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Lu SSM, Rutegård M, Ahmed M, Häggström C, Gylfe Å, Harlid S, Van Guelpen B. Prediagnostic Prescription Antibiotics Use and Survival in Patients with Colorectal Cancer: A Swedish National Register-Based Study. Cancer Epidemiol Biomarkers Prev 2023; 32:1391-1401. [PMID: 37490284 PMCID: PMC10543975 DOI: 10.1158/1055-9965.epi-23-0340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/23/2023] [Accepted: 07/21/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND Antibiotics use is associated with higher colorectal cancer risk, but little is known regarding any potential effects on survival. METHODS We conducted a nationwide cohort study, using complete-population data from Swedish national registers between 2005 and 2020, to investigate prediagnostic prescription antibiotics use in relation to survival in colorectal cancer patients. RESULTS We identified 36,061 stage I-III and 11,242 stage IV colorectal cancer cases diagnosed between 2010 and 2019. For stage I-III, any antibiotics use (binary yes/no variable) was not associated with overall or cancer-specific survival. Compared with no use, moderate antibiotics use (total 11-60 days) was associated with slightly better cancer-specific survival [adjusted HR (aHR) = 0.93; 95% confidence interval (CI), 0.86-0.99)], whereas very high use (>180 days) was associated with worse survival [overall survival (OS) aHR = 1.42; 95% CI, 1.26-1.60, cancer-specific survival aHR = 1.31; 95% CI, 1.10-1.55]. In analyses by different antibiotic types, although not statistically significant, worse survival outcomes were generally observed across several antibiotics, particularly macrolides and/or lincosamides. In stage IV colorectal cancer, inverse relationships between antibiotics use and survival were noted. CONCLUSIONS Overall, our findings do not support any substantial detrimental effects of prediagnostic prescription antibiotics use on cancer-specific survival after colorectal cancer diagnosis, with the possible exception of very high use in stage I-III colorectal cancer. Further investigation is warranted to confirm and understand these results. IMPACT Although the study findings require confirmation, physicians probably do not need to factor in prediagnostic prescription antibiotics use in prognosticating patients with colorectal cancer.
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Affiliation(s)
- Sai San Moon Lu
- Department of Radiation Sciences, Oncology unit, Umeå University, Umeå, Sweden
| | - Martin Rutegård
- Department of Surgical and Perioperative Sciences, Surgery, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Maghfoor Ahmed
- Department of Radiation Sciences, Oncology unit, Umeå University, Umeå, Sweden
| | - Christel Häggström
- Department of Public Health and Clinical Medicine, Registry Centre North, Umeå University, Umeå, Sweden
| | - Åsa Gylfe
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
- Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Sophia Harlid
- Department of Radiation Sciences, Oncology unit, Umeå University, Umeå, Sweden
| | - Bethany Van Guelpen
- Department of Radiation Sciences, Oncology unit, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
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Detection of human pathogenic bacteria in rectal DNA samples from Zalophus californianus in the Gulf of California, Mexico. Sci Rep 2022; 12:14859. [PMID: 36050340 PMCID: PMC9434536 DOI: 10.1038/s41598-022-18903-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 08/22/2022] [Indexed: 12/05/2022] Open
Abstract
Human intrusions into undisturbed wildlife areas greatly contribute to the emergence of infectious diseases. To minimize the impacts of novel emerging infectious diseases (EIDs) on human health, a comprehensive understanding of the microbial species that reside within wildlife species is required. The Gulf of California (GoC) is an example of an undisturbed ecosystem. However, in recent decades, anthropogenic activities within the GoC have increased. Zalophus californianus has been proposed as the main sentinel species in the GoC; hence, an assessment of sea lion bacterial microbiota may reveal hidden risks for human health. We evaluated the presence of potential human pathogenic bacterial species from the gastrointestinal (GI) tracts of wild sea lions through a metabarcoding approach. To comprehensively evaluate this bacterial consortium, we considered the genetic information of six hypervariable regions of 16S rRNA. Potential human pathogenic bacteria were identified down to the species level by integrating the RDP and Pplacer classifier outputs. The combined genetic information from all analyzed regions suggests the presence of at least 44 human pathogenic bacterial species, including Shigella dysenteriae and Bacillus anthracis. Therefore, the risks of EIDs from this area should be not underestimated.
