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1.
Eur J Microbiol Immunol (Bp) ; 3(1): 36-43, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24265916

RESUMO

Enterocolitis caused by Campylobacter jejuni represents an important socioeconomic burden worldwide. The host-specific intestinal microbiota is essential for maintaining colonization resistance (CR) against C. jejuni in conventional mice. Notably, CR is abrogated by shifts of the intestinal microbiota towards overgrowth with commensal E. coli during acute ileitis. Thus, we investigated whether oral transplantation (TX) of ileal microbiota derived from C. jejuni susceptible mice with acute ileitis overcomes CR of healthy conventional animals. Four days following ileitis microbiota TX or ileitis induction and right before C. jejuni infection, mice displayed comparable loads of main intestinal bacterial groups as shown by culture. Eight days following ileitis induction, but not ileal microbiota TX, however, C. jejuni could readily colonize the gastrointestinal tract of conventional mice and also translocate to extra-intestinal tissue sites such as mesenteric lymph nodes, spleen, liver, and blood within 4 days following oral infection. Of note, C. jejuni did not further deteriorate histopathology following ileitis induction. Lack of C. jejuni colonization in TX mice was accompanied by a decrease of commensal E. coli loads in the feces 4 days following C. jejuni infection. In summary, oral ileal microbiota TX from susceptible donors is not sufficient to abrogate murine CR against C. jejuni.

2.
Eur J Microbiol Immunol (Bp) ; 3(2): 126-34, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24265929

RESUMO

Non-pathogenic Escherichia coli (Ec) strains K12 (EcK12) and Nissle 1917 (EcN) are used for gene technology and probiotic treatment of intestinal inflammation, respectively. We investigated intestinal colonization and potential pro-inflammatory properties of EcK12, EcN, and commensal E. coli (EcCo) strains in Toxoplasma (T.) gondii-induced acute ileitis. Whereas gnotobiotic animals generated by quintuple antibiotic treatment were protected from ileitis, mice replenished with conventional microbiota suffered from small intestinal necrosis 7 days post-T. gondii infection (p.i.). Irrespective of the Ec strain, recolonized mice revealed mild to moderate histopathological changes in their ileal mucosa. Upon stable recolonization with EcK12, EcN, or EcCo, development of inflammation was accompanied by pro-inflammatory responses at day 7 p.i., including increased ileal T lymphocyte and apoptotic cell numbers compared to T. gondii-infected gnotobiotic controls. Strikingly, either Ec strain was capable to translocate to extra-intestinal locations, such as MLN, spleen, and liver. Taken together, Ec strains used in gene technology and probiotic treatment are able to exert inflammatory responses in a murine model of small intestinal inflammation. In conclusion, the therapeutic use of Ec strains in patients with broad-spectrum antibiotic treatment and/or intestinal inflammation should be considered with caution.

3.
Eur J Microbiol Immunol (Bp) ; 2(1): 2-11, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24611115

RESUMO

Campylobacter (C.) jejuni is among the leading bacterial agents causing enterocolitis worldwide. Despite the high prevalence of C. jejuni infections and its significant medical and economical consequences, intestinal pathogenesis is poorly understood. This is mainly due to the lack of appropriate animal models. In the age of 3 months, adult mice display strong colonization resistance (CR) against C. jejuni. Previous studies underlined the substantial role of the murine intestinal microbiota in maintaining CR. Due to the fact that the host-specific gut flora establishes after weaning, we investigated CR against C. jejuni in 3-week-old mice and studied intestinal and extra-intestinal immunopathogenesis as well as age dependent differences of the murine colon microbiota. In infant animals infected orally immediately after weaning C. jejuni strain B2 could stably colonize the gastrointestinal tract for more than 100 days. Within six days following infection, infant mice developed acute enterocolitis as indicated by bloody diarrhea, colonic shortening, and increased apoptotic cell numbers in the colon mucosa. Similar to human campylobacteriosis clinical disease manifestations were self-limited and disappeared within two weeks. Interestingly, long-term C. jejuni infection was accompanied by distinct intestinal immune and inflammatory responses as indicated by increased numbers of T- and B-lymphocytes, regulatory T-cells, neutrophils, as well as apoptotic cells in the colon mucosa. Strikingly, C. jejuni infection also induced a pronounced influx of immune cells into extra-intestinal sites such as liver, lung, and kidney. Furthermore, C. jejuni susceptible weaned mice harbored a different microbiota as compared to resistant adult animals. These results support the essential role of the microflora composition in CR against C. jejuni and demonstrate that infant mouse models resemble C. jejuni mediated immunopathogenesis including the characteristic self-limited enterocolitis in human campylobacteriosis. Furthermore, potential clinical and immunological sequelae of chronic C. jejuni carriers in humans can be further elucidated by investigation of long-term infected infant mice. The observed extraintestinal disease manifestations might help to unravel the mechanisms causing complications such as reactive arthritis or Guillain-Barré syndrome.

