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1.
Pathogens ; 12(11)2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-38003810

RESUMEN

Pregnancy is associated with a 5-26 times increased risk of invasive Haemophilus influenzae infection and subsequent adverse pregnancy outcomes. Incidence rate and outcome are published in some regions, but the characterisation of bacterial isolates is limited. We performed comparative genomic analyses of isolates from 12 pregnancy-associated cases, cultured from maternal bacteraemia in pregnancy (nine), postpartum bacteraemia (one), neonatal bacteraemia (one), and placental tissue (one). In two bacteraemia cases, identical isolates were also cultured from cervical swabs. Eight cases occurred early in pregnancy (gestational week 7-26), and seven of them resulted in miscarriage or neonatal death. All bacterial genomes were devoid of capsule loci, and they were evenly distributed in the major phylogenetic group I of the species. The conspicuous tropism of H. influenzae for pregnancy and placental tissue is associated with the species rather than specific clonal subtypes.

2.
J Environ Manage ; 348: 119271, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37827073

RESUMEN

Biochar is a product rich in carbon produced by pyrolysis of different kinds of biomass and it modifies the physical, chemical, and biological properties of soil. In this study, biochar, produced at different pyrolysis temperatures (590 °C, 665 °C, and 765 °C), was physico-chemically characterized. It was explored whether biochar made from sewage sludge can become an alternative solution for future water and phosphorus management in agricultural production. A pot experiment was conducted using Chinese cabbage (Brassica rapa subsp. pekinensis) to investigate the effect of applying different biochars to the substrate, taking into account different growth parameters and the biochemical composition of the plants, as well as the physico-chemical properties of the substrate. According to the results, pyrolysis temperature influences the content of elements in biochar and their availability to plants, with total phosphorus contents in biochar ranging from 4.6% to 4.9%. In addition, applying biochar to the substrate significantly increases the volumetric water content up to 4.5 fold more compared to the control, which indicates a promising application in drought stress conditions and, at the same time, is a source of nutrients and can help to reduce the amount of mineral fertilizer application.


Asunto(s)
Carbón Orgánico , Aguas del Alcantarillado , Aguas del Alcantarillado/química , Carbón Orgánico/química , Suelo/química , Agua/química , Fósforo/química
3.
Eur J Clin Microbiol Infect Dis ; 40(10): 2077-2085, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33891188

RESUMEN

Haemophilus influenzae is a common cause of mucosal infections that warrants accurate surveillance. We aimed to assess the prevalence of the species in clinical specimens, and characterise population structure and resistance to aminopenicillins by whole genome sequencing.We assessed the point prevalence by entering the database records of 1 day in Denmark and examined the genome sequences of nationwide, collected isolates from the same day. The prevalence of H. influenzae in clinical samples on the 10th of January 2018 was 1.78 per 100,000 person-days (all samples), and 2.47 per 1000 hospital bed-days (hospital samples). Of 2009 bacteria deemed clinically relevant and collected in a concerted action by the Danish departments of clinical microbiology, 62 (3.1%) were H. influenzae. All 62 isolates belonged to phylogenetic group I and were unencapsulated. Three strains from separate Danish regions had identical core genome sequences, but a small number of intergenic mutations testified to circulating clones, rather than individual cases of patient-to-patient transmission. The TEM-1 ß-lactamase gene was present in 24 strains, while 13 strains were genetically categorised as ampicillin-resistant due to substitutions in penicillin-binding protein 3; shared patterns of amino acid substitutions in unrelated strains indicated putative lateral transfer of chromosomal resistance. Circulating clones of H. influenzae are frequent, and host factors, rather than direct transmission of epidemic strains, may be the primary cause of infection. The bleak presence of ampicillin resistance revealed by sequencing of point prevalence strains underscores the necessity for close examination of testing methods.