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Yekani M, Rezaee MA, Beheshtirouy S, Baghi HB, Bazmani A, Farzinazar A, Memar MY, Sóki J. Carbapenem resistance in Bacteroides fragilis: A review of molecular mechanisms. Anaerobe 2022; 76:102606. [PMID: 35738484 DOI: 10.1016/j.anaerobe.2022.102606] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/10/2022] [Accepted: 06/16/2022] [Indexed: 11/28/2022]
Abstract
Carbapenems are an applicable subclass of β-lactam drugs in the antibiotic therapy of anaerobic infections, especially for poly-microbial cases, due to their broad antimicrobial spectrum on aerobic and anaerobic bacteria. Bacteroides fragilis is the most commonly recovered anaerobic bacteria in the clinical laboratories from mono- and poly-microbial infections. B. fragilis is relatively non-susceptible to different antibiotics, including β-lactams, tetracyclines, fluoroquinolones, and macrolides. Carbapenems are among the most effective drugs against B. fragilis strains with high-level resistance to different antibiotics. Increased antibiotic resistance of B. fragilis strains has been reported following the overuse of an antimicrobial agent. Earlier contact with carbapenems is linked with increased resistance to them that limits the options for treatment of B. fragilis caused infections, especially in cases caused by multidrug-resistant strains. Several molecular mechanisms of resistance to carbapenems have been described for different carbapenem-resistant bacteria. Understanding the mechanisms of resistance to antimicrobial agents is necessary for selecting alternative antimicrobial agents and the application of control strategies. In the present study, we reviewed the mechanisms contributing to resistance to carbapenems in B. fragilis strains.
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Affiliation(s)
- Mina Yekani
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran
| | | | - Samad Beheshtirouy
- Cardiothoracic Department, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Ahad Bazmani
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Abbas Farzinazar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Yousef Memar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - József Sóki
- Institute of Medical Microbiology, Albert Szent-Györgyi Health Centre and School of of Medicine, University of Szeged, Szeged, Hungary.
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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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Rocha ER, Bergonia HA, Gerdes S, Jeffrey Smith C. Bacteroides fragilis requires the ferrous-iron transporter FeoAB and the CobN-like proteins BtuS1 and BtuS2 for assimilation of iron released from heme. Microbiologyopen 2019; 8:e00669. [PMID: 29931811 PMCID: PMC6460266 DOI: 10.1002/mbo3.669] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/13/2018] [Accepted: 05/07/2018] [Indexed: 12/17/2022] Open
Abstract
The intestinal commensal and opportunistic anaerobic pathogen Bacteroides fragilis has an essential requirement for both heme and free iron to support growth in extraintestinal infections. In the absence of free iron, B. fragilis can utilize heme as the sole source of iron. However, the mechanisms to remove iron from heme are not completely understood. In this study, we show that the inner membrane ferrous iron transporter ∆feoAB mutant strain is no longer able to grow with heme as the sole source of iron. Genetic complementation with the feoAB gene operon completely restored growth. Our data indicate that iron is removed from heme in the periplasmic space, and the released iron is transported by the FeoAB system. Interestingly, when B. fragilis utilizes iron from heme, it releases heme-derived porphyrins by a dechelatase activity which is upregulated under low iron conditions. This is supported by the findings showing that formation of heme-derived porphyrins in the ∆feoAB mutant and the parent strain increased 30-fold and fivefold (respectively) under low iron conditions compared to iron replete conditions. Moreover, the btuS1 btuS2 double-mutant strain (lacking the predicted periplasmic, membrane anchored CobN-like proteins) also showed growth defect with heme as the sole source of iron, suggesting that BtuS1 and BtuS2 are involved in heme-iron assimilation. Though the dechelatase mechanism remains uncharacterized, assays performed in bacterial crude extracts show that BtuS1 and BtuS2 affect the regulation of the dechelatase-specific activities in an iron-dependent manner. These findings suggest that the mechanism to extract iron from heme in Bacteroides requires a group of proteins, which spans the periplasmic space to make iron available for cellular functions.