4.
Eur J Microbiol Immunol (Bp) ; 2(3): 192-200, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24688765

RESUMO

In experimental models of and humans with intestinal inflammation, increased levels of the matrix-degrading gelatinases MMP-2 and -9 in inflamed tissues can be detected. The synthetic collagen analogue (Gly-Pro-Hyp)10, (GPO)10, has been identified as a relevant binding structure for proMMP-2/-9 and promotes enzymatic activity of proMMP-2. Since targeted MMP strategies might offer promising anti-inflammatory treatment options, we for the first time studied in vivo actions exerted by (GPO)10 applying an acute dextrane sulfate sodium (DSS) induced colitis model. Seven-day intraperitoneal (GPO)10 treatment ameliorated clinical symptoms and histopathological colonic changes as compared to placebo controls with severe colitis. (GPO)10-treated mice displayed a diminished influx of neutrophils, and T- and B-lymphocytes into their colonic mucosa whereas numbers of regulatory T-cells and regenerative cells were higher as compared to placebo controls. Furthermore, IL-6 secretion was down-regulated in ex vivo colonic biopsies derived from (GPO)10-treated mice whereas higher concentrations of the anti-inflammatory cytokine IL-10 in extra-intestinal compartments such as MLN and spleen could be detected. Strikingly, influx of inflammatory cells into lungs was abolished following (GPO)10 application. We therefore propose (GPO)10 as a promising effective and safe treatment option of intestinal and extra-intestinal inflammatory conditions in humans.

5.
Eur J Microbiol Immunol (Bp) ; 2(3): 210-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24688768

RESUMO

Campylobacter jejuni is one of the predominant causes for foodborne bacterial infections worldwide. We investigated whether signaling of C. jejuni-lipoproteins and -lipooligosaccharide via Toll-like-receptor (TLR) -2 and -4, respectively, is inducing intestinal and extra-intestinal immune responses following infection of conventional IL-10(-/-) mice with chronic colitis. At day 3 following oral infection, IL-10(-/-) mice lacking TLR-2 or TLR-4 harbored comparable C. jejuni strain ATCC 43431 loads in their colon. Interestingly, infected TLR-4(-/-) IL-10(-/-) mice displayed less compromized epithelial barrier function as indicated by lower translocation rates of live gut commensals into mesenteric lymphnodes (MLNs), and exhibited less distinct B lymphocyte responses in their colonic mucosa as compared to naїve IL-10(-/-) controls. Furthermore, in extra-intestinal compartments such as MLNs and spleens, abundance of myeloid cells was less distinct whereas relative percentages of activated T helper cells and cytotoxic T cells were higher in spleens and dendritic cells more abundant in MLNs of infected IL-10(-/-) animals lacking TLR-4 as compared to IL-10(-/-) controls. Taken together, in conventionally colonized IL-10(-/-) mice, TLR-4, but not TLR-2, is involved in mediating extra-intestinal pro-inflammatory immune responses following C. jejuni infection. Thus, conventional IL-10(-/-) mice are well suited to further dissect mechanisms underlying Campylobacter infections in vivo.

