ثلاث أنواع رئيـسـية من الإنزيمات البكــتينية (بوليجلاكتيورونيز، PG وبوليجلاكتيورونيت ترانس - امنيز، PTE و بكتين ميثايل - اٍستريز، PME). هـدف هذا البحث على دراسة قدرة البكتيريا، X.  campestris pv. sesami  على إنتاج الإنزيمات البكتينية المختلفة. استخدم في هذه الدراسة وسط غذائي من الأملاح مضافاً إليه مواد بكتينية مختلفة كمصدر للكربون. الإنزيمات المنتجة تمت دراسة خصائصها باستخدام اختبارات محددة. أوضحت النتائج أن البكتيريا كانت قادرة إنتاج الإنزيم بوليجلاكتيورونيت ترانس - اٍمنيز ((PTE فقط ولم تنتج الانزيم بكتين ميثايل - اٍستريز، PME)). أشارت النتائج الى أن ملح بولي بكتات الصوديوم وحمض البولي جلاكتيورونيك  هي الأفضل لإنتاج هذا الإنزيم حيث أعطت  9 .26 و 19.8 وحدات لزوجة إنزيمية، على التوالي. . كان أعلى إنتاج للإنزيم في اليوم السادس (9.3 وحدات لزوجة)  ثم انخفض الإنتاج مع زيادة فترة التحضين. اختبار تأثير درجة الأس الهيدروجيني أوضح أن الدرجة المثلى لنشاط  الإنزيم كانت 9.0. أظهرت دراسة اختبار تاثيز ايونات لمعادن مختلفة على نشاط الانزيم أن أيونات الكالسيوم هي التي أعطت اكبر نشاط 12.2  وحدة لزوجة. وعند اختبار تراكيز مختلفة من  ايونات الكالسيوم ووجد ان اعلى نشاط كان على التركيز  50 ملج / مل حيث أعطى 18.0 وحدة لزوجة. توصي الدراسة على اختبار قدرة البكتيريا على انتاج إنزيمات السليولوز وشبه السليولوز والتي لها دور ايضاً في عملية الاٍمراض.       The bacterium Xanthomonas campestris pv. sesami, is the causal organism of the leaf spot disease (Marad eldum) in sesame plants. Pectic enzymes which were reported to be produced by many plant pathogenic bacteria,  were found to play an important role in pathogenesis. There are three main types of pectic enzymes (Polygalacturonase, PG, Polygalacturonate trans-eliminase PTE and Pectin methylesterase PME). The present study was conducted to investigate the capacity of the bacterium X. campestris pv. sesami,  to produce the different types of pectic enzymes. A salt medium supplemented with different pectic materials as carbon sources were tested for the production of the enzymes. The produced enzymes were characterized using different selective tests, both the viscosity and reducing group methods were used to measure the enzyme activity. The results showed that no pectin methylestrease (PME) was produced and only the Polygalacturonase trans-eliminase (PTE) was produced by the bacterium. Sodium polypectate and polygalacturonic acid were found as the best substrates giving 26.9 and 19.8 viscosity enzyme units, respectively. The enzyme activity was maximum at the 6th day (9.3 viscosity units), then the activity was decreasing with further incubation time. The test of the effect of the pH indicated that the  pH optimum of the enzyme activity was at pH 9.0. The effects of different metallic ions to the enzyme activity showed that,= a higher activity was found with Ca++ which gave 12.2 viscosity    units. When different concentrations of Ca++ were tested, the maximum activity of the enzyme was found at 50 mg/ ml concentration, which gave 18.0 viscosity units. It could be recommended that the tested bacterium should be investigated for the production of the cellulases and hemi-cellulases which also have a role in the pathogenesis process

Antibacterial Activities of Yansoon (Pimpinella anisum L.), Ginger (Zingiber officinale L.) and Cinnamon (Cinnamomum zeylanicum L.) Extracts

