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Wyniki wyszukiwania dla: VIRULENCE
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Virulence
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Virulence of Clinical Candida Isolates
PublikacjaThe factors enablingCandidaspp. infections are secretion of hydrolytic enzymes, adher-ence to surfaces, biofilm formation or morphological transition, and fitness attributes. The aim of thisstudy was to investigate the correlation between known extracellular virulence factors and survivalofGalleria mellonellalarvae infected with clinicalCandida. The 25 isolates were tested and the activityof proteinases among 24/24, phospholipases...
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The Role of Proteases in the Virulence of Plant Pathogenic Bacteria
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Studies of Streptococcus anginosus Virulence in Dictyostelium discoideum and Galleria mellonella Models
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Biofilm formation as a virulence determinant of uropathogenic Escherichia coli Dr+ strains
PublikacjaInfekcje dróg moczowych stanowią największy problem zdrowotny dotykający miliony osób populacji ludzkiej każdego roku. Uropatogenne szczepy Escherichia coli są najczęstszym czynnikiem etiologicznym odpowiedzialnym za wywoływanie górnych i dolnych dróg moczowych. Powyższe szczepy bakteryjne produkują szereg czynników wirulentnych pośród, których wyróżnić można eksponowane powierzchniowo polimeryczne struktury adhezyjne (fimbrie/pile)...
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Disruption of homocitrate synthase genes in Candida albicans affects growth but not virulence
PublikacjaDwa geny, LYS21 i LYS22, kodujące izoformy syntazy homocytrynianowej, enzymu katalizującego pierwszy wyjątkowy etap w szlaku biosyntezy lizyny, zostały rozbite z komórkach Candida albicans z wykorzystaniem strategii ''SAT flipper''. Podwójny mutant lys21delta/lys22delta nie wykazywał aktywności syntazy homocytrynianowej, natomiast charakteryzował się auksotrofią wzrostową wobec lizyny w podłożach minimalnych, co można było odwrócić...
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Virulence analysis and antibiotic resistance of Klebsiella pneumoniae isolates from hospitalised patients in Poland
PublikacjaKlebsiella pneumoniae (KP) is a nosocomial pathogen causing difficult-to-treat infections. The presence of virulence genes and antibiotic resistance of 109 KP isolates from hospitalized patients were investigated. Among them, 68.8% were multi-drug resistant (MDR) and 59.6% produced extended-spectrum beta-lactamases (ESBLs). Metallo-β-lactamases (MBLs) were produced by 22% of isolates (mainly from anus), including 16.5% of isolates...
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Dietary Isothiocyanates, Sulforaphane and 2-Phenethyl Isothiocyanate, Effectively Impair Vibrio cholerae Virulence
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Virulence gene profiles in Staphylococcus aureus isolated from cows with subclinical mastitis in eastern Poland
PublikacjaStaphylococcus aureus is arguably the most important pathogen involved in bovine mastitis. The aim of this study was to determine the virulence gene profiles of 124 Staph. aureus isolates from subclinical mastitis in cows in eastern Poland. The presence of 30 virulence genes encoding adhesins, proteases and superantigenic toxins was investigated by PCR. The 17 different combinations of adhesin genes were identified. Occurrence...
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Virulence and Drug-Resistance of Staphylococcus aureus Strains Isolated from Venous Ulcers in Polish Patients
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Increased Levels of (p)ppGpp Correlate with Virulence and Biofilm Formation, but Not with Growth, in Strains of Uropathogenic Escherichia coli
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Antimicrobial Resistance and Virulence Characterization of Listeria monocytogenes Strains Isolated from Food and Food Processing Environments
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Genotyping and characterization of virulence factors in Escherichia coli strains isolated from patients from Polish hospital
PublikacjaZakażenia układu moczowego (UTIs - ang. urinary track infections) są jedną z najczęstszy infekcji, za które w 85% przypadków odpowiedzialne są bakterie Escherichia coli. Infekcje układu moczowego mogą prowadzić do groźnych powikłań m. in. odmiedniczkowego zapalenia nerek. Śmiertelność wśród tej grupy pacjentów wynosi 1-3%. Zakażenia układu moczowego występują również u ok. 7% kobiet ciężarnych. W pracy przebadano 82 szczepy E....
