Nova strategija za postizanje visoke antimikrobne djelotvornosti: zelena sinteza formulacija srebrnih nanočestica pomoću biljnih vrsta Galium aparine i Helichrysum arenarium

Silver nanoparticles (AgNPs), which have recently gained attention due to their antimicrobial activity, can also be produced by green synthesis. The aims of this study were to (i) characterise green synthesized AgNPs using microwave-assisted aqueous extracts of Galium aparine (G-AgNPs) and Helichrysum arenarium (H-AgNPs) and (ii) investigate the combined antimicrobial effects of the G- and H-AgNPs in different ratios. Nanoparticle formation and reactions were determined with UV-Vis spectroscopy. The G-AgNPs were 52.0±10.9 nm in size, with a 0.285±0.034 polydispersity index (PDI), and a -17.9±0.9 mV zeta potential. For H-AgNPs these characteristics were 23.9±1.0 nm, 0.280±0.032, and -21.3±2.7 mV, respectively. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the particles were monodisperse and spherical. The Fourier transform-infrared spectroscopy (FT-IR) results showed the presence of reducing agents that stabilised the AgNPs. Three different nanoformulations (NF-1, NF-2, and NF-3) were prepared by combining these two synthesised nanoparticles in different ratios and their antimicrobial activity was tested against E. coli, S. aureus, C. albicans, and A. flavus. Our study is the first to show that combining AgNPs from two different biological sources can produce effective nanoformulations with improved antibacterial activity against E. coli and S. aureus. These nanoformulations showed lower minimum inhibitory concentrations (31.25 μg/mL against E. coli with all NFs; 62.5 μg/mL for NF-1 and 125 μg/mL for NF-2/3 against S. aureus) than G-AgNPs (62.5 μg/mL for E. coli) or H-AgNPs (125 μg/mL for S. aureus) alone. Their high combined inhibitory effect against E. coli (NF-1–3) was synergistic and against S. aureus (NF-2 and NF-3) potentially additive. Considering such promising results, we believe our study provides some direction for new research and strategies in antimicrobial therapeutics.Srebrne se nanočestice (AgNP), koje su već neko vrijeme u središtu pažnje zbog svojih antimikrobnih svojstava, mogu proizvoditi i zelenom sintezom. Cilj je ovog istraživanja bio (i) opisati (karakterizirati) zelenu sintezu različitih AgNP-a pomoću vodenih ekstrakata čekinjaste broćike (Galium aparine) (G-AgNPs) i pješčarskoga smilja (Helichrysum arenarium) (H-AgNPs), dobivenih metodom mikrovalne ekstrakcije, te (ii) utvrditi antimikrobno djelovanje kombinacije tih dvaju nanosustava u različitim omjerima. Oblikovanje nanočestica i kemijske reakcije utvrđene su pomoću UV-Vis spektroskopije. Veličina G-AgNP-a bila je 52,0±10,9 nm, njihov polidisperzivni indeks (PDI) 0,285±0,034, a zeta potencijal -17,9±0,9 mV. Osobine H-AgNP-a bile su sljedeće: veličina 23,9±1,0 nm, PDI 0,280±0,032, a zeta potencijal -21,3±2,7 mV. Mikroskopijom atomskih sila (engl. atomic force microscopy, krat. AFM) i pretražnom elektronskom mikroskopijom (engl. scanning electron microscopy, krat. SEM) potvrđeno je da su čestice monodisperzivne i sferične. Rezultati infracrvene spektroskopije s Fourierovom transformacijom (engl. Fourier transform-infrared spectroscopy, krat. FT-IR) potvrdili su prisutnost reduktivnih agenasa koji su stabilizirali srebrne nanočestice. Zatim su pripremljene tri formulacije nanočestica (NF-1, NF-2 i NF-3) kombinacijom sintetiziranih nanočestica u različitim omjerima, a njihova antimikrobna djelotvornost testirana je na mikroorganizmima E. coli, S. aureus, C. albicans i A. flavus. Naše je istraživanje prvo koje dokazuje da kombinacija srebrnih nanočestica dobivenih iz dvaju bioloških izvora može biti djelotvorna te da ima poboljšano antibakterijsko djelovanje protiv E. coli i S. aureus u odnosu na zasebne nanosustave. Minimalna inhibicijska koncentracija kombinacija iznosila je 31,25 μg/mL za E. coli u svim nanoformulacijama te 62,5 μg/mL za S. aureus s NF-1, odnosno 125 μg/mL s NF-2 i NF-3, a minimalne inhibicijske koncentracije G-AgNP-a odnosno H-AgNP-a zasebno su iznosile 62,5 μg/mL za E. coli (G-AgNP), odnosno 125 μg/mL za S. aureus (H-AgNP). To kombinirano antibakterijsko djelovanje protiv E. coli bilo je sinergijsko, a protiv S. aureus naizgled aditivno. S obzirom na ovako obećavajuće rezultate, smatramo da naše istraživanje daje smjer za razvoj novih strategija u antibakterijskom liječenju

Treatment of ventilator-associated pneumonia (VAP) caused by Acinetobacter: results of prospective and multicenter ID-IRI study

