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Ferraris L, Delannoy J, Mazuet C, Diancourt L, Mesa-Schein V, Barbut F, Aires J. Clostridium neonatale antimicrobial susceptibility, genetic resistance determinants, and genotyping: a multicentre spatiotemporal retrospective analysis. J Antimicrob Chemother 2024; 79:271-279. [PMID: 38084883 PMCID: PMC10832599 DOI: 10.1093/jac/dkad369] [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: 07/04/2023] [Accepted: 11/21/2023] [Indexed: 02/02/2024] Open
Abstract
BACKGROUND Clostridium neonatale was isolated during an outbreak of neonatal necrotizing enterocolitis (NEC) in 2002. C. neonatale was validated as a new species within the genus Clostridium sensu stricto in 2018. In the present study, we evaluated the antimicrobial susceptibility, genetic determinants of resistance, and phylogenetic relationships of a collection of clinical isolates of C. neonatale. METHODS C. neonatale strains (n = 68) were isolated from the stools of preterm neonates who either developed NEC or were asymptomatic carriers of C. neonatale in different periods and in different hospitals. Antimicrobial susceptibility was determined by the disc diffusion method. The MICs of clindamycin, cefotaxime and tetracycline were determined. Genetic determinants of resistance were screened by PCR (n = 68) and WGS (n = 35). Genotyping of the isolates was performed by MLST. RESULTS Antimicrobial resistance was found to clindamycin (n = 24; 35%), cefotaxime (n = 7; 10%) and tetracycline (n = 1; 1%). One clindamycin-resistant isolate carried erm(B) by PCR. In addition, one isolate carrying tet(M) was tetracycline resistant (MIC = 16 mg/L) and 44 isolates carrying either tet(O), tet(32) or tet(M) were tetracycline susceptible (MICs < 16 mg/L). MLST showed that ST2 and ST15 were significantly associated with tet(32) (P < 0.0001) and tet(O) (P < 0.0001), respectively. From WGS, we identified aph(3')-IIa and blaTEM-116 genes and a blaCBP-1-like gene. CONCLUSIONS C. neonatale is susceptible to anti-anaerobic molecules but resistant to clindamycin, cefotaxime and tetracycline. Genes encoding tetracycline ribosomal protection, macrolide-lincosamide-streptogramin B rRNA methyltransferase, aminoglycoside 3'-phosphotransferase and β-lactamases have been identified in genomic regions flanked by mobile genetic elements.
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Affiliation(s)
- Laurent Ferraris
- Faculté de Pharmacie de Paris, Université Paris Cité, INSERM, UMR-S 1139 (3PHM), Paris F-75006, France
| | - Johanne Delannoy
- Faculté de Pharmacie de Paris, Université Paris Cité, INSERM, UMR-S 1139 (3PHM), Paris F-75006, France
| | - Christelle Mazuet
- Institut Pasteur, Université Paris Cité, Centre National de Référence des Bactéries anaérobies et Botulisme, Paris F-75015, France
| | - Laure Diancourt
- Institut Pasteur, Université Paris Cité, Centre National de Référence des Bactéries anaérobies et Botulisme, Paris F-75015, France
| | - Victoria Mesa-Schein
- Faculté de Pharmacie de Paris, Université Paris Cité, INSERM, UMR-S 1139 (3PHM), Paris F-75006, France
| | - Frédéric Barbut
- Faculté de Pharmacie de Paris, Université Paris Cité, INSERM, UMR-S 1139 (3PHM), Paris F-75006, France
| | - Julio Aires
- Faculté de Pharmacie de Paris, Université Paris Cité, INSERM, UMR-S 1139 (3PHM), Paris F-75006, France
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Kitagawa H, Tadera K, Omori K, Nomura T, Shigemoto N, Ohge H. A case of bacteremia caused by Dialister micraerophilus with Enterocloster clostridioformis and Eggerthella lenta in a patient with pyometra. BMC Infect Dis 2024; 24:128. [PMID: 38267864 PMCID: PMC10809547 DOI: 10.1186/s12879-024-08999-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 01/09/2024] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND Infection by Dialister micraerophilus, an obligate anaerobic gram-negative bacillus, has rarely been described, and its clinical characteristics remain unclear. CASE PRESENTATION We report a case of bacteremia caused by D. micraerophilus, Enterocloster clostridioformis, and Eggerthella lenta in a 47-year-old woman, associated with pyometra. D. micraerophilus was identified using 16S rRNA gene sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. D. micraerophilus was detected by polymerase chain reaction using D. micraerophilus-specific primers and E. clostridioformis and E. lenta was isolated from the drainage pus sample obtained from the pyometra uterus. The patient achieved a cure after abscess drainage and 2-week antibiotic treatment. CONCLUSIONS To the best of our knowledge, this is the first report of D. micraerophilus bacteremia. D. micraerophilus may be associated with gynecological infections. Clinicians should consider both oral and gynecological sites when searching to identify the focus of D. micraerophilus infection.
