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Maurin M, Pondérand L, Hennebique A, Pelloux I, Boisset S, Caspar Y. Tularemia treatment: experimental and clinical data. Front Microbiol 2024; 14:1348323. [PMID: 38298538 PMCID: PMC10827922 DOI: 10.3389/fmicb.2023.1348323] [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: 12/02/2023] [Accepted: 12/31/2023] [Indexed: 02/02/2024] Open
Abstract
Tularemia is a zoonosis caused by the Gram negative, facultative intracellular bacterium Francisella tularensis. This disease has multiple clinical presentations according to the route of infection, the virulence of the infecting bacterial strain, and the underlying medical condition of infected persons. Systemic infections (e.g., pneumonic and typhoidal form) and complications are rare but may be life threatening. Most people suffer from local infection (e.g., skin ulcer, conjunctivitis, or pharyngitis) with regional lymphadenopathy, which evolve to suppuration in about 30% of patients and a chronic course of infection. Current treatment recommendations have been established to manage acute infections in the context of a biological threat and do not consider the great variability of clinical situations. This review summarizes literature data on antibiotic efficacy against F. tularensis in vitro, in animal models, and in humans. Empirical treatment with beta-lactams, most macrolides, or anti-tuberculosis agents is usually ineffective. The aminoglycosides gentamicin and streptomycin remain the gold standard for severe infections, and the fluoroquinolones and doxycycline for infections of mild severity, although current data indicate the former are usually more effective. However, the antibiotic treatments reported in the literature are highly variable in their composition and duration depending on the clinical manifestations, the age and health status of the patient, the presence of complications, and the evolution of the disease. Many patients received several antibiotics in combination or successively. Whatever the antibiotic treatment administered, variable but high rates of treatment failures and relapses are still observed, especially in patients treated more then 2-3 weeks after disease onset. In these patients, surgical treatment is often necessary for cure, including drainage or removal of suppurative lymph nodes or other infectious foci. It is currently difficult to establish therapeutic recommendations, particularly due to lack of comparative randomized studies. However, we have attempted to summarize current knowledge through proposals for improving tularemia treatment which will have to be discussed by a group of experts. A major factor in improving the prognosis of patients with tularemia is the early administration of appropriate treatment, which requires better medical knowledge and diagnostic strategy of this disease.
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Affiliation(s)
- Max Maurin
- Centre National de Référence Francisella tularensis, CHU Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Translational Innovation in Medicine and Complexity (TIMC), Centre National de la Recherche Scientifique (CNRS), Grenoble, France
| | - Léa Pondérand
- Centre National de Référence Francisella tularensis, CHU Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Commissariat à l’énergie atomique (CEA), CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Aurélie Hennebique
- Centre National de Référence Francisella tularensis, CHU Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Translational Innovation in Medicine and Complexity (TIMC), Centre National de la Recherche Scientifique (CNRS), Grenoble, France
| | - Isabelle Pelloux
- Centre National de Référence Francisella tularensis, CHU Grenoble Alpes, Grenoble, France
| | - Sandrine Boisset
- Centre National de Référence Francisella tularensis, CHU Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Commissariat à l’énergie atomique (CEA), CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Yvan Caspar
- Centre National de Référence Francisella tularensis, CHU Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Commissariat à l’énergie atomique (CEA), CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
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Immunomodulatory Effects of Macrolides Considering Evidence from Human and Veterinary Medicine. Microorganisms 2022; 10:microorganisms10122438. [PMID: 36557690 PMCID: PMC9784682 DOI: 10.3390/microorganisms10122438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/17/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
Macrolide antimicrobial agents have been in clinical use for more than 60 years in both human and veterinary medicine. The discovery of the non-antimicrobial properties of macrolides and the effect of immunomodulation of the inflammatory response has benefited patients with chronic airway diseases and impacted morbidity and mortality. This review examines the evidence of antimicrobial and non-antimicrobial properties of macrolides in human and veterinary medicine with a focus toward veterinary macrolides but including important and relevant evidence from the human literature. The complete story for these complex and important molecules is continuing to be written.
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Galecio JS, Escudero E, Corrales JC, García-Romero E, de la Fe C, Hernandis V, Marin P. Susceptibility of caprine mastitis pathogens to tildipirosin, gamithromycin, oxytetracycline, and danofloxacin: effect of serum on the in vitro potency of current macrolides. World J Microbiol Biotechnol 2022; 38:221. [PMID: 36097302 PMCID: PMC9468077 DOI: 10.1007/s11274-022-03407-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/29/2022] [Indexed: 11/26/2022]
Abstract
Mastitis is a significant disease in dairy ruminants, causing economic losses to the livestock industry and severe risks to public health. Antibiotic therapy is one of the most crucial practices to treat mastitis, although the susceptibility of caprine mastitis pathogens to current antibiotics has not been tested under standard or modified incubation conditions. This work evaluated the in vitro activity of tildipirosin, gamithromycin, oxytetracycline, and danofloxacin against caprine mastitis pathogens incubated following standard conditions of Clinical and Laboratory Standards Institute (CLSI) and deviation method by 25% supplementation with goat serum. Mycoplasma agalactiae, Escherichia coli, Staphylococcus aureus, Streptococcus spp., and coagulase-negative Staphylococci (CNS) were isolated from dairy goats with mastitis in Spain. Minimum inhibitory concentrations (MICs) were determined using the broth microdilution technique. The lowest MIC90 under standard conditions was obtained with danofloxacin for mastitis-causing pathogens. An exception was M. agalactiae, where danofloxacin and oxytetracycline obtained low values. However, after adding serum, gamithromycin showed the lowest MIC50 for S. aureus, Streptococcus spp., and CNS. The lowest MIC50 was obtained with all the antibiotics tested (< 0.125 µg/ml) against M. agalactiae. Supplementing with serum resulted in a significant variation in tildipirosin and gamithromycin MIC values for CNS, S. aureus, M. agalagtiae, and E. coli. In brief, the MIC for antibiotics used against mastitis should be determined under conditions closely resembling intramammary infections to obtain representative susceptibility patterns against mastitis pathogens. Caprine mastitis pathogens were broadly susceptible to danofloxacin under standard conditions. The potency of macrolides against caprine mastitis pathogens increases when serum is present in culture media.
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Affiliation(s)
- Juan Sebastian Galecio
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, 30100, Murcia, Spain.
- Escuela de Medicina Veterinaria, Colegio de Ciencias de La Salud, Universidad San Francisco de Quito, Campus Cumbayá, Quito, EC 170157, Ecuador.
| | - Elisa Escudero
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, 30100, Murcia, Spain
| | - Juan Carlos Corrales
- Ruminant Health Research Group, Department of Animal Health, Faculty of Veterinary Sciences, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, 30100, Murcia, Spain
| | - Edgar García-Romero
- Ruminant Health Research Group, Department of Animal Health, Faculty of Veterinary Sciences, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, 30100, Murcia, Spain
| | - Christian de la Fe
- Ruminant Health Research Group, Department of Animal Health, Faculty of Veterinary Sciences, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, 30100, Murcia, Spain
| | - Verónica Hernandis
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, 30100, Murcia, Spain
| | - Pedro Marin
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, 30100, Murcia, Spain.
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Namoju R, Ismail M, Golla VK, Bamini T, Akarapu TL, Baloju D. A Case of Acute Generalized Exanthematous Pustulosis by Cefixime with Oral Mucosal Involvement. Curr Drug Saf 2021; 15:236-239. [PMID: 32729426 DOI: 10.2174/1574886315999200729144555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 11/22/2022]
Abstract
Acute generalized exanthematous pustulosis (AGEP) is a rare severe cutaneous adverse reaction characterized by the development of numerous sterile and non-follicular pustules on an erythematous base with no or minimal mucous membrane involvement associated with fever and leucocytosis. Cefixime is a cephalosporin-type beta-lactam antibiotic commonly used for the management of several infections. The Cefixime-induced AGEP cases are known to be rare. Here, we present the case report of a 26-year old female who developed Cefixime-induced AGEP with mucosal membrane involvement. To the best of our knowledge, this is the first case to report the mucosal membrane involvement in Cefixime-induced AGEP. We are presenting this case report to draw the attention on the existence and plethora of symptoms of Cefixime-induced AGEP hoping that the clinicians will reckon these in their differential diagnosis and implement the appropriate management strategies for this rare adverse event in their clinical practice.
