Impact of Silver Incorporation and Flash-Lamp-Annealing on the Photocatalytic Response of Sputtered ZnO Films.

Thin films of silver-doped zinc oxide (SZO) were deposited at room temperature using a DC reactive magnetron co-sputtering technique using two independent Zn and Ag targets. The crystallographic structure, chemical composition and surface morphology of SZO films with different silver concentrations were correlated with the photocatalytic (PC) properties. The crystallization of the SZO films was made using millisecond range flash-lamp-annealing (FLA) treatments.

A convergent evolutionary pathway attenuating cellulose production drives enhanced virulence of some bacteria.

Bacteria adapt to selective pressure in their immediate environment in multiple ways. One mechanism involves the acquisition of independent mutations that disable or modify a key pathway, providing a signature of adaptation via convergent evolution. Extra-intestinal pathogenic Escherichia coli (ExPEC) belonging to sequence type 95 (ST95) represent a global clone frequently associated with severe human infections including acute pyelonephritis, sepsis, and neonatal meningitis.

Surface Morphology and Optical Properties of Hafnium Oxide Thin Films Produced by Magnetron Sputtering.

Hafnium oxide films were deposited on sapphire and silicon (100) substrates using the DC reactive magnetron sputtering technique from a pure hafnium target at different discharge power levels. The influence of the cathode power on the chemical composition, morphology, crystallographic structure and optical properties of the films was investigated. X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and Fourier-transform infrared spectroscopy (FTIR) were employed to determine the chemical composition and bonding structure.

Antimicrobial Activity of Cefiderocol against the Carbapenemase-Producing Enterobacter cloacae Complex and Characterization of Reduced Susceptibility Associated with Metallo-β-Lactamase VIM-1.

Emergence of cefiderocol resistance among carbapenemase-producing Enterobacterales, particularly those in the Enterobacter cloacae complex (ECC), is becoming of alarming concern; however, the mechanistic basis of this phenomenon remains poorly understood. We describe the acquisition of VIM-1-mediated reduced cefiderocol susceptibility (MICs 0.5 to 4 mg/L) in a collection of 54 carbapenemase-producing isolates belonging to the ECC.

Integrative omics identifies conserved and pathogen-specific responses of sepsis-causing bacteria.

Even in the setting of optimal resuscitation in high-income countries severe sepsis and septic shock have a mortality of 20-40%, with antibiotic resistance dramatically increasing this mortality risk. To develop a reference dataset enabling the identification of common bacterial targets for therapeutic intervention, we applied a standardized genomic, transcriptomic, proteomic and metabolomic technological framework to multiple clinical isolates of four sepsis-causing pathogens: Escherichia coli, Klebsiella pneumoniae species complex, Staphylococcus aureus and Streptococcus pyogenes. Exposure to human serum generated a sepsis molecular signature containing global increases in fatty acid and lipid biosynthesis and metabolism, consistent with cell envelope remodelling and nutrient adaptation for osmoprotection.

Activity of aztreonam in combination with novel β-lactamase inhibitors against metallo-β-lactamase-producing Enterobacterales from Spain.

Metallo-β-lactamase (MBL)-producing Enterobacterales are of particular concern because they are widely disseminated and difficult to treat, being resistant to almost all β-lactam antibiotics. Aztreonam is not hydrolysed by MBLs but is labile to serine β-lactamases (SBLs), which are usually co-produced by MBL-producing Enterobacterales. This study investigated the activity of aztreonam in combination with novel β-lactamase inhibitors (BLIs) against a national multi-centre study collection of strains co-producing MBLs and SBLs.

Differential Afa/Dr Fimbriae Expression in the Multidrug-Resistant Escherichia coli ST131 Clone.

Many antibiotic resistant uropathogenic Escherichia coli (UPEC) strains belong to clones defined by their multilocus sequence type (ST), with ST131 being the most dominant. Although we have a good understanding of resistance development to fluoroquinolones and third-generation cephalosporins by ST131, our understanding of the virulence repertoire that has contributed to its global dissemination is limited. Here we show that the genes encoding Afa/Dr fimbriae, a group of adhesins strongly associated with UPEC that cause gestational pyelonephritis and recurrent cystitis, are found in approximately one third of all ST131 strains.

Plasmid-Mediated Ciprofloxacin Resistance Imparts a Selective Advantage on Escherichia coli ST131.

Escherichia coli ST131 is a recently emerged antibiotic resistant clone responsible for high rates of urinary tract and bloodstream infections. Despite its global dominance, the precise mechanisms that have driven the rapid dissemination of ST131 remain unknown. Here, we show that the plasmid-associated resistance gene encoding the AAC(6')-Ib-cr enzyme that inactivates the fluoroquinolone (FQ) antibiotic ciprofloxacin is present in >70% of strains from the most rapidly expanding subgroup of multidrug resistant ST131.

In-Depth Analysis of the Role of the Acinetobactin Cluster in the Virulence of .

is a multidrug-resistant pathogen that represents a serious threat to global health. possesses a wide range of virulence factors that contribute to the bacterial pathogenicity. Among them, the siderophore acinetobactin is one of the most important, being essential for the development of the infection.

Activity of imipenem/relebactam against a Spanish nationwide collection of carbapenemase-producing Enterobacterales.

Background: Imipenem/relebactam is a novel carbapenem/β-lactamase inhibitor combination, developed to act against carbapenemase-producing Enterobacterales (CPE).

Objectives: To assess the in vitro activity of imipenem/relebactam against a Spanish nationwide collection of CPE by testing the susceptibility of these isolates to 16 widely used antimicrobials and to determine the underlying β-lactam resistance mechanisms involved and the molecular epidemiology of carbapenemases in Spain.

