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Dadgar-Zankbar L, Shariati A, Bostanghadiri N, Elahi Z, Mirkalantari S, Razavi S, Kamali F, Darban-Sarokhalil D. Evaluation of enterotoxigenic Bacteroides fragilis correlation with the expression of cellular signaling pathway genes in Iranian patients with colorectal cancer. Infect Agent Cancer 2023; 18:48. [PMID: 37644520 PMCID: PMC10463534 DOI: 10.1186/s13027-023-00523-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/02/2023] [Indexed: 08/31/2023] Open
Abstract
BACKGROUND Colorectal cancer (CRC) is one of the most common cancers all over the world, and dysbiosis in the gut microbiota may play a role in colorectal carcinogenesis. Bacteroides fragilis can lead to tumorigenesis by changing signaling pathways, including the WNT/β-catenin pathway. Therefore, in the present study, we investigated the correlation between the enterotoxigenic B. fragilis amount and the expression of signaling pathway genes involved in CRC. MATERIALS AND METHODS B. fragilis was determined in 30 tumors and adjacent healthy tissues by the qPCR method. Next, the relationship between enterotoxigenic B. fragilis and the expression of signaling pathway genes, including CCND1, TP53, BCL2, BAX, WNT, TCF, AXIN, APC, and CTNNB1 was investigated. Additionally, possible correlations between clinicopathological features of the tumor samples and the abundance of B. fragilis were analyzed. RESULTS The results showed that B. fragilis was detected in 100% of tumor samples and 86% of healthy tissues. Additionally, enterotoxigenic B. fragilis colonized 47% of all samples, and bft-1 toxin was the most frequently found isotype among the samples. The analysis showed that the high level of B. fragilis has a significant relationship with the high expression of AXIN, CTNNB1, and BCL2 genes. On the other hand, our results did not show any possible correlation between this bacterium and the clinicopathological features of the tumor sample. CONCLUSION B. fragilis had a higher abundance in the tumor samples than in healthy tissues, and this bacterium may lead to CRC by making changes in cellular signaling pathways and genes. Therefore, to better understand the physiological effects of B. fragilis on the inflammatory response and CRC, future research should focus on dissecting the molecular mechanisms by which this bacterium regulates cellular signaling pathways.
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Affiliation(s)
- Leila Dadgar-Zankbar
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Aref Shariati
- Molecular and Medicine Research Center, Khomein University of Medical Sciences, Khomein, Iran
- Student Research Committee, Khomein University of Medical Sciences, Khomein, Iran
| | - Narjess Bostanghadiri
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Zahra Elahi
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shiva Mirkalantari
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shabnam Razavi
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Kamali
- Iran National Tumor Bank, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran
| | - Davood Darban-Sarokhalil
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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Li P, Shuai P, Shen S, Zheng H, Sun P, Zhang R, Lan S, Lan Z, Jayawardana T, Yang Y, Zhao J, Liu Y, Chen X, El-Omar EM, Wan Z. Perturbations in gut microbiota composition in patients with polycystic ovary syndrome: a systematic review and meta-analysis. BMC Med 2023; 21:302. [PMID: 37559119 PMCID: PMC10413517 DOI: 10.1186/s12916-023-02975-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 07/10/2023] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND The results of human observational studies on the correlation between gut microbiota perturbations and polycystic ovary syndrome (PCOS) have been contradictory. This study aimed to perform the first systematic review and meta-analysis to evaluate the specificity of the gut microbiota in PCOS patients compared to healthy women. METHODS Literature through May 22, 2023, was searched on PubMed, Web of Science, Medline, Embase, Cochrane Library, and Wiley Online Library databases. Unreported data in diversity indices were filled by downloading and processing raw sequencing data. Systematic review inclusion: original studies were eligible if they applied an observational case-control design, performed gut microbiota analysis and reported diversity or abundance measures, sampled general pre-menopausal women with PCOS, and are longitudinal studies with baseline comparison between PCOS patients and healthy females. Systematic review exclusion: studies that conducted interventional or longitudinal comparisons in the absence of a control group. Two researchers made abstract, full-text, and data extraction decisions, independently. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the methodologic quality. Hedge's g standardized mean difference (SMD), confidence intervals (CIs), and heterogeneity (I2) for alpha diversity were calculated. Qualitative syntheses of beta-diversity and microbe alterations were performed. RESULTS Twenty-eight studies (n = 1022 patients, n = 928 control) that investigated gut microbiota by collecting stool samples were included, with 26 and 27 studies having provided alpha-diversity and beta-diversity results respectively. A significant decrease in microbial evenness and phylogenetic diversity was observed in PCOS patients when compared with control participants (Shannon index: SMD = - 0.27; 95% CI, - 0.37 to - 0.16; phylogenetic diversity: SMD = - 0.39; 95% CI, -- 0.74 to - 0.03). We also found that reported beta-diversity was inconsistent between studies. Despite heterogeneity in bacterial relative abundance, we observed depletion of Lachnospira and Prevotella and enrichment of Bacteroides, Parabacteroides, Lactobacillus, Fusobacterium, and Escherichia/Shigella in PCOS. Gut dysbiosis in PCOS, which might be characterized by the reduction of short-chain fatty acid (SCFA)-producing and bile-acid-metabolizing bacteria, suggests a shift in balance to favor pro-inflammatory rather than anti-inflammatory bacteria. CONCLUSIONS Gut dysbiosis in PCOS is associated with decreased diversity and alterations in bacteria involved in microbiota-host crosstalk. TRIAL REGISTRATION PROSPERO registration: CRD42021285206, May 22, 2023.
