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Brook I. Overview of Anaerobic infections in children and their treatment. J Infect Chemother 2024:S1341-321X(24)00192-2. [PMID: 39029623 DOI: 10.1016/j.jiac.2024.07.014] [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: 03/31/2024] [Revised: 05/30/2024] [Accepted: 07/14/2024] [Indexed: 07/21/2024]
Abstract
Anaerobic bacteria can cause many infections in children. Because they predominant in the normal human skin and mucous membranes bacterial flora, they are often associated with bacterial infections that originate from these sites. They are difficult to isolate from infectious sites, and are frequently missed. Anaerobic infections can occur in all body sites, including the central nervous system, oral cavity, head and neck, chest, abdomen, pelvis, skin, and soft tissues. Anaerobes colonize the newborn after birth and have been isolated in several types of neonatal infections. These include cellulitis of the site of fetal monitoring, neonatal aspiration pneumonia, bacteremia, conjunctivitis, omphalitis, and infant botulism. Management of anaerobic infection is challenging because of the the slow growth of these bacteria, by their polymicrobial nature and by the growing antimicrobial resistance of anaerobic. Antimicrobial therapy may be the only treatment required, and may also be an adjunct to a surgical approach. Polymicrobial aerobic-anaerobic infection generally requires delivering antimicrobial therapy effective against all pathogens. The antibiotics with the greatest activity against anaerobes include carbapenems, beta-lactam/beta-lactamase inhibitor combinations, metronidazole, and chloramphenicol. Antimicrobial resistance is growing among anaerobic bacteria. The major increased in resistance have been reported with clindamycin, cephamycins, and moxifloxacin against Bacteroides fragilis group and related strains. Resistance patterns vary between different geographic areas and medical facilities.
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Affiliation(s)
- Itzhak Brook
- Georgetown University School of Medicine, Washington DC.
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2
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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 2024:107241. [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
BACKGROUND 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. AIM 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, Nuremberg, 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, 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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3
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Villa F, Marchandin H, Lavigne JP, Schuldiner S, Cellier N, Sotto A, Loubet P. Anaerobes in diabetic foot infections: pathophysiology, epidemiology, virulence, and management. Clin Microbiol Rev 2024:e0014323. [PMID: 38819166 DOI: 10.1128/cmr.00143-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024] Open
Abstract
SUMMARYDiabetic foot infections (DFI) are a public health problem worldwide. DFI are polymicrobial, biofilm-associated infections involving complex bacterial communities organized in functional equivalent pathogroups, all including anaerobes. Indeed, multiple pathophysiological factors favor the growth of anaerobes in this context. However, the prevalence, role, and contribution of anaerobes in wound evolution remain poorly characterized due to their challenging detection. Studies based on culture reviewed herein showed a weighted average of 17% of patients with anaerobes. Comparatively, the weighted average of patients with anaerobes identified by 16S rRNA gene sequencing was 83.8%. Culture largely underestimated not only the presence but also the diversity of anaerobes compared with cultivation-independent approaches but both methods showed that anaerobic Gram-negative bacilli and Gram-positive cocci were the most commonly identified in DFI. Anaerobes were more present in deeper lesions, and their detection was associated with fever, malodorous lesions, and ulcer depth and duration. More specifically, initial abundance of Peptoniphilus spp. was associated with ulcer-impaired healing, Fusobacterium spp. detection was significantly correlated with the duration of DFI, and the presence of Bacteroides spp. was significantly associated with amputation. Antimicrobial resistance of anaerobes in DFI remains slightly studied and warrants more consideration in the context of increasing resistance of the most frequently identified anaerobes in DFI. The high rate of patients with DFI-involving anaerobes, the increased knowledge on the species identified, their virulence factors, and their potential role in wound evolution support recommendations combining debridement and antibiotic therapy effective on anaerobes in moderate and severe DFI.