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Affiliation(s)
- Ramanachary Namoju
- Department of Pharmacology Pharmacy Practice, Bhaskar Pharmacy College, Jawaharlal Nehru Technical University, Hyderabad,
Telangana 500075, India,Department of Pharmacology, GITAM Deemed to be University, Vishakhapatnam, Andhra Pradesh, India
| | - Mohammed Ismail
- Department of Pharmacology Pharmacy Practice, Bhaskar Pharmacy College, Jawaharlal Nehru Technical University, Hyderabad,
Telangana 500075, India
| | - Vinay Kumar Golla
- Department of Pharmacology Pharmacy Practice, Bhaskar Pharmacy College, Jawaharlal Nehru Technical University, Hyderabad,
Telangana 500075, India
| | - Tejaswini Bamini
- Department of Pharmacology Pharmacy Practice, Bhaskar Pharmacy College, Jawaharlal Nehru Technical University, Hyderabad,
Telangana 500075, India
| | - Thanmaya Lakshmi Akarapu
- Department of Pharmacology Pharmacy Practice, Bhaskar Pharmacy College, Jawaharlal Nehru Technical University, Hyderabad,
Telangana 500075, India
| | - Deepika Baloju
- Patient Safety Pharmacovigilance Associate, Adverse Drug Reaction Monitoring Centre
– Pharmacovigilance Program of India, Department of Pharmacology, Bhaskar Medical College, Hyderabad, Telangana
500075, India
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5
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Type VI Secretion System and Its Effectors PdpC, PdpD, and OpiA Contribute to Francisella Virulence in Galleria mellonella Larvae. Infect Immun 2021; 89:e0057920. [PMID: 33875476 PMCID: PMC8208517 DOI: 10.1128/iai.00579-20] [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] [Indexed: 11/20/2022] Open
Abstract
Francisella tularensis causes the deadly zoonotic disease tularemia in humans and is able to infect a broad range of organisms including arthropods, which are thought to play a major role in Francisella transmission. However, while mammalian in vitro and in vivo infection models are widely used to investigate Francisella pathogenicity, a detailed characterization of the major Francisella virulence factor, a noncanonical type VI secretion system (T6SS), in an arthropod in vivo infection model is missing. Here, we use Galleria mellonella larvae to analyze the role of the Francisella T6SS and its corresponding effectors in F. tularensis subsp. novicida virulence. We report that G. mellonella larvae killing depends on the functional T6SS and infectious dose. In contrast to other mammalian in vivo infection models, even one of the T6SS effectors PdpC, PdpD, or OpiA is sufficient to kill G. mellonella larvae, while sheath recycling by ClpB is dispensable. We further demonstrate that treatment by polyethylene glycol (PEG) activates Francisella T6SS in liquid culture and that this is independent of the response regulator PmrA. PEG-activated IglC secretion is dependent on T6SS structural component PdpB but independent of putative effectors PdpC, PdpD, AnmK, OpiB1, OpiB2, and OpiB3. The results of larvae infection and secretion assay suggest that AnmK, a putative T6SS component with unknown function, interferes with OpiA-mediated toxicity but not with general T6SS activity. We establish that the easy-to-use G. mellonella larvae infection model provides new insights into the function of T6SS and pathogenesis of Francisella.
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6
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Kassinger SJ, van Hoek ML. Genetic Determinants of Antibiotic Resistance in Francisella. Front Microbiol 2021; 12:644855. [PMID: 34054749 PMCID: PMC8149597 DOI: 10.3389/fmicb.2021.644855] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/25/2021] [Indexed: 12/21/2022] Open
Abstract
Tularemia, caused by Francisella tularensis, is endemic to the northern hemisphere. This zoonotic organism has historically been developed into a biological weapon. For this Tier 1, Category A select agent, it is important to expand our understanding of its mechanisms of antibiotic resistance (AMR). Francisella is unlike many Gram-negative organisms in that it does not have significant plasmid mobility, and does not express AMR mechanisms on plasmids; thus plasmid-mediated resistance does not occur naturally. It is possible to artificially introduce plasmids with AMR markers for cloning and gene expression purposes. In this review, we survey both the experimental research on AMR in Francisella and bioinformatic databases which contain genomic and proteomic data. We explore both the genetic determinants of intrinsic AMR and naturally acquired or engineered antimicrobial resistance as well as phenotypic resistance in Francisella. Herein we survey resistance to beta-lactams, monobactams, carbapenems, aminoglycosides, tetracycline, polymyxins, macrolides, rifampin, fosmidomycin, and fluoroquinolones. We also highlight research about the phenotypic AMR difference between planktonic and biofilm Francisella. We discuss newly developed methods of testing antibiotics against Francisella which involve the intracellular nature of Francisella infection and may better reflect the eventual clinical outcomes for new antibiotic compounds. Understanding the genetically encoded determinants of AMR in Francisella is key to optimizing the treatment of patients and potentially developing new antimicrobials for this dangerous intracellular pathogen.
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Affiliation(s)
| | - Monique L. van Hoek
- School of Systems Biology, George Mason University, Manassas, VA, United States
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Zhong ZX, Cui ZH, Li XJ, Tang T, Zheng ZJ, Ni WN, Fang LX, Zhou YF, Yu Y, Liu YH, Liao XP, Sun J. Nitrofurantoin Combined With Amikacin: A Promising Alternative Strategy for Combating MDR Uropathogenic Escherichia coli. Front Cell Infect Microbiol 2020; 10:608547. [PMID: 33409159 PMCID: PMC7779487 DOI: 10.3389/fcimb.2020.608547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/20/2020] [Indexed: 01/09/2023] Open
Abstract
Urinary tract infections (UTI) are common infections that can be mild to life threatening. However, increased bacterial resistance and poor patient compliance rates have limited the effectiveness of conventional antibiotic therapies. Here, we investigated the relationship between nitrofurantoin and amikacin against 12 clinical MDR uropathogenic Escherichia coli (UPEC) strains both in vitro and in an experimental Galleria mellonella model. In vitro synergistic effects were observed in all 12 test strains by standard checkerboard and time-kill assays. Importantly, amikacin or nitrofurantoin at half of the clinical doses were not effective in the treatment of UPEC infections in the G. mellonella model but the combination therapy significantly increased G. mellonella survival from infections caused by all 12 study UPEC strains. Taken together, these results demonstrated synergy effects between nitrofurantoin and amikacin against MDR UPEC.
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Affiliation(s)
- Zi-Xing Zhong
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Ze-Hua Cui
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Xiao-Jie Li
- Department of Laboratory Medicine, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Tian Tang
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Zi-Jian Zheng
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Wei-Na Ni
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Liang-Xing Fang
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Yu-Feng Zhou
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Yang Yu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China
| | - Ya-Hong Liu
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Xiao-Ping Liao
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Jian Sun
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
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Vergis J, Malik SS, Pathak R, Kumar M, Ramanjaneya S, Kurkure NV, Barbuddhe SB, Rawool DB. Exploiting Lactoferricin (17-30) as a Potential Antimicrobial and Antibiofilm Candidate Against Multi-Drug-Resistant Enteroaggregative Escherichia coli. Front Microbiol 2020; 11:575917. [PMID: 33072040 PMCID: PMC7531601 DOI: 10.3389/fmicb.2020.575917] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/17/2020] [Indexed: 12/28/2022] Open
Abstract
The study evaluated the in vitro antimicrobial and antibiofilm efficacy of an antimicrobial peptide (AMP), lactoferricin (17–30) [Lfcin (17–30)], against biofilm-forming multi-drug-resistant (MDR) strains of enteroaggregative Escherichia coli (EAEC), and subsequently, the in vivo antimicrobial efficacy was assessed in a Galleria mellonella larval model. Initially, minimum inhibitory concentration (MIC; 32 μM), minimum bactericidal concentration (MBC; 32 μM), and minimum biofilm eradication concentration (MBEC; 32 μM) of Lfcin (17–30) were determined against MDR-EAEC field isolates (n = 3). Lfcin (17–30) was tested stable against high-end temperatures (70 and 90°C), physiological concentration of cationic salts (150 mM NaCl and 2 mM MgCl2), and proteases (proteinase-K and lysozyme). Further, at lower MIC, Lfcin (17–30) proved to be safe for sheep RBCs, secondary cell lines (HEp-2 and RAW 264.7), and beneficial gut lactobacilli. In the in vitro time-kill assay, Lfcin (17–30) inhibited the MDR-EAEC strains 3 h post-incubation, and the antibacterial effect was due to membrane permeation of Lfcin (17–30) in the inner and outer membranes of MDR-EAEC. Furthermore, in the in vivo experiments, G. mellonella larvae treated with Lfcin (17–30) exhibited an increased survival rate, lower MDR-EAEC counts (P < 0.001), mild to moderate histopathological changes, and enhanced immunomodulatory effect and were safe to larval cells when compared with infection control. Besides, Lfcin (17–30) proved to be an effective antibiofilm agent, as it inhibited and eradicated the preformed biofilm formed by MDR-EAEC strains in a significant (P < 0.05) manner both by microtiter plate assay and live/dead bacterial quantification-based confocal microscopy. We recommend further investigation of Lfcin (17–30) in an appropriate animal model before its application in target host against MDR-EAEC strains.
