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Sardzikova S, Andrijkova K, Svec P, Beke G, Klucar L, Minarik G, Bielik V, Kolenova A, Soltys K. Gut diversity and the resistome as biomarkers of febrile neutropenia outcome in paediatric oncology patients undergoing hematopoietic stem cell transplantation. Sci Rep 2024; 14:5504. [PMID: 38448687 PMCID: PMC10918076 DOI: 10.1038/s41598-024-56242-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/04/2024] [Indexed: 03/08/2024] Open
Abstract
The gut microbiota of paediatric oncology patients undergoing a conditioning regimen before hematopoietic stem cell transplantation is recently considered to play role in febrile neutropenia. Disruption of commensal microbiota and evolution of opportune pathogens community carrying a plethora of antibiotic-resistance genes play crucial role. However, the impact, predictive role and association of patient´s gut resistome in the course of the therapy is still to be elucidated. We analysed gut microbiota composition and resistome of 18 paediatric oncology patients undergoing hematopoietic stem cell transplantation, including 12 patients developing febrile neutropenia, hospitalized at The Bone Marrow Transplantation Unit of the National Institute of Children´s disease in Slovak Republic and healthy individuals (n = 14). Gut microbiome of stool samples obtained in 3 time points, before hematopoietic stem cell transplantation (n = 16), one week after hematopoietic stem cell transplantation (n = 16) and four weeks after hematopoietic stem cell transplantation (n = 14) was investigated using shotgun metagenome sequencing and bioinformatical analysis. We identified significant decrease in alpha-diversity and nine antibiotic-resistance genes msr(C), dfrG, erm(T), VanHAX, erm(B), aac(6)-aph(2), aph(3)-III, ant(6)-Ia and aac(6)-Ii, one week after hematopoietic stem cell transplantation associated with febrile neutropenia. Multidrug-resistant opportune pathogens of ESKAPE, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli found in the gut carried the significant subset of patient's resistome. Over 50% of patients treated with trimethoprim/sulfamethoxazole, piperacillin/tazobactam and amikacin carried antibiotic-resistance genes to applied treatment. The alpha diversity and the resistome of gut microbiota one week after hematopoietic stem cell transplantation is relevant predictor of febrile neutropenia outcome after hematopoietic stem cell transplantation. Furthermore, the interindividual diversity of multi-drug resistant opportunistic pathogens with variable portfolios of antibiotic-resistance genes indicates necessity of preventive, personalized approach.
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Affiliation(s)
- Sara Sardzikova
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Kristina Andrijkova
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Peter Svec
- Department of Paediatric Haematology and Oncology, Children's Haematology and Oncology Clinic and Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | - Gabor Beke
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Lubos Klucar
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | | | - Viktor Bielik
- Department of Biological and Medical Science, Faculty of Physical Education and Sport, Comenius University in Bratislava, Bratislava, Slovakia
| | - Alexandra Kolenova
- Department of Paediatric Haematology and Oncology, Children's Haematology and Oncology Clinic and Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | - Katarina Soltys
- Department of Microbiology and Virology, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia.
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Diversity of genomic clusters and CfiA/cfiA alleles in Bacteroides fragilis isolates from human and animals. Anaerobe 2022; 75:102567. [DOI: 10.1016/j.anaerobe.2022.102567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/28/2022] [Accepted: 04/09/2022] [Indexed: 11/23/2022]
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Liang H, Wang F, Mu R, Huang J, Zhao R, Li X, Yu K, Li B. Metagenomics analysis revealing the occurrence of antibiotic resistome in salt lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 790:148262. [PMID: 34380279 DOI: 10.1016/j.scitotenv.2021.148262] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 06/13/2023]
Abstract
Although antimicrobial resistance genes (ARGs) in dozens of environments have been well documented, the distribution of ARGs in salt lake ecosystems has been less intensively investigated. In this study, the broad-spectrum ARG profiles, microbial community composition and the comprehensive associations between microbiome and antimicrobial resistome in four salt lakes were investigated using a metagenomic approach. A total of 175 ARG subtypes affiliated with 19 ARG types were detected, and ARGs conferring resistance to multidrug, bacitracin, and macrolide-lincosamide-streptogramin (MLS) accounted for 71.2% of the total ARG abundance. However, the abundance of ARGs significantly decreased with the increasing salinity in the lakes. Both ARG profiles and microbial community structure presented remarkable discrepancies in different lakes, as well as in different sample types. Microbes such as genera Azoarcus, Aeromonas, Pseudomonas, and Kocuria, significantly co-occurred with multiple ARGs, indicating that these bacteria are potential ARG hosts in salt lake ecosystems. Collectively, this work provides new insights into the occurrence and distribution of ARGs in salt lake ecosystems.
