Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 65
Filter
1.
BMC Infect Dis ; 17(1): 584, 2017 08 23.
Article in English | MEDLINE | ID: mdl-28835212

ABSTRACT

BACKGROUND: It has been suggested that more than 100 bacterial species can be identified using only seven universal bacterial primer sets in the melting temperature (Tm) mapping method and that these findings can be obtained within 3 h of sterile site collection. CASE PRESENTATION: A 67-year-old Japanese man with type 2 diabetes visited our hospital complaining of progressive lower back pain for 2 months. The patient was suspected to have spondylodiscitis on magnetic resonance imaging of the spine. Blood culture and transcutaneous vertebral biopsy were subsequently performed. Using the Tm mapping method, Parvimonas micra was detected from a transcutaneous vertebral biopsy specimen in 3 h. Gram-positive cocci were also detected by Gram staining and P. micra was identified directly from the anaerobic blood culture by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Four days after admission, the biopsy specimen culture isolate was identified as P. micra. CONCLUSIONS: The Tm mapping method may be useful for the diagnosis of bacterial infections where diagnosis is challenging because of the difficulty of culturing.


Subject(s)
Discitis/diagnosis , Gram-Positive Bacterial Infections/diagnosis , Peptostreptococcus/genetics , Aged , DNA Primers/chemistry , Diabetes Mellitus, Type 2/microbiology , Discitis/microbiology , Gram-Positive Bacterial Infections/microbiology , Humans , Magnetic Resonance Imaging , Male , Peptostreptococcus/isolation & purification , Peptostreptococcus/pathogenicity , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Spine/microbiology , Temperature
2.
Rev. esp. quimioter ; 30(4): 285-292, ago. 2017. tab
Article in English | IBECS | ID: ibc-164846

ABSTRACT

The clinical and microbiological characteristics of infections caused by Parvimonas micra is described, including 30 cases in the literature and a new case handled at the present centre. Out of the 31 patients, 18 were male; mean age at diagnosis was 65.1 ± 13.0 years. Infection site was the vertebral spine in 14 patients and joints and heart valves in 5 each one; pain was present in all patients with articular localization and in almost all patients with vertebral involvement. The diagnosis was obtained from fluid aspirate or drainage in 13 cases and blood cultures in 11. In 8 cases, molecular techniques were also applied. The most frequently used antimicrobials were clindamycin, penicillin, amoxicillin and ceftriaxone. The outcome was positive with the medical treatment in 28 patients. P. micra infections are uncommon and requires a high index of suspicion (AU)


Se describen las características clínicas y microbiológicas de las infecciones causadas por Parvimonas micra, incluyendo 30 casos revisados de la literatura y un nuevo caso tratado en nuestro centro. De los 31 pacientes, 18 eran hombres; la media de edad al diagnóstico fue de 65,1 ± 13,0 años. En 14 pacientes, la localización de la infección fue la columna vertebral, mientras que las articulaciones y las válvulas cardiacas lo fueron en 5 cada una; en todos los pacientes con localización articular hubo dolor, y en caso todos los pacientes con afectación vertebral. El diagnóstico se obtuvo mediante aspiración de líquido o drenaje en 13 casos y mediante hemocultivos en 11. En 8 casos se aplicaron técnicas moleculares. Los antimicrobianos más frecuentemente utilizados fueron clindamicina, penicilina, amoxicilina y ceftriaxona. El pronóstico fue favorable con el tratamiento médico en 28 pacientes. Las infecciones por P. micra son raras y requieren un alto índice de sospecha (AU)


Subject(s)
Humans , Male , Female , Middle Aged , Aged , Aged, 80 and over , Pleural Effusion/diagnosis , Pleural Effusion/drug therapy , Pleural Effusion/microbiology , Infections/drug therapy , Anti-Infective Agents/administration & dosage , Peptostreptococcus , Peptostreptococcus/isolation & purification , Spine , Spine/pathology , Clindamycin/therapeutic use , Penicillins/administration & dosage , Amoxicillin/administration & dosage , Ceftriaxone/administration & dosage , Peptostreptococcus/pathogenicity
5.
J Appl Oral Sci ; 24(2): 181-5, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27119767

