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Vijay S, Bao NLH, Vinh DN, Nhat LTH, Thu DDA, Quang NL, Trieu LPT, Nhung HN, Ha VTN, Thai PVK, Ha DTM, Lan NH, Caws M, Thwaites GE, Javid B, Thuong NTT. Rifampicin tolerance and growth fitness among isoniazid-resistant clinical Mycobacterium tuberculosis isolates: an in-vitro longitudinal study. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.22.568240. [PMID: 38045287 PMCID: PMC10690245 DOI: 10.1101/2023.11.22.568240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Antibiotic tolerance in Mycobacterium tuberculosis leads to less effective bacterial killing, poor treatment responses and resistant emergence. Therefore, we investigated the rifampicin tolerance of M. tuberculosis isolates, with or without pre-existing isoniazid-resistance. We determined the in-vitro rifampicin survival fraction by minimum duration of killing assay in isoniazid susceptible (IS, n=119) and resistant (IR, n=84) M. tuberculosis isolates. Then we correlated the rifampicin tolerance with bacterial growth, rifampicin minimum inhibitory concentrations (MICs) and isoniazid-resistant mutations. The longitudinal IR isolates collected from patients were analyzed for changes in rifampicin tolerance and associated emergence of genetic variants. The median duration of rifampicin exposure reducing the M. tuberculosis surviving fraction by 90% (minimum duration of killing-MDK90) increased from 1.23 (95%CI 1.11; 1.37) and 1.31 (95%CI 1.14; 1.48) to 2.55 (95%CI 2.04; 2.97) and 1.98 (95%CI 1.69; 2.56) days, for IS and IR respectively, during 15 to 60 days of incubation. This indicated the presence of fast and slow growing tolerant sub-populations. A range of 6 log 10 -fold survival fraction enabled classification of tolerance as low, medium or high and revealed IR association with increased tolerance with faster growth (OR=2.68 for low vs. medium, OR=4.42 for low vs. high, P -trend=0.0003). The high tolerance in IR isolates was specific to those collected during rifampicin treatment in patients and associated with bacterial genetic microvariants. Furthermore, the high rifampicin tolerant IR isolates have survival potential similar to multi-drug resistant isolates. These findings suggest that IR tuberculosis needs to be evaluated for high rifampicin tolerance to improve treatment regimen and prevent the risk of MDR-TB emergence.
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2
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Sohani Z, Zhao N, Weiss K, Knecht H. Anaplasmosis encephalitis and infection of non-myeloid bone marrow precursors. BMJ Case Rep 2023; 16:e254603. [PMID: 38035680 PMCID: PMC10689420 DOI: 10.1136/bcr-2023-254603] [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] [Indexed: 12/02/2023] Open
Abstract
Due to climate change, infections from tickborne pathogens are becoming more prevalent in the Northern Hemisphere. Human granulocytic anaplasmosis, caused by the obligate intracellular gram-negative bacteria Anaplasma phagocytophilum and carried by Ixodes ticks, can lead to morbidity and mortality in select populations. Anaplasmosis is commonly accompanied by significant cytopaenia, the pathophysiology of which remains unknown. Our case report describes an uncommon meningoencephalitic presentation of anaplasmosis with substantial anaemia and thrombocytopaenia. Additionally, we propose a mechanism of bone marrow infection and suppression by A. phagocytophilum which may be responsible for the cytopaenia in anaplasmosis and provide pictographic evidence of anaplasma in peripheral blood, cerebrospinal fluid and bone marrow.