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Affiliation(s)
- Jess Vergis
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - Satyaveer Singh Malik
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - Richa Pathak
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - Manesh Kumar
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | - Sunitha Ramanjaneya
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, India
| | | | | | - Deepak Bhiwa Rawool
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, India.,ICAR-National Research Centre on Meat, Hyderabad, India
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Dean SN, Milton ME, Cavanagh J, van Hoek ML. Francisella novicida Two-Component System Response Regulator BfpR Modulates iglC Gene Expression, Antimicrobial Peptide Resistance, and Biofilm Production. Front Cell Infect Microbiol 2020; 10:82. [PMID: 32232010 PMCID: PMC7082314 DOI: 10.3389/fcimb.2020.00082] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 02/18/2020] [Indexed: 12/20/2022] Open
Abstract
Response regulators are a critical part of the two-component system of gene expression regulation in bacteria, transferring a signal from a sensor kinase into DNA binding activity resulting in alteration of gene expression. In this study, we investigated a previously uncharacterized response regulator in Francisella novicida, FTN_1452 that we have named BfpR (Biofilm-regulating Francisella protein Regulator, FTN_1452). In contrast to another Francisella response regulator, QseB/PmrA, BfpR appears to be a negative regulator of biofilm production, and also a positive regulator of antimicrobial peptide resistance in this bacterium. The protein was crystallized and X-ray crystallography studies produced a 1.8 Å structure of the BfpR N-terminal receiver domain revealing interesting insight into its potential interaction with the sensor kinase. Structural analysis of BfpR places it in the OmpR/PhoP family of bacterial response regulators along with WalR and ResD. Proteomic and transcriptomic analyses suggest that BfpR overexpression affects expression of the critical Francisella virulence factor iglC, as well as other proteins in the bacterium. We demonstrate that mutation of bfpR is associated with an antimicrobial peptide resistance phenotype, a phenotype also associated with other response regulators, for the human cathelicidin peptide LL-37 and a sheep antimicrobial peptide SMAP-29. F. novicida with mutated bfpR replicated better than WT in intracellular infection assays in human-derived macrophages suggesting that the down-regulation of iglC expression in bfpR mutant may enable this intracellular replication to occur. Response regulators have been shown to play important roles in the regulation of bacterial biofilm production. We demonstrate that F. novicida biofilm formation was highly increased in the bfpR mutant, corresponding to altered glycogen synthesis. Waxworm infection experiments suggest a role of BfpR as a negative modulator of iglC expression with de-repression by Mg2+. In this study, we find that the response regulator BfpR may be a negative regulator of biofilm formation, and a positive regulator of antimicrobial peptide resistance in F. novicida.
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Affiliation(s)
- Scott N Dean
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Morgan E Milton
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - John Cavanagh
- Department of Biochemistry and Molecular Biology, The Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - Monique L van Hoek
- National Center for Biodefense and Infectious Diseases, and School of Systems Biology, George Mason University, Manassas, VA, United States
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10
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Larva of greater wax moth Galleria mellonella is a suitable alternative host for the fish pathogen Francisella noatunensis subsp. orientalis. BMC Microbiol 2020; 20:8. [PMID: 31918661 PMCID: PMC6953311 DOI: 10.1186/s12866-020-1695-0] [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: 05/16/2019] [Accepted: 12/31/2019] [Indexed: 12/26/2022] Open
Abstract
Background Francisella noatunensis subsp. orientalis (Fno) is the etiological agent of francisellosis in cultured warm water fish, such as tilapia. Antibiotics are administered to treat the disease but a better understanding of Fno infection biology will inform improved treatment and prevention measures. However, studies with native hosts are costly and considerable benefits would derive from access to a practical alternative host. Here, larvae of Galleria mellonella were assessed for suitability to study Fno virulence. Results Larvae were killed by Fno in a dose-dependent manner but the insects could be rescued from lethal doses of bacteria by antibiotic therapy. Infection progression was assessed by histopathology (haematoxylin and eosin staining, Gram Twort and immunohistochemistry) and enumeration of bacteria recovered from the larval haemolymph on selective agar. Fno was phagocytosed and could survive intracellularly, which is consistent with observations in fish. Virulence of five Fno isolates showed strong agreement between G. mellonella and red Nile tilapia hosts. Conclusions This study shows that an alternative host, G. mellonella, can be applied to understand Fno infections, which will assist efforts to identify solutions to piscine francisellosis thus securing the livelihoods of tilapia farmers worldwide and ensuring the production of this important food source.
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11
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Johnsrud JJ, Smith CR, Bradsher RW. Serendipitous Treatment of Tularemia in Pregnancy. Open Forum Infect Dis 2019; 6:ofz413. [PMID: 31660371 PMCID: PMC6804751 DOI: 10.1093/ofid/ofz413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 09/16/2019] [Indexed: 12/02/2022] Open
Abstract
We present a young pregnant woman who developed ulceroglandular tularaemia following a bite wound from a kitten. She grew Francisella tularensis from the ulcer. While awaiting bacterial culture results and serology for Bartonella, she was treated with azithromycin, with resolution of fever and axillary tenderness. Treatment recommendations for tularemia are either gentamicin or doxycycline, both of which can be perilous to the fetus. A Centers for Disease Control and Prevention report on the macrolide susceptibility of North American isolates of this organism has been underappreciated. The unanticipated result from this patient may give another potential option for treatment of tularemia in pregnancy.
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Affiliation(s)
- Joyce J Johnsrud
- Division of Infectious Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | | | - Robert W Bradsher
- Division of Infectious Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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12
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Eklund BE, Mahdi O, Huntley JF, Collins E, Martin C, Horzempa J, Fisher NA. The orange spotted cockroach ( Blaptica dubia, Serville 1839) is a permissive experimental host for Francisella tularensis. PROCEEDINGS OF THE WEST VIRGINIA ACADEMY OF SCIENCE 2017; 89:34-47. [PMID: 29578544 PMCID: PMC5863744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Francisella tularensis is a zoonotic bacterial pathogen that causes severe disease in a wide range of host animals, including humans. Well-developed murine models of F. tularensis pathogenesis are available, but they do not meet the needs of all investigators. However, researchers are increasingly turning to insect host systems as a cost-effective alternative that allows greater increased experimental throughput without the regulatory requirements associated with the use of mammals in biomedical research. Unfortunately, the utility of previously-described insect hosts is limited because of temperature restriction, short lifespans, and concerns about the immunological status of insects mass-produced for other purposes. Here, we present a novel host species, the orange spotted (OS) cockroach (Blaptica dubia), that overcomes these limitations and is readily infected by F. tularensis. Intrahemocoel inoculation was accomplished using standard laboratory equipment and lethality was directly proportional to the number of bacteria injected. Progression of infection differed in insects housed at low and high temperatures and F. tularensis mutants lacking key virulence components were attenuated in OS cockroaches. Finally, antibiotics were delivered to infected OS cockroaches by systemic injection and controlled feeding; in the latter case, protection correlated with oral bioavailability in mammals. Collectively, these results demonstrate that this new host system provides investigators with a new tool capable of interrogating F. tularensis virulence and immune evasion in situations where mammalian models are not available or appropriate, such as undirected screens of large mutant libraries.
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Affiliation(s)
- Bridget E. Eklund
- Russel and Anna Duncan Undergraduate Research Program, College of Agriculture, Food Systems and Natural Resources, North Dakota State University, Fargo, ND
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND
| | - Osama Mahdi
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, ND
| | - Jason F. Huntley
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, OH
| | - Elliot Collins
- Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV
| | - Caleb Martin
- Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV
| | - Joseph Horzempa
- Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV
| | - Nathan A. Fisher
- Department of Public Health, North Dakota State University, Fargo, ND
- Drug Development Division, Southern Research, Frederick, MD
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Hoang KV, Adcox HE, Fitch JR, Gordon DM, Curry HM, Schlesinger LS, White P, Gunn JS. AR-13, a Celecoxib Derivative, Directly Kills Francisella In Vitro and Aids Clearance and Mouse Survival In Vivo. Front Microbiol 2017; 8:1695. [PMID: 28955308 PMCID: PMC5600997 DOI: 10.3389/fmicb.2017.01695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/23/2017] [Indexed: 12/15/2022] Open
Abstract
Francisella tularensis (F. tularensis) is the causative agent of tularemia and is classified as a Tier 1 select agent. No licensed vaccine is currently available in the United States and treatment of tularemia is confined to few antibiotics. In this study, we demonstrate that AR-13, a derivative of the cyclooxygenase-2 inhibitor celecoxib, exhibits direct in vitro bactericidal killing activity against Francisella including a type A strain of F. tularensis (SchuS4) and the live vaccine strain (LVS), as well as toward the intracellular proliferation of LVS in macrophages, without causing significant host cell toxicity. Identification of an AR-13-resistant isolate indicates that this compound has an intracellular target(s) and that efflux pumps can mediate AR-13 resistance. In the mouse model of tularemia, AR-13 treatment protected 50% of the mice from lethal LVS infection and prolonged survival time from a lethal dose of F. tularensis SchuS4. Combination of AR-13 with a sub-optimal dose of gentamicin protected 60% of F. tularensis SchuS4-infected mice from death. Taken together, these data support the translational potential of AR-13 as a lead compound for the further development of new anti-Francisella agents.