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Affiliation(s)
- Pan Li
- Department of Obstetrics and Gynecology, The First People's Hospital of Foshan, No.81 Lingnan Avenue North, Chancheng District, Foshan, Guangdong Province, China
- UNSW Microbiome Research Centre, St George and Sutherland Clinical Campuses, UNSW Sydney, Clinical Sciences (WR Pitney) Building, Short St, Kogarah, NSW, 2217, Australia
| | - Ping Shuai
- Department of Health Management & Institute of Health Management, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32 West Second Section, First Ring Rd., Qing yang Dist, Chengdu, China
| | - Sj Shen
- UNSW Microbiome Research Centre, St George and Sutherland Clinical Campuses, UNSW Sydney, Clinical Sciences (WR Pitney) Building, Short St, Kogarah, NSW, 2217, Australia
| | - Huimin Zheng
- Department of Obstetrics and Gynecology, The First People's Hospital of Foshan, No.81 Lingnan Avenue North, Chancheng District, Foshan, Guangdong Province, China
| | - Ping Sun
- Department of Health Management & Institute of Health Management, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32 West Second Section, First Ring Rd., Qing yang Dist, Chengdu, China
| | - Renfang Zhang
- Department of Obstetrics and Gynecology, The First People's Hospital of Foshan, No.81 Lingnan Avenue North, Chancheng District, Foshan, Guangdong Province, China
| | - Shanwei Lan
- The Second Clinical Medical College, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Zixin Lan
- The Second Clinical Medical College, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Thisun Jayawardana
- UNSW Microbiome Research Centre, St George and Sutherland Clinical Campuses, UNSW Sydney, Clinical Sciences (WR Pitney) Building, Short St, Kogarah, NSW, 2217, Australia
| | - Yumei Yang
- Department of Health Management & Institute of Health Management, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Jianhui Zhao
- Department of Big Data in Health Science School of Public Health, and Epidemiology and Biostatistics, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuping Liu
- Department of Health Management & Institute of Health Management, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32 West Second Section, First Ring Rd., Qing yang Dist, Chengdu, China
| | - Xia Chen
- Department of Obstetrics and Gynecology, The First People's Hospital of Foshan, No.81 Lingnan Avenue North, Chancheng District, Foshan, Guangdong Province, China.
| | - Emad M El-Omar
- UNSW Microbiome Research Centre, St George and Sutherland Clinical Campuses, UNSW Sydney, Clinical Sciences (WR Pitney) Building, Short St, Kogarah, NSW, 2217, Australia.
| | - Zhengwei Wan
- Department of Health Management & Institute of Health Management, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, No. 32 West Second Section, First Ring Rd., Qing yang Dist, Chengdu, China.
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Spigaglia P, Barbanti F, Germinario EAP, Criscuolo EM, Bruno G, Sanchez-Mete L, Porowska B, Stigliano V, Accarpio F, Oddi A, Zingale I, Rossi S, De Angelis R, Fabbri A. Comparison of microbiological profile of enterotoxigenic Bacteroides fragilis (ETBF) isolates from subjects with colorectal cancer (CRC) or intestinal pre-cancerous lesions versus healthy individuals and evaluation of environmental factors involved in intestinal dysbiosis. Anaerobe 2023; 82:102757. [PMID: 37380012 DOI: 10.1016/j.anaerobe.2023.102757] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/14/2023] [Accepted: 06/20/2023] [Indexed: 06/30/2023]
Abstract
OBJECTIVE The aim of this study was to analyze enterotoxigenic Bacteroides fragilis (ETBF) isolates from colorectal biopsies of subjects with a histological analysis positive for colorectal cancer (CRC), pre-cancerous lesions (pre-CRC) or with a healthy intestinal tissue and to evaluate the environmental factors that may not only concur to CRC development but may also affect gut microbiota composition. METHODS ETBF isolates were typed using the ERIC-PCR method, while PCR assays were performed to investigate the bft alleles, the B. fragilis pathogenicity island (BFPAI) region and the cepA, cfiA and cfxA genes. Susceptibility to antibiotics was tested using the agar dilution method. Environmental factors that could play a role in promoting intestinal dysbiosis were evaluated throughout a questionnaire administered to the subjects enrolled. RESULTS Six different ERIC-PCR types were identified. The type denominated C in this study was the most prevalent, in particular among the biopsies of subjects with pre-CRC, while an isolate belonging to a different type, denominated F, was detected in a biopsy from a subject with CRC. All the ETBF isolates from pre-CRC or CRC subjects had a B. fragilis pathogenicity island (BFPAI) region pattern I, while those from healthy individuals showed also different patterns. Furthermore, 71% of isolates from subjects with pre-CRC or CRC were resistant to two or more classes of antibiotics vs 43% of isolates from healthy individuals. The B. fragilis toxin BFT1 was the most frequently detected in this study, confirming the constant circulation of this isoform strains in Italy. Interestingly, BFT1 was found in 86% of the ETBF isolates from patients with CRC or pre-CRC, while the BFT2 was prevalent among the ETBF isolates from healthy subjects. No substantial differences based on sex, age, tobacco and alcohol consumption were observed between healthy and non-healthy individuals included in this study, while most of the subjects with CRC or pre-CRC lesions were subjected to pharmacological therapy (71%) and showed a body mass index (BMI) that falls within the overweight range (86%). CONCLUSIONS Our data suggest that some types of ETBF seem to better adapt and colonize the human gut and that the selective pressure exerted by factors related to lifestyle, such as pharmacological therapy and weight, could facilitate their persistence in the gut and their possible involvement in CRC development.