ABSTRACT

Objective The aim of this study was to evaluate the association of Porphyromonas endodontalis, Filifactor alocis and Dialister pneumosintes with the occurrence of periodontitis. Material and Methods Thirty subjects with chronic periodontitis (ChP) and 10 with periodontal health (PH) were included in the study. Nine subgingival biofilm samples were collected as follows: i) PH group - from the mesial/buccal aspect of each tooth in two randomly chosen contralateral quadrants; ii) ChP group - from three sites in each of the following probing depth (PD) categories: shallow (≤3 mm), moderate (4-6 mm) and deep (≥7 mm). Checkerboard DNA-DNA hybridization was used to analyze the samples. Results We found the three species evaluated in a higher percentage of sites and at higher levels in the group with ChP than in the PH group (p<0.05, Mann-Whitney test). We also observed these differences when the samples from sites with PD≤4 mm or ≥5 mm of subjects with ChP were compared with those from subjects with PH (p<0.05, Mann-Whitney test). In addition, the prevalence and levels of D. pneumosintes, and especially of F. alocis were very low in healthy subjects (0.12x105 and 0.01x105, respectively). Conclusion F. alocis and D. pneumosintes might be associated with the etiology of ChP, and their role in the onset and progression of this infection should be further investigated. The role of P. endodontalis was less evident, since this species was found in relatively high levels and prevalence in the PH group.


Subject(s)
Chronic Periodontitis/microbiology , Peptostreptococcus/pathogenicity , Porphyromonas endodontalis/pathogenicity , Veillonellaceae/pathogenicity , Adult , Biofilms , Brazil , Case-Control Studies , Colony Count, Microbial , DNA Probes , DNA, Bacterial , Dental Plaque/microbiology , Female , Gingiva/microbiology , Humans , Male , Middle Aged , Peptostreptococcus/isolation & purification , Porphyromonas endodontalis/isolation & purification , Statistics, Nonparametric , Veillonellaceae/isolation & purification
6.
J. appl. oral sci ; 24(2): 181-185, Mar.-Apr. 2016. tab, graf
Article in English | LILACS | ID: lil-779905

ABSTRACT

ABSTRACT Objective The aim of this study was to evaluate the association of Porphyromonas endodontalis, Filifactor alocis and Dialister pneumosintes with the occurrence of periodontitis. Material and Methods Thirty subjects with chronic periodontitis (ChP) and 10 with periodontal health (PH) were included in the study. Nine subgingival biofilm samples were collected as follows: i) PH group - from the mesial/buccal aspect of each tooth in two randomly chosen contralateral quadrants; ii) ChP group - from three sites in each of the following probing depth (PD) categories: shallow (≤3 mm), moderate (4-6 mm) and deep (≥7 mm). Checkerboard DNA-DNA hybridization was used to analyze the samples. Results We found the three species evaluated in a higher percentage of sites and at higher levels in the group with ChP than in the PH group (p<0.05, Mann-Whitney test). We also observed these differences when the samples from sites with PD≤4 mm or ≥5 mm of subjects with ChP were compared with those from subjects with PH (p<0.05, Mann-Whitney test). In addition, the prevalence and levels of D. pneumosintes, and especially of F. alocis were very low in healthy subjects (0.12x105 and 0.01x105, respectively). Conclusion F. alocis and D. pneumosintes might be associated with the etiology of ChP, and their role in the onset and progression of this infection should be further investigated. The role of P. endodontalis was less evident, since this species was found in relatively high levels and prevalence in the PH group.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Peptostreptococcus/pathogenicity , Porphyromonas endodontalis/pathogenicity , Veillonellaceae/pathogenicity , Chronic Periodontitis/microbiology , Peptostreptococcus/isolation & purification , Brazil , DNA, Bacterial , Colony Count, Microbial , DNA Probes , Case-Control Studies , Statistics, Nonparametric , Biofilms , Porphyromonas endodontalis/isolation & purification , Dental Plaque/microbiology , Veillonellaceae/isolation & purification , Gingiva/microbiology
7.
J Emerg Med ; 50(5): e231-6, 2016 May.
Article in English | MEDLINE | ID: mdl-26994838

