Antimicrobial

摘要： In light of the rising evidence of the association between viral and bacterial infections and neurodegeneration,we aimed at revisiting the infectious hypothesis of Alzheimer’s disease and analyzing the possible implications of COVID-19 neurological sequelae in long-term neurodegeneration.We wondered how SARS-CoV-2 could be related to the amyloid-βcascade and how it could lead to the pathological hallmarks of the disease.We also predict a paradigm change in clinical medicine,which now has a great opportunity to conduct prospective surveillance of cognitive sequelae and progression to dementia in people who suffered severe infections together with other risk factors for Alzheimer’s disease.

摘要： BACKGROUND Helicobacter pylori(H.pylori)causes chronic gastritis,peptic ulcer disease,gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma.Eradication rates have fallen,mainly due to antimicrobial resistance.Consensus guidelines recommend that first-line treatment is based on the local prevalence of antimicrobial resistance and that rescue therapies are guided by antimicrobial susceptibility testing(AST).However,H.pylori culture is challenging and culture-based AST is not routinely performed in the majority of hospitals.Optimisation of H.pylori culture from clinical specimens will enable more widespread AST to determine the most appropriate antimicrobials for H.pylori eradication.AIM To determine whether dual antrum and corpus biopsy sampling is superior to single antrum biopsy sampling for H.pylori culture.METHODS The study received ethical approval from the joint research ethics committee of Tallaght University Hospital and St.James’s Hospital.Patients referred for upper gastrointestinal endoscopy were invited to participate.Biopsies were collected in tubes containing Dent’s transport medium and patient demographics were recorded.Biopsies were used to inoculate Colombia blood agar plates.Plates were incubated under microaerobic conditions and evaluated for the presence of H.pylori.Statistical analyses were performed using Graphpad PRISM.Continuous variables were compared using the two-tailed independent t-test.Categorical variables were compared using the two-tailed Fisher exact test.In all cases,a P value less than 0.05 was considered significant.RESULTS In all,samples from 219 H.pylori-infected patients were analysed in the study.The mean age of recruited patients was 48±14.9 years and 50.7%(n=111)were male.The most common endoscopic finding was gastritis(58.9%;n=129).Gastric ulcer was diagnosed in 4.6%(n=10)of patients,while duodenal ulcer was diagnosed in 2.7%(n=6).Single antrum biopsies were collected from 73 patients,whereas combined antrum and corpus biopsies were collected from 146 patients.There was no significant difference in age,sex or endoscopic findings between the two groups.H.pylori was successfully cultured in a significantly higher number of cases when combined antrum and corpus biopsies were used compared to a single antrum biopsy[64.4%(n=94/146)vs 49.3%(36/73);P=0.04)].CONCLUSION Combined corpus and antrum biopsy sampling improves H.pylori culture success compared to single antrum biopsy sampling.

摘要： Prodigiosin is a red pigment with a pyrrolylpyrromethane skeleton.It is mainly produced by bacterial strains belonging to the Serratia genus,but also by some other genera,including Streptomyces and Vibrio.Within the genus Serratia,the pigment is generally produced as a virulence factor.However,it also has many important beneficial biological activities such as immunosuppressive and anti-proliferative activities.Moreover,the pigment has many industrial applications in textile and cosmetics.In this mini-review,we discuss the genetic and molecular mechanisms supporting prodigiosin synthesis and production from the Serratia genus,as well as its potential applications.

摘要： Marine microorganisms were considered to be important sources of marine bioactive compounds.The major objective of the study was to isolate and characterize bacteria with antimicrobial activities from the various marine environment of Egypt.In this respect,thirty-five bacterial isolates were recovered from sediment samples collected from different spots along the Egyptian Red Sea coastline and Alexandria coastline during the summer season of 2017 and 2018.According to the morphological,physiological,and biochemical characteristics,the bacterial isolates were clustered into 13 groups designated as A,B,…,M.And,14 Gram-negative and 21 Grampositive bacteria were determined.The isolated bacterial strains were screened for their potentiality for antimicrobial agent(s)production against ten indicator strains.Strain Mo13 was showed high antimicrobial activity against all empirical strains.Subsequently,the most promising marine bacterial isolate with code MO13 was identified as Bacillus zhangzhouensis OMER4 according to the phenotypic characterization through morphological,physiological,and biochemical tests as well as genotypic characterization through the 16 S rDNA technique.The bioactive components were extracted with ethyl acetate,then analyzed using GC-MS and the substantial component was recognized as phenol,2,4-bis(1,1-dimethyl ethyl).