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Affiliation(s)
- Zahra Sohani
- McGill University Health Centre, Montreal, Quebec, Canada
| | - Nan Zhao
- Department of Medicine, Jewish General Hospital, Montreal, Quebec, Canada
| | - Karl Weiss
- Department of Medicine, Jewish General Hospital, Montreal, Quebec, Canada
| | - Hans Knecht
- Department of Medicine, McGill University, Montreal, Quebec, Canada
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3
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Farooq I, Moriarty TJ. The Impact of Tick-Borne Diseases on the Bone. Microorganisms 2021; 9:663. [PMID: 33806785 PMCID: PMC8005031 DOI: 10.3390/microorganisms9030663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 12/21/2022] Open
Abstract
Tick-borne infectious diseases can affect many tissues and organs including bone, one of the most multifunctional structures in the human body. There is a scarcity of data regarding the impact of tick-borne pathogens on bone. The aim of this review was to survey existing research literature on this topic. The search was performed using PubMed and Google Scholar search engines. From our search, we were able to find evidence of eight tick-borne diseases (Anaplasmosis, Ehrlichiosis, Babesiosis, Lyme disease, Bourbon virus disease, Colorado tick fever disease, Tick-borne encephalitis, and Crimean-Congo hemorrhagic fever) affecting the bone. Pathological bone effects most commonly associated with tick-borne infections were disruption of bone marrow function and bone loss. Most research to date on the effects of tick-borne pathogen infections on bone has been quite preliminary. Further investigation of this topic is warranted.
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Affiliation(s)
- Imran Farooq
- Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, Canada;
| | - Tara J. Moriarty
- Faculty of Dentistry, University of Toronto, Toronto, ON M5G 1G6, Canada;
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, ON M5G 1G6, Canada
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4
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Klompas AM, Boswell MR, Plack DL, Smith MM. Thrombocytopenia: Perioperative Considerations for Patients Undergoing Cardiac Surgery. J Cardiothorac Vasc Anesth 2021; 36:893-905. [PMID: 33707107 DOI: 10.1053/j.jvca.2021.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 11/11/2022]
Abstract
The etiologies of thrombocytopenia in patients presenting for cardiac surgery are extensive, but clinically relevant conditions generally can be categorized by those related to decreased platelet production or increased platelet destruction. Many causes require mere acknowledgment and availability of allogeneic platelet transfusion; others have unique considerations for which providers should be familiar. The purpose of this review is to provide an overview of the common causes of thrombocytopenia, summarize the literature, and discuss perioperative considerations for patients undergoing cardiac surgery.
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Affiliation(s)
- Allan M Klompas
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine and Science, 200 First St SW, Rochester, MN
| | - Michael R Boswell
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine and Science, 200 First St SW, Rochester, MN
| | - Daniel L Plack
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine and Science, 200 First St SW, Rochester, MN
| | - Mark M Smith
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic College of Medicine and Science, 200 First St SW, Rochester, MN.
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5
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Katsogiannou EG, Katsoulos PD, Christodoulopoulos G, Polizopoulou ZS, Papadakis SM, Kokkinaki KC, Billinis C, Boutsini S, Stougiou D, Athanasiou LV. Quantitative and Morphological Blood Cell Findings Associated with the Presence of Antigen and/or Antibodies Against Anaplasma phagocytophilum in Sheep. Vector Borne Zoonotic Dis 2021; 21:321-329. [PMID: 33493073 DOI: 10.1089/vbz.2020.2719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Anaplasma phagocytophilum is the causative agent of a disease known as tick borne fever in sheep, although fever is not always present. Due to inconclusive clinical signs, diagnosis is based on the cytological or molecular detection of the microorganism in blood and/or the determination of antibodies against A. phagocytophilum. The aim of the study was to determine the alterations caused by the presence of antibodies and/or the antigen of A. phagocytophilum in the blood cell count and morphology in sheep. Cytology and indirect immunofluorescence assay were performed for detection of antibodies and the antigen of A. phagocytophilum, respectively. The samples were divided into four groups depending on the result of the antigen and antibody detection. The samples that were only positive for antigen detection had mild anemia, leukopenia (lymphopenia), and thrombocytopenia. The samples that were positive in both assays had anemia, leukopenia (neutropenia and lymphopenia), and thrombocytopenia. Samples that were positive only for antibody detection had mild leukopenia. Morphological findings in infected sheep included band neutrophils, toxic neutrophils, reactive lymphocytes, and activated monocytes. The hematological findings along with cytological and serological tests can contribute to the assessment of the stage of the disease. A combination of leukopenia and thrombocytopenia raises a strong suspicion of the disease. When the microorganism and antibodies are simultaneously present, sheep are more susceptible to secondary complications. The first reported morphological findings and the quantitative hematological alterations are indicative of an inflammatory reaction, antigenic stimulation, and stress.
