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Spruijtenburg B, Rezusta A, Houbraken J, Hagen F, de Groot T, Meis JF, Meijer EFJ. Susceptibility Testing of Environmental and Clinical Aspergillus sydowii Demonstrates Potent Activity of Various Antifungals. Mycopathologia 2024; 189:61. [PMID: 38958798 PMCID: PMC11222195 DOI: 10.1007/s11046-024-00869-8] [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: 03/20/2024] [Accepted: 06/13/2024] [Indexed: 07/04/2024]
Abstract
The genus Aspergillus consists of a vast number of medically and environmentally relevant species. Aspergillus species classified in series Versicolores are ubiquitous in the environment and include the opportunistic pathogen Aspergillus sydowii, which is associated with onychomycosis and superficial skin infections. Despite frequent clinical reports of A. sydowii and related series Versicolores species, antifungal susceptibility data are scarce, hampering optimal treatment choices and subsequent patient outcomes. Here, we employed antifungal susceptibility testing (AFST) based on microbroth dilution on a set of 155 series Versicolores strains using the common antifungals amphotericin B, itraconazole, voriconazole, posaconazole, isavuconazole and micafungin with the addition of luliconazole and olorofim. All strains were identified using partial calmodulin gene sequencing, with 145 being A. sydowii, seven A. creber and three A. versicolor, using the latest taxonomic insights. Overall, tested antifungals were potent against the entire strain collection. In comparison to A. fumigatus, azole and amphotericin B MICs were slightly elevated for some strains. AFST with luliconazole and olorofim, here reported for the first time, displayed the highest in vitro activity, making these antifungals interesting alternative drugs but clinical studies are warranted for future therapeutic use.
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Affiliation(s)
- Bram Spruijtenburg
- Radboudumc-CWZ Center of Expertise for Mycology, Weg Door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands
- Canisius-Wilhelmina Hospital (CWZ)/Dicoon, 6532 SZ, Nijmegen, The Netherlands
| | - Antonio Rezusta
- Servicio de Microbiología, Hospital Universitario Miguel Servet, IIS Aragon, Saragossa, Spain
| | - Jos Houbraken
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Ferry Hagen
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
- Institute for Biodiversity and Ecosystems Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Theun de Groot
- Radboudumc-CWZ Center of Expertise for Mycology, Weg Door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands
- Canisius-Wilhelmina Hospital (CWZ)/Dicoon, 6532 SZ, Nijmegen, The Netherlands
| | - Jacques F Meis
- Radboudumc-CWZ Center of Expertise for Mycology, Weg Door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands
- Institute of Translational Research, Cologne Excellence Cluster On Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Excellence Center for Medical Mycology, University of Cologne, Cologne, Germany
| | - Eelco F J Meijer
- Radboudumc-CWZ Center of Expertise for Mycology, Weg Door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands.
- Canisius-Wilhelmina Hospital (CWZ)/Dicoon, 6532 SZ, Nijmegen, The Netherlands.
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Hossain TJ. Methods for screening and evaluation of antimicrobial activity: A review of protocols, advantages, and limitations. Eur J Microbiol Immunol (Bp) 2024; 14:97-115. [PMID: 38648108 PMCID: PMC11097785 DOI: 10.1556/1886.2024.00035] [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: 03/13/2024] [Accepted: 04/05/2024] [Indexed: 04/25/2024] Open
Abstract
Infectious diseases pose a formidable global challenge, compounded by the emergence of antimicrobial resistance. Consequently, researchers are actively exploring novel antimicrobial compounds as potential solutions. This endeavor underscores the pivotal role of methods employed for screening and evaluating antimicrobial activity-a critical step in discovery and characterization of antimicrobial agents. While traditional techniques such as well-diffusion, disk-diffusion, and broth-dilution are commonly utilized in antimicrobial assays, they may encounter limitations concerning reproducibility and speed. Additionally, a diverse array of antimicrobial assays including cross-streaking, poisoned-food, co-culture, time-kill kinetics, resazurin assay, bioautography, etc., are routinely employed in antimicrobial evaluations. Advanced techniques such as flow-cytometry, impedance analysis, and bioluminescent technique may offer rapid and sensitive results, providing deeper insights into the impact of antimicrobials on cellular integrity. However, their higher cost and limited accessibility in certain laboratory settings may present challenges. This article provides a comprehensive overview of assays designed to characterize antimicrobial activity, elucidating their underlying principles, protocols, advantages, and limitations. The primary objective is to enhance understanding of the methodologies designed for evaluating antimicrobial agents in our relentless battle against infectious diseases. By selecting the appropriate antimicrobial testing method, researchers can discern suitable conditions and streamline the identification of effective antimicrobial agents.