摘要： Microalgae are unicellular photosynthetic microorganisms that are commonly found in saline or freshwater environments.Over the years,microalgae represent promising sources of sustainable bioactivities with past literatures reflecting a growing interest in algae-based dietary supplements in the form of whole biomass.Notably,the bioactive molecules that can be identified and extracted in microalgae have scientifically proven to contain therapeutic properties which can be beneficial to human health.With the increasing occurrence of global health threats such as antimicrobial resistance and cancer,this has resulted in considerable attention for microalgae study especially in the medicinal field.Although studies have proved the therapeutic potentials of high-value bioproducts in microalgae,however,there is still room to understand their potential therapeutic properties on humans’health,discovering novel microalgae-derived bioactive compounds,as well as translating the lab-based evidence to clinical trial studies.This review will focus on accessing the biochemical compositions of commercialised microalgae species from 2007 to 2020,and the activity of their biologically active molecules in eliciting selected therapeutic potentials which are anti-oxidative,anti-inflammatory,anti-microbial and anti-cancer properties.This review article will also be looking at the research gaps in addition to the above four major selected therapeutic potentials,and future prospective.

摘要： Owing to the ongoing pandemic,the importance of and demand for antimicrobial textiles have reached new heights.In addition to being used for medical purposes,antimicrobial textiles could be a self-defense entity against microbes for the general population.Because textiles are widely used,they can effectively be used to prevent the spread of microbes worldwide.The conventional antibacterial finishing process of textiles is the wet treatment method using either the pad–dry–cure or exhaustion techniques.However,the textile wet treatment industries are major contributors to worldwide pollution,which is extremely concerning.Given the current and near-future high demand,it is imperative to include plasma in antimi-crobial finishing to achieve high efficiency in production,while retaining a safe environment.Hence,this paper reviews the rationale of plasma use in textile antimicrobial finishing through a critical analysis of recent studies and emphasizes the types and mechanisms of plasma techniques available for application.

摘要： Extracts of two edible mushrooms, Pleurotus sajor-caju (commercial) and Schizophyllum commune (wild) were used to compare the antioxidant and antimicrobial properties. Aqueous and three types of organic solvents, like 50% of ethanol, methanol and acetone extracts were used in trial. DPPH scavenging activity in P. sajor-caju extract was determined in the range of 53.13% to 85.08%, whereas extracts of S. commune were observed in the range of 54.11% to 97.19% at a concentration of 5 mg/ml. The highest DPPH scavenging activity of 97.19% was observed in ethanol extract of S. commune (97.19%), higher than butyl hydroxytoluene (BTH). Half effective concentration (EC50) in extracts of P. sajor-caju was found in the range of 1.47 to 4.23 mg/ml and that of S. commune in the range of 1.52 to 4.52 mg/ml. The reducing power of P. sajor caju aqueous concentration extract was found to be the closest of 3.353 (700 nm) that of antioxidant activity to BHT (3.445) at 2 mg/ml concentration. The best reducing power EC50 was obtained in P. sajor caju aqueous extract (0.09 mg/ml), but in S. commune with acetone extract (0.22 mg/ml). Minimum inhibition concentration (MIC) was compared in extracts of mushrooms in various Vibrio species. All extracts were able to inhibit V. harveyi growth with MIC of lower than 1.25 mg/ml. In aqueous and methanol extracts of current study showed that bacteria inhibition activity occurred at the concentration of P. sajor-caju was able to act as reducing agent as functional as the commercial antioxidant agent, BHT. Crude extracts of P. sajor-caju and S. commune were observed to contain antibacterial potential against these mentioned Vibrio bacteria.