Asunto(s)
Resistencia a la Ampicilina , Antibacterianos/farmacología , Infecciones por Haemophilus/microbiología , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/aislamiento & purificación , Ampicilina/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Dinamarca/epidemiología , Infecciones por Haemophilus/epidemiología , Haemophilus influenzae/clasificación , Haemophilus influenzae/genética , Humanos , Filogenia , beta-Lactamasas/genética , beta-Lactamasas/metabolismo
4.
mBio ; 11(3)2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32430467

RESUMEN

Escherichia coli sequence type 131 (ST131) is a major cause of urinary and bloodstream infections. Its association with extended-spectrum ß-lactamases (ESBLs) significantly complicates treatment. Its best-described component is the rapidly expanding H30Rx clade, containing allele 30 of the type 1 fimbrial adhesin gene fimH This lineage appears to have emerged in the United States and spread around the world in part due to the acquisition of the ESBL-encoding blaCTX-M-15 gene and resistance to fluoroquinolones. However, non-H30 ST131 sublineages with other acquired CTX-M-type resistance genes are also emerging. Based on whole-genome analyses, we describe here the presence of an (fimH) H27 E. coli ST131 sublineage that has recently caused an outbreak of community-acquired bacteremia and recurrent urinary tract infections (UTIs) in Denmark. This sublineage has acquired both a virulence plasmid (pAA) that defines the enteroaggregative E. coli (EAEC) diarrheagenic pathotype and multiple genes associated with extraintestinal E. coli (ExPEC); combined, these traits have made this particular ST131 sublineage successful at colonizing its human host and causing recurrent UTI. Moreover, using a historic World Health Organization (WHO) E. coli collection and publicly available genome sequences, we identified a global H27 EAEC ST131 sublineage that dates back as far as 1998. Most H27 EAEC ST131 isolates harbor pAA or pAA-like plasmids, and our analysis strongly implies a single ancestral acquisition among these isolates. These findings illustrate both the profound plasticity of this important pathogenic E. coli ST131 H27 sublineage and genetic acquisitions of EAEC-specific virulence traits that likely confer an enhanced ability to cause intestinal colonization.IMPORTANCEE. coli ST131 is an important extraintestinal pathogenic lineage. A signature characteristic of ST131 is its ability to asymptomatically colonize the gastrointestinal tract and then opportunistically cause extraintestinal infections, such as cystitis, pyelonephritis, and urosepsis. In this study, we identified an ST131 H27 sublineage that has acquired the enteroaggregative diarrheagenic phenotype, spread across multiple continents, and caused multiple outbreaks of community-acquired ESBL-associated bloodstream infections in Denmark. The strain's ability to both cause diarrhea and innocuously colonize the human gastrointestinal tract may facilitate its dissemination and establishment in the community.


Asunto(s)
Bacteriemia/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/genética , Escherichia coli/patogenicidad , Infecciones Urinarias/microbiología , Antibacterianos/farmacología , Bancos de Muestras Biológicas , Infecciones Comunitarias Adquiridas/microbiología , Dinamarca , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli/efectos de los fármacos , Genoma Bacteriano , Humanos , Tipificación de Secuencias Multilocus , Filogenia , Plásmidos/genética , Análisis de Secuencia de ADN , Virulencia/genética , Secuenciación Completa del Genoma , Organización Mundial de la Salud
5.
J Med Microbiol ; 69(3): 387-395, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31958049

RESUMEN

Introduction. Cefuroxime is an important antibiotic to treat several serious infections. Rapid elimination through the kidneys and the variation in MICs of various susceptible pathogens such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Streptococcus pneumoniae give rise to dosing issues, especially in otherwise healthy patients.Aim. To investigate the probability of target attainment (PTA) for obtaining the optimal dosage regimens for cefuroxime in healthy young people.Methodology. Two weeks apart 750 and 1500 mg cefuroxime were administered as an intravenous bolus to 20 healthy volunteers (mean age: 27 years). Population modelling and simulation studies were done based on the obtained data for cefuroxime plasma concentration.Results. With a target value of time above MIC (T >MIC) greater than 50 % the simulations revealed that a PTA of >99 % is obtained for S. pneumoniae with a dosage regimen of 750 mg q12h. For E. coli and K. pneumoniae the PTA was <90 % even with the highest, simulated dosage of 1500 mg q6h. For S. aureus a dosage of 1500 mg q8h gave a PTA above 97 %.Conclusions. S. pneumoniae is most likely treatable with a two-daily dose of 750 mg cefuroxime. Not treatable are K. pneumoniae and E. coli. For S. aureus 1500 mg q8h constitutes an optimal dosing schedule.