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Affiliation(s)
- Fanny Villa
- VBIC, INSERM U1047, Univ Montpellier, Service des Maladies Infectieuses et Tropicales, CHU Nîmes, Nîmes, France
| | - Hélène Marchandin
- HydroSciences Montpellier, Univ Montpellier, CNRS, IRD, Service de Microbiologie et Hygiène, Hospitalière, CHU Nîmes, Nîmes, France
| | - Jean-Philippe Lavigne
- VBIC, INSERM U1047, Univ Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, Nîmes, France
| | - Sophie Schuldiner
- VBIC, INSERM U1047, Univ Montpellier, Service des Maladies Métaboliques et Endocriniennes, CHU Nîmes, Nîmes, France
| | | | - Albert Sotto
- VBIC, INSERM U1047, Univ Montpellier, Service des Maladies Infectieuses et Tropicales, CHU Nîmes, Nîmes, France
| | - Paul Loubet
- VBIC, INSERM U1047, Univ Montpellier, Service des Maladies Infectieuses et Tropicales, CHU Nîmes, Nîmes, France
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Boiten KE, Notermans DW, Rentenaar RJ, van Prehn J, Bode LGM, Maat I, van der Zwet W, Jansz A, Siebers TJH, Rossen JWA, de Greeff SC, Hendrickx APA, Kuijper EJ, Veloo ACM. Antimicrobial susceptibility profile of clinically relevant Bacteroides, Phocaeicola, Parabacteroides and Prevotella species, isolated by eight laboratories in the Netherlands. J Antimicrob Chemother 2024; 79:868-874. [PMID: 38394460 PMCID: PMC10984934 DOI: 10.1093/jac/dkae043] [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: 10/31/2023] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
OBJECTIVES Recently, reports on antimicrobial-resistant Bacteroides and Prevotella isolates have increased in the Netherlands. This urged the need for a surveillance study on the antimicrobial susceptibility profile of Bacteroides, Phocaeicola, Parabacteroides and Prevotella isolates consecutively isolated from human clinical specimens at eight different Dutch laboratories. METHODS Each laboratory collected 20-25 Bacteroides (including Phocaeicola and Parabacteroides) and 10-15 Prevotella isolates for 3 months. At the national reference laboratory, the MICs of amoxicillin, amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem, metronidazole, clindamycin, tetracycline and moxifloxacin were determined using agar dilution. Isolates with a high MIC of metronidazole or a carbapenem, or harbouring cfiA, were subjected to WGS. RESULTS Bacteroides thetaiotaomicron/faecis isolates had the highest MIC90 values, whereas Bacteroides fragilis had the lowest MIC90 values for amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem and moxifloxacin. The antimicrobial profiles of the different Prevotella species were similar, except for amoxicillin, for which the MIC50 ranged from 0.125 to 16 mg/L for Prevotella bivia and Prevotella buccae, respectively. Three isolates with high metronidazole MICs were sequenced, of which one Bacteroides thetaiotaomicron isolate harboured a plasmid-located nimE gene and a Prevotella melaninogenica isolate harboured a nimA gene chromosomally.Five Bacteroides isolates harboured a cfiA gene and three had an IS element upstream, resulting in high MICs of carbapenems. The other two isolates harboured no IS element upstream of the cfiA gene and had low MICs of carbapenems. CONCLUSIONS Variations in resistance between species were observed. To combat emerging resistance in anaerobes, monitoring resistance and conducting surveillance are essential.