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Affiliation(s)
- Ky V Hoang
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - Haley E Adcox
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - James R Fitch
- The Institute for Genomic Medicine, Nationwide Children's Hospital, ColumbusOH, United States
| | - David M Gordon
- The Institute for Genomic Medicine, Nationwide Children's Hospital, ColumbusOH, United States
| | - Heather M Curry
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - Larry S Schlesinger
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
| | - Peter White
- The Institute for Genomic Medicine, Nationwide Children's Hospital, ColumbusOH, United States.,Department of Pediatrics, The Ohio State University College of Medicine, ColumbusOH, United States
| | - John S Gunn
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, ColumbusOH, United States
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14
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Barksdale SM, Hrifko EJ, van Hoek ML. Cathelicidin antimicrobial peptide from Alligator mississippiensis has antibacterial activity against multi-drug resistant Acinetobacter baumanii and Klebsiella pneumoniae. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 70:135-144. [PMID: 28089718 DOI: 10.1016/j.dci.2017.01.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 06/06/2023]
Abstract
Alligator mississippiensis (American alligator), a member of order Crocodilia, lives in bacteria-laden environments but is not often known to succumb to bacterial infections. Their serum has been shown to have antibacterial activity beyond that of human serum, and it is believed that this activity is partially due to cationic antimicrobial peptides (CAMPs). CAMPs are produced by many organisms as part of the innate immune system. CAMPs are attractive possible therapies against multi-drug resistant bacteria, such as those found in biofilm-infected war wounds, because they seldom cause genetic resistance in bacteria and are effective against antibiotic resistant bacteria. In this work, we identified, synthesized, and characterized a cathelicidin and two shorter fragments from the American alligator. We discovered the cathelicidin using Basic Local Alignment Search Tool (BLAST) alignment and by comparing A. mississippiensis expressed sequence tags (ESTs) with propeptide cathelicidins of other reptiles. We analyzed the structure using bioinformatics tools and circular dichroism and predicted that the full-length cathelicidin peptide has a mixed structure, with an N-terminal α-helix and a center Pro hinge. In minimal inhibitory concentration (MIC) assays, it was determined that the cathelicidin and the two shorter fragments have strong activity against multiple Gram-negative bacteria, including clinical isolates of multi-drug resistant (MDR) Acinetobacter baumannii and carbapenem-resistant Klebsiella pneumoniae. Using the ethidium bromide uptake assay, it was found that these peptides permeabilize the bacterial membrane and are less sensitive to salt inhibition than many other known CAMPs. The alligator cathelicidin peptides were not hemolytic against sheep red blood cells at 300 μg/ml and were not significantly cytotoxic against A549 human lung epithelial cells after 24 h exposure in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. These alligator cathelicidin peptides have activity similar to other CAMPs from reptiles such as NA-CATH. It is possible that the alligator cathelicidins play an important role in the innate immune response of A. mississippiensis, similar to LL-37 in humans. In addition, due to their activities against MDR bacteria and lack of cytotoxicity, the AM-CATH peptides could be an attractive platform for further development as a potential therapeutic.
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Affiliation(s)
| | - Evelyn J Hrifko
- College of Science, George Mason University, Manassas, VA, USA
| | - Monique L van Hoek
- School of Systems Biology, George Mason University, Manassas, VA, USA; College of Science, George Mason University, Manassas, VA, USA; National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA, USA.
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15
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Caspar Y, Maurin M. Francisella tularensis Susceptibility to Antibiotics: A Comprehensive Review of the Data Obtained In vitro and in Animal Models. Front Cell Infect Microbiol 2017; 7:122. [PMID: 28443249 PMCID: PMC5386985 DOI: 10.3389/fcimb.2017.00122] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/27/2017] [Indexed: 11/13/2022] Open
Abstract
The antibiotic classes that are recommended for tularaemia treatment are the aminoglycosides, the fluoroquinolones and the tetracyclines. However, cure rates vary between 60 and 100% depending on the antibiotic used, the time to appropriate antibiotic therapy setup and its duration, and the presence of complications, such as lymph node suppuration. Thus, antibiotic susceptibility testing (AST) of F. tularensis strains remains of primary importance for detection of the emergence of antibiotic resistances to first-line drugs, and to test new therapeutic alternatives. However, the AST methods reported in the literature were poorly standardized between studies and AST data have not been previously evaluated in a comprehensive and comparative way. The aim of the present review was to summarize experimental data on antibiotic susceptibilities of F. tularensis obtained in acellular media, cell models and animal models since the introduction of fluoroquinolones in the treatment of tularaemia in 1989. We compiled MIC data of 33 antibiotics (including aminoglycosides, fluoroquinolones, tetracyclines, macrolides, β-lactams, chloramphenicol, rifampicin, and linezolid) against 900 F. tularensis strains (504 human strains), including 107 subsp. tularensis (type A), 789 subsp. holarctica (type B) and four subsp. mediasiatica strains, using various AST methods. Specific culture media were identified or confirmed as unsuitable for AST of F. tularensis. Overall, MICs were the lowest for ciprofloxacin (≤ 0.002-0.125 mg/L) and levofloxacin, and ranged from ≤ 0.016 to 2 mg/L for gentamicin, and 0.064 to 4 mg/L for doxycycline. No resistant strain to any of these antibiotics was reported. Fluoroquinolones also exhibited a bactericidal activity against intracellular F. tularensis and lower relapse rates in animal models when compared with the bacteriostatic compound doxycycline. As expected, lower MIC values were found for macrolides against type A and biovar I type B strains, compared to biovar II type B strains. The macrolides were more effective against F. tularensis grown in phagocytic cells than in acellular media.
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Affiliation(s)
- Yvan Caspar
- Laboratoire de Bactériologie-Hygiène Hospitalière, Département des agents infectieux, Centre National de Référence des Francisella, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble AlpesGrenoble, France
- Université Grenoble Alpes, Centre National de la Recherche Scientifique, TIMC-IMAGGrenoble, France
| | - Max Maurin
- Laboratoire de Bactériologie-Hygiène Hospitalière, Département des agents infectieux, Centre National de Référence des Francisella, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble AlpesGrenoble, France
- Université Grenoble Alpes, Centre National de la Recherche Scientifique, TIMC-IMAGGrenoble, France
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16
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Functional Characterization of the DNA Gyrases in Fluoroquinolone-Resistant Mutants of Francisella novicida. Antimicrob Agents Chemother 2017; 61:AAC.02277-16. [PMID: 28167561 DOI: 10.1128/aac.02277-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/20/2017] [Indexed: 11/20/2022] Open
Abstract
Fluoroquinolone (FQ) resistance is a major health concern in the treatment of tularemia. Because DNA gyrase has been described as the main target of these compounds, our aim was to clarify the contributions of both GyrA and GyrB mutations found in Francisella novicida clones highly resistant to FQs. Wild-type and mutated GyrA and GyrB subunits were overexpressed so that the in vitro FQ sensitivity of functional reconstituted complexes could be evaluated. The data obtained were compared to the MICs of FQs against bacterial clones harboring the same mutations and were further validated through complementation experiments and structural modeling. Whole-genome sequencing of highly FQ-resistant lineages was also done. Supercoiling and DNA cleavage assays demonstrated that GyrA D87 is a hot spot FQ resistance target in F. novicida and pointed out the role of the GyrA P43H substitution in resistance acquisition. An unusual feature of FQ resistance acquisition in F. novicida is that the first-step mutation occurs in GyrB, with direct or indirect consequences for FQ sensitivity. Insertion of P466 into GyrB leads to a 50% inhibitory concentration (IC50) comparable to that observed for a mutant gyrase carrying the GyrA D87Y substitution, while the D487E-ΔK488 mutation, while not active on its own, contributes to the high level of resistance that occurs following acquisition of the GyrA D87G substitution in double GyrA/GyrB mutants. The involvement of other putative targets is discussed, including that of a ParE mutation that was found to arise in the very late stage of antibiotic exposure. This study provides the first characterization of the molecular mechanisms responsible for FQ resistance in Francisella.
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Affiliation(s)
- Ryan J Blower
- a School of Systems Biology, George Mason University , Manassas , VA , USA
| | - Serguei G Popov
- a School of Systems Biology, George Mason University , Manassas , VA , USA
| | - Monique L van Hoek
- a School of Systems Biology, George Mason University , Manassas , VA , USA
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18
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Kaushal A, Gupta K, Shah R, van Hoek ML. Antimicrobial activity of mosquito cecropin peptides against Francisella. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 63:171-180. [PMID: 27235883 DOI: 10.1016/j.dci.2016.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 05/23/2016] [Accepted: 05/24/2016] [Indexed: 06/05/2023]
Abstract
Francisella tularensis is the cause of the zoonotic disease tularemia. In Sweden and Scandinavia, epidemiological studies have implicated mosquitoes as a vector. Prior research has demonstrated the presence of Francisella DNA in infected mosquitoes but has not shown definitive transmission of tularemia from a mosquito to a mammalian host. We hypothesized that antimicrobial peptides, an important component of the innate immune system of higher organisms, may play a role in mosquito host-defense to Francisella. We established that Francisella sp. are susceptible to two cecropin antimicrobial peptides derived from the mosquito Aedes albopictus as well as Culex pipiens. We also demonstrated induced expression of Aedes albopictus antimicrobial peptide genes by Francisella infection C6/36 mosquito cell line. We demonstrate that mosquito antimicrobial peptides act against Francisella by disrupting the cellular membrane of the bacteria. Thus, it is possible that antimicrobial peptides may play a role in the inability of mosquitoes to establish an effective natural transmission of tularemia.
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Affiliation(s)
- Akanksha Kaushal
- Department of Biology, George Mason University, Manassas, VA, USA
| | - Kajal Gupta
- College of Science, George Mason University, Fairfax, VA 22030, USA
| | - Ruhee Shah
- Thomas Jefferson School of Science and Technology, Alexandria, VA, USA
| | - Monique L van Hoek
- School of Systems Biology, George Mason University, Manassas, VA, USA; National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA 20110, USA.
