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Buhl MEJ, Sunnerhagen T, Join-Lambert O, Morris T, Jeverica S, Assous MV, Toprak NU, Alcalá-Hernandez L, Lienhard R, Veloo ACM, Cruz H, Sóki J, Novak A, Mazzariol A, Wybo I, Dumont Y, Justesen US. Antimicrobial resistance surveillance of Bacteroides fragilis isolated from blood cultures, Europe, 2022 (ReSuBacfrag). Int J Antimicrob Agents 2024; 64:107241. [PMID: 38942247 DOI: 10.1016/j.ijantimicag.2024.107241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/23/2024] [Accepted: 06/07/2024] [Indexed: 06/30/2024]
Abstract
OBJECTIVES Bacteroides fragilis is the most frequent cause of anaerobic bacteraemia. Although recent data suggest a rise in antimicrobial resistance (AMR) of this and other anaerobic bacteria, surveillance remains limited due to a lack of both data availability and comparability. However, a newly introduced standardised method for antimicrobial susceptibility testing (AST) of anaerobic bacteria has made larger scale surveillance possible for the first time. The aim of this study was to investigate phenotypic AMR of Bacteroides fragilis isolates from bacteraemia across Europe in 2022. METHODS In a multicentre approach, clinical microbiology laboratories in Europe were invited to contribute results of AST for Bacteroides fragilis blood culture isolates (including only the first isolate per patient and year). AST of a selection of four antibiotics was performed locally by participating laboratories in a prospective or retrospective manner, using the new EUCAST disc diffusion method on fastidious anaerobe agar (FAA-HB). RESULTS A total of 16 European countries reported antimicrobial susceptibilities in 449 unique isolates of Bacteroides fragilis from blood cultures in 2022. Clindamycin demonstrated the highest resistance rates (20.9%, range 0 - 63.6%), followed by piperacillin-tazobactam (11.1%, 0-54.5%), meropenem (13.4%, 0-45.5%), and metronidazole (1.8%, 0-20.0%), all with wide variation between countries. CONCLUSION Considering that the mean resistance rates across Europe were higher than expected for three of the four anti-anaerobic antibiotics under surveillance, both local AST of clinically relevant isolates of Bacteroides fragilis and continued surveillance on an international level is warranted.
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Affiliation(s)
- Michael E J Buhl
- Institute of Clinical Microbiology, Infectious Diseases and Infection Control, Klinikum Nürnberg, Paracelsus Medical University, Nürnberg, Germany.
| | - Torgny Sunnerhagen
- Clinical microbiology and infection control, Region Skåne Office for Medical Services, Lund, Sweden; Infection medicine, Department for clinical sciences Lund, Medical Faculty, Lund University, Lund, Sweden
| | | | - Trefor Morris
- UK Anaerobe Reference Unit, University Hospital of Wales, Cardiff, United Kingdom
| | - Samo Jeverica
- National Laboratory for Health, Environment and Food, Novo mesto, Slovenia
| | - Marc V Assous
- Laboratory of Clinical Microbiology and Immunology, Shaare Zedek Medical Center, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nurver U Toprak
- Department of Clinical Microbiology, Marmara University Hospital, Istanbul, Turkey
| | - Luis Alcalá-Hernandez
- Department of Clinical Microbiology, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | | | - Alida C M Veloo
- University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, University of Groningen, Groningen, the Netherlands
| | - Hugo Cruz
- Microbiology Department, Centro Hospitalar Universitário de Santo António, EPE (CHUdSA), Porto, Portugal
| | - József Sóki
- Institute of Medical Microbiology, Albert Szent-Györgyi Health Centre, University of Szeged, Szeged, Hungary
| | - Anita Novak
- Department of Clinical Microbiology, University Hospital of Split, Split, Croatia
| | - Annarita Mazzariol
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy; UOC Microbiology and Virology, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Ingrid Wybo
- Department of Microbiology and Infection Control, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | | | - Ulrik S Justesen
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