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Affiliation(s)
- K E Boiten
- University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, University of Groningen, Groningen, The Netherlands
| | - D W Notermans
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, The Netherlands
| | - R J Rentenaar
- Department of Medical Microbiology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - J van Prehn
- Department of Medical Microbiology, Leiden University Center for Infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - L G M Bode
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center (Erasmus MC), Rotterdam, The Netherlands
| | - I Maat
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - W van der Zwet
- Department of Medical Microbiology, Infectious Diseases and Infection Prevention, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - A Jansz
- PAMM Laboratory of Medical Microbiology, Veldhoven, The Netherlands
| | - T J H Siebers
- University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, University of Groningen, Groningen, The Netherlands
- Department of Medical Microbiology, Certe, Groningen, The Netherlands
| | - J W A Rossen
- University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, University of Groningen, Groningen, The Netherlands
- Laboratory of Medical Microbiology and Infectious Diseases, and Isala Academy, Isala Hospital, Zwolle, The Netherlands
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, USA
| | - S C de Greeff
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - A P A Hendrickx
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - E J Kuijper
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
- Department of Medical Microbiology, Leiden University Center for Infectious Diseases, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - A C M Veloo
- University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, University of Groningen, Groningen, The Netherlands
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Dubreuil LJ. Fifty years devoted to anaerobes: historical, lessons, and highlights. Eur J Clin Microbiol Infect Dis 2024; 43:1-15. [PMID: 37973693 DOI: 10.1007/s10096-023-04708-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/08/2023] [Indexed: 11/19/2023]
Abstract
Renew interest and enthusiasm for anaerobes stem from both technological improvements (culture media, production of an adequate anaerobic atmosphere, identification methods) and greater awareness on the part of clinicians. Anaerobic infections were historically treated empirically, targeting the species known to be involved in each type of infection. Prevotella, fusobacteria, and Gram-positive cocci (GPAC) were considered responsible for infections above the diaphragm whereas for intra-abdominal infections, Bacteroides of the fragilis group (BFG), GPAC and clostridia were predominantly implicated. The antibiotic susceptibility of anaerobes was only taken into consideration by the clinician in the event of treatment failure or when faced with infections by multidrug-resistant bacteria (MDR). The evolution of antibiotic resistance together with clinical failures due to the absence of detection of hetero-resistant clones has resulted in a greater need for accessible antibiotic susceptibility testing (AST) and disc diffusion method. Improved isolation and identification of anaerobes, along with the availability of accessible and robust methods for performing AST, will ensure that treatment, whether empirical or guided by an antibiogram, will lead to better outcomes for anaerobic infections.
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Affiliation(s)
- Luc J Dubreuil
- Clinical Microbiology Department, Faculty of Pharmacy, University of Lille, Lille, France.
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6
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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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First large-scale study of antimicrobial susceptibility data, and genetic resistance determinants, in Fusobacterium necrophorum highlighting the importance of continuing focused susceptibility trend surveillance. Anaerobe 2023; 80:102717. [PMID: 36871786 DOI: 10.1016/j.anaerobe.2023.102717] [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: 11/24/2022] [Revised: 02/10/2023] [Accepted: 02/12/2023] [Indexed: 03/07/2023]
Abstract
OBJECTIVES The objective of the study was to explore antimicrobial resistance gene determinant, and phenotypic antibiotic susceptibility, data for Fusobacterium necrophorum from a collection of UK strains. Antimicrobial resistance genes detected in publicly available assembled whole genome sequences were investigated for comparison. METHODS Three hundred and eighty five F. necrophorum strains (1982-2019) were revived from cryovials (Prolab). Subsequent to sequencing (Illumina) and quality checking, 374 whole genomes were available for analysis. Genomes were interrogated, using BioNumerics (bioMérieux; v 8.1), for the presence of known antimicrobial resistance genes (ARGs). Agar dilution susceptibility results for 313 F. necrophorum isolates (2016-2021) were also examined. RESULTS The phenotypic data for the 313 contemporary strains demonstrated potential resistance to penicillin in three isolates, using EUCAST v 11.0 breakpoints, and 73 (23%) strains using v 13.0 analysis. All strains were susceptible to multiple agents using v 11.0 guidance other than clindamycin (n = 2). Employing v 13.0 breakpoints, metronidazole (n = 3) and meropenem (n = 13) resistance were also detected. The tet(O), tet(M), tet(40), aph(3')-III, ant(6)-la and blaOXA-85 ARGs were present in publicly available genomes. tet(M), tet(32), erm(A) and erm(B) were found within the UK strains, with correspondingly raised clindamycin and tetracycline minimum inhibitory concentrations. CONCLUSIONS Susceptibility to antibiotics recommended for the treatment of F. necrophorum infections should not be assumed. With evidence of potential ARG transmission from oral bacteria, and the detection of a transposon-mediated beta-lactamase resistance determinant in F. necrophorum, surveillance of both phenotypic and genotypic antimicrobial susceptibility trends must continue, and increase.
