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Reinseth I, Diep DB, Kjos M, Tønnesen HH, Carlsen H. Exploring the feasibility of bacteriocins EntK1 and EntEJ97s in treatment of systemic vancomycin resistant enterococci infections in mice. J Appl Microbiol 2024; 135:lxae054. [PMID: 38439668 DOI: 10.1093/jambio/lxae054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/21/2024] [Accepted: 03/01/2024] [Indexed: 03/06/2024]
Abstract
AIMS Enterocins K1 and EJ97 have specific antimicrobial activity against Enterococcus faecium and Enterococcus faecalis, respectively. The aim of this study was to investigate the utility of these enterocins for in vivo treatment of systemic enterococcal infections. METHODS AND RESULTS The antimicrobial effect in blood was analysed and compared against the effect in saline. Colony forming unit counts revealed that the enterocins killed all the bacteria within 1 hour. Additionally, the bactericidal effect against E. faecalis was more rapid in blood, indicating a possible synergy between EntEJ97 and blood. Importantly, no enterocin resistant mutants emerged in these experiments. Injecting the enterocins intraperitoneally in an in vivo mouse model and using fluorescence and minimum inhibitory concentration determination to estimate concentrations of the peptides in plasma, indicate that the enterocins exist in circulation in therapeutic concentrations. Alanine aminotransferase detection, and haemolysis analysis indicates that there is no detectable liver damage or haemolytic effect after injection. CONCLUSIONS The study revealed that EntK1 and EntEJ97 are able to kill all bacteria ex vivo in the presence of blood. In vivo experiments determine that the enterocins exist in circulation in therapeutic concentrations without causing liver damage or haemolysis. Future experiments should test these peptides for treatment of infection in a relevant in vivo model.
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Affiliation(s)
- Ingvild Reinseth
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
| | - Dzung B Diep
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
| | - Hanne H Tønnesen
- Section of Pharmaceutics and Social Pharmacy, Department of Pharmacy, University of Oslo, P.O. Box 1068 Blindern 0316 Oslo, Norway
| | - Harald Carlsen
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, P.O. Box 5003 1432 Ås, Norway
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2
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Xu W, Fang Y, Zhu K. Enterococci facilitate polymicrobial infections. Trends Microbiol 2024; 32:162-177. [PMID: 37550091 DOI: 10.1016/j.tim.2023.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/15/2023] [Accepted: 07/18/2023] [Indexed: 08/09/2023]
Abstract
Enterococci are ubiquitous members of the gut microbiota in human beings and animals and are among the most important nosocomial organisms. Due to their opportunistic pathogenicity, enterococci are referred to as pathobionts and play decisive roles in a diverse array of polymicrobial infections. Enterococci can promote the colonization, pathogenesis, and persistence of various pathogens, compromise the efficacy of drugs, and pose a severe threat to public health. Most current treatments tend to focus on the sole pathogenic bacteria, with insufficient attention to the driving role of enterococci. In this review, we summarize the characteristics of enterococci in infections, the factors facilitating their outgrowth, as well as the sites and types of enterococci-associated polymicrobial infections. We present an overview of the underlying mechanisms of enterococci-mediated pathogenesis in polymicrobial infections. Furthermore, we discuss alternative strategies and potential intervention approaches to restrict such infections, shedding light on the discovery and development of new therapies against polymicrobial infections.
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Affiliation(s)
- Wenjiao Xu
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Engineering Research Center of Animal Innovative Drugs and Safety Evaluation, Ministry of Education, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yuwen Fang
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Engineering Research Center of Animal Innovative Drugs and Safety Evaluation, Ministry of Education, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Kui Zhu
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Engineering Research Center of Animal Innovative Drugs and Safety Evaluation, Ministry of Education, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
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3
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Kang X, Wei Y, Fan X, Luo S, Luo X, Zhao S, Wang G. Analysis of virulence genes, drug resistance detection, and pathogenicity in Enterococcus from farm animals. Microb Pathog 2022; 171:105745. [PMID: 36057414 DOI: 10.1016/j.micpath.2022.105745] [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: 05/24/2022] [Revised: 08/20/2022] [Accepted: 08/25/2022] [Indexed: 11/28/2022]
Abstract
This study aimed to investigate the presence of eight virulence genes (ace, asa1, esp, efaA, gelE, cylA, agg, fsr) in Enterococcus from a variety of animals and to explore the drug resistance and pathogenicity. This could provide a theoretical basis for clinical treatment of Enterococcus infections. Anal swabs from pigs, chickens, cattle, and dogs in farms and pet hospitals were collected for Enterococcus isolation and identification. Eight virulence genes were detected (PCR method), and drug resistance was assessed (drug-sensitive paper method). The strains containing different virulence genes were then divided into EV1, EV2, and EV3 groups. The LD50 and pathogenicity was examined by intra-peritoneal injection to infect mice. Differences were found in the detection rates of virulence genes in Enterococcus from the different animals. The highest overall detection rate was for the esp gene (78.0%), and the lowest for the cylA gene (15.5%). Eight genes were detected most frequently in Enterococcus from dogs and least frequently from cattle. Among the Enterococcus strains from four variety of animals, drug resistance was highest against sulfamethoxazole (100%), cefotaxime (>97%), and cefotaxitin (>93%). Drug resistance was lowest against vancomycin (0%), levofloxacin (<12%) and ciprofloxacin (<13%). The LD50 for each of the three groups was EV1LD50=8.71×109CFU, EV2LD50=2.34×1010CFU,and EV3LD50=9.33×1010CFU. The Enterococcus12LD50 dose group caused significant clinical symptoms in mice, with pathological effects on the heart, liver, lungs, and kidneys, and particularly on the urinary system. The abundance of Enterococcus virulence genes, drug resistance, and pathogenicity vary among different animal origins, and the pathology caused by Enterococcus requires effective treatment protocols based on species and regional characteristics.
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Affiliation(s)
- Xinyun Kang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Yanqin Wei
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Xiaofei Fan
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Shuangyan Luo
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Xiaofeng Luo
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Sijun Zhao
- Chinese Center for Animal Health and Epidemiology, Qingdao, Shandong, China.
| | - Guiqin Wang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China.
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4
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Nunez N, Derré-Bobillot A, Trainel N, Lakisic G, Lecomte A, Mercier-Nomé F, Cassard AM, Bierne H, Serror P, Archambaud C. The unforeseen intracellular lifestyle of Enterococcus faecalis in hepatocytes. Gut Microbes 2022; 14:2058851. [PMID: 35373699 PMCID: PMC8986240 DOI: 10.1080/19490976.2022.2058851] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Enterococcus faecalis is a bacterial species present at a subdominant level in the human gut microbiota. This commensal turns into an opportunistic pathogen under specific conditions involving dysbiosis and host immune deficiency. E. faecalis is one of the rare pathobionts identified to date as contributing to liver damage in alcoholic liver disease. We have previously observed that E. faecalis is internalized in hepatocytes. Here, the survival and fate of E. faecalis was examined in hepatocytes, the main epithelial cell type in the liver. Although referred to as an extracellular pathogen, we demonstrate that E. faecalis is able to survive and divide in hepatocytes, and form intracellular clusters in two distinct hepatocyte cell lines, in primary mouse hepatocytes, as well as in vivo. This novel process extends to kidney cells. Unraveling the intracellular lifestyle of E. faecalis, our findings contribute to the understanding of pathobiont-driven diseases.