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Ayyal Salman H, Yaakop AS, Al-Rimawi F, Ahmad Makhtar AM, Mousa M, Semreen MH, Alharbi NS. Ephedra alte extracts' GC-MS profiles and antimicrobial activity against multidrug-resistant pathogens (MRSA). Heliyon 2024; 10:e27051. [PMID: 38444505 PMCID: PMC10912435 DOI: 10.1016/j.heliyon.2024.e27051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 02/08/2024] [Accepted: 02/22/2024] [Indexed: 03/07/2024] Open
Abstract
The extracts of E. alte offer promising potential as renewable resources for various chemical derivative products aimed at addressing antibiotic resistance. These extracts exhibited significant activity against methicillin-resistant Staphylococcus aureus (MRSA), a strain known for its resistance to multiple antibiotics. The extracts were found to be effective against several common antibiotics, including Imipenem, Ampicillin, Penicillin G, Oxacillin, and Amoxicillin-clavulanate. GC-MS analysis revealed that the phytoconstituents of E. alte extracts, obtained using both methanol and ethyl acetate, consist of a diverse range of 83 and 160 phytocompounds, respectively. These organic compounds serve as important biochemical precursors for the synthesis of vitamins E and K1, and exhibit antioxidant, antimicrobial, and anti-inflammatory properties in both plants and microorganisms. Notable compounds identified include fatty acids (such as palmitic acid, dodecanoic acid, sebacic acid, pentadecanoic acid, myristic acid, stearic acid, behenic acid, and linoelaidic acid), phytosterols (Campesterol, β-sitosterol, Stigmast-5-ene), sugars (D-fructose, Fructofuranans), terpenoids (Phytol, citronellol), and phenolic acids (Protocatechoic acid, shikimic acid). The antimicrobial activity of all E. alte extracts was found to be superior to that of mupirocin and ciprofloxacin, as observed in susceptibility testing against MRSA ATCC 43300 and other pathogenic bacteria and fungi. It is likely that the combined action of the antimicrobial components within the E. alte extract bypasses the mechanisms employed by MRSA to protect itself from antibiotics. Further experiments are needed to investigate the individual effects of each pure compound and their potential synergistic interactions, which may enhance their overall performance.
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Affiliation(s)
- Haya Ayyal Salman
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Amira Suriaty Yaakop
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Fuad Al-Rimawi
- Chemistry Department, Faculty of Science and Technology, Al-Quds University, P.O. Box 2002, Jerusalem, Palestine
| | - Ana Masara Ahmad Makhtar
- Green Biopolymer Coating and Packaging Centre, School of Industrial Technology, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Muath Mousa
- BIOSCOPE Research Group, LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516, Caparica, Portugal
| | - Mohammad H. Semreen
- Research Institute for Medical and Health Sciences (RIHMS), University of Sharjah, Sharjah, United Arab Emirates
| | - Naiyf S. Alharbi
- Department of Botany and Microbiology, College of Science, King Saud University, P. O. Box 2455, Riyadh, 11451, Saudi Arabia
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Rivera A, Viñado B, Benito N, Docobo-Pérez F, Fernández-Cuenca F, Fernández-Domínguez J, Guinea J, López-Navas A, Moreno MÁ, Larrosa MN, Oliver A, Navarro F. Recommendations of the Spanish Antibiogram Committee (COESANT) for in vitro susceptibility testing of antimicrobial agents by disk diffusion. ENFERMEDADES INFECCIOSAS Y MICROBIOLOGIA CLINICA (ENGLISH ED.) 2023; 41:571-576. [PMID: 36610835 DOI: 10.1016/j.eimce.2022.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 04/27/2022] [Indexed: 01/07/2023]
Abstract
Disk diffusion is a well standardized method that provides reliable categorical results to guide antimicrobial therapy in numerous types of infections. Based on the guidelines of the European Committee on Antimicrobial Susceptibility Testing (EUCAST), which are widely implemented in Spain, the Spanish Antibiogram Committee (COESANT) has drawn up recommendations for antimicrobial selection by the disk diffusion technique, including selective reporting and its use for the detection of resistance mechanisms. Factors affecting disk diffusion results, along with advantages and shortcomings of the method, are also discussed.
