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Dive into the research topics where Esther Kuenzli is active.

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Featured researches published by Esther Kuenzli.


BMC Infectious Diseases | 2014

High colonization rates of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Swiss Travellers to South Asia– a prospective observational multicentre cohort study looking at epidemiology, microbiology and risk factors

Esther Kuenzli; Veronika K. Jaeger; Reno Frei; Andreas Neumayr; Susan DeCrom; Sabine Haller; Johannes Blum; Andreas F. Widmer; Hansjakob Furrer; Manuel Battegay; Andrea Endimiani; Christoph Hatz

BackgroundInternational travel contributes to the worldwide spread of multidrug resistant Gram-negative bacteria. Rates of travel-related faecal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae vary for different destinations. Especially travellers returning from the Indian subcontinent show high colonization rates. So far, nothing is known about region-specific risk factors for becoming colonized.MethodsAn observational prospective multicentre cohort study investigated travellers to South Asia. Before and after travelling, rectal swabs were screened for third-generation cephalosporin- and carbapenem-resistant Enterobacteriaceae. Participants completed questionnaires to identify risk factors for becoming colonized. Covariates were assessed univariately, followed by a multivariate regression.ResultsHundred and seventy persons were enrolled, the largest data set on travellers to the Indian subcontinent so far. The acquired colonization rate with ESBL-producing Escherichia coli overall was 69.4% (95% CI 62.1-75.9%), being highest in travellers returning from India (86.8%; 95% CI 78.5-95.0%) and lowest in travellers returning from Sri Lanka (34.7%; 95% CI 22.9-48.7%). Associated risk factors were travel destination, length of stay, visiting friends and relatives, and eating ice cream and pastry.ConclusionsHigh colonization rates with ESBL-producing Enterobacteriaceae were found in travellers returning from South Asia. Though risk factors were identified, a more common source, i.e. environmental, appears to better explain the high colonization rates.


Antimicrobial Agents and Chemotherapy | 2016

Travelers Can Import Colistin-Resistant Enterobacteriaceae, Including Those Possessing the Plasmid-Mediated mcr-1 Gene

Odette Joëlle Bernasconi; Esther Kuenzli; João Pires; Regula Tinguely; Alessandra Carattoli; Christoph Hatz; Vincent Perreten; Andrea Endimiani

ABSTRACT Stool samples from 38 travelers returning from India were screened for extended-spectrum cephalosporin- and carbapenem-resistant Enterobacteriaceae implementing standard selective plates. Twenty-six (76.3%) people were colonized with CTX-M or DHA producers, but none of the strains was colistin resistant and/or mcr-1 positive. Nevertheless, using overnight enrichment and CHROMagar Orientation plates supplemented with colistin, four people (10.5%) were found to be colonized with colistin-resistant Escherichia coli. One cephalosporin-susceptible sequence type 10 (ST10) strain carried a 4,211-bp ISApl1-mcr-1-ISApl1 element in an IncHI2 plasmid backbone.


The Journal of Infectious Diseases | 2015

Immune Reconstitution After Allogeneic Hematopoietic Stem Cell Transplantation and Association With Occurrence and Outcome of Invasive Aspergillosis

Claudia Stuehler; Esther Kuenzli; Veronika K. Jaeger; Veronika Baettig; Fabrizia Ferracin; Zarko Rajacic; Deborah Kaiser; Claudia Bernardini; Pascal Forrer; Maja Weisser; Luigia Elzi; Manuel Battegay; Joerg Halter; Jakob Passweg; Nina Khanna

BACKGROUND Invasive aspergillosis (IA) remains a leading cause of morbidity and mortality in patients receiving allogeneic hematopoietic stem cell transplantation (HSCT). To date, no reliable immunological biomarkers for management and outcome of IA exist. Here, we investigated reconstitution of antifungal immunity in patients during the first 12 months after HSCT and correlated it with IA. METHODS Fifty-one patients were included, 9 with probable/proven IA. We determined quantitative and qualitative reconstitution of polymorphonuclear (PMN), CD4, CD8, and natural killer (NK) cells against Aspergillus fumigatus over 5 time points and compared the values to healthy donors. RESULTS Absolute CD4 and CD8 cell counts, antigen-specific T-cell responses, and killing capacity of PMN against A. fumigatus were significantly decreased in all patients over 12 months. In patients with probable/proven IA, reactive oxygen species (ROS) production tended to be lower compared to patients without IA, and absolute NK-cell counts remained below 200 cells/µL. Patients with well-controlled IA showed significantly higher ROS production and NK-cell counts compared to patients with poor outcome. CONCLUSIONS This study highlights the importance of functional PMN, T-cell, and NK-cell immunity for the outcome of IA. Larger multicenter studies should address the potential use of NK-cell counts for the management of antifungal therapy.