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Affiliation(s)
- Tanim Jabid Hossain
- Department of Biochemistry and Molecular Biology, University of Chittagong, Chattogram, Bangladesh
- Biochemistry and Pathogenesis of Microbes – BPM Unit, Laboratory for Health, Omics and Pathway Exploration (HOPE Research), Chattogram, Bangladesh
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Movahedi M, Niakan Z, Shahshahan Z, Hooshmand Meibodi AR, Babak A, Saeidi M. Prophylactic hypogastric arterial ligation before cesarean hysterectomy for controlling complications in pregnant women with placenta adherent abnormality: A randomized controlled clinical trial. JOURNAL OF RESEARCH IN MEDICAL SCIENCES : THE OFFICIAL JOURNAL OF ISFAHAN UNIVERSITY OF MEDICAL SCIENCES 2022; 27:63. [PMID: 36353346 PMCID: PMC9639719 DOI: 10.4103/jrms.jrms_763_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 02/28/2022] [Accepted: 03/07/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Placenta adherent abnormality (PAA) is abnormal attachment of the placenta to the myometrium. This abnormal placenta binding has severe clinical consequences for the mother and the fetus. We investigated the outcomes of hypogastric arterial ligation (HAL) before hysterectomy compared to hysterectomy alone in pregnant women with PAA. MATERIALS AND METHODS In this randomized controlled clinical trial, 70 patients were randomly allocated to HAL along with hysterectomy and hysterectomy alone groups (35 in each Group). The total amount of intraoperative blood loss, the need for intraoperative blood products transfusion, frequency of deep vein thrombosis, duration of surgery, duration of hospitalization, and visceral trauma were compared between 2 Groups. RESULTS Finally, 64 patients completed the study protocol with mean age of 33.84 ± 4.25 years. The study groups were comparable in terms of basic baseline demographic and clinical characteristics. Visceral trauma was less frequently occurred in HAL group compared to hysterectomy alone (0% vs. 15.6%; P = 0.02). Intraoperative blood loss (1525 ± 536.41 cc vs. 2075 ± 889.36 cc; P = 0.001) and were significantly lower in HAL group compared to hysterectomy alone. Duration of operation (179.06 ± 36.28 vs. 197.66 ± 39.47; P = 0.05) and hospitalization (4.97 ± 2.20 vs. 6.10 ± 2.39; P = 0.03) also were significantly lower in HAL group. CONCLUSION Our findings suggest that prophylactic HAL has a protective effect on the reduction of blood loss and less visceral trauma in pregnant women with PAA.
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Affiliation(s)
- Minoo Movahedi
- Department of Obstetrics and Gynecology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Zahra Niakan
- Department of Obstetrics and Gynecology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Zahra Shahshahan
- Department of Obstetrics and Gynecology, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Anahita Babak
- Department of Community and Family Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mahmoud Saeidi
- Department of Surgery, School of Medicine Chamran Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
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Rozaliyani A, Abdullah A, Setianingrum F, Sjamsuridzal W, Wahyuningsih R, Bowolaksono A, Fatril AE, Adawiyah R, Tugiran M, Syam R, Wibowo H, Kosmidis C, Denning DW. Unravelling the Molecular Identification and Antifungal Susceptibility Profiles of Aspergillus spp. Isolated from Chronic Pulmonary Aspergillosis Patients in Jakarta, Indonesia: The Emergence of Cryptic Species. J Fungi (Basel) 2022; 8:411. [PMID: 35448642 PMCID: PMC9024953 DOI: 10.3390/jof8040411] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 12/16/2022] Open
Abstract
Cryptic species of Aspergillus have rapidly increased in the last few decades. Chronic pulmonary aspergillosis (CPA) is a debilitating fungal infection frequently affecting patients with previous TB. The identification and antifungal susceptibility profiles of different species of Aspergillus are important to support the management of CPA. The aim of this study was to describe the molecular and susceptibility profiles of Aspergillus isolated from CPA patients. The species identity of isolates was determined by combined DNA analyses of internal transcribed space (ITS), partial β-tubulin genes, and part of the calmodulin gene. We revealed a high (27%) prevalence of cryptic species among previous tuberculosis patients with persistent symptoms. Twenty-nine (49%) patients met the criteria for diagnosis of CPA with 24% containing Aspergillus cryptic species. This is the first report of five cryptic Aspergillus species from clinical isolates in Indonesia: A. aculea tus, A. neoniger, A. brunneoviolacues, A. welwitschiae, and A. tubingensis. Significantly, there was decreased sensitivity against itraconazole in the CPA group (66% susceptible to itraconazole) compared to the non-CPA group (90% susceptible to itraconazole) (p = 0.003). The species-level characterisation of Aspergillus and its antifungal susceptibility tests demands greater attention to better the management of CPA patients.
