A novel barna-like virus was found to be associated with field-collected plant-parasitic nematodes. The positive-sense, single-stranded RNA genome of this virus, named Afrina barna-like virus (AfBLV), comprises 4020 nucleotides encoding four open reading frames (ORFs). ORF 1 encodes a protein product spanning a transmembrane, a peptidase, and VPg domains, whereas an overlapping ORF 2 encodes an RNA-dependent RNA polymerase (RdRP).
View Article and Find Full Text PDFBackground: Carbapenem-resistant Klebsiella pneumoniae (CRKP) has high incidence in Portugal, causing severe and often fatal infections.
Objectives: Characterize the evolutionary history and epidemiology of CRKP in Portugal over a 40-year period.
Methods: WGS was performed using the Illumina platform.
Annu Rev Phytopathol
September 2025
Annual ryegrass toxicity (ARGT) has caused significant economic damage in Australia. This syndrome occurs when is carried by a seed gall nematode into the developing seeds of forage grasses, where it produces a tunicamycin toxin. Grazing animals feeding on infected plants die when they consume sufficient toxin.
View Article and Find Full Text PDFis a Gram-negative opportunistic pathogen, responsible for nosocomial infections worldwide. In recent years, this microorganism has acquired resistance to various antibiotics, prompting the World Health Organization (WHO) to declare carbapenem-resistant (CRAB) a critical priority microorganism requiring urgent attention and the development of new therapeutic options. Here, we screened for prophages in 158 genomes of , comprising 139 complete genomes from the Bacterial and Viral Bioinformatics Resource Center (BV-BRC), and 19 newly sequenced clinical isolates.
View Article and Find Full Text PDFMed Microbiol Immunol
January 2025
\nKlebsiella pneumoniae is a common pathogen of healthcare-associated infections expressing a plethora of antimicrobial resistance loci, including ADP-ribosyltransferase coding genes (arr), able to mediate rifampicin resistance. The latter has activity against a broad range of microorganisms by inhibiting DNA-dependent RNA polymerases. This study aims to characterise the arr distribution and genetic context in 138 clinical isolates of K.
View Article and Find Full Text PDFEnterobacteriaceae 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.
View Article and Find Full Text PDFHypervirulence 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.
View Article and Find Full Text PDFBackground: 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.
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.
View Article and Find Full Text PDFKlebsiella 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFThe 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).
View Article and Find Full Text PDFNew 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.
View Article and Find Full Text PDFAntibiotics (Basel)
January 2022
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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFThis 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.
View Article and Find Full Text PDFDiagnostics (Basel)
June 2021
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.
View Article and Find Full Text PDFWastewater 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.
View Article and Find Full Text PDFKlebsiella 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.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFhas 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.
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