18 results on '"Lorenz Leitritz"'
Search Results
2. Kontakt zu landwirtschaftlichen Betrieben und Toxoplasma-gondii-Infektionen
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Holger Dressel, Dennis Nowak, Erika von Mutius, Georg Praml, Katja Radon, Julia Eckart, Martina Schmid, Lorenz Leitritz, Doris Windstetter, and Joerg Reichert
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Hygiene hypothesis ,biology ,business.industry ,parasitic diseases ,Immunology ,Immunology and Allergy ,Medicine ,Toxoplasma gondii ,Context (language use) ,business ,biology.organism_classification ,Virology - Abstract
Background Within the context of the hygiene hypothesis the authors aimed to study the potential association between farming-related risk factors and Toxoplasma gondii (T. gondii) seropositivity.
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- 2004
3. Culture independent and rapid identification of bacterial pathogens in necrotising fasciitis and streptococcal toxic shock syndrome by fluorescence in situ hybridisation
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Kristin Adler, Lorenz Leitritz, Ingo B. Autenrieth, Karlheinz Trebesius, Jürgen Heesemann, and Sören Schubert
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Adult ,Male ,Microbiology (medical) ,medicine.medical_specialty ,Time Factors ,Streptococcus pyogenes ,medicine.drug_class ,Immunology ,Antibiotics ,Necrotising fasciitis ,Penicillins ,medicine.disease_cause ,Sensitivity and Specificity ,Microbiology ,Medical microbiology ,Pregnancy ,Streptococcal Infections ,medicine ,Humans ,Immunology and Allergy ,Fasciitis, Necrotizing ,Pregnancy Complications, Infectious ,In Situ Hybridization, Fluorescence ,biology ,Toxic shock syndrome ,Penicillin G ,General Medicine ,Middle Aged ,biology.organism_classification ,medicine.disease ,Antimicrobial ,Shock, Septic ,Proteus mirabilis ,Female ,Bacteria - Abstract
Fluorescence in situ hybridisation (FISH) targeted to ribosomal RNA is well established for studies in environmental microbiology. Initial applications of this technique in the field of medical microbiology showed that FISH is also a suitable means for the rapid, reliable and cultivation-independent identification of bacterial pathogens. In particular, for infectious diseases that follow a fulminant live-threatening course, such as sepsis or necrotising fasciitis (NF), a fast and reliable detection technique is of great importance. This study describes the development of an rRNA-targeted oligonucleotide set covering more than 95% of the pathogens associated with NF. These probes were tested with a broad collection of target and non-target organisms and found to be highly specific. Subsequently, the FISH approach was applied for the direct detection of bacterial pathogens in clinical samples. Two cases of NF and one case of streptococcal toxic shock syndrome (STSS) were analysed. FISH correctly identified almost all pathogens present in the samples examined within 2–3 h. However, Proteus mirabilis, which was identified in one sample by conventional methods was detected as a rod-shaped bacteria but could not be identified by FISH, since no specific probe was available for this particular organism. In contrast, identification of pathogens in these samples by conventional laboratory methods took 48–72 h. Furthermore, in one patient with pre-sampling antimicrobial therapy bacteria could not be grown from any of the samples. FISH unequivocally revealed the presence of Streptococcus pyogenes in affected tissue samples from this patient. In an experimental setting we demonstrated that FISH readily identifies S. pyogenes cells rendered non-cultivable by antibiotic treatment. Thus, FISH holds great promise for rapid identification of pathogens in fulminant infections such as NF, particularly in cases when pre-sampling antimicrobial therapy hampers culture of the causative agent.