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Affiliation(s)
- Anna Rozaliyani
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
- Indonesia Pulmonary Mycoses Centre, Jakarta 10430, Indonesia
| | - Asriyani Abdullah
- Magister Program of Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia;
| | - Findra Setianingrum
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
- Indonesia Pulmonary Mycoses Centre, Jakarta 10430, Indonesia
| | - Wellyzar Sjamsuridzal
- Department of Biology, Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Indonesia, Depok 16424, Indonesia; (W.S.); (A.B.)
| | - Retno Wahyuningsih
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
- Department of Parasitology, Faculty of Medicine, Universitas Kristen, Jakarta 13530, Indonesia
| | - Anom Bowolaksono
- Department of Biology, Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Indonesia, Depok 16424, Indonesia; (W.S.); (A.B.)
| | - Ayu Eka Fatril
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
| | - Robiatul Adawiyah
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
- Indonesia Pulmonary Mycoses Centre, Jakarta 10430, Indonesia
| | - Mulyati Tugiran
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
- Indonesia Pulmonary Mycoses Centre, Jakarta 10430, Indonesia
| | - Ridhawati Syam
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
- Indonesia Pulmonary Mycoses Centre, Jakarta 10430, Indonesia
| | - Heri Wibowo
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia; (F.S.); (R.W.); (A.E.F.); (R.A.); (M.T.); (R.S.); (H.W.)
- Magister Program of Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia;
| | - Chris Kosmidis
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M23 9LT, UK; (C.K.); (D.W.D.)
- Manchester Academic Health Science Centre, Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M23 9LT, UK
| | - David W. Denning
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M23 9LT, UK; (C.K.); (D.W.D.)
- Manchester Academic Health Science Centre, Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M23 9LT, UK
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Omar HS, Abd El-Rahman SN, AlGhannam SM, Reyad NEHA, Sedeek MS. Antifungal Evaluation and Molecular Docking Studies of Olea europaea Leaf Extract, Thymus vulgaris and Boswellia carteri Essential Oil as Prospective Fungal Inhibitor Candidates. Molecules 2021; 26:molecules26206118. [PMID: 34684700 PMCID: PMC8539494 DOI: 10.3390/molecules26206118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 12/05/2022] Open
Abstract
Background: The present study investigated the antifungal activity and mode of action of four Olea europaea leaf extracts, Thymus vulgaris essential oil (EO), and Boswellia carteri EO against Fusarium oxysporum. Methods:Fusarium oxysporum lactucae was detected with the internal transcribed spacer (ITS) region. The chemical compositions of chloroform and dichloromethane extracts of O. europaea leaves and T. vulgaris EO were analyzed using GC-MS analysis. In addition, a molecular docking analysis was used to identify the expected ligands of these extracts against eleven F. oxysporum proteins. Results: The nucleotide sequence of the F. oxysporum lactucae isolate was deposited in GenBank with Accession No. MT249304.1. The T. vulgaris EO, chloroform, dichloromethane and ethanol efficiently inhibited the growth at concentrations of 75.5 and 37.75 mg/mL, whereas ethyl acetate, and B. carteri EO did not exhibit antifungal activity. The GC-MS analysis revealed that the major and most vital compounds of the T. vulgaris EO, chloroform, and dichloromethane were thymol, carvacrol, tetratriacontane, and palmitic acid. Moreover, molecular modeling revealed the activity of these compounds against F. oxysporum. Conclusions: Chloroform, dichloromethane and ethanol, olive leaf extract, and T. vulgaris EO showed a strong effect against F. oxysporum. Consequently, this represents an appropriate natural source of biological compounds for use in healthcare. In addition, homology modeling and docking analysis are the best analyses for clarifying the mechanisms of antifungal activity.