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Affiliation(s)
- Alba Rivera
- Servicio de Microbiología, Hospital de la Santa Creu i Sant Pau, Departamento de Genética y de Microbiología de la Universitat Autònoma de Barcelona, Institut d'Investigació Biomèdica de Sant Pau (IIB Sant Pau), Barcelona, Spain
| | - Belén Viñado
- Servicio de Microbiología, Hospital Universitario Vall d'Hebron, Universitat Autònoma de Barcelona, Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain
| | - Natividad Benito
- Unidad de Enfermedades Infecciosas, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut d'Investigació Biomèdica de Sant Pau (IIB Sant Pau), Barcelona, Spain
| | - Fernando Docobo-Pérez
- Departamento de Microbiología, Universidad de Sevilla, Sevilla, Spain; Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain; Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Felipe Fernández-Cuenca
- Unidad Clínica de Enfermedades Infecciosas y Microbiología, Hospital Universitario Virgen Macarena, Sevilla, Spain; Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Javier Fernández-Domínguez
- Servicio de Microbiología, Hospital Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Guinea
- CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain; Servicio de Microbiología y Enfermedades Infecciosas, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Antonio López-Navas
- Agencia Española de Medicamentos y Productos Sanitarios (AEMPS), Madrid, Spain
| | - Miguel Ángel Moreno
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
| | - María Nieves Larrosa
- Servicio de Microbiología, Hospital Universitario Vall d'Hebron, Universitat Autònoma de Barcelona, Vall d'Hebron Institut de Recerca (VHIR), Barcelona, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain; Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Antonio Oliver
- Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain; Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain; Servicio de Microbiología, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain
| | - Ferran Navarro
- Servicio de Microbiología, Hospital de la Santa Creu i Sant Pau, Departamento de Genética y de Microbiología de la Universitat Autònoma de Barcelona, Institut d'Investigació Biomèdica de Sant Pau (IIB Sant Pau), Barcelona, Spain.
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Fang H, Li X, Yan MK, Tong MK, Chow KH, Cheng VCC, Ho PL. Antimicrobial susceptibility of Bacteroides fragilis group organisms in Hong Kong, 2020-2021. Anaerobe 2023; 82:102756. [PMID: 37429411 DOI: 10.1016/j.anaerobe.2023.102756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/01/2023] [Accepted: 06/19/2023] [Indexed: 07/12/2023]
Abstract
OBJECTIVES This retrospective study analyzed the susceptibility levels of Bacteroides fragilis group (BFG) in a hospital-based laboratory where disk diffusion test (DDT) was routinely performed. Isolates non-susceptible to imipenem and metronidazole by DDT were further investigated using a gradient method. METHODS The DDT and MIC susceptibility data of clindamycin, metronidazole, moxifloxacin and imipenem obtained on Brucella blood agar for 1264 non-duplicated isolates during 2020-2021 were analyzed. Species identification was obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry and 16S rRNA sequencing. Interpretative agreement of DDT results using the 2015 EUCAST tentative and 2021 CA-SFM breakpoints was compared against MIC as the reference. RESULTS The dataset included 604 B. fragilis (483 division I, 121 division II isolates), 415 non-fragilis Bacteroides, 177 Phocaeicola and 68 Parabacteroides. Susceptibility rates for clindamycin (22.1-62.1%) and moxifloxacin (59.9-80.9%) were low and many had no inhibition zones. At the EUCAST and CA-SFM breakpoints, 83.0 and 89.4% were imipenem-susceptible, and 89.6% and 97.4 were metronidazole-susceptible. MIC testing confirmed 11.4% and 2.8% isolates as imipenem-non-susceptible and metronidazole-resistant, respectively. Significant numbers of false-susceptibility and/or false-resistance results were observed at the CA-SFM breakpoint but not the EUCAST breakpoint. Higher rates of imipenem and/or metronidazole resistance were detected in B. fragilis division II, B. caccae, B. ovatus, B. salyersiae, B. stercoris and Parabacteroides. Co-resistance to imipenem and metronidazole was detected in 3 B. fragilis division II isolates. CONCLUSIONS The data demonstrated emerging BFG resistance to several important anti-anaerobic antibiotics and highlights the importance of anaerobic susceptibility testing in clinical laboratories to guide therapy.