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Affiliation(s)
- Natalia Nunez
- Université -Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | | | - Nicolas Trainel
- Université Paris-Saclay, Inserm U996, Inflammation, Microbiome and Immunosurveillance, Clamart, France
| | - Goran Lakisic
- Université -Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Alexandre Lecomte
- Université -Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Françoise Mercier-Nomé
- Université Paris-Saclay, INSERM, CNRS, Institut Paris Saclay d’Innovation Thérapeutique, Châtenay-Malabry, France
| | - Anne-Marie Cassard
- Université Paris-Saclay, Inserm U996, Inflammation, Microbiome and Immunosurveillance, Clamart, France
| | - Hélène Bierne
- Université -Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Pascale Serror
- Université -Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France,CONTACT Pascale Serror Université Paris-Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Cristel Archambaud
- Université -Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France,Cristel Archambaud Université Paris-Saclay, Inrae, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
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5
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Alotaibi G, Khan K, Al Mouslem AK, Ahmad Khan S, Naseer Abbas M, Abbas M, Ali Shah S, Jalal K. Pan Genome Based Reverse Vaccinology Approach to Explore Enterococcus Faecium (VRE) Strains for Identification of Novel Multi-Epitopes Vaccine Candidate. Immunobiology 2022; 227:152221. [DOI: 10.1016/j.imbio.2022.152221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/24/2022] [Accepted: 04/15/2022] [Indexed: 11/05/2022]
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6
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Capietto AH, Lee S, Clever D, Eul E, Ellis H, Ma CX, Faccio R. Effective Treatment of Established Bone Metastases Can Be Achieved by Combinatorial Osteoclast Blockade and Depletion of Granulocytic Subsets. Cancer Immunol Res 2021; 9:1400-1412. [PMID: 34551967 PMCID: PMC8642282 DOI: 10.1158/2326-6066.cir-21-0232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/14/2021] [Accepted: 09/16/2021] [Indexed: 11/16/2022]
Abstract
Osteoclast (OC) blockade has been successful in reducing tumor growth in bone in preclinical settings, but antiresorptive drugs, such as zoledronic acid (ZA), fail to improve the overall survival rate of patients with bone metastasis despite ameliorating skeletal complications. To address this unmet clinical need, we interrogated what other cells modulated tumor growth in bone in addition to OCs. Because myeloid-derived suppressor cells (MDSC)-heterogeneous populations expressing CD11b, Ly6C, and Ly6G markers-originate in the bone marrow and promote tumor progression, we hypothesized that their accumulation hinders ZA antitumor effects. By using a murine model of bone metastasis insensitive to OC blockade, we assessed the antitumor effect of MDSC depletion using anti-Gr1 in mice bearing skeletal lung [Lewis lung carcinoma (LLC)], melanoma (B16-F10), and mammary (4T1) tumors. Differently from soft tissue tumors, anti-Gr1 did not reduce bone metastases and led to the paradoxical accumulation of bone marrow-resident CD11b+Ly6CintLy6Gint cells that differentiated into OCs when cultured in vitro Anti-Gr1-mediated depletion of Ly6G+ granulocytic MDSCs combined with ZA-induced OC blockade reduced growth of established skeletal metastases compared with each agent alone. CD15+ granulocytic populations were increased in patients with breast cancer with progressive bone disease after antiresorptive treatment compared with those with stable bone disease. We provide evidence that antiresorptive therapies fail to reduce bone metastases in the presence of elevated granulocytic populations and that effective treatment of established skeletal metastases requires combinatorial depletion of granulocytes and OC blockade.
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Affiliation(s)
- Aude-Hélène Capietto
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri
- Shriners Hospitals for Children, St. Louis, Missouri
| | - Seunghyun Lee
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - David Clever
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Emily Eul
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Haley Ellis
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Cynthia X Ma
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Roberta Faccio
- Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri.
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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7
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Fatoba AJ, Adeleke VT, Maharaj L, Okpeku M, Adeniyi AA, Adeleke MA. Immunoinformatics Design of Multiepitope Vaccine Against Enterococcus faecium Infection. Int J Pept Res Ther 2021. [DOI: 10.1007/s10989-021-10245-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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8
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Inhibition of the Classical Pathway of Complement Activation Impairs Bacterial Clearance during Enterococcus faecalis Infection. Infect Immun 2021; 89:IAI.00660-20. [PMID: 33593889 DOI: 10.1128/iai.00660-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
Enterococcus faecalis infections are considered a major public health concern worldwide. The complement system has a crucial role in the protection against different microbial pathogens, including E. faecalis Complement can be activated through three different pathways, including the classical, lectin, and alternative pathways. There is limited information on the role of the classical pathway (CP) in protection against infections caused by E. faecalis In the present study, we generated Fab fragments that successfully block the CP in mouse via inhibition of a key enzyme, C1s-A. Our results showed that anti-C1s-A Fab fragments block CP-mediated C3b and C4b deposition in vitro We further showed that administration of anti-C1s-A Fab fragments significantly impairs the CP functional activity in vivo Moreover, treatment of mice infected with E. faecalis using anti-C1s-A Fab fragments significantly impairs bacterial clearance as determined from the viable bacterial counts recovered from blood, kidneys, spleens, livers, and lungs of infected mice. Overall, this study highlights the essential role of the CP in host defense against E. faecalis.
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9
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Kalfopoulou E, Huebner J. Advances and Prospects in Vaccine Development against Enterococci. Cells 2020; 9:cells9112397. [PMID: 33147722 PMCID: PMC7692742 DOI: 10.3390/cells9112397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/29/2020] [Accepted: 10/30/2020] [Indexed: 12/26/2022] Open
Abstract
Enterococci are the second most common Gram-positive pathogen responsible for nosocomial infections. Due to the limited number of new antibiotics that reach the medical practice and the resistance of enterococci to the current antibiotic options, passive and active immunotherapies have emerged as a potential prevention and/or treatment strategy against this opportunistic pathogen. In this review, we explore the pathogenicity of these bacteria and their interaction with the host immune response. We provide an overview of the capsular polysaccharides and surface-associated proteins that have been described as potential antigens in anti-enterococcal vaccine formulations. In addition, we describe the current status in vaccine development against enterococci and address the importance and the current advances toward the development of well-defined vaccines with broad coverage against enterococci.
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Affiliation(s)
- Ermioni Kalfopoulou
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University of Munich, 81675 Munich, Germany;
| | - Johannes Huebner
- Division of Paediatric Infectious Diseases, Dr. von Hauner Children’s Hospital, Ludwig Maximilians University, 80337 Munich, Germany
- Correspondence: ; Tel.: +49-89-44005-7970
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10
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Abstract
Neutrophils are an essential part of the innate immune system. To study their importance, experimental studies often aim to deplete these cells, generally by injecting anti-Ly6G or anti-Gr1 antibodies. However, these approaches are only partially effective, transient or lack specificity. Here we report that neutrophils remaining after anti-Ly6G treatment are newly derived from the bone marrow, instead of depletion escapees. Mechanistically, newly generated, circulating neutrophils have lower Ly6G membrane expression, and consequently reduced targets for anti-Ly6G-mediated depletion. To overcome this limitation, we develop a double antibody-based depletion strategy that enhances neutrophil elimination by anti-Ly6G treatment. This approach achieves specific, durable and controlled reduction of neutrophils in vivo, and may be suitable for studying neutrophil function in experimental models. Anti-Ly6G or ant-Gr1 antibodies are commonly used to deplete neutrophils in vivo. Here the authors provide mechanistic insight into why these approaches may not specifically or durably reduce the number of neutrophils in mice, and also present a new method that overcomes these limitations to have potentially wide applicability in experimental studies.
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11
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Romero-Saavedra F, Laverde D, Kalfopoulou E, Martini C, Torelli R, Martinez-Matamoros D, Sanguinetti M, Huebner J. Conjugation of Different Immunogenic Enterococcal Vaccine Target Antigens Leads to Extended Strain Coverage. J Infect Dis 2020; 220:1589-1598. [PMID: 31289829 PMCID: PMC6782101 DOI: 10.1093/infdis/jiz357] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 07/08/2019] [Indexed: 11/28/2022] Open
Abstract
Enterococci have emerged as important nosocomial pathogens due to their resistance to the most commonly used antibiotics. Alternative treatments or prevention options are aimed at polysaccharides and surface-related proteins that play important roles in pathogenesis. Previously, we have shown that 2 Enterococcus faecium proteins, the secreted antigen A and the peptidyl-prolyl cis-trans isomerase, as well as the Enterococcus faecalis polysaccharide diheteroglycan, are able to induce opsonic and cross-protective antibodies. Here, we evaluate the use of glycoconjugates consisting of these proteins and an enterococcal polysaccharide to develop a vaccine with broader strain coverage. Diheteroglycan was conjugated to these 2 enterococcal proteins. Rabbit sera raised against these glycoconjugates showed Immunoglobulin G titers against the corresponding conjugate, as well as against the respective protein and carbohydrate antigens. Effective opsonophagocytic killing for the 2 sera was observed against different E. faecalis and E. faecium strains. Enzyme-linked immunosorbent assays against whole bacterial cells showed immune recognition of 22 enterococcal strains by the sera. Moreover, the sera conferred protection against E. faecalis and E. faecium strains in a mouse infection model. Our results suggest that these glycoconjugates are promising candidates for vaccine formulations with a broader coverage against these nosocomial pathogens and that the evaluated proteins are potential carrier proteins.