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Affiliation(s)
- Hanaa S. Omar
- Department of Genetics, Faculty of Agriculture, Cairo University, Giza 12613, Egypt
- GMO Laboratory, Faculty of Agriculture, Cairo University, Research Park, CURP, Giza 12613, Egypt
- Correspondence: (H.S.O.); (S.N.A.E.-R.)
| | - Soheir N. Abd El-Rahman
- Crops Technology Research Department, Food Technology Research Institute, Agricultural Research Center, Giza 12619, Egypt
- Correspondence: (H.S.O.); (S.N.A.E.-R.)
| | - Sheikha M. AlGhannam
- Department of Chemistry, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31441, Saudi Arabia;
| | - Nour El-Houda A. Reyad
- Plant Pathology Department, Faculty of Agriculture, Cairo University, Giza 12613, Egypt;
| | - Mohamed S. Sedeek
- Pharmacognosy Department, Faculty of Pharmacy, Cairo University, Giza 11562, Egypt;
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Evaluation of the chemical constituents and potential biological activities of Cunninghamella blakesleeana. Saudi Pharm J 2020; 28:1197-1202. [PMID: 33132713 PMCID: PMC7584793 DOI: 10.1016/j.jsps.2020.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/11/2020] [Indexed: 11/17/2022] Open
Abstract
The aim of this work is to evaluate the chemical constituents and potential biological activists of Cunninghamella blakesleeana. Three fatty acids were isolated using column chromatography and identified as palmitic acid (F1), oleic acid (F2) and stearic acid (F3) in addition to other two steroidal compounds; α-amyrin (A4), and β-sitosterol (A5). Using GC, ten fatty acids were detected the major fatty acid obtained was stearic acid (74.61%) while palmitic acid was the second high percentage (10.35%), and the least percentage obtained was arachidic acid (0.07%). C. blakesleeana extract showed in-vitro antimicrobial activities against some microorganisms. The highest activity of C. blakesleeana total extract was reported against Staphylococcus aureus (18.3 ± 0.03 mm.) followed by Streptococcus pyogenes (15.3 ± 0.05), while the lowest were for both Candida albicans & Pseudomonas aeruginosa (6.7 ± 0.06 and 5.9.0 ± 0.9 mm. respectively). The three isolated compounds (F1-3) showed activities against Staphylococcus aureus, Penicillium expansum, and Salmonella typhimurium only. The highest activity was aganist Staphylococcus aureus (13.0 ± 0.1 mm.). The highest effect was obtained by compound F3 (stearic acid) (15.0 ± 0.5 mm.), and compound F1 (oleic acid) (13.0 ± 0.1 mm.) and F2 (palmitic acid) 11.0 ± 0.3 mm. The total ethanol extract of the investigated fungus was safe up to 5000 mg kg−1 and did not produce any significant change in liver and kidney functions after oral administration (400 mg kg−1) for 14 consecutive days. The results reported the isolation of some fungal new driving compounds which has been not isolated before from Cunninghamella species in addition to their correlated new biological activities.