Asunto(s)
Antibacterianos/farmacocinética , Cefuroxima/farmacocinética , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones Estafilocócicas/tratamiento farmacológico , Adulto , Antibacterianos/administración & dosificación , Cefuroxima/administración & dosificación , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/microbiología , Femenino , Voluntarios Sanos , Humanos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Método de Montecarlo , Infecciones Estafilocócicas/microbiología , Staphylococcus/efectos de los fármacos , Streptococcus pneumoniae/efectos de los fármacos , Adulto Joven
7.
J Antimicrob Chemother ; 74(3): 557-560, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30496481

RESUMEN

OBJECTIVES: This study compares the genome of an ST131 CMY-2-producing Escherichia coli isolate from a Danish patient with other ST131 CMY-2-producing E. coli isolates of both human and animal origin. METHODS: In 2016, an ST131 CMY-2-producing E. coli isolate (ESBL20160056) was obtained from a patient with a bloodstream infection. The genome of the ESBL20160056 isolate was compared with genomes from six ST131 CMY-2-producing E. coli isolates obtained from broiler meat imported to Denmark, 15 ST131 CMY-2-producing E. coli isolates obtained from Enterobase (http://enterobase.warwick.ac.uk) and two ST131 CMY-2-producing E. coli from European collaborators. The plasmid from ESBL20160056 was sequenced using a MinION Mk1B (Oxford Nanopore Technologies). RESULTS: The E. coli isolate from the Danish patient clustered together with 13 other fimH22 ST131 CMY-2-producing E. coli isolates in a distinct clade. The clade consisted of genomes from six E. coli isolates from humans collected in Denmark, Spain, Cambodia and the USA, six E. coli isolates obtained from broiler meat samples imported to Denmark from France, the Netherlands and Germany, and two E. coli isolates obtained from broilers in Belgium and Luxembourg. The 101.5 kb plasmid with blaCMY-2 from ESBL20160056 had an IncI1 replicon and belonged to ST12 using the plasmid MLST scheme. In total, 10 of the 14 ST131 E. coli isolates belonging to the fimH22 clade carried an IncI1 ST12 plasmid with blaCMY-2. CONCLUSIONS: From our data, it seems plausible that the ST131 fimH22 CMY-2-producing E. coli isolate obtained from the Danish patient could have a zoonotic broiler origin.


Asunto(s)
Bacteriemia/microbiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/enzimología , Genoma Bacteriano , Plásmidos/análisis , beta-Lactamasas/genética , Anciano , Animales , Pollos , Dinamarca , Escherichia coli/clasificación , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Humanos , Carne/microbiología , Homología de Secuencia , beta-Lactamasas/metabolismo
9.
J Antimicrob Chemother ; 73(10): 2738-2747, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30053113

RESUMEN

Objectives: To examine performance of EUCAST disc diffusion and supplementary MIC methods for detection of Enterobacteriaceae with reduced susceptibility to meropenem using EUCAST screening recommendations. Methods: Sixty-one Nordic laboratories delivered data on EUCAST disc diffusion (n = 61), semi-automated meropenem MIC (n = 23; VITEK2, n = 20 and Phoenix, n = 3) and gradient meropenem MIC (n = 58) methods. The strains (n = 27) included the major carbapenemase classes (A, n = 4; B, n = 9; D, n = 6) involved in the global spread of carbapenemase-producing Enterobacteriaceae (CPE) and non-CPE strains (n = 8) covering a range of broth microdilution (BMD) meropenem MICs. Results: A triplicate Klebsiella variicola (meropenem MIC 0.5 mg/L) harbouring OXA-48 and Escherichia coli ATCC 25922 showed an overall good precision. Meropenem zone diameters below the EUCAST screening cut-off (<27 mm) were reported for strains with MIC ≥1 mg/L (n = 21), irrespective of resistance mechanism. For three strains (MIC = 0.5 mg/L) with OXA-48/-181, eight laboratories provided meropenem zone diameters above the screening cut-off. Very major errors (VMEs) were not observed. The overall distributions of major errors (MEs) and minor errors (mEs) were 9% and 36% (disc diffusion), 26% and 18% (VITEK2) and 7% and 20% (gradient MIC), respectively. Differences in ME and mE distributions between disc diffusion and MIC gradient tests compared with semi-automated methods were significant (P < 0.0001), using BMD MICs as a reference for categorization. Conclusions: The EUCAST disc diffusion method is a robust method to screen for CPE but isolates with meropenem MICs <1 mg/L pose challenges. The high ME rate in semi-automated methods might deter appropriate use of carbapenems in CPE infections with limited therapeutic options.