ABSTRACT

BACKGROUND: Pyometra is defined as an accumulation of purulent material in the uterine cavity. Spontaneous perforation is a very rare complication of pyometra. The clinical findings of perforated pyometra are similar to perforation of the gastrointestinal tract and other causes of acute abdomen. CASE REPORT: We report a rare and difficult case of peritonitis in an elderly female that was caused by a spontaneous perforation of pyometra. A 90-year-old postmenopausal woman was referred to our hospital with complaints of vomiting, fever, and abdominal pain. Computed tomography revealed a large amount of ascites, cystic mass in the uterus, and intraperitoneal and intrauterine air. Transvaginal ultrasound demonstrated a thin area around the fundus. An emergency laparotomy was performed for the suspected gastrointestinal perforation or perforation of pyometra. At laparotomy, copious purulent fluid was present in the peritoneal cavity; however, no perforation of the gastrointestinal tract was observed. We identified a perforation site over the uterine fundus and purulent material exuding from the cavity. Subsequently, hysterectomy and bilateral salpingo-oophorectomy were performed. The patient was discharged on postoperative day 13 with no complications. Histopathologic studies revealed endometritis and myometritis with no evidence of malignancy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: With diffuse peritonitis, ruptured pyometra should be considered, even in elderly female patients. This case illustrates the importance of clinical knowledge of acute gynecologic diseases. Here we also review the perforation of pyometra with no evidence of malignancy.


Subject(s)
Peritonitis/complications , Pyometra/complications , Spontaneous Perforation/complications , Abdominal Pain/etiology , Abdominal Pain/physiopathology , Aged, 80 and over , Ascites/etiology , Ascites/physiopathology , Emergency Service, Hospital/organization & administration , Escherichia coli/drug effects , Escherichia coli/pathogenicity , Female , Fever/etiology , Fever/physiopathology , Humans , Laparotomy/methods , Ovariectomy , Peptostreptococcus/drug effects , Peptostreptococcus/pathogenicity , Peritonitis/etiology , Peritonitis/physiopathology , Pyometra/mortality , Pyometra/physiopathology , Salpingectomy , Spontaneous Perforation/physiopathology , Ultrasonography/methods , Uterus/diagnostic imaging , Uterus/physiopathology , Vaginal Discharge/etiology , Vaginal Discharge/physiopathology , Vomiting/etiology , Vomiting/physiopathology
8.
Sci Rep ; 4: 6602, 2014 Oct 13.
Article in English | MEDLINE | ID: mdl-25308100

ABSTRACT

The oral microbiota change dramatically with each part of the oral cavity, even within the same mouth. Nevertheless, the microbiota associated with peri-implantitis and periodontitis have been considered the same. To improve our knowledge of the different communities of complex oral microbiota, we compared the microbial features between peri-implantitis and periodontitis in 20 patients with both diseases. Although the clinical symptoms of peri-implantitis were similar to those of periodontitis, the core microbiota of the diseases differed. Correlation analysis revealed the specific microbial co-occurrence patterns and found some of the species were associated with the clinical parameters in a disease-specific manner. The proportion of Prevotella nigrescens was significantly higher in peri-implantitis than in periodontitis, while the proportions of Peptostreptococcaceae sp. and Desulfomicrobium orale were significantly higher in periodontitis than in peri-implantitis. The severity of the peri-implantitis was also species-associated, including with an uncultured Treponema sp. that correlated to 4 clinical parameters. These results indicate that peri-implantitis and periodontitis are both polymicrobial infections with different causative pathogens. Our study provides a framework for the ecologically different bacterial communities between peri-implantitis and periodontitis, and it will be useful for further studies to understand the complex microbiota and pathogenic mechanisms of oral polymicrobial diseases.


Subject(s)
Microbiota/genetics , Peri-Implantitis/microbiology , Periodontitis/microbiology , Female , Humans , Male , Middle Aged , Mouth/microbiology , Mouth/pathology , Peptostreptococcus/genetics , Peptostreptococcus/isolation & purification , Peptostreptococcus/pathogenicity , Peri-Implantitis/genetics , Peri-Implantitis/pathology , Periodontitis/genetics , Periodontitis/pathology
10.
J Immunol ; 189(2): 850-9, 2012 Jul 15.
Article in English | MEDLINE | ID: mdl-22696444