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8
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Boiten KE, Kuijper EJ, Schuele L, van Prehn J, Bode LGM, Maat I, van Asten SAV, Notermans DW, Rossen JWA, Veloo ACM. Characterization of mobile genetic elements in multidrug-resistant Bacteroides fragilis isolates from different hospitals in the Netherlands. Anaerobe 2023; 81:102722. [PMID: 37001724 DOI: 10.1016/j.anaerobe.2023.102722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 03/31/2023]
Abstract
OBJECTIVES Five human clinical multidrug-resistant (MDR) Bacteroides fragilis isolates, including resistance to meropenem and metronidazole, were recovered at different hospitals in the Netherlands between 2014 and 2020 and sent to the anaerobic reference laboratory for full characterization. METHODS Isolates were recovered from a variety of clinical specimens from patients with unrelated backgrounds. Long- and short-read sequencing was performed, followed by a hybrid assembly to study the presence of mobile genetic elements (MGEs) and antimicrobial resistance genes (ARGs). RESULTS A cfxA gene was present on a transposon (Tn) similar to Tn4555 in two isolates. In two isolates a novel Tn was present with the cfxA gene. Four isolates harbored a nimE gene, located on a pBFS01_2 plasmid. One isolate contained a novel plasmid carrying a nimA gene with IS1168. The tetQ gene was present on novel conjugative transposons (CTns) belonging to the CTnDOT family. Two isolates harbored a novel plasmid with tetQ. Other ARGs in these isolates, but not on an MGE, were: cfiA, ermF, mef(EN2), and sul2. ARGs harboured differed between isolates and corresponded with the observed phenotypic resistance. CONCLUSIONS Novel CTns, Tns, and plasmids were encountered in the five MDR B. fragilis isolates, complementing our knowledge on MDR and horizontal gene transfer in anaerobic bacteria.
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Affiliation(s)
- K E Boiten
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, the Netherlands.
| | - E J Kuijper
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Department of Medical Microbiology, Leiden University Center for Infectious Diseases, Leiden University Medical Center (LUMC), Leiden, the Netherlands
| | - L Schuele
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, the Netherlands
| | - J van Prehn
- Department of Medical Microbiology, Leiden University Center for Infectious Diseases, Leiden University Medical Center (LUMC), Leiden, the Netherlands
| | - L G M Bode
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center (Erasmus MC), Rotterdam, the Netherlands
| | - I Maat
- Radboud University Medical Center, Department of Medical Microbiology, Nijmegen, the Netherlands
| | - S A V van Asten
- Haga Ziekenhuis, Department of Medical Microbiology, Den Haag, the Netherlands
| | - D W Notermans
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - J W A Rossen
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, the Netherlands; Laboratory of Medical Microbiology and Infectious Diseases, Isala Hospital, Zwolle, the Netherlands; Department of Pathology, University of Utah School of Medicine, Salt Lake City, USA
| | - A C M Veloo
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology and Infection Prevention, Groningen, the Netherlands
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9
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Cao Y, Li Y, Guo B, Zhang J, Wu X, Yu J, Cao G, Fan Y, Wu H. Population pharmacokinetics of levornidazole in healthy subjects and patients, and sequential dosing regimen proposal using pharmacokinetic/pharmacodynamic analysis. Int J Antimicrob Agents 2023; 61:106754. [PMID: 36773938 DOI: 10.1016/j.ijantimicag.2023.106754] [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: 06/24/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 02/12/2023]
Abstract
Although sequential treatment with levornidazole has been used for anaerobic infection in clinical practice, there is no evidence-based dosing regimen. This study aimed to evaluate the pharmacokinetics (PK) of levornidazole in healthy subjects and patients, and to propose an evidence-based sequential dosing regimen by pharmacokinetic/pharmacodynamic (PK/PD) analysis. A population PK model was built using the data of 116 Chinese subjects, including 88 healthy young subjects, 12 healthy elderly subjects, and 16 patients with intra-abdominal anaerobic infection. PK/PD analysis was performed combining the minimum inhibitory concentration (MIC) values of levornidazole against 375 anaerobic strains. Four sequential dosing regimens (500 mg q12h, 1000 mg loading dose followed by 500 mg q12h, 750 mg q24h, and 1000 mg q24h) were evaluated in terms of cumulative fraction of response (CFR) and probability of target attainment (PTA) by Monte Carlo simulation. The concentration data of levornidazole and its active metabolites were described adequately by two- and one-compartment models, respectively. Body weight was identified as a significant covariate of levornidazole clearance. Simulations showed that satisfactory PTA (>90%) was achieved for the four dosing regimens when MIC ≤1 mg/L. Considering the simulation results, patients' safety and compliance, levornidazole 750 mg intravenous infusion q24h for 2 days followed by 750 mg oral dose q24h for 5 days was optimal for Bacteroides spp. with an identified MIC ≤1 mg/L.