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Affiliation(s)
- Patrizia Spigaglia
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161, Rome, Italy.
| | - Fabrizio Barbanti
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161, Rome, Italy.
| | - Elena Angela Pia Germinario
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161, Rome, Italy.
| | | | - Giovanni Bruno
- Department of Translational and Precision Medicine, Gastroenterology Unit, Policlinic Umberto I, University of Rome 'Sapienza', 00161, Rome, Italy.
| | - Lupe Sanchez-Mete
- Gastroenterology and Digestive Endoscopy IRCCS Regina Elena National Cancer Institute, 00144, Rome, Italy.
| | - Barbara Porowska
- Digestive Endoscopy UOC CSC03 of the Department of General Surgery, Surgical Specialities "Paride Stefanini", Policlinic Umberto I, University of Rome 'Sapienza', 00161, Rome, Italy.
| | - Vittoria Stigliano
- Gastroenterology and Digestive Endoscopy IRCCS Regina Elena National Cancer Institute, 00144, Rome, Italy.
| | - Fabio Accarpio
- Digestive Endoscopy UOC CSC03 of the Department of General Surgery, Surgical Specialities "Paride Stefanini", Policlinic Umberto I, University of Rome 'Sapienza', 00161, Rome, Italy.
| | - Andrea Oddi
- Hepatopancreatobiliary Surgery, IRCCS Regina Elena National Cancer Institute, 00114, Rome, Italy.
| | - Ilaria Zingale
- Digestive Endoscopy UOC CSC03 of the Department of General Surgery, Surgical Specialities "Paride Stefanini", Policlinic Umberto I, University of Rome 'Sapienza', 00161, Rome, Italy.
| | - Silvia Rossi
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161, Rome, Italy.
| | - Roberta De Angelis
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161, Rome, Italy.
| | - Alessia Fabbri
- Department of Cardiovascular, Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanità, 00161, Rome, Italy.
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Guo Y, Ouyang Z, He W, Zhang J, Qin Q, Jiao M, Muyldermans S, Zheng F, Wen Y. Screening and epitope characterization of diagnostic nanobody against total and activated Bacteroides fragilis toxin. Front Immunol 2023; 14:1065274. [PMID: 36845160 PMCID: PMC9950733 DOI: 10.3389/fimmu.2023.1065274] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 01/19/2023] [Indexed: 02/12/2023] Open
Abstract
Enterotoxigenic Bacteroides fragilis (ETBF) can rapidly secrete an enterotoxin termed B. fragilis toxin (BFT), which is thought to be the only recognized virulence factor in ETBF. ETBF can cause acute diarrhea, inflammatory bowel disease (IBD), colorectal cancer, and breast cancer. BFT is divided into three subtypes, BFT1, BFT2, and BFT3. BFT1 is the most widely distributed in human B. fragilis isolates. BFT can be used as a biomarker for predicting the inflammation-cancer transformation of intestine and breast. Nanobodies have the advantages of small structure, complete antigen recognition capacity, rapid selection via phage display technology, and can be massively produced in microbial expression systems. Nanobodies have become a powerful tool for medical diagnosis and treatment. This study focuses on screening and structural characterization of nanobodies targeting full length and active BFT. By constructing prokaryotic expression systems to obtain recombinant BFT1 protein, high purity BFT1 protein was used to immunize alpacas. Phage display technology was used to construct a phage display library. The positive clones were selected by bio-panning, and the isothermal titration calorimetry was used to select high-affinity nanobodies. Then the three-dimensional structures of BFT1:Nb2.82 and BFT1:Nb3.27 were solved by crystal X-ray diffraction. We got two kinds of nanobodies, Nb2.82 targeting the BFT1 prodomain and Nb3.27 recognizing the BFT1 catalytic domain. This study provides a new strategy for the early diagnosis of ETBF and the possibility for BFT as a biomarker for diagnosing diseases.