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19
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Alterations in P-Glycoprotein Expression and Function Between Macrophage Subsets. Pharm Res 2016; 33:2713-21. [PMID: 27431863 DOI: 10.1007/s11095-016-1998-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 07/11/2016] [Indexed: 12/12/2022]
Abstract
PURPOSE Macrophages are an important cellular reservoir in HIV, and exist in two phenotypically dissimilar subsets, the pro-inflammatory M1 phenotype, and the anti-inflammatory M2 phenotype. The role of these two subsets is uncertain. We hypothesized that differences in drug efflux transporters exist between the subsets, which would result in altered intracellular drug concentrations between these cells. METHODS U937 monocytic cells were polarized to the M1 or M2 phenotype via treatment with interferon-gamma and LPS, or interleukins 4, 13, and LPS, respectively. PGP function was assessed with Hoechst 33342, and expression via western blotting. Intracellular lopinavir was assessed via LC-MS/MS. Data was confirmed with primary monocyte derived macrophages. RESULTS We observed significant differences in intracellular concentrations of lopinavir, a PGP substrate, with higher concentrations in M1 cells. PGP function and expression was higher in the M2 macrophages. These results were confirmed with primary monocyte derived macrophages. CONCLUSIONS This data shows that there are previously unreported differences in P-glycoprotein expression between macrophage subsets, and suggests that there may be differences for other transporters. These differences can play a role in intracellular drug concentrations in these cells, and may allow for low-level HIV replication.
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20
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Maurin M, Gyuranecz M. Tularaemia: clinical aspects in Europe. THE LANCET. INFECTIOUS DISEASES 2016; 16:113-124. [PMID: 26738841 DOI: 10.1016/s1473-3099(15)00355-2] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 09/17/2015] [Accepted: 09/21/2015] [Indexed: 10/22/2022]
Abstract
Tularaemia is a zoonotic disease caused by Francisella tularensis, a Gram-negative, facultative intracellular bacterium. Typically, human and animal infections are caused by F tularensis subspecies tularensis (type A) strains mainly in Canada and USA, and F tularensis subspecies holarctica (type B) strains throughout the northern hemisphere, including Europe. In the past, the epidemiological, clinical, therapeutic, and prognostic aspects of tularaemia reported in the English medical literature were mainly those that had been reported in the USA, where the disease was first described. Tularaemia has markedly changed in the past decade, and a large number of studies have provided novel data for the disease characteristics in Europe. In this Review we aim to emphasise the specific and variable aspects of tularaemia in different European countries. In particular, two natural lifecycles of F tularensis have been described in this continent, although not fully characterised, which are associated with different modes of transmission, clinical features, and public health burdens of tularaemia.
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Affiliation(s)
- Max Maurin
- Centre National de Référence des Francisella, Département des Agents Infectieux, Institut de Biologie et Pathologie, CHU de Grenoble, Grenoble, cedex 9, France; Université Grenoble Alpes and Centre National de la Recherche Scientifique, Laboratoire Adaptation et Pathogénie des Microorganismes, IMR 5163, Grenoble, France.
| | - Miklós Gyuranecz
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary; OIE Reference Laboratory for Tularemia, Budapest, Country
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21
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Propst CN, Pylypko SL, Blower RJ, Ahmad S, Mansoor M, van Hoek ML. Francisella philomiragia Infection and Lethality in Mammalian Tissue Culture Cell Models, Galleria mellonella, and BALB/c Mice. Front Microbiol 2016; 7:696. [PMID: 27252681 PMCID: PMC4877389 DOI: 10.3389/fmicb.2016.00696] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 04/26/2016] [Indexed: 12/15/2022] Open
Abstract
Francisella (F.) philomiragia is a Gram-negative bacterium with a preference for brackish environments that has been implicated in causing bacterial infections in near-drowning victims. The purpose of this study was to characterize the ability of F. philomiragia to infect cultured mammalian cells, a commonly used invertebrate model, and, finally, to characterize the ability of F. philomiragia to infect BALB/c mice via the pulmonary (intranasal) route of infection. This study shows that F. philomiragia infects J774A.1 murine macrophage cells, HepG2 cells and A549 human Type II alveolar epithelial cells. However, replication rates vary depending on strain at 24 h. F. philomiragia infection after 24 h was found to be cytotoxic in human U937 macrophage-like cells and J774A.1 cells. This is in contrast to the findings that F. philomiragia was non-cytotoxic to human hepatocellular carcinoma cells, HepG2 cells and A549 cells. Differential cytotoxicity is a point for further study. Here, it was demonstrated that F. philomiragia grown in host-adapted conditions (BHI, pH 6.8) is sensitive to levofloxacin but shows increased resistance to the human cathelicidin LL-37 and murine cathelicidin mCRAMP when compared to related the Francisella species, F. tularensis subsp. novicida and F. tularensis subsp. LVS. Previous findings that LL-37 is strongly upregulated in A549 cells following F. tularensis subsp. novicida infection suggest that the level of antimicrobial peptide expression is not sufficient in cells to eradicate the intracellular bacteria. Finally, this study demonstrates that F. philomiragia is lethal in two in vivo models; Galleria mellonella via hemocoel injection, with a LD50 of 1.8 × 103, and BALB/c mice by intranasal infection, with a LD50 of 3.45 × 103. In conclusion, F. philomiragia may be a useful model organism to study the genus Francisella, particularly for those researchers with interest in studying microbial ecology or environmental strains of Francisella. Additionally, the Biosafety level 2 status of F. philomiragia makes it an attractive model for virulence and pathogenesis studies.
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Affiliation(s)
- Crystal N Propst
- School of Systems Biology, George Mason University, Manassas, VA USA
| | | | - Ryan J Blower
- School of Systems Biology, George Mason University, Manassas, VA USA
| | - Saira Ahmad
- School of Systems Biology, George Mason University, Manassas, VA USA
| | | | - Monique L van Hoek
- School of Systems Biology, George Mason University, Manassas, VAUSA; National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VAUSA
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22
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Dean SN, van Hoek ML. Screen of FDA-approved drug library identifies maprotiline, an antibiofilm and antivirulence compound with QseC sensor-kinase dependent activity in Francisella novicida. Virulence 2016; 6:487-503. [PMID: 26155740 DOI: 10.1080/21505594.2015.1046029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Development of new therapeutics against Select Agents such as Francisella is critical preparation in the event of bioterrorism. Testing FDA-approved drugs for this purpose may yield new activities unrelated to their intended purpose and may hasten the discovery of new therapeutics. A library of 420 FDA-approved drugs was screened for antibiofilm activity against a model organism for human tularemia, Francisella (F.) novicida, excluding drugs that significantly inhibited growth. The initial screen was based on the 2-component system (TCS) dependent biofilm effect, thus, the QseC dependence of maprotiline anti-biofilm action was demonstrated. By comparing their FDA-approved uses, chemical structures, and other properties of active drugs, toremifene and polycyclic antidepressants maprotiline and chlorpromazine were identified as being highly active against F. novicida biofilm formation. Further down-selection excluded toremifene for its membrane active activity and chlorpromazine for its high antimicrobial activity. The mode of action of maprotiline against F. novicida was sought. It was demonstrated that maprotiline was able to significantly down-regulate the expression of the virulence factor IglC, encoded on the Francisella Pathogenicity Island (FPI), suggesting that maprotiline is exerting an effect on bacterial virulence. Further studies showed that maprotiline significantly rescued F. novicida infected wax worm larvae. In vivo studies demonstrated that maprotiline treatment could prolong time to disease onset and survival in F. novicida infected mice. These results suggest that an FDA-approved drug such as maprotiline has the potential to combat Francisella infection as an antivirulence agent, and may have utility in combination with antibiotics.
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Affiliation(s)
- Scott N Dean
- a National Center for Biodefense and Infectious Diseases ; Manassas , VA , USA
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23
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Utility of Greater Wax Moth Larva (Galleria mellonella) for Evaluating the Toxicity and Efficacy of New Antimicrobial Agents. ADVANCES IN APPLIED MICROBIOLOGY 2016; 78:25-53. [PMID: 22305092 DOI: 10.1016/b978-0-12-394805-2.00002-6] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
There is an urgent need for new antimicrobial agents to combat infections caused by drug-resistant pathogens. Once a compound is shown to be effective in vitro, it is necessary to evaluate its efficacy in an animal infection model. Typically, this is achieved using a mammalian model, but such experiments are costly, time consuming, and require full ethical consideration. Hence, cheaper and ethically more acceptable invertebrate models of infection have been introduced, including the larvae of the greater wax moth Galleria mellonella. Invertebrates have an immune system that is functionally similar to the innate immune system of mammals, and often identical virulence and pathogenicity factors are used by human pathogenic microbes to infect wax moth larvae and mammals. Moreover, the virulence of many human pathogens is comparable in wax moth larvae and mammals. Using key examples from the literature, this chapter highlights the benefits of using the wax moth larva model to provide a rapid, inexpensive, and reliable evaluation of the toxicity and efficacy of new antimicrobial agents in vivo and prior to the use of more expensive mammalian models. This simple insect model can bridge the gap between in vitro studies and mammalian experimentation by screening out compounds with a low likelihood of success, while providing greater justification for further studies in mammalian systems. Thus, broader implementation of the wax moth larva model into anti-infective drug discovery and development programs could reduce the use of mammals during preclinical assessments and the overall cost of drug development.
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Tsai CJY, Loh JMS, Proft T. Galleria mellonella infection models for the study of bacterial diseases and for antimicrobial drug testing. Virulence 2016; 7:214-29. [PMID: 26730990 PMCID: PMC4871635 DOI: 10.1080/21505594.2015.1135289] [Citation(s) in RCA: 445] [Impact Index Per Article: 55.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Galleria mellonella (greater wax moth or honeycomb moth) has been introduced as an alternative model to study microbial infections. G. mellonella larvae can be easily and inexpensively obtained in large numbers and are simple to use as they don't require special lab equipment. There are no ethical constraints and their short life cycle makes them ideal for large-scale studies. Although insects lack an adaptive immune response, their innate immune response shows remarkable similarities with the immune response in vertebrates. This review gives a current update of what is known about the immune system of G. mellonella and provides an extensive overview of how G. mellonella is used to study the virulence of Gram-positive and Gram-negative bacteria. In addition, the use of G. mellonella to evaluate the efficacy of antimicrobial agents and experimental phage therapy are also discussed. The review concludes with a critical assessment of the current limitatons of G. mellonella infection models.
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Affiliation(s)
- Catherine Jia-Yun Tsai
- a Department of Molecular Medicine & Pathology , School of Medical Sciences, University of Auckland , Auckland , New Zealand.,b Maurice Wilkins Center, University of Auckland , Auckland , New Zealand
| | - Jacelyn Mei San Loh
- a Department of Molecular Medicine & Pathology , School of Medical Sciences, University of Auckland , Auckland , New Zealand.,b Maurice Wilkins Center, University of Auckland , Auckland , New Zealand
| | - Thomas Proft
- a Department of Molecular Medicine & Pathology , School of Medical Sciences, University of Auckland , Auckland , New Zealand.,b Maurice Wilkins Center, University of Auckland , Auckland , New Zealand
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Aloni-Grinstein R, Shifman O, Lazar S, Steinberger-Levy I, Maoz S, Ber R. A rapid real-time quantitative PCR assay to determine the minimal inhibitory extracellular concentration of antibiotics against an intracellular Francisella tularensis Live Vaccine Strain. Front Microbiol 2015; 6:1213. [PMID: 26579112 PMCID: PMC4630301 DOI: 10.3389/fmicb.2015.01213] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/19/2015] [Indexed: 12/17/2022] Open
Abstract
Francisella tularensis is a highly virulent facultative intracellular bacterium. The lack of a safe and efficient vaccine makes antibiotics the preferred treatment. F. tularensis antibiotic susceptibility tests are based on the in vitro standard CLSI-approved microdilution method for determining the MIC. However, limited data are available regarding the minimal inhibitory extracellular concentration (MIEC) needed to eradicate intracellular bacteria. Here, we evaluated the MIEC values of various WHO-recommended antibiotics and compared the MIEC values to the established MICs. We describe a rapid 3-h quantitative PCR (qPCR) intracellular antibiogram assay, which yields comparable MIEC values to those obtained by the classical 72-h cfu assay. This rapid qPCR assay is highly advantageous in light of the slow growth rates of F. tularensis. Our results showed that the MIECs obtained for doxycycline, chloramphenicol and ciprofloxacin were indicative of intracellular activity. Gentamicin was not effective against intracellular bacteria for at least 32 h post treatment, raising the question of whether slow-penetrating gentamicin should be used for certain stages of the disease. We suggest that the qPCR intracellular antibiogram assay may be used to screen for potentially active antibiotics against intracellular F. tularensis as well as to detect strains with acquired resistance to recommended antibiotics.
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Affiliation(s)
- Ronit Aloni-Grinstein
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research Ness Ziona, Israel
| | - Ohad Shifman
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research Ness Ziona, Israel
| | - Shlomi Lazar
- Department of Pharmacology, Israel Institute for Biological Research Ness Ziona, Israel
| | - Ida Steinberger-Levy
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research Ness Ziona, Israel
| | - Sharon Maoz
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research Ness Ziona, Israel
| | - Raphael Ber
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research Ness Ziona, Israel
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Stephens MD, Hubble VB, Ernst RK, van Hoek ML, Melander RJ, Cavanagh J, Melander C. Potentiation of Francisella Resistance to Conventional Antibiotics through Small Molecule Adjuvants. MEDCHEMCOMM 2015; 7:128-131. [PMID: 26877862 DOI: 10.1039/c5md00353a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A screen of 20 compounds identified small molecule adjuvants capable of potentiating anitbiotic activty against Francisella philomiragia. Analogue synthesis of an initial hit compound led to the discovery of a potentially new class of small molecule adjuvants containg an indole core. The lead compound was able to lower the MIC of colistin by 32-fold against intrinsically resistant F. philomiragia.
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Affiliation(s)
- Matthew D Stephens
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Veroncia B Hubble
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland - Baltimore, Baltimore, MD 21201, United States
| | - Monique L van Hoek
- School of Systems Biology & National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, VA 20110, United States
| | - Roberta J Melander
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - John Cavanagh
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Christian Melander
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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Ulrey RK, Barksdale SM, Zhou W, van Hoek ML. Cranberry proanthocyanidins have anti-biofilm properties against Pseudomonas aeruginosa. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 14:499. [PMID: 25511463 PMCID: PMC4320558 DOI: 10.1186/1472-6882-14-499] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 12/11/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND Bacteria within a biofilm are phenotypically more resistant to antibiotics, desiccation, and the host immune system, making it an important virulence factor for many microbes. Cranberry juice has long been used to prevent infections of the urinary tract, which are often related to biofilm formation. Recent studies have found that the A-type proanthocyanidins from cranberries have anti-biofilm properties against Escherichia coli. METHODS Using crystal violet biofilm staining, resazurin metabolism assays, and confocal imaging, we examined the ability of A-type proanthocyanidins (PACs) to disrupt the biofilm formation of Pseudomonas aeruginosa. We used mass spectrometry to analyze the proteomic effects of PAC treatment. We also performed synergy assays and in vitro and in vivo infections to determine whether PACs, alone and in combination with gentamicin, could contribute to the killing of P. aeruginosa and the survival of cell lines and G. mellonella. RESULTS Cranberry PACs reduced P. aeruginosa swarming motility. Cranberry PACs significantly disrupted the biofilm formation of P. aeruginosa. Proteomics analysis revealed significantly different proteins expressed following PAC treatment. In addition, we found that PACs potentiated the antibiotic activity of gentamicin in an in vivo model of infection using G. mellonella. CONCLUSIONS Results suggest that A-type proanthocyanidins may be a useful therapeutic against the biofilm-mediated infections caused by P. aeruginosa and should be further tested.
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Affiliation(s)
- Robert K Ulrey
- />Department of Biology, George Mason University, Manassas, Virginia USA
| | | | - Weidong Zhou
- />Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia USA
| | - Monique L van Hoek
- />School of Systems Biology, George Mason University, Manassas, Virginia USA
- />National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia USA
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Doak B, Over B, Giordanetto F, Kihlberg J. Oral Druggable Space beyond the Rule of 5: Insights from Drugs and Clinical Candidates. ACTA ACUST UNITED AC 2014; 21:1115-42. [DOI: 10.1016/j.chembiol.2014.08.013] [Citation(s) in RCA: 282] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Celik T, Kosker M, Kirboga K. An atypical case of tularemia presented with pseudoptosis. Infection 2014; 42:785-8. [PMID: 24659144 DOI: 10.1007/s15010-014-0613-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/05/2014] [Indexed: 11/26/2022]
Abstract
We report an unusual case of tularemia involving pseudoptosis associated with deterioration of the lymphatic drainage system extending from the upper eyelid to the preauricular lymph nodes. A 16-week pregnant patient was admitted with an absess on the neck, preauricular lymphadenopathy, and pseudoptosis on the left side. The micro-agglutination test was positive for Francisella tularensis antibody at a titer of 1/200. The absess was surgically drained and oral cefuroxime was given for 6 weeks. Two weeks after drainage, the pseudoptosis improved due to the recovery of lymphatic drainage system of the eyelid and remission of the absess on the neck. Our case report contributes to the medical literature on tularemia during pregnancy and informs healthcare professionals on the management of the infection in such cases.
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Affiliation(s)
- T Celik
- Department of Ophthalmology, Bolu Gerede State Hospital, Seviller St., Gerede-Bolu, 14900, Turkey,
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Sutera V, Caspar Y, Boisset S, Maurin M. A new dye uptake assay to test the activity of antibiotics against intracellular Francisella tularensis. Front Cell Infect Microbiol 2014; 4:36. [PMID: 24672776 PMCID: PMC3957058 DOI: 10.3389/fcimb.2014.00036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 02/24/2014] [Indexed: 11/13/2022] Open
Abstract
Francisella tularensis, a facultative intracellular bacterium, is the aetiological agent of tularaemia. Antibiotic treatment of this zoonosis is based on the administration of a fluoroquinolone or a tetracycline for cases with mild to moderate severity, whereas an aminoglycoside (streptomycin or gentamicin) is advocated for severe cases. However, treatment failures and relapses remain frequent, especially in patients suffering from chronic lymph node suppuration. Therefore, new treatment alternatives are needed. We have developed a dye uptake assay for determination of minimal inhibitory extracellular concentrations (MIECs) of antibiotics against intracellular F. tularensis, and validated the method by comparing the results obtained using a CFU-enumerating method. We also compared MIECs with MICs of the same compounds determined using a CLSI broth microdilution method. We tested the activity of 11 antibiotics against two clinical strains of F. tularensis subsp. holarctica isolated in France. Both strains displayed low MICs (≤1 μg/mL) to fluoroquinolones (ciprofloxacin, levofloxacin and moxifloxacin), gentamicin, doxycycline and rifampicin. Higher MICs (≥8 μg/mL) were found for carbapenems (imipenem and meropenem), daptomycin and linezolid. Erythromycin MICs were 4.0 and 16.0 μg/mL, respectively, for the two clinical strains. MIECs were almost the same with the two methods used. They were concordant with MICs, except for erythromycin and linezolid (respectively, four and eight times more active against intracellular F. tularensis) and gentamicin (four to eight times less active against intracellular F. tularensis). This study validated the dye uptake assay as a new tool for determination of the activity of a large panel of antibiotics against intracellular F. tularensis. This test confirmed the intracellular activity of first-line antibiotics used for tularaemia treatment, but also revealed significant activity of linezolid against intracellular F. tularensis.
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Affiliation(s)
- Vivien Sutera
- Laboratoire de Bactériologie, Département des Agents Infectieux, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble Grenoble, France ; Laboratoire Adaptation et Pathogénie des Micro-Organismes, Université Joseph Fourier-Grenoble 1 Grenoble Cedex 9, France ; CNRS, UMR 5163 Grenoble, France
| | - Yvan Caspar
- Laboratoire de Bactériologie, Département des Agents Infectieux, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble Grenoble, France ; Laboratoire Adaptation et Pathogénie des Micro-Organismes, Université Joseph Fourier-Grenoble 1 Grenoble Cedex 9, France ; CNRS, UMR 5163 Grenoble, France
| | - Sandrine Boisset
- Laboratoire de Bactériologie, Département des Agents Infectieux, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble Grenoble, France ; Laboratoire Adaptation et Pathogénie des Micro-Organismes, Université Joseph Fourier-Grenoble 1 Grenoble Cedex 9, France ; CNRS, UMR 5163 Grenoble, France
| | - Max Maurin
- Laboratoire de Bactériologie, Département des Agents Infectieux, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble Grenoble, France ; Laboratoire Adaptation et Pathogénie des Micro-Organismes, Université Joseph Fourier-Grenoble 1 Grenoble Cedex 9, France ; CNRS, UMR 5163 Grenoble, France
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Dentan C, Pavese P, Pelloux I, Boisset S, Brion JP, Stahl JP, Maurin M. Treatment of tularemia in pregnant woman, France. Emerg Infect Dis 2013; 19:996-8. [PMID: 23735285 PMCID: PMC3713841 DOI: 10.3201/eid1906.130138] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A pregnant woman who had oropharyngeal tularemia underwent treatment with azithromycin and lymph node resection and recovered without obstetrical complication or infection in the child. Azithromycin represents a first-line treatment option for tularemia during pregnancy in regions where the infecting strains of Francisella tularensis have no natural resistance to macrolides.
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32
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Examination of in vitro epithelial cell lines as models for Francisella tularensis non-phagocytic infections. J Microbiol Methods 2013; 93:153-60. [DOI: 10.1016/j.mimet.2013.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 03/04/2013] [Accepted: 03/11/2013] [Indexed: 01/16/2023]
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Kourtesi C, Ball AR, Huang YY, Jachak SM, Vera DMA, Khondkar P, Gibbons S, Hamblin MR, Tegos GP. Microbial efflux systems and inhibitors: approaches to drug discovery and the challenge of clinical implementation. Open Microbiol J 2013; 7:34-52. [PMID: 23569468 PMCID: PMC3617545 DOI: 10.2174/1874285801307010034] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/22/2013] [Accepted: 01/23/2013] [Indexed: 12/16/2022] Open
Abstract
Conventional antimicrobials are increasingly ineffective due to the emergence of multidrug-resistance among pathogenic microorganisms. The need to overcome these deficiencies has triggered exploration for novel and unconventional approaches to controlling microbial infections. Multidrug efflux systems (MES) have been a profound obstacle in the successful deployment of antimicrobials. The discovery of small molecule efflux system blockers has been an active and rapidly expanding research discipline. A major theme in this platform involves efflux pump inhibitors (EPIs) from natural sources. The discovery methodologies and the available number of natural EPI-chemotypes are increasing. Advances in our understanding of microbial physiology have shed light on a series of pathways and phenotypes where the role of efflux systems is pivotal. Complementing existing antimicrobial discovery platforms such as photodynamic therapy (PDT) with efflux inhibition is a subject under investigation. This core information is a stepping stone in the challenge of highlighting an effective drug development path for EPIs since the puzzle of clinical implementation remains unsolved. This review summarizes advances in the path of EPI discovery, discusses potential avenues of EPI implementation and development, and underlines the need for highly informative and comprehensive translational approaches.
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Affiliation(s)
- Christina Kourtesi
- Department of Pathology, University of New Mexico, School of Medicine, Albuquerque, NM, USA ; Department of Pathology, Faculty of Medicine, National & Kapodistrian University of Athens, Greece
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Yamasaki S, Nagasawa S, Fukushima A, Hayashi-Nishino M, Nishino K. Cooperation of the multidrug efflux pump and lipopolysaccharides in the intrinsic antibiotic resistance of Salmonella enterica serovar Typhimurium. J Antimicrob Chemother 2013; 68:1066-70. [PMID: 23378414 PMCID: PMC3625434 DOI: 10.1093/jac/dks528] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES In Gram-negative bacteria, drug susceptibility is associated with multidrug efflux systems and an outer membrane (OM) barrier. Previous studies revealed that Salmonella enterica serovar Typhimurium has 10 functional drug efflux pumps. Among them, AcrB is a major factor to maintain the intrinsic drug resistance in this organism. The lipopolysaccharide (LPS) content of OM is also important for resistance to lipophilic drugs; however, the interplay between the multidrug efflux pump and LPS in the intrinsic antibiotic resistance of Salmonella remains to be studied in detail. The aim of this study was to investigate the relationship between AcrB and LPS in the intrinsic drug resistance of this organism. METHODS The genes encoding LPS core biosynthetic proteins and AcrB were disrupted from the wild-type S. enterica strain ATCC 14028s. The plasmid carrying acrB was transformed into these mutants and then the drug susceptibilities of the mutants and transformants were determined. RESULTS Our results showed that the levels of Salmonella intrinsic antibiotic resistance were decreased when the length and branches of core oligosaccharide were lost. Furthermore, the deletion of acrB reduced multidrug resistance of all LPS mutants and AcrB production from the plasmid complemented this phenotype. However, AcrB production could not completely compensate for LPS function in intrinsic resistance. CONCLUSIONS Both pump inactivation and shortened LPS enhanced drug susceptibility, although the maximum susceptibility was achieved when the two were combined. Hence, these results indicated that the multidrug efflux system and OM barrier are both essential for maintaining intrinsic antibiotic resistance in Salmonella.
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Affiliation(s)
- Seiji Yamasaki
- Laboratory of Microbiology and Infectious Diseases, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Bradburne CE, Verhoeven AB, Manyam GC, Chaudhry SA, Chang EL, Thach DC, Bailey CL, van Hoek ML. Temporal transcriptional response during infection of type II alveolar epithelial cells with Francisella tularensis live vaccine strain (LVS) supports a general host suppression and bacterial uptake by macropinocytosis. J Biol Chem 2013; 288:10780-91. [PMID: 23322778 DOI: 10.1074/jbc.m112.362178] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Pneumonic tularemia is caused by inhalation of Francisella tularensis, one of the most infectious microbes known. We wanted to study the kinetics of the initial and early interactions between bacterium and host cells in the lung. To do this, we examined the infection of A549 airway epithelial cells with the live vaccine strain (LVS) of F. tularensis. A549 cells were infected and analyzed for global transcriptional response at multiple time points up to 16 h following infection. At 15 min and 2 h, a strong transcriptional response was observed including cytoskeletal rearrangement, intracellular transport, and interferon signaling. However, at later time points (6 and 16 h), very little differential gene expression was observed, indicating a general suppression of the host response consistent with other reported cell lines and murine tissues. Genes for macropinocytosis and actin/cytoskeleton rearrangement were highly up-regulated and common to the 15 min and 2 h time points, suggesting the use of this method for bacterial entry into cells. We demonstrate macropinocytosis through the uptake of FITC-dextran and amiloride inhibition of Francisella LVS uptake. Our results suggest that macropinocytosis is a potential mechanism of intracellular entry by LVS and that the host cell response is suppressed during the first 2-6 h of infection. These results suggest that the attenuated Francisella LVS induces significant host cell signaling at very early time points after the bacteria's interaction with the cell.
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Affiliation(s)
- Christopher E Bradburne
- Center for Bio/Molecular Science and Engineering, United States Naval Research Laboratory, Washington, DC 20375, USA
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36
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Utility of insects for studying human pathogens and evaluating new antimicrobial agents. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2013; 135:1-25. [PMID: 23604210 DOI: 10.1007/10_2013_194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
Insect models, such as Galleria mellonella and Drosophila melanogaster have significant ethical, logistical, and economic advantages over mammalian models for the studies of infectious diseases. Using these models, various pathogenic microbes have been studied and many novel virulence genes have been identified. Notably, because insects are susceptible to a wide variety of human pathogens and have immune responses similar to those of mammals, they offer the opportunity to understand innate immune responses against human pathogens better. It is important to note that insect pathosystems have also offered a simple strategy to evaluate the efficacy and toxicity of many antimicrobial agents. Overall, insect models provide a rapid, inexpensive, and reliable way as complementary hosts to conventional vertebrate animal models to study pathogenesis and antimicrobial agents.
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McKenney ES, Sargent M, Khan H, Uh E, Jackson ER, Jose GS, Couch RD, Dowd CS, van Hoek ML. Lipophilic prodrugs of FR900098 are antimicrobial against Francisella novicida in vivo and in vitro and show GlpT independent efficacy. PLoS One 2012; 7:e38167. [PMID: 23077474 PMCID: PMC3471904 DOI: 10.1371/journal.pone.0038167] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 05/04/2012] [Indexed: 01/01/2023] Open
Abstract
Bacteria, plants, and algae produce isoprenoids through the methylerythritol phosphate (MEP) pathway, an attractive pathway for antimicrobial drug development as it is present in prokaryotes and some lower eukaryotes but absent from human cells. The first committed step of the MEP pathway is catalyzed by 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR/MEP synthase). MEP pathway genes have been identified in many biothreat agents, including Francisella, Brucella, Bacillus, Burkholderia, and Yersinia. The importance of the MEP pathway to Francisella is demonstrated by the fact that MEP pathway mutations are lethal. We have previously established that fosmidomycin inhibits purified MEP synthase (DXR) from F. tularensis LVS. FR900098, the acetyl derivative of fosmidomycin, was found to inhibit the activity of purified DXR from F. tularensis LVS (IC50 = 230 nM). Fosmidomycin and FR900098 are effective against purified DXR from Mycobacterium tuberculosis as well, but have no effect on whole cells because the compounds are too polar to penetrate the thick cell wall. Fosmidomycin requires the GlpT transporter to enter cells, and this is absent in some pathogens, including M. tuberculosis. In this study, we have identified the GlpT homologs in F. novicida and tested transposon insertion mutants of glpT. We showed that FR900098 also requires GlpT for full activity against F. novicida. Thus, we synthesized several FR900098 prodrugs that have lipophilic groups to facilitate their passage through the bacterial cell wall and bypass the requirement for the GlpT transporter. One compound, that we termed “compound 1,” was found to have GlpT-independent antimicrobial activity. We tested the ability of this best performing prodrug to inhibit F. novicida intracellular infection of eukaryotic cell lines and the caterpillar Galleria mellonella as an in vivo infection model. As a lipophilic GlpT-independent DXR inhibitor, compound 1 has the potential to be a broad-spectrum antibiotic, and should be effective against most MEP-dependent organisms.
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Affiliation(s)
- Elizabeth S. McKenney
- School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Michelle Sargent
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Hameed Khan
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Eugene Uh
- Department of Chemistry, George Washington University, Washington, D.C., United States of America
| | - Emily R. Jackson
- Department of Chemistry, George Washington University, Washington, D.C., United States of America
| | - Géraldine San Jose
- Department of Chemistry, George Washington University, Washington, D.C., United States of America
| | - Robin D. Couch
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia, United States of America
| | - Cynthia S. Dowd
- Department of Chemistry, George Washington University, Washington, D.C., United States of America
| | - Monique L. van Hoek
- School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia, United States of America
- * E-mail:
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Mackie RS, McKenney ES, van Hoek ML. Resistance of Francisella novicida to fosmidomycin associated with mutations in the glycerol-3-phosphate transporter. Front Microbiol 2012; 3:226. [PMID: 22905031 PMCID: PMC3417576 DOI: 10.3389/fmicb.2012.00226] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/01/2012] [Indexed: 01/23/2023] Open
Abstract
The methylerythritol phosphate (MEP) pathway is essential in most prokaryotes and some lower eukaryotes but absent from human cells, and is a validated target for antimicrobial drug development. The formation of MEP is catalyzed by 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR). MEP pathway genes have been identified in many category A and B biothreat agents, including Francisella tularensis, which causes the zoonosis tularemia. Fosmidomycin (Fos) inhibits purified Francisella DXR. This compound also inhibits the growth of F. tularensis NIH B38, F. novicida and F. tularensis subsp. holarctica LVS bacteria. Related compounds such as FR900098 and the lipophilic prodrug of FR900098 (compound 1) have been developed to improve the bioavailability of these DXR inhibitors. In performing disk-inhibition assays with these compounds, we observed breakthrough colonies of F. novicida in the presence of Fos, suggesting spontaneous development of Fos resistance (Fos(R)). Fos(R) bacteria had decreased sensitivity to both Fos and FR900098. The two most likely targets for the development of mutants would be the DXR enzyme itself or the glycerol-3-phosphate transporter (GlpT) that allows entry of Fos into the bacteria. Sensitivity of Fos(R)F. novicida bacteria to compound 1 was not abated suggesting that spontaneous resistance is not due to mutation of DXR. We thus predicted that the glpT transporter may be mutated leading to this resistant phenotype. Supporting this, transposon insertion mutants at the glpT locus were also found to be resistant to Fos. DNA sequencing of four different spontaneous Fos(R) colonies demonstrated a variety of deletions in the glpT coding region. The overall frequency of Fos(R) mutations in F. novicida was determined to be 6.3 × 10(-8). Thus we conclude that one mechanism of resistance of F. novicida to Fos is caused by mutations in GlpT. This is the first description of spontaneous mutations in Francisella leading to Fos(R).
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Affiliation(s)
- Ryan S Mackie
- School of Systems Biology, George Mason University Manassas, VA, USA
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Pierson T, Matrakas D, Taylor YU, Manyam G, Morozov VN, Zhou W, van Hoek ML. Proteomic Characterization and Functional Analysis of Outer Membrane Vesicles of Francisella novicida Suggests Possible Role in Virulence and Use as a Vaccine. J Proteome Res 2011; 10:954-67. [DOI: 10.1021/pr1009756] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tony Pierson
- Department of Molecular and Microbiology, George Mason University, Manassas, Virginia 20110, United States
| | - Demetrios Matrakas
- Department of Molecular and Microbiology, George Mason University, Manassas, Virginia 20110, United States
| | - Yuka U. Taylor
- Department of Molecular and Microbiology, George Mason University, Manassas, Virginia 20110, United States
| | - Ganiraju Manyam
- Department of Bioinformatics & Computational Biology, The UT MD Anderson Cancer Center, Houston, Texas, United States
| | - Victor N. Morozov
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110, United States
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region 142290, Russia
| | - Weidong Zhou
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia 20110, United States
| | - Monique L. van Hoek
- Department of Molecular and Microbiology, George Mason University, Manassas, Virginia 20110, United States
- National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110, United States
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Stundick MV, Metz M, Sampath A, Larsen JC. State-of-the-art therapeutic medical countermeasures for bacterial threat agents. Drug Dev Res 2011. [DOI: 10.1002/ddr.20462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Gestin B, Valade E, Thibault F, Schneider D, Maurin M. Phenotypic and genetic characterization of macrolide resistance in Francisella tularensis subsp. holarctica biovar I. J Antimicrob Chemother 2010; 65:2359-67. [PMID: 20837574 DOI: 10.1093/jac/dkq315] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Francisella tularensis subsp. holarctica strains are classified as biovars I and II, which are susceptible and naturally resistant to the macrolide erythromycin, respectively. The present study was aimed at both selecting biovar I strains with increased levels of erythromycin resistance and characterizing the underlying genetic mechanisms. METHODS Serial cultures in the presence of increasingly high erythromycin concentrations were performed to select independent high- and intermediate-level erythromycin-resistant mutants from each of three different biovar I strains. The mutants were characterized for cross-resistance to several antibiotics, presence of mutations in the genes encoding the 23S rRNA and the L4 and L22 ribosomal proteins, and overexpression of efflux pumps. RESULTS Mutants displayed cross-resistance to all macrolide compounds tested but not to other classes of antibiotics. We found mutations in domain V of the 23S rRNA gene (G2057A, A2058G, A2058T and C2611T) and in the gene encoding L22, leading to either the G91D substitution or the M82K83R84 deletion. Analysis of mutants with intermediate resistance levels obtained over the course of the selection process revealed both a positive correlation between the number of mutated ribosomal operons and the resistance level, and an additional resistance mechanism in the early steps of selection. CONCLUSIONS We showed that high-level resistance to macrolides can be easily obtained in vitro in F. tularensis subsp. holarctica biovar I strains, thereby suggesting that in vivo selection for resistance may explain reported failures of antibiotic treatment. Ketolides were the most effective macrolides tested, which may limit the risk of selection for resistance.
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Affiliation(s)
- Brieuc Gestin
- CNRS UMR 5163 and Laboratoire Adaptation et Pathogénie des Micro-organismes, Université Joseph Fourier Grenoble 1, BP 170, F-38042 Grenoble Cedex 9, France
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