Ökologie, Virulenz und Genomanalyse von Legionella pneumophila Isolaten aus der West Bank, Palästina

Legionella pneumophila is an environmental bacterium and a human pathogen causing life-threating outbreaks of an atypical pneumonia called Legionnaires’ disease. This study aimed to understand the diversity of L. pneumophila isolates, their clonal populations and the environmental driver of their abundance and prevalence in the West Bank. For this, a multi-annual seasonal sampling of nine drinking water sites in the West Bank were performed with a detailed recording of physico-chemical parameters. A total of 180 L. pneumophila isolates were obtained and analysed by high resolution genotyping (Multi-Locus Variable Number of Tandem Repeats (MLVA-8(12)). Also, physiological and virulence traits were studied. Genotyping and the studied traits led to the selection of representative strains submitted to high through-put genome sequencing (Illumina HiSeq and Pacific Biosciences platforms). Analysis of genotype prevalence in correspondence to environmental factors was used to elucidate genotype consortia and their environmental niches. The 180 isolates represented twenty-six individual MLVA-8(12) genotypes (Gt). The most frequently genotype was Gt4(17) (41.1%). All MLVA genotypes were clustered into four MLVA clonal complexes. Analysis of the prevalence of genotype indicated genotype consortia that seemed to be triggered by a set of environmental drivers. The concentration of several ions (Mg, Ca, Cl, SO4 and TDS) and turbidity seemed to determine niches for three different sets of genotypes and may explain their regional variability. Also, the abundance of L. pneumophila was influenced by these environmental drivers with Mg having a negative effect. The virulence of a representative subset of sixty environmental strains was assessed by five different in-vitro assays. Virulence traits were shown to be genotype dependent. A carefully selected subset of thirty-eight L. pneumophila isolates were genome sequenced and compared to already published reference genomes. Genome sequences were aligned with the sequence of the respective reference genome and analysed with respect to core-single nucleotide polymorphisms (core-SNPs), genomic islands and genes related to virulence traits. Overall, this study provided important insights into detailed population structure, the ecology and pathogenicity of this pathogen in the West Bank.Legionella pneumophila ist ein Umweltbakterium in Süsswassersystemen und humanpathogen; es verursacht lebensbedrohliche Ausbrüche der Legionärskrankheit, einer atypischen Pneumonie. Das Ziel der Doktorarbeit ist es, in der West Bank die Diversität von L. pneumophila-Isolaten, ihre clonale Populationsstruktur und die wesentlichen Umweltfaktoren, die Abundanz und Prävalenz steuern, zu verstehen. Hierzu wurde ein mehrjähriges saisonales Probenahmeprogramm für 9 Trinkwasserprobe-nahmestellen repräsentatv für die West Bank durchgeführt, bei dem physico-chemische und mikrobiologische Parameter mitaufgezeichnet wurden. 180 Isolate wurden hierbei gewonnen, hochauflösend genotypisiert (Multi-Locus Variable Number of Tandem Repeats (MLVA-8(12)), und hinsichtlich relevanter physiologischer Eigenschaften und Virulenzfaktoren analysiert. Die umfassende Charakterisierung der Isolate bildete die Grundlage zur Auswahl repräsentativer Stämme für die Genomsequenzierung mittels Illumina HiSeq und der Pac-Biosciences Platform. Die statistische Analyse von regionaler Genotypprävalenz und Umweltfaktoren wurde dazu genutzt um Genotypkonsortien und ihre Umweltnischen zu charakterisieren. Die 180 Isolate aus der Westbank zeigten eine hohe Genotypdiversität von 26 MLVA-8(12)-Genotypen, zugehörig zu vier MLVA clonalen Komplexen. Analysen der Prävalenz von Genotypen im Hinblick auf Umweltfaktoren zeigte, daß Konsortien von Genotypen durch Umweltfaktoren getriggert wurden. Unterschiedliche Konzentrationen von Ionen im Trinkwasser (Mg, Ca, Cl, SO4, TDS) and Trübung schienen Nischen für drei unterschiedliche Konsortien von Genotypen zu bestimmen, und könnten die räumliche Variabilität der Genotypen in der West Bank erklären und die Abundanz von L. pneumophila zu beeinflussen. Dabei schien Mg eine relevante Rolle zu spielen. Die Virulenz einer repräsentativen Untergruppe von 60 Isolaten wurde mit 5 in-vitro Ansätzen getestet. Die Virulenzstärke variierte in Abhängigkeit vom Genotyp mit relativ hoher Virulenz der häufigen Genotypen Gt4(17) und Gt6(18). Eine repräsentative Auswahl von 38 L. pneumophila Isolaten wurden genomsequenziert und mit Referenzgenomen und generierten eigenen Referenzgenomen verglichen, und hinsichtlich core-SNPs, genomischen Inseln und Virulenz-assoziierten Genen analysiert. Insgesamt gesehen, liefert die vorliegende Studie wichtige Einblicke zum Verständnis von Populationsstruktur, Ökologie und Pathogenität dieses pathogenen Bakteriums in der West Bank

Synthesis and Characterization of Zno Nanoparticles Using Hydrothermal and Sol-Gel Techniques for Dye-Sensitized Solar Cells