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Affiliation(s)
- Yucheng Guo
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Zhenlin Ouyang
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Wenbo He
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Jiaxin Zhang
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Qian Qin
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Min Jiao
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Serge Muyldermans
- Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Fang Zheng
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China,*Correspondence: Yurong Wen, ; Fang Zheng,
| | - Yurong Wen
- Center for Microbiome Research of Med-X Institute, The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China,*Correspondence: Yurong Wen, ; Fang Zheng,
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Jasemi S, Emaneini M, Ahmadinejad Z, Fazeli MS, Sechi LA, Sadeghpour Heravi F, Feizabadi MM. Antibiotic resistance pattern of Bacteroides fragilis isolated from clinical and colorectal specimens. Ann Clin Microbiol Antimicrob 2021; 20:27. [PMID: 33892721 PMCID: PMC8066845 DOI: 10.1186/s12941-021-00435-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/16/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Bacteroides fragilis is a part of the normal gastrointestinal flora, but it is also the most common anaerobic bacteria causing the infection. It is highly resistant to antibiotics and contains abundant antibiotic resistance mechanisms. METHODS The antibiotic resistance pattern of 78 isolates of B. fragilis (22 strains from clinical samples and 56 strains from the colorectal tissue) was investigated using agar dilution method. The gene encoding Bacteroides fargilis toxin bft, and antibiotic resistance genes were targeted by PCR assay. RESULTS The highest rate of resistance was observed for penicillin G (100%) followed by tetracycline (74.4%), clindamycin (41%) and cefoxitin (38.5%). Only a single isolate showed resistance to imipenem which contained cfiA and IS1186 genes. All isolates were susceptible to metronidazole. Accordingly, tetQ (87.2%), cepA (73.1%) and ermF (64.1%) were the most abundant antibiotic-resistant genes identified in this study. MIC values for penicillin, cefoxitin and clindamycin were significantly different among isolates with the cepA, cfxA and ermF in compare with those lacking such genes. In addition, 22.7 and 17.8% of clinical and GIT isolates had the bft gene, respectively. CONCLUSIONS The finding of this study shows that metronidazole is highly in vitro active agent against all of B. fragilis isolates and remain the first-line antimicrobial for empirical therapy.
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Affiliation(s)
- Seyedesomaye Jasemi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Poursina Street, Engelab-e-Eslami Avenue, Tehran, Iran
| | - Mohammad Emaneini
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Poursina Street, Engelab-e-Eslami Avenue, Tehran, Iran
| | - Zahra Ahmadinejad
- Department of Infectious Diseases, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sadegh Fazeli
- Department of Surgery, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Leonardo A Sechi
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Fatemah Sadeghpour Heravi
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Mohammad Mehdi Feizabadi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Poursina Street, Engelab-e-Eslami Avenue, Tehran, Iran. .,Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
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Abstract
The functional diversity of the mammalian intestinal microbiome far exceeds that of the host organism, and microbial genes contribute substantially to the well-being of the host. However, beneficial gut organisms can also be pathogenic when present in the gut or other locations in the body. Among dominant beneficial bacteria are several species of Bacteroides, which metabolize polysaccharides and oligosaccharides, providing nutrition and vitamins to the host and other intestinal microbial residents. These topics and the specific organismal and molecular interactions that are known to be responsible for the beneficial and detrimental effects of Bacteroides species in humans comprise the focus of this review. The complexity of these interactions will be revealed.
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Affiliation(s)
- Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, USA
- Department of Microbiology and Molecular Genetics, Faculty of Life Sciences, University of Okara,Okara, PunjabPakistan
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, USA
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Yekani M, Baghi HB, Naghili B, Vahed SZ, Sóki J, Memar MY. To resist and persist: Important factors in the pathogenesis of Bacteroides fragilis. Microb Pathog 2020; 149:104506. [PMID: 32950639 DOI: 10.1016/j.micpath.2020.104506] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/15/2020] [Accepted: 09/15/2020] [Indexed: 02/07/2023]
Abstract
Bacteroides fragilis is a most frequent anaerobic pathogen isolated from human infections, particularly found in the abdominal cavity. Different factors contribute to the pathogenesis and persistence of B. fragilis at infection sites. The knowledge of the virulence factors can provide applicable information for finding alternative options for the antibiotic therapy and treatment of B. fragilis caused infections. Herein, a comprehensive review of the important B. fragilis virulence factors was prepared. In addition to B. fragilis toxin (BFT) and its potential role in the diarrhea and cancer development, some other important virulence factors and characteristics of B. fragilis are described including capsular polysaccharides, iron acquisition, resistance to antimicrobial agents, and survival during the prolonged oxidative stress, quorum sensing, and secretion systems.