6.
Eur J Microbiol Immunol (Bp) ; 1(3): 237-48, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24516730

RESUMO

Enterocolitis caused by Campylobacter jejuni-infections represents an important socioeconomic burden worldwide. Recent results from novel murine infection models reveal that the intestinal microbiota is essential for maintaining colonization resistance against C. jejuni. We extended these studies to investigate the role of nutrition and obesity in susceptibility to C. jejuni-infection. Gnotobiotic (GB) mice generated by antibiotic treatment, which were fed with a human cafeteria diet (CAF), as well as obese (ob/ob) mice with a conventional microbiota harbored higher Escherichia coli loads in their colon as compared to respective controls. Following oral infection, C. jejuni 43431 ATCC readily colonized the intestines of CAF and ob/ob mice, whereas GB mice fed with a standard chow (MUD) eradicated the pathogen within days. Furthermore, live C. jejuni translocated into mesenteric lymph nodes of CAF, but not MUD mice. Strikingly, stably infected animals developed enterocolitis as indicated by increased numbers of immune and apoptotic cells in the colon in situ. We conclude that a specific human diet and obesity render mice susceptible to C. jejuni infection. The corresponding murine models are excellently suited for the study of C. jejuni pathogenesis and will help to get further insights into interplays between C. jejuni, microbiota, diet, obesity and immunity.

7.
Clin Microbiol Infect ; 16(6): 767-73, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19694763

RESUMO

Infective endocarditis is a rare but life-threatening disease associated with high mortality. Early diagnosis of the causative microorganism is critical to patient outcome. However, conventional diagnostic methods are often unsatisfactory in achieving this goal. As a proof of concept, we applied fluorescence in situ hybridization (FISH) for detection and identification of bacteria in histological sections of heart valves. Biopsy specimens from 54 suspected endocarditis patients were obtained during valve surgery and analysed via FISH. Specimens were screened with a probe panel that identifies the most common bacteria implicated in endocarditis. Results were compared with those of culture-based diagnostics and clinical data. Discrepant results were subjected to comparative sequence analysis of PCR-amplified 16S rRNA genes. FISH detected bacteria in 26 of the 54 heart valves. FISH allowed successful diagnosis of infective endocarditis in five of 13 blood culture-negative cases and in 11 of 37 valve culture-negative cases, showing the bacteria within their histological context. This technique allows the simultaneous detection and identification of microorganisms at the species or genus level directly from heart valves and might be a valuable tool for diagnosis of endocarditis.


Assuntos
Bactérias/classificação , Bactérias/isolamento & purificação , Técnicas Bacteriológicas/métodos , Endocardite Bacteriana/diagnóstico , Hibridização in Situ Fluorescente/métodos , Bactérias/genética , Biópsia , Valvas Cardíacas/microbiologia , Histocitoquímica , Humanos , Projetos Piloto , Sensibilidade e Especificidade
8.
Gut ; 56(7): 941-8, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17255219

RESUMO

BACKGROUND: In the course of inflammatory bowel diseases (IBD) and acute murine ileitis following peroral Toxoplasma gondii infection, commensal Escherichia coli accumulate at inflamed mucosal sites and aggravate small intestinal immunopathology. AIM: To unravel the molecular mechanisms by which commensal E coli exacerbate ileitis. METHODS: Ileitis was investigated in mice that lack Toll-like receptors (TLR) 2 or 4, specific for bacterial lipoproteins (LP) or lipopolysaccharide (LPS), respectively. Gnotobiotic mice, in which any cultivable gut bacteria were eradicated by antibiotic treatment, were used to study the role of LPS in ileitis. RESULTS: Microbiological analyses revealed that E coli increase in the inflamed ileum. TLR4(-/-), but not TLR2(-/-), mice displayed reduced mortality and small intestinal immunopathology. Decreased interferon (IFN)-gamma and nitric oxide (NO) levels in the inflamed terminal ileum of TLR4(-/-) mice indicated that TLR4 signalling aggravates ileitis via local mediator release from immune cells. E coli strains isolated from the inflamed ileum activated cultured mouse macrophages and induced TLR4-dependent nuclear factor kappaB activation and NO production in human embryonic kidney 293 cells and in peritoneal macrophages, respectively. Most strikingly, in contrast with wild-type mice, gnotobiotic TLR4(-/-) mice were protected from induction of ileitis by treatment with purified E coli lipid A or colonisation with live E coli. Finally, prophylactic treatment with the LPS scavenger polymyxin B ameliorated T gondii-induced ileitis. CONCLUSION: These findings highlight the innate immune system as a key player in T gondii-induced ileal immunopathology. Treatment with LPS or TLR4 antagonists may represent a novel strategy for prophylaxis and/or therapy of small intestinal inflammation in IBD.