Asunto(s)
Antibacterianos/farmacología , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Pruebas Antimicrobianas de Difusión por Disco/normas , Enterobacteriaceae/efectos de los fármacos , Meropenem/farmacología , Pruebas de Sensibilidad Microbiana/normas , Proteínas Bacterianas , Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Carbapenémicos/farmacología , Técnicas de Laboratorio Clínico/estadística & datos numéricos , Enterobacteriaceae/aislamiento & purificación , Escherichia coli/efectos de los fármacos , Humanos , Klebsiella/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , beta-Lactamasas
10.
mSphere ; 3(4)2018 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-30021879

RESUMEN

Escherichia coli sequence type 410 (ST410) has been reported worldwide as an extraintestinal pathogen associated with resistance to fluoroquinolones, third-generation cephalosporins, and carbapenems. In the present study, we investigated national epidemiology of ST410 E. coli isolates from Danish patients. Furthermore, E. coli ST410 was investigated in a global context to provide further insight into the acquisition of the carbapenemase genes blaOXA-181 and blaNDM-5 of this successful lineage. From 127 whole-genome-sequenced isolates, we reconstructed an evolutionary framework of E. coli ST410 which portrays the antimicrobial-resistant clades B2/H24R, B3/H24Rx, and B4/H24RxC. The B2/H24R and B3/H24Rx clades emerged around 1987, concurrently with the C1/H30R and C2/H30Rx clades in E. coli ST131. B3/H24Rx appears to have evolved by the acquisition of the extended-spectrum ß-lactamase (ESBL)-encoding gene blaCTX-M-15 and an IncFII plasmid, encoding IncFIA and IncFIB. Around 2003, the carbapenem-resistant clade B4/H24RxC emerged when ST410 acquired an IncX3 plasmid carrying a blaOXA-181 carbapenemase gene. Around 2014, the clade B4/H24RxC acquired a second carbapenemase gene, blaNDM-5, on a conserved IncFII plasmid. From an epidemiological investigation of 49 E. coli ST410 isolates from Danish patients, we identified five possible regional outbreaks, of which one outbreak involved nine patients with blaOXA-181- and blaNDM-5-carrying B4/H24RxC isolates. The accumulated multidrug resistance in E. coli ST410 over the past two decades, together with its proven potential of transmission between patients, poses a high risk in clinical settings, and thus, E. coli ST410 should be considered a lineage with emerging "high-risk" clones, which should be monitored closely in the future.IMPORTANCE Extraintestinal pathogenic Escherichia coli (ExPEC) is the main cause of urinary tract infections and septicemia. Significant attention has been given to the ExPEC sequence type ST131, which has been categorized as a "high-risk" clone. High-risk clones are globally distributed clones associated with various antimicrobial resistance determinants, ease of transmission, persistence in hosts, and effective transmission between hosts. The high-risk clones have enhanced pathogenicity and cause severe and/or recurrent infections. We show that clones of the E. coli ST410 lineage persist and/or cause recurrent infections in humans, including bloodstream infections. We found evidence of ST410 being a highly resistant globally distributed lineage, capable of patient-to-patient transmission causing hospital outbreaks. Our analysis suggests that the ST410 lineage should be classified with the potential to cause new high-risk clones. Thus, with the clonal expansion over the past decades and increased antimicrobial resistance to last-resort treatment options, ST410 needs to be monitored prospectively.


Asunto(s)
Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Evolución Molecular , Escherichia coli Patógena Extraintestinal/genética , Escherichia coli Patógena Extraintestinal/aislamiento & purificación , Genotipo , Proteínas Bacterianas/genética , Dinamarca/epidemiología , Brotes de Enfermedades , Escherichia coli Patógena Extraintestinal/clasificación , Humanos , Tipificación de Secuencias Multilocus , Prevalencia , Estudios Prospectivos , Secuenciación Completa del Genoma , beta-Lactamasas/genética
11.
Sensors (Basel) ; 17(1)2017 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-28075371

RESUMEN

This article is a feasibility study on using fluorescence-based oil-in-water (OiW) monitors for on-line dynamic efficiency measurement of a deoiling hydrocyclone. Dynamic measurements are crucial in the design and validation of dynamic models of the hydrocyclones, and to our knowledge, no dynamic OiW analysis of hydrocyclones has been carried out. Previous studies have extensively studied the steady state efficiency perspective of hydrocyclones, and have related them to different key parameters, such as the pressure drop ratio (PDR), inlet flow rate, and the flow-spilt. Through our study, we were able to measure the dynamics of the hydrocyclone's efficiency ( ϵ ) response to step changes in the inlet flow rate with high accuracy. This is a breakthrough in the modelling, control, and monitoring of hydrocyclones.

