Antimicrobial activity of prophage endolysins against critical Enterobacteriaceae antibiotic-resistant bacteria.

Enterobacteriaceae species are part of the 2017 World Health Organization antibiotic-resistant priority pathogens list for development of novel medicines. Multidrug-resistant Klebsiella pneumoniae is an increasing threat to public health and has become a relevant human pathogen involved in life-threatening infections. Phage therapy involves the use of phages or their lytic endolysins as bioagents for the treatment of bacterial infectious diseases.

Virulence factors in carbapenem-resistant hypervirulent .

Hypervirulence and carbapenem-resistant have emerged as two distinct evolutionary pathotypes of , with both reaching their epidemic success and posing a great threat to public health. However, as the boundaries separating these two pathotypes fade, we assist a worrisome convergence in certain high-risk clones, causing hospital outbreaks and challenging every therapeutic option available. To better understand the basic biology of these pathogens, this review aimed to describe the virulence factors and their distribution worldwide among carbapenem-resistant highly virulent or hypervirulent strains, as well as to understand the interplay of these virulence strains with the carbapenemase produced and the sequence type of such strains.

Emergence of KPC-3- and OXA-181-producing ST13 and ST17 Klebsiella pneumoniae in Portugal: genomic insights on national and international dissemination.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) strains are of particular concern, especially strains with mobilizable carbapenemase genes such as blaKPC, blaNDM or blaOXA-48, given that carbapenems are usually the last line drugs in the β-lactam class and, resistance to this sub-class is associated with increased mortality and frequently co-occurs with resistance to other antimicrobial classes.

Objectives: To characterize the genomic diversity and international dissemination of CRKP strains from tertiary care hospitals in Lisbon, Portugal.

Methods: Twenty CRKP isolates obtained from different patients were subjected to WGS for species confirmation, typing, drug resistance gene detection and phylogenetic reconstruction.

Liposomal Delivery of Newly Identified Prophage Lysins in a Model.

is a Gram-negative opportunistic bacterium that presents resistance to several antibiotics, thus, representing a major threat to human and animal health. Phage-derived products, namely lysins, or peptidoglycan-hydrolyzing enzymes, can be an effective weapon against antibiotic-resistant bacteria. Whereas in Gram-positive bacteria, lysis from without is facilitated by the exposed peptidoglycan layer, this is not possible in the outer membrane-protected peptidoglycan of Gram-negative bacteria.

Genomic epidemiological analysis of Klebsiella pneumoniae from Portuguese hospitals reveals insights into circulating antimicrobial resistance.

Klebsiella pneumoniae (Kp) bacteria are an increasing threat to public health and represent one of the most concerning pathogens involved in life-threatening infections and antimicrobial resistance (AMR). To understand the epidemiology of AMR of Kp in Portugal, we analysed whole genome sequencing, susceptibility testing and other meta data on 509 isolates collected nationwide from 16 hospitals and environmental settings between years 1980 and 2019. Predominant sequence types (STs) included ST15 (n = 161, 32%), ST147 (n = 36, 7%), ST14 (n = 26, 5%) or ST13 (n = 26, 5%), while 31% of isolates belonged to STs with fewer than 10 isolates.

Quality assessment of Portuguese monofloral honeys. Physicochemical parameters as tools in botanical source differentiation.

The quality evaluation and physicochemical parameters assessment of Portuguese monofloral honeys were performed. Fifty-one monofloral honeys were collected from several regions from mainland Portugal, and from the Azores islands, producer labelled as carob tree (n = 5), chestnut (n = 2), eucalyptus (n = 5), bell heather (n = 6), incense (n = 4), lavender (n = 8), orange (n = 9), rape (n = 2), raspberry (n = 2), rosemary (n = 1), sunflower (n = 3), and strawberry tree (n = 4). Pollen analysis and microbiological safety were evaluated, and the parameters such as colour index, moisture content, electrical conductivity, hydroxymethylfurfural, pH, free and total acidity, diastase activity, proline, and sugar profile were assessed for physicochemical characterization, in all 51 monofloral honeys.

A phylogenomic approach for the analysis of colistin resistance-associated genes in Klebsiella pneumoniae, its mutational diversity and implications for phenotypic resistance.

The emergence of carbapenemase-producing Klebsiella pneumoniae strains has triggered the use of old antibiotics such as colistin. This is driving the emergence of colistin resistance in multidrug-resistant strains that underlie life-threatening infections. This study analyses the mutational diversity of 22 genes associated with colistin resistance in 140 K.