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Affiliation(s)
- F Romero-Saavedra
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children's Hospital, Ludwig Maximillian's University, Munich, Germany
| | - D Laverde
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children's Hospital, Ludwig Maximillian's University, Munich, Germany
| | - E Kalfopoulou
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children's Hospital, Ludwig Maximillian's University, Munich, Germany
| | - C Martini
- Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy
| | - R Torelli
- Dipartimento di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome, Italy
| | - D Martinez-Matamoros
- Department of Chemistry, Faculty of Sciences and Center for Advanced Scientific Research (CICA), Universidade da Coruña, A Coruña, Spain
| | - M Sanguinetti
- Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy.,Dipartimento di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome, Italy
| | - J Huebner
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children's Hospital, Ludwig Maximillian's University, Munich, Germany
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12
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The Dysbiosis and Inter-Kingdom Synergy Model in Oropharyngeal Candidiasis, a New Perspective in Pathogenesis. J Fungi (Basel) 2019; 5:jof5040087. [PMID: 31546600 PMCID: PMC6958497 DOI: 10.3390/jof5040087] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 12/28/2022] Open
Abstract
As more information emerges on oral microbiota using advanced sequencing methodologies, it is imperative to examine how organisms modulate the capacity of each other to colonize or trigger infection. Most mouse models of oral C. albicans infection have focused on interactions with single bacterial species. Thus, little is known about the microbiome-mediated interactions that control the switch of C. albicans from commensalism to infection. Evidence is accumulating that in immunosuppression where mucosal candidiasis is more prevalent, there is an altered oral bacterial microbiome with reduced diversity, but not an altered mycobiome. Oropharyngeal candidiasis in immunosuppressed humans and mice is associated with a further reduction in oral bacterial diversity and a dysbiotic shift with significant enrichment of streptococcal and enterococcal species. Our recent studies in a cancer chemotherapy mouse model supported the combined profound effect of immunosuppression and C. albicans in reducing oral bacterial diversity and provided the first direct evidence that these changes contribute to pathogenesis, representing dysbiosis. There is still a gap in understanding the relationship between Candida and the oral bacterial microbiome. We propose that certain oral commensal bacteria contribute to fungal pathogenesis and we identify gaps in our understanding of the mechanisms involved in this cooperative virulence.
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13
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Kazemian H, Pourmand MR, Siadat SD, Mahdavi M, Yazdi MH, Avakh Majelan P, Afshar D, Yaseri M, Davari M, Getso MI. Molecular Cloning and Immunogenicity Evaluation of PpiC, GelE, and VS87_01105 Proteins of Enterococcus faecalis as Vaccine Candidates. IRANIAN BIOMEDICAL JOURNAL 2019; 23. [PMID: 31103023 PMCID: PMC6661130 DOI: 10.29252/.23.5.344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Background Among the enterococci strains, Enterococcus faecalis is considered as one of the important nosocomial pathogens affecting immunocompromised patients. In this study, the immunogenicity of PpiC, GelE, and VS87_01105 proteins against enterococcal infection was investigated in a mice model. Methods The genes encoding these proteins were cloned into pET21a expression vector, and the recombinant proteins were produced. Mice and rabbits were immunized with the purified recombinant proteins, and subsequently, mice were challenged with E. faecalis for the evaluation of their survival and bacterial clearances. The antibody responses to recombinant proteins were determined by ELISA assay, and opsonophagocytic activities of the antibodies were also measured. Passive immunization was performed using purified antibodies. Mice were challenged, and their survival and bacterial clearance were determined. Results Immunized mice with PpiC, GelE, and VS87_01105 recombinant proteins showed 80%, 70%, and 40% survival rate, respectively. The survival rates among passively immunized mice that received 500 µg of IgG fraction in 100 µl PBS buffer of each of anti-PpiC, anti-GelE, and anti-VS87_01105 were 60%, 50%, and 20%, respectively. The rates of opsonization with anti-PpiC, anti-GelE, and anti-VS87_01105 antibodies at 1/10 dilution were 77%, 64%, and 23%, respectively. Conclusion Based on our findings, PpiC, and GelE proteins can protect the mice against E. faecalis ATCC 29212 and effectively induce a protective antibody response. Thus, these proteins could be used as an additional therapeutic tool against enterococcal infections. Further studies to determine the role of PpiC in ligand binding and demonstration of epitope mapping may establish a credible target for vaccination.
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Affiliation(s)
- Hamid Kazemian
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Pourmand
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; ,Corresponding Author: Mohammad Reza Pourmand ,Department of Pathobiology, School of Public Health and Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran; Mobile: (+98-912) 5168520; E-mail:
| | - Seyed Davar Siadat
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Mehdi Mahdavi
- Recombinant Vaccine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hossein Yazdi
- Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Peyman Avakh Majelan
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Davoud Afshar
- Department of Microbiology and Virology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Mehdi Yaseri
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Davari
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Muhammad Ibrahim Getso
- Department of Medical Mycology, School of Public Health, Tehran University of Medical Sciences, International College, Tehran, Iran
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14
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Ali YM, Sim RB, Schwaeble W, Shaaban MI. Enterococcus faecalis Escapes Complement-Mediated Killing via Recruitment of Complement Factor H. J Infect Dis 2019; 220:1061-1070. [PMID: 31058287 DOI: 10.1093/infdis/jiz226] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/01/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Enterococcus faecalis is considered to be the most important species of enterococci responsible for blood stream infections in critically ill patients. In blood, the complement system is activated via the classical pathway (CP), the lectin pathway (LP), or the alternative pathway (AP), and it plays a critical role in opsonophagocytosis of bacteria including E faecalis. METHODS In a mouse model of enterococcus peritonitis, BALB-C mice were challenged with a high dose of E faecalis 12 hours after intraperitoneal administration of anti-Factor H (FH) antibodies or isotype control. Four hours later, control mice developed higher bacterial burden in blood and organs compared with mice treated with anti-FH antibodies. RESULTS We demonstrate that complement recognition molecules C1q, CL-11, and murine ficolin-A bind the enterococcus and drive the CP and the LP in human and mouse. We further describe that E faecalis evades the AP by recruitment of FH on its surface. Our results show a strong C3b deposition on E faecalis via both the CP and the LP but not through the AP. CONCLUSIONS These findings indicate that E faecalis avoids the complement phagocytosis by the AP via sequestering complement FH from the host blood.
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Affiliation(s)
- Youssif M Ali
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Egypt
- Department of Veterinary Medicine, School of Biological Sciences, University of Cambridge, United Kingdom
| | - Robert B Sim
- Department of Pharmacology, Oxford University, United Kingdom
| | - Wilhelm Schwaeble
- Department of Veterinary Medicine, School of Biological Sciences, University of Cambridge, United Kingdom
| | - Mona I Shaaban
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Egypt
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15
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Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci. Microbiol Mol Biol Rev 2019; 83:83/3/e00008-19. [PMID: 31315902 DOI: 10.1128/mmbr.00008-19] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.
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16
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Fiore E, Van Tyne D, Gilmore MS. Pathogenicity of Enterococci. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0053-2018. [PMID: 31298205 PMCID: PMC6629438 DOI: 10.1128/microbiolspec.gpp3-0053-2018] [Citation(s) in RCA: 195] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Indexed: 12/19/2022] Open
Abstract
Enterococci are unusually well adapted for survival and persistence in a variety of adverse environments, including on inanimate surfaces in the hospital environment and at sites of infection. This intrinsic ruggedness undoubtedly played a role in providing opportunities for enterococci to interact with other overtly drug-resistant microbes and acquire additional resistances on mobile elements. The rapid rise of antimicrobial resistance among hospital-adapted enterococci has rendered hospital-acquired infections a leading therapeutic challenge. With about a quarter of a genome of additional DNA conveyed by mobile elements, there are undoubtedly many more properties that have been acquired that help enterococci persist and spread in the hospital setting and cause diseases that have yet to be defined. Much remains to be learned about these ancient and rugged microbes, particularly in the area of pathogenic mechanisms involved with human diseases.
