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Biswas S, Rolain JM. Use of MALDI-TOF mass spectrometry for identification of bacteria that are difficult to culture. J Microbiol Methods 2013; 92:14-24. [DOI: 10.1016/j.mimet.2012.10.014] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 10/25/2012] [Accepted: 10/29/2012] [Indexed: 01/22/2023]
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2
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Discerning the role of Bacteroides fragilis in celiac disease pathogenesis. Appl Environ Microbiol 2012; 78:6507-15. [PMID: 22773639 DOI: 10.1128/aem.00563-12] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Celiac disease (CD) is associated with intestinal dysbiosis, which can theoretically lead to dysfunctions in host-microbe interactions and contribute to the disease. In the present study, possible differences in Bacteroides spp. and their pathogenic features between CD patients and controls were investigated. Bacteroides clones (n = 274) were isolated, identified, and screened for the presence of the virulence genes (bft and mpII) coding for metalloproteases. The proteolytic activity of selected Bacteroides fragilis strains was evaluated by zymography and, after gastrointestinal digestion of gliadin, by high-pressure liquid chromatography/electrospray ionization/tandem mass spectrometry. The effects of B. fragilis strains on Caco-2 cell culture permeability and inflammatory response to digested gliadin were determined. B. fragilis was more frequently identified in CD patients than in healthy controls, in contrast to Bacteroides ovatus. B. fragilis clones carrying virulence genes coding for metalloproteases were more abundant in CD patients than in controls. B. fragilis strains, representing the isolated clones and carrying metalloprotease genes, showed gelatinase activity and exerted the strongest adverse effects on the integrity of the Caco-2 cell monolayer. All B. fragilis strains also showed gliadin-hydrolyzing activity, and some of them generated immunogenic peptides that preserved or increased inflammatory cytokine production (tumor necrosis factor alpha) and showed increased ability to permeate through Caco-2 cell cultures. These findings suggest that increased abundance of B. fragilis strains with metalloprotease activities could play a role in CD pathogenesis, although further in vivo studies are required to support this hypothesis.
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Bradley G, Carter J, Gaudie D, King C. Distribution of the human faecal bacterium Bacteroides fragilis, its bacteriophages and their relationship to current sewage pollution indicators in bathing water. J Appl Microbiol 2010; 85 Suppl 1:90S-100S. [DOI: 10.1111/j.1365-2672.1998.tb05287.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Eribe ERK, Olsen I. SDS-PAGE of Whole-Cell Proteins and Random Amplified Polymorphic DNA (RAPD) Analyses of Leptotrichia Isolates. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.1080/08910600310002073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
| | - Ingar Olsen
- Institute of Oral Biology Dental Faculty, University of Oslo Oslo
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Nagy E, Maier T, Urban E, Terhes G, Kostrzewa M. Species identification of clinical isolates of Bacteroides by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry. Clin Microbiol Infect 2009; 15:796-802. [PMID: 19438622 DOI: 10.1111/j.1469-0691.2009.02788.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bacteroides fragilis and related species are important human pathogens involved in mixed infections of different origins. The B. fragilis group isolates are phenotypically very similar, grow more slowly than aerobic bacteria and, accordingly, are frequently misidentifed with classical or automated phenotypical identification methods. Recent taxonomic changes and new species accepted as members of the Bacteroides genus are not included in the different databases of commercially available identification kits. The use of matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was therefore evaluated for the species identification of 277 clinical isolates of the Bacteroides genus. Species identification was carried out with MALDI Bruker Daltonik Biotyper software (Bruker Daltonik GmbH, Bremen, Germany) by comparing the mass spectrum of each strain with the mass spectra of the 3260 reference strains currently available. The results of conventional phenotypical identification of the isolates were used as a reference. 16S rRNA gene sequencing was performed for a selection of the strains that gave discrepant results and for all those inconclusively identified by MALDI-TOF MS; 270 isolates (97.5%) were unequivocally identified [log(score) >/=2.0] by comparison with the reference strains present in the MALDI Biotyper database. Of the 23 isolates for which the MALDI-TOF MS species identification differed from the conventional phenotypical identification, 11 were sequenced. The sequencing data confirmed the MALDI-TOF MS result in ten cases and, for the remaining isolate, the sequencing data did not lead to the determination of the species, but only to that of the genus (Bacteroides sp.). The discriminating power and identification accuracy of MALDI-TOF MS proved to be superior to that of biochemical testing for Bacteroides thetaiotaomicron, Bacteroides ovatus and Bacteroides uniformis.
