7 results on '"Alina Meilaender"'
Search Results
2. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae.
- Author
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Mohamed Ramadan El-Jade, Marijo Parcina, Ricarda Maria Schmithausen, Christoph Stein, Alina Meilaender, Achim Hoerauf, Ernst Molitor, and Isabelle Bekeredjian-Ding
- Subjects
Medicine ,Science - Abstract
Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen.
- Published
- 2016
- Full Text
- View/download PDF
3. Analysis of Transmission of MRSA and ESBL-E among Pigs and Farm Personnel.
- Author
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Ricarda Maria Schmithausen, Sophia Veronika Schulze-Geisthoevel, Franziska Stemmer, Mohamed El-Jade, Marion Reif, Sylvia Hack, Alina Meilaender, Gabriele Montabauer, Rolf Fimmers, Marijo Parcina, Achim Hoerauf, Martin Exner, Brigitte Petersen, Gabriele Bierbaum, and Isabelle Bekeredjian-Ding
- Subjects
Medicine ,Science - Abstract
Livestock-associated bacteria with resistance to two or more antibiotic drug classes have heightened our awareness for the consequences of antibiotic consumption and spread of resistant bacterial strains in the veterinary field. In this study we assessed the prevalence of concomitant colonization with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) and enterobacteriaceae expressing extended-spectrum betalactamases (ESBL-E) in farms at the German-Dutch border region. Nasal colonization of pigs with MRSA (113/547 (20.7%)) was less frequent than rectal colonization with ESBL-E (163/540 (30.2%)). On the individual farm level MRSA correlated with ESBL-E recovery. The data further provide information on prevalence at different stages of pig production, including abattoirs, as well as in air samples and humans living and working on the farms. Notably, MRSA was detected in stable air samples of 34 out of 35 pig farms, highlighting air as an important MRSA transmission reservoir. The majority of MRSA isolates, including those from humans, displayed tetracycline resistance and spa types t011 and t034 characteristic for LA-MRSA, demonstrating transmission from pigs to humans. ESBL-E positive air samples were detected on 6 out of 35 farms but no pig-to-human transmission was found. Detection of ESBL-E, e.g. mostly Escherichia coli with CTX-M-type ESBL, was limited to these six farms. Molecular typing revealed transmission of ESBL-E within the pig compartments; however, related strains were also found on unrelated farms. Although our data suggest that acquisition of MRSA and ESBL-E might occur among pigs in the abattoirs, MRSA and ESBL-E were not detected on the carcasses. Altogether, our data define stable air (MRSA), pig compartments (ESBL-E) and abattoir waiting areas (MRSA and ESBL-E) as major hot spots for transmission of MRSA and/or ESBL-E along the pig production chain.
- Published
- 2015
- Full Text
- View/download PDF
4. Heterogeneity of host TLR2 stimulation by Staphylocoocus aureus isolates.
- Author
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Dina Hilmi, Marijo Parcina, Daniel Stollewerk, Jenny Ostrop, Michaele Josten, Alina Meilaender, Ulrich Zaehringer, Thomas A Wichelhaus, Gabriele Bierbaum, Klaus Heeg, Christiane Wolz, and Isabelle Bekeredjian-Ding
- Subjects
Medicine ,Science - Abstract
High lipoprotein expression and potent activation of host Toll-like receptor-2 (TLR2) are characteristic features of the staphylococcal species. Expression of TLR2 in the host is important for clearance of Staphylococcus aureus infection and host survival. Thus, we hypothesized that bacterial regulation of its intrinsic TLR2-stimulatory capacity could represent a means for immune evasion or host adaptation. We, therefore, compared clinical S. aureus isolates in regards to their TLR2 activation potential and assessed the bacterial factors that modulate TLR2-mediated recognition. S. aureus isolates displayed considerable variability in TLR2-activity with low to absent TLR2-activity in 64% of the isolates tested (68/106). Notably, strain-specific TLR2-activity was independent of the strain origin, e.g. no differences were found between strains isolated from respiratory specimen from cystic fibrosis patients or those isolated from invasive disease specimen. TLR2-activity correlated with protein A expression but not with the agr status. Capsule expression and small colony variant formation had a negative impact on TLR2-activity but any disruption of cell wall integrity enhanced TLR2 activation. Altogether, heterogeneity in host TLR2-activity reflects differences in metabolic activity and cell wall synthesis and/or remodeling.