- Published
- 2000
4. Pulmonary Toxoplasmosis in Bone Marrow Transplant Recipients: Report of Two Cases and Review
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Andreas Sing, Lorenz Leitritz, Jürgen Heesemann, Ingo B. Autenrieth, Andreas Szabados, Andreas Roggenkamp, Hans-Jochem Kolb, and Volker Fingerle
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Adult ,Microbiology (medical) ,Pathology ,medicine.medical_specialty ,Lung Diseases, Parasitic ,Opportunistic infection ,Autopsy ,Fatal Outcome ,medicine ,Animals ,Humans ,Bone Marrow Transplantation ,Lung ,biology ,medicine.diagnostic_test ,business.industry ,Respiratory disease ,Toxoplasma gondii ,DNA, Protozoan ,Middle Aged ,medicine.disease ,biology.organism_classification ,Toxoplasmosis ,surgical procedures, operative ,Infectious Diseases ,Bronchoalveolar lavage ,medicine.anatomical_structure ,Female ,Bone marrow ,business ,Bronchoalveolar Lavage Fluid ,Toxoplasma - Abstract
Toxoplasma gondii may cause disseminated disease in bone marrow transplant (BMT) recipients. Pulmonary toxoplasmosis in BMT patients is rarely described. Mortality rates of >90% have been previously reported. Since pulmonary toxoplasmosis is extremely difficult to diagnose, it is very often detected only at autopsy. Two cases of pulmonary toxoplasmosis in BMT recipients that were diagnosed by visualization of T. gondii tachyzoites in bronchoalveolar lavage fluid and by a new semi-nested PCR method amplifying 18S rRNA from bronchoalveolar lavage fluid are presented, and the literature on pulmonary toxoplasmosis in BMT patients is reviewed.
- Published
- 1999
5. In vitroandin vivoexpression studies ofyopEfromYersinia enterocoliticausing thegfpreporter gene
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Andreas Roggenkamp, Jürgen Heesemann, R. Zumbihl, Lorenz Leitritz, Christoph A. Jacobi, and Alexander Rakin
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Neutrophils ,Immunoprecipitation ,Recombinant Fusion Proteins ,Green Fluorescent Proteins ,Gene Expression ,Microbiology ,Green fluorescent protein ,Mice ,Plasmid ,Genes, Reporter ,Gene expression ,Tumor Cells, Cultured ,Animals ,Secretion ,Luciferase ,Luciferases ,Yersinia enterocolitica ,Molecular Biology ,Reporter gene ,biology ,Biological Transport ,biology.organism_classification ,Precipitin Tests ,Molecular biology ,Luminescent Proteins ,Luminescent Measurements ,Bacterial Outer Membrane Proteins - Abstract
The Yersinia outer protein YopE belongs to the translocated effector proteins of pathogenic yersiniae. We constructed various truncated yopE genes fused to gfp (encoding the green fluorescent protein) to study yopE gene expression and YopE–GFP translocation of Y. enterocolitica in cell culture and mouse infection models. The hybrid gene fusions were co-expressed in Y. enterocolitica (i) on a low-copy plasmid in the presence of the virulence plasmid pYV08 (in trans configuration) and (ii) after co-integration by homologous recombination of a yopE–gfp-carrying suicide plasmid into pYV08 (co-integrate configuration). After 30 min of infection of HEp-2 cell monolayers, extracellularly located yersiniae began to emit green fluorescence after excitation. In contrast, internalized bacteria were weakly fluorescent. Translocation of YopE–GFP into HEp-2 cells by attached yersiniae was visualized by optical sectioning of fluorescent HEp-2 cells using confocal laser scanning microscopy and was confirmed by immunoprecipitation of cytosolic YopE–GFP from selectively solubilized HEp-2 cells. The co-translocation of other Yops was not significantly impaired by YopE–GFP as shown by YopH/YopE-mediated suppression of the oxidative burst of infected neutrophils. The time course of yopE–gfp expression (in trans as well as in the co-integrate configuration) in the HEp-2 cell infection model as well as after in vitro induction was studied using a highly sensitive CCD camera and a flow cytometer. Similar results were obtained with a YopE–LUC (firefly luciferase) protein fusion as reporter. After intraperitoneal, intravenous and orogastrical infection of Balb/c mice with the recombinant yersiniae strains, green fluorescing bacteria could be visualized microscopically in the peritoneum, the spleen, the liver and in the Peyer's patches. However, only weakly fluorescent yersiniae were observed in the intestinal lumen. These results were quantified by flow cytometric measurements. The application of gfp as a reporter gene turned out to be promising for the study of protein translocation by protein type III secretion systems and differential virulence gene expression in vivo.