12.
Euro Surveill ; 20(49)2015.
Artículo en Inglés | MEDLINE | ID: mdl-26676364

RESUMEN

The plasmid-mediated colistin resistance gene, mcr-1, was detected in an Escherichia coli isolate from a Danish patient with bloodstream infection and in five E. coli isolates from imported chicken meat. One isolate from chicken meat belonged to the epidemic spreading sequence type ST131. In addition to IncI2, an incX4 replicon was found to be linked to mcr-1. This report follows a recent detection of mcr-1 in E. coli from animals, food and humans in China.


Asunto(s)
Antibacterianos/farmacología , Colistina/farmacología , Farmacorresistencia Bacteriana , Infecciones por Escherichia coli/sangre , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Animales , Pollos , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Genotipo , Humanos , Carne/microbiología , Plásmidos
13.
mBio ; 6(4): e00630, 2015 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-26199326

RESUMEN

UNLABELLED: Highly invasive, community-acquired Klebsiella pneumoniae infections have recently emerged, resulting in pyogenic liver abscesses. These infections are caused by hypervirulent K. pneumoniae (hvKP) isolates primarily of capsule serotype K1 or K2. Hypervirulent K1 isolates belong to clonal complex 23 (CC23), indicating that this clonal lineage has a specific genetic background conferring hypervirulence. Here, we apply whole-genome sequencing to a collection of K. pneumoniae isolates to characterize the phylogenetic background of hvKP isolates with an emphasis on CC23. Most of the hvKP isolates belonged to CC23 and grouped into a distinct monophyletic clade, revealing that CC23 is a unique clonal lineage, clearly distinct from nonhypervirulent strains. Separate phylogenetic analyses of the CC23 isolates indicated that the CC23 lineage evolved recently by clonal expansion from a single common ancestor. Limited grouping according to geographical origin was observed, suggesting that CC23 has spread globally through multiple international transmissions. Conversely, hypervirulent K2 strains clustered in genetically unrelated groups. Strikingly, homologues of a large virulence plasmid were detected in all hvKP clonal lineages, indicating a key role in K. pneumoniae hypervirulence. The plasmid encodes two siderophores, aerobactin and salmochelin, and RmpA (regulator of the mucoid phenotype); all these factors were found to be restricted to hvKP isolates. Genomic comparisons revealed additional factors specifically associated with CC23. These included a distinct variant of a genomic island encoding yersiniabactin, colibactin, and microcin E492. Furthermore, additional novel genomic regions unique to CC23 were revealed which may also be involved in the increased virulence of this important clonal lineage. IMPORTANCE: During the last 3 decades, hypervirulent Klebsiella pneumoniae (hvKP) isolates have emerged, causing severe community-acquired infections primarily in the form of pyogenic liver abscesses. This syndrome has so far primarily been found in Southeast Asia, but increasing numbers of cases are being reported worldwide, indicating that the syndrome is turning into a globally emerging disease. We applied whole-genome sequencing to a collection of K. pneumoniae clinical isolates to reveal the phylogenetic background of hvKP and to identify genetic factors associated with the increased virulence. The hvKP isolates primarily belonged to clonal complex 23 (CC23), and this clonal lineage was revealed to be clearly distinct from nonhypervirulent strains. A specific virulence plasmid was found to be associated with hypervirulence, and novel genetic determinants uniquely associated with CC23 were identified. Our findings extend the understanding of the genetic background of the emergence of hvKP clones.