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Affiliation(s)
- Elizabeth Fiore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Daria Van Tyne
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Michael S Gilmore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
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17
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Bertolini M, Ranjan A, Thompson A, Diaz PI, Sobue T, Maas K, Dongari-Bagtzoglou A. Candida albicans induces mucosal bacterial dysbiosis that promotes invasive infection. PLoS Pathog 2019; 15:e1007717. [PMID: 31009520 PMCID: PMC6497318 DOI: 10.1371/journal.ppat.1007717] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 05/02/2019] [Accepted: 03/19/2019] [Indexed: 12/12/2022] Open
Abstract
Infectious complications are a common cause of morbidity and mortality in cancer patients undergoing chemotherapy due to increased risk of oral and gastrointestinal candidiasis, candidemia and septicemia. Interactions between C. albicans and endogenous mucosal bacteria are important in understanding the mechanisms of invasive infection. We published a mouse intravenous chemotherapy model that recapitulates oral and intestinal mucositis, and myelosuppression in patients receiving 5-fluorouracil. We used this model to study the influence of C. albicans on the mucosal bacterial microbiome and compared global community changes in the oral and intestinal mucosa of the same mice. We validated 16S rRNA gene sequencing data by qPCR, in situ hybridization and culture approaches. Mice receiving both 5Fu and C. albicans had an endogenous bacterial overgrowth on the oral but not the small intestinal mucosa. C. albicans infection was associated with loss of mucosal bacterial diversity in both sites with indigenous Stenotrophomonas, Alphaproteobacteria and Enterococcus species dominating the small intestinal, and Enterococcus species dominating the oral mucosa. Both immunosuppression and Candida infection contributed to changes in the oral microbiota. Enterococci isolated from mice with oropharyngeal candidiasis were implicated in degrading the epithelial junction protein E-cadherin and increasing the permeability of the oral epithelial barrier in vitro. Importantly, depletion of these organisms with antibiotics in vivo attenuated oral mucosal E-cadherin degradation and C. albicans invasion without affecting fungal burdens, indicating that bacterial community changes represent overt dysbiosis. Our studies demonstrate a complex interaction between C. albicans, the resident mucosal bacterial microbiota and the host environment in pathogenesis. We shed significant new light on the role of C. albicans in shaping resident bacterial communities and driving mucosal dysbiosis.
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Affiliation(s)
- Martinna Bertolini
- Department of Oral Health Sciences, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Amit Ranjan
- Department of Oral Health Sciences, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Angela Thompson
- Department of Oral Health Sciences, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Patricia I. Diaz
- Department of Oral Health Sciences, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Takanori Sobue
- Department of Oral Health Sciences, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Kendra Maas
- Microbial Analysis, Resources, and Services Core, University of Connecticut, Storrs, Connecticut, United States of America
| | - Anna Dongari-Bagtzoglou
- Department of Oral Health Sciences, University of Connecticut Health Center, Farmington, Connecticut, United States of America
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18
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Bertolini M, Dongari-Bagtzoglou A. The Relationship of Candida albicans with the Oral Bacterial Microbiome in Health and Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1197:69-78. [PMID: 31732935 DOI: 10.1007/978-3-030-28524-1_6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Candida albicans is an opportunistic pathogen colonizing the oropharyngeal, esophageal, and gastrointestinal mucosa in most healthy humans. In immunocompromised hosts, this fungal organism can cause mucosal candidiasis in these sites. C. albicans also causes fungemia, a serious consequence of cancer cytotoxic chemotherapy, which is thought to develop from fungal translocation through compromised mucosal barriers. Changes in endogenous bacterial population size or composition as well as changes in the host environment can transform fungal commensals into opportunistic pathogens in the upper and lower GI tract. Pioneering studies from our group have shown that a ubiquitous oral commensal of the mitis streptococcal group (Streptococcus oralis) has a mutualistic relationship with C. albicans, with C. albicans enabling streptococcal biofilm growth at mucosal sites, and S. oralis facilitating invasion of the oral and esophageal mucosa by C. albicans. In these studies, we used a cortisone-induced immunosuppression mouse model. More recently, the development of a novel mouse chemotherapy model has allowed us to examine the interactions of C. albicans with the endogenous bacterial microbiota in the oral and small intestinal mucosa, two sites adversely affected by cytotoxic chemotherapy. In this model, oral inoculation with C. albicans causes severe dysbiosis in the mucosal bacterial composition in both sites. We also found that antibiotic treatment ameliorates invasion of the oral mucosa but aggravates dissemination through the intestinal mucosa. In this chapter, we discuss work from our laboratory and others examining the relationships of C. albicans with oral bacteria and their role in mucosal homeostasis or disease.
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Affiliation(s)
- Martinna Bertolini
- Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, CT, USA
| | - Anna Dongari-Bagtzoglou
- Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, CT, USA.
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19
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van der Meer AJ, Ding C, Hoogendijk AJ, de Vos AF, Boon L, Zeerleder SS, van der Poll T. Neutrophils mitigate the systemic host response during endotoxemia in mice. Immunology 2018; 156:277-281. [PMID: 30472736 PMCID: PMC6376271 DOI: 10.1111/imm.13026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 11/01/2018] [Accepted: 11/07/2018] [Indexed: 12/29/2022] Open
Abstract
Recent studies have suggested that neutrophils can exert anti-inflammatory effects. To determine the role of neutrophils in the acute response to lipopolysaccharide (LPS), a component of the Gram-negative bacterial cell wall, we challenged neutrophil-depleted and control mice with LPS and analyzed the plasma concentrations of biomarkers indicative of the cytokine and chemokine network, activation of coagulation and the vascular endothelium, and cellular injury. We here show that neutrophils serve an anti-inflammatory role upon LPS administration, as reflected by sustained elevations of multiple cytokines and chemokines, and enhanced release of nucleosomes in mice depleted of neutrophils, compared with control mice.
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Affiliation(s)
- Anne Jan van der Meer
- Center of Experimental & Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Chao Ding
- Center of Experimental & Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,Department of Gastric Surgery, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Arie Johan Hoogendijk
- Center of Experimental & Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Alex F de Vos
- Center of Experimental & Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Sacha S Zeerleder
- Department of Haematology and Central Haematology Laboratory, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.,Department for BioMedical Research, Bern University Hospital, University of Bern, Bern, Switzerland.,Department of Immunopathology, Sanquin Research, and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Tom van der Poll
- Center of Experimental & Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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20
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Hong W, Liu L, Zhao Y, Liu Y, Zhang D, Liu M. Pluronic-based nano-self-assemblies of bacitracin A with a new mechanism of action for an efficient in vivo therapeutic effect against bacterial peritonitis. J Nanobiotechnology 2018; 16:66. [PMID: 30205822 PMCID: PMC6131780 DOI: 10.1186/s12951-018-0397-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 09/05/2018] [Indexed: 11/29/2022] Open
Abstract
Background Although assemblies of hydrophobic-modified bacitracin A with PLGA (Nano-BAPLGA) have demonstrated promising antibacterial activities against both Gram-positive and Gram-negative bacteria, the desirable antibacterial potency has remained challenging due to the low solubility of Nano-BAPLGA. To address this tissue, a series of Pluronic copolymers (Pluronic® F127, Pluronic® P123 and Pluronic® P85) were selected to link the N-terminus of bacitracin A to construct Pluronic-based nano-self assemblies (Nano-BAF127, Nano-BAP123 and Nano-BAP85). Results Impressively, all the newly designed Pluronic-based Nano-BAs possessed higher solubility and stronger effectiveness against both Gram-positive and Gram-negative bacteria compared with Nano-BAPLGA, especially the modification with Pluronic® P85. Surface tension measurements indicated that Nano-BAP85 was much more tensioactive than Nano-BAPLGA, which usually translated into a good membranolytic effect. Fluorescence spectroscopy and electron microscopy analyses confirmed the speculation that the cell wall/membrane might be the main action target of Nano-BAP85 by permeabilizing the cell membrane and damaging the membrane integrity. In vivo results further demonstrated that Nano-BAP85 significantly suppressed bacterial growth and prolonged survival time in the bacterial peritonitis mouse model with negligible toxicity. Conclusions Collectively, the membrane targeting mechanism of action is entirely distinct from those of clinically used antibacterial agents. Furthermore, the new approach of construction nanoantibiotics based on the modification of commercially available antibiotics with Pluronic copolymers is demonstrated to have an efficient therapeutic effect against bacterial infection. Electronic supplementary material The online version of this article (10.1186/s12951-018-0397-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wei Hong
- Key Laboratory of Zoonosis of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Dongling Road 120, Shenyang, 110866, Liaoning, People's Republic of China.