- Published
- 1998
6. Passive immunity to infection with Yersinia spp. mediated by anti-recombinant V antigen is dependent on polymorphism of V antigen
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Andreas Roggenkamp, Lorenz Leitritz, J Heesemann, A Kessler, and Anna M. Geiger
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Pore Forming Cytotoxic Proteins ,Yersinia Infections ,Molecular Sequence Data ,Immunology ,Yersinia pseudotuberculosis Infections ,Cross immunity ,Microbiology ,Mice ,Antigen ,Antibody Specificity ,medicine ,Animals ,Yersinia pseudotuberculosis ,LcrV ,Amino Acid Sequence ,Serotyping ,Yersinia enterocolitica ,Antiserum ,Antigens, Bacterial ,Mice, Inbred BALB C ,Polymorphism, Genetic ,Base Sequence ,biology ,Immune Sera ,Immunization, Passive ,Yersiniosis ,medicine.disease ,biology.organism_classification ,Virology ,Recombinant Proteins ,Infectious Diseases ,bacteria ,Female ,Parasitology ,Research Article - Abstract
The V antigen is a 37-kDa secreted polypeptide encoded on the 70-kb virulence plasmid of pathogenic Yersinia spp. Besides having regulatory functions, it is known to be a virulence factor and a protective antigen. DNA sequencing of the most common serotypes of human pathogenic Yersinia enterocolitica and Y. pseudotuberculosis revealed that two evolutionary distinct types of V antigen exist in Yersinia spp. One type is represented by Y. enterocolitica serotype 08 strains WA, WA-314, and NCTC 10938 (designated LcrV-YenO8); the other type comprises Y. pestis, Y. pseudotuberculosis, and Y. enterocolitica serotypes O3, O9, and O5,27 (LcrV-Yps). A hypervariable region between amino acids 225 and 232 represents the main difference between the two types. By raising monospecific antisera against both types of V antigen (anti-rVO8 and anti-rVO3), we were able to demonstrate that, in general, passive immunization of mice against a challenge with yersiniae was possible with both anti-Y. enterocolitica V antigen sera. However, anti-V antigen serum was protective only if the immunizing V antigen was the same type as the V antigen produced by the infective strain. The failure of the American V antigen type represented by Y. enterocolitica serotype O8 to protect against Yersinia spp. carrying the other V antigen type (LcrV-Yps) could be an explanation for the presence of plague foci in American countries.