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Affiliation(s)
- Hebin Liang
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Fan Wang
- School of Atmospheric Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China; Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Zhuhai 519082, China
| | - Rong Mu
- School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Jin Huang
- Shenzhen Environmental Science and New Energy Laboratory, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Renxin Zhao
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xiaoyan Li
- Shenzhen Environmental Science and New Energy Laboratory, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Ke Yu
- School of Environment and Energy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
| | - Bing Li
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
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Yang J, Li T, Feng T, Yu Q, Su W, Zhou R, Li X, Li H. Water volume influences antibiotic resistomes and microbiomes during fish corpse decomposition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 789:147977. [PMID: 34052485 DOI: 10.1016/j.scitotenv.2021.147977] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/07/2021] [Accepted: 05/19/2021] [Indexed: 06/12/2023]
Abstract
Corpse decomposition may cause serious pollution (e.g., releasing antibiotic resistance genes) to the water environment, thereby threatening public health. However, whether antibiotic resistance genes (ARGs) and microbiomes are affected by different water volumes during carcass decomposition remains unknown. Here, we investigated the effects of large/small water volumes on microbial communities and ARGs during fish cadaver decomposition by 16S rRNA high-throughput sequencing and high-throughput quantitative PCR. The results showed that the large water volume almost eliminated the effects of corpse decomposition on pH, total organic carbon (TOC), and total nitrogen (TN). When the water volume enlarged by 62.5 fold, the relative abundances of some ARGs resisting tetracycline and sulfonamide during carcass decomposition decreased by 217 fold on average, while there was also a mean 5267 fold increase of vancomycin resistance genes. Compared with the control group, the enriched types of ARGs varied between the large and small volume. Water volume, mobile genetic elements, and carcass decomposition were the most important factors affecting ARG profiles. Many opportunistic pathogens (like Bacteroides and Comamonas) were enriched in the corpse group. Bacteroides and Comamonas may be potential hosts of ARGs, indicating the potential for the spread of ARGs to humans by water pathogenic bacteria. This research highlights that the "dilution effect" can contribute to eliminating this adverse effect during corpse decomposition to a certain extent. It may provide references for environmental governance and public health.
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Affiliation(s)
- Jiawei Yang
- School of Public Health, Lanzhou University, Lanzhou 730000, China
| | - Tongtong Li
- Department of Applied Biology, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Tianshu Feng
- School of Public Health, Lanzhou University, Lanzhou 730000, China
| | - Qiaoling Yu
- School of Public Health, Lanzhou University, Lanzhou 730000, China
| | - Wanghong Su
- School of Public Health, Lanzhou University, Lanzhou 730000, China
| | - Rui Zhou
- School of Public Health, Lanzhou University, Lanzhou 730000, China
| | - Xiangzhen Li
- Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China.
| | - Huan Li
- School of Public Health, Lanzhou University, Lanzhou 730000, China; Center for Grassland Microbiome, Lanzhou University, Lanzhou 730000, China.
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Thomas C, Gwenin CD. The Role of Nitroreductases in Resistance to Nitroimidazoles. BIOLOGY 2021; 10:388. [PMID: 34062712 PMCID: PMC8147198 DOI: 10.3390/biology10050388] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/04/2021] [Accepted: 02/10/2021] [Indexed: 01/14/2023]
Abstract
Antimicrobial resistance is a major challenge facing modern medicine, with an estimated 700,000 people dying annually and a global cost in excess of $100 trillion. This has led to an increased need to develop new, effective treatments. This review focuses on nitroimidazoles, which have seen a resurgence in interest due to their broad spectrum of activity against anaerobic Gram-negative and Gram-positive bacteria. The role of nitroreductases is to activate the antimicrobial by reducing the nitro group. A decrease in the activity of nitroreductases is associated with resistance. This review will discuss the resistance mechanisms of different disease organisms, including Mycobacterium tuberculosis, Helicobacter pylori and Staphylococcus aureus, and how these impact the effectiveness of specific nitroimidazoles. Perspectives in the field of nitroimidazole drug development are also summarised.