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Affiliation(s)
- Mina Yekani
- Department of Microbiology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran; Student Research Committee,Kashan University of Medical Sciences, Kashan, Iran
| | - Hossein Bannazadeh Baghi
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behrooz Naghili
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - József Sóki
- Institute of Clinical Microbiology, Faculty of Medicine, University of Szeged, Szeged, Hungary.
| | - Mohammad Yousef Memar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Microbiology Department, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
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8
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Jasemi S, Emaneini M, Fazeli MS, Ahmadinejad Z, Nomanpour B, Sadeghpour Heravi F, Sechi LA, Feizabadi MM. Toxigenic and non-toxigenic patterns I, II and III and biofilm-forming ability in Bacteroides fragilis strains isolated from patients diagnosed with colorectal cancer. Gut Pathog 2020; 12:28. [PMID: 32518594 PMCID: PMC7273666 DOI: 10.1186/s13099-020-00366-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 05/30/2020] [Indexed: 12/12/2022] Open
Abstract
Background Enterotoxigenic Bacteroides fragilis (ETBF) associated with the initiation and progression of colorectal cancer (CRC) has been alarmingly reported all over the world. In this study, simultaneous investigation of toxigenic and non-toxigenic patterns I, II and III and biofilm formation ability of Bacteroides fragilis isolated from patients with colorectal cancer was performed. Methods Thirty-one patients diagnosed with CRC and thirty-one control subjects were recruited in this study. Specimens were cultured on BBE and BBA culture media. Classical phenotypic identification tests and PCR was performed to verify Bacteroides fragilis presence. Also, biofilm-forming ability and expression of bft gene were assessed under biofilm and planktonic forms. Results A total of 68 B.fragilis was isolated from all colorectal tissue, of which 13 isolates (19.1%) (11 isolates from CRC and 2 from normal tissue) were positive for bft gene. The abundance patterns of I, II and III were as follow in descending order; pattern I > pattern III > pattern II in CRC subjects and pattern II > pattern III > pattern I in normal tissues. Also, pattern I showed higher biofilm formation ability compared to other patterns. Toxin expression was significantly reduced in biofilm form comparing with planktonic form. Conclusions Based on our findings, there was a difference between the abundance of patterns I, II, and III and biofilm formation in isolates obtained from CRC and normal tissues. Biofilm formation ability and toxin encoding gene (bft) are two main virulence factors in B. fragilis pathogenicity which require more investigation to treat B. fragilis infections effectively.
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Affiliation(s)
- Seyedesomaye Jasemi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Emaneini
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sadegh Fazeli
- Department of Surgery, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Ahmadinejad
- Department of Infectious Diseases, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Bizhan Nomanpour
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Fatemah Sadeghpour Heravi
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Leonardo A Sechi
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Mohammad Mehdi Feizabadi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Department of Biomedical Sciences, University of Sassari, Sassari, Italy
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Valguarnera E, Wardenburg JB. Good Gone Bad: One Toxin Away From Disease for Bacteroides fragilis. J Mol Biol 2019; 432:765-785. [PMID: 31857085 DOI: 10.1016/j.jmb.2019.12.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 11/27/2019] [Accepted: 12/05/2019] [Indexed: 02/06/2023]
Abstract
The human gut is colonized by hundreds of trillions of microorganisms whose acquisition begins during early infancy. Species from the Bacteroides genus are ubiquitous commensals, comprising about thirty percent of the human gut microbiota. Bacteroides fragilis is one of the least abundant Bacteroides species, yet is the most common anaerobe isolated from extraintestinal infections in humans. A subset of B. fragilis strains carry a genetic element that encodes a metalloprotease enterotoxin named Bacteroides fragilis toxin, or BFT. Toxin-bearing strains, or Enterotoxigenic B. fragilis (ETBF) cause acute and chronic intestinal disease in children and adults. Despite this association with disease, around twenty percent of the human population appear to be asymptomatic carriers of ETBF. BFT damages the colonic epithelial barrier by inducing cleavage of the zonula adherens protein E-cadherin and initiating a cell signaling response characterized by inflammation and c-Myc-dependent pro-oncogenic hyperproliferation. As a consequence, mice harboring genetic mutations that predispose to colonic inflammation or tumor formation are uniquely susceptible to toxin-mediated injury. The recent observation of ETBF-bearing biofilms in colon biopsies from humans with colon cancer susceptibility loci strongly suggests that ETBF is a driver of colorectal cancer. This article will address ETBF biology from a host-pathobiont perspective, including clinical data, analysis of molecular mechanisms of disease, and the complex ecological context of the human gut.
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Affiliation(s)
- Ezequiel Valguarnera
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Ave. Box 8208, St. Louis, MO 63110
| | - Juliane Bubeck Wardenburg
- Department of Pediatrics, Washington University School of Medicine, 660 S. Euclid Ave. Box 8208, St. Louis, MO 63110.