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Affiliation(s)
- Hanshu Fang
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Xin Li
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region of China; Department of Microbiology, Queen Mary Hospital, Hospital Authority, Hong Kong Special Administrative Region of China
| | - Mei-Kum Yan
- Department of Microbiology, Queen Mary Hospital, Hospital Authority, Hong Kong Special Administrative Region of China
| | - Man-Ki Tong
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Kin-Hung Chow
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Vincent Chi-Chung Cheng
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region of China; Department of Microbiology, Queen Mary Hospital, Hospital Authority, Hong Kong Special Administrative Region of China
| | - Pak-Leung Ho
- Department of Microbiology and Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong Special Administrative Region of China; Department of Microbiology, Queen Mary Hospital, Hospital Authority, Hong Kong Special Administrative Region of China.
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Stubhaug TT, Giske CG, Justesen US, Kahlmeter G, Matuschek E, Sundsfjord A, Skaare D. Antimicrobial susceptibility testing of Bacteroides species by disk diffusion: The NordicAST Bacteroides study. Anaerobe 2023:102743. [PMID: 37253399 DOI: 10.1016/j.anaerobe.2023.102743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/16/2023] [Accepted: 05/22/2023] [Indexed: 06/01/2023]
Abstract
OBJECTIVES - Antimicrobial susceptibility testing (AST) of anaerobic bacteria has until recently been done by MIC methods. We have carried out a multi-centre evaluation of the newly validated EUCAST disk diffusion method for AST of Bacteroides spp. METHODS - A panel of 30 Bacteroides strains was assembled based on reference agar dilution MICs, resistance gene detection and quantification of cfiA carbapenemase gene expression. Nordic clinical microbiology laboratories (n = 45) performed disk diffusion on Fastidious Anaerobe Agar with 5% mechanically defibrinated horse blood (FAA-HB) for piperacillin-tazobactam, meropenem and metronidazole. RESULTS - A total of 43/45 (95.6%) laboratories carried out disk diffusion per protocol. Intraclass correlation coefficients were 0.87 (0.80-0.93) for piperacillin-tazobactam, 0.95 (0.91-0.97) for meropenem and 0.89 (0.83-0.94) for metronidazole. For metronidazole, one media lot yielded smaller zones and higher variability than another. Piperacillin-tazobactam and meropenem zone diameters correlated negatively with cfiA expression. A meropenem zone diameter of <28 mm in B. fragilis indicated presence of cfiA. Piperacillin-tazobactam had the most false susceptible results. Categorical errors for this antimicrobial were particularly prevalent in cfiA-positive strains, and piperacillin-tazobactam had the highest number of comments describing zone reading difficulties. CONCLUSIONS - Inter-laboratory agreement by disk diffusion was good or very good. The main challenges were media-related variability for metronidazole and categorical disagreement with the reference method for piperacillin-tazobactam in some cfiA-positive strains. An area of technical uncertainty specific for such strains may be warranted.