There is an increasing demand for the biologically active substances from plant origin which is of current interest and focus for new research approach. The synthetic pharmaceuticals compounds showed various side effects on functions of different parts of the human body, both internally and externally. Therefore, the present study was investigating the antimicrobial activity of three important herbs, Ginger (Zingiber officinale L.), Yansoon (Pimpinella anisum L.) and Cinnamon (Cinnamomum zeylanicum L.). The cup- plate agar (inhibition zone) method was used for studying the effects of the extracts against Streptococcus sp, Staphylococcus aureus and  Enterococcus faecalis. The results showed that, the ethanol extracts of cinnamon and the combination of ginger and cinnamon were highly effective on Streptococcus sp (24mm and 21mm, respectively), compared to the water extracts (15mm and16mm, respectively). However, the water and the ethanol extracts of ginger and yansoon were less effective (11mm, 9mm, 8.5mm and 8mm, respectively). The ethanol extracts of cinnamon and the combination of ginger and cinnamon were highly effective on Staphylococcus aureus giving (24mm and 21.5 mm, respectively) followed by water extract (20mm and 21 mm, respectively). While, the ethanol and water extracts of ginger and yansoon were less effective (11mm, 10.5mm, 9mm and 9.5mm, respectively). The ethanol and water extracts of cinnamon were highly effective on E. faecalis giving (21mm and 20.5 mm, respectively). The ethanol extracts of the combination of ginger and cinnamon were effective (20 mm) followed by water extract (18mm). The water and ethanol extracts of ginger and yansoon were less effective giving (15 mm, 12 mm, 8 mm and 9 mm, respectively). From the results it could be concluded that, the extracts of (Cinnamon, Yansoon and Ginger) can be used as antimicrobial agents. It could be suggested that the active antimicrobial components need to be verified in any further study and more microorganism are to be tested                                                                                          . &nbsp

Production of Polysaccharides (Xanthan gum) by Xanthomonas campestris pv. Sesame

Many microorganisms and plants were found produce polysaccharides which are widely varying in their composition and structure. The extracellular polysaccharide produced by   Xanthomonas campestris pv. campestris, is chemically analyzed and used industrially. However, only the xanthan gum which was ranking as the best among the ten polysaccharides was used commercially in large amounts. The xanthan gum has numerous applications in food and other industries. The present study was aiming to investigate the capacity of X; campestris pv. sesami for the production of xanthan gum, using culture media containing different carbon sources. The properties of the produced material were investigated (pH, viscosity, and chromatographic analysis using thin layer chromatography).  The results showed that the weight of the product was increasing with time reaching about 9.8g at the tenth day compared to only 2.1g on the second day. The results of the effect of different carbon sources indicated that sucrose was the best giving 9.0 g in the 7th day compared to only 1.5g by raffinose. The pH was changing from 6.7 at the beginning of the experiment to 4.2 in the tenth day. However, the viscosity of the inoculated sucrose medium was found to increase from 2.4 unit at the second day to 9.7 units after ten days. Analysis on paper chromatography showed that the produced polysaccharide contains mannose, glucuronic acid, glucose, rhamnose but no ribose nor trehalose or fructose were detected. The results indicated that the investigated bacterium was producing large amounts of xanthan gum. Although, Xanthan gum was discovered in 1950s its substantial commercial production began in 1964 and in 1969, the USA, Food and Drug Administration authorized its use in food. Xanthan gum, now has numerous uses in food and other industries. Further studies should be carried on other isolates  of the bacterium   X. campestris pv. sesami and more chemical analysis are needed

LC-MS/MS Tandem Mass Spectrometry for Analysis of Phenolic Compounds and Pentacyclic Triterpenes in Antifungal Extracts of Terminalia brownii (Fresen)