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Affiliation(s)
- Carol Thomas
- School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK;
| | - Christopher D. Gwenin
- Department of Chemistry, Xi’an Jiaotong-Liverpool University, 111 Ren’ai Road, Suzhou Industrial Park, Suzhou 215123, China
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Kozhakhmetova S, Zholdybayeva E, Tarlykov P, Atavliyeva S, Syzdykov T, Daniyarov A, Mukhtarova K, Ramankulov Y. Determinants of resistance in Bacteroides fragilis strain BFR_KZ01 isolated from a patient with peritonitis in Kazakhstan. J Glob Antimicrob Resist 2021; 25:1-4. [PMID: 33667704 DOI: 10.1016/j.jgar.2021.02.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/28/2021] [Accepted: 02/19/2021] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Bacteroides fragilis is one of the most important human anaerobic pathogens often found in various clinical infections. The purpose of this study was to determine the susceptibility of a B. fragilis clinical strain (BFR_KZ01) from Kazakhstan to the most commonly used anti-anaerobic drugs at the local level and to detect genes associated with resistance to these antibiotics. METHODS Species identification of the bacterial isolate was performed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) and 16S rRNA gene sequencing. Susceptibility to broad-spectrum antibiotics (metronidazole, meropenem, ciprofloxacin, clindamycin and tetracycline) most commonly used for the treatment of intra-abdominal infections (IAIs) was determined. Mass spectra groups essential for identifying cfiA-positive strains among clinical isolates were studied using ClinProTools 3.0.22 software. An Ion Torrent PGM™ platform was used for whole-genome sequencing (WGS) of the studied isolate. RESULTS The resulting WGS data of strain BFR_KZ01 was submitted to GenBank. In total, 5300 coding sequences (CDSs) and 69 RNA genes were determined. Analysis of the whole-genome data revealed that the studied strain harbours cfiA, nimB, tetQ and gyrA genes conferring resistance to key drugs used in treatment of the IAIs. MALDI-TOF/MS analysis assigned strain BFR_KZ01 to Group II (cfiA-positive); however, BFR_KZ01 was phenotypically sensitive to meropenem (mean MIC, 1.3 mg/L). CONCLUSION Determinants of drug resistance in strain BFR_KZ01 were identified. It was revealed that B. fragilis strain BFR_KZ01 from Kazakhstan is multidrug-resistant since it carries nimB, tetQ and gyrA genes conferring resistance to metronidazole, tetracycline and ciprofloxacin.
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Affiliation(s)
| | | | - Pavel Tarlykov
- RSE National Center for Biotechnology, Nur-Sultan, Z05K8D5, Kazakhstan
| | - Sabina Atavliyeva
- RSE National Center for Biotechnology, Nur-Sultan, Z05K8D5, Kazakhstan
| | | | - Asset Daniyarov
- RSE National Center for Biotechnology, Nur-Sultan, Z05K8D5, Kazakhstan; Laboratory of Bioinformatics and Systems Biology, Center for Life Sciences, National Laboratory Astana, Nazarbayev University, 53 Kabanbay Batyr Ave, Nur-Sultan, 010000, Kazakhstan
| | - Kymbat Mukhtarova
- RSE National Center for Biotechnology, Nur-Sultan, Z05K8D5, Kazakhstan
| | - Yerlan Ramankulov
- RSE National Center for Biotechnology, Nur-Sultan, Z05K8D5, Kazakhstan; School of Science and Technology, Nazarbayev University, 53 Kabanbay Batyr Ave., Nur-Sultan, 010000, Kazakhstan
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7
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Genotyping of multi drug resistant Bacteroides fragilis group of clinical isolates from mangalore, south India. Indian J Med Microbiol 2020; 39:19-23. [PMID: 33610251 DOI: 10.1016/j.ijmmb.2020.10.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
INTRODUCTION Bacteroides fragilis group, the most encountered anaerobic bacterium is emerging with resistance to antibiotics. This study explores the antibiogram and occurrence of resistance genes in isolates of B fragilis group from clinical samples. METHOD In this study the antimicrobial susceptibility test was done using commercially available E strip test and the results were recorded according to CLSI guidelines. Genotypic investigations were performed by conventional PCR to detect the target resistant genes. RESULTS Ceftriaxone, cefoxitin, clindamycin and imipenem were found to be the most resistant antimicrobials in E test method. Metronidazole has shown resistance in 7 strains in vitro while resistance nim genes were detected in 12 strains from 62 randomly selected isolates. Other resistance genes (cfiA, ermF and cepA) were expressed at 58%, 62.9% and 48.3% respectively, among these strains. CONCLUSION B fragilis group harbouring the resistant genes may not be fully expressed phenotypically. Hence, detection of these genes by PCR might be necessary for a pertinent conclusion.
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8
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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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9
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Graham C, Eshaghi A, Sarabia A, Zittermann S, Stapleton P, Kus JV, Patel SN. Identification and characterization of invasive multi-drug-resistant (MDR) Bacteroides genomospecies in Canada. Access Microbiol 2020; 2:acmi000111. [PMID: 32974576 PMCID: PMC7494187 DOI: 10.1099/acmi.0.000111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/11/2020] [Indexed: 11/27/2022] Open
Abstract
We identified and characterized a genome of the multi-drug-resistant Bacteroides genomospecies recovered from an invasive specimen from a hospitalized patient in Canada. The strain was resistant to penicillin, pipercillin-tazobactam, meropenem, clindaymycin and metronidazole. The strain harboured a plasmid containing the nimE gene, which has been shown to be associated with metronidazole resistance. The study highlights the importance of being vigilant in suspecting antimicrobial drug resistance when a patient is not improving on therapy.