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Affiliation(s)
- E Nagy
- Institute of Clinical Microbiology, University of Szeged, H-6701 Szeged, Hungary.
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Fang H, Hedberg M, Edlund C, Jarstrand C, Fodor E, Nord CE. Characterization of beta-lactam-resistant Bacteroides fragilis isolates by use of PCR fingerprinting. Anaerobe 2007; 5:11-8. [PMID: 16887657 DOI: 10.1006/anae.1999.0183] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/1998] [Accepted: 02/08/1999] [Indexed: 11/22/2022]
Abstract
PCR fingerprinting was used for characterization of 35 beta-lactam-resistant Bacteroides fragilis strains isolated in Sweden and Hungary. Ten B. fragilis strains showed unique PCR fingerprints by use of the M13 core primer. Their main product was a DNA fragment with a length of 2000-bp which was absent in the other 25 strains and the reference strain B. fragilis ATCC 25285. The 2000-bp fragment from four imipenem-resistant strains gave rise to positive reactions in a specific PCR for detection of ccrA. Printed by the T3B primer, five B. fragilis strains, including the imipenem-resistant strains showed unique PCR fingerprints. The investigated imipenem-resistant strains produced carbapenem-hydrolysing metallo-beta-lactamases. The study indicates that the unique PCR fingerprinting profiles shown in highly beta-lactam resistant B. fragilis strains are correlated to antimicrobial resistance. The PCR fingerprinting technique is a useful tool for differentiation of Bacteroides fragilis strains with high-level beta-lactam resistance.
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Affiliation(s)
- H Fang
- Department of Immunology, Microbiology, Pathology and Infectious Diseases, Karolinska Institute, Huddinge University Hospital, S-141 86, Huddinge, Sweden
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Claros MC, Claros ZC, Hecht DW, Citron DM, Goldstein EJC, Silva J, Tang-Feldman Y, Rodloff AC. Characterization of the Bacteroides fragilis pathogenicity island in human blood culture isolates. Anaerobe 2005; 12:17-22. [PMID: 16701608 DOI: 10.1016/j.anaerobe.2005.06.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2004] [Revised: 06/15/2005] [Accepted: 06/15/2005] [Indexed: 11/20/2022]
Abstract
Bacteroides fragilis is an important anaerobic pathogen accounting for up to 10% of bacteremias in adult patients. Enterotoxin producing B. fragilis (ETBF) strains have been identified as enteric pathogens of children and adults. In order to further characterize the B. fragilis pathogenicity island (BfPAI) and using PCR assays for bft- and mpII-metalloprotease genes, we determined the frequency of B. fragilis strains with pattern I (containing the BfPAI and its flanking region), pattern II (lacking both the BfPAI and the flanking region), and pattern III (lacking the BfPAI but containing the flanking region) in 63 blood culture isolates. The results were compared to 197 B. fragilis isolates from different clinical sources. We found 19% of blood culture isolates were pattern I (ETBF), 43% were pattern II (NTBF) and 38% were pattern III (NTBF). Comparatively, B. fragilis isolates from other clinical sources were 10% pattern I, 47% pattern II and 43% pattern III. This suggests that the pathogenicity island and the flanking elements may be general virulence factors of B. fragilis.
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Affiliation(s)
- M C Claros
- Institute of Medical Microbiology and Infectious Epidemiology, University of Leipzig, Germany.
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Sóki J, Edwards R, Urbán E, Fodor E, Beer Z, Nagy E. Screening of isolates from faeces for carbapenem-resistant Bacteroides strains; existence of strains with novel types of resistance mechanisms. Int J Antimicrob Agents 2004; 24:450-4. [PMID: 15519476 DOI: 10.1016/j.ijantimicag.2004.06.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2004] [Accepted: 06/30/2004] [Indexed: 11/26/2022]
Abstract
Isolates from faecal samples (n = 224) from the UK and Hungary were screened for carbapenem-resistant Bacteroides strains and were consecutively investigated for the resistance mechanisms through detection of cfiA genes, the presence or lack of insertion sequence insertions in their upstream regions and the production of carbapenemase activities. In this way, a significant number of strains (n = 7, 3.1%) were recovered. They included 2 Bacteroides fragilis strains (one in each country) which harboured cfiA genes, but which were not activated by insertion sequence elements; this is reminiscent of some novel clinical B. fragilis strains. The cfiA-negative strains exhibited lower levels of carbapenem resistance and varying levels of carbapenemase activity, suggesting that other resistance mechanisms may also exist.