| | - Lipeng Liu
- Key Laboratory of Zoonosis of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Dongling Road 120, Shenyang, 110866, Liaoning, People's Republic of China
| | - Yining Zhao
- Key Laboratory of Zoonosis of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Dongling Road 120, Shenyang, 110866, Liaoning, People's Republic of China
| | - Yinghui Liu
- Key Laboratory of Zoonosis of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Dongling Road 120, Shenyang, 110866, Liaoning, People's Republic of China
| | - Dexian Zhang
- Key Laboratory of Zoonosis of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Dongling Road 120, Shenyang, 110866, Liaoning, People's Republic of China
| | - Mingchun Liu
- Key Laboratory of Zoonosis of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Dongling Road 120, Shenyang, 110866, Liaoning, People's Republic of China
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21
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Group IIA-Secreted Phospholipase A 2 in Human Serum Kills Commensal but Not Clinical Enterococcus faecium Isolates. Infect Immun 2018; 86:IAI.00180-18. [PMID: 29784864 DOI: 10.1128/iai.00180-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/18/2018] [Indexed: 11/20/2022] Open
Abstract
Human innate immunity employs cellular and humoral mechanisms to facilitate rapid killing of invading bacteria. The direct killing of bacteria by human serum is attributed mainly to the activity of the complement system, which forms pores in Gram-negative bacteria. Although Gram-positive bacteria are considered resistant to killing by serum, we uncover here that normal human serum effectively kills Enterococcus faecium Comparison of a well-characterized collection of commensal and clinical E. faecium isolates revealed that human serum specifically kills commensal E. faecium strains isolated from normal gut microbiota but not clinical isolates. Inhibitor studies show that the human group IIA secreted phospholipase A2 (hGIIA), but not complement, is responsible for killing of commensal E. faecium strains in human normal serum. This is remarkable since the hGIIA concentration in "noninflamed" serum was considered too low to be bactericidal against Gram-positive bacteria. Mechanistic studies showed that serum hGIIA specifically causes permeabilization of commensal E. faecium membranes. Altogether, we find that a normal concentration of hGIIA in serum effectively kills commensal E. faecium and that resistance of clinical E. faecium to hGIIA could have contributed to the ability of these strains to become opportunistic pathogens in hospitalized patients.
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22
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Claushuis TAM, van der Donk LEH, Luitse AL, van Veen HA, van der Wel NN, van Vught LA, Roelofs JJTH, de Boer OJ, Lankelma JM, Boon L, de Vos AF, van 't Veer C, van der Poll T. Role of Peptidylarginine Deiminase 4 in Neutrophil Extracellular Trap Formation and Host Defense during Klebsiella pneumoniae-Induced Pneumonia-Derived Sepsis. THE JOURNAL OF IMMUNOLOGY 2018; 201:1241-1252. [PMID: 29987161 DOI: 10.4049/jimmunol.1800314] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/19/2018] [Indexed: 12/23/2022]
Abstract
Peptidylarginine deiminase 4 (PAD4) catalyzes citrullination of histones, an important step for neutrophil extracellular trap (NET) formation. We aimed to determine the role of PAD4 during pneumonia. Markers of NET formation were measured in lavage fluid from airways of critically ill patients. NET formation and host defense were studied during pneumonia-derived sepsis caused by Klebsiella pneumoniae in PAD4+/+ and PAD4-/- mice. Patients with pneumosepsis, compared with those with nonpulmonary disease, showed increased citrullinated histone 3 (CitH3) levels in their airways and a trend toward elevated levels of NET markers cell-free DNA and nucleosomes. During murine pneumosepsis, CitH3 levels were increased in the lungs of PAD4+/+ but not of PAD4-/- mice. Combined light and electron microscopy showed NET-like structures surrounding Klebsiella in areas of CitH3 staining in the lung; however, these were also seen in PAD4-/- mice with absent CitH3 lung staining. Moreover, cell-free DNA and nucleosome levels were mostly similar in both groups. Moreover, Klebsiella and LPS could still induce NETosis in PAD4-/- neutrophils. Both groups showed largely similar bacterial growth, lung inflammation, and organ injury. In conclusion, these data argue against a major role for PAD4 in NET formation, host defense, or organ injury during pneumonia-derived sepsis.
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Affiliation(s)
- Theodora A M Claushuis
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands;
| | - Lieve E H van der Donk
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Anna L Luitse
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Henk A van Veen
- Electron Microscopy Center Amsterdam, Department of Medical Biology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Nicole N van der Wel
- Electron Microscopy Center Amsterdam, Department of Medical Biology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Lonneke A van Vught
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Joris J T H Roelofs
- Department of Pathology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Onno J de Boer
- Department of Pathology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Jacqueline M Lankelma
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Louis Boon
- Bioceros, 3584 CM Utrecht, the Netherlands; and
| | - Alex F de Vos
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Cornelis van 't Veer
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
| | - Tom van der Poll
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands.,Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, the Netherlands
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23
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Halbgebauer R, Schmidt CQ, Karsten CM, Ignatius A, Huber-Lang M. Janus face of complement-driven neutrophil activation during sepsis. Semin Immunol 2018; 37:12-20. [PMID: 29454576 DOI: 10.1016/j.smim.2018.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 12/28/2022]
Abstract
During local and systemic inflammation, the complement system and neutrophil granulocytes are activated not only by pathogens, but also by released endogenous danger signals. It is recognized increasingly that complement-mediated neutrophil activation plays an ambivalent role in sepsis pathophysiology. According to the current definition, the onset of organ dysfunction is a hallmark of sepsis. The preceding organ damage can be caused by excessive complement activation and neutrophil actions against the host, resulting in bystander injury of healthy tissue. However, in contrast, persistent and overwhelming inflammation also leads to a reduction in neutrophil responsiveness as well as complement components and thus may render patients at enhanced risk of spreading infection. This review provides an overview on the molecular and cellular processes that link complement with the two-faced functional alterations of neutrophils in sepsis. Finally, we describe novel tools to modulate this interplay beneficially in order to improve outcome.
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Affiliation(s)
- R Halbgebauer
- Institute of Clinical and Experimental Trauma Immunology, Ulm University Hospital, Helmholtzstr. 8/1, 89081 Ulm, Germany.
| | - C Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Helmholtzstr. 20, 89081 Ulm, Germany.
| | - C M Karsten
- Institute for Systemic Inflammation Research, University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany.
| | - A Ignatius
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstr. 14, 89081 Ulm, Germany.
| | - M Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, Ulm University Hospital, Helmholtzstr. 8/1, 89081 Ulm, Germany.
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24
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Kajihara T, Nakamura S, Iwanaga N, Oshima K, Hirano K, Miyazaki T, Izumikawa K, Yanagihara K, Miyazaki Y, Hattori N, Kohno N, Kohno S, Mukae H. Comparative efficacies of daptomycin, vancomycin, and linezolid in experimental enterococcal peritonitis. J Infect Chemother 2017; 23:498-501. [PMID: 28108098 DOI: 10.1016/j.jiac.2016.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/21/2016] [Accepted: 12/02/2016] [Indexed: 10/20/2022]
Abstract
Enterococci have become increasingly important pathogens for nosocomial infection (e.g. bacteremia, intra-abdominal infection, endocarditis, etc.), related to their intrinsic resistance to many antibiotics. Although the in vitro susceptibility of daptomycin (DAP) against Enterococci is well established, the Food and Drug Administration has only approved its use for complicated skin and skin structure infections induced by Enterococcus faecalis. In this study we evaluated the potential therapeutic application of DAP in a murine model of enterococcal experimental peritonitis. Mice were injected intraperitoneally with 4 × 1010 colony-forming units of Enterococcus faecium. DAP alone, DAP combined with ampicillin, vancomycin, or linezolid were administered 2 h after enterococcal inoculation and examined the survival, viable bacteria counts, the level of KC/CXCL1 in the peritoneal fluid. The viable bacteria counts in the peritoneal fluid of the DAP- or DAP plus ampicillin-treated groups were decreased significantly compared to those of the vancomycin- and linezolid-treated groups (P < 0.05) at 6 and 12 h after the inoculation of Enterococcus. The level of neutrophil chemoattractants KC in the peritoneal fluid at 12 h after enterococcal inoculation was significantly decreased in the DAP plus ampicillin-treated group (P < 0.05). In addition DAP showed the inhibitory effect of enterococcal biofilm formation dose-dependently by a microtiter biofilm assay. These results indicate that DAP, particularly with β-lactams, is a possible alternative agent to treat severe enterococcal infection such as peritonitis.