Frontiers in Microbiology | 2016

Polyclonal Intestinal Colonization with Extended-Spectrum Cephalosporin-Resistant Enterobacteriaceae upon Traveling to India.

João Pires; Esther Kuenzli; Sara Kasraian; Regula Tinguely; Hansjakob Furrer; Christoph Hatz; Andrea Endimiani

We aimed to assess the intestinal colonization dynamics by multiple extended-spectrum cephalosporin-resistant Enterobacteriaceae (ESC-R-Ent) clones in Swiss travelers to India, a country with high prevalence of these multidrug-resistant pathogens. Fifteen healthy volunteers (HVs) colonized with ESC-R-Ent after traveling to India who provided stools before, after, and at 3- and 6-month follow-up are presented in this study. Stools were enriched in a LB broth containing 3 mg/L cefuroxime and plated in standard selective media (BLSE, ChromID ESBL, Supercarba) to detect carbapenem- and/or ESC-R-Ent. At least 5 Enterobacteriaceae colonies were analyzed for each stool provided. All strains underwent phenotypic tests (MICs in microdilution) and molecular typing to define bla genes (microarray, PCR/sequencing), clonality (MLST, rep-PCR), and plasmid content. While only three HVs were colonized before the trip, all participants had positive stools after returning, but the colonization rate decreased during the follow-up period (i.e., six HVs were still colonized at both 3 and 6 months). More importantly, polyclonal acquisition (median of 2 clones, range 1–5) was identified at return in all HVs. The majority of the Escherichia coli isolates belonged to phylogenetic groups A and B1 and to high diverse non-epidemic sequence types (STs); however, 15% of them belonged to clonal complex 10 and mainly possessed blaCTX−M−15 genes. F family plasmids were constantly found (~80%) in the recovered ESC-R-Ent. Our results indicate a possible polyclonal acquisition of the ESC-R-Ent via food-chain and/or through an environmental exposure. For some HVs, prolonged colonization in the follow-up period was observed due to clonal persistence or presence of the same plasmid replicon types in a new bacterial host. Travel medicine practitioners, clinicians, and clinical microbiologists who are facing the returning travelers and their samples for different reasons should be aware of this important phenomenon, so that better infection control measures, treatment strategies, and diagnostic tests can be adopted.


Acta Tropica | 2016

Toxocariasis-associated cardiac diseases--A systematic review of the literature.

Esther Kuenzli; Andreas Neumayr; Matthew Chaney; Johannes Blum

Toxocariasis, caused by Toxocara canis or Toxocara catis, is a worldwide occurring parasitic disease, reaching high prevalences especially in tropical and subtropical countries. The clinical presentation can range from asymptomatic seropositivity to life threatenting disease, depending on the organ system involved. Cardiac involvement, one of the possible manifestations of human Toxocara spp. infection, is rarely reported in case reports. As far as we know, no systematic reviews of clinical presentations have been published till now and no clear recommendations regarding the treatment of Toxocara spp. infection involving the heart exist. In a systematic review of the literature, 24 published cases of Toxocara spp. infection involving the heart were identified. The cardiac entities described included myocarditis, pericarditis, and Loefflers endocarditis. The clinical presentation ranged from asymptomatic or mild disease to life threatening myocarditis/pericarditis with heart failure or cardiac tamponade, leading to death. In most cases, the diagnosis was based on a combination of clinical, laboratory and radiological findings. Only in three of the nine cases in which histological analysis was performed (either pre- or post-mortem), granulomas or remnants of the parasite were detected. In the other six cases, findings were non-specific; the damage of the heart was equally caused by direct invasion of the larvae and by immunological reactions, either caused by the systemic hypereosinophilia or by the presence of the larvae in the tissue. The treatment regimen described mostly consisted of anthelmintic drugs in combination with corticosteroids. Even though dosage and duration of treatment varied widely, ranging from days to months, most patients were treated successfully. Cardiac involvement in Toxocara spp. infection is a rare but potentially life-threatening complication of a very common disease. The therapeutic regimens vary widely especially with regard to the duration of therapy, however, the combination of an anthelmintic drug and a corticosteroid appears to be a valuable option. For the daily clinical work, tissue manifestation by parasites should be considered in cases of unspecific organ manifestations, (i.e. heart, lungs, liver), accompanied by fever and eosinophilia with or without allergic skin rashes.