- Published
- 1997
7. Deletion of amino acids 29 to 81 in adhesion protein YadA of Yersinia enterocolitica serotype O:8 results in selective abrogation of adherence to neutrophils
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Lorenz Leitritz, R Schmitt, J Heesemann, Klaus Ruckdeschel, and Andreas Roggenkamp
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DNA, Bacterial ,Signal peptide ,Blood Bactericidal Activity ,Yersinia Infections ,Neutrophils ,Molecular Sequence Data ,Immunology ,Mutant ,Virulence ,Biology ,Yersinia ,Microbiology ,Bacterial Adhesion ,Cell Line ,Mice ,Phagocytosis ,Animals ,Humans ,Serotyping ,Adhesins, Bacterial ,Yersinia enterocolitica ,DNA Primers ,Sequence Deletion ,Autoagglutination ,Base Sequence ,biology.organism_classification ,Enterobacteriaceae ,Bacterial adhesin ,Infectious Diseases ,Female ,Parasitology ,Research Article - Abstract
In order to analyze the multiple functions of the yersinia adhesin YadA in more detail, we constructed an N-terminally truncated YadA protein (deletion of amino acids [aa] 29 to 81) of Yersinia enterocolitica serotype 0:8. The region aa 29 to 81 of YadA is located between the signal sequence and the amino-terminal hydrophobic domain (aa 80 to 101), which is involved in surface polymerization and collagen binding. The deletion of aa 29 to 81 (resulting in YadADelta29-81) had no effect on the well-known features of YadA such as autoagglutination, serum resistance, HEp-2 cell adherence, binding of collagen, and binding of the complement-inhibiting factor H. In contrast to this, mutant WA(pYVO8-A-Delta29-81), producing the truncated YadADelta29-81 had lost the ability to adhere to polymorphonuclear leukocytes and to induce an oxidative burst. This functional deficiency was comparable to that of a yadA-null mutant (K. Ruckdeschel, A. Roggenkamp, S. Schubert, and J. Heesemann, Infect. Immun. 64:724-733, 1996). Moreover, mutant WA(pYVO8-ADelta29-81) turned out to be attenuated in virulence comparably to the yadA-null mutant, as demonstrated with orogastrically and intravenously infected mice. In summary, this study shows that specific functions of YadA (i) can be impaired by designed mutations and (ii) are important in distinct stages of the infection process.
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- 1996
8. Conservative Management of Biliary Obstruction Due to Fasciola hepatica
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Michael Mannstadt, Johannes R. Bogner, Andreas Sing, Lorenz Leitritz, and Karine Brenner-Maucher
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Adult ,Microbiology (medical) ,Fascioliasis ,medicine.medical_specialty ,Abdominal pain ,Conservative management ,Helminthiasis ,Gastroenterology ,Diagnosis, Differential ,Internal medicine ,medicine ,Animals ,Humans ,Fasciola hepatica ,Eosinophilia ,Triclabendazole ,Anthelmintics ,Cholestasis ,biology ,Bile duct ,business.industry ,medicine.disease ,biology.organism_classification ,Surgery ,Infectious Diseases ,medicine.anatomical_structure ,Biliary tract ,Benzimidazoles ,Female ,medicine.symptom ,Complication ,business - Abstract
We report a case of temporary biliary obstruction due to fascioliasis. This case report shows that in Central Europe, fascioliasis is one of the differential diagnoses of abdominal pain, especially if it is associated with eosinophilia. Successful medical treatment is possible even with obstruction of the bile duct.
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- 2000
9. PCR for Detection and Identification of Abiotrophia spp
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Andreas Roggenkamp, Kerstin Baus, Lorenz Leitritz, Jürgen Heesemann, and Enevold Falsen
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Microbiology (medical) ,Fastidious organism ,Molecular Sequence Data ,Bacteremia ,Biology ,medicine.disease_cause ,Polymerase Chain Reaction ,Sensitivity and Specificity ,law.invention ,law ,RNA, Ribosomal, 16S ,medicine ,Humans ,Ribosomal DNA ,Polymerase chain reaction ,DNA Primers ,Genetics ,Base Sequence ,Streptococcus ,Bacteriology ,Endocarditis, Bacterial ,Abiotrophia ,Amplicon ,16S ribosomal RNA ,biology.organism_classification ,Restriction fragment length polymorphism ,Polymorphism, Restriction Fragment Length - Abstract
Members of the genus Abiotrophia , formerly known as nutritionally variant streptococci, are important pathogens causing septicemia and endocarditis. Cultivation and biochemical differentiation of Abiotrophia spp. are often difficult. Based on 16S rRNA sequences, two PCR assays for detection and identification of Abiotrophia spp. were developed. The first PCR assay was positive for all Abiotrophia spp. Subsequently performed restriction fragment length polymorphism analysis allowed the verification of the PCR amplicons and the differentiation of the three species. The second PCR assay was positive only for A. elegans , the most fastidious species of Abiotrophia . Both PCR assays were shown to be specific and sensitive and should facilitate the identification of Abiotrophia spp.