ABSTRACT

To subvert host defenses, some microbial pathogens produce proteins that interact with conserved motifs in V regions of B cell Ag receptor shared by large sets of lymphocytes, which define the properties of a superantigen. Because the clonal composition of the lymphocyte pool is a major determinant of immune responsiveness, this study was undertaken to examine the in vivo effect on the host immune system of exposure to a B cell superantigen, protein L (PpL), a product of the common commensal bacterial species, Finegoldia magna, which is one of the most common pathogenic species among Gram-positive anaerobic cocci. Libraries of Vκ L chain transcripts were generated from the spleens of control and PpL-exposed mice, and the expressed Vκ rearrangements were characterized by high-throughput sequencing. A total of 120,855 sequencing reads could be assigned to a germline Vκ gene, with all 20 known Vκ subgroups represented. In control mice, we found a recurrent and consistent hierarchy of Vκ gene usage, as well as patterns of preferential Vκ-Jκ pairing. PpL exposure induced significant targeted global shifts in repertoire with reduction of Vκ that contain the superantigen binding motif in all exposed mice. We found significant targeted reductions in the expression of clonotypes encoded by 14 specific Vκ genes with the predicted PpL binding motif. These rigorous surveys document the capacity of a microbial protein to modulate the composition of the expressed lymphocyte repertoire, which also has broad potential implications for host-microbiome and host-pathogen relationships.


Subject(s)
Antigens, Bacterial/immunology , B-Lymphocyte Subsets/immunology , B-Lymphocyte Subsets/microbiology , Gene Rearrangement, B-Lymphocyte/immunology , Immunoglobulin Variable Region/metabolism , Immunoglobulin kappa-Chains/metabolism , Superantigens/immunology , Animals , Antigens, Bacterial/biosynthesis , Antigens, Bacterial/metabolism , B-Lymphocyte Subsets/metabolism , Bacterial Proteins/immunology , Bacterial Proteins/metabolism , DNA-Binding Proteins/immunology , DNA-Binding Proteins/metabolism , Gene Rearrangement, B-Lymphocyte/genetics , Immunoglobulin Variable Region/immunology , Immunoglobulin kappa-Chains/immunology , Mice , Mice, Inbred C57BL , Peptostreptococcus/immunology , Peptostreptococcus/metabolism , Peptostreptococcus/pathogenicity , Superantigens/biosynthesis , Superantigens/metabolism , Virulence/immunology
11.
Antimicrob Agents Chemother ; 56(6): 3448-52, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22391542

ABSTRACT

We evaluated the activity of CB-183,315 against Clostridium difficile, including strains that are resistant to fluoroquinolones and metronidazole and with elevated MICs to vancomycin as well as other Gram-positive intestinal pathogens. The MICs of CB-183,315 against all C. difficile isolates were ≤ 1 µg/ml. CB-183,315 had greater activity than vancomycin and metronidazole against C. difficile isolates and was more active than the comparators against vancomycin-resistant enterococcus (VRE). CB-183,315 also had excellent activity against methicillin-resistant Staphylococcus aureus (MRSA), other Clostridium spp., and Peptostreptococcus spp.


Subject(s)
Anti-Bacterial Agents/pharmacology , Clostridioides difficile/drug effects , Intestines/microbiology , Lipopeptides/pharmacology , Vancomycin/pharmacology , Clostridioides difficile/pathogenicity , Drug Resistance, Multiple, Bacterial , Enterococcus/drug effects , Enterococcus/pathogenicity , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Metronidazole/pharmacology , Microbial Sensitivity Tests , Peptostreptococcus/drug effects , Peptostreptococcus/pathogenicity
12.
Phytother Res ; 23(10): 1449-52, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19277973