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Affiliation(s)
- Eleni G Katsogiannou
- Department of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Panagiotis Dimitrios Katsoulos
- Clinic of Farm Animals, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Georgios Christodoulopoulos
- Department of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Zoe S Polizopoulou
- Diagnostic Laboratory, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Stavros M Papadakis
- Department of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Kassiopi Christina Kokkinaki
- Department of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Charalambos Billinis
- Laboratory of Microbiology and Parasitology, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
| | - Sofia Boutsini
- National Reference Laboratory for Parasites, Directory of Veterinary Centre of Athens, Ministry of Rural Development and Food, Athens, Greece
| | - Despoina Stougiou
- National Reference Laboratory for Parasites, Directory of Veterinary Centre of Athens, Ministry of Rural Development and Food, Athens, Greece
| | - Labrini V Athanasiou
- Department of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, Karditsa, Greece
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6
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Huerga H, Sanchez-Padilla E, Melikyan N, Atshemyan H, Hayrapetyan A, Ulumyan A, Bastard M, Khachatryan N, Hewison C, Varaine F, Bonnet M. High prevalence of infection and low incidence of disease in child contacts of patients with drug-resistant tuberculosis: a prospective cohort study. Arch Dis Child 2019; 104:622-628. [PMID: 30523172 PMCID: PMC6589461 DOI: 10.1136/archdischild-2018-315411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We aimed to measure the prevalence and incidence of latent tuberculosis infection (LTBI) and tuberculosis (TB) disease in children in close contact with patients with drug-resistant TB (DR-TB) in a country with high DR-TB prevalence. DESIGN AND SETTING This is a prospective cohort study of paediatric contacts of adult patients with pulmonary DR-TB in Armenia. Children were screened using tuberculin skin test, interferon-gamma release assay and chest X-ray at the initial consultation, and were reassessed every 3-6 months for a period of 24 months. Children did not receive preventive treatment. MAIN OUTCOME MEASURES Prevalence and incidence of LTBI and TB disease; factors associated with prevalent LTBI. RESULTS At initial evaluation, 3 of the 150 children included were diagnosed with TB disease (2.0%). The prevalence of LTBI was 58.7%. The incidence of LTBI was 19.9 per 100 children per year, and was especially high during the first 6 months of follow-up (33.3 per 100 children per year). No additional cases with incident disease were diagnosed during follow-up. After adjustment, prevalent LTBI was significantly associated with the child's age, sleeping in the same house, higher household density, the index case's age, positive smear result and presence of lung cavities. CONCLUSIONS Children in close contact with patients with DR-TB or in contact with very contagious patients had an increased risk of prevalent LTBI. Although none of the children developed TB disease during a 2-year follow-up period, screening for symptoms of TB disease, based on the prevalence of disease at recruitment, together with follow-up and repeated testing of non-infected contacts, is highly recommended in paediatric contacts of patients with DR-TB.
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Affiliation(s)
| | | | | | | | | | - Ani Ulumyan
- National TB Center in Abovyan, Yerevan, Armenia
| | | | | | | | | | - Maryline Bonnet
- Epicentre, Paris, France,IRD UMI233/University of Montpellier/INSRERM U175, Montpellier, France
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7
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Loo EXL, Chew LJM, Zulkifli AB, Ta LDH, Kuo IC, Goh A, Teoh OH, Van Bever H, Gluckman PD, Yap F, Tan KH, Chong YS, Lee BW, Shek LPC. Comparison of microbiota and allergen profile in house dust from homes of allergic and non-allergic subjects- results from the GUSTO study. World Allergy Organ J 2018; 11:37. [PMID: 30534340 PMCID: PMC6280478 DOI: 10.1186/s40413-018-0212-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/04/2018] [Indexed: 02/08/2023] Open
Abstract
Background The prevalence of allergic diseases, such as asthma, allergic rhinitis, eczema and food allergy, has been increasing worldwide, as shown in a large number of studies, including the International Study of Asthma and Allergies in Childhood (ISAAC). However, there is significant variation in the prevalence of these diseases in different regions, suggesting that there may be location-specific factors such as environment and microbial exposure affecting allergic disease prevalence. Hence, in this study we determine if there is a difference in microbiota composition and allergen concentration of household dust collected from the homes of non-allergic and allergic subjects from the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort. Methods From the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) cohort, 25 allergic subjects and 25 non-allergic subjects were selected at the year 5.5 follow up. Definitions