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Affiliation(s)
- Edson R. Rocha
- Department of Microbiology and ImmunologyBrody School of MedicineGreenvilleNorth Carolina
| | - Hector A. Bergonia
- Iron and Heme CoreDivision of HematologyUniversity of Utah School of MedicineSalt Lake CityUtah
| | | | - Charles Jeffrey Smith
- Department of Microbiology and ImmunologyBrody School of MedicineGreenvilleNorth Carolina
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Kierzkowska M, Majewska A, Szymanek-Majchrzak K, Sawicka-Grzelak A, Mlynarczyk A, Mlynarczyk G. The presence of antibiotic resistance genes and bft genes as well as antibiotic susceptibility testing of Bacteroides fragilis strains isolated from inpatients of the Infant Jesus Teaching Hospital, Warsaw during 2007-2012. Anaerobe 2019; 56:109-115. [PMID: 30844502 DOI: 10.1016/j.anaerobe.2019.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 01/05/2023]
Abstract
The purpose of this study was to assess drug susceptibility of clinical B. fragilis strains and to determine any correlation between drug resistance and the presence of specific genes. Antimicrobial susceptibility was assessed using E-tests. All isolates were analyzed with the PCR technique for the presence of antibiotic resistance genes (cepA, cfxA, cfiA, ermF, ermB, ermG, nim), insertion sequences elements (IS1186, IS1187, IS1188, IS942), and enterotoxin-encoding genes (bft). Susceptibility tests yielded the following rates of resistance to the evaluated antibiotics: penicillin G (100%), clindamycin (22.5%), cefoxitin (6.3%), amoxicillin/clavulanic acid (1.8%). All strain were susceptible to imipenem, and metronidazole. The following antibiotic resistance genes were detected in the evaluated isolates: cepA (in 96.4% of isolates), cfxA (in 12.6%), cfiA (in 1.8%), and ermF (in 25.2%). Genes ermB, ermG, and nim were not found. The presence of the cepA gene showed no correlation with the penicillin G MIC. However, we observed a high correlation between cefoxitin MIC values and the presence of gene cfxA as well as a nearly complete correlation between clindamycin MIC values and the presence of gene ermF. The presence of a bft gene was detected in 14.4% of the analyzed B. fragilis isolates; with the bft-1 allele found in 75%, bft-2 in 25%, and bft-3 in none of the isolates. Antibiotic susceptibility profiles of enterotoxin gene-positive isolates in our study did not differ from those of enterotoxin gene-negative isolates.
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Affiliation(s)
- Marta Kierzkowska
- Chair and Department of Medical Microbiology, Medical University of Warsaw, Chalubinskiego 5 Str., 02-004, Warsaw, Poland; Department of Medical Microbiology, The Infant Jesus Teaching Hospital, Lindleya 4 Str., 02-004, Warsaw, Poland
| | - Anna Majewska
- Chair and Department of Medical Microbiology, Medical University of Warsaw, Chalubinskiego 5 Str., 02-004, Warsaw, Poland; Department of Medical Microbiology, The Infant Jesus Teaching Hospital, Lindleya 4 Str., 02-004, Warsaw, Poland.
| | - Ksenia Szymanek-Majchrzak
- Chair and Department of Medical Microbiology, Medical University of Warsaw, Chalubinskiego 5 Str., 02-004, Warsaw, Poland; Department of Medical Microbiology, The Infant Jesus Teaching Hospital, Lindleya 4 Str., 02-004, Warsaw, Poland
| | - Anna Sawicka-Grzelak
- Chair and Department of Medical Microbiology, Medical University of Warsaw, Chalubinskiego 5 Str., 02-004, Warsaw, Poland; Department of Medical Microbiology, The Infant Jesus Teaching Hospital, Lindleya 4 Str., 02-004, Warsaw, Poland
| | - Andrzej Mlynarczyk
- Department of Medical Microbiology, The Infant Jesus Teaching Hospital, Lindleya 4 Str., 02-004, Warsaw, Poland
| | - Grazyna Mlynarczyk
- Chair and Department of Medical Microbiology, Medical University of Warsaw, Chalubinskiego 5 Str., 02-004, Warsaw, Poland; Department of Medical Microbiology, The Infant Jesus Teaching Hospital, Lindleya 4 Str., 02-004, Warsaw, Poland
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Huang L, Gao R, Yu N, Zhu Y, Ding Y, Qin H. Dysbiosis of gut microbiota was closely associated with psoriasis. SCIENCE CHINA-LIFE SCIENCES 2018; 62:807-815. [PMID: 30264198 DOI: 10.1007/s11427-018-9376-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Accepted: 08/09/2018] [Indexed: 02/06/2023]
Abstract
Psoriasis is an autoimmune disease and gut microbiota participate in the establishment of intestinal immunity. This study was performed to identify the fecal microbial composition of psoriasis patients, and investigated the influence of subgroup (type and severity) on the fecal microbial composition, and to define the key microbiota in the pathogenesis of psoriasis. Fecal samples from 35 psoriasis patients and 27 healthy controls were sequenced by 16S rRNA and then analyzed by informatics methods. We found that the microbiota of the psoriasis group differed from that of the heathy group. The relative abundances of Firmicutes and Bacteroidetes were inverted at the phylum level, and 16 kinds of phylotype at the genus level were found with significant difference. No microbial diversity and composition alteration were observed among the four types of psoriasis. The microbiota of psoriasis patients in the severe state differs from those of psoriasis patients with more mild conditions and also the healthy controls. The veillonella in fecal microbiota showed a positive relationship with h-CRP in blood. This research proved that psoriasis patients have a significant disturbed microbiota profiles. Further study of psoriasis based on microbiota may provide novel insights into the pathogenesis of psoriasis and more evidence for the prevention and treatment of psoriasis.