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Affiliation(s)
- Tore Taksdal Stubhaug
- Vestfold Hospital Trust, Department of Microbiology, Tønsberg, Norway; University of Oslo, Institute of Clinical Medicine, Oslo, Norway.
| | - Christian G Giske
- Karolinska University Hospital, Department of Clinical Microbiology, Stockholm, Sweden; Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Ulrik S Justesen
- Odense University Hospital, Department of Clinical Microbiology, Odense, Denmark
| | | | | | - Arnfinn Sundsfjord
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance (K-res), University Hospital of North Norway, Tromsø, Norway; UiT the Arctic University of Norway, Department of Medical Biology, Tromsø, Norway
| | - Dagfinn Skaare
- Vestfold Hospital Trust, Department of Microbiology, Tønsberg, Norway
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Justesen US, Åhman J, Matuschek E, Kahlmeter G. Assessing the quality of the anaerobic environment - a method developed to support EUCAST disk diffusion of anaerobic bacteria. Eur J Clin Microbiol Infect Dis 2023:10.1007/s10096-023-04622-9. [PMID: 37171541 DOI: 10.1007/s10096-023-04622-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/08/2023] [Indexed: 05/13/2023]
Abstract
The purpose of this study is to establish a method for assessing the anaerobic environment for EUCAST disk diffusion antimicrobial susceptibility testing (AST) of anaerobic bacteria on fastidious anaerobe agar with 5% mechanically defibrinated horse blood (FAA-HB). The method utilizes the association between a decrease in the metronidazole disk zone diameter and increasing oxygen levels with an aerotolerant Clostridium perfringens strain DSM 25589 (CCUG 75076 and NCTC 14679). The C. perfringens strain was tested on FAA-HB with a McFarland 1 inoculum and a metronidazole 5 μg disk. FAA-HB was incubated for 16-20 h at 35-37°C. The association between oxygen levels (0, 0.16, 1, 2, and 4% oxygen) and the metronidazole zone diameter was determined. Reproducibility at 0% oxygen was investigated as part of a European multi-centre study of disk diffusion of anaerobic bacteria. The median zone diameters (n=12) at each oxygen level were 29 mm (0%), 21 mm (0.16%), 16 mm (1%), 15 mm (2%), and 15 mm (4%). The metronidazole zone diameters at 0% oxygen from the multi-centre reproducibility-study had a median of 29 mm and a 95%-percentile range of 25-33 mm (n=236). Only one reading was below 25 mm. Based on our results, a zone diameter of ≥25 mm using a metronidazole 5 μg disk and the C. perfringens strain, tested with EUCAST recommendations, can be used to indicate that the anaerobic environment is of sufficient quality for culture and disk diffusion AST. EUCAST has included the method as part of the quality control for AST of anaerobic bacteria.
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Affiliation(s)
- Ulrik Stenz Justesen
- Department of Clinical Microbiology, Odense University Hospital, J. B. Winsløwsvej 21, 2, 5000, Odense, Denmark.