Asunto(s)
Evolución Molecular , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/patogenicidad , Absceso Hepático/epidemiología , Absceso Hepático/microbiología , Proteínas Bacterianas/genética , Bacteriocinas/genética , ADN Bacteriano/química , ADN Bacteriano/genética , Genoma Bacteriano , Islas Genómicas , Genotipo , Salud Global , Humanos , Klebsiella pneumoniae/clasificación , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Epidemiología Molecular , Filogeografía , Plásmidos/análisis , Análisis de Secuencia de ADN , Serogrupo , Virulencia , Factores de Virulencia/genética
14.
J Glob Antimicrob Resist ; 3(2): 132-136, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27873662

RESUMEN

CTX-M-1 is a common extended-spectrum ß-lactamase (ESBL) in Escherichia coli from animals and is often detected among human clinical isolates. The objective of this study was to investigate the epidemiological relationship between CTX-M-1-producing E. coli isolated from patients and animals in Denmark between 2006 and 2010. In total, 65 CTX-M-1-producing isolates from patients (n=22), pigs (n=21), cattle (n=4), organic poultry layers (n=3) and horses (n=15) were typed by pulsed-field gel electrophoresis (PFGE). Plasmids harbouring blaCTX-M-1 were characterised by S1 PFGE, PCR-based replicon typing, plasmid multilocus sequence typing, restriction fragment length polymorphism, and sequencing. Human and animal strains were unrelated based on PFGE. IncI1 was more common in human isolates (13/22) than in animal isolates (7/43), whereas the opposite trend was observed for IncN (5/22 human isolates and 24/43 animal isolates). Full characterisation of the plasmids harbouring blaCTX-M-1 revealed host-specific patterns in the distribution of plasmid types, with specific IncI1, IncN and IncH1 plasmid subtypes being predominant in humans, livestock and horses, respectively. Three indistinguishable human, bovine and porcine IncI1/ST49 plasmids had high nucleotide sequence homology and differed by the presence of IS66 elements in the bovine plasmid and the absence of one gene within the microcin-encoding operon in the human plasmid. In conclusion, this work suggests a minor contribution by animals to the occurrence of CTX-M-1 in human E. coli infections in Denmark during the study period.

16.
Antimicrob Agents Chemother ; 58(11): 6886-95, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25199783

RESUMEN

To identify possible explanations for the recent global emergence of Escherichia coli sequence type (ST) 131 (ST131), we analyzed temporal trends within ST131 O25 for antimicrobial resistance, virulence genes, biofilm formation, and the H30 and H30-Rx subclones. For this, we surveyed the WHO E. coli and Klebsiella Centre's E. coli collection (1957 to 2011) for ST131 isolates, characterized them extensively, and assessed them for temporal trends. Overall, antimicrobial resistance increased temporally in prevalence and extent, due mainly to the recent appearance of the H30 (1997) and H30-Rx (2005) ST131 subclones. In contrast, neither the total virulence gene content nor the prevalence of biofilm production increased temporally, although non-H30 isolates increasingly qualified as extraintestinal pathogenic E. coli (ExPEC). Whereas virotype D occurred from 1968 forward, virotypes A and C occurred only after 2000 and 2002, respectively, in association with the H30 and H30-Rx subclones, which were characterized by multidrug resistance (including extended-spectrum-beta-lactamase [ESBL] production: H30-Rx) and absence of biofilm production. Capsular antigen K100 occurred exclusively among H30-Rx isolates (55% prevalence). Pulsotypes corresponded broadly with subclones and virotypes. Thus, ST131 should be regarded not as a unitary entity but as a group of distinctive subclones, with its increasing antimicrobial resistance having a strong clonal basis, i.e., the emergence of the H30 and H30-Rx ST131 subclones, rather than representing acquisition of resistance by diverse ST131 strains. Distinctive characteristics of the H30-Rx subclone-including specific virulence genes (iutA, afa and dra, kpsII), the K100 capsule, multidrug resistance, and ESBL production-possibly contributed to epidemiologic success, and some (e.g., K100) might serve as vaccine targets.


Asunto(s)
Antígenos Bacterianos/genética , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli , Polisacáridos Bacterianos/genética , Factores de Virulencia/genética , Biopelículas , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/patogenicidad , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Pruebas de Sensibilidad Microbiana , Serogrupo , Toxinas Shiga/biosíntesis , beta-Lactamasas/biosíntesis , beta-Lactamasas/genética
18.
J Clin Microbiol ; 51(6): 1779-85, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23554186

