Norbert Lehn

Universität Regensburg, Ratisbon, Bavaria, Germany

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Publications (183)884.47 Total impact


  • No preview · Article · Aug 2015 · Zeitschrift für Gastroenterologie
  • W. Baer · P. Schaller · S. Ruf · N. Lehn · K. Lerch
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    ABSTRACT: Necrotizing fasciitis is a soft tissue infection with a lethality ranging up to 80%. Infection causes the activation of interleukin, tumor necrosis factor alpha, and gamma-interferon through a triggering mechanism. This results in a capillary thrombosis with necrosis of the fascia, cutis, and subcutis. The patient's history often reveals a triggering event in the form of a recent minimal trauma or operative procedure. In a fulminant necrotizing fasciitis, the development of sepsis with consecutive multiple-organ failure mainly determines the outcome of the disease. Diagnosis is made initially upon clinical findings with a rapid progression of the disease and confirmed later by histologic and microbiologic findings. Radical surgical debridement within the first 24 h with postoperative treatment in an intensive care unit represents the cornerstone of therapy. Between January 1992 and March 2001, we treated 15 patients with necrotizing fasciitis. Lethality was 33%. There was a significant correlation between risk factors (present in 86% of the patients) and morbidity. Diagnosis and therapy should be performed by an experienced surgeon. In this contribution, we discuss the most important criteria that lead to the diagnosis and the therapeutic consequences.
    No preview · Article · Jun 2014 · Der Orthopäde
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    ABSTRACT: Colonization by Helicobacter species is commonly noted in many mammals. These infections often remain unrecognized, but can cause severe health complications or more subtle host immune perturbations. The aim of this study was to isolate and characterize putative novel Helicobacter spp. from Bengal tigers in Thailand. Morphological investigation (Gram-staining and electron microscopy) and genetic studies (16SrRNA, 23SrRNA, flagellin, urease and prophage gene analyses, RAPD DNA fingerprinting and restriction fragment polymorphisms) as well as Western blotting were used to characterize the isolated Helicobacters. Electron microscopy revealed spiral-shaped bacteria, which varied in length (2.5–6 mm) and contained up to four monopolar sheathed flagella. The 16SrRNA, 23SrRNA, sequencing and protein expression analyses identified novel H. acinonychis isolates closely related to H. pylori. These Asian isolates are genetically very similar to H. acinonychis strains of other big cats (cheetahs, lions, lion-tiger hybrid and other tigers) from North America and Europe, which is remarkable in the context of the great genetic diversity among worldwide H. pylori strains. We also found by immunoblotting that the Bengal tiger isolates express UreaseA/B, flagellin, BabA adhesin, neutrophil-activating protein NapA, HtrA protease, c-glutamyl-transpeptidase GGT, Slt lytic transglycosylase and two DNA transfer relaxase orthologs that were known from H. pylori, but not the cag pathogenicity island, nor CagA, VacA, SabA, DupA or OipA proteins. These results give fresh insights into H. acinonychis genetics and the expression of potential pathogenicity-associated factors and their possible pathophysiological relevance in related gastric infections.
    Full-text · Article · Jan 2013 · PLoS ONE
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    ABSTRACT: Background Recently, increasing antibiotic resistance has been observed among gram-positive bacteria. However, only few isolates were found to be resistant against glycopeptides. Therefore, internationally accepted guidelines recommend a restricted use of vancomycin and other glycopeptide antibiotics in order to prevent the development of resistance against these clinically important antibiotics. In many countries, the hospital pharmacies play a key role in control and reinforcement of antibiotic formulary restrictions. In Germany, however, the hospital pharmacies usually do not take over such control functions, and most wards keep a stock of regularly used drugs including antibiotics, which makes reinforcement of restrictions difficult. □ Methods In an attempt to achieve a restriction of vancomycin use, the pharmacy of our university hospital was advised to deliver vancomycin to the wards only on request with a special order form signed by an attending, individually for every patient who should receive vancomycin. The efficacy of this restriction measure was evaluated in 3-month periods before and after the restriction became effective. □ Results Hospitalwide, this led to a 20.1% reduction of i. v. vancomycin and an 85.7% reduction of oral vancomycin use per 1000 patient days. If the hematology/oncology units were not considered, the reduction of i. v. vancomycin use was 41.8%, and the total use after the restriction 24.2 g per 1000 patient days. Microbiology results which justified the use of vancomycin decreased by 8.3% (10.9% hematology/oncology units not considered) between the 2 observation periods. Assuming a 7-day mean course of i. v. vancomycin therapy, the empirical use of i. v. vancomycin decreased from 39.9% to 8% after the restriction had been instituted. □ Conclusion Allowing only experienced physicians (attendings) to decide on the use of vancomycin therapy, proved in our experience to be an effective measure to reduce unnecessary vancomycin use.
    No preview · Article · Apr 2012 · Medizinische Klinik - Intensivmedizin und Notfallmedizin
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    ABSTRACT: Triple therapy with a proton pump inhibitor, moxifloxacin, and amoxicillin has been proven effective in first-line treatment of Helicobacter pylori infection. To explore 1, the value of triple therapy with esomeprazole, moxifloxacin, and amoxicillin in second-line or rescue treatment of Caucasian patients and 2, the impact of treatment duration on eradication success. H. pylori-infected patients with at least one previous treatment failure were randomized to oral esomeprazole 20 mg b.i.d., moxifloxacin 400 mg o.d., and amoxicillin 1000 mg b.i.d. for either 7 (EMA-7) or 14 days (EMA-14). Eradication was confirmed by 13C urea breath test. Antimicrobial susceptibility testing was performed in all patients at baseline and in patients who failed treatment. Eighty patients were randomized, and 60% had ≥ 2 previous treatment failures. Pretreatment resistance against clarithromycin and metronidazole was found in 70.5 and 61.5% of cases, respectively. The intention-to-treat eradication rate was significantly higher after EMA-14 compared with EMA-7 (95.0 vs 78.9%, p = .036). No independent risk factor for treatment failure could be identified. There were no serious adverse events. Five of the EMA-14 patients (12.5%) compared with none of the EMA-7 patients discontinued prematurely because of adverse events (p = .031). Post-treatment resistance against moxifloxacin was found in one of seven patients with isolated organisms (14.3%). Second-line/rescue H. pylori eradication therapy with esomeprazole, moxifloxacin, and amoxicillin is very effective and well tolerated. Fourteen days of treatment significantly increase the eradication rate but also the rate of adverse events.
    No preview · Article · Dec 2011 · Helicobacter