| | - Jenny Åhman
- EUCAST Development Laboratory, Växjö, Sweden
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Matuschek E, Copsey-Mawer S, Petersson S, Åhman J, Morris TE, Kahlmeter G. The European committee on antimicrobial susceptibility testing disc diffusion susceptibility testing method for frequently isolated anaerobic bacteria. Clin Microbiol Infect 2023:S1198-743X(23)00052-6. [PMID: 36746258 DOI: 10.1016/j.cmi.2023.01.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 01/20/2023] [Accepted: 01/30/2023] [Indexed: 02/08/2023]
Abstract
OBJECTIVES Antimicrobial resistance in anaerobic bacteria is increasing and there is a link between inappropriate antimicrobial therapy and poor clinical outcome in the treatment of infections caused by anaerobic bacteria. Accurate and timely antimicrobial susceptibility testing of anaerobic bacteria is therefore of critical importance. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) has recently described a disc diffusion susceptibility testing method for anaerobic bacteria using fastidious anaerobe agar (FAA) supplemented with 5% defibrinated horse blood (HB). This method was previously validated for Bacteroides spp. only. The aim of this study was to determine the suitability of FAA-HB for disc diffusion and also for frequently isolated anaerobic bacteria. METHODS Clinical isolates, including 54 Bacteroides/Phocaeicola/Parabacteroides spp., 49 Prevotella spp., 51 Fusobacterium necrophorum, 58 Clostridium perfringens, and 54 Cutibacterium acnes were evaluated against six antimicrobial agents. MICs were determined by agar dilution following Clinical and Laboratory Standards Institute methodology, modified to use FAA-HB as recommended by EUCAST, instead of supplemented Brucella agar, and disc diffusion was performed on FAA-HB following EUCAST methodology. RESULTS Results for quality control strains were reproducible, with 99.3% of zones within range. Disc diffusion by EUCAST methodology was able to distinguish between susceptible and resistant isolates of anaerobic bacteria for benzylpenicillin, piperacillin-tazobactam, meropenem, clindamycin, and metronidazole (98.7% correct categorization). No isolates resistant to vancomycin were tested, but zone diameters correctly categorized the susceptible isolates, and there was a logical relationship between MICs and inhibition zones. DISCUSSION The recently published EUCAST method for disc diffusion for anaerobic bacteria based on FAA-HB is a reproducible and accurate method for susceptibility testing of frequently isolated anaerobic bacteria.
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Affiliation(s)
- Erika Matuschek
- The European Committee on Antimicrobial Susceptibility Testing Development Laboratory, Växjö, Sweden.
| | | | | | - Jenny Åhman
- The European Committee on Antimicrobial Susceptibility Testing Development Laboratory, Växjö, Sweden
| | | | - Gunnar Kahlmeter
- The European Committee on Antimicrobial Susceptibility Testing Development Laboratory, Växjö, Sweden
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Time for Some Group Therapy: Update on Identification, Antimicrobial Resistance, Taxonomy, and Clinical Significance of the Bacteroides fragilis Group. J Clin Microbiol 2022; 60:e0236120. [PMID: 35700139 DOI: 10.1128/jcm.02361-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteroides fragilis group (BFG) species are common members of the human microbiota that provide several benefits to healthy hosts, yet BFG are also the most common anaerobes isolated from human infections, including intra-abdominal infections, abscesses, and bloodstream infection. Compared to many other anaerobes associated with disease, members of the BFG are more likely to be resistant to commonly used antimicrobials, including penicillin (>90% resistant), carbapenems (2 to 20% resistant), and metronidazole (0.2 to 4% resistant). As a result, infection with BFG bacteria can be associated with poor clinical outcomes. Here, we discuss the role of BFG in human health and disease, proposed taxonomic reclassifications within the BFG, and updates in methods for species-level identification. The increasing availability of whole-genome sequencing (WGS) supports recent proposals that the BFG now span two families (Bacteroidaceae and "Tannerellaceae") and multiple genera (Bacteroides, Parabacteroides, and Phocaeicola) within the phylum Bacteroidota. While members of the BFG are often reported to "group" rather than "species" level in many clinical settings, new reports of species-specific trends in antimicrobial resistance profiles and improved resolution of identification tools support routine species-level reporting in clinical practice. Empirical therapy may not be adequate for treatment of serious infections with BFG, warranting susceptibility testing for serious infections. We summarize methods for antimicrobial susceptibility testing and resistance prediction for BFG, including broth microdilution, agar dilution, WGS, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). We examine global trends in BFG antimicrobial resistance and review genomics of BFG, revealing insights into rapid activation and dissemination of numerous antimicrobial resistance mechanisms.