of allergic outcomes were standardized in the questionnaires administered at 3, 6, 9, 12, 15, 18, 24, 36, 48 and 60 months to ensure consistency during interviews and home visits. Allergen sensitization was determined by skin prick testing (SPT) at 18, 36 and 60 months. Dust samples were collected from the subject’s bed, sofa, and play area. DNA extraction was carried out and V3-V4 hypervariable regions of bacterial 16S rRNA gene were sequenced. Protein extraction was performed and allergens assayed by using multiplex assay and ELISA. Results The most abundant phyla in house dust were Actinobacteria (29.8%), Firmicutes (27.7%), and Proteobacteria (22.4%). Although there were no differences in bacteria abundance and diversity between house dust samples of allergic and non-allergic subjects, the relative abundance of Anaplasmataceae, Bacteroidaceae, and Leptospiraceae were significantly higher in dust samples of allergic subjects as compared to non-allergic subjects in 2 or more locations. The concentration of Der p 1 was significantly lower in bed dust samples of allergic subjects (Median [Interquartile range], 174 ng/g [115–299 ng/g]) as compared to non-allergic subjects (309 ng/g [201–400 ng/g]; P < 0.05). The concentration of tropomyosin was significantly higher in sofa dust samples of allergic subjects (175 ng/g [145–284 ng/g] as compared to non-allergic subjects (116 ng/g [52.8–170 ng/g]; P < 0.05). Conclusion In conclusion, we found a differential microbiota and allergen profile between homes of allergic and non-allergic subjects. Trial registration NCT01174875 Registered 1 July 2010, retrospectively registered. Electronic supplementary material The online version of this article (10.1186/s40413-018-0212-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Evelyn Xiu Ling Loo
- 1Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Lamony Jian Ming Chew
- 2Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Atiqa Binte Zulkifli
- 2Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Le Duc Huy Ta
- 2Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - I-Chun Kuo
- 2Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Anne Goh
- 3Allergy Service, Department of Paediatrics, KK Women's and Children's Hospital, Singapore, Singapore
| | - Oon Hoe Teoh
- 10Respiratory Medicine Service, Department of Paediatrics, KK Women's and Children's Hospital, Singapore, Singapore
| | - Hugo Van Bever
- 2Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,7Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore, Singapore
| | - Peter D Gluckman
- 5Growth, Development and Metabolism Programme, Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,6Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Fabian Yap
- 9Department of Endocrinology, KK Women's and Children's Hospital, Singapore, Singapore
| | - Kok Hian Tan
- 8Department of Maternal Fetal Medicine, KK Women's and Children's Hospital, Singapore, Singapore
| | - Yap Seng Chong
- 1Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,4Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Bee Wah Lee
- 2Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Lynette Pei-Chi Shek
- 1Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,2Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,7Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, National University Health System, Singapore, Singapore
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8
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The Simplest Explanation: Pancytopenia. Am J Med 2018; 131:1052-1054. [PMID: 29649461 DOI: 10.1016/j.amjmed.2018.03.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 11/21/2022]
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9
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Kodama C, Lange B, Olaru ID, Khan P, Lipman M, Seddon JA, Sloan D, Grandjean L, Ferrand RA, Kranzer K. Mycobacterium tuberculosis transmission from patients with drug-resistant compared to drug-susceptible TB: a systematic review and meta-analysis. Eur Respir J 2017; 50:50/4/1701044. [PMID: 29074544 DOI: 10.1183/13993003.01044-2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 08/03/2017] [Indexed: 01/27/2023]
Affiliation(s)
- Chiori Kodama
- Dept of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,These authors contributed equally
| | - Berit Lange
- Division of Infectious Diseases, Dept of Medicine II, Medical Center - Faculty of Medicine, University of Freiburg, Freiburg, Germany .,Centre for Chronic Immunodeficiency, Medical Center - Faculty of Medicine, University of Freiburg, Freiburg, Germany.,These authors contributed equally
| | - Ioana D Olaru
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany
| | - Palwasha Khan
- Dept of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Marc Lipman
- Royal Free London NHS Foundation Trust and UCL Respiratory, Division of Medicine, University College London, London, UK
| | - James A Seddon
- Centre for International Child Health, Dept of Paediatrics, Imperial College London, London, UK
| | - Derek Sloan
- School of Medicine, University of St Andrews, Fife, UK
| | - Louis Grandjean
- Dept of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Rashida Abbas Ferrand