摘要： Microbial infections cause complicated health influences along with bad economic impacts.In the present investigation,three dominant seaweeds namely,Amphiroa anceps,Corallina officinalis and Sargassum filipendula were collected from different Egyptian sites at the Red Sea and Mediterranean Sea during autumn 2019.Organic extracts of the three algae were screened for their antibacterial activity against three pathogenic bacteria Salmonella typhiimurium,Staphylococcus aureus and Escherichia coli,in addition to in vitro antiviral activity against Rotavirus(RV),and Coxsackie virus B3(CVB3)that cause severe diseases in human.Organic extract of A.anceps,C.officinalis and S.filipendula inhibit E.coli cells by 57.1%,85.7%,and 91.4%,respectively.The highest level of concentration of the C.officinalis extract(100μg/mL)inhibits 100%of Staphylococcus aureus cells followed by S.filipendula and A.anceps extract which inhibit 82.5%and 75%of S.aureus.Similarly,the highest concentration of C.officinalis extract inhibits S.typhiimurium by 80%.The extract of A.anceps exhibited a high antiviral effect against RV infection with TI=22 and virus titers lessened by 2.75 log TCID_(50) followed by extractions of C.officinalis with TI=18.3 and virus titers reduced by 2.5 log TCID_(50).Against CVB3 infection,the extract of A.anceps causes the highest antiviral activity with TI=15 and reduce the viral titers by 2.5 log TCID_(50),followed by extractions of C.officinalis with TI=8.8 and inhibition of virus titers by 1.75 log TCID_(50).Extract of S.filipendula displayed the lowest antiviral effects against RV and CVB3 infection with TI=2.4 and 1.4,respectively.The obtained results clarified that the extract of three marine seaweeds maintains a potent antimicrobial activity,making them a future promising source of new antimicrobial drugs.

摘要： Baking of sourdough is a common practice and has the advantage of improving the nutritional value, sensory qualities and increasing the shelf life of the bread. This study therefore focus on the antimicrobial and antioxidant capacity of exopolysaccharides form Lactic Acid Bacteria (LAB) and its application in sourdough production. The Lactobacillus delbrueckii LDYG2 and Weissella confusa WCFF1 were collected from the culture collection Centre and the LABs were maintained in De Man, Rogosa and Sharpe (MRS) broth. Modified Exopolysaccharide Selection Medium (mESM) was used to produce the EPS while the total sugar concentration was determined using phenol-sulfuric acid method. The antibacterial, antioxidant, proximate, physical, organoleptic properties and the shelf life of the SDB produced were also evaluated. The quantity of EPS produced by LDYG2 and WCFF1 ranged from 4743.75 - 5090.03 g/L. Eight different sugars were present in both EPSLD and EPSWC with high antibacterial activity (24 mm and 23 mm) against B. cereus and S. aureus respectively. EPSLD and EPSWC had antioxidant capacity increased in a dose dependent (0.5 - 10 mg/mL) manner. EPSWCSDB had the highest proximate content except for moisture content. There was a significantly different (P ≤ 0.05) in the shelf life extension of the sourdough bread. WCEPSSDB was generally accepted in terms of colour, aroma, taste, texture and palatability. EPS produced by L. delbrueckii (EPSLD) and W. confusa (EPSWC) has antimicrobial and antioxidant capacity and can be used in production of nutraceutical sourdough bread with an improved shelf life and high consumer acceptability.

摘要： Objective:To determine the inhibition mechanisms of secretome protein extracted from Paenibacillus polymyxa Kp10(Kp10)and Lactococcus lactis Gh1(Gh1)against methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Enterococcus(VRE).Methods:The sensitivity and viability of MRSA and VRE treated with secretome proteins of Kp10 and Gh1 were determined using minimal inhibitory concentration,minimum bactericidal concentration,and time-to-kill assays.The morphological changes were observed using scanning electron microscopy and transmission electron microscopy.To elucidate the antimicrobial mechanism of secretome protein of Kp10 and Gh1 against MRSA and VRE,2D gel proteomic analysis using liquid chromatography-mass spectrometry was run by comparing upregulated and downregulated proteins,and the proton motive force study including the efflux of ATP,pH gradient,and the membrane potential study were conducted.Results:MRSA and VRE were sensitive to Kp10 and Gh1 secretome protein extracts and displayed apparent morphological and internal composition changes.Several proteins associated with cellular component functions were either downregulated or upregulated in treated MRSA and VRE by changing the membrane potential gradient.Conclusions:Kp10 and Gh1 secretome proteins reduce the growth of VRE and MRSA by damaging the cell membrane.Cell division,cell wall biosynthesis,and protein synthesis are involved in the inhibition mechanism.

摘要： As the 19th century drew to a close, the work of Joseph Lister ushered in the dawn of the antimicrobialera. Lister was among the first scientists to understand that microorganisms might be involved in human disease. Lister studied the inhibitory effect of various chemicals on the growth and viability of bacteria and directly applied this knowledge to medicine by using phenol to sterilize surgical instruments. Following this early example of infection control, the next step was to use such chemicals to attack microbes causing infection. As the use of antimicrobial agents over the 20th century progressed, their clinical successes were truly amazing and resulted in these agents being hailed as miracle drugs. During the second half of the 20th century, medicine enjoyed almost complete control over bacterial infection.