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Affiliation(s)
- Christopher Graham
- Trillium Health Partners, Mississauga ON, Canada.,Department of Medicine, University of Toronto, Toronto ON, Canada
| | - Alireza Eshaghi
- Public Health Ontario Laboratory, Public Health Ontario, Toronto ON, Canada
| | | | - Sandra Zittermann
- Public Health Ontario Laboratory, Public Health Ontario, Toronto ON, Canada
| | - Patrick Stapleton
- Public Health Ontario Laboratory, Public Health Ontario, Toronto ON, Canada
| | - Julianne V Kus
- Public Health Ontario Laboratory, Public Health Ontario, Toronto ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto ON, Canada
| | - Samir N Patel
- Public Health Ontario Laboratory, Public Health Ontario, Toronto ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto ON, Canada
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Identification and Antimicrobial Susceptibility of Clinically Isolated Anaerobic Bacteria: A Retrospectively Study in a Jiangxi Tertiary-Care Hospital. Jundishapur J Microbiol 2019. [DOI: 10.5812/jjm.95800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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11
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Niestępski S, Harnisz M, Korzeniewska E, Aguilera-Arreola MG, Contreras-Rodríguez A, Filipkowska Z, Osińska A. The emergence of antimicrobial resistance in environmental strains of the Bacteroides fragilis group. ENVIRONMENT INTERNATIONAL 2019; 124:408-419. [PMID: 30682596 DOI: 10.1016/j.envint.2018.12.056] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/03/2018] [Accepted: 12/25/2018] [Indexed: 06/09/2023]
Abstract
Anaerobic bacteria of the genus Bacteroides are a large group of commensal microorganisms that colonize the human and animal digestive tract. The genus Bacteroides and the closely related genus Parabacteroides include the Bacteroides fragilis group (BFG) of potentially pathogenic bacteria which are frequently isolated from patients with anaerobic infections. The aim of this study was to assess the antimicrobial resistance of environmental strains of the Bacteroides fragilis group. Strains were isolated from human feces, hospital wastewater, influent (UWW) and effluent (TWW) wastewater from a wastewater treatment plant (WWTP), and from the feces of lab rats as a negative control to monitor the entire route of transmission of BFG strains from humans to the environment. The resistance of 123 environmental BFG strains to six antibiotic groups was analyzed with the use of culture-dependent methods. Additionally, the presence of 25 genes encoding antibiotic resistance was determined by PCR. The analyzed environmental BFG strains were highly resistant to the tested antibiotics. The percentage of resistant strains differed between the analyzed antibiotics and was determined at 97.56% for ciprofloxacin, 49.59% for erythromycin, 44.71% for ampicillin, 35.77% for tetracycline, 32.52% for amoxicillin/clavulanic acid, 26.83% for chloramphenicol, 26.01% for clindamycin, 11.38% for moxifloxacin, and 8.94% for metronidazole. The highest drug-resistance levels were observed in the strains isolated from UWW and TWW samples. The mechanisms of antibiotic-resistance were determined in phenotypically resistant strains of BFG. Research has demonstrated the widespread presence of genes encoding resistance to chloramphenicol (100% of all chloramphenicol-resistant strains), tetracyclines (97.78% of all tetracycline-resistant strains), macrolides, lincosamides and streptogramins (81.97% of all erythromycin-resistant strains). Genes encoding resistance to β-lactams and fluoroquinolones were less prevalent. None of the metronidazole-resistant strains harbored the gene encoding resistance to nitroimidazoles. BFG strains isolated from UWW and TWW samples were characterized by the highest diversity of antibiotic-resistance genes and were most often drug-resistant and multidrug-resistant. The present study examines the potential negative consequences of drug-resistant and multidrug-resistant BFG strains that are evacuated with treated wastewater into the environment. The transmission of these bacteria to surface water bodies can pose potential health threats for humans and animals; therefore, the quality of treated wastewater should be strictly monitored.
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Affiliation(s)
- Sebastian Niestępski
- Department of Environmental Microbiology, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-957 Olsztyn, Poland.
| | - Monika Harnisz
- Department of Environmental Microbiology, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-957 Olsztyn, Poland.
| | - Ewa Korzeniewska
- Department of Environmental Microbiology, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-957 Olsztyn, Poland.
| | - Ma Guadalupe Aguilera-Arreola
- Department of Microbiology, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City, Mexico
| | - Araceli Contreras-Rodríguez
- Department of Microbiology, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City, Mexico
| | - Zofia Filipkowska
- Department of Environmental Microbiology, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-957 Olsztyn, Poland.
| | - Adriana Osińska
- Department of Environmental Microbiology, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-957 Olsztyn, Poland.