- Dept of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK.,Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Katharina Kranzer
- Dept of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,National and Supranational Reference Laboratory, Leibnitz Research Centre, Borstel, Germany
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10
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Khanal S, Sultana H, Catravas JD, Carlyon JA, Neelakanta G. Anaplasma phagocytophilum infection modulates expression of megakaryocyte cell cycle genes through phosphatidylinositol-3-kinase signaling. PLoS One 2017; 12:e0182898. [PMID: 28797056 PMCID: PMC5552339 DOI: 10.1371/journal.pone.0182898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/20/2017] [Indexed: 12/19/2022] Open
Abstract
Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis infects neutrophils and other cells from hematopoietic origin. Using human megakaryocytic cell line, MEG-01, we show that expression of cell cycle genes in these cells are altered upon A. phagocytophilum infection. Expression of several cell cycle genes in MEG-01 cells was significantly up regulated at early and then down regulated at later stages of A. phagocytophilum infection. Lactate dehydrogenase (LDH) assays revealed reduced cellular cytotoxicity in MEG-01 cells upon A. phagocytophilum infection. The levels of both PI3KCA (p110 alpha, catalytic subunit) and PI3KR1 (p85, regulatory subunit) of Class I PI3 kinases and phosphorylated protein kinase B (Akt/PKB) and inhibitory kappa B (IκB) were elevated at both early and late stages of A. phagocytophilum infection. Inhibition of PI3 kinases with LY294002 treatment resulted in significant reduction in the expression of tested cell cycle genes, A. phagocytophilum burden and phosphorylated Akt levels in these MEG-01 cells. Collectively, these results suggest a role for PI3K-Akt-NF-κB signaling pathway in the modulation of megakaryocyte cell cycle genes upon A. phagocytophilum infection.
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Affiliation(s)
- Supreet Khanal
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, United States of America
| | - Hameeda Sultana
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, United States of America
- Center for Molecular Medicine, College of Sciences, Old Dominion University, Norfolk, VA, United States of America
| | - John D. Catravas
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States of America
- School of Medical Diagnostic and Translational Sciences, College of Health Sciences, Old Dominion University, Norfolk, VA, United States of America
| | - Jason A. Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, VA, United States of America
| | - Girish Neelakanta
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, United States of America
- Center for Molecular Medicine, College of Sciences, Old Dominion University, Norfolk, VA, United States of America
- * E-mail:
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11
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Pritt BS, Allerdice MEJ, Sloan LM, Paddock CD, Munderloh UG, Rikihisa Y, Tajima T, Paskewitz SM, Neitzel DF, Hoang Johnson DK, Schiffman E, Davis JP, Goldsmith CS, Nelson CM, Karpathy SE. Proposal to reclassify Ehrlichia muris as Ehrlichia muris subsp. muris subsp. nov. and description of Ehrlichia muris subsp. eauclairensis subsp. nov., a newly recognized tick-borne pathogen of humans. Int J Syst Evol Microbiol 2017; 67:2121-2126. [PMID: 28699575 DOI: 10.1099/ijsem.0.001896] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have previously described a novel taxon of the genus Ehrlichia (type strain WisconsinT), closely related to Ehrlichia muris, that causes human ehrlichiosis among patients with exposures to ticks in the upper midwestern USA. DNA from this bacterium was also detected in Ixodes scapularis and Peromyscus leucopus collected in Minnesota and Wisconsin. To determine the relationship between the E. muris-like agent (EMLA) and other species of the genus Ehrlichia phenotypic, genotypic and epidemiologic comparisons were undertaken, including sequence analysis of eight gene loci (3906 nucleotides) for 39 EMLA DNA samples and the type strain of E. muris AS145T. Three loci were also sequenced from DNA of nine strains of E. muris from mouse spleens from Japan. All sequences from E. muris were distinct from homologous EMLA sequences, but differences between them were less than those observed among other species of the genus Ehrlichia. Phenotypic comparison of EMLA and E. muris revealed similar culture and electron microscopic characteristics, but important differences were noted in their geographic distribution, ecological associations and behavior in mouse models of infection. Based on these comparisons, we propose that type strain WisconsinT represents a novel subspecies, Ehrlichia murissubsp. eauclairensis,subsp. nov. This strain is available through the Centers for Disease Control and Prevention Rickettsial Isolate Reference Collection (CRIRC EMU002T) and through the Collection de Souches de l'Unité des Rickettsies (CSURP2883 T). The subspecies Ehrlichia murissubsp. muris subsp. nov. is automatically created and the type strain AS145T is also available through the same collections (CRIRC EMU001T, CSUR E2T). Included is an emended description of E. muris.