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Affiliation(s)
- Hiroki Kitagawa
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan.
- Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University , Hiroshima, Japan.
- Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan.
| | - Kayoko Tadera
- Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan
- Section of Clinical Laboratory, Division of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
- Division of Laboratory Medicine, Hiroshima University Hospital, Hiroshima, Japan
| | - Keitaro Omori
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
| | - Toshihito Nomura
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
| | - Norifumi Shigemoto
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
- Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University , Hiroshima, Japan
- Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan
- Translational Research Center, Hiroshima University, Hiroshima, Japan
| | - Hiroki Ohge
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
- Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan
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Ligero-López J, Rubio-Mora E, Ruiz-Bastián MD, Quiles-Melero MI, Cacho-Calvo J, Cendejas-Bueno E. Antimicrobial susceptibility testing of anaerobic bacteria causing bacteremia: A 13-year (2010-2022) retrospective study in a tertiary hospital. Anaerobe 2023; 84:102803. [PMID: 37984560 DOI: 10.1016/j.anaerobe.2023.102803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 11/07/2023] [Accepted: 11/15/2023] [Indexed: 11/22/2023]
Abstract
Infections from anaerobic microorganisms result from breached mucosal barriers, posing a significant mortality risk. A retrospective study at Hospital Universitario La Paz (Madrid) from 2010 to 2022 analyzed 491 (6.17 %) anaerobic bacteremia cases out of 7956 significant bacteremia cases among 171,833 blood culture requests. Bacteroides fragilis was the most frequently isolated species (28.3 %), followed by Clostridium perfringens (13.6 %). B. fragilis showed good susceptibility to amoxicillin/ clavulanic acid (86 %), piperacillin/tazobactam (86 %), and metronidazole (87.7 %). In general, non-fragilis Bacteroides species showed low susceptibility to penicillin (7 %), amoxicillin (17.5 %), and clindamycin (64.9 %). Of our 13 non-perfringens Clostridium isolates, four exhibited resistance to penicillin and four showed resistance to clindamycin. Lactobacillus species were highly susceptible to antibiotics tested. Prevotella spp. showed low susceptibility to penicillin (20 %), amoxicillin (20 %), and clindamycin (40 %). The study contributes valuable data for monitoring and improving anaerobic bacteremia treatment.
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Affiliation(s)
- Jorge Ligero-López
- Clinical Microbiology Department, Hospital Universitario La Paz, IdiPaz, Madrid, Spain
| | - Eduardo Rubio-Mora
- Clinical Microbiology Department, Hospital Universitario La Paz, IdiPaz, Madrid, Spain
| | | | | | - Juana Cacho-Calvo
- Clinical Microbiology Department, Hospital Universitario La Paz, IdiPaz, Madrid, Spain
| | - Emilio Cendejas-Bueno
- Clinical Microbiology Department, Hospital Universitario La Paz, IdiPaz, Madrid, Spain; CIBERINFEC, Instituto de Salud Carlos III, Madrid, Spain.