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Dingsdag SA, Hunter N. Metronidazole: an update on metabolism, structure-cytotoxicity and resistance mechanisms. J Antimicrob Chemother 2019; 73:265-279. [PMID: 29077920 DOI: 10.1093/jac/dkx351] [Citation(s) in RCA: 168] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Metronidazole, a nitroimidazole, remains a front-line choice for treatment of infections related to inflammatory disorders of the gastrointestinal tract including colitis linked to Clostridium difficile. Despite >60 years of research, the metabolism of metronidazole and associated cytotoxicity is not definitively characterized. Nitroimidazoles are prodrugs that are reductively activated (the nitro group is reduced) under low oxygen tension, leading to imidazole fragmentation and cytotoxicity. It remains unclear if nitroimidazole reduction (activation) contributes to the cytotoxicity profile, or whether subsequent fragmentation of the imidazole ring and formed metabolites alone mediate cytotoxicity. A molecular mechanism underpinning high level (>256 mg/L) bacterial resistance to metronidazole also remains elusive. Considering the widespread use of metronidazole and other nitroimidazoles, this review was undertaken to emphasize the structure-cytotoxicity profile of the numerous metabolites of metronidazole in human and murine models and to examine conflicting reports regarding metabolite-DNA interactions. An alternative hypothesis, that DNA synthesis and repair of existing DNA is indirectly inhibited by metronidazole is proposed. Prokaryotic metabolism of metronidazole is detailed to discuss new resistance mechanisms. Additionally, the review contextualizes the history and current use of metronidazole, rates of metronidazole resistance including metronidazole MDR as well as the biosynthesis of azomycin, the natural precursor of metronidazole. Changes in the gastrointestinal microbiome and the host after metronidazole administration are also reviewed. Finally, novel nitroimidazoles and new antibiotic strategies are discussed.
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Affiliation(s)
- Simon A Dingsdag
- Institute of Dental Research and Westmead Centre for Oral Health, Westmead, NSW 2145, Australia.,Department of Life Sciences Faculty of Dentistry, The University of Sydney, NSW 2006, Australia.,The Westmead Institute for Medical Research, The University of Sydney, NSW 2145, Australia
| | - Neil Hunter
- Institute of Dental Research and Westmead Centre for Oral Health, Westmead, NSW 2145, Australia.,Department of Life Sciences Faculty of Dentistry, The University of Sydney, NSW 2006, Australia.,The Westmead Institute for Medical Research, The University of Sydney, NSW 2145, Australia
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13
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Metronidazole resistance and nim genes in anaerobes: A review. Anaerobe 2019; 55:40-53. [DOI: 10.1016/j.anaerobe.2018.10.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 10/01/2018] [Accepted: 10/05/2018] [Indexed: 01/06/2023]
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14
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Ghotaslou R, Bannazadeh Baghi H, Alizadeh N, Yekani M, Arbabi S, Memar MY. Mechanisms of Bacteroides fragilis resistance to metronidazole. INFECTION GENETICS AND EVOLUTION 2018; 64:156-163. [PMID: 29936037 DOI: 10.1016/j.meegid.2018.06.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/09/2018] [Accepted: 06/16/2018] [Indexed: 01/01/2023]
Abstract
Metronidazole-resistant Bacteroides fragilis (B. fragilis) have been reported worldwide. Several mechanisms contribute to B. fragilis resistance to metronidazole. In some cases, the mechanisms of metronidazole resistance are unknown. Understanding the mechanisms of resistance is important for therapy, the design of new alternative drugs, and control of resistant strains. In this study, a comprehensive review of the B. fragilis resistance mechanisms to metronidazole was prepared. The rate of metronidazole-resistant B. fragilis has been reported as ranging from 0.5% to 7.8% in many surveys. According to CLSI, isolates with MICs ≥32 μg/mL are considered to be metronidazole-resistant. In the majority of cases, metronidazole resistance in B. fragilis is coupled with the existence of nim genes. Metronidazole resistance could be induced in nim-negative strains by exposure to sub-MIC levels of metronidazole. There are multi-drug efflux pumps in B. fragilis which can pump out a variety of substrates such as metronidazole. The recA overexpression and deficiency of feoAB are other reported metronidazole resistance mechanisms in this bacterium.