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Haghi F, Goli E, Mirzaei B, Zeighami H. The association between fecal enterotoxigenic B. fragilis with colorectal cancer. BMC Cancer 2019; 19:879. [PMID: 31488085 PMCID: PMC6727388 DOI: 10.1186/s12885-019-6115-1] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/30/2019] [Indexed: 02/06/2023] Open
Abstract
Background Enterotoxigenic Bacteroides fragilis (ETBF) is an enterotoxin-producing bacterium that possibily has a role in the occurrence and progression of colorectal cancer (CRC) by modulating the mucosal immune response and inducing epithelial cell changes. The aim of this study was to investigate the frequency of ETBF in stool samples of CRC patients and healthy volunteers. Methods A total of 60 stool samples from confirmed CRC patients and 60 stool samples from healthy volunteers with no personal or familial history or diagnosis of colorectal disease were collected. Stool samples were screened for direct detection of B. fragilis using PCR targeting the marker genes of neu and bft. Enterotoxin isotypes bft-1, bft-2 and bft-3 were also detected in B. fragilis positive samples. Results The frequency of B. fragilis among CRC and control cases was 58.3 and 26.6%, respectively (P < 0.05). The rate of bft gene in CRC cases was significantly higher than in controls (P < 0.05). Also, the presence of bft gene in CRC patients stage III was significantly higher than stages I and II (P < 0.05). Enterotoxin isotype bft-2 was detected with higher frequency among CRC patients than healthy control (P < 0.05). Conclusion Our results show the association between fecal ETBF and CRC, and we suggest that detection of ETBF may be a potential marker for colorectal cancer diagnosis. However, additional investigations on tumor and paired normal tissue samples are required to substantiate this possible correlation.
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Affiliation(s)
- Fakhri Haghi
- Department of Microbiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Elshan Goli
- Department of Microbiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Bahman Mirzaei
- Department of Microbiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Habib Zeighami
- Department of Microbiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
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Kouhsari E, Mohammadzadeh N, Kashanizadeh MG, Saghafi MM, Hallajzadeh M, Fattahi A, Ahmadi A, Niknejad F, Ghafouri Z, Asadi A, Boujary Nasrabadi MR. Antimicrobial resistance, prevalence of resistance genes, and molecular characterization in intestinalBacteroides fragilisgroup isolates. APMIS 2019; 127:454-461. [DOI: 10.1111/apm.12943] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/21/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Ebrahim Kouhsari
- Department of Microbiology School of Medicine Iran University of Medical Sciences Tehran Iran
- Laboratory Sciences Research Center Golestan University of Medical Sciences Gorgan Iran
| | - Nima Mohammadzadeh
- Department of Microbiology School of Medicine Iran University of Medical Sciences Tehran Iran
| | | | - Mohammad Mehdi Saghafi
- Department of Clinical Pharmacology Firouz Abadi Hospital Iran University of Medical Sciences Tehran Iran
| | - Masoumeh Hallajzadeh
- Department of Microbiology School of Medicine Iran University of Medical Sciences Tehran Iran
| | - Azam Fattahi
- Center for Research and Training in Skin Disease and Leprosy Tehran University of Medical Sciences Tehran Iran
| | - Alireza Ahmadi
- Laboratory Sciences Research Center Golestan University of Medical Sciences Gorgan Iran
| | - Farhad Niknejad
- Laboratory Sciences Research Center Golestan University of Medical Sciences Gorgan Iran
| | - Zahra Ghafouri
- Department of Biochemistry, Biophysics and Genetics Faculty of Medicine Mazandaran University of Medical Sciences Sari Iran
| | - Arezoo Asadi
- Department of Microbiology School of Medicine Iran University of Medical Sciences Tehran Iran
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Sárvári KP, Sóki J, Iván M, Miszti C, Latkóczy K, Melegh SZ, Urbán E. Detection of enterotoxin and protease genes among Hungarian clinical Bacteroides fragilis isolates. Anaerobe 2017; 48:98-102. [DOI: 10.1016/j.anaerobe.2017.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/19/2017] [Accepted: 07/23/2017] [Indexed: 11/29/2022]
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Kim M, Kim H, Ji SE, Rim JH, Gwon SY, Kim WH, Rhee KJ, Lee K. Characterization of bftGenes among Enterotoxigenic Bacteroides fragilisIsolates from Extraintestinal Specimens at a University Hospital in Korea. KOREAN JOURNAL OF CLINICAL LABORATORY SCIENCE 2016. [DOI: 10.15324/kjcls.2016.48.2.82] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Myungsook Kim
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Hyunsoo Kim
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Seung Eun Ji
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
| | - John Hoon Rim
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Sun Yeong Gwon
- Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University at Wonju, Wonju 26493, Korea
| | - Wan Hee Kim
- KOTITI Testing and Research Institute, Seongnam 13202, Korea
| | - Ki-Jong Rhee
- Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University at Wonju, Wonju 26493, Korea
| | - Kyungwon Lee
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Korea
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Ramamurthy D, Pazhani GP, Sarkar A, Nandy RK, Rajendran K, Sur D, Manna B, Ramamurthy T. Case-control study on the role of enterotoxigenic Bacteroides fragilis as a cause of diarrhea among children in Kolkata, India. PLoS One 2013; 8:e60622. [PMID: 23577134 PMCID: PMC3618056 DOI: 10.1371/journal.pone.0060622] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 02/28/2013] [Indexed: 02/02/2023] Open
Abstract
A total of 874 fecal specimens (446 diarrheal cases and 428 controls) from diarrheal children admitted in the Infectious Diseases Hospital, Kolkata and age and sex matched asymptomatic subjects from an urban community were assessed for the prevalence of enterotoxigenic Bacteroides fragilis (ETBF). Isolates of B. fragilis were tested for the presence of enterotoxin gene (bft) by PCR. The detection rate of ETBF was 7.2% (63 of 874 specimens) that prevailed equally in diarrheal cases and controls (7.2% each; 32 of 446 cases and 31 of 428 controls). Male children up to one year age group was significantly (p<0.05) associated with ETBF infection as compared to children > 2 years of age in cases and controls. In 25 ETBF isolates, the bft gene was genotyped using PCR-RFLP and only two alleles were identified with prevalence rate of 40% and 60% for bft-1 and bft-3, respectively. All the ETBF isolates were susceptible for chloramphenicol and imipenem but resistant to clindamycin (48%), moxifloxacin (44%) and metronidazole (32%). Resistance of ETBF to moxifloxacin (44%) and metronidazole is an emerging trend. Pulsed-field gel electrophoresis (PFGE) revealed that majority of the ETBF isolates are genetically diverse. In the dendrogram analysis, two clusters were identified, one with ETBF resistant to 5–8 antimicrobials and the other cluster with metronidazole and moxifloxacin susceptible isolates from diarrheal cases. To our knowledge, this is the first detailed report on ETBF from India indicating its clinical importance and molecular characteristics.