  • No preview · Article · Aug 2011 · Zeitschrift für Gastroenterologie

  • No preview · Article · Aug 2011 · Zeitschrift für Gastroenterologie
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    ABSTRACT: Microbial contamination of whole human saliva is unwanted for certain in vitro applications, e.g., when utilizing it as a growth substratum for biofilm experiments. The aim of this investigation was to test gamma irradiation for its suitability to sterilize saliva and to investigate the treatment's influence on the composition and integrity of salivary proteins in comparison to filter sterilization. For inhibition of bacterial growth by gamma irradiation, a sterility assurance level of 10−6 was determined to be reached at a dose of 3.5 kGy. At this dose, the integrity of proteins, as measured by fluorescence, circular dichroism, and gel electrophoretic banding pattern, and the enzymatic activities of salivary amylase and lysozyme were virtually unchanged. Filtration reduced the total protein concentration to about half of its original value and decreased lysozyme activity to about 10%. It can be concluded that irradiation is suitable for sterilizing whole saliva in its native form.
    Full-text · Article · Feb 2011 · Applied and Environmental Microbiology

  • No preview · Article · Jan 2011 · Gastroenterology

  • No preview · Article · Nov 2008 · Aktuelle Urologie
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    ABSTRACT: Background: We previously demonstrated Moxifloxacin (MXF) + RIF to be equivalent to Vancomycin (VAN) + RIF for treatment of Sa IAO in a rat model. Efficacy of Flucloxacillin (F) and F + RIF were now assessed with the same model, and compared to placebo and (data previously reported) MXF + RIF, VAN + RIF, VAN and MXF. Methods: IAO of the hind leg femur was surgically induced in 68 male Wistar rats: 107 colony forming units (cfu) of methicillin-sensitive Sa strain ATCC 29213 were inoculated into the medullary cavity and a steel implant was inserted. After 7 days, rats were randomised to intraperitoneal administration of placebo, F 200 mg/kg t.i.d., RIF 20 mg/kg, F + RIF, MXF 10 mg/kg b.i.d., MXF + RIF, VAN 60 mg/kg b.i.d. or VAN + RIF. After 14 days of treatment, periprosthetic femur, capsular soft tissue of knee joint, muscle and implant were aseptically explanted and cultured quantitatively. Differences in remaining bacterial burden were analysed by Kruskal-Wallis and Wilcoxon post-hoc (with Holmes correction) test. Results: See table. Significant differences (p<0.05) to F + RIF (#) are shown. RIF-combination therapies performed equally. Median remaining Sa [interquartile range] Placebo N = 12 F N = 10 F+RIF N = 9 MXF N = 9 MXF+RIF N = 10 VAN N= 10 VAN+RIF N = 8 Femur (log10 cfu/g) 4.86# [3.54-5.30] 3.79# [3.31-4.84] 0 $ [0-0] 3.09# [2.8-3.39] 0 $ [0-0] 2.79# [2.64-4.67] 0 $ [0-2.2] Soft tissue (log10 cfu/g) 4.41# [3.86-5.44] 4.42# [4.17-5.00] 0 $ [0-0] 2.83 [0-3.48] 0 $ [0-2.82] 3.85# [3.46-5.41] 2.78 [0-4.23] Muscle (log10 cfu/g) 3.70# [3.41-4.75] 3.71# [2.10-4.39] 0 $ [0-0] n.d. n.d. n.d. n.d. Implant (log10 cfu/ implant) 3.69# [3.22-4.17] 0 $ [0-2.48] 0 $ [0-0] 2.15 [1.3-2.54] 0 $ [0-0] 3.06# [2.92-4.86] 0 $ [0-1.78] $ Detection limit: 20 cfu/ml; n.d.: not done Conclusion: RIF-combination therapies with F, MXF or VAN were equivalent and more efficacious than either monotherapy. Those findings reemphasize the superiority of RIF over F, MXF and VAN in the treatment of Sa IAO. MXF might be an attractive combination partner due to excellent oral bioavailability.
    No preview · Conference Paper · Oct 2008
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    ABSTRACT: The oral cavity has been suspected as an extra-gastroduodenal reservoir for Helicobacter pylori infection and transmission, but conflicting evidence exists regarding the occurrence of H. pylori in the mouth, independently of stomach colonization. Ninety-four gastric biopsy patients were analysed for the concurrent presence of H. pylori in the mouth and stomach. Samples were collected from different areas within the mouth and H. pylori DNA was amplified by the polymerase chain reaction (PCR) and verified by sequencing. Helicobacter pylori-specific serology was performed, and stomach colonization was determined by culture. In addition, relevant dental and periodontal parameters, as well as general health parameters, were recorded. Helicobacter pylori was found in the stomach of 29 patients and in the oral cavity of 16 patients. In only six patients was the bacterium detected simultaneously in the stomach and mouth. Notably, the 10 patients in whom the bacterium was found solely in the mouth did not have serum antibodies to H. pylori. The occurrence of H. pylori in the mouth was found to be correlated neither to any general or oral health parameters, nor to any particular site of collection. This study shows that H. pylori can occur in the oral cavity independently of stomach colonization.
    No preview · Article · Aug 2008 · European Journal Of Oral Sciences
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    Hans-Jörg Linde · Norbert Lehn