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Affiliation(s)
- Linsheng Huang
- Shanghai Clinical College, Anhui Medical University, Shanghai, 200072, China.,Department of General Surgery, Shanghai Tenth People's Hospital Affiliated to Tongji University, Shanghai, 200072, China
| | - Renyuan Gao
- Department of General Surgery, Shanghai Tenth People's Hospital Affiliated to Tongji University, Shanghai, 200072, China
| | - Ning Yu
- Department of Dermatology, Shanghai Dermatology Hospital, Shanghai, 200043, China
| | - Yefei Zhu
- Department of General Surgery, Shanghai Tenth People's Hospital Affiliated to Tongji University, Shanghai, 200072, China
| | - Yangfeng Ding
- Department of Dermatology, Shanghai Dermatology Hospital, Shanghai, 200043, China.
| | - Huanlong Qin
- Shanghai Clinical College, Anhui Medical University, Shanghai, 200072, China. .,Department of General Surgery, Shanghai Tenth People's Hospital Affiliated to Tongji University, Shanghai, 200072, China.
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Søgaard KK, Farkas DK, Søgaard M, Schønheyder HC, Thomsen RW, Sørensen HT. Gram-negative bacteremia as a clinical marker of occult malignancy. J Infect 2016; 74:153-162. [PMID: 27838520 DOI: 10.1016/j.jinf.2016.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 09/19/2016] [Accepted: 09/28/2016] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Gram-negative bacteremia may be a harbinger of occult cancer. We examined the risk of cancer following hospitalization with bacteremia. METHODS Using medical databases, we conducted a nationwide population-based cohort study of all Danes with a discharge diagnosis of Gram-negative bacteremia during 1994-2013. We calculated absolute risks and standardized incidence ratios (SIRs) of cancer, comparing the observed risk to that expected in the general population. RESULTS We observed 1379 cancers vs. 988 expected among 11,753 patients with Gram-negative bacteremia, corresponding to an overall SIR of 1.40 (95% confidence interval (CI): 1.32-1.47). During the first 6 months following the bacteremia diagnosis, the SIR for cancer was 3.33-fold (95% CI: 2.99-3.69) increased, corresponding to an absolute risk of 3.05%. The increased risk stemmed mainly from higher than expected occurrence of gastrointestinal cancer (3- to 13-fold higher), genitourinary cancer (4- to 10-fold higher), non-Hodgkin lymphoma (5-fold higher), non-specified metastatic cancer (5-fold higher), and breast and lung cancer (2-fold higher). The 6-12 months SIR for any cancer was 1.46 (95% CI: 1.22-1.72), and beyond 1 year of follow-up, the SIR declined to 1.13 (95% CI: 1.05-1.20). CONCLUSIONS Gram-negative bacteremia is a clinical marker of occult cancer.