Travel Medicine and Infectious Disease | 2016

Antibiotic resistance and international travel: Causes and consequences

Esther Kuenzli

The discovery of Penicillin by Alexander Fleming in 1928 is generally considered the beginning of the antibiotic era in medicine. Suddenly, bacterial diseases like pneumonia, septicaemia, gangrene or tuberculosis were no longer an inevitable death sentence. Today, decades of much uncontrolled, unwarranted use of antibiotics in both, human medicine and animal husbandry bring us, according to the WHO, to the brink of a post-antibiotic era [1]. A fate which somehow has already been predicted by Alexander Fleming in 1945: When accepting his Nobel Prize for the discovery of penicillin he said: “There is the danger that the ignorant man may easily underdose himself and by exposing his microbes to nonlethal quantities of the drug make them resistant.”


Infection Control and Hospital Epidemiology | 2013

Additive Effect of Enterococcus faecium on Enterococcal Bloodstream Infections: A 14-Year Study in a Swiss Tertiary Hospital

Maja Weisser; Selja Capaul; Marc Dangel; Luigia Elzi; Esther Kuenzli; Reno Frei; Andreas F. Widmer

We investigated whether an increase in enterococcal bloodstream infections (BSIs) depends on the emergence of Enterococcus faecium in an area with low vancomycin-resistant enterococci prevalence. From 1999 to 2012, a linear increase in E. faecium BSI rates (0.009 per 1,000 patient-days per year; P < .001) was noted. Enterococcus faecalis BSI rates remained stable.


International Journal of Antimicrobial Agents | 2017

Deciphering the Complete Deletion of the MgrB Locus in an Unusual Colistin-Resistant Klebsiella pneumoniae Colonizing the Gut of a Traveler Returning from India

Odette Joëlle Bernasconi; Valentina Donà; João Pires; Esther Kuenzli; Hatz Christoph; Francesco Luzzaro; Vincent Perreten; Andrea Endimiani

most colistin-resistant (Col-R) Klebsiella pneumoniae strains possess alterations of the two-component systems PhoP/Q and PmrA/B. These systems respond to environmental stimuli increasing the expression of the operon pmrHFIJKLM whose products are responsible for lipid A modifications leading to decreased affinity for polymyxins. This process is regulated by a negative feedback of the mgrB gene that encodes for a small protein repressing the PhoP/Q system. Thus, inactivation of mgrB leads to polymyxin resistance.


Open Forum Infectious Diseases | 2016

Staphylococcus aureus Endocarditis as a Complication of Toxocariasis-Associated Endomyocarditis With Fibrosis: A Case Report.

Esther Kuenzli; Niklaus Daniel Labhardt; Gianmarco M. Balestra; Maja Weisser; Michael J. Zellweger; Johannes Blum

Complications associated with Toxocara canis infection are rare. We present a case of a patient with Staphylococcus aureus endocarditis as a complication of an endomyocardial fibrosis caused by T canis. The epidemiological, pathological, and clinical features of this rare complication are described here.


Journal of Travel Medicine | 2017

Previous exposure in a high-risk area for travellers’ diarrhoea within the past year is associated with a significant protective effect for travellers’ diarrhoea: a prospective observational cohort study in travellers to South Asia

Esther Kuenzli; David Juergensen; Kerstin Kling; Veronika K. Jaeger; Susan DeCrom; Robert Steffen; Andreas F. Widmer; Manuel Battegay; Christoph Hatz; Andreas Neumayr

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Christoph Hatz

Swiss Tropical and Public Health Institute

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Maja Weisser

Swiss Tropical and Public Health Institute

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Andreas Neumayr

Swiss Tropical and Public Health Institute

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Johannes Blum

Swiss Tropical and Public Health Institute

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