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Affiliation(s)
- Toshiki Kajihara
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Department of Molecular and Internal Medicine, Hiroshima University, Graduate School of Biomedical Sciences, Hiroshima, Japan
| | - Shigeki Nakamura
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Tokyo, Japan.
| | - Naoki Iwanaga
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Kazuhiro Oshima
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Katsuji Hirano
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Taiga Miyazaki
- Department of Infectious Diseases, Unit of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Koichi Izumikawa
- Department of Infectious Diseases, Unit of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Katsunori Yanagihara
- Department of Laboratory Medicine, Nagasaki University Hospital, Nagasaki, Japan
| | - Yoshitsugu Miyazaki
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Tokyo, Japan
| | - Noboru Hattori
- Department of Molecular and Internal Medicine, Hiroshima University, Graduate School of Biomedical Sciences, Hiroshima, Japan
| | - Nobuoki Kohno
- Department of Molecular and Internal Medicine, Hiroshima University, Graduate School of Biomedical Sciences, Hiroshima, Japan
| | - Shigeru Kohno
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Hiroshi Mukae
- Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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25
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Zou J, Shankar N. Surface protein Esp enhances pro-inflammatory cytokine expression through NF-κB activation during enterococcal infection. Innate Immun 2015; 22:31-9. [PMID: 26503704 DOI: 10.1177/1753425915611237] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 09/21/2015] [Indexed: 11/17/2022] Open
Abstract
Enterococcal surface protein (Esp) is encoded on a pathogenicity island in Enterococcus faecalis and E. faecium and is involved in biofilm formation and binding to epithelial cells. In this study, using Esp-expressing E. faecalis MMH594 and its isogenic Esp-deficient strain, as well as purified Esp, we show that Esp is sufficient for activation of NF-κB and the subsequent production of pro-inflammatory cytokines IL-1β and TNF-α in macrophages in vitro. In a mouse peritonitis model, we also show that mice infected with Esp-expressing E. faecalis showed comparatively higher levels of cytokines TNF-α, IL-1β and IL-6 in peritoneal fluid, and IL-6 in serum. Moreover, neutrophil infiltration and tissue damage in the liver was higher in the mice infected with the Esp-expressing strain compared with mice infected with the Esp-deficient mutant. These results add Esp to the growing list of enterococcal virulence factors that can modulate inflammation during infection and has implications for enterococcal pathogenesis.
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Affiliation(s)
- Jun Zou
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Nathan Shankar
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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26
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Theilacker C, Diederich AK, Otto A, Sava IG, Wobser D, Bao Y, Hese K, Broszat M, Henneke P, Becher D, Huebner J. Enterococcus faecalis Glycolipids Modulate Lipoprotein-Content of the Bacterial Cell Membrane and Host Immune Response. PLoS One 2015; 10:e0132949. [PMID: 26172831 PMCID: PMC4501811 DOI: 10.1371/journal.pone.0132949] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 06/21/2015] [Indexed: 12/25/2022] Open
Abstract
In this study, we investigated the impact of the cell membrane composition of E. faecalis on its recognition by the host immune system. To this end, we employed an E. faecalis deletion mutant (ΔbgsA) that does not synthesize the major cell membrane glycolipid diglycosyl-diacylglycerol (DGlcDAG). Proteomic analysis revealed that 13 of a total of 21 upregulated surface-associated proteins of E. faecalis ΔbgsA were lipoproteins. This led to a total lipoprotein content in the cell membrane of 35.8% in ΔbgsA compared to only 9.4% in wild-type bacteria. Increased lipoprotein content strongly affected the recognition of ΔbgsA by mouse macrophages in vitro with an increased stimulation of TNF-α production by heat-fixed bacteria and secreted antigens. Inactivation of the prolipoprotein diacylglycerol transferase (lgt) in ΔbgsA abrogated TNF-α induction by a ΔbgsA_lgt double mutant indicating that lipoproteins mediate increased activation of mouse macrophages by ΔbgsA. Heat-fixed ΔbgsA bacteria, culture supernatant, or cell membrane lipid extract activated transfected HEK cells in a TLR2-dependent fashion; the same was not true of wild-type bacteria. In mice infected intraperitoneally with a sublethal dose of E. faecalis we observed a 70% greater mortality in mice infected with ΔbgsA compared with wild-type-infected mice. Increased mortality due to ΔbgsA infection was associated with elevated plasma levels of the inflammatory cytokines TNF-α, IL-6 and MIP-2. In summary, our results provide evidence that an E. faecalis mutant lacking its major bilayer forming glycolipid DGlcDAG upregulates lipoprotein expression leading to increased activation of the host innate immune system and virulence in vivo.
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Affiliation(s)
- Christian Theilacker
- Center for Chronic Immunodeficiency (CCI), University Medical Center Freiburg, Freiburg, Germany
- Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Freiburg, Germany
- * E-mail:
| | - Ann-Kristin Diederich
- Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Freiburg, Germany
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany
- Department of Microbiology, Faculty of Biology, Albert-Ludwigs-University, Freiburg, Germany
| | - Andreas Otto
- Institute for Microbiology, Department of Microbial Physiology, Ernst-Moritz-Arndt-University, Greifswald, Germany
| | - Irina G. Sava
- Research Center for Nutrition and Food Science, Technical University Munich, Freising, Germany
| | - Dominique Wobser
- Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Yinyin Bao
- Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Katrin Hese
- Center for Chronic Immunodeficiency (CCI), University Medical Center Freiburg, Freiburg, Germany
| | - Melanie Broszat
- Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Philipp Henneke
- Center for Chronic Immunodeficiency (CCI), University Medical Center Freiburg, Freiburg, Germany
- Center for Paediatrics and Adolescent Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Dörte Becher
- Institute for Microbiology, Department of Microbial Physiology, Ernst-Moritz-Arndt-University, Greifswald, Germany
| | - Johannes Huebner
- Center for Infectious Disease and Travel Medicine, University Medical Center Freiburg, Freiburg, Germany
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, Munich, Germany
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Scharrig E, Carestia A, Ferrer MF, Cédola M, Pretre G, Drut R, Picardeau M, Schattner M, Gómez RM. Neutrophil Extracellular Traps are Involved in the Innate Immune Response to Infection with Leptospira. PLoS Negl Trop Dis 2015; 9:e0003927. [PMID: 26161745 PMCID: PMC4498591 DOI: 10.1371/journal.pntd.0003927] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/20/2015] [Indexed: 12/30/2022] Open
Abstract
NETosis is a process by which neutrophils extrude their DNA together with bactericidal proteins that trap and/or kill pathogens. In the present study, we evaluated the ability of Leptospira spp. to induce NETosis using human ex vivo and murine in vivo models. Microscopy and fluorometric studies showed that incubation of human neutrophils with Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 (LIC) resulted in the release of DNA extracellular traps (NETs). The bacteria number, pathogenicity and viability were relevant factors for induction of NETs, but bacteria motility was not. Entrapment of LIC in the NETs resulted in LIC death; however, pathogenic but not saprophytic Leptospira sp. exerted nuclease activity and degraded DNA. Mice infected with LIC showed circulating NETs after 2 days post-infection (dpi). Depletion of neutrophils with mAb1A8 significantly reduced the amount of intravascular NETs in LIC-infected mice, increasing bacteremia at 3 dpi. Although there was a low bacterial burden, scarce neutrophils and an absence of inflammation in the early stages of infection in the kidney and liver, at the beginning of the leptospiruric phase, the bacterial burden was significantly higher in kidneys of neutrophil-depleted-mice compared to non-depleted and infected mice. Surprisingly, interstitial nephritis was of similar intensity in both groups of infected mice. Taken together, these data suggest that LIC triggers NETs, and that the intravascular formation of these DNA traps appears to be critical not only to prevent early leptospiral dissemination but also to preclude further bacterial burden. Neutrophils extracellular traps (NETs) are a relatively novel pathogen-killing mechanism for extracellular microbes independent of phagocytic uptake and degranulation. Although it was originally proposed that NETs are formed exclusively in tissues at sites of infection, NETs have also been found within blood vessels where they ensnare microbes in circulation during sepsis. Leptospirosis is a global zoonosis that has become prevalent in slum areas, where its diagnosis and treatment may be overlooked. Here, for the first time, we characterized NETs formation as a result of Leptospira spp. stimulus. We also showed that mice lacking neutrophils exhibit early reduced levels of circulating NETs, but higher bacteremia, a fact that was later associated with higher bacterial burden in kidney. The present results demonstrate that Leptospira spp. can trigger NET formation and that this innate immune mechanism can play a role in the pathogenesis of leptospirosis.