Decoctions and macerations of the stem bark and wood of Terminalia brownii Fresen. are used in traditional medicine for fungal infections and as fungicides on field crops and in traditional granaries in Sudan. In addition, T. brownii water extracts are commonly used as sprays for protecting wooden houses and furniture. Therefore, using agar disc diffusion and macrodilution methods, eight extracts of various polarities from the stem wood and bark were screened for their growth-inhibitory effects against filamentous fungi commonly causing fruit, vegetable, grain and wood decay, as well as infections in the immunocompromised host. Ethyl acetate extracts of the stem wood and bark gave the best antifungal activities, with MIC values of 250 ug/mL against Nattrassia mangiferae and Fusarium verticillioides, and 500 ug/mL against Aspergillus niger and Aspergillus flavus. Aqueous extracts gave almost as potent effects as the ethyl acetate extracts against the Aspergillus and Fusarium strains, and were slightly more active than the ethyl acetate extracts against Nattrassia mangiferae. Thin layer chromatography, RP-HPLC-DAD and tandem mass spectrometry (LC-MS/MS), were employed to identify the chemical constituents in the ethyl acetate fractions of the stem bark and wood. The stem bark and wood were found to have a similar qualitative composition of polyphenols and triterpenoids, but differed quantitatively from each other. The stilbene derivatives, cis- (3) and trans- resveratrol-3-O-b-galloylglucoside (4), were identified for the first time in T. brownii. Moreover, methyl-(S)-flavogallonate (5), quercetin-7-b-O-di-glucoside (8), quercetin-7-O-galloyl-glucoside (10), naringenin-40-methoxy-7-pyranoside (7), 5,6-dihydroxy-30,40,7-tri-methoxy flavone (12), gallagic acid dilactone (terminalin) (6), a corilagin derivative (9) and two oleanane type triterpenoids (1) and (2) were characterized. The flavonoids, a corilagin derivative and terminalin, have not been identified before in T. brownii. We reported earlier on the occurrence of methyl-S-flavogallonate and its isomer in the roots of T. brownii, but this is the first report on their occurrence in the stem wood as well. Our results justify the traditional uses of macerations and decoctions of T. brownii stem wood and bark for crop and wood protection and demonstrate that standardized extracts could have uses for the eco-friendly control of plant pathogenic fungi in African agroforestry systems. Likewise, our results justify the traditional uses of these preparations for the treatment of skin infections caused by filamentous fungi.Peer reviewe

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Evaluation of Green Silver Nanoparticles Fabricated by Spirulina platensis Phycocyanin as Anticancer and Antimicrobial Agents

Green nanotechnology has attracted attention worldwide, especially in treating cancer and drug-resistant section 6 microbes. This work aims to investigate the anticancer activity of green silver nanoparticles synthesized by Spirulina platensis phycocyanin (SPAgNPs) on two cancer cell lines: Lung cancer cell line (A-549) and breast cancer cell line (MCF-7), compared to the normal human lung cell line (A138). We also aimed to investigate the bactericidal activity against Staphylococcus aureus ATCC29737, Bacillus cereus ATCC11778, Escherichia coli ATCC8379, and Klebsiella pneumonia, as well as the fungicidal activity against Candida albicans (ATCC6019) and Aspergillus niger. The obtained SPAgNPs were spherical and crystalline with a size of 30 nm and a net charge of &minus;26.32 mV. Furthermore, they were surrounded by active groups responsible for stability. The SPAgNPs scavenged 85% of the DPPH radical with a relative increase of approximately 30% over the extract. The proliferation of cancer cells using the MTT assay clarified that both cancer cells (A-549 and MCF-7) are regularly inhibited as they grow on different concentrations of SPAgNPs. The maximum inhibitory effect of SPAgNPs (50 ppm) reached 90.99 and 89.51% against A-549 and MCF7, respectively. Regarding antimicrobial activity, no inhibition zones occurred in bacterial or fungal strains at low concentrations of SPAgNPs and the aqueous Spirulina platensis extract. However, at high concentrations, inhibition zones, especially SPAgNPs, were more potent for all tested microorganisms than their positive controls, with particular reference to Staphylococcus aureus, since the inhibition zones were 3.2, 3.8, and 4.3 mm, and Bacillus cereus was 2.37 mm when compared to tetracycline (2.33 mm). SPAgNPs have more potent antifungal activity, especially against Aspergillus niger, compared to their positive controls. We concluded that SPAgNPs are powerful agents against oxidative stress and microbial infection