Whole-Genome Sequencing Enables Molecular Characterization of Non-Clonal Group 258 High-Risk Clones (ST13, ST17, ST147 and ST307) among Carbapenem-Resistant from a Tertiary University Hospital Centre in Portugal.

The carbapenem-resistant Enterobacterales (CRE) strains have been identified by the World Health Organization as critical priority pathogens in research and development of diagnostics, treatments, and vaccines. However, recent molecular information about carbapenem-resistant (CRK) epidemiology in Portugal is still scarce. Thus, this study aimed to provide the molecular epidemiology, resistome, and virulome of CRK clinical strains recovered from a tertiary care hospital centre (2019-2021) using polymerase chain reaction (PCR) and the advanced molecular technique whole-genome sequencing (WGS).

First Outbreak of NDM-1-Producing ST11 in a Portuguese Hospital Centre during the COVID-19 Pandemic.

New Delhi metallo-β-lactamase (NDM) carbapenemase has been considered a global threat due to its worldwide widespread in recent years. In Portugal, a very low number of infections with NDM-producing Enterobacterales has been reported. A total of 52 strains from 40 patients and 1 environmental sample isolated during COVID-19 pandemic were included in this study.

First Description of Ceftazidime/Avibactam Resistance in a ST13 KPC-70-Producing Strain from Portugal.

The combination of ceftazidime/avibactam (CZA) is a novel β-lactam/β-lactamase inhibitor with activity against carbapenemase (KPC)-producing Enterobacterales. Emerging cases caused by CZA-resistant strains that produce variants of KPC genes have already been reported worldwide. However, to the best of our knowledge, no CZA-resistant strains were reported in Portugal.

and Colistin Susceptibility Testing: Performance Evaluation for Broth Microdilution, Agar Dilution and Minimum Inhibitory Concentration Test Strips and Impact of the "Skipped Well" Phenomenon.

The emergence of multidrug resistant Gram-negative pathogens, particularly carbapenemase producers, has forced clinicians to use last line antibiotics, such as colistin. Since colistin susceptibility testing presents several challenges, this study aimed at evaluating the performance of two alternative susceptibility methods for , namely, agar dilution (AD) and MIC test strips (MTS). These approaches were compared with the reference method, broth microdilution (BMD), and provide a quantitative description for the "skipped well" (SW) phenomenon.

Black-and-White Ruffed Lemur () in Captivity: Analysis of the Oral Microbiota in a One Health Perspective.

This study aimed to characterize the susceptibility profile to antibiotics and biofilm formation of Gram-negative bacterial isolates obtained from the oral cavity of the black-and-white ruffed lemur (). From eight individuals from a zoo located in Portugal, samples of the oral microbiota were collected with sterile swabs and then placed in closed tubes with a transport medium. Culture was carried out for media of Gram-negative bacteria.

A Molecular Perspective on Colistin and : Mode of Action, Resistance Genetics, and Phenotypic Susceptibility.

is a rod-shaped, encapsulated, Gram-negative bacteria associated with multiple nosocomial infections. Multidrug-resistant (MDR) strains have been increasing and the therapeutic options are increasingly limited. Colistin is a long-used, polycationic, heptapeptide that has regained attention due to its activity against Gram-negative bacteria, including the MDR strains.

An Update on Wastewater Multi-Resistant Bacteria: Identification of Clinical Pathogens Such as O25b:H4-B2-ST131-Producing CTX-M-15 ESBL and KPC-3 Carbapenemase-Producing .

Wastewater treatment plants (WWTPs) are significant reservoirs of bacterial resistance. This work aims to identify the determinants of resistance produced by Gram-negative bacteria in the influent and effluent of two WWTPs in Portugal. A total of 96 wastewater samples were obtained between 2016 and 2019.

Methylation analysis of Klebsiella pneumoniae from Portuguese hospitals.

Klebsiella pneumoniae is an important nosocomial infectious agent with a high antimicrobial resistance (AMR) burden. The application of long read sequencing technologies is providing insights into bacterial chromosomal and putative extra-chromosomal genetic elements (PEGEs) associated with AMR, but also epigenetic DNA methylation, which is thought to play a role in cleavage of foreign DNA and expression regulation. Here, we apply the PacBio sequencing platform to eight Portuguese hospital isolates, including one carbapenemase producing isolate, to identify methylation motifs.