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Shariff M, Ramengmawi E. Antimicrobial resistance pattern of anaerobic bacteria causing lower respiratory tract infections. BMC Microbiol 2023; 23:301. [PMID: 37872502 PMCID: PMC10591390 DOI: 10.1186/s12866-023-03059-6] [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: 08/03/2023] [Accepted: 10/12/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND Anaerobes are normal flora of the human body. However, they can cause serious infections in humans. Anaerobic bacteria are known to cause respiratory infections like pneumonia and acute exacerbation of chronic lower airway infections. These are often missed due to the complexity of their isolation and identification. Hence, this study aimed to study anaerobes causing respiratory tract infections and determine their antibiotic susceptibility. MATERIALS & METHODS Clinical specimens such as bronchial aspirates and pleural aspirates collected from patients with respiratory diseases attending Vallabhbhai Patel Chest Institute were processed, the anaerobes isolated were identified, and their susceptibilities to various groups of antimicrobials were studied using standard microbiological methods. RESULTS Three hundred and fourteen patients were included in the study, 154 males and 160 females. Of these 314 patients, 148 (47%) yielded anaerobes in their clinical samples. Seventy patients had more than one type of anaerobic organism. Hence, 235 isolates were recovered belonging to as many as 17 genera. The MIC of seven antibiotics on 154 isolates was tested. The isolates belonged mostly to the genera Bacteroides, Prevotella, Veillonella, and Actinomyces. Variable resistance was observed to most classes of antibiotics by many genera. CONCLUSIONS Metronidazole is commonly used against anaerobes, but the study showed that the isolates were 20-30% resistant to the antibiotic. Starting this as an empirical therapy might lead to treatment failure.
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Affiliation(s)
- Malini Shariff
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007 India
| | - Elizabeth Ramengmawi
- Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110007 India
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Reissier S, Penven M, Guérin F, Cattoir V. Recent Trends in Antimicrobial Resistance among Anaerobic Clinical Isolates. Microorganisms 2023; 11:1474. [PMID: 37374976 DOI: 10.3390/microorganisms11061474] [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: 05/10/2023] [Revised: 05/26/2023] [Accepted: 05/28/2023] [Indexed: 06/29/2023] Open
Abstract
Anaerobic bacteria are normal inhabitants of the human commensal microbiota and play an important role in various human infections. Tedious and time-consuming, antibiotic susceptibility testing is not routinely performed in all clinical microbiology laboratories, despite the increase in antibiotic resistance among clinically relevant anaerobes since the 1990s. β-lactam and metronidazole are the key molecules in the management of anaerobic infections, to the detriment of clindamycin. β-lactam resistance is usually mediated by the production of β-lactamases. Metronidazole resistance remains uncommon, complex, and not fully elucidated, while metronidazole inactivation appears to be a key mechanism. The use of clindamycin, a broad-spectrum anti-anaerobic agent, is becoming problematic due to the increase in resistance rate in all anaerobic bacteria, mainly mediated by Erm-type rRNA methylases. Second-line anti-anaerobes are fluoroquinolones, tetracyclines, chloramphenicol, and linezolid. This review aims to describe the up-to-date evolution of antibiotic resistance, give an overview, and understand the main mechanisms of resistance in a wide range of anaerobes.
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Affiliation(s)
- Sophie Reissier
- Rennes University Hospital, Department of Clinical Microbiology, F-35033 Rennes, France
- UMR_S1230 BRM, Inserm, University of Rennes, F-35043 Rennes, France
| | - Malo Penven
- Rennes University Hospital, Department of Clinical Microbiology, F-35033 Rennes, France
- UMR_S1230 BRM, Inserm, University of Rennes, F-35043 Rennes, France
| | - François Guérin
- Rennes University Hospital, Department of Clinical Microbiology, F-35033 Rennes, France
- UMR_S1230 BRM, Inserm, University of Rennes, F-35043 Rennes, France
| | - Vincent Cattoir
- Rennes University Hospital, Department of Clinical Microbiology, F-35033 Rennes, France
- UMR_S1230 BRM, Inserm, University of Rennes, F-35043 Rennes, France
- CHU de Rennes, Service de Bactériologie-Hygiène Hospitalière, 2 Rue Henri Le Guilloux, CEDEX 9, F-35033 Rennes, France
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Acker E, George M, Farooqi T, Raval M, Ramani A. Polymicrobial anaerobic sepsis due to Bacteroides fragilis, Eggerthella lenta, Ruminoccocus gnavus, and Bilophila wadsworthia in a patient with myeloproliferative neoplasm. Anaerobe 2022; 78:102641. [PMID: 36108892 DOI: 10.1016/j.anaerobe.2022.102641] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 08/07/2022] [Accepted: 09/07/2022] [Indexed: 12/01/2022]
Abstract
We report a rare case of polymicrobial anaerobic bacteremia caused by four different gut anaerobes: Bacteroides fragilis, Eggerthella lenta, Bilophila wadsworthia, and Ruminococcus gnavus. Early initiation of appropriate therapy and species identification with matrix assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS) resulted in full recovery from the infection. Our case highlights the clinical significance of polymicrobial cultures and the importance of performing anaerobic cultures for blood specimens to ensure proper identification and treatment.