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Urinary Tract Infections Caused by K. pneumoniae in Kidney Transplant Recipients – Epidemiology, Virulence and Antibiotic Resistance
PublikacjaUrinary tract infections are the most common complication in kidney transplant recipients, possibly resulting in the deterioration of a long-term kidney allograft function and an increased risk of recipient’s death. K. pneumoniae has emerged as one of the most prevalent etiologic agents in the context of recurrent urinary tract infections, especially with multidrug resistant strains. This paper discusses the epidemiology and risk...
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Virulence, antifungal susceptibility and molecular mechanisms of echinocandin resistance among Candida isolates recovered from clinical specimens
PublikacjaFungi of the genus Candida belong to the natural microflora of healthy individuals. However, they can also be a cause of opportunistic infections especially among patients with an impaired immune system. The first line therapy of Candida infections is based on triazoles. However, in recent years there an increase of azole resistant Candida spp., in particular C. glabrata and C. krusei, has been observed. For this reason, echinocandin...
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Antibiotic resistance, virulence, and phylogenetic analysis of Escherichia coli strains isolated from free-living birds in human habitats
PublikacjaWild birds can be colonized by bacteria, which are often resistant to antibiotics and have various virulence profiles. The aim of this study was to analyze antibiotic resistance mechanisms and virulence profiles in relation to the phylogenetic group of E. coli strains that were isolated from the GI tract of wildfowl. Out of 241 faecal samples, presence of E. coli resistant to a cephalosporin (ESBL/AmpC) was estimated for 33 isolates...
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Lack of correlation between X region spa polymorphism and virulence of methicillin resistant and methicillin sensitive Staphylococcus aureus strains
PublikacjaW celu sprawdzenia zależności pomiędzy liczbą powtórzeń 24 nukleotydowej sekwencji w fragmencie X genu spa a wirulencją gronkowców przebadano populację 176 klinicznych izolatów bakterii S. aureus. 94 z nich wykazywały oporność na metycylinę (MRSA) pozostałe 82 izolaty były wrażliwe na działanie tego antybiotyku (MSSA). W obydwu grupach nie udało się potwierdzić korelacji pomiędzy wielkością amplifikowanego fragmentu - liczbą powtórzeń...
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Bacterial Pathogens in the Food Industry: Antibiotic Resistance and Virulence Factors of Salmonella enterica Strains Isolated from Food Chain Links
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Discovering the mechanisms of strain-dependent response of Staphylococcus aureus to photoinactivation: Oxidative stress toleration, endogenous porphyrin level and strain's virulence
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Effects of osmotic and high pressure stress on expression of virulence factors among Enterococcus spp. isolated from food of animal origin
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Staphylococcus aureus Co-Infection in COVID-19 Patients: Virulence Genes and Their Influence on Respiratory Epithelial Cells in Light of Risk of Severe Secondary Infection
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Characterisation of Escherichia coli isolates from the blood of haematological adult patients with bacteraemia: translocation from gut to blood requires the cooperation of multiple virulence factors
PublikacjaThe aim of the study was to investigate whether there are unique pathotypes of Escherichia coli capable of transmission from the gastrointestinal tract to the vascular bed. The study included E. coli strains isolated from clinical materials collected from 115 patients suffering from haematologic malignancies diagnosed with bacteraemia. The genotyping techniques established that 89 E. coli isolates from the blood had the same genotype...
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Recurrent bowel-blood translocations of Escherichia coli with the unique virulence characteristics over three-year period in the patient with acute myeloid leukaemia – case report
PublikacjaIn patients with haematological malignancies, the bowel remains the main source of Escherichia coli bloodstream infections. We present the clinical example of recurrent bowel-blood translocations of E. coli with the unique virulence characteristics in a 55-year-old male with the diagnosis of acute myeloid leukaemia. The virulent factors profile of examined strains confirmed that the co-existence of genes papC, sfa, usp and cnf1,...