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Affiliation(s)
- Yuran Cao
- Phase I Clinical Research Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yi Li
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China; Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission, Shanghai, China
| | - Beining Guo
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China; Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission, Shanghai, China.
| | - Jing Zhang
- Phase I Clinical Research Center, Huashan Hospital, Fudan University, Shanghai, China; Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China; Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission, Shanghai, China
| | - Xiaojie Wu
- Phase I Clinical Research Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Jicheng Yu
- Phase I Clinical Research Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Guoying Cao
- Phase I Clinical Research Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yaxin Fan
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China; Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission, Shanghai, China
| | - Hailan Wu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China; Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission, Shanghai, China
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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: 0] [Impact Index Per Article: 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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Umemura T, Hagihara M, Mori T, Mikamo H. In Vitro Efficacy of Antibiotic Combinations with Carbapenems and Other Agents against Anaerobic Bacteria. Antibiotics (Basel) 2022; 11:antibiotics11030292. [PMID: 35326756 PMCID: PMC8944673 DOI: 10.3390/antibiotics11030292] [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: 01/16/2022] [Revised: 02/18/2022] [Accepted: 02/18/2022] [Indexed: 02/01/2023] Open
Abstract
We investigated the in vitro efficacy of combinations of carbapenems with clindamycin (CLDM) and minocycline (MINO) against Bacteroides fragilis and Peptostreptococcus species. We selected the carbapenems imipenem, meropenem, panipenem, doripenem, and biapenem. To evaluate the antibiotic efficacy of these combination regimens, the fractional inhibitory concentration index (FICI) was calculated against clinical isolates. Consequently, combination regimens of each carbapenem with CLDM or MINO showed synergistic or additive effects against 83.3−100.0% and no antagonistic effects against P. anaerobius isolates. However, against the B. fragilis group (B. fragilis, B. thetaiotaomicron, and Parabacteroides distasonis), although the combination with other carbapenems and CLDM or MINO did not show remarkable synergistic effects, the combination regimen of IPM with CLDM or MINO indicated mainly additive antibiotic efficacies (FICIs: >0.5 to ≤1.0) to B. fragilis groups. Then, antagonistic effects were admitted in only 5.6% of B. fragilis groups. The effectiveness of antibiotic combination therapy against pathogenic anaerobes has remained unclear. Then, our results can provide new insights to explore the effective combination regimens against multidrug-resistant anaerobic bacteria as empirical and definitive therapies, while this study used only carbapenem susceptible isolates. Hence, further studies are needed to use highly antibiotic-resistant anaerobic isolates to carbapenems.
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Affiliation(s)
- Takumi Umemura
- Department of Clinical Infectious Diseases, Aichi Medical University, Nagakute 480-1195, Japan; (T.U.); (M.H.); (T.M.)
| | - Mao Hagihara
- Department of Clinical Infectious Diseases, Aichi Medical University, Nagakute 480-1195, Japan; (T.U.); (M.H.); (T.M.)
- Department of Molecular Epidemiology and Biomedical Sciences, Aichi Medical University, Nagakute 480-1195, Japan
| | - Takeshi Mori
- Department of Clinical Infectious Diseases, Aichi Medical University, Nagakute 480-1195, Japan; (T.U.); (M.H.); (T.M.)
| | - Hiroshige Mikamo
- Department of Clinical Infectious Diseases, Aichi Medical University, Nagakute 480-1195, Japan; (T.U.); (M.H.); (T.M.)
- Correspondence: ; Tel./Fax: +81-561-61-1842
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