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Affiliation(s)
- Emily Acker
- Albany Medical Center, 43 New Scotland Avenue, Albany, NY, 12208, United States.
| | - Mary George
- Albany Medical Center, 43 New Scotland Avenue, Albany, NY, 12208, United States.
| | - Tariq Farooqi
- New York Oncology & Hematology, Albany Medical Center, 43 New Scotland Avenue, NY, 12208, United States.
| | - Mihir Raval
- New York Oncology & Hematology, Albany Medical Center, 43 New Scotland Avenue, NY, 12208, United States.
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Watanabe T, Hara Y, Yoshimi Y, Yokoyama-Kokuryo W, Fujita Y, Yokoe M, Noguchi Y. Application of MALDI-TOF MS to assess clinical characteristics, risk factors, and outcomes associated with anaerobic bloodstream infection: a retrospective observational study. Ann Clin Microbiol Antimicrob 2021; 20:42. [PMID: 34107966 PMCID: PMC8191184 DOI: 10.1186/s12941-021-00449-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/02/2021] [Indexed: 11/28/2022] Open
Abstract
Background Correctly identifying anaerobic bloodstream infections (BSIs) is difficult. However, a new technique, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), enables more accurate identification and appropriate treatment. Anaerobic BSIs identified by MALDI-TOF MS were retrospectively analyzed to determine the clinical and microbiological features and patient outcomes based on the anaerobic genera or group. Methods Medical records of patients with anaerobic BSIs were used to conduct a single-center retrospective cohort study from January 2016 to December 2020 in Nagoya, Japan. Multivariate logistic regression analysis was performed to determine the independent risk factors for in-hospital mortality. Results Of the 215 patients with anaerobic BSIs, 31 had multiple anaerobic organisms in the blood culture, including 264 total episodes of anaerobic BSIs. Bacteroides spp. were isolated the most (n = 74), followed by gram-positive non-spore-forming bacilli (n = 57), Clostridium spp. (n = 52), gram-positive anaerobic cocci (GPAC) (n = 27), and gram-negative cocci (n = 7). The median patient age was 76 years; 56.7% were male. The most common focal infection site was intra-abdominal (36.7%). The in-hospital mortality caused by anaerobic BSIs was 21.3%, and was highest with Clostridium spp. (36.5%) and lowest with GPAC (3.7%). Age, solid tumors, and Clostridium spp. were independent risk factors for in-hospital mortality. Conclusions We identified current anaerobic BSI trends using MALDI-TOF MS and reported that mortality in patients with anaerobic BSIs patients was highest with Clostridium spp. infections.
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Affiliation(s)
- Tsuyoshi Watanabe
- Division of Rheumatology, Chubu Rosai Hospital, 2-10-15, Komei-cho, Minato-ku, Nagoya, Aichi, 455-8530, Japan.