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Affiliation(s)
- Reza Ghotaslou
- The Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Bannazadeh Baghi
- Department of Microbiology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Naser Alizadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mina Yekani
- Department of Microbiology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Shahram Arbabi
- The Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Yousef Memar
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
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Vrioni G, Tsiamis C, Oikonomidis G, Theodoridou K, Kapsimali V, Tsakris A. MALDI-TOF mass spectrometry technology for detecting biomarkers of antimicrobial resistance: current achievements and future perspectives. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:240. [PMID: 30069442 PMCID: PMC6046294 DOI: 10.21037/atm.2018.06.28] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The laboratory diagnosis of infections is based on pathogen identification and antimicrobial susceptibility determination. The gold standard of cultivation, isolation and susceptibility testing is a time-consuming procedure and in some cases this can be threatening for patients' outcome. In the current review the applications of mass spectrometry in pathogen identification and especially in detecting biomarkers of antimicrobial resistance are analyzed. MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry is a new technology that has revolutionized pathogen identification and has also proven to accelerate detection of antimicrobial resistance compared to the traditional antibiotic susceptibility tests (AST) as well as DNA amplification methodologies. The technology has incorporated up to know four different methodologies: (I) the detection of differences of mass spectra of susceptible and resistant isolates of a given microorganism using the classical strain typing methodology; (II) the analysis of bacterial induced hydrolysis of β-lactam antibiotics; (III) the detection of stable (non-radioactive) isotope-labeled amino acids; and (IV) the analysis of bacterial growth in the presence and absence of antibiotics using an internal standard. The implementation of MALDI-TOF methodologies has improved detection of resistance in aerobic, Gram-positive and Gram-negative bacteria, mycobacteria, anaerobic bacteria, fungi and viruses. The MALDI-TOF is an easy to use, rapid, reliable, economical, and environmentally friendly methodology. However, this technology needs further development of research protocols that will be validated for routine application.
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Affiliation(s)
- Georgia Vrioni
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Constantinos Tsiamis
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - George Oikonomidis
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Kalliopi Theodoridou
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Violeta Kapsimali
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Athanasios Tsakris
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Sárvári KP, Sóki J, Kristóf K, Juhász E, Miszti C, Melegh SZ, Latkóczy K, Urbán E. Molecular characterisation of multidrug-resistant Bacteroides isolates from Hungarian clinical samples. J Glob Antimicrob Resist 2018; 13:65-69. [DOI: 10.1016/j.jgar.2017.10.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/21/2017] [Accepted: 10/24/2017] [Indexed: 10/18/2022] Open
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Ghotaslou R, Yekani M, Memar MY. The role of efflux pumps in Bacteroides fragilis resistance to antibiotics. Microbiol Res 2018; 210:1-5. [DOI: 10.1016/j.micres.2018.02.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 02/10/2018] [Accepted: 02/25/2018] [Indexed: 02/07/2023]
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Tajkarimi M, Wexler HM. CRISPR-Cas Systems in Bacteroides fragilis, an Important Pathobiont in the Human Gut Microbiome. Front Microbiol 2017; 8:2234. [PMID: 29218031 PMCID: PMC5704556 DOI: 10.3389/fmicb.2017.02234] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 10/31/2017] [Indexed: 12/29/2022] Open
Abstract
Background: While CRISPR-Cas systems have been identified in bacteria from a wide variety of ecological niches, there are no studies to describe CRISPR-Cas elements in Bacteroides species, the most prevalent anaerobic bacteria in the lower intestinal tract. Microbes of the genus Bacteroides make up ~25% of the total gut microbiome. Bacteroides fragilis comprises only 2% of the total Bacteroides in the gut, yet causes of >70% of Bacteroides infections. The factors causing it to transition from benign resident of the gut microbiome to virulent pathogen are not well understood, but a combination of horizontal gene transfer (HGT) of virulence genes and differential transcription of endogenous genes are clearly involved. The CRISPR-Cas system is a multi-functional system described in prokaryotes that may be involved in control both of HGT and of gene regulation. Results: Clustered regularly interspaced short palindromic repeats (CRISPR) elements in all strains of B. fragilis (n = 109) with publically available genomes were identified. Three different CRISPR-Cas types, corresponding most closely to Type IB, Type IIIB, and Type IIC, were identified. Thirty-five strains had two CRISPR-Cas types, and three strains included all three CRISPR-Cas types in their respective genomes. The cas1 gene in the Type IIIB system encoded a reverse-transcriptase/Cas1 fusion protein rarely found in prokaryotes. We identified a short CRISPR (3 DR) with no associated cas genes present in most of the isolates; these CRISPRs were found immediately upstream of a hipA/hipB operon and we speculate that this element may be involved in regulation of this operon related to formation of persister cells during antimicrobial exposure. Also, blood isolates of B. fragilis did not have Type IIC CRISPR-Cas systems and had atypical Type IIIB CRISPR-Cas systems that were lacking adjacent cas genes. Conclusions: This is the first systematic report of CRISPR-Cas systems in a wide range of B. fragilis strains from a variety of sources. There are four apparent CRISPR-Cas systems in B. fragilis-three systems have adjacent cas genes. Understanding CRISPR/Cas function in B. fragilis will elucidate their role in gene expression, DNA repair and ability to survive exposure to antibiotics. Also, based on their unique CRISPR-Cas arrays, their phylogenetic clustering and their virulence potential, we are proposing that blood isolates of B. fragilis be viewed a separate subgroup.