Materials And Methods: Clinical CPE isolates (n = 401) collected for 2 months from 24 hospitals in Spain were tested.

Global Transcriptomic Analysis During Murine Pneumonia Infection Reveals New Virulence Factors in Acinetobacter baumannii.

Background: Infections caused by multidrug-resistant pathogens such as Acinetobacter baumannii constitute a major health problem worldwide. In this study we present a global in vivo transcriptomic analysis of A. baumannii isolated from the lungs of mice with pneumonia infection.

Syzygium aromaticum (clove) and Thymus zygis (thyme) essential oils increase susceptibility to colistin in the nosocomial pathogens Acinetobacter baumannii and Klebsiella pneumoniae.

The discovery of new antibiotics that are effective against Acinetobacter baumannii and Enterobacteralesis a research priority. Several essential oils (EOs) have displayed some antimicrobial activity and could potentially act as antibiotic adjuvants. Research in this area aims to develop new therapeutic alternatives to treat infections caused by these pathogens.

Kpi, a chaperone-usher pili system associated with the worldwide-disseminated high-risk clone ST-15.

Control of infections caused by carbapenem-resistant continues to be challenging. The success of this pathogen is favored by its ability to acquire antimicrobial resistance and to spread and persist in both the environment and in humans. The emergence of clinically important clones, such as sequence types 11, 15, 101, and 258, has been reported worldwide.

Antisense inhibition of lpxB gene expression in Acinetobacter baumannii by peptide-PNA conjugates and synergy with colistin.

Background: LpxB is an enzyme involved in the biosynthesis pathway of lipid A, a component of LPS.

Objectives: To evaluate the lpxB gene in Acinetobacter baumannii as a potential therapeutic target and to propose antisense agents such as peptide nucleic acids (PNAs) as a tool to combat bacterial infection, either alone or in combination with known antimicrobial therapies.

Methods: RNA-seq analysis of the A.

Involvement of HisF in the Persistence of During a Pneumonia Infection.

is currently considered one of the most problematic nosocomial microorganisms. In the present work the gene from the ATCC 17978 strain and the AbH12O-A2 clinical isolate of was found over-expressed during the course of murine pneumonia infections. The study demonstrated that the ATCC 17978 mutant strain lacking the gene induces a sub-lethal pneumonia infection in mice, while the complemented mutant strain increased its virulence.

Therapeutic Efficacy of LN-1-255 in Combination with Imipenem in Severe Infection Caused by Carbapenem-Resistant Acinetobacter baumannii.

The carbapenem-hydrolyzing class D β-lactamases (CHDLs) are the main mechanism of carbapenem resistance in CHDLs are not effectively inactivated by clinically available β-lactam-type inhibitors. We have previously described the efficacy of the inhibitor LN-1-255 in combination with carbapenems. The aim of this study was to compare the efficacy of LN-1-255 with that of imipenem in murine pneumonia using strains carrying their most extended carbapenemases, OXA-23 and OXA-24/40.

Draft Genome Sequences of Two Epidemic OXA-48-Producing Klebsiella pneumoniae Clinical Strains Isolated during a Large Outbreak in Spain.

We report here the draft genome sequences of strains Kp1803 and Kp3380 isolated during a large outbreak at A Coruña Hospital in Spain. The final genome assemblies for Kp1803 and Kp3380 comprise approximately 6.6 and 6.

Pneumonia infection in mice reveals the involvement of the feoA gene in the pathogenesis of Acinetobacter baumannii.

Acinetobacter baumannii has emerged in the last decade as an important nosocomial pathogen. To identify genes involved in the course of a pneumonia infection, gene expression profiles were obtained from A. baumannii ATCC 17978 grown in mouse infected lungs and in culture medium.

Global assessment of small RNAs reveals a non-coding transcript involved in biofilm formation and attachment in Acinetobacter baumannii ATCC 17978.

Many strains of Acinetobacter baumannii have been described as being able to form biofilm. Small non-coding RNAs (sRNAs) control gene expression in many regulatory circuits in bacteria. The aim of the present work was to provide a global description of the sRNAs produced both by planktonic and biofilm-associated (sessile) cells of A.

Contribution of the A1S_0114 Gene to the Interaction with Eukaryotic Cells and Virulence.

Genetic and functional studies showed that some components of the ATCC 17978 A1S_0112-A1S_0119 gene cluster are critical for biofilm biogenesis and surface motility. Recently, our group has shown that the A1S_0114 gene was involved in biofilm formation, a process related with pathogenesis. Confirming our previous results, microscopy images revealed that the ATCC 17978 Δ0114 derivative lacking this gene was unable to form a mature biofilm structure.

Efficient Heterostructures for Combined Interference and Plasmon Resonance Raman Amplification.

The detection, identification, and quantification of different types of molecules and the optical imaging of, for example, cellular processes are important challenges. Here, we present how interference-enhanced Raman scattering (IERS) in adequately designed heterostructures can provide amplification factors relevant for both detection and imaging. Calculations demonstrate that the key factor is maximizing the absolute value of the refractive indices' difference between dielectric and metal layers.

The FhaB/FhaC two-partner secretion system is involved in adhesion of Acinetobacter baumannii AbH12O-A2 strain.

Acinetobacter baumannii is a hospital-acquired pathogen that shows an extraordinary capacity to stay in the hospital environment. Adherence of the bacteria to eukaryotic cells or to abiotic surfaces is the first step for establishing an infection. The A.