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Affiliation(s)
- József Sóki
- Department of Clinical Microbiology, Faculty of Medicine, University of Szeged, Szeged, H-6725 Szeged, Somogyi Béla tér 1, Hungary.
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Claros MC, Claros ZC, Tang YJ, Cohen SH, Silva J, Goldstein EJ, Rodloff AC. Occurrence of Bacteroides fragilis enterotoxin gene-carrying strains in Germany and the United States. J Clin Microbiol 2000; 38:1996-7. [PMID: 10790139 PMCID: PMC86649 DOI: 10.1128/jcm.38.5.1996-1997.2000] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ninety-three Bacteroides fragilis isolates from different geographic locations were analyzed for the presence of an enterotoxin-encoding gene. It was shown that blood culture isolates were more likely to carry this gene than strains from other sources. All enterotoxin-positive strains belonged to the PCR fingerprint group I.
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Affiliation(s)
- M C Claros
- Institute of Medical Microbiology and Infectious Epidemiology, University of Leipzig, Leipzig, Germany.
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Characteristics of Fusobacterium ulcerans, a New and Unusual Species Compared with Fusobacterium varium and Fusobacterium mortiferum. Anaerobe 1999. [DOI: 10.1006/anae.1999.0201] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Domingues RM, Avelar KE, Souza WG, Moraes SR, Antunes EN, Oliveira IA, Ferreira MC. Whole-cell and periplasmic protein banding patterns of environmental and human Bacteroides fragilis strains. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1997; 286:305-15. [PMID: 9361378 DOI: 10.1016/s0934-8840(97)80088-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In order to investigate the relationship among virulent and avirulent Bacteroides fragilis strains, SDS-PAGE of whole-cell proteins (WP) and periplasmic proteins (PP) were used to establish a protein profile of strains isolated from human infections, fecal flora and environmental water. Despite different sources of the strains, no significant differences were observed as determined by the WP SDS-PAGE analysis. In contrast, the proteins obtained from the bacterial periplasm showed differences in the electrophoretic protein profile. Two distinct PP profile patterns were obtained. Pattern A included 6 out of the 8 virulent strains and pattern B, 6 out of 8 avirulent strains. Interestingly, an environmental strain that was capable of inducing abscesses in mice, had a PP profile highly similar to that of the virulent strains from human infections. These data indicate that PP from B. fragilis may be useful to characterize differences among virulent and avirulent strains. Moreover, strains isolated from environmental water may also be a source of exogenous infections by B. fragilis.
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Affiliation(s)
- R M Domingues
- Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Brasil
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Alexander CJ, Citron DM, Hunt Gerardo S, Claros MC, Talan D, Goldstein EJ. Characterization of saccharolytic Bacteroides and Prevotella isolates from infected dog and cat bite wounds in humans. J Clin Microbiol 1997; 35:406-11. [PMID: 9003606 PMCID: PMC229590 DOI: 10.1128/jcm.35.2.406-411.1997] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Saccharolytic, nonpigmented, anaerobic gram-negative rods isolated from infected dog and cat bite wounds in humans have been poorly characterized, and most are not included in the databases of kits used for anaerobic identification; thus, they are problematic for clinical laboratories to identify. Fifty strains isolated from such wounds were characterized with commercial kits for preformed-enzyme detection, carbohydrate fermentation, and other biochemical tests. PCR fingerprinting was performed on these strains to further characterize subgroups within these species. Bacteroides tectum is a frequent isolate in bite wounds and resembles Prevotella bivia in colony morphology and saccharolytic activity, except that it grows in 20% bile and hydrolyzes esculin. Profile numbers generated by various kits associate B. tectum with P. bivia, Prevotella oralis group, or Prevotella melaninogenica. PCR fingerprinting identified at least four subgroups and confirmed the heterogeneous nature of this species. Prevotella heparinolytica was also frequently isolated from these bite wounds. It produces indole and generates a profile number in preformed-enzyme kits that is usually associated with Bacteroides uniformis. However, it is bile sensitive and quite distinct from the Bacteroides fragilis group of anaerobes. The PCR fingerprint profiles generated by strains of P. heparinolytica were very similar to that of the type strain and to each other. Prevotella zoogleoformans, occasionally isolated from dog and cat bite wounds in humans, resembles P. heparinolytica except for a negative indole test. Clinical laboratories should be aware of the characteristics of these animal species when identifying isolates from animal bite wounds in humans.
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Affiliation(s)
- C J Alexander
- R. M. Alden Research Laboratory, Santa Monica/UCLA Medical Center, California 90404, USA
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