Assuntos
Escherichia coli/patogenicidade , Ileíte/imunologia , Lipopolissacarídeos/imunologia , Receptor 4 Toll-Like/imunologia , Toxoplasmose/imunologia , Animais , Antibacterianos/uso terapêutico , Translocação Bacteriana/imunologia , Células Cultivadas , Contagem de Colônia Microbiana , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/imunologia , Vida Livre de Germes , Ileíte/tratamento farmacológico , Ileíte/microbiologia , Ileíte/parasitologia , Íleo/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Polimixina B/uso terapêutico , Transdução de Sinais/imunologia , Receptor 2 Toll-Like/deficiência , Receptor 4 Toll-Like/deficiência
10.
Genes Immun ; 6(5): 448-51, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15875057

RESUMO

Periodontitis is an inflammatory disease affecting the connective tissue surrounding the teeth leading to tooth loss. Pathogens associated with periodontitis interact with Toll-like receptors (TLRs) to induce cytokines causing and aggravating disease. We screened 197 individuals suffering from generalized periodontitis for the presence of Asp299Gly and Thr399Ile of TLR-4 as well as Arg753Gln of TLR-2 in comparison to matched controls. Single-nucleotide polymorphisms (SNPs) of TLR-4 were elevated among patients (odd's ratio 3.650, 95% CI 1.573-8.467, P < or = 0.0001), while no difference was observed for TLR-2. TLR-4 SNPs were correlated with chronic periodontitis (odd's ratio 5.562, 95% CI 2.199-14.04, P < or = 0.0001), but not with aggressive periodontitis. This observation was confirmed employing a group of periodontally healthy probands over 60 years of age. These data demonstrate that genetic variants of TLR-4 may act as risk factors for the development of generalized chronic periodontitis in humans.


Assuntos
Substituição de Aminoácidos/genética , Periodontite/genética , Polimorfismo de Nucleotídeo Único , Receptor 4 Toll-Like/genética , Adulto , Idoso , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
J Clin Microbiol ; 43(4): 1928-9, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15815021

RESUMO

Commercially available nucleic acid probe- and amplification-based systems for detection and differentiation of mycobacteria are widely used in clinical microbiology laboratories. Here we report two cases of human leprosy in which the COBAS AMPLICOR Mycobacterium intracellulare test led to false- positive results. Correct identification of Mycobacterium leprae was possible only by amplification and comparative sequence analysis of the 16S rRNA gene.


Assuntos
Erros de Diagnóstico , Hanseníase/diagnóstico , Complexo Mycobacterium avium/classificação , Mycobacterium leprae/classificação , Adulto , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , Reações Falso-Positivas , Humanos , Hanseníase/microbiologia , Masculino , Pessoa de Meia-Idade , Complexo Mycobacterium avium/genética , Complexo Mycobacterium avium/isolamento & purificação , Infecção por Mycobacterium avium-intracellulare/diagnóstico , Infecção por Mycobacterium avium-intracellulare/microbiologia , Mycobacterium leprae/genética , Mycobacterium leprae/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Kit de Reagentes para Diagnóstico , Análise de Sequência de DNA
12.
Int J Syst Evol Microbiol ; 54(Pt 4): 1117-1122, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15280279