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Comparative genomics, pangenomics, and phenomic studies of Pectobacterium betavasculorum strains isolated from sugar beet, potato, sunflower, and artichoke: insights into pathogenicity, virulence determinants, and adaptation to the host plant
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The Many Faces of Enterococcus spp.—Commensal, Probiotic and Opportunistic Pathogen
PublikacjaEnterococcus spp. are Gram-positive, facultative, anaerobic cocci, which are found in the intestinal flora and, less frequently, in the vagina or mouth. Enterococcus faecalis and Enterococcus faecium are the most common species found in humans. As commensals, enterococci colonize the digestive system and participate in the modulation of the immune system in humans and animals. For many years reference enterococcal strains have...
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Escherichia coli Strains with Virulent Factors Typical for Uropathogens were Isolated from Sinuses from Patients with Chronic Rhinosinusitis—Case Report
PublikacjaEscherichia coli were isolated from three patients with chronic rhinosinusitis (CRS) by intraoperative sinus tissue biopsy. Taking into account the unusual replicative niche and previous treatment failures, it was decided to focus on the virulence and drug resistance of these bacteria. The strains turned out to be multi-sensitive, but the rich virulence factors profile of bacteria typical for phylogenetic group B2 deserved attention....
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Intra-operative biopsy in chronic sinusitis detects pathogenic Escherichia coli that carry fimG/H, fyuA and agn43 genes coding biofilm formation
PublikacjaThe aim of this study was to investigate whether or not surgical biopsy of sinus tissue in chronic sinusitis, not responsive to treatment, would detect E. coli. We intended to evaluate E. coli virulence genes, therefore dispute the causal role of such an unusual microorganism in chronic sinusitis, as well as consider effective pathogen-targeted therapy. Patients with E. coli isolated by intra-operative puncture biopsy were included...
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Phenotypic consequences of LYS4 gene disruption in Candida albicans
PublikacjaA BLAST search of the Candida Genome Database with the Saccharomyces cerevisiae LYS4 sequence known to encode homoaconitase (HA) revealed ORFs 19.3846 and 19.11327. Both alleles of the LYS4 gene were sequentially disrupted in Candida albicans BWP17 cells using PCR-based methodology. The null lys4Δ mutant exhibited lysine auxotrophy in minimal medium but was able to grow in the presence of L-Lys and α-aminoadipate, an intermediate...
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Beata Krawczyk dr hab.
Osobydr hab. Beata Krawczyk, prof. uczelni Stopnie naukowe, wykształcenie, kwalifikacje Beata Krawczyk uzyskała tytuł magistra biologii na Wydziale Biologii (wówczas: Wydział Biologii i Nauk o Ziemi), Uniwersytetu Gdańskiego w 1986 roku, a doktorat z biologii molekularnej na Wydziale Biologii (wówczas: Wydział Biologii, Geografii i Oceanologii) Uniwersytetu Gdańskiego w 1996 roku. Stopień doktora habilitowanego w zakresie nauk biologicznych...
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Plasmids pMET2M1 and pMET15M1 with the SAT1 Flipper knockout cassette construction
Dane BadawczeThe goal of the study was to obtain plasmids containing the SAT1 Flipper knockout cassette along with upstream and downstream gene fragments (MET2, MET15) and to introduce a cleavage site for restriction enzymes into them.
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Inserts amplification for knockout cassette construction
Dane BadawczeThe goal of the study was to obtain optimal conditions for amplification of upstream and downstream genes fragments and introduce a cleavage site for restriction enzymes into them thanks to which it will be possible to clone fragments into a plasmid containing elements of the knockout cassette. The constructed cassettes will enable the removal of the...
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A new assay for simultaneous identification and differentiation of Klebsiella oxytoca strains
PublikacjaBacterial strain typing, or identifying bacteria at the strain level, is particularly important for diagnosis, treatment, and epidemiological surveillance of bacterial infections. This is especially the case for bacteria exhibiting high levels of antibiotic resistance or virulence, and those involved in nosocomial or pandemic infections. Strain typing also has applications in studying bacterial population dynamics.
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Regulated Control of the Assembly and Diversity of LPS by Noncoding sRNAs
PublikacjaThe outer membrane (OM) of Gram-negative bacteria is asymmetric due to the presence of lipopolysaccharide (LPS) facing the outer leaflet of the OM and phospholipids facing the periplasmic side. LPS is essential for bacterial viability, since it provides a permeability barrier and is a major virulence determinant in pathogenic bacteria. In Escherichia coli, several steps of LPS biosynthesis and assembly are regulated by the RpoE...