- Published
- 2014
- Full Text
- View/download PDF
5. Rapid monitoring of vancomycin-resistant Enterococcus faecium in hospital departments by repetitive element palindromic polymerase chain reaction
- Author
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Isabelle Bekeredjian-Ding, Martin Exner, Alina Meilaender, J. Uebele, S. Engelhart, Ernst Molitor, Mike Gajdiss, F. Froeschen, Gabriele Bierbaum, and Achim Hoerauf
- Subjects
0301 basic medicine ,Microbiology (medical) ,DNA, Bacterial ,medicine.medical_specialty ,030106 microbiology ,Enterococcus faecium ,Hospital Departments ,Polymerase Chain Reaction ,Repetitive Element ,law.invention ,Vancomycin-Resistant Enterococci ,03 medical and health sciences ,Molecular typing ,Spatio-Temporal Analysis ,law ,Internal medicine ,Epidemiology ,medicine ,Humans ,Typing ,Genotyping ,Polymerase chain reaction ,Gram-Positive Bacterial Infections ,Repetitive Sequences, Nucleic Acid ,Retrospective Studies ,Cross Infection ,Molecular Epidemiology ,biology ,business.industry ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,bacterial infections and mycoses ,biology.organism_classification ,Molecular Typing ,Infectious Diseases ,Epidemiological Monitoring ,Multilocus sequence typing ,business - Abstract
Summary Background The current increase in nosocomial infections caused by vancomycin-resistant enterococci (VRE) warrants improvement of detection methods and hygiene measures. Knowledge of the local epidemiology is important for monitoring compliance of medical personnel with hygiene measures. Aim To evaluate semi-automated repetitive element palindromic polymerase chain reaction (rep-PCR) for rapid molecular typing of VRE. Methods Primary VRE isolates were collected during an observation period of one year and retrospectively typed by rep-PCR. Molecular typing was performed on isolates from two departments with elevated VRE rates and patients with increased risk for systemic VRE infections. Typing results were correlated with temporal and spatial information on patient moves, VRE laboratory results and multi-locus sequence typing (MLST). Findings Approximately 70% of VRE isolates within a department could be assigned to similarity clusters. Spread of VRE was limited to the individual departments. There was no evidence for spread of endemic VRE strains within the geographical catchment area of the hospital. Our results demonstrate the utility of rep-PCR typing on a department level. However, a Diversilab® threshold of ≥98% had to be applied to claim similarity, and suspected transmissions needed to be confirmed by vanA/B genotyping and compiled information on spatial and temporal patient contact. MLST verified the findings. Conclusion Spread of predominantly detected vancomycin-resistant Enterococcus faecium was limited to the department level with no evidence for wider dissemination within the hospital. Well-standardized and validated (semi-)automated rep-PCR systems are useful for rapid detection of possible VRE transmission. However, suspected transmissions need to be confirmed by clinical and microbiological parameters.
- Published
- 2017
6. Heterogeneity of host TLR2 stimulation by Staphylocoocus aureus isolates
- Author
-
Jenny Ostrop, Daniel Stollewerk, Alina Meilaender, Michaele Josten, Isabelle Bekeredjian-Ding, Thomas A. Wichelhaus, Marijo Parcina, Dina Hilmi, Christiane Wolz, Klaus Heeg, Ulrich Zaehringer, and Gabriele Bierbaum
- Subjects
Bacterial Diseases ,Staphylococcus aureus ,medicine.drug_class ,Lipoproteins ,Staphylococcus ,Antibiotics ,Immunology ,lcsh:Medicine ,Pathogenesis ,Biology ,medicine.disease_cause ,Pathology and Laboratory Medicine ,Cystic fibrosis ,Microbiology ,Immune system ,Cell Wall ,medicine ,Medicine and Health Sciences ,Humans ,ddc:610 ,lcsh:Science ,Microbial Pathogens ,Innate Immune System ,Multidisciplinary ,Host (biology) ,lcsh:R ,Immunity ,Biology and Life Sciences ,Staphylococcal Infections ,medicine.disease ,Immunity, Innate ,Toll-Like Receptor 2 ,Bacterial Pathogens ,TLR2 ,HEK293 Cells ,Infectious Diseases ,Medical Microbiology ,Immune System ,Host-Pathogen Interactions ,biology.protein ,lcsh:Q ,Host adaptation ,Protein A ,Research Article - Abstract
High lipoprotein expression and potent activation of host Toll-like receptor-2 (TLR2) are characteristic features of the staphylococcal species. Expression of TLR2 in the host is important for clearance of Staphylococcus aureus infection and host survival. Thus, we hypothesized that bacterial regulation of its intrinsic TLR2-stimulatory capacity could represent a means for immune evasion or host adaptation. We, therefore, compared clinical S. aureus isolates in regards to their TLR2 activation potential and assessed the bacterial factors that modulate TLR2-mediated recognition. S. aureus isolates displayed considerable variability in TLR2-activity with low to absent TLR2-activity in 64% of the isolates tested (68/106). Notably, strain-specific TLR2-activity was independent of the strain origin, e.g. no differences were found between strains isolated from respiratory specimen from cystic fibrosis patients or those isolated from invasive disease specimen. TLR2-activity correlated with protein A expression but not with the agr status. Capsule expression and small colony variant formation had a negative impact on TLR2-activity but any disruption of cell wall integrity enhanced TLR2 activation. Altogether, heterogeneity in host TLR2-activity reflects differences in metabolic activity and cell wall synthesis and/or remodeling.
- Published
- 2013
7. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae
- Author
-
Ernst Molitor, Achim Hoerauf, Mohamed Ramadan El-Jade, Marijo Parcina, Alina Meilaender, Isabelle Bekeredjian-Ding, Ricarda Maria Schmithausen, and Christoph Stein
- Subjects
0301 basic medicine ,Klebsiella ,Cefotaxime ,Swine ,Klebsiella pneumoniae ,lcsh:Medicine ,Ceftazidime ,Pathology and Laboratory Medicine ,Cefpodoxime ,Klebsiella Pneumoniae ,Antibiotics ,Medicine and Health Sciences ,polycyclic compounds ,lcsh:Science ,Mammals ,Multidisciplinary ,biology ,Antimicrobials ,Drugs ,Agriculture ,Veterinary Diagnostics ,Bacterial Pathogens ,Medical Microbiology ,Vertebrates ,Pathogens ,Research Article ,medicine.drug ,Veterinary Medicine ,Livestock ,Bacterial Disk Diffusion ,030106 microbiology ,Enterobacter ,Microbiology ,Tazobactam ,Antibiotic Susceptibility Testing ,03 medical and health sciences ,Enterobacteriaceae ,Microbial Control ,medicine ,Animals ,Microbial Pathogens ,Etest ,Pharmacology ,Bacteria ,lcsh:R ,Organisms ,Biology and Life Sciences ,biochemical phenomena, metabolism, and nutrition ,bacterial infections and mycoses ,biology.organism_classification ,Pharmacologic Analysis ,Amniotes ,bacteria ,lcsh:Q ,Veterinary Science ,Piperacillin - Abstract
Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen.
- Published
- 2016
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