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- 1998
10. Prospective study on nontuberculous mycobacteria in patients with and without cystic fibrosis
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Matthias Griese, J Heesemann, Volker Fingerle, Andreas Roggenkamp, Lorenz Leitritz, and Anna M. Geiger
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Microbiology (medical) ,Adult ,Male ,medicine.medical_specialty ,Pancreatic disease ,Adolescent ,Cystic Fibrosis ,Immunology ,HIV Infections ,Cystic fibrosis ,Mycobacterium ,Cohort Studies ,Medical microbiology ,Internal medicine ,Immunology and Allergy ,Medicine ,Humans ,Prospective Studies ,Prospective cohort study ,Child ,Mycobacterium Infections ,biology ,Respiratory tract infections ,business.industry ,Incidence (epidemiology) ,Respiratory disease ,Sputum ,Infant ,General Medicine ,Middle Aged ,bacterial infections and mycoses ,medicine.disease ,biology.organism_classification ,Surgery ,Cross-Sectional Studies ,Child, Preschool ,Nontuberculous mycobacteria ,Female ,business - Abstract
Recent reports indicated an increase of nontuberculous mycobacteria (NTM) in cystic fibrosis (CF) patients. However, it is still a matter of discussion whether criteria for diagnosis of NTM pulmonary infection established by the American Thoracic Society (ATS) are applicable for CF patients. We determined incidence and prevalence of NTM in CF patients and non-CF patients without HIV infection, and validity of ATS criteria for CF patients. Over a period of 2 years, 1,251 respiratory samples were investigated for mycobacteria from 91 CF and 162 non-CF patients. For all patients with NTM recovery, we reviewed clinical charts and determined outcome for up to 2 years. Incidence and prevalence for repeated recovery of NTM were higher in CF patients, but not significantly. CF patients with repeated recovery of NTM met clinical and bacteriological ATS criteria, but radiographic criteria were not met. Treated CF patients showed favorable clinical outcomes, as opposed to untreated patients. We propose a modified definition for diagnosis and hence treatment of NTM pulmonary infection in CF patients.
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- 2003
11. Evaluation of BACTEC MGIT 960 and BACTEC 460TB systems for recovery of mycobacteria from clinical specimens of a university hospital with low incidence of tuberculosis
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Jürgen Heesemann, Bettina Bücherl, Sören Schubert, Lorenz Leitritz, Andreas Roggenkamp, and Adelheid Masch
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Microbiology (medical) ,Tuberculosis ,Transport time ,Microbiology ,Mycobacterium ,Hospitals, University ,Medicine ,Humans ,Bacteriological Techniques ,Mycobacterium Infections ,biology ,business.industry ,Incidence (epidemiology) ,Incidence ,Mycobacteriology and Aerobic Actinomycetes ,University hospital ,biology.organism_classification ,medicine.disease ,equipment and supplies ,bacterial infections and mycoses ,Culture Media ,Mycobacterium tuberculosis complex ,Nontuberculous mycobacteria ,business - Abstract
Clinical samples obtained over a period of 8 months ( n = 2,624) were processed in parallel with the BACTEC 460TB system, with the MGIT 960 system, and in Löwenstein-Jensen (LJ) medium, resulting in the recovery of 127 mycobacteria. Recovery rates in combinations of the BACTEC 460TB or MGIT 960 system with LJ were, respectively, 94.7 and 94.7% for Mycobacterium tuberculosis complex ( n = 57) and 91.4 and 70.0% for nontuberculous mycobacteria ( n = 70). Contamination rates, elevated in the MGIT 960 system, were associated with patients (cystic fibrosis) and type of material but not with transport time. Detection time was reduced in the MGIT 960 system.