    Preview · Article · Mar 2008 · Krankenhaushygiene up2date
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    ABSTRACT: To investigate a 1-week once-daily triple therapy with esomeprazole, moxifloxacin, and rifabutin for rescue therapy of Helicobacter pylori infection. Consecutive patients (n = 103) with at least one previous treatment failure and H. pylori infection resistant to both metronidazole and clarithromycin were treated with esomeprazole 40 mg, moxifloxacin 400 mg, and rifabutin 300 mg, given once daily for 7 days. Eradication was confirmed by histology and culture. CYP2C19 status was determined by polymerase chain reaction-restriction fragment length polymorphism. Intention-to-treat and per-protocol eradication rates were 77.7% (68.4-85.3) and 83.3% (74.4-90.2). Five patients discontinued prematurely (4.8%). Eradication was achieved in 93.1% of poor/intermediate metabolizers and in 78.8% of homozygous extensive metabolizers (p = .14). Eradication rates in patients with one, two, three, and four or more previous failures were 78.3%, 89.6%, 68.6%, and 88.9%, respectively (p = .21). The regimen was effective in seven of nine patients who previously failed quadruple therapy. Post-treatment resistance to moxifloxacin and rifabutin was detected in two (12.5%) and five (31%) patients after treatment failure. Once-daily triple therapy with esomeprazole, moxifloxacin, and rifabutin is a promising, safe, and convenient regimen for rescue therapy of H. pylori infection that may serve as a valuable alternative to quadruple therapy, particularly for patients with intolerance to amoxicillin.
    Full-text · Article · Mar 2008 · Helicobacter
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    ABSTRACT: Multi drug resistance of Mycobacterium tuberculosis (M. tuberculosis) remains a major threat to public health, reinforced by recent reports about the clinical course of patients infected with extensively drug resistant (XDR) strains in South Africa. There is little information about the clinical course of XDR tuberculosis patients in industrialised countries. We evaluated all isolates of M. tuberculosis, in which drug susceptibility testing was performed at our institution since 1997, for multi and extensive drug resistance. Clinical courses of patients infected by strains fulfilling the recently revised criteria for XDR tuberculosis were analysed. Four XDR M. tuberculosis isolates were identified. All patients had immigrated to Germany from Russia, Georgia, and former Yugoslavia and none were infected by the human immunodeficiency virus. All patients where treated for tuberculosis for 5.5 to 15 years and for XDR tuberculosis for 1.9 to 2.5 years. They received inhospital treatment in Germany for 11 months, 4.5 years and twice for 6 years. Non-compliance was an important factor in all four patients, three patients had to be treated in Germanys only locked facility for tuberculosis treatment. One patient with XDR tuberculosis died, one patient had still open pulmonary tuberculosis at last contact and 2 patients were cured. Cases of XDR tuberculosis have been treated in our region for several years. Even in a high income setting, XDR tuberculosis has a tremendous impact on quality of live, outcome and the total cost. All reasonable efforts to prevent the spread of XDR tuberculosis must be made and maintained.
    Full-text · Article · Feb 2008 · BMC Infectious Diseases
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    ABSTRACT: A one-step exchange of an endoprosthesis with periprosthetic infection requires effective antibiotics at high concentrations around the endoprosthesis. We evaluated the tissue distribution of vancomycin and Moxifloxacin in a standardized in vivo model of periprosthetic infection. 36 male rats with periprosthetic infection of the left hind leg, induced by a standardized procedure, received either antibiotic treatment with vancomycin or Moxifloxacin twice daily for 2 weeks, or a sham treatment. After the last administration, different tissues from each animal were evaluated for concentrations of antibiotic. Compared to plasma, the tissue concentrations of Moxifloxacin were higher in all tissues investigated (lung, muscle, fat, bone) and the tissue-plasma ratio of Moxifloxacin was considerably higher than that of vancomycin. The concentrations of Moxifloxacin were equally high in the infected and the uninfected hind leg, whereas the vancomycin concentrations were significantly higher in the infected leg. The standardized model of periprosthetic infection described here can be extrapolated to different bacterial and mycotic pathogens, and also to different antibiotics or therapeutic regimes. It provides a way of correlating tissue concentrations with clinical outcome in future studies.