ABSTRACT

Recent studies brought evidence regarding the potential beneficial effects of cranberry polyphenols for periodontal infections. In this study, we evaluated the capacity of a proanthocyanidin-rich cranberry fraction to protect macrophages and oral epithelial cells against cytotoxicity induced by bacterial components. U937 cells, differentiated into adherent macrophage-like cells, as well as oral epithelial cells were treated with cell wall or lipopolysaccharide preparations from periodontopathogens. Cell viability was monitored using a commercial MTT (3-[4,5-diethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. The cytoprotective effect was evaluated by pre-incubating human cells with a proanthocyanidin-rich cranberry fraction prior to treatment with the bacterial components at toxic concentrations. Among the various bacterial components tested, Peptostreptotoccus micros cell wall was found to be the most toxic for macrophages and epithelial cells and was thus selected for further analyses. Treatment of monocyte-derived macrophages with cell wall of P. micros (20 microg/ml) decreased the cell viability by approximately 50%. Adding the cranberry fraction prior to treating cells with P. micros cell wall dose-dependently protected monocyte-derived macrophages from the toxic effect. A dose-dependent cytoprotective effect of the cranberry fraction was also observed with oral epithelial cells treated with P. micros cell wall. This study suggests that cranberry polyphenols may exert a protective effect for host cells against the toxicity induced by bacterial components.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Toxins/antagonists & inhibitors , Epithelial Cells/drug effects , Macrophages/drug effects , Plant Preparations/pharmacology , Proanthocyanidins/pharmacology , Vaccinium macrocarpon/chemistry , Bacteria/pathogenicity , Bacterial Structures/pathogenicity , Cell Line , Cell Survival/drug effects , Cell Wall/microbiology , Dose-Response Relationship, Drug , Epithelial Cells/microbiology , Fruit , Humans , Lipopolysaccharides , Macrophages/microbiology , Mouth , Peptostreptococcus/pathogenicity , Protective Agents/pharmacology , U937 Cells
13.
An. med. interna (Madr., 1983) ; 25(5): 226-228, mayo 2008. tab
Article in Es | IBECS | ID: ibc-66832

ABSTRACT

Describimos dos nuevos casos de endocarditis por Peptostreptococcus, uno de ellos sobre válvula protésica y causado por P. micros, y otro caso de endocarditis tricuspídea por P. assacharolyticus en un paciente ADVP. Revisamos los 9 casos previamente publicados en la literatura de endocarditis causada por anaerobios del género Peptostreptococcus


We describe two new cases of Peptostreptococcus endocarditis, one case of Peptostreptococcus micros prosthetic valve endocarditis and the other of Peptostreptococcus assaccharolyticus tricuspid native valve endocarditis in an intravenous drug user (IDU) patient and review nine cases previously reported


Subject(s)
Humans , Male , Female , Middle Aged , Adult , Endocarditis/diagnosis , Endocarditis/epidemiology , Peptostreptococcus/isolation & purification , Peptostreptococcus/pathogenicity , Penicillins/therapeutic use , Aneurysm, Infected/complications , Aneurysm, Infected/diagnosis , Endocarditis/pathology , Mitral Valve/abnormalities , Mitral Valve/pathology , Mitral Valve Insufficiency/complications , Esophagus/pathology , Esophagus , Gram-Negative Anaerobic Cocci/isolation & purification , Endocarditis/complications , Endocarditis, Bacterial/complications
15.
J Endotoxin Res ; 13(4): 219-26, 2007.
Article in English | MEDLINE | ID: mdl-17956940

ABSTRACT

Peptostreptococcus micros is a Gram-positive anaerobic bacterium associated with periodontitis, a chronic inflammatory disease affecting tooth-supporting tissues. In the present study, we investigated the response of human macrophages to stimulation with a cell wall preparation from P. micros. In addition, the effect of the preparation on the phosphorylation of macrophage kinases was studied. The preparation, which was non-toxic for macrophages, significantly increased the secretion of the pro-inflammatory cytokines TNF-alpha, IL-1beta and IL-6. It also increased the secretion of two potent chemokines IL-8 and, to a lesser extent, RANTES. Lastly, stimulation of macrophages by the P. micros cell wall preparation induced a significant increase in MMP-9 secretion but had no effect on the production of prostaglandin E2. The phosphorylation of macrophage kinases, including cAMP-dependent protein-serine kinase (PKA) catalytic subunit beta, G protein-coupled receptor-serine kinase 2, mitogen-activated protein-serine kinase p38 alpha (p38a MAPK), extracellular regulated protein-serine kinase 2 (ERK2) and Jun N-terminus protein-serine kinases (JNK), increased following stimulation with cell wall. In summary, our study showed that the P. micros cell wall preparation induced intracellular signaling pathways, leading to an increased production of pro-inflammatory cytokines, chemokines and MMP-9 by macrophages.