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Comparison of the MICs Obtained by Gradient Concentration Strip and EUCAST Methods for Four Azole Drugs and Amphotericin B against Azole-Susceptible and -Resistant Aspergillus Section Fumigati Clinical Isolates. Antimicrob Agents Chemother 2020; 64:AAC.01597-19. [PMID: 31844011 DOI: 10.1128/aac.01597-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 12/07/2019] [Indexed: 01/21/2023] Open
Abstract
Reference methods used to assess the drug susceptibilities of Aspergillus fumigatus isolates consisted of EUCAST and CLSI standardized broth microdilution techniques. Considering the increasing rate and the potential impact on the clinical outcome of azole resistance in A. fumigatus, more suitable techniques for routine testing are needed. The gradient concentration strip (GCS) method has been favorably evaluated for yeast testing. The aim of this study was to compare the CGS test with EUCAST broth microdilution for amphotericin B (AMB), posaconazole (PCZ), itraconazole (ITZ), voriconazole (VRZ), and isavuconazole (ISA). A total of 121 Aspergillus section Fumigati strains were collected, including 24 A. fumigatus sensu stricto strains that were resistant to at least one azole drug. MICs were determined using GCS and EUCAST methods. Essential agreement between the 2 methods was considered when MICs fell within ±1 dilution or ±2 dilutions of the 2-fold dilution scale. Categorical agreement was defined as the percentage of strains classified in the same category (susceptible, intermediate, or resistant) with both methods. Essential agreements with ±1 dilution and ±2 dilutions were 96.7, 93.4, 90.0, 89.3, and 95% and 100, 99.2, 100, 97.5, and 100% for AMB, PCZ, ITZ, VRZ, and ISA, respectively. Categorical agreements were 94.3, 86.1, 89.3, and 88.5% for AMB, PCZ, ITZ, and VRZ, respectively. Detection of resistance was missed with the GCS for one strain (4.1%) for PCZ and for 2 strains (8.3%) for ISA. Determination of ITZ MICs using the GCS allowed the detection of 91.7% of azole-resistant strains. The GCS test appears to be a valuable method for screening azole-resistant A. fumigatus clinical isolates.
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Agarwal H, Dowarah B, Agarwala N. A Quick Method for Screening Biocontrol Efficacy of Bacterial Isolates Against Bacterial Wilt Pathogen Ralstonia solanacearum in Tomato. Bio Protoc 2020. [DOI: 10.21769/bioprotoc.3829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Darkoh C, Plants-Paris K, Bishoff D, DuPont HL. Clostridium difficile Modulates the Gut Microbiota by Inducing the Production of Indole, an Interkingdom Signaling and Antimicrobial Molecule. mSystems 2019; 4:e00346-18. [PMID: 30944877 PMCID: PMC6426650 DOI: 10.1128/msystems.00346-18] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 02/27/2019] [Indexed: 02/07/2023] Open
Abstract
Clostridium (Clostridioides) difficile infection (CDI) is associated with dysbiosis. C. difficile has a characteristic propensity to persist and recur 1 to 4 weeks after treatment, but the mechanism is unknown. We hypothesized that C. difficile may persist by manipulating the intestinal microenvironment, thereby hampering gut microbiota reconstitution following antibiotic-mediated dysbiosis. By screening stools from CDI patients for unique markers, a metabolite identified to be indole by mass spectrometry and Fourier transform infrared spectroscopy was identified. The average fecal indole concentration detected in CDI patients (n = 216; mean, 1,684.0 ± 84.4 µM) was significantly higher than in stools of patients with non-C. difficile diarrhea (n = 204; mean, 762.8 ± 53.8 µM). Certain intestinal bacteria, but not C. difficile, produce indole, a potent antimicrobial antioxidant. Remarkably, C. difficile induced other indole-producing gut microbes to produce increasing amounts of indole. Furthermore, a C. difficile accessory gene regulator 1 quorum sensing system mutant cannot induce indole, but complementation of the mutant strain with the wild-type gene restored its ability to induce indole production. Indole tolerance assays indicated that the amount of indole required to inhibit growth of most gut-protective bacteria was within the range detected in the CDI stools. We think that a high indole level limits the growth of beneficial indole-sensitive bacteria in the colon and alters colonization resistance and this might allow C. difficile to proliferate and persist. Together, these results reveal a unique mechanism of C. difficile persistence and provide insight into complex interactions and chemical warfare among the gut microbiota. IMPORTANCE Clostridium difficile infection is the leading cause of hospital-acquired and antibiotic-associated diarrhea worldwide. C. difficile flourishes in the colon after the diversity of the beneficial and protective gut microbiota have been altered by antibiotic therapy. C. difficile tends to persist, as does dysbiosis, encouraging recurrence a few days to weeks after treatment, and this further complicates treatment options. Here, we show that C. difficile might persist by manipulating the indigenous microbiota to produce indole, a bioactive molecule that inhibits the growth and reconstitution of the protective gut microbiota during infection. This discovery may explain a unique strategy C. difficile uses to control other bacteria in the colon and provide insight into the complex interactions and chemical warfare among the gut microbiota.