في هذا البحث تم تخليق جسيمات نانوية نقية من أكسيد الزنك باستخدام طريقتي الهيدروثيرمال وطريقة الصول جل. من فحوصات حيود الاشعة السينية تبين أن متوسط حجم الحبيبة تتراوح بين من 25 الي 28 نانومتر وتاخذ شكلا كرويا. فحوصات طيف الامتصاص بينت أن العينات جميعها لها اعلي امتصاص في منطقة الاشعة الفوق بنفسجية. وتم حساب فجوة الطاقة للعينات فوجد انها تساوي 3.13 eV و3.16 eV للعينة التي حضرت بطريقة الهيدروثيرمال والصول جل على الترتيب. تم تحضير عينات لخلايا شمسية صبغية وتم استخدام 3 انواع من الاصباغ الكيمياءية كمتحسسات ضوئية. فحوصات الاشعة الفوق بنفسجية بينت ان صبغة الايوزين الاصفر   Eosin Yتعطي اعلي امتصاص مقارنة بالاصباغ المستخدمة الاخري. تم رسم منحني الخواص لجميع العينات للخلايا الشمسية المحضرة وتم حساب جميع البارامترات اللازمة لتقييم اداء الخلية. العينة المصبوغة بصبغةEosin Y اعطت اعلي كفاءة Jsc = 4.25 (mA/cm2)، Voc = 0.51 V and η=1.08 %ZnO nanoparticles (ZnO NPs) were synthesized using hydrothermal and sol-gel techniques using zinc acetate dihydrate (Zn (CH3COO)2.2H2O) as a row material and methanol as a solvent. The structural properties of ZnO NPs were studied using EDX, XRD, TEM, and the optical properties were characterized using UV-VIS and PL spectroscopies. The synthesized ZnO NPs showed high purity and revealed a wurtzite (hexagonal) crystal structure with particle size (D) ranged from 25 nm to 28 nm. The UV-VIS absorption spectra of ZnO NPs samples and sensitizing dyes were performed. The obtained ZnO NPs exhibited the direct optical bandgap 3.15 eV. Dye-sensitized solar cells (DSSCs) were fabricated using synthesized ZnO NPs as a semiconducting layer, which was dyed with different low cost dyes such as Eosin B (EB), Eosin Y (EY) and Rhodamine B (RB) that was used to sensitize the photoanode (ZnO NPs). The experimental results showed a significant efficiency for the fabricated DSSCs of synthesized ZnO NPs via sol gel technique comparing to hydrothermal technique. The EY dye exhibited the best performance among others, where a conversion efficiency showed a noteworthy improvement from 0.12 to 1.08 %

Compromised BRCA1-PALB2 interaction is associated with breast cancer risk.

The major breast cancer suppressor proteins BRCA1 and BRCA2 play essential roles in homologous recombination (HR)-mediated DNA repair, which is thought to be critical for tumor suppression. The two BRCA proteins are linked by a third tumor suppressor, PALB2, in the HR pathway. While truncating mutations in these genes are generally pathogenic, interpretation of missense variants remains a challenge. To date, patient-derived missense variants that disrupt PALB2 binding have been identified in BRCA1 and BRCA2; however, there has not been sufficient evidence to prove their pathogenicity in humans, and no variants in PALB2 that disrupt either its BRCA1 or BRCA2 binding have been reported. Here we report on the identification of a novel PALB2 variant, c.104T>C (p.L35P), that segregates in a family with a strong history of breast cancer. Functional analyses showed that L35P abrogates the PALB2-BRCA1 interaction and completely disables its abilities to promote HR and confer resistance to platinum salts and PARP inhibitors. Whole-exome sequencing of a breast cancer from a c.104T>C carrier revealed a second, somatic, truncating mutation affecting PALB2, and the tumor displays hallmark genomic features of tumors with BRCA mutations and HR defects, cementing the pathogenicity of L35P. Parallel analyses of other germline variants in the PALB2 N-terminal BRCA1-binding domain identified multiple variants that affect HR function to varying degrees, suggesting their possible contribution to cancer development. Our findings establish L35P as the first pathogenic missense mutation in PALB2 and directly demonstrate the requirement of the PALB2-BRCA1 interaction for breast cancer suppression

Management of SARS-CoV-2 Infection: Key Focus in Macrolides Efficacy for COVID-19

Macrolides (e.g., erythromycin, fidaxomicin, clarithromycin, and azithromycin) are a class of bacteriostatic antibiotics commonly employed in medicine against various gram-positive and atypical bacterial species mostly related to respiratory tract infections, besides they possess anti-inflammatory and immunomodulatory effects. Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome of coronavirus 2 (SARS-CoV-2). It was first detected in Wuhan, Hubei, China, in December 2019 and resulted in a continuing pandemic. Macrolides have been extensively researched as broad adjunctive therapy for COVID-19 due to its immunostimulant abilities. Among such class of drugs, azithromycin is described as azalide and is well-known for its ability to decrease the production of pro-inflammatory cytokines, including matrix metalloproteinases, tumor necrosis factor-alpha, interleukin (IL)-6, and IL-8. In fact, a report recently published highlighted the effectiveness of combining azithromycin and hydroxychloroquine for COVID-19 treatment. Indeed, it has been underlined that azithromycin quickly prevents SARS-CoV-2 infection by raising the levels of both interferons and interferon-stimulated proteins at the same time which reduces the virus replication and release. In this sense, the current review aims to evaluate the applications of macrolides for the treatment of COVID-19.NC-M acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017)