RESUMO

So far, little phenotypic heterogeneity has been detected in cultured oral treponemes with trypsin-like proteolytic activity, and all have been assigned to the species Treponema denticola. However, comparisons of protein patterns and antigen expression in our collection of proteolytic oral treponemes occasionally identified isolates with a unique phenotype; e.g. strain OMZ 830 (=ATCC 700768), which qualified as a 'pathogen-related oral spirochaete' due to the presence of a approximately 37 kDa protein reactive with the Treponema pallidum FlaA-specific mAb H9-2. In addition to such single isolates, a homogeneous group of seven independent strains is described that were highly motile, medium-sized, proteolytic but asaccharolytic spirochaetes and were cultured from human gingivitis, periodontitis and acute necrotizing ulcerative gingivitis in medium OMIZ-Pat supplemented with 1% human serum and antibiotics. Growth of these spirochaetes in OMIZ-Pat was not dependent on, but was stimulated by, human or bovine serum. Carbohydrates were neither required nor stimulatory for growth. The protein and antigen patterns of total cell extracts of these organisms separated by SDS-PAGE were distinct from those of all previously cultured spirochaetes, with highest similarity to T. denticola. The novel spirochaete has a 2 : 4 : 2 arrangement of the periplasmic flagella, similar to T. denticola. However, the flagellin pattern as detected by immunostaining or glycan staining of Western blots readily distinguished the novel group from T. denticola. Also, distinct from reference strains of T. denticola, none of the novel isolates displayed sialidase or dentilisin activities, both of which are expressed by most strains of T. denticola. Trypsin-like activity and other enzymes as detected by API ZYM test were similar to those of T. denticola. The status of a novel species is supported by the 16S rRNA gene sequence, with 98.5% similarity to its closest cultured relative, T. denticola. The name Treponema putidum sp. nov. is proposed (type strain OMZ 758T=ATCC 700334T=CIP 108088T).


Assuntos
Gengivite Ulcerativa Necrosante/microbiologia , Periodontite/microbiologia , Treponema/classificação , Treponema/isolamento & purificação , Antígenos de Bactérias/análise , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/análise , Proteínas de Bactérias/imunologia , Metabolismo dos Carboidratos , Quimotripsina/metabolismo , Meios de Cultura/química , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , Flagelos/química , Flagelos/imunologia , Flagelina/análise , Flagelina/imunologia , Genes de RNAr , Humanos , Dados de Sequência Molecular , Movimento , Neuraminidase/metabolismo , Peptídeo Hidrolases/metabolismo , Filogenia , Proteínas/metabolismo , Proteoma , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência , Sacarose/metabolismo , Treponema/citologia , Treponema/fisiologia
13.
Clin Oral Implants Res ; 12(6): 543-51, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11737097

RESUMO

Bacterial adhesion on titanium implant surfaces has a strong influence on healing and long-term outcome of dental implants. Parameters like surface roughness and chemical composition of the implant surface were found to have a significant impact on plaque formation. The purpose of this study was to evaluate the influence of two physical hard coatings on bacterial adhesion in comparison with control surfaces of equivalent roughness. Two members of the oral microflora, Streptococcus mutans and Streptococcus sanguis were used. Commercially pure titanium discs were modified using four different surface treatments: physical vapour deposition (PVD) with either titanium nitride (TiN) or zirconium nitride (ZrN), thermal oxidation and structuring with laser radiation. Polished titanium surfaces were used as controls. Surface topography was examined by SEM and estimation of surface roughness was done using a contact stylus profilometer. Contact angle measurements were carried out to calculate surface energy. Titanium discs were incubated in the respective bacterial cell suspension for one hour and single colonies formed by adhering bacteria were counted by fluorescence microscopy. Contact angle measurements showed no significant differences between the surface modifications. The surface roughness (Ra) of all surfaces examined was between 0.14 and 1.00 microm. A significant reduction of the number of adherent bacteria was observed on inherently stable titanium hard materials such as TiN and ZrN and thermically oxidated titanium surfaces compared to polished titanium. In conclusion, physical modification of titanium implant surfaces such as coating with TiN or ZrN may reduce bacterial adherence and hence improve clinical results.