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Affiliation(s)
- Mehrdad Tajkarimi
- Brentwood Biomedical Research Institute, Los Angeles, CA, United States
| | - Hannah M Wexler
- Brentwood Biomedical Research Institute, Los Angeles, CA, United States.,University of California, Los Angeles, Los Angeles, CA, United States.,GLAVA Health Care System, Los Angeles, CA, United States
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Gajdács M, Spengler G, Urbán E. Identification and Antimicrobial Susceptibility Testing of Anaerobic Bacteria: Rubik's Cube of Clinical Microbiology? Antibiotics (Basel) 2017; 6:E25. [PMID: 29112122 PMCID: PMC5745468 DOI: 10.3390/antibiotics6040025] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/30/2017] [Accepted: 11/03/2017] [Indexed: 12/26/2022] Open
Abstract
Anaerobic bacteria have pivotal roles in the microbiota of humans and they are significant infectious agents involved in many pathological processes, both in immunocompetent and immunocompromised individuals. Their isolation, cultivation and correct identification differs significantly from the workup of aerobic species, although the use of new technologies (e.g., matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, whole genome sequencing) changed anaerobic diagnostics dramatically. In the past, antimicrobial susceptibility of these microorganisms showed predictable patterns and empirical therapy could be safely administered but recently a steady and clear increase in the resistance for several important drugs (β-lactams, clindamycin) has been observed worldwide. For this reason, antimicrobial susceptibility testing of anaerobic isolates for surveillance purposes or otherwise is of paramount importance but the availability of these testing methods is usually limited. In this present review, our aim was to give an overview of the methods currently available for the identification (using phenotypic characteristics, biochemical testing, gas-liquid chromatography, MALDI-TOF MS and WGS) and antimicrobial susceptibility testing (agar dilution, broth microdilution, disk diffusion, gradient tests, automated systems, phenotypic and molecular resistance detection techniques) of anaerobes, when should these methods be used and what are the recent developments in resistance patterns of anaerobic bacteria.
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Affiliation(s)
- Márió Gajdács
- Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary.
| | - Gabriella Spengler
- Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, 6720 Szeged, Hungary.
| | - Edit Urbán
- Institute of Clinical Microbiology, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary.
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Ho PL, Yau CY, Ho LY, Lai ELY, Liu MCJ, Tse CWS, Chow KH. Antimicrobial susceptibility of Bacteroides fragilis group organisms in Hong Kong by the tentative EUCAST disc diffusion method. Anaerobe 2017; 47:51-56. [PMID: 28414107 DOI: 10.1016/j.anaerobe.2017.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 04/06/2017] [Accepted: 04/13/2017] [Indexed: 12/29/2022]
Abstract
This study used a recently developed EUCAST disc diffusion method to measure the susceptibility of 741 B. fragilis group isolates to six antibiotics. Isolates nonsusceptible to imipenem and metronidazole by the disc method were further investigated by E-test. Species identification was obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), PCR assays and 16S rRNA sequencing. The most common species were B. fragilis (n = 424, including 81 division II and 343 division I isolates), B. thetaiotaomicron (n = 111), B. ovatus (n = 53) and B. vulgatus (n = 46). Overall, metronidazole following by imipenem and amoxicillin-clavulanate are the most active agents with over 90% of all the isolates being susceptible at the tentative disc breakpoints. Susceptibility rates for moxifloxacin (69.5%), piperacillin-tazobactam (58.2%) and clindamycin (37.2%) were much lower. Metronidazole is the only agent active against >90% of B. fragilis, non-fragilis Bacteroides and Parabacteroides isolates. With the exception of B. fragilis division II, imipenem was active against 88.0%-98.3% of isolates of the other species. Susceptibility rates for clindamycin (14.4%-54.3%) and moxifloxacin (33.3%-80.6%) were low across all species and many isolates had no inhibition zone around the discs. E-test testing confirmed 8.2% (61/741) and 1.6% (12/741) isolates as nonsusceptible to imipenem and metronidazole, respectively with B. fragilis and B. thetaoiotaomicron accounting for a large share of the observed resistance to both agents. Two imipenem-resistant and one metronidazole-resistant B. dorei were misidentified as B. vulgatus by MALDI-TOF MS. These data highlights the importance anaerobic susceptibility testing in clinical laboratories to guide therapy.