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Affiliation(s)
- Charles Darkoh
- University of Texas Health Science Center, School of Public Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, Center For Infectious Diseases, Houston, Texas, USA
- Microbiology and Infectious Diseases Program, UTHealth Graduate School of Biomedical Sciences, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Kimberly Plants-Paris
- University of Texas Health Science Center, School of Public Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, Center For Infectious Diseases, Houston, Texas, USA
| | - Dayna Bishoff
- University of Texas Health Science Center, School of Public Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, Center For Infectious Diseases, Houston, Texas, USA
| | - Herbert L. DuPont
- University of Texas Health Science Center, School of Public Health, Department of Epidemiology, Human Genetics, and Environmental Sciences, Center For Infectious Diseases, Houston, Texas, USA
- Microbiology and Infectious Diseases Program, UTHealth Graduate School of Biomedical Sciences, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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A rapid method for post-antibiotic bacterial susceptibility testing. PLoS One 2019; 14:e0210534. [PMID: 30629681 PMCID: PMC6328127 DOI: 10.1371/journal.pone.0210534] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/26/2018] [Indexed: 11/19/2022] Open
Abstract
Antibiotic susceptibility testing is often performed to determine the most effective antibiotic treatment for a bacterial infection, or perhaps to determine if a particular strain of bacteria is becoming drug resistant. Such tests, and others used to determine efficacy of candidate antibiotics during the drug discovery process, have resulted in a demand for more rapid susceptibility testing methods. Here, we have developed a susceptibility test that utilizes chemiluminescent determination of ATP release from bacteria and the overall optical density (OD600) of the bacterial solution. Bacteria release ATP during a growth phase or when they are lysed in the presence of an effective antibiotic. Because optical density increases during growth phase, but does not change during bacterial lysing, an increase in the ATP:optical density ratio after the bacteria have reached the log phase of growth (which is steady) would indicate antibiotic efficacy. Specifically, after allowing a kanamycin-resistant strain of Escherichia coli (E.coli) to pass through the growth phase and reach steady state, the addition of levofloxacin, an antibiotic to which E. coli is susceptible, resulted in a significant increase in the ATP:OD600 ratio in comparison to the use of kanamycin alone (1.80 +/- 0.50 vs. 1.12 +/- 0.28). This difference could be measured 20 minutes after the addition of the antibiotic, to which the bacteria are susceptible, to the bacterial sample. Furthermore, this method also proved useful with gram positive bacteria, as the addition of kanamycin to a chloramphenicol-resistant strain of Bacillus subtilis (B. subtilis) resulted in an ATP:OD600 ratio of 2.14 +/- 0.26 in comparison to 0.62 +/- 0.05 for bacteria not subjected to the antibiotic to which the bacteria are susceptible. Collectively, these results suggest that measurement of the ATP:OD600 ratio may provide a susceptibility test for antibiotic efficacy that is more rapid and quantitative than currently accepted techniques.
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Comparison of E Test and Disc Diffusion Methods for Susceptibility Testing of Filamentous Fungi; Experience of a Routine Lab. ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2018. [DOI: 10.5812/archcid.57889] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Nyandwi J, Manirakiza S, Ndirahisha E, Ngomirakiza JB, Nisubire D, Nduwayo E, Bukuru H. Frequency of Uropathogens and Antimicrobial Susceptibility in Childhood Urinary Tract Infection at Kamenge University Hospital, Bujumbura, Burundi. East Afr Health Res J 2017; 1:47-52. [PMID: 34308158 PMCID: PMC8279265 DOI: 10.24248/eahrj-d-16-00331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/05/2017] [Indexed: 11/20/2022] Open
Abstract
Background Increasing resistance to antimicrobials is a worldwide problem. The aim of our study was to determine the pathogens and antimicrobial susceptibility of bacteria causing urinary tract infection (UTI) in children. Methods This is a prospective cohort study conducted over a 10-month period with 101 children hospitalised at Kamenge University Hospital for acute UTI. The infections were confirmed by Kass urinalysis criteria, and culture and susceptibility antibiotic tests were performed for isolated microbial agents. Results Frequency of UTI in the overall population of children hospitalised at Kamange University Hospital was 8.4%. Of the 101 children with UTIs, 87 (86.1%) were under the age of 24 months. Diagnosis of pyelonephritis (82%) was the most common, followed by cystitis (18%). Escherichia coli (82%) was the most frequent pathogen causing UTI. We found E coli and Klebsiella pneumonia to be resistant to aminopenicillins (100%), cotrimoxazole (98.2%, 100%), Augmentin (amoxicillin/clavulanic acid) (70.5%, 80%), cefotaxime (45.8%, 28.6%), cefuroxime (36.8 to 45.5%, 50%), fluoroquinolones (33.3 to 53.6%, 28.6 to 50%), gentamicin (27.5%, 20%), and nitrofurantoin (9.3%, 50%). Conclusion E coli is the main causal agent of UTI in childhood with a high resistance to antibiotics. Appropriate antibiotics for empiric therapy should be based on local circulating bacterial strains and resistance profiles.