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Affiliation(s)
| | | | - Anirban Sarkar
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Ranjan K. Nandy
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | | | - Dipika Sur
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Bamkesh Manna
- National Institute of Cholera and Enteric Diseases, Kolkata, India
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Helicobacter pylori activates calpain via toll-like receptor 2 to disrupt adherens junctions in human gastric epithelial cells. Infect Immun 2011; 79:3887-94. [PMID: 21825064 DOI: 10.1128/iai.05109-11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Helicobacter pylori is a risk factor for the development of gastritis, gastroduodenal ulcers, and gastric adenocarcinoma. H. pylori-induced disruption of epithelial adherens junctions (AJs) is thought to promote the development of severe disease; however, the mechanisms whereby H. pylori alters AJ structure remain incompletely understood. The present study demonstrates that H. pylori infection in human patients is associated with elevated serum levels of an 80-kDa E-cadherin ectodomain, whose presence is independent of the presence of serum antibodies against CagA. In vitro, a heat-labile H. pylori surface component activates the host protease calpain in human gastric MKN45 cells independently of the virulence factors CagA and VacA. H. pylori-induced calpain activation results in cleavage of E-cadherin to produce a 100-kDa truncated form and induce relocalization of E-cadherin and β-catenin. Stimulation of MKN45 cells with the toll-like receptor 2 (TLR2) ligand P3C activated calpain and disrupted E-cadherin and β-catenin in a pattern similar to that induced by H. pylori. Inhibition of TLR2 prevented H. pylori-induced calpain activation and AJ disassembly. Together, these findings identify a novel pathway whereby H. pylori activates calpain via TLR2 to disrupt gastric epithelial AJ structure.
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Quantitative detection of enterotoxigenic Bacteroides fragilis subtypes isolated from children with and without diarrhea. J Clin Microbiol 2010; 49:416-8. [PMID: 20980581 DOI: 10.1128/jcm.01556-10] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A rapid real-time PCR (RT-PCR) approach was developed to detect the bft gene subtypes in Bacteroides fragilis isolated from fecal samples. DNA obtained from diarrhea (110) and nondiarrhea (150) samples was evaluated. Subtype 1 was observed in 9 (8.2%) diarrhea and 7 (4.7%) nondiarrhea samples. Subtype 2 was not detected in any DNA samples, and subtype 3 was observed in only 1 diarrhea sample. The presence of the bft-1 gene did not show any statistically significant differences between the groups of children. This technique could be used to evaluate a possible correlation between disease and the presence of B. fragilis enterotoxin.
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Evaluation of the prevalence of enterotoxigenic Bacteroides fragilis and the distribution bft gene subtypes in patients with diarrhea. Anaerobe 2010; 16:505-9. [PMID: 20709181 DOI: 10.1016/j.anaerobe.2010.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 07/14/2010] [Accepted: 08/05/2010] [Indexed: 11/22/2022]
Abstract
The aim of this study was to determine the prevalence of enterotoxigenic Bacteroides fragilis (ETBF) in the patients with diarrhea in our region and to assess the association between diarrhea and bft gene subtypes. The presence of ETBF and bft gene subtypes were investigated in 200 stool samples from patients with diarrhea, diagnosed as gastroenteritis, which were sent to Clinical Microbiology Laboratory at Zonguldak Karaelmas University, Training and Research Hospital and in 200 stool samples from age-matched healthy subjects between April 14, 2009 and October 28, 2009. Nested - polymerase chain reaction was used to detect the presence of bft gene directly from stool samples. The bft gene subtypes were determined by PCR in case of ETBF detection. The presence of bft gene was detected in 29 (15%) of patients and 27 (14%) of control group. bft-1 and bft-2 were found in 24 and five stool samples from 29 diarrheic patients with ETBF, respectively. Among 27 control patients with ETBF, bft-1 and bft-2 were found in 24 and three samples, respectively. No bft-3 subtypes were identified in our study. ETBF was found as a single pathogen in 9% of the patients with diarrhea, while there was an accompanying pathogen in 6% of the patients. The proportion of coinfection with another pathogen among ETBF positive patients was 38%. Cooccurance with ETBF was present in nine of 18 patients with Rotavirus and two of five patients with Entamoeba histolytica. In conclusion; there was no statistically significant difference between the prevalence of ETBF in diarrheal patients and that of the control group. When the patients and controls were compared for each age group, no statistically significant difference in ETBF rates was found. There was no significant difference between groups with respect to bft subtypes; bft-1 was identified as the most common subtype. The rate of coinfection of ETBF and Rotavirus was high.