Ventilator-associated pneumonia (VAP) due to Acinetobacter spp. is one of the most common infections in the intensive care unit. Hence, we performed this prospective-observational multicenter study, and described the course and outcome of the disease. This study was performed in 24 centers between January 06, 2014, and December 02, 2016. The patients were evaluated at time of pneumonia diagnosis, when culture results were available, and at 72 h, at the 7th day, and finally at the 28th day of follow-up. Patients with coexistent infections were excluded and only those with a first VAP episode were enrolled. Logistic regression analysis was performed. A total of 177 patients were included; empiric antimicrobial therapy was appropriate (when the patient received at least one antibiotic that the infecting strain was ultimately shown to be susceptible) in only 69 (39%) patients. During the 28-day period, antibiotics were modified for side effects in 27 (15.2%) patients and renal dose adjustment was made in 38 (21.5%). Ultimately, 89 (50.3%) patients died. Predictors of mortality were creatinine level (OR, 1.84 (95% CI 1.279-2.657); p = 0.001), fever (OR, 0.663 (95% CI 0.454-0.967); p = 0.033), malignancy (OR, 7.095 (95% CI 2.142-23.500); p = 0.001), congestive heart failure (OR, 2.341 (95% CI 1.046-5.239); p = 0.038), appropriate empiric antimicrobial treatment (OR, 0.445 (95% CI 0.216-0.914); p = 0.027), and surgery in the last month (OR, 0.137 (95% CI 0.037-0.499); p = 0.003). Appropriate empiric antimicrobial treatment in VAP due to Acinetobacter spp. was associated with survival while renal injury and comorbid conditions increased mortality. Hence, early diagnosis and appropriate antibiotic therapy remain crucial to improve outcomes

A new strategy to achieve high antimicrobial activity: green synthesised silver nanoparticle formulations with Galium aparine and Helichrysum arenarium

Silver nanoparticles (AgNPs), which have recently gained attention due to their antimicrobial activity, can also be produced by green synthesis. The aims of this study were to (i) characterise green synthesized AgNPs using microwave-assisted aqueous extracts of Galium aparine (G-AgNPs) and Helichrysum arenarium (H-AgNPs) and (ii) investigate the combined antimicrobial effects of the G- and H-AgNPs in different ratios. Nanoparticle formation and reactions were determined with UV-Vis spectroscopy. The G-AgNPs were 52.0±10.9 nm in size, with a 0.285±0.034 polydispersity index (PDI), and a -17.9±0.9 mV zeta potential. For H-AgNPs these characteristics were 23.9±1.0 nm, 0.280±0.032, and -21.3±2.7 mV, respectively. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the particles were monodisperse and spherical. The Fourier transform-infrared spectroscopy (FT-IR) results showed the presence of reducing agents that stabilised the AgNPs. Three different nanoformulations (NF-1, NF-2, and NF-3) were prepared by combining these two synthesised nanoparticles in different ratios and their antimicrobial activity was tested against E. coli, S. aureus, C. albicans, and A. flavus. Our study is the first to show that combining AgNPs from two different biological sources can produce effective nanoformulations with improved antibacterial activity against E. coli and S. aureus. These nanoformulations showed lower minimum inhibitory concentrations (31.25 µg/mL against E. coli with all NFs; 62.5 µg/mL for NF-1 and 125 µg/mL for NF-2/3 against S. aureus) than G-AgNPs (62.5 µg/mL for E. coli) or H-AgNPs (125 µg/mL for S. aureus) alone. Their high combined inhibitory effect against E. coli (NF-1–3) was synergistic and against S. aureus (NF-2 and NF-3) potentially additive. Considering such promising results, we believe our study provides some direction for new research and strategies in antimicrobial therapeutics

Angio-oedema as an unusual tolerable side effect of voriconazole therapy.

Voriconazole (VRC) has not previously been reported to cause angio-oedema. Here, we report a case of angio-oedema associated with VRC therapy. A 37-year-old woman with relapsing invasive vertebral aspergillosis received intravenous VRC and developed angio-oedema 10 days after starting therapy. This condition rapidly diminished after administration of intravenous antihistaminics and did not necessitate cessation of VRC treatment. The treatment was continued for 6 months without recurrence of the symptoms. After 18 months, the patient was in good health. To our knowledge, this is the first report of an angio-oedema associated with VRC

A Retrospective Case-Control Study, Factors Affecting Treatment Outcomes for Pulmonary Tuberculosis in Istanbul, Turkey

Background: Tuberculosis is a public health problem and its transmission is a threat to the community

In vitro activities of colistin combined with imipenem, tigecycline or cefoperazone-sulbactam against multidrug-resistant Acinetobacter baumannii blood-stream isolates

Acinetobacter baumannii has emerged as one of the most important nosocomial pathogens and multi-drug resistant (MDR) isolates are of great concern worldwide. The aim of the present study was to investigate the in vitro synergistic activity of colistin in combination with other antibiotics against MDR A. baumannii blood stream isolates. A total of 54 non-duplicate, MDR A. baumannii isolates from blood culture specimens obtained between June 2011 and July 2012 were included in the study. In vitro synergistic activity of colistin in combination with imipenem, tigecycline or cefoperazone-sulbactam against study isolates was investigated by Etest superimposing method and the fractional inhibitory concentration (FIC) index was calculated for each antibiotic combination. The most frequent synergistic effect of colistin was found in combination with tigecycline in only 7 isolates (13.0%). All three antibiotics were found to have synergistic effect with colistin in four isolates (7.4%). Of isolates, 46 (85.2%) showed additive effect of colistin in combination with cefoperazone-sulbactam or tigecycline, 45 (83.3%) with imipenem. We found synergistic activity of colistin with other study antibiotics in only a small number of isolates. Although Etest method is a practical method to investigate the synergistic activity, in case of choosing empirical treatment, colistin in combination with another antibiotic may be preferred. [Dis Mol Med 2016; 4(4.000): 51-54

J. GroupTheory6 (2003),223-228 Journal of GroupTheory cgdeGruyter2003

(CommunicatedbyI. B. S.Passi) Abstract.LetA beanabeliannormalsubgroupof afinitegroupG.Thenallunitsof theinte-gralgroupring7lGwhichareof theform1+J with0 ""J Ed(G)d(A), whered denotesthe augmentationideal,areof infiniteorder