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Affiliation(s)
- Kirstine K Søgaard
- Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, 8200 Aarhus N, Denmark.
| | - Dóra K Farkas
- Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, 8200 Aarhus N, Denmark
| | - Mette Søgaard
- Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, 8200 Aarhus N, Denmark
| | - Henrik C Schønheyder
- Department of Clinical Microbiology, Aalborg University Hospital, Mølleparkvej 10, 9000 Aalborg, Denmark; Department of Clinical Medicine, Aalborg University, Søndre Skovvej 15, 9000 Aalborg, Denmark
| | - Reimar W Thomsen
- Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, 8200 Aarhus N, Denmark
| | - Henrik T Sørensen
- Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, 8200 Aarhus N, Denmark
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Brim H, Yooseph S, Zoetendal EG, Lee E, Torralbo M, Laiyemo AO, Shokrani B, Nelson K, Ashktorab H. Microbiome analysis of stool samples from African Americans with colon polyps. PLoS One 2013; 8:e81352. [PMID: 24376500 PMCID: PMC3869648 DOI: 10.1371/journal.pone.0081352] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 10/11/2013] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Colonic polyps are common tumors occurring in ~50% of Western populations with ~10% risk of malignant progression. Dietary agents have been considered the primary environmental exposure to promote colorectal cancer (CRC) development. However, the colonic mucosa is permanently in contact with the microbiota and its metabolic products including toxins that also have the potential to trigger oncogenic transformation. AIM To analyze fecal DNA for microbiota composition and functional potential in African Americans with pre-neoplastic lesions. MATERIALS & METHODS We analyzed the bacterial composition of stool samples from 6 healthy individuals and 6 patients with colon polyps using 16S ribosomal RNA-based phylogenetic microarray; the Human intestinal Tract Chip (HITChip) and 16S rRNA gene barcoded 454 pyrosequencing. The functional potential was determined by sequence-based metagenomics using 454 pyrosequencing. RESULTS Fecal microbiota profiling of samples from the healthy and polyp patients using both a phylogenetic microarraying (HITChip) and barcoded 454 pyrosequencing generated similar results. A distinction between both sets of samples was only obtained when the analysis was performed at the sub-genus level. Most of the species leading to the dissociation were from the Bacteroides group. The metagenomic analysis did not reveal major differences in bacterial gene prevalence/abundances between the two groups even when the analysis and comparisons were restricted to available Bacteroides genomes. CONCLUSION This study reveals that at the pre-neoplastic stages, there is a trend showing microbiota changes between healthy and colon polyp patients at the sub-genus level. These differences were not reflected at the genome/functions levels. Bacteria and associated functions within the Bacteroides group need to be further analyzed and dissected to pinpoint potential actors in the early colon oncogenic transformation in a large sample size.
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Affiliation(s)
- Hassan Brim
- Department of Pathology, Department of Medicine and Cancer Center, Howard University, College of Medicine, Washington, District of Columbia, United States of America
- * E-mail:
| | - Shibu Yooseph
- JCVI, San Diego, California, United States of America
| | - Erwin G. Zoetendal
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
| | - Edward Lee
- Department of Pathology, Department of Medicine and Cancer Center, Howard University, College of Medicine, Washington, District of Columbia, United States of America
| | | | - Adeyinka O. Laiyemo
- Department of Pathology, Department of Medicine and Cancer Center, Howard University, College of Medicine, Washington, District of Columbia, United States of America
| | - Babak Shokrani
- Department of Pathology, Department of Medicine and Cancer Center, Howard University, College of Medicine, Washington, District of Columbia, United States of America
| | - Karen Nelson
- JCVI, Rockville, Maryland, United States of America
| | - Hassan Ashktorab
- Department of Pathology, Department of Medicine and Cancer Center, Howard University, College of Medicine, Washington, District of Columbia, United States of America
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Lobo LA, Jenkins AL, Jeffrey Smith C, Rocha ER. Expression of Bacteroides fragilis hemolysins in vivo and role of HlyBA in an intra-abdominal infection model. Microbiologyopen 2013; 2:326-37. [PMID: 23441096 PMCID: PMC3633356 DOI: 10.1002/mbo3.76] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/22/2013] [Accepted: 01/28/2013] [Indexed: 01/01/2023] Open
Abstract
Bacteroides fragilis is the most frequent opportunistic pathogen isolated from anaerobic infections. However, there is a paucity of information regarding the genetic and molecular aspects of gene expression of its virulence factors during extra-intestinal infections. A potential virulence factor that has received little attention is the ability of B. fragilis to produce hemolysins. In this study, an implanted perforated table tennis "ping-pong" ball was used as an intra-abdominal artificial abscess model in the rat. This procedure provided sufficient infected exudate for gene expression studies in vivo. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to quantify the relative expression of hlyA, hlyB, hlyC, hlyD, hlyE, hlyF, hlyG, and hlyIII mRNAs. The hlyA mRNA was induced approximately sixfold after 4 days postinfection compared with the mRNA levels in the inoculum culture prior to infection. The hlyB mRNA increased approximately sixfold after 4 days and 12-fold after 8 days postinfection. Expression of hlyC mRNA increased sixfold after 1 day, 45-fold after 4 days, and 16-fold after 8 days postinfection, respectively. The hlyD and hlyE mRNAs were induced approximately 40-fold and 30-fold, respectively, after 4-days postinfection. The hlyF expression increased approximately threefold after 4-days postinfection. hlyG was induced approximately fivefold after 4 and 8 days postinfection. The hlyIII mRNA levels had a steady increase of approximately four-, eight-, and 12-fold following 1, 4, and 8 days postinfection, respectively. These findings suggest that B. fragilis hemolysins are induced and differentially regulated in vivo. Both parent and hlyBA mutant strains reached levels of approximately 3-8 × 10(9) cfu/mL after 1 day postinfection. However, the hlyBA mutant strain lost 2 logs in viable cell counts compared with the parent strain after 8 days postinfection. This is the first study showing HlyBA is a virulence factor which plays a role in B. fragilis survival in an intra-abdominal abscess model.