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- 2001
12. Cost reduction after introduction of a multidisciplinary infectious disease service at a German university hospital
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Johannes R. Bogner, C. Rupp, Lorenz Leitritz, S. Wolf, and D. Schlöndorff
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Microbiology (medical) ,Male ,Pediatrics ,medicine.medical_specialty ,Cost Control ,medicine.drug_class ,Urinary system ,Antibiotics ,Bacteremia ,Skin infection ,Drug Costs ,Sepsis ,Hospitals, University ,Pharmacotherapy ,Germany ,medicine ,Humans ,Hospital Costs ,Skin Diseases, Infectious ,Referral and Consultation ,Aged ,business.industry ,General Medicine ,Pneumonia ,Middle Aged ,medicine.disease ,Anti-Bacterial Agents ,Infectious Diseases ,Infectious disease (medical specialty) ,Cellulitis ,Urinary Tract Infections ,Female ,business - Abstract
Background: In 1997 an infectious disease service (IDS) similar to those in the US was established at a university hospital in Munich, Germany. Patients and Methods: We assessed the economic impact of the new policy by performing a cost comparison analysis. Inpatients with pneumonia, skin infections/cellulitis, urinary tract infections (UTI) and bacteremia/sepsis were assigned to two groups: patients from a 6-month period after the establishment of the IDS (post-IDS group) were compared with similar patients before the implementation of the ID-servide (pre-IDS group). Costs of microbiological investigation (MB), antibiotic treatment (AB), clinical imaging (CI), total costs and length of antibiotic therapy were analyzed. Results: Patients with UTIs in the post IDS-group had 39% fewer MBs (p < 0.05) than patients in the pre-IDS group, resulting in a 33% decrease in average MB costs (p < 0.05). In the total group, in which subgroups with pneumonia, skin infection and UTI were summarized, the post-IDS group had 37% fewer MBs (p < 0.05) resulting in MB cost reductions of 34% (p < 0.05). There were no significant differences in expenditures for AB and CI and in the average length of antibiotic therapy. Conclusion: This study shows that continuous consultation by an IDS does not increase diagnostic and treatment costs, but results in significant cost reductions.
- Published
- 2001
13. Bakteriologie, Mykologie, Parasitologie und Virologie
- Author
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A. Sing, Lorenz Leitritz, S. Schubert, U. Koszinowski, H. Hengel, J. Haas, J. Eberle, I. B. Autenrieth, U. Hauser, A. Roggenkamp, J. Heesemann, and B. Wilske
- Abstract
Infektionskrankheiten gehoren weltweit zu den haufigsten Todesursachen. Zu den Voraussetzungen fur eine effektive Therapie und Prophylaxe von Infektionen gehoren die zuverlassige klinische Verdachtsdiagnose und die nachfolgende mikrobiologische Diagnostik.
- Published
- 2000
14. Invasion and Intracellular Development of the Human Granulocytic Ehrlichiosis Agent in Tick Cell Culture
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Ulrike G. Munderloh, Timothy J. Kurtti, Martha A. Mellencamp, Joan M. Hautman, Lorenz Leitritz, Volker Fingerle, Brent W. Huberty, Curtis M. Nelson, Steven D. Jauron, Gilbert G. Ahlstrand, Barbara Greig, S. Fred Hayes, and Jesse L. Goodman
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Microbiology (medical) ,Cell division ,Chlamydiology and Rickettsiology ,Cell ,Cell Culture Techniques ,Ehrlichia ,HL-60 Cells ,Tick ,Cell Line ,Dogs ,Ticks ,parasitic diseases ,medicine ,Animals ,Humans ,Bacteriological Techniques ,biology ,Ehrlichiosis ,biology.organism_classification ,bacterial infections and mycoses ,Virology ,Microscopy, Electron ,medicine.anatomical_structure ,Cell culture ,Ixodes scapularis ,Ehrlichiosis (canine) ,Rickettsiales - Abstract
Human granulocytotropic ehrlichias are tick-borne bacterial pathogens that cause an acute, life-threatening illness, human granulocytic ehrlichiosis (HGE). Ehrlichias within neutrophil granulocytes that invade tick bite sites are likely ingested by the vector, to be transmitted to another mammalian host during the tick’s next blood meal. Thus, the cycle of replication and development in the vector is prerequisite to mammalian infection, and yet these events have not been described. We report tick cell culture isolation of two strains of the HGE agent directly from an infected horse and a dog and have also established a human isolate from HL60 culture in tick cells, proving that the blood stages of the HGE agent are infectious for tick cells, as are those replicating in the human cell line HL60. This required changes to the culture system, including a new tick cell line. In tick cell layers, the HGE agent induced foci of infection that caused necrotic plaques and eventual destruction of the culture. Using the human isolate and electron microscopy, we monitored adhesion, internalization, and replication in vector tick cells. Both electron-lucent and -dense forms adhered to and entered cells by a mechanism reminiscent of phagocytosis. Ehrlichial cell division was initiated soon after, resulting in endosomes filled with numerous ehrlichias. During early development, pale ehrlichias with a tight cell wall dominated, but by day 2, individual bacteria condensed into dark forms with a rippled membrane. These may become compacted into clumps where individual organisms are barely discernible. Whether these are part of an ehrlichia life cycle or are degenerating is unknown.