| | - Yuki Hara
- Division of Clinical Laboratory, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Aichi, 466-8650, Japan
| | - Yusuke Yoshimi
- Division of General Internal Medicine, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Aichi, 466-8650, Japan
| | - Waka Yokoyama-Kokuryo
- Division of Rheumatology, Chubu Rosai Hospital, 2-10-15, Komei-cho, Minato-ku, Nagoya, Aichi, 455-8530, Japan
| | - Yoshiro Fujita
- Division of Rheumatology, Chubu Rosai Hospital, 2-10-15, Komei-cho, Minato-ku, Nagoya, Aichi, 455-8530, Japan.,Division of Nephrology, Chubu Rosai Hospital, 2-10-15, Komei-cho, Minato-ku, Nagoya, Aichi, 455-8530, Japan
| | - Masamichi Yokoe
- Division of General Internal Medicine, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Aichi, 466-8650, Japan
| | - Yoshinori Noguchi
- Division of General Internal Medicine, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Aichi, 466-8650, Japan
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Jasemi S, Emaneini M, Ahmadinejad Z, Fazeli MS, Sechi LA, Sadeghpour Heravi F, Feizabadi MM. Antibiotic resistance pattern of Bacteroides fragilis isolated from clinical and colorectal specimens. Ann Clin Microbiol Antimicrob 2021; 20:27. [PMID: 33892721 PMCID: PMC8066845 DOI: 10.1186/s12941-021-00435-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/16/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Bacteroides fragilis is a part of the normal gastrointestinal flora, but it is also the most common anaerobic bacteria causing the infection. It is highly resistant to antibiotics and contains abundant antibiotic resistance mechanisms. METHODS The antibiotic resistance pattern of 78 isolates of B. fragilis (22 strains from clinical samples and 56 strains from the colorectal tissue) was investigated using agar dilution method. The gene encoding Bacteroides fargilis toxin bft, and antibiotic resistance genes were targeted by PCR assay. RESULTS The highest rate of resistance was observed for penicillin G (100%) followed by tetracycline (74.4%), clindamycin (41%) and cefoxitin (38.5%). Only a single isolate showed resistance to imipenem which contained cfiA and IS1186 genes. All isolates were susceptible to metronidazole. Accordingly, tetQ (87.2%), cepA (73.1%) and ermF (64.1%) were the most abundant antibiotic-resistant genes identified in this study. MIC values for penicillin, cefoxitin and clindamycin were significantly different among isolates with the cepA, cfxA and ermF in compare with those lacking such genes. In addition, 22.7 and 17.8% of clinical and GIT isolates had the bft gene, respectively. CONCLUSIONS The finding of this study shows that metronidazole is highly in vitro active agent against all of B. fragilis isolates and remain the first-line antimicrobial for empirical therapy.
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Affiliation(s)
- Seyedesomaye Jasemi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Poursina Street, Engelab-e-Eslami Avenue, Tehran, Iran
| | - Mohammad Emaneini
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Poursina Street, Engelab-e-Eslami Avenue, Tehran, Iran
| | - Zahra Ahmadinejad
- Department of Infectious Diseases, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sadegh Fazeli
- Department of Surgery, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Leonardo A Sechi
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Fatemah Sadeghpour Heravi
- Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Mohammad Mehdi Feizabadi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Poursina Street, Engelab-e-Eslami Avenue, Tehran, Iran. .,Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
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Cobo F, Borrego J, Gómez E, Casanovas I, Calatrava E, Foronda C, Navarro-Marí JM. Clinical Findings and Antimicrobial Susceptibility of Anaerobic Bacteria Isolated in Bloodstream Infections. Antibiotics (Basel) 2020; 9:antibiotics9060345. [PMID: 32575377 PMCID: PMC7345846 DOI: 10.3390/antibiotics9060345] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/16/2020] [Accepted: 06/17/2020] [Indexed: 12/19/2022] Open
Abstract
The objectives of this study were to report on the antimicrobial susceptibility of 141 clinically significant anaerobic bacteria isolated from bloodstream infections between January 2016 and April 2020 in a tertiary-care hospital in Granada (Spain) and to describe the main clinical features of the patients. Species identification was performed by MALDI-TOF MS (Bruker Daltonics, Billerica, MA, USA). Antimicrobial susceptibility tests were performed against penicillin, amoxicillin-clavulanic acid, imipenem, moxifloxacin, clindamycin, metronidazole, and piperacillin-tazobactam using the gradient diffusion technique and EUCAST breakpoints, except for moxifloxacin (CLSI breakpoints). The most frequent anaerobes were Bacteroides (43.9%, n = 62), Clostridium (24.1%, n = 34) and Gram-positive anaerobic cocci (GPACs) (15.6%, n = 22). Almost all tested anaerobes were susceptible to imipenem and amoxicillin-clavulanic acid, except for Bacteroides. High overall resistance rates to clindamycin were observed, especially for Gram-positive anaerobic cocci (GPACs) (54.5%) and for Bacteroides spp. (45.1%). Overall, low resistance rates to almost all antibiotics were observed for Clostridium. High resistance rates to penicillin were also observed for Gram-positive anaerobic bacilli (GPABs) (44.4%), as well as to metronidazole (22.2%), although only nine isolates were included. Antimicrobial susceptibility testing for anaerobes should always be performed in severe infections, such as those localized in the bloodstream. The information obtained contributes to selecting empirical treatments according with local data on resistance.
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