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Affiliation(s)
- Joseph Nyandwi
- Département de Médecine Interne, Le Centre Hospitalo-Universitaire de Kamenge, Bujumbura, Burundi.,Unité d'Hémodialyse, Burundi Kidney Care Clinic, Bujumbura, Burundi
| | - Sébastien Manirakiza
- Département d'Imagerie Médicale, Le Centre Hospitalo-Universitaire de Kamenge, Bujumbura, Burundi
| | - Eugàne Ndirahisha
- Département de Médecine Interne, Le Centre Hospitalo-Universitaire de Kamenge, Bujumbura, Burundi
| | | | - Désiré Nisubire
- Département des Laboratoires, Le Centre Hospitalo-Universitaire de Kamenge, Bujumbura, Burundi
| | - Emmanuel Nduwayo
- Département de Médecine Interne, Le Centre Hospitalo-Universitaire de Kamenge, Bujumbura, Burundi
| | - Hélàne Bukuru
- Département de Pédiatrie, Le Centre Hospitalo-Universitaire de Kamenge, Bujumbura, Burundi
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Pharmacodynamics of Voriconazole against Wild-Type and Azole-Resistant Aspergillus flavus Isolates in a Nonneutropenic Murine Model of Disseminated Aspergillosis. Antimicrob Agents Chemother 2016; 61:AAC.01491-16. [PMID: 27821453 DOI: 10.1128/aac.01491-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/01/2016] [Indexed: 11/20/2022] Open
Abstract
Invasive aspergillosis (IA) due to Aspergillus flavus is associated with high mortality. Although voriconazole (VRC) is widely recommended as the first-line treatment for IA, emergence of azole resistance in Aspergillus spp. is translating to treatment failure. We evaluated the efficacy of voriconazole in a nonneutropenic murine model of disseminated A. flavus infection using two voriconazole-resistant isolates (one harboring the Y319H substitution in the cyp51C gene) and two wild-type isolates without mutations. All isolates exhibited a dose-response relationship, and voriconazole treatment improved mouse survival in a dose-dependent manner. At 40 mg/kg of body weight, 100% efficacy was observed for 1 susceptible isolate and 1 resistant isolate (with mutation), whereas for another susceptible isolate and resistant isolate (without mutation), survival rates were 81% and 72%, respectively. The Hill equation with a variable slope fitted the relationship between the area under the concentration-time curve (AUC)/MIC ratio and 14-day survival well for each strain. An F test showed the 50% effective doses to be significantly different from each other (P = 0.0023). However, contrary to expectation, there was a significant difference in exposure-response relationships between strains, and it appeared that the susceptible strains required a relatively higher exposure than the resistant ones to result in the same treatment effect, the 50% effective pharmacokinetic/pharmacodynamic (PK/PD) index (EI50) required being negatively and log-linearly related to the MIC (P = 0.04). We conclude that the efficacy of voriconazole depended on drug exposure and the voriconazole MIC of the isolates, but lower exposures are required for strains with higher MICs. These findings may have profound significance in clinical practice with respect to dosing and drug choice.
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14
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Balouiri M, Sadiki M, Ibnsouda SK. Methods for in vitro evaluating antimicrobial activity: A review. J Pharm Anal 2016; 6:71-79. [PMID: 29403965 PMCID: PMC5762448 DOI: 10.1016/j.jpha.2015.11.005] [Citation(s) in RCA: 2518] [Impact Index Per Article: 314.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 11/21/2015] [Accepted: 11/23/2015] [Indexed: 11/21/2022] Open
Abstract
In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. Therefore, a greater attention has been paid to antimicrobial activity screening and evaluating methods. Several bioassays such as disk-diffusion, well diffusion and broth or agar dilution are well known and commonly used, but others such as flow cytofluorometric and bioluminescent methods are not widely used because they require specified equipment and further evaluation for reproducibility and standardization, even if they can provide rapid results of the antimicrobial agent's effects and a better understanding of their impact on the viability and cell damage inflicted to the tested microorganism. In this review article, an exhaustive list of in vitro antimicrobial susceptibility testing methods and detailed information on their advantages and limitations are reported.