- Published
- 1999
15. Contribution of the Mn-cofactored superoxide dismutase (SodA) to the virulence of Yersinia enterocolitica serotype O8
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J Heesemann, T Bittner, Andreas Roggenkamp, Andreas Sing, and Lorenz Leitritz
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Neutrophils ,Immunology ,Mutant ,Molecular Sequence Data ,Virulence ,medicine.disease_cause ,Microbiology ,Superoxide dismutase ,Mice ,medicine ,Animals ,Humans ,Cloning, Molecular ,Yersinia enterocolitica ,Escherichia coli ,chemistry.chemical_classification ,Reactive oxygen species ,Mice, Inbred BALB C ,biology ,Base Sequence ,Superoxide Dismutase ,Yersiniosis ,food and beverages ,medicine.disease ,biology.organism_classification ,Enterobacteriaceae ,Mice, Inbred C57BL ,Infectious Diseases ,chemistry ,Luminescent Measurements ,Mutation ,biology.protein ,bacteria ,Parasitology ,Female ,Research Article - Abstract
Enteric pathogens harbor a set of enzymes (e.g., superoxide dismutases [SOD]) for detoxification of endogenous and exogenous reactive oxygen species which are encountered during infection. To analyze the role of the Mn-cofactored SOD (SodA) in the pathogenicity of yersiniae, we cloned the sodA gene of Yersinia enterocolitica serotype O8 by complementation of an Escherichia coli sodA sodB mutant and subsequently constructed an isogenic mutant by allelic exchange. Sequence analysis revealed an open reading frame that enabled the deduction of a sequence of 207 amino acids with 85% identity to SodA of E. coli. In a mouse infection model, the sodA null mutant was strongly attenuated in comparison to its parental strain. After intravenous infection, the survival and multiplication of the mutant in the spleen and liver were markedly reduced. In contrast, inactivation of sodA had only minor effects on survival and multiplication in the gut and Peyer's patches, as could be demonstrated in the orogastric infection model. The reduction in virulence was accompanied by a low but significant increase of susceptibility of the soda mutant to bacterial killing by polymorphonuclear leukocytes (PMN) and an alteration of the intracellular chemiluminescence response of PMN. These results suggest that the resistance of Y. enterocolitica to exogenous oxygen radicals produced by phagocytes involves the Mn-cofactored SOD. The important role of sodA for the pathogenicity of Y. enterocolitica could also be due to detoxification of endogenous, metabolically produced oxygen radicals which are encountered by extracellular enteric pathogens during the invasion of the host.