RESUMEN

We report the characteristics of 115 extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli clinical isolates, from 115 unique Danish patients, over a 1-year study interval (1 October 2008 to 30 September 2009). Forty-four (38%) of the ESBL isolates represented sequence type 131 (ST13)1, from phylogenetic group B2. The remaining 71 isolates were from phylogenetic groups D (27%), A (22%), B1 (10%), and B2 (3%). Serogroup O25 ST131 isolates (n = 42; 95% of ST131) comprised 7 different K antigens, whereas two ST131 isolates were O16:K100:H5. Compared to non-ST131 isolates, ST131 isolates were associated positively with CTX-M-15 and negatively with CTX-M-1 and CTX-M-14. They also were associated positively with 11 virulence genes, including afa and dra (Dr family adhesins), the F10 papA allele (P fimbria variant), fimH (type 1 fimbriae), fyuA (yersiniabactin receptor), iha (adhesin siderophore), iutA (aerobactin receptor), kpsM II (group 2 capsules), malX (pathogenicity island marker), ompT (outer membrane protease), sat (secreted autotransporter toxin), and usp (uropathogenicity-specific protein) and negatively with hra (heat-resistant agglutinin) and iroN (salmochelin receptor). The consensus virulence gene profile (>90% prevalence) of the ST131 isolates included fimH, fyuA, malX, and usp (100% each), ompT and the F10 papA allele (95% each), and kpsM II and iutA (93% each). ST131 isolates were also positively associated with community acquisition, extraintestinal pathogenic E. coli (ExPEC) status, and the O25, K100, and H4 antigens. Thus, among ESBL E. coli isolates in Copenhagen, ST131 was the most prevalent clonal group, was community associated, and exhibited distinctive and comparatively extensive virulence profiles, plus a greater variety of capsular antigens than reported previously.


Asunto(s)
Epidemias , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Escherichia coli/clasificación , Escherichia coli/genética , beta-Lactamasas/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Dinamarca/epidemiología , Escherichia coli/enzimología , Escherichia coli/aislamiento & purificación , Femenino , Genotipo , Humanos , Lactante , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Prevalencia , Serotipificación , Factores de Virulencia/genética , Adulto Joven
20.
J Clin Microbiol ; 50(11): 3703-11, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22972830

RESUMEN

In 1991, multiresistant Escherichia coli O78:H10 strains caused an outbreak of urinary tract infections in Copenhagen, Denmark. The phylogenetic origin, clonal background, and virulence characteristics of the outbreak isolates, and their relationship to nonoutbreak O78:H10 strains according to these traits and resistance profiles, are unknown. Accordingly, we extensively characterized 51 archived E. coli O78:H10 isolates (48 human isolates from seven countries, including 19 Copenhagen outbreak isolates, and 1 each of calf, avian, and unknown-source isolates), collected from 1956 through 2000. E. coli O78:H10 was clonally heterogeneous, comprising one dominant clonal group (61% of isolates, including all 19 outbreak isolates) from ST10 (phylogenetic group A) plus several minor clonal groups (phylogenetic groups A and D). All ST10 isolates, versus 25% of non-ST10 isolates, were identified by molecular methods as enteroaggregative E. coli (EAEC) (P < 0.001). Genes present in >90% of outbreak isolates included fimH (type 1 fimbriae; ubiquitous in E. coli); fyuA, traT, and iutA (associated with extraintestinal pathogenic E. coli [ExPEC]); and sat, pic, aatA, aggR, aggA, ORF61, aaiC, aap, and ORF3 (associated with EAEC). An outbreak isolate was lethal in a murine subcutaneous sepsis model and exhibited characteristic EAEC "stacked brick" adherence to cultured epithelial cells. Thus, the 1991 Copenhagen outbreak was caused by a tight, non-animal-associated subset within a broadly disseminated O78:H10 clonal group (ST10; phylogenetic group A), members of which exhibit both ExPEC and EAEC characteristics, whereas O78:H10 isolates overall are phylogenetically diverse. Whether ST10 O78:H10 EAEC strains are both uropathogenic and diarrheagenic warrants further investigation.


Asunto(s)
Brotes de Enfermedades , Infecciones por Escherichia coli/epidemiología , Escherichia coli/clasificación , Escherichia coli/genética , Tipificación Molecular , Infecciones Urinarias/epidemiología , Animales , Niño , Análisis por Conglomerados , Dinamarca/epidemiología , Modelos Animales de Enfermedad , Farmacorresistencia Bacteriana Múltiple , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Variación Genética , Genotipo , Humanos , Recién Nacido , Ratones , Epidemiología Molecular , Filogenia , Sepsis/mortalidad , Serotipificación , Análisis de Supervivencia , Infecciones Urinarias/microbiología
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