Subject(s)
Cell Wall/microbiology , Inflammation/microbiology , Macrophages/microbiology , Peptostreptococcus/pathogenicity , Cell Survival , Gram-Negative Bacterial Infections/physiopathology , Humans , Macrophages/enzymology , Macrophages/pathology , Protein Kinases/metabolism
17.
J Periodontol ; 76(2): 289-94, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15974855

ABSTRACT

BACKGROUND: Actinobacillus actinomycetemcomitans is considered a major etiologic agent of aggressive periodontitis (AgP). Other periodontopathic bacteria such as Porphyromonas gingivalis are also suspected of participating in aggressive periodontitis although the evidence to support this is controversial. The aim of the present study was to determine the prevalence of eight periodontopathic bacteria in Chilean patients with AgP. METHODS: Subgingival plaque samples were collected from 36 aggressive, 30 localized, and six generalized periodontitis patients. Samples from 17 advanced chronic periodontitis (CP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in prereduced transport fluid (RTF) and cultured. Periodontal bacteria were primarily identified by colony morphology under stereoscopic microscope and rapid biochemical tests. The identity of some bacterial isolates was confirmed by colony polymerase chain reaction (PCR). RESULTS: AgP showed a significatively higher prevalence of C. rectus than CP (P = 0.036). The only statistical difference found was for C. rectus. Patients with AgP showed a higher, but not statistically significant, prevalence of P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. A similar prevalence in both groups of patients was observed for F. nucleatum and P. intermedia/nigrescens, and A. actinomycetemcomitans was less prevalent in AgP than CP patients. In localized AgP, P. intermedia/nigrescens, E. corrodens, F. nucleatum, and P. micros were the more prevalent pathogens in contrast to generalized AgP patients who harbored A. actinomycetemcomitans, P. gingivalis, and Capnocytophaga sp. as the most prevalent bacteria. CONCLUSIONS: C. rectus, P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. were the most predominant periodontopathic bacteria of AgP in this Chilean population, but the only statistical difference found here between AgP and CP was for C. rectus, suggesting that the differences in clinical appearance may be caused by factors other than the microbiological composition of the subgingival plaque of these patients. In this study, the prevalence of A. actinomycetemcomitans was much lower than that of P. gingivalis.


Subject(s)
Periodontitis/microbiology , Acute Disease , Adolescent , Adult , Aggregatibacter actinomycetemcomitans/isolation & purification , Aggregatibacter actinomycetemcomitans/pathogenicity , Campylobacter rectus/isolation & purification , Campylobacter rectus/pathogenicity , Capnocytophaga/isolation & purification , Capnocytophaga/pathogenicity , Chi-Square Distribution , Chronic Disease , Colony Count, Microbial , Cross-Sectional Studies , Dental Plaque/microbiology , Eikenella corrodens/isolation & purification , Eikenella corrodens/pathogenicity , Female , Fusobacterium nucleatum/isolation & purification , Fusobacterium nucleatum/pathogenicity , Humans , Male , Middle Aged , Peptostreptococcus/isolation & purification , Peptostreptococcus/pathogenicity , Porphyromonas gingivalis/isolation & purification , Porphyromonas gingivalis/pathogenicity , Prevotella intermedia/isolation & purification , Prevotella intermedia/pathogenicity , Prevotella nigrescens/isolation & purification , Prevotella nigrescens/pathogenicity
18.
Cell Microbiol ; 6(7): 609-23, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15186398

ABSTRACT

Protein L is an immunoglobulin (Ig)-binding protein produced by the Gram-positive bacterium Peptostreptococcus magnus that interacts with the variable region of Ig kappa light chains. The Ig light chain-binding capacity of protein L gives it the potential to interact with cells expressing surface Ig such as B cells. The present study was performed to address the in vivo trafficking of protein L at both the organ and the cellular level. Using the powerful technique of whole-body autoradiography in a murine model system, we demonstrate specific targeting of protein L to secondary lymphoid tissues in whole-animal analysis. The observed targeting depends on the capacity to interact with murine Ig, as tissue targeting was not apparent in mice given protein H, an Ig-binding protein produced by Streptococcus pyogenes with affinity for human but not murine Ig. Tissue targeting data were combined with flow cytometry analysis, which demonstrated the capacity of protein L to target and activate B lymphocytes in vivo. B cells targeted by protein L had increased surface expression of CD86 and MHC-II, and protein L was present in vacuolar compartments of B cells. Protein L did not bind T cells or natural killer cells but had some capacity to target dendritic cells and macrophages. The data show that protein L preferentially targets secondary lymphoid organs, and activates and is internalized by B cells in vivo. Furthermore, the observed tissue and cell targeting properties require an affinity for murine Ig. These data support the potential use of this Ig-binding protein as a targeting approach to deliver agents to defined cell populations in vivo.