Genomic Epidemiology of Carbapenemase Producing Strains at a Northern Portuguese Hospital Enables the Detection of a Misidentified KPC-3 Producing Strain.

The evolutionary epidemiology, resistome, virulome and mobilome of thirty-one multidrug resistant clinical isolates from the northern Vila Real region of Portugal were characterized using whole-genome sequencing and bioinformatic analysis. The genomic population structure was dominated by two main sequence types (STs): ST147 ( = 17; 54.8%) and ST15 ( = 6; 19.

Whole-genome sequencing resolves a polyclonal outbreak by extended-spectrum beta-lactam and carbapenem-resistant in a Portuguese tertiary-care hospital.

has emerged as an important nosocomial pathogen, with whole-genome sequencing (WGS) significantly improving our ability to characterize associated outbreaks. Our study sought to perform a genome-wide analysis of multiclonal isolates (=39; 23 patients) producing extended spectrum beta-lactamases and/or carbapenemases sourced between 2011 and 2016 in a Portuguese tertiary-care hospital. All isolates showed resistance to third-generation cephalosporins and six isolates (five patients) were also carbapenem resistant.

Community- and Hospital-Acquired Urinary Tract Infections in Portugal: Virulence and Antibiotic Resistance.

is a clinically relevant pathogen and a frequent cause of hospital-acquired (HA) and community-acquired (CA) urinary tract infections (UTI). The increased resistance of this pathogen is leading to limited therapeutic options. To investigate the epidemiology, virulence, and antibiotic resistance profile of in urinary tract infections, we conducted a multicenter retrospective study for a total of 81 isolates (50 CA-UTI and 31 HA-UTI) in Portugal.

The potato cyst nematode effector RHA1B is a ubiquitin ligase and uses two distinct mechanisms to suppress plant immune signaling.

Plant pathogens, such as bacteria, fungi, oomycetes and nematodes, rely on wide range of virulent effectors delivered into host cells to suppress plant immunity. Although phytobacterial effectors have been intensively investigated, little is known about the function of effectors of plant-parasitic nematodes, such as Globodera pallida, a cyst nematode responsible for vast losses in the potato and tomato industries. Here, we demonstrate using in vivo and in vitro ubiquitination assays the potato cyst nematode (Globodera pallida) effector RHA1B is an E3 ubiquitin ligase that employs multiple host plant E2 ubiquitin conjugation enzymes to catalyze ubiquitination.

Starch-Based Pickering Emulsions as Platforms for Topical Antibiotic Delivery: In Vitro and In Vivo Studies.

The present study investigated a new approach to treat superficial skin infections by topical application of minocycline hydrochloride (MH) formulated in a novel starch-based Pickering emulsion (ASt-emulsions). The emulsions were fully characterized in terms of efficacy, as well as in vitro release and permeation studies. The emulsions provided a prolonged MH release, always above its minimum inhibitory concentration against , although the drug did not permeate through the entire skin layer.

Cross-sectional study of adenoidal biofilms in a paediatric population and its clinical implications.

Introduction: Adenoids are nasopharyngeal lymphoid tissue with a relevant role in host defence against infection of upper respiratory tract. Nevertheless, adenoids are also a reservoir of microorganisms that can cause infections of upper respiratory tract and otitis particularly in children.

Objective: Evaluate and compare the association between biofilm assembly on adenoids and the incidence of recurrent infections in a paediatric population submitted to adenoidectomy by either infectious or non-infectious indication.

Virulence and resistance determinants of Klebsiella pneumoniae isolated from a Portuguese tertiary university hospital centre over a 31-year period.

Introduction: The rapid and complex evolution of bacterial resistance mechanisms in Klebsiella pneumoniae producing extended-spectrum β-lactamases and carbapenemases in Klebsiella pneumoniae is one of the most significant threats to public health. However, questions and controversies regarding the interactions between resistance and virulence in multidrug-resistant K. pneumoniae isolates remain unclear.

First Description of Colistin and Tigecycline-Resistant Producing KPC-3 Carbapenemase in Portugal.

Herein, we describe a case report of carbapenem-resistant and isolates that were identified from the same patient at a Tertiary University Hospital Centre in Portugal. Antimicrobial susceptibility and the molecular characterization of resistance and virulence determinants were performed. PCR screening identified the presence of the resistance genes , and in both isolates.