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Affiliation(s)
- Emilia Scharrig
- Laboratory of Animal Viruses, Institute of Biotechnology and Molecular Biology, CCT-La Plata, CONICET-UNLP, Buenos Aires, Argentina
| | - Agostina Carestia
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine, CONICET-National Academy of Medicine, Buenos Aires, Argentina
| | - María F. Ferrer
- Laboratory of Animal Viruses, Institute of Biotechnology and Molecular Biology, CCT-La Plata, CONICET-UNLP, Buenos Aires, Argentina
| | - Maia Cédola
- Laboratory of Animal Viruses, Institute of Biotechnology and Molecular Biology, CCT-La Plata, CONICET-UNLP, Buenos Aires, Argentina
| | - Gabriela Pretre
- Laboratory of Animal Viruses, Institute of Biotechnology and Molecular Biology, CCT-La Plata, CONICET-UNLP, Buenos Aires, Argentina
| | - Ricardo Drut
- Division of Pathology, Children Hospital “Superiora Sor María Ludovica”, La Plata, Argentina
- Cátedra de Patología “A”, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | | | - Mirta Schattner
- Laboratory of Experimental Thrombosis, Institute of Experimental Medicine, CONICET-National Academy of Medicine, Buenos Aires, Argentina
- * E-mail: (MS); (RMG)
| | - Ricardo M. Gómez
- Laboratory of Animal Viruses, Institute of Biotechnology and Molecular Biology, CCT-La Plata, CONICET-UNLP, Buenos Aires, Argentina
- * E-mail: (MS); (RMG)
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Kodali S, Vinogradov E, Lin F, Khoury N, Hao L, Pavliak V, Jones CH, Laverde D, Huebner J, Jansen KU, Anderson AS, Donald RGK. A Vaccine Approach for the Prevention of Infections by Multidrug-resistant Enterococcus faecium. J Biol Chem 2015; 290:19512-26. [PMID: 26109072 DOI: 10.1074/jbc.m115.655852] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Indexed: 12/19/2022] Open
Abstract
The incidence of multidrug-resistant Enterococcus faecium hospital infections has been steadily increasing. With the goal of discovering new vaccine antigens, we systematically fractionated and purified four distinct surface carbohydrates from E. faecium endocarditis isolate Tx16, shown previously to be resistant to phagocytosis in the presence of human serum. The two most abundant polysaccharides consist of novel branched heteroglycan repeating units that include signature sugars altruronic acid and legionaminic acid, respectively. A minor high molecular weight polysaccharide component was recognized as the fructose homopolymer levan, and a glucosylated lipoteichoic acid (LTA) was identified in a micellar fraction. The polysaccharides were conjugated to the CRM197 carrier protein, and the resulting glycoconjugates were used to immunize rabbits. Rabbit immune sera were evaluated for their ability to kill Tx16 in opsonophagocytic assays and in a mouse passive protection infection model. Although antibodies raised against levan failed to mediate opsonophagocytic killing, the other glycoconjugates induced effective opsonic antibodies, with the altruronic acid-containing polysaccharide antisera showing the greatest opsonophagocytic assay activity. Antibodies directed against either novel heteroglycan or the LTA reduced bacterial load in mouse liver or kidney tissue. To assess antigen prevalence, we screened a diverse collection of blood isolates (n = 101) with antibodies to the polysaccharides. LTA was detected on the surface of 80% of the strains, and antigens recognized by antibodies to the two major heteroglycans were co-expressed on 63% of these clinical isolates. Collectively, these results represent the first steps toward identifying components of a glycoconjugate vaccine to prevent E. faecium infection.
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Affiliation(s)
- Srinivas Kodali
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654
| | | | - Fiona Lin
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654
| | - Nancy Khoury
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654
| | - Li Hao
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654
| | - Vilo Pavliak
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654
| | - C Hal Jones
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654
| | - Diana Laverde
- the Division of Infectious Diseases, Department of Medicine, University Hospital, Hugstetter Strasse 55, 79106 Freiburg, Germany, and
| | - Johannes Huebner
- the Division of Infectious Diseases, Department of Medicine, University Hospital, Hugstetter Strasse 55, 79106 Freiburg, Germany, and the Department of Pediatrics, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, Lindwurmstrasse 4, 80338 Munich, Germany
| | - Kathrin U Jansen
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654
| | | | - Robert G K Donald
- From Pfizer Vaccine Research and Early Development, Pearl River, New York 10654,
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Muller C, Cacaci M, Sauvageot N, Sanguinetti M, Rattei T, Eder T, Giard JC, Kalinowski J, Hain T, Hartke A. The Intraperitoneal Transcriptome of the Opportunistic Pathogen Enterococcus faecalis in Mice. PLoS One 2015; 10:e0126143. [PMID: 25978463 PMCID: PMC4433114 DOI: 10.1371/journal.pone.0126143] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/29/2015] [Indexed: 01/22/2023] Open
Abstract
Enterococcus faecalis is a Gram-positive lactic acid intestinal opportunistic bacterium with virulence potential. For a better understanding of the adapation of this bacterium to the host conditions, we performed a transcriptome analysis of bacteria isolated from an infection site (mouse peritonitis) by RNA-sequencing. We identified a total of 211 genes with significantly higher transcript levels and 157 repressed genes. Our in vivo gene expression database reflects well the infection process since genes encoding important virulence factors like cytolysin, gelatinase or aggregation substance as well as stress response proteins, are significantly induced. Genes encoding metabolic activities are the second most abundant in vivo induced genes demonstrating that the bacteria are metabolically active and adapt to the special nutrient conditions of the host. α- and β- glucosides seem to be important substrates for E. faecalis inside the host. Compared to laboratory conditions, the flux through the upper part of glycolysis seems to be reduced and more carbon may enter the pentose phosphate pathway. This may reflect the need of the bacteria under infection conditions to produce more reducing power for biosynthesis. Another important substrate is certainly glycerol since both pathways of glycerol catabolism are strongly induced. Strongly in vivo induced genes should be important for the infection process. This assumption has been verified in a virulence test using well characterized mutants affected in glycerol metabolism. This showed indeed that mutants unable to metabolize this sugar alcohol are affected in organ colonisation in a mouse model.
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Affiliation(s)
- Cécile Muller
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
- * E-mail: (AH); (CM)
| | - Margherita Cacaci
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
- Institute of Microbiology, Catholic University of Sacred Heart, 00168, Rome, Italy
| | - Nicolas Sauvageot
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
| | - Maurizio Sanguinetti
- Institute of Microbiology, Catholic University of Sacred Heart, 00168, Rome, Italy
| | - Thomas Rattei
- CUBE-Division for Computational Systems Biology, Dept. of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Thomas Eder
- CUBE-Division for Computational Systems Biology, Dept. of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Jean-Christophe Giard
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, 33594 Bielefeld, Germany
| | - Torsten Hain
- Institute of Medicine Microbiology, Gießen University, 35392 Gießen, Germany
| | - Axel Hartke
- U2RM-Stress and Virulence, University of Caen Basse-Normandie, EA4655, 14032 Caen, France
- * E-mail: (AH); (CM)
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Theobaldo MC, Llimona F, Petroni RC, Rios ECS, Velasco IT, Soriano FG. Hypertonic saline solution drives neutrophil from bystander organ to infectious site in polymicrobial sepsis: a cecal ligation and puncture model. PLoS One 2013; 8:e74369. [PMID: 24069301 PMCID: PMC3775765 DOI: 10.1371/journal.pone.0074369] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 08/04/2013] [Indexed: 12/18/2022] Open
Abstract
The effects of hypertonic saline solution (HSS) have been shown in several animal models of ischemia and shock. Literature has shown potential benefits of HSS modulating inflammatory response after sepsis in an animal model. We studied the HSS effects in sepsis through cecal ligation and puncture (CLP) in Balb-C mice. Groups studied: 1- CLP without treatment (CLP-C); 2- CLP treated with normal saline solution NaCl 0.9% – 34 ml/Kg (CLP-S); 3- CLP treated with HSS NaCl 7.5% – 4 ml/Kg (CLP-H); and 4- group (Basal) without no CLP or treatment. Volume infusion was always applied 30 min after CLP. Lung and peritoneal lavage were harvested after 6h and 24h of CLP to analyze cytokines amount, oxide nitric, lipid peroxidation and neutrophil infiltration. Neutrophil infiltration, ICAM-1, CXCR-2, and CXCL-1 in lung were reduced by HSS (CLP-H) compared to CLP-C or CLP-S. Neutrophil in peritoneal lavage was increased in 24h with HSS (CLP-H) compared to CLP and CLP-S. Peritoneal CXCR-2 was increased in CLP-C and CLP-S but presented a lower increase with HSS (CLP-H) after 6 hours. GRK-2 presented difference among the groups at 24 h, showing a profile similar to neutrophil infiltration. Pro-inflammatory cytokines (TNF-α and IL-6) were reduced by HSS treatment; CLP-S increased TNF-α. IL-10 was increased in lung tissue by the HSS treatment. The oxidative stress (TBARS and nitric oxide biochemistry markers) was reduced with HSS. Animal survival was 33.3% in CLP-C group, 46.6% in CLP-S group and 60% in the CLP-H group after the sixth day. The HSS protects the animal against sepsis. Our results suggest that the volume replacement modulate pro and anti-inflammatory mediators of an inflammatory response, but HSS presented a more effective and potent effect.