    Full-text · Article · Jan 2008 · Acta Orthopaedica
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    ABSTRACT: We report the largest documented healthcare-associated outbreak of Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus (PVL(+) MRSA) in Europe. Six index patients from three long-term care facilities (LTCFs) were screened positive for PVL(+) MRSA in 2004 on admission to a community hospital in Germany. The purpose of this prospective study was to describe the prevalence of PVL(+) MRSA in the LTCFs before and after infection control interventions. Screening for MRSA with or without PVL was performed in all three LTCFs in 2004 [453 residents, 240 healthcare workers (HCWs)] and 2005 (440 residents, 192 HCWs). Swabs from anterior nares and wounds, if applicable, were collected. Colonised residents and staff were treated with mupirocin nasal ointment and topical antiseptics, and staff were provided with hygiene education. Total MRSA carrier rate of residents and HCWs in 2004 was 11.3% (PVL(+) MRSA 9.1%, PVL(-) MRSA 2.2%). There were comparable carrier rates between residents and HCWs in each LTCF. All PVL(+) MRSA isolates were of clonal origin (MLST 22) representing a novel spa sequence type t310. A decrease in total MRSA prevalence (from 11.3 to 5.5%) and PVL(+) MRSA (from 9.1 to 3.3%) was observed in 2005. The rate of PVL(-) MRSA remained unaffected. No symptomatic skin infections were noted among residents or HCWs. In this outbreak incomplete control of PVL(+) MRSA presumably resulted from difficult and delayed detection and decolonisation of carriers, incomplete compliance with control measures and lack of enforcement by public health authorities.
    Full-text · Article · Nov 2007 · Journal of Hospital Infection
  • J Langgartner · N Lehn · T Glück · H Herzig · F Kees
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    ABSTRACT: The antibacterial effect of piperacillin/sulbactam depends on the time of drug concentration above the minimal inhibitory concentration (MIC). Therefore, continuous infusion (CI) may be a more rational approach than standard intermittent short-term infusion (SI). The study investigated whether CI achieves effective drug concentrations comparable with SI. Seven intensive care unit patients received either piperacillin/sulbactam as 4/1 g intravenous infusion over 15-20 min every 8 h or as 4/1 g intravenous loading dose (15-20 min) followed by 8/2 g intravenous CI per 24 h. After 2 days, regimes were crossed over. Pharmacokinetic parameters (mean +/- SD) for SI piperacillin/sulbactam were: (1) peak serum concentration: piperacillin 231 +/- 66 mg/l, sulbactam 53.1 +/- 15.0 mg/l; (2) minimum serum concentration: piperacillin 11.5 +/- 14.8 mg/l, sulbactam 4.2 +/- 3.5 mg/l; (3) clearance: piperacillin 197 +/- 72 ml/min (CI 269 +/- 123 ml/min), sulbactam 167 +/- 61 ml/min (CI 212 +/- 109 ml/min); (4) half-life: piperacillin 2.4 +/- 1.2 h, sulbactam 3.1 +/- 1.6 h. Steady-state concentrations during CI were 25.5 +/- 14.5 mg/l for piperacillin and 8.0 +/- 3.7 mg/l for sulbactam. Average serum concentrations were comparable in both regimens. A large German survey demonstrated that approximately 89% of Pseudomonas aerugionsa have an MIC < or =16 mg/l and approximately 82% have an MIC < or =8 mg/l. According to this threshold, appropriate anti-bacterial concentrations of piperacillin/sulbactam were achievable with CI. CI dosing has the additional advantage that less drug is necessary. Further prospective studies are warranted to compare the clinical efficacy of CI and SI regimens in bacterial infections.
    No preview · Article · Sep 2007 · Chemotherapy