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May Staphylococcus lugdunensis Be an Etiological Factor of Chronic Maxillary Sinuses Infection?
PublikacjaStaphylococcus lugdunensis is an opportunistic pathogen found in the healthy human skin microbiome bacterial community that is able to cause infections of diverse localization, manifestation, and course, including laryngological infections, such as necrotizing sinusitis. Chronic maxillary sinusitis is a disease present in up to one third of European and American populations, and its etiology is not fully described. Within this...
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Phylogenetic relationship and antimicrobial resistance in Escherichia coli isolated from the Reda River and the Oliwski Stream, Northern Poland = Lekooporność i przynależność filogenetyczna szczepów Escherichia Coli izolowanych z rzeki Redy i Potoku Oliwskiego
PublikacjaThe high abundance of fecal bacteria in surface water is usually related to poor agricultural practice, pollution caused by domesticated and wild animals as well as with septic tank failures. Identification of fecal contamination sources seems to be crucial in order to effectively estimate the inherent risk. In this study, the phylogenetic relationship of 30 isolates of E. coli, originated from surface water, was estimated by employing...
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A subset of two adherence systems, acute pro-inflammatory pap genes and invasion coding dra, fim, or sfa, increases the risk of Escherichia coli translocation to the bloodstream
PublikacjaAn analysis of the phylogenetic distribution and virulence genes of Escherichia coli isolates which predispose this bacteria to translocate from the urinary tract to the bloodstream is presented. One-dimensional analysis indicated that the occurrence of P fimbriae and α-hemolysin coding genes is more frequent among the E. coli which cause bacteremia. However, a two-dimensional analysis revealed that a combination of genes coding...
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Inhibitors of amino acids biosynthesis as antifungal agents
PublikacjaFungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit...
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Biofilm formation and its regulation in Staphylococcus aureus
PublikacjaInfections caused by the major human and animal pathogen, Staphylococcus aureus are becoming an important problem due to its emerging resistance mechanisms and variety of virulence factors. Biofilm formation is considered to be one of the most important factor attributed to high pathogenicity of S. aureus. Described in the literature methods used in identification of biofilm forming abilities of bacteria consist of phenotypic and...
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Molecular Targets for Anticandidal Chemotherapy
PublikacjaA relatively small number of anticandidal chemotherapeutics used in clinical practice is at least in part consequence of a limited number of their molecular targets: ergosterol in the membrane, lanosterol demethylase, b(1!3) glucan synthase, and DNA/RNA biosynthesis. Much more potential novel targets have been revealed by the comparative genomic studies identifying essential genes unique for Candida albicans or resulted from recognition...
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Consequences of lysine auxotrophy for Candida albicans adherence and biofilm formation
PublikacjaA number of factors are known to be involved in Candida albicans virulence, although biofilm development on the surfaces of indwelling medical devices is considered to promote superficial or systemic disease. Based on previously reported up-regulation of saccharopine and acetyllysine in biofilm cells and activation of the lysine biosynthesis/degradation pathway, we investigated...
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Alternative treatment approaches of urinary tract infections caused by uropathogenic Escherichia coli strains
PublikacjaUrinary tract infections (UTIs) are the most widespread and annoying infections affecting millions of people every year annually. The biggest problem of urinary diseases are recurrences, the increasing resistance of uropathogens to commonly used antibiotics, as well as the high health care costs of afflicted persons. Uropathogenic Escherichia coli strains (UPECs) are the most dominant etiologic agent of community-acquired infections...
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Insights into oral microbiome and colorectal cancer – on the way of searching new perspectives
PublikacjaMicrobiome is a keystone polymicrobial community that coexist with human body in a beneficial relationship. These microorganisms enable the human body to maintain homeostasis and take part in mechanisms of defense against infection and in the absorption of nutrients. Even though microbiome is involved in physiologic processes that are beneficial to host health, it may also cause serious detrimental issues. Additionally, it has been...
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Biochemical characteristic of biofilm of uropathogenic Escherichia coli Dr+ strains.