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Rivera A, Viñado B, Benito N, Docobo-Pérez F, Fernández-Cuenca F, Fernández-Domínguez J, Guinea J, López-Navas A, Moreno MÁ, Larrosa MN, Oliver A, Navarro F. Recommendations of the Spanish Antibiogram Committee (COESANT) for in vitro susceptibility testing of antimicrobial agents by disk diffusion. Enferm Infecc Microbiol Clin 2022. [DOI: 10.1016/j.eimc.2022.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Antimicrobial susceptibility testing of anaerobic bacteria: In routine and research. Anaerobe 2022; 75:102559. [DOI: 10.1016/j.anaerobe.2022.102559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 03/22/2022] [Accepted: 04/07/2022] [Indexed: 11/21/2022]
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Dubreuil L, Veloo AC, Sóki J. Correlation between antibiotic resistance and clinical outcome of anaerobic infections; mini-review. Anaerobe 2021; 72:102463. [PMID: 34597797 DOI: 10.1016/j.anaerobe.2021.102463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 10/20/2022]
Abstract
In anaerobic infections, the relationship between clinical failure and antibiotic resistance is difficult to demonstrate, especially in mixed anaerobic-aerobic infections. Single isolates of anaerobes in cases of bacteraemia revealed that treatment failures were due to inappropriate therapy. We review here cases, where the empiric treatment was unsuccessful due to resistance of anaerobic bacteria to the administered agents and where the change of the antibiotic allowed the patients to be cured. Many therapeutic failures could be linked to the lack of timely detection of resistance, including heteroresistance of the anaerobes. Disk diffusion or Etest methodology may be suitable, at least for rapidly growing anaerobes, to detect both resistance and heteroresistance to antibiotics widely used for empirical therapy.
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Affiliation(s)
| | - Alida C Veloo
- Department of Medical Microbiology, University Medical Center Groningen, University of Groningen, the Netherlands
| | - József Sóki
- Institute of Medical Microbiology, University of Szeged, Hungary.
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Sood A, Angrup A, Ray P, Bala K. Comparative evaluation of agar dilution and broth microdilution by commercial and in-house plates for Bacteroides fragilis group: An economical and expeditious approach for resource-limited settings. Anaerobe 2021; 71:102443. [PMID: 34492368 DOI: 10.1016/j.anaerobe.2021.102443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/10/2021] [Accepted: 09/03/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To compare the performance of agar dilution and broth microdilution by commercial and in-house prepared plates for the Bacteroides fragilis group. The cost analysis was performed to demonstrate that in-house prepared BMD plates were a suitable alternative to agar dilution given the high cost and low feasibility of incorporating commercial BMD plates in routine, particularly in the tertiary care institutes of many low- and middle-income countries. METHODS Thirty B. fragilis group isolates were tested against six antibiotics, frequently used as empirical therapy for anaerobic infections including metronidazole, clindamycin, imipenem, piperacillin-tazobactam, cefoxitin, and chloramphenicol. The running consumable expenditure for all methodologies was calculated. RESULTS The results demonstrated essential and categorical agreement of >90% for all antibiotics except cefoxitin, which showed <90% categorical agreement. No major or very major errors were observed. We observed a high agreement and strong concordance for MIC values between both methods and inter-rate reliability of >0.9 by Cohen's kappa analysis, indicating almost perfect agreement between both methods using either of the plates. In contrast to agar dilution, a 20.5 fold cost reduction was seen in BMD using in-house plates and a 5.8 fold reduction using commercial plates to test a single isolate. However, when testing 30 isolates concurrently the cost significantly increased for commercial BMD plates by 8.4 folds, and only 1.03 fold cost reduction was seen with in-house BMD plates. CONCLUSION BMD gives comparable results to agar dilution and can be considered a method of choice to test a small number of samples. The technique is an economical option when plates are standardized in-house and could be employed for susceptibility testing of the B. fragilis group.
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Affiliation(s)
- Anshul Sood
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
| | - Archana Angrup
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
| | - Pallab Ray
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
| | - Kiran Bala
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
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EUCAST invite comments on new methods for antimicrobial susceptibility testing of anaerobic bacteria. Anaerobe 2021; 70:102417. [PMID: 34314866 DOI: 10.1016/j.anaerobe.2021.102417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/21/2022]
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