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Affiliation(s)
- Pak-Leung Ho
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Queen Mary Hospital, Hong Kong Special Administrative Region.
| | - Chong-Yee Yau
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Queen Mary Hospital, Hong Kong Special Administrative Region
| | - Lok-Yan Ho
- Department of Clinical Pathology, Kwong Wah Hospital, Hospital Authority, Hong Kong Special Administrative Region
| | - Eileen Ling-Yi Lai
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Queen Mary Hospital, Hong Kong Special Administrative Region
| | - Melissa Chun-Jiao Liu
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Queen Mary Hospital, Hong Kong Special Administrative Region
| | - Cindy Wing-Sze Tse
- Department of Clinical Pathology, Kwong Wah Hospital, Hospital Authority, Hong Kong Special Administrative Region
| | - Kin-Hung Chow
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Queen Mary Hospital, Hong Kong Special Administrative Region
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Abstract
Alteration in the host microbiome at skin and mucosal surfaces plays a role in the function of the immune system, and may predispose immunocompromised patients to infection. Because obligate anaerobes are the predominant type of bacteria present in humans at skin and mucosal surfaces, immunocompromised patients are at increased risk for serious invasive infection due to anaerobes. Laboratory approaches to the diagnosis of anaerobe infections that occur due to pyogenic, polymicrobial, or toxin-producing organisms are described. The clinical interpretation and limitations of anaerobe recovery from specimens, anaerobe-identification procedures, and antibiotic-susceptibility testing are outlined. Bacteriotherapy following analysis of disruption of the host microbiome has been effective for treatment of refractory or recurrent Clostridium difficile infection, and may become feasible for other conditions in the future.
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Affiliation(s)
- Deirdre L Church
- Departments of Pathology & Laboratory Medicine and Medicine, University of Calgary, and Division of Microbiology, Calgary Laboratory Services, Calgary, Alberta, Canada T2N 1N4
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Multidrug-Resistant Bacteroides fragilis Bacteremia in a US Resident: An Emerging Challenge. Case Rep Infect Dis 2016; 2016:3607125. [PMID: 27418986 PMCID: PMC4935919 DOI: 10.1155/2016/3607125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/30/2016] [Indexed: 11/24/2022] Open
Abstract
We describe a case of Bacteroides fragilis bacteremia associated with paraspinal and psoas abscesses in the United States. Resistance to b-lactam/b-lactamase inhibitors, carbapenems, and metronidazole was encountered despite having a recent travel history to India as the only possible risk factor for multidrug resistance. Microbiological cure was achieved with linezolid, moxifloxacin, and cefoxitin.
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Fernández-Murga ML, Sanz Y. Safety Assessment of Bacteroides uniformis CECT 7771 Isolated from Stools of Healthy Breast-Fed Infants. PLoS One 2016; 11:e0145503. [PMID: 26784747 PMCID: PMC4718450 DOI: 10.1371/journal.pone.0145503] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 12/05/2015] [Indexed: 12/16/2022] Open
Abstract
Background Bacteroides uniformis CECT 7771 is a potential probiotic strain, originally isolated from the stools of healthy breast-feed infants. The strain showed pre-clinical efficacy in a mouse obesity model. The objective of this study was to evaluate its potential toxicity and translocation ability after acute oral administration to mice. Methods and Findings A safety study was conducted in immunocompetent and immunosuppressed C57BL-6 mice. Both mouse groups (n = 10 per group) were fed orally 2 x 109 colony forming units (cfu)/day of B. uniformis CECT 7771 or placebo by gavage for 6 days. Throughout this time, feed and water intake and body weight were monitored. Afterwards, mice were sacrificed and biological samples were collected to analyze blood and urine biochemistry, inflammatory and immune markers; gut mucosal histology and bacterial translocation to peripheral tissues. The results demonstrated that acute ingestion of this Bacteroides strain had no adverse effects on the animals’ general health status or food intake, nor did it affect biochemical indicators of liver, kidney and pancreatic function or gut mucosal histology. Findings also demonstrated that administration did not lead to bacterial translocation to blood, liver or mesenteric lymph nodes. B. uniformis CECT 7771 also downregulated gene and protein expression (iNOS and PPAR-γ) and inflammatory cytokines induced by immunosuppression. Conclusions The findings indicate that the acute oral consumption of B. uniformis CECT 7771 does not raise safety concerns in mice. Further studies in humans should be conducted.
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Affiliation(s)
- M. Leonor Fernández-Murga
- Microbial Ecology, Nutrition & Health Research Unit, Institute of Agrochemistry and Food Technology, National Research Council (IATA-CSIC), Valencia, Spain
| | - Yolanda Sanz
- Microbial Ecology, Nutrition & Health Research Unit, Institute of Agrochemistry and Food Technology, National Research Council (IATA-CSIC), Valencia, Spain
- * E-mail:
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