PublikacjaUrinary tract infections caused by Escherichia coli are very common health problem in the developed countries. The virulence of the uropathogenic E. coli Dr+ IH11128 is determined by Dr fimbriae, which are homopolymeric structures composed of DraE subunits with the DraD protein capping the fiber. In this study, we have analyzed the structural and biochemical properties of biofilms developed by E. coli strains expressing Dr fimbriae...
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The New Klebsiella pneumoniae ST152 Variants with Hypermucoviscous Phenotype Isolated from Renal Transplant Recipients with Asymptomatic Bacteriuria-Genetic Characteristics by WGS.
PublikacjaKlebsiella pneumoniae (Kp) is one of the most important etiological factors of urinary tract infections in renal transplant (RTx) recipients. We described the antimicrobial susceptibility phenotypes and genomic features of two hypermucoviscous (HM) Kp isolates recovered from RTx recipients with asymptomatic bacteriuria (ABU). Using whole genome sequencing (WGS) data, we showed that the strains belong to the ST152 lineage with the...
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In Silico Safety Assessment of Bacillus Isolated from Polish Bee Pollen and Bee Bread as Novel Probiotic Candidates
PublikacjaBacillus species isolated from Polish bee pollen (BP) and bee bread (BB) were characterized for in silico probiotic and safety attributes. A probiogenomics approach was used, and in-depth genomic analysis was performed using a wide array of bioinformatics tools to investigate the presence of virulence and antibiotic resistance properties, mobile genetic elements, and secondary metabolites. Functional annotation and Carbohydrate-Active...
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Regulated Assembly of LPS, Its Structural Alterations and Cellular Response to LPS Defects
PublikacjaDistinguishing feature of the outer membrane (OM) of Gram-negative bacteria is its asymmetry due to the presence of lipopolysaccharide (LPS) in the outer leaflet of the OM and phospholipids in the inner leaflet. Recent studies have revealed the existence of regulatory controls that ensure a balanced biosynthesis of LPS and phospholipids, both of which are essential for bacterial viability. LPS provides the essential permeability...
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Phenotypic consequences of the LYS4 gene disruption in Candida albicans
PublikacjaThe main scientific purpose of our studies was to verify the hypothesis that homoaconitase (HA) from Candida albicans, an enzyme catalyzing a second step of the α-aminoadipate pathway (AAP) of L-Lys biosynthesis may become a new target for antifungal chemotherapy. Previous studies indicated that the A. fumigatus mutant lacking the functional lysF gene, encoding HA, exhibited attenuated virulence in a low-dose mouse infection model...
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Enzymes of the lysine biosynthetic pathway as targets for antifungals ?
PublikacjaSystemic infections caused by human pathogenic fungi in immunocompromized patients continue to be one of the important clinical problems. Limited availability of safe and efficacious antifungal chemotherapeutics and emerging resistance to existing drugs stimulates search for novel molecular targets for antifungals. The α-aminoadipate pathway (AAP) of L-lysine biosynthesis is unique in fungi and thus has been so far considered...
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Identification of antigen Ag43 in uropathogenic Escherichia coli Dr+ strains and defining its role in the pathogenesis of urinary tract infections
PublikacjaUrinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) are among the most common bacterial infectious diseases in the developed world. The urovirulence of UPEC is mainly associated with the surface-exposed fimbrial adhesins and adhesins of the autotransporter (AT) family. The best studied of theses proteins is antigen 43 (Ag43) mediating cell aggregation, adhesion and biofilm development as the causes of...
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Genetic Background and Antibiotic Resistance Profiles of K. pneumoniae NDM-1 Strains Isolated from UTI, ABU, and the GI Tract, from One Hospital in Poland, in Relation to Strains Nationally and Worldwide
PublikacjaIn recent years, there has been an observed increase in infections caused by carbapenem-resistant Klebsiella pneumonia (Kp) strains. The aim of this study was the phenotypic and genotypic analysis of eight K. pneumoniae NDM (Kp NDM) isolates, recovered in Poland during the years 2016 and 2018 from seven patients with urinary tract infections (UTIs), asymptomatic bacteriuria (ABU), or colonization of the gut. PCR melting profile...