Assuntos
Materiais Revestidos Biocompatíveis , Implantes Dentários/microbiologia , Placa Dentária/microbiologia , Aderência Bacteriana , Humanos , Lasers , Microscopia Eletrônica de Varredura , Óxidos , Saliva , Estatísticas não Paramétricas , Streptococcus mutans/fisiologia , Streptococcus sanguis/fisiologia , Propriedades de Superfície , Titânio/efeitos da radiação , Molhabilidade , Zircônio
14.
Biologicals ; 29(2): 59-66, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11580210

RESUMO

Different procedures are available to inactivate bacteria and fungi, including their spores, as well as viruses in human bone transplants. The most efficient methods are considered to be gamma irradiation and thermal inactivation as well as chemical sterilization methods like the peracetic acid-ethanol treatment (PES). Following national and international standards or draft standards, the antimicrobial effectiveness of this procedure was evaluated. Due to the standardizable size as well as the clinical relevance, defatted human spongiosa cuboids (15x15x15 mm) served as model system. After treatment with PES for 2 and 4 hours, respectively, the titre of living micro-organisms was determined in the supernatant and the cuboid. A reduction in the titre of viable micro-organisms below the detection level (reduction factor >5 log10) was already achieved after an incubation time of 2 hours (Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Bacillus subtilis, Clostridium sporogenes, Mycobacterium terrae, Candida albicans as well as spores of Bacillus subtilis). No viable micro-organisms could be detected in any of the PES-treated test cuboids. Spores of Aspergillus niger were also completely inactivated. The PES procedure proved to be a reliable method for the sterilization of human bone transplants derived from spongiosa.


Assuntos
Transplante Ósseo/métodos , Esterilização/métodos , Bactérias/efeitos dos fármacos , Osso e Ossos/microbiologia , Etanol , Fungos/efeitos dos fármacos , Humanos , Técnicas In Vitro , Ácido Peracético , Esporos Fúngicos/efeitos dos fármacos , Esterilização/normas , Transplante Homólogo
15.
Int J Syst Evol Microbiol ; 51(Pt 5): 1653-1661, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11594592

RESUMO

Three facultatively anaerobic, Gram-positive bacteria, strains Se-3111T, Se-13111 and Se-1311A, were isolated from an anaerobic, dechlorinating bioreactor culture enriched from sediment of the River Saale in Germany. All strains were isolated from the dechlorinating mixed culture through their ability to reduce selenate anaerobically to elemental selenium. All three strains shared identical 16S rDNA sequences and phylogenetic analysis revealed that strain Se-3111T forms a novel taxon within the suborder Micrococcineae of the class Actinobacteria, related most closely to Beutenbergia cavernae. On the basis of genotypic, chemotaxonomic and physiological characteristics, it is proposed that the novel strains Se-3111T, Se-13111 and Se-1311A be classified in a new genus as Salana multivorans gen. nov., sp. nov. The type strain of the novel species is Se-3111T (= DSM 13521T = NRRL B-24118T).


Assuntos
Actinobacteria/classificação , Actinobacteria/crescimento & desenvolvimento , Reatores Biológicos , Compostos de Selênio/metabolismo , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Anaerobiose , Parede Celular/química , Meios de Cultura , DNA Bacteriano/análise , DNA Bacteriano/genética , DNA Ribossômico/análise , DNA Ribossômico/genética , Sedimentos Geológicos/microbiologia , Lipídeos/análise , Dados de Sequência Molecular , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Ribotipagem , Ácido Selênico , Análise de Sequência de DNA
16.
Int J Syst Evol Microbiol ; 51(Pt 4): 1257-1265, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11491321

RESUMO

A novel Bordetella species was isolated from an anaerobic, dechlorinating bioreactor culture enriched from river sediment. The only strain, Se-1111R(T) (= DSM 12804T = CCUG 43448T), for which the name Bordetella petrii is proposed, is designated the type strain of the novel species. Strain Se-1111R(T) was isolated from the dechlorinating mixed culture due to its ability to anaerobically reduce selenate to elemental selenium. Comparative 16S rDNA sequence analysis showed a close relationship between Se-1111R(T) and members of the genus Bordetella within the beta-Proteobacteria. This close phylogenetic relatedness was also reflected in several metabolic properties of Se-1111R(T), including its incapacity to utilize carbohydrates, by the high G+C content (63.8 mol%) of its DNA and by the presence of Q-8 as the major isoprenoid quinone. DNA-DNA hybridization experiments with type strains of all species of the genus Bordetella and closely related species Achromobacter xylosoxidans subsp. denitrificans provided further evidence for the assignment of strain Se-1111R(T) as a novel species of the genus Bordetella. This genus currently consists of seven aerobic species, all of which are known to occur in close pathogenic, opportunistic or possibly commensal relationships with various host organisms. B. petrii is the first member of this genus isolated from the environment and capable of anaerobic growth. The proposal of the novel species and an emended description of the genus Bordetella is presented.