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Affiliation(s)
- Leandro A Lobo
- Department of Microbiology and Immunology, East Carolina University Brody School of Medicine, Greenville, North Carolina 27834, USA
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Kipanyula MJ, Seke Etet PF, Vecchio L, Farahna M, Nukenine EN, Nwabo Kamdje AH. Signaling pathways bridging microbial-triggered inflammation and cancer. Cell Signal 2012; 25:403-16. [PMID: 23123499 DOI: 10.1016/j.cellsig.2012.10.014] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 10/26/2012] [Indexed: 02/06/2023]
Abstract
Microbial-triggered inflammation protects against pathogens and yet can paradoxically cause considerable secondary damage to host tissues that can result in tissue fibrosis and carcinogenesis, if persistent. In addition to classical pathogens, gut microbiota bacteria, i.e. a group of mutualistic microorganisms permanently inhabiting the gastrointestinal tract and which plays a key role in digestion, immunity, and cancer prevention, can induce inflammation-associated cancer following the alterations of their microenvironment. Emerging experimental evidence indicates that microbiota members like Escherichia coli and several other genotoxic and mutagenic pathogens can cause DNA damage in various cell types. In addition, the inflammatory response induced by chronic infections with pathogens like the microbiota members Helicobacter spp., which have been associated with liver, colorectal, cervical cancers and lymphoma, for instance, can also trigger carcinogenic processes. A microenvironment including active immune cells releasing high amounts of inflammatory signaling molecules can favor the carcinogenic transformation of host cells. Pivotal molecules released during immune response such as the macrophage migration inhibitory factor (MMIF) and the reactive oxygen and nitrogen species' products superoxide and peroxynitrite, can further damage DNA and cause the accumulation of oncogenic mutations, whereas pro-inflammatory cytokines, adhesion molecules, and growth factors may create a microenvironment promoting neoplastic cell survival and proliferation. Recent findings on the implication of inflammatory signaling pathways in microbial-triggered carcinogenesis as well as the possible role of microbiota modulation in cancer prevention are herein summarized and discussed.
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Affiliation(s)
- Maulilio John Kipanyula
- Department of Veterinary Anatomy, Sokoine University of Agriculture, P.O. Box 3016, Chuo Kikuu, Morogoro, Tanzania
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Nguyen M, Vedantam G. Mobile genetic elements in the genus Bacteroides, and their mechanism(s) of dissemination. Mob Genet Elements 2011; 1:187-196. [PMID: 22479685 DOI: 10.4161/mge.1.3.18448] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 10/15/2011] [Accepted: 10/17/2011] [Indexed: 01/25/2023] Open
Abstract
Bacteroides spp organisms, the predominant commensal bacteria in the human gut have become increasingly resistant to many antibiotics. They are now also considered to be reservoirs of antibiotic resistance genes due to their capacity to harbor and disseminate these genes via mobile transmissible elements that occur in bewildering variety. Gene dissemination occurs within and from Bacteroides spp primarily by conjugation, the molecular mechanisms of which are still poorly understood in the genus, even though the need to prevent this dissemination is urgent. One current avenue of research is thus focused on interventions that use non-antibiotic methodologies to prevent conjugation-based DNA transfer.
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Affiliation(s)
- Mai Nguyen
- Section of Digestive Diseases and Nutrition; University of Illinois; Chicago, IL USA
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