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Affiliation(s)
- Mounyr Balouiri
- Laboratory of Microbial Biotechnology, Faculty of Sciences and Techniques, University Sidi Mohamed Ben Abdellah, B.P. 2202 Imouzzer Road, Fez, Morocco
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15
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Alastruey-Izquierdo A, Melhem MSC, Bonfietti LX, Rodriguez-Tudela JL. SUSCEPTIBILITY TEST FOR FUNGI: CLINICAL AND LABORATORIAL CORRELATIONS IN MEDICAL MYCOLOGY. Rev Inst Med Trop Sao Paulo 2016; 57 Suppl 19:57-64. [PMID: 26465371 PMCID: PMC4711191 DOI: 10.1590/s0036-46652015000700011] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During recent decades, antifungal susceptibility testing has become standardized and nowadays has the same role of the antibacterial susceptibility testing in microbiology laboratories. American and European standards have been developed, as well as equivalent commercial systems which are more appropriate for clinical laboratories. The detection of resistant strains by means of these systems has allowed the study and understanding of the molecular basis and the mechanisms of resistance of fungal species to antifungal agents. In addition, many studies on the correlation of in vitro results with the outcome of patients have been performed, reaching the conclusion that infections caused by resistant strains have worse outcome than those caused by susceptible fungal isolates. These studies have allowed the development of interpretative breakpoints for Candida spp. and Aspergillus spp., the most frequent agents of fungal infections in the world. In summary, antifungal susceptibility tests have become essential tools to guide the treatment of fungal diseases, to know the local and global disease epidemiology, and to identify resistance to antifungals.
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16
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Kumar D, Bhattacharyya S, Gupta P, Banerjee G, Singh M. Comparative Analysis of Disc Diffusion and E-test with Broth Micro-dilution for Susceptibility Testing of Clinical Candida Isolates Against Amphotericin B, Fluconazole, Voriconazole and Caspofungin. J Clin Diagn Res 2015; 9:DC01-4. [PMID: 26675415 DOI: 10.7860/jcdr/2015/14119.6735] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/05/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Antifungal susceptibility testing remains an area of intense interest because of the increasing number of clinical isolates resistant to antifungal therapy. Clinical and Laboratory Standards Institute has proposed reference broth micro dilution (BMD) method for susceptibility testing. The reference method is time-consuming and poorly suited for the routine clinical laboratory setting. Agar-based susceptibility testing methods, disk diffusion (DD) method and the E-test method can be an easier, reliable and less time consuming alternative for the BMD method. AIM To compare the results of Amphotericin B, fluconazole, voriconazole, and Caspofungin susceptibility testing by DD, and the E-test method with the CLSI reference method for clinical Candida isolates. MATERIALS AND METHODS Broth Microdilution (BMD), E-test and Disk diffusion testing of the various clinical Candida isolates was performed in accordance with CLSI documents. The results obtained were analysed and compared. RESULTS The categorical agreement for Amphotericin B, fluconazole, voriconazole, and Caspofungin susceptibility results by E-test and DD method was 65.2%, 67.4%; 100%, 82.6%; 100%, 100%; 100%, 97.8% respectively. CONCLUSION The agar-based E-test and disk diffusion methods are reliable alternatives to the BMD method for Candida isolates when test susceptible to fluconazole, voriconazole, and Caspofungin, however the susceptibility testing results must be interpreted with caution in case of Amphotericin B.
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Affiliation(s)
- Deepak Kumar
- Assistant Professor, Department of Microbiology, IMS, BHU Varanasi, U.P., India
| | | | - Prashant Gupta
- Assistant Professor, Department of Microbiology, King George's Medical University , Lucknow, India
| | - Gopa Banerjee
- Professor, Department of Microbiology, King George's Medical University , Lucknow, India
| | - Mastan Singh
- Professor and HOD, Department of Microbiology, King George's Medical University , Lucknow, India
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