Assuntos
Bordetella/classificação , Bordetella/isolamento & purificação , Anaerobiose , Composição de Bases , Sequência de Bases , Reatores Biológicos , Bordetella/genética , Bordetella/metabolismo , Clorobenzenos/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/genética , Genes Bacterianos , Sedimentos Geológicos/microbiologia , Microscopia Eletrônica , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Ácido Selênico , Compostos de Selênio/metabolismo , Terminologia como Assunto
17.
FEMS Microbiol Lett ; 201(2): 169-76, 2001 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-11470357

RESUMO

The proteolytic activity of 11 treponemal strains representing different phylogenetic groups was investigated by SDS-polyacrylamide gel electrophoresis with copolymerised casein, gelatin and fibrinogen as substrates. The activity was specified to be trypsin- and chymotrypsin-like by the cleavage of synthetic substrates BAPNA and SAAPFNA, respectively. Nine strains degrade casein and the synthetic substrate BAPNA. Chymotrypsin-like activity specifically inhibited by phenylmethylsulfonyl fluoride was found in four treponemes. Southern blot analysis using a Treponema socranskii subsp. socranskii-specific prtP probe confirmed the presence of prtP homologous genes in these four strains. The internal fragments of the chymotrypsin-like protease genes were cloned and sequenced after PCR amplification. Here we report the cloning of the complete prtP-like gene of T. socranskii subsp. socranskii, an organism shown to possess epidemiologic relevance in periodontitis.


Assuntos
Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Treponema/enzimologia , Treponema/genética , Southern Blotting , Quimotripsina/química , Clonagem Molecular , Gelatinases/genética , Gelatinases/metabolismo , Genes Bacterianos/genética , Hidrólise , Dados de Sequência Molecular , Periodontite/microbiologia , Filogenia , Reação em Cadeia da Polimerase , Serina Endopeptidases/química , Especificidade por Substrato , Treponema/classificação , Treponema/metabolismo , Tripsina/química
18.
Infection ; 29(3): 113-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11440380

RESUMO

BACKGROUND: Chlamydia trachomatis is considered to be the most common sexually transmitted disease in Germany. It is currently unclear whether chlamydial infection causes pathological conditions of the male accessory glands with consequences for male infertility. PATIENTS AND METHODS: Within the framework of several prospective studies the association between sperm quality, male accessory gland function and infection with C. trachomatis was investigated in men of couples with unexplained infertility. Chlamydial infection was determined by serologic methods and by proof of Chlamydia-specific DNA. As a marker of infection the direct determination of granulocytes in the ejaculate or the measurement of the polymorphonuclear (PMN) elastase concentration was used. The male accessory gland function was evaluated using the markers fructose, citric acid and alpha-glucosidase in the seminal plasma. RESULTS: Chlamydia-specific DNA in the ejaculate was present in between 3-5% of the subjects, which corresponds to its prevalence in the normal population. Chlamydia IgA antibodies were demonstrated with a frequency of 38% in seminal plasma (n = 834) using a genus-specific test (rELISA). Using other species-specific tests (MIF, SeroCT, IgA pELISA and ImmunoComb), Chlamydia IgA antibodies were found at frequencies of between 8 and 22%. CONCLUSION: Only in a few individual cases was it possible to show a connection between reduced sperm quality, disturbed male accessory gland function and indication of infection with Chlamydia, bacteria or Ureaplasma.