Subject(s)
B-Lymphocytes/metabolism , Bacterial Proteins/metabolism , Lymph Nodes/immunology , Lymphocyte Activation/immunology , Spleen/immunology , Animals , Autoradiography/methods , B-Lymphocytes/immunology , Bacterial Proteins/chemistry , Binding Sites , Flow Cytometry , Iodine Radioisotopes/metabolism , Lymph Nodes/cytology , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Microscopy, Confocal , Peptostreptococcus/metabolism , Peptostreptococcus/pathogenicity , Spleen/cytology
19.
Infect Immun ; 72(6): 3515-23, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15155659

ABSTRACT

Some pathogens have evolved to produce proteins, called B-cell superantigens, that can interact with human immunoglobulin variable regions, independently of the combining site, and activate B lymphocytes that express the target immunoglobulins. However, the in vivo consequences of these interactions on human B-cell numbers and function are largely unknown. Using transgenic mice expressing fully human immunoglobulins, we studied the consequences of in vivo exposure of protein L of Peptostreptococcus magnus with human immunoglobulins. In the mature pool of B cells, protein L exposure resulted in a specific reduction of splenic marginal-zone B cells and peritoneal B-1 cells. Splenic B cells exhibited a skewed light-chain repertoire consistent with the capacity of protein L to bind specific kappa gene products. Remarkably, these two B-cell subsets are implicated in innate B-cell immunity, allowing rapid clearance of pathogens. Thus, the present study reveals a novel mechanism that may be used by some infectious agents to subvert a first line of the host's immune defense.


Subject(s)
B-Lymphocyte Subsets/immunology , Bacterial Proteins/immunology , Immunoglobulins/metabolism , Peptostreptococcus/pathogenicity , Superantigens/immunology , Animals , B-Lymphocyte Subsets/physiology , Bacterial Proteins/metabolism , Humans , Immunity, Innate , Immunoglobulin M/blood , Immunoglobulin kappa-Chains/metabolism , Immunoglobulins/genetics , Mice , Mice, Transgenic , Peptostreptococcus/metabolism , Spleen/cytology , Spleen/immunology
20.
Eur J Oral Sci ; 112(3): 207-15, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15154917

ABSTRACT

In six monkeys, 160 root canals were inoculated with a combination of four bacterial strains belonging to species Streptococcus milleri, Peptostreptococcus anaerobius, Prevotella oralis, and Fusobacterium nucleatum. In two other monkeys, 24 root canals were inoculated with a five-strain combination consisting of these strains and a strain of Enterococcus faecalis. All strains were previously isolated from an infected monkey root canal. After 8-12 months, survival of the strains was recorded bacteriologically, and the reaction in the periapical region was radiographed. From 180 of 184 root canals, one or more of the bacterial strains were reisolated. The two facultative strains were more frequently reisolated than the anaerobic strains. Apical periodontitis was registered in the periapical region of more than 96% of root canals with reisolated bacteria but in none of those without reisolated bacteria. Endodontic treatment was carried out in two sessions with an interval of 14 d without interappointment dressings, and the effect was evaluated bacteriologically before and after each treatment. The chemo-mechanical treatment reduced significantly the number of strains and bacterial cells. The facultative bacteria were more resistant to the treatment than the anaerobic bacteria. The five-strain combination had a higher survival rate than the four-strain combination.


Subject(s)
Bacteria, Anaerobic/drug effects , Periapical Periodontitis/microbiology , Periapical Periodontitis/therapy , Root Canal Irrigants/pharmacology , Root Canal Therapy , Animals , Bacteria, Anaerobic/isolation & purification , Dental Pulp Cavity/microbiology , Enterococcus faecalis/drug effects , Enterococcus faecalis/pathogenicity , Female , Fusobacterium nucleatum/drug effects , Fusobacterium nucleatum/pathogenicity , Hydrogen Peroxide/pharmacology , Macaca fascicularis , Peptostreptococcus/drug effects , Peptostreptococcus/pathogenicity , Prevotella/drug effects , Prevotella/pathogenicity , Sodium Hypochlorite/pharmacology , Streptococcus milleri Group/drug effects , Streptococcus milleri Group/pathogenicity
SELECTION OF CITATIONS
SEARCH DETAIL
...