  • No preview · Article · Aug 2007 · Zeitschrift für Gastroenterologie
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    ABSTRACT: In order to assess the speed and accuracy of a real-time PCR assay targeting the lukS-PV gene of Panton-Valentine leukocidin (PVL)-positive Staphylococcus aureus, 700 S. aureus strains were tested and the results were compared to those achieved with block cycler PCR. Cross-reactivity was tested with 166 other bacterial species. Using this homogeneous real-time PCR assay format, the presence or absence of genetic information for PVL, which is also found in community-associated methicillin-resistant S. aureus, was correctly identified from pure culture and directly in various types of clinical specimens.
    No preview · Article · Mar 2007 · European Journal of Clinical Microbiology

Publication Stats

6k Citations
884.47 Total Impact Points

Institutions

  • 1995-2013
    • Universität Regensburg
      • • Department of Medical Microbiology and Hygiene
      • • Department of Pathology
      Ratisbon, Bavaria, Germany
    • Klinikum Bayreuth GmbH
      Bayreuth, Bavaria, Germany
    • Ludwig-Maximilians-University of Munich
      München, Bavaria, Germany
    • Freie Universität Berlin
      Berlín, Berlin, Germany
  • 2011
    • Institute of Biochemistry and Biophysics
      Teheran, Tehrān, Iran
  • 2002-2011
    • University Hospital Regensburg
      • Institut für Medizinische Mikrobiologie und Hygiene
      Ratisbon, Bavaria, Germany
  • 2000
    • Max von Pettenkofer-Institut
      München, Bavaria, Germany
  • 1998-2000
    • Technische Universität Dresden
      • Medizinische Klinik und Poliklinik I
      Dresden, Saxony, Germany
  • 1999
    • Friedrich-Alexander-University of Erlangen-Nürnberg
      Erlangen, Bavaria, Germany
    • Bundeswehrzentralkrankenhaus Koblenz
      Coblenz, Rheinland-Pfalz, Germany
    • Carl Gustav Carus-Institut
      Pforzheim, Baden-Württemberg, Germany
  • 1994-1999
    • Technische Universität München
      • • Klinik und Poliklinik für Mund- Kiefer- und Gesichtschirurgie
      • • Department of Microbiology (Z I E L)
      • • Department of Microbiology
      • • Institut für Medizinische Mikrobiologie, Immunologie und Hygiene
      München, Bavaria, Germany
  • 1997-1998
    • Otto-von-Guericke-Universität Magdeburg
      Magdeburg, Saxony-Anhalt, Germany
  • 1996
    • University Hospital Magdeburg
      Magdeburg, Saxony-Anhalt, Germany