Assuntos
Infecções por Chlamydia/diagnóstico , Chlamydia trachomatis/imunologia , Infertilidade Masculina/microbiologia , Espermatozoides/fisiologia , Adulto , Anticorpos Antibacterianos/análise , Infecções por Chlamydia/complicações , Infecções por Chlamydia/imunologia , Chlamydia trachomatis/patogenicidade , Estudos Transversais , DNA Bacteriano/análise , Ensaio de Imunoadsorção Enzimática , Doenças dos Genitais Masculinos/complicações , Doenças dos Genitais Masculinos/diagnóstico , Doenças dos Genitais Masculinos/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Sêmen/microbiologia
19.
FEMS Microbiol Lett ; 197(2): 187-93, 2001 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-11313133

RESUMO

We recently cloned the major outer membrane protein of Treponema maltophilum [Heuner, K., Choi, B.K., Schade, R., Moter, A., Otto, A., Göbel, U.B., J. Bacteriol. 181, 1025-1029]. Here we report the localization of the major sheath protein (Msp)A protein in T. maltophilum by immunogold electron microscopy and its expression. Northern blot analysis revealed that mspA is expressed constitutively as a monocistronic unit. The transcription initiation site of the mspA gene was identified by primer extension analysis. A further screening of a genomic library of T. maltophilum with an anti-outer membrane fraction antibody was done. We were able to clone DNA regions of T. maltophilum encoding putative sugar transport operons and putative outer membrane proteins of this oral treponeme which has a high prevalence in periodontal lesions.


Assuntos
Proteínas da Membrana Bacteriana Externa/análise , Proteínas de Bactérias/análise , Proteínas de Membrana/análise , Treponema/química , Proteínas da Membrana Bacteriana Externa/biossíntese , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Northern Blotting , Western Blotting , Metabolismo dos Carboidratos , Escherichia coli/genética , Vetores Genéticos , Biblioteca Genômica , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Microscopia Imunoeletrônica , Dados de Sequência Molecular , Óperon , RNA Bacteriano/análise , Proteínas Recombinantes/biossíntese , Transformação Genética , Treponema/genética
20.
J Biol Chem ; 276(25): 22041-7, 2001 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-11285258

RESUMO

Recently Toll-like receptors (TLRs) have been found to be involved in cellular activation by microbial products, including lipopolysaccharide, lipoproteins, and peptidoglycan. Although for these ligands the specific transmembrane signal transducers TLR-4, TLR-2, or TLR-2 and -6 have now been identified, the molecular basis of recognition of lipoteichoic acids (LTAs) and related glycolipids has not been completely understood. In order to determine the role of TLRs in immune cell activation by these stimuli, experiments involving TLR-2-negative cell lines, TLR-expression plasmids, macrophages from TLR-4-deficient C3H/HeJ-mice, and inhibitory TLR-4/MD-2 antibodies were performed. Glycolipids from Treponema maltophilum and Treponema brennaborense, as well as highly purified LTAs from Staphylococcus aureus and Bacillus subtilis exhibited TLR-2 dependence in nuclear factor kappaB activation and cytokine induction; however, T. brennaborense additionally appeared to signal via TLR-4. Fractionation of the T. brennaborense glycolipids by hydrophobic interaction chromatography and subsequent cell stimulation experiments revealed two peaks of activity, one exhibiting TLR-2-, and a second TLR-4-dependence. Furthermore, we show involvement of the signaling molecules MyD88 and NIK in cell stimulation by LTAs and glycolipids by dominant negative overexpression experiments. In summary, the results presented here indicate that TLR-2 is the main receptor for Treponema glycolipid and LTA-mediated inflammatory response.


Assuntos
Proteínas de Drosophila , Glicolipídeos/metabolismo , Lipopolissacarídeos/metabolismo , Glicoproteínas de Membrana/fisiologia , NF-kappa B/metabolismo , Receptores de Superfície Celular/fisiologia , Ácidos Teicoicos/metabolismo , Treponema/metabolismo , Animais , Linhagem Celular , Interleucina-6/biossíntese , Camundongos , Transporte Proteico , Receptor 2 Toll-Like , Receptor 4 Toll-Like , Receptores Toll-Like
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