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Abstract
Bacteroides fragilis is a minor component of the microbial flora of the intestine but the most frequent disease--causing anaerobe. Virulence characteristics are its capsule, which induces abscess formation, and the production of fragilysin, a Zn-metalloprotease. This toxin's action is to hydrolyze the extracellular domain of E-cadherin, the effect of which is to disrupt intercellular adhesion and thus increase permeability of the epithelium, causing intracellular redistribution of actin with morphologic changes to the cells and release of beta-catenin, which translocates to the nucleus and ultimately increases cellular proliferation. Clinically, enterotoxigenic B. fragilis is linked to secretory diarrhea, particularly in children. Preliminary evidence suggests that enterotoxigenic B. fragilis may also be linked to inflammatory bowel disease and colon cancer.
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Enterotoxigenic Bacteroides fragilis: a rogue among symbiotes. Clin Microbiol Rev 2009; 22:349-69, Table of Contents. [PMID: 19366918 DOI: 10.1128/cmr.00053-08] [Citation(s) in RCA: 254] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Enterotoxigenic Bacteroides fragilis (ETBF) strains are strains of B. fragilis that secrete a 20-kDa heat-labile zinc-dependent metalloprotease toxin termed the B. fragilis toxin (BFT). BFT is the only recognized virulence factor specific for ETBF. ETBF strains are associated with inflammatory diarrheal disease in children older than 1 year of age and in adults; limited data suggest an association of ETBF colonization with inflammatory bowel disease flare-ups and colorectal cancer. ETBF secretes one of three highly related BFT isoforms. The relationship between BFT isoform and disease expression is unknown. Although the mechanism of action of BFT is incompletely understood, available data suggest that BFT binds to a specific intestinal epithelial cell receptor, stimulating intestinal cell signal transduction pathways that result in cell morphology changes, cleavage of E-cadherin, reduced colonic barrier function, and increased epithelial cell proliferation and cytokine expression (such as the proinflammatory chemokine interleukin-8). Together, the data suggest that in some hosts, ETBF acts via secretion of BFT to induce colitis. However, the full spectrum of clinical disease related to ETBF and the impact of chronic ETBF colonization on the host remain to be defined.
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Miranda KR, Dias MF, Guimarães PLS, Boente RF, Pauer H, Ramos PZ, Falcão LS, Ferreira EDO, Balassiano IT, Ferreira LQ, Santos-Filho JD, Paula GRD, Antunes ENF, Avelar KES, Domingues RMCP. Enterotoxigenic and nontoxigenic Bacteroides fragilis strains isolated in Brazil. Mem Inst Oswaldo Cruz 2009; 103:734-5. [PMID: 19057827 DOI: 10.1590/s0074-02762008000700018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 09/26/2008] [Indexed: 11/22/2022] Open
Abstract
The presence of enterotoxigenic Bacteroides fragilis and nontoxigenic B. fragilis (NTBF) among 109 strains isolated from 1980-2008 in Brazil were investigated by PCR. One strain, representing 0.9% of the total analyzed strains, harbored the bft gene which was identified as bft-1 isoform based on PCR-RFLP and sequencing. Forty-nine strains (44.9%) exhibited the NTBF pattern III which possesses the flanking region required for pathogenicity island acquisition in which the bft gene is codified. These data reinforce the potential of B. fragilis as an emerging enteropathogen in our country.
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Affiliation(s)
- Karla R Miranda
- Laboratório de Biologia de Anaeróbios, Departamento de Microbiologia Médica, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
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Avila-Campos MJ, Liu C, Song Y, Rowlinson MC, Finegold SM. Determination of bft gene subtypes in Bacteroides fragilis clinical isolates. J Clin Microbiol 2007; 45:1336-8. [PMID: 17301286 PMCID: PMC1865835 DOI: 10.1128/jcm.02108-06] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A rapid multiplex PCR approach was developed to detect the bft gene subtypes in Bacteroides fragilis clinical isolates. This technique could be used to look at the epidemiology of enterotoxigenic strains of B. fragilis in clinical infections and whether there is a correlation between disease and the presence of B. fragilis enterotoxin.
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Affiliation(s)
- Mario J Avila-Campos
- Infectious Diseases Section (111F), VA Medical Center, West Los Angeles, CA 90073, USA
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