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Affiliation(s)
- Bobbi S Pritt
- Mayo Clinic, Department of Laboratory Medicine and Pathology, Division of Clinical Microbiology, Rochester, MN, USA
| | - Michelle E J Allerdice
- Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, Rickettsial Zoonoses Branch, Atlanta, GA, USA
| | - Lynne M Sloan
- Mayo Clinic, Department of Laboratory Medicine and Pathology, Division of Clinical Microbiology, Rochester, MN, USA
| | - Christopher D Paddock
- Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, Rickettsial Zoonoses Branch, Atlanta, GA, USA
| | | | | | | | - Susan M Paskewitz
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | | | | | | | | | - Cynthia S Goldsmith
- Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Infectious Diseases Pathology Branch, Atlanta, GA, USA
| | - Curtis M Nelson
- Department of Entomology, University of Minnesota, St. Paul, MN, USA
| | - Sandor E Karpathy
- Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, Rickettsial Zoonoses Branch, Atlanta, GA, USA
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12
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Meftahi N, Namouchi A, Mhenni B, Brandis G, Hughes D, Mardassi H. Evidence for the critical role of a secondary site rpoB mutation in the compensatory evolution and successful transmission of an MDR tuberculosis outbreak strain. J Antimicrob Chemother 2015; 71:324-32. [PMID: 26538504 DOI: 10.1093/jac/dkv345] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/24/2015] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND MDR Mycobacterium tuberculosis clinical strains that cause large outbreaks, particularly among HIV-negative patients, are likely to have undergone the most successful compensatory evolution. Hence, mutations secondary to the acquisition of drug resistance are worthy of consideration in these highly transmissible strains. Here, we assessed the role of a mutation within rpoB, rpoB V615M, secondary to the rifampicin resistance-conferring mutation rpoB S531L, which is associated with a major MDR tuberculosis outbreak strain that evolved in an HIV-negative context in northern Tunisia. METHODS Using BCG as a model organism, we engineered strains harbouring either the rpoB S531L mutation alone or the double mutation rpoB S531L, V615M. Individual and competitive in vitro growth assays were performed in order to assess the relative fitness of each BCG mutant. RESULTS The rpoB V615M mutation was found to be invariably associated with rpoB S531L. Structural analysis mapped rpoB V615M to the same bridge helix region as rpoB compensatory mutations previously described in Salmonella. Compared with the rpoB single-mutant BCG, the double mutant displayed improved growth characteristics and fitness rates equivalent to WT BCG. Strikingly, the rpoB double mutation conferred high-level resistance to rifampicin. CONCLUSIONS Here, we demonstrated the fitness compensatory role of a mutation within rpoB, secondary to the rifampicin resistance mutation rpoB S531L, which is characteristic of an MDR M. tuberculosis major outbreak strain. The finding that this secondary mutation concomitantly increased the resistance level to rifampicin argues for its significant contribution to the successful transmission of the MDR-TB strain.
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Affiliation(s)
- Nedra Meftahi
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Amine Namouchi
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Besma Mhenni
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Gerrit Brandis
- Department of Medical Biochemistry and Microbiology, Box 582 Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Diarmaid Hughes
- Department of Medical Biochemistry and Microbiology, Box 582 Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Helmi Mardassi
- Unit of Typing & Genetics of Mycobacteria, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
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Abstract
A 65-year-old female with a history of multiple tick bites presented with fever and pancytopenia. Intracytoplasmic rickettsial morulae were detected on peripheral smear and bone marrow biopsy specimens, and PCR amplified Ehrlichia ewingii DNA from both specimens. To our knowledge, this is the first report of E. ewingii infection of human bone marrow.
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