- Published
- 1997
16. First-Glance Diagnosis of Strongyloides stercoralis Autoinfection by Stool Microscopy
- Author
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Andreas Sing, Lorenz Leitritz, Johannes R. Bogner, and Jürgen Heesemann
- Subjects
Adult ,Microbiology (medical) ,Microscopy ,Pathology ,medicine.medical_specialty ,Helminthiasis ,Biology ,Stool specimen ,medicine.disease ,biology.organism_classification ,Strongyloides stercoralis ,Feces ,Stool microscopy ,Strongyloidiasis ,medicine ,Animals ,Humans ,Female ,Parasitology - Abstract
We report a case of autoinfection due to Strongyloides stercoralis in a 27-year-old Ethiopian AIDS patient living in Germany for nearly 3 years. This case was diagnosed on the basis of a single-view field in microscopy of a freshly obtained formalin-fixed stool specimen showing both rhabditiform and filariform larvae. The diagnosis of autoinfection by microscopy is discussed in detail.
- Published
- 1999
17. FARMING EXPOSURE IN CHILDHOOD AND MARKERS OF INFECTION – TWO DISTINCT FACTORS IN THE DEVELOPMENT OF ATOPY?
- Author
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Lorenz Leitritz, Doris Windstetter, Erika von Mutius, Julia Eckart, Joerg Reichert, Katja Radon, Holger Dressel, Dennis Nowak, and Georg Praml
- Subjects
Atopy ,Epidemiology ,Agriculture ,business.industry ,Immunology ,medicine ,Biology ,medicine.disease ,business - Published
- 2004
18. Farming exposure in childhood, exposure to markers of infections and the development of atopy in rural subjects
- Author
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J. Reichert, Holger Dressel, Dennis Nowak, Martina Schmid, Lorenz Leitritz, Georg Praml, Julia Eckart, E. von Mutius, M. Schosser, Katja Radon, and D Windstetter
- Subjects
Adult ,Rural Population ,medicine.medical_specialty ,Cross-sectional study ,Immunology ,Context (language use) ,Helicobacter Infections ,Atopy ,Hygiene hypothesis ,Risk Factors ,Epidemiology ,Hypersensitivity ,Odds Ratio ,Animals ,Humans ,Immunology and Allergy ,Medicine ,Animal Husbandry ,Child ,Helicobacter pylori ,business.industry ,Infant ,Agriculture ,Hygiene ,Environmental Exposure ,Environmental exposure ,Odds ratio ,Allergens ,medicine.disease ,Toxoplasmosis ,Cross-Sectional Studies ,Milk ,Animals, Domestic ,Child, Preschool ,Immunoglobulin G ,Cattle ,business ,Toxoplasma - Abstract
Background Within the context of the hygiene hypothesis, we aimed to study the potential association between farming-related risk factors and Toxoplasma gondii (T. gondii) as well as Helicobacter pylori (H. pylori) seropositivity. Methods The study included questionnaire data and serum samples of 321 young adults living in a rural environment. Serum samples were analysed for specific IgE to a common panel of aeroallergens (SX1) as well as IgG against T. gondii and H. pylori. Results Regular contact with animal stables before the age of 3 years (odds ratio (OR) (95% confidence interval): 2.0 [1.0; 4.0]) and unpasteurized milk consumption at age 6 years (1.8 [1.0; 3.3]) were the strongest risk factors for T. gondii infection. None of the farming-related factors were significantly associated with H. pylori infection. Current consumption of raw farm milk was not significantly associated with H. pylori infection (2.1 [0.8; 5.3]). Regular contact with animal houses before the age of 7 years was the strongest predictor for atopy (0.49 [0.26–0.96]). The reduction in risk could not be further decreased by any other factor under consideration. After adjustment for animal house contact, the OR for atopy was decreased by raw milk consumption and H. pylori infection in an additive manner. Conclusion Exposure to farming environments in childhood might predict T. gondii seropositivity in rural subjects. Nevertheless, the strongest predictor for atopy in rural subjects seems to be regular contact with farm animals. Whether T. gondii infection is an intermediate factor in the association between farm contact and atopy needs to be confirmed in larger studies.
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