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Affiliation(s)
| | - Flavia Llimona
- Emergency of Medicine Division-Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Ricardo Costa Petroni
- Emergency of Medicine Division-Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | | | - Irineu Tadeu Velasco
- Emergency of Medicine Division-Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Francisco Garcia Soriano
- Emergency of Medicine Division-Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
- * E-mail:
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Abstract
UNLABELLED Nosocomial outbreaks of vancomycin-resistant Enterococcus faecium (VREfm) are thought to occur by transmission of VREfm between patients, predicting that infection control interventions will limit cross-transmission. Despite implementation of such strategies, the incidence of VREfm infections continues to rise. We aimed to use genomics to better understand the epidemiology of E. faecium within a large hospital and investigate the reasons for failure of infection control strategies. Whole-genome sequencing was performed on 61 E. faecium (36 VREfm) isolates, predominately from blood cultures collected at a single hospital between 1998 and 2009, and on five vanB-positive anaerobic commensal bacteria isolated from human feces. Phylogenomic analysis and precise mapping of the vanB gene, which contains the Tn1549 transposon, showed that at least 18 of the 36 VREfm isolates had acquired the transposon via independent insertion events, indicating de novo generation of VREfm rather than cross-transmission. Furthermore, Tn1549 sequences found in 15 of the 36 VREfm isolates were the same as the Tn1549 sequence from one of the gut anaerobes. National and international comparator E. faecium isolates were phylogenetically interspersed with isolates from our hospital, suggesting that our findings might be globally representative. These data demonstrate that VREfm generation within a patient is common, presumably occurring in the human bowel during antibiotic therapy, and help explain our inability to reduce VREfm infections. A recommendation from our findings is that infection control practices should include screening patients for specific hospital clones of vancomycin-susceptible E. faecium rather than just VREfm. IMPORTANCE Enterococcus faecium is an increasingly important human pathogen causing predominantly antibiotic-resistant infections in hospitalized patients. Large amounts of health care funding are spent trying to control antibiotic-resistant bacteria in hospitals globally, yet in many institutions around the world, vancomycin-resistant E. faecium (VREfm) infections continue to rise. The new findings from this study help explain the failures of our current approaches to controlling vanB VREfm in health care institutions. Given the importance of this bacterium as a cause of hospital-acquired infections and the difficulties faced by infection control units in trying to prevent colonization in their institutions, the novel findings from this study provide evidence that a new approach to controlling VREfm in hospitals is required. In particular, more attention should be given to understanding the epidemiology of hospital-adapted vancomycin-susceptible E. faecium, and patients at higher risk for de novo generation of VREfm need to be identified and optimally managed.
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Hasan SA, Eksteen B, Reid D, Paine HV, Alansary A, Johannson K, Gwozd C, Goring KAR, Vo T, Proud D, Kelly MM. Role of IL-17A and neutrophils in fibrosis in experimental hypersensitivity pneumonitis. J Allergy Clin Immunol 2013; 131:1663-73. [DOI: 10.1016/j.jaci.2013.01.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 11/15/2012] [Accepted: 01/15/2013] [Indexed: 11/25/2022]
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Enterococcus faecalis overcomes foreign body-mediated inflammation to establish urinary tract infections. Infect Immun 2012; 81:329-39. [PMID: 23132492 DOI: 10.1128/iai.00856-12] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Urinary catheterization elicits major histological and immunological changes that render the bladder susceptible to microbial invasion, colonization, and dissemination. However, it is not understood how catheters induce these changes, how these changes act to promote infection, or whether they may have any protective benefit. In the present study, we examined how catheter-associated inflammation impacts infection by Enterococcus faecalis, a leading cause of catheter-associated urinary tract infection (CAUTI), a source of significant societal and clinical challenges. Using a recently optimized murine model of foreign body-associated UTI, we found that the implanted catheter itself was the primary inducer of inflammation. In the absence of the silicone tubing implant, E. faecalis induced only minimal inflammation and was rapidly cleared from the bladder. The catheter-induced inflammation was only minimally altered by subsequent enterococcal infection and was not suppressed by inhibitors of the neurogenic pathway and only partially by dexamethasone. Despite the robust inflammatory response induced by urinary implantation, E. faecalis produced biofilm and high bladder titers in these animals. Induction of inflammation in the absence of an implanted catheter failed to promote infection, suggesting that the presence of the catheter itself is essential for E. faecalis persistence in the bladder. Immunosuppression prior to urinary catheterization enhanced E. faecalis colonization, suggesting that implant-mediated inflammation contributes to the control of enterococcal infection. Thus, this study underscores the need for novel strategies against CAUTIs that seek to reduce the deleterious effects of implant-mediated inflammation on bladder homeostasis while maintaining an active immune response that effectively limits bacterial invaders.
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Efficacy of OH-CATH30 and its analogs against drug-resistant bacteria in vitro and in mouse models. Antimicrob Agents Chemother 2012; 56:3309-17. [PMID: 22491685 DOI: 10.1128/aac.06304-11] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Antimicrobial peptides (AMPs) have been considered alternatives to conventional antibiotics for drug-resistant bacterial infections. However, their comparatively high toxicity toward eukaryotic cells and poor efficacy in vivo hamper their clinical application. OH-CATH30, a novel cathelicidin peptide deduced from the king cobra, possesses potent antibacterial activity in vitro. The objective of this study is to evaluate the efficacy of OH-CATH30 and its analog OH-CM6 against drug-resistant bacteria in vitro and in vivo. The MICs of OH-CATH30 and OH-CM6 ranged from 1.56 to 12.5 μg/ml against drug-resistant clinical isolates of several pathogenic species, including Escherichia coli, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus. The MICs of OH-CATH30 and OH-CM6 were slightly altered in the presence of 25% human serum. OH-CATH30 and OH-CM6 killed E. coli quickly (within 60 min) by disrupting the bacterial cytoplasmic membrane. Importantly, the 50% lethal doses (LD(50)) of OH-CATH30 and OH-CM6 in mice following intraperitoneal (i.p.) injection were 120 mg/kg of body weight and 100 mg/kg, respectively, and no death was observed at any dose up to 160 mg/kg following subcutaneous (s.c.) injection. Moreover, 10 mg/kg OH-CATH30 or OH-CM6 significantly decreased the bacterial counts as well as the inflammatory response in a mouse thigh infection model and rescued infected mice in a bacteremia model induced by drug-resistant E. coli. Taken together, our findings demonstrate that the natural cathelicidin peptide OH-CATH30 and its analogs exhibit relatively low toxicity and potent efficacy in mouse models, indicating that they may have therapeutic potential against the systemic infections caused by drug-resistant bacteria.
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Tsuchiya T, Nakao N, Yamamoto S, Hirai Y, Miyamoto K, Tsujibo H. NK1.1+ cells regulate neutrophil migration in mice with Acinetobacter baumannii pneumonia. Microbiol Immunol 2012; 56:107-16. [DOI: 10.1111/j.1348-0421.2011.00402.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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36
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Thompson AL, Johnson BT, Sempowski GD, Gunn MD, Hou B, DeFranco AL, Staats HF. Maximal adjuvant activity of nasally delivered IL-1α requires adjuvant-responsive CD11c(+) cells and does not correlate with adjuvant-induced in vivo cytokine production. THE JOURNAL OF IMMUNOLOGY 2012; 188:2834-46. [PMID: 22345651 DOI: 10.4049/jimmunol.1100254] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
IL-1 has been shown to have strong mucosal adjuvant activities, but little is known about its mechanism of action. We vaccinated IL-1R1 bone marrow (BM) chimeric mice to determine whether IL-1R1 expression on stromal cells or hematopoietic cells was sufficient for the maximal adjuvant activity of nasally delivered IL-1α as determined by the acute induction of cytokine responses and induction of Bacillus anthracis lethal factor (LF)-specific adaptive immunity. Cytokine and chemokine responses induced by vaccination with IL-1α were predominantly derived from the stromal cell compartment and included G-CSF, IL-6, IL-13, MCP-1, and keratinocyte chemoattractant. Nasal vaccination of Il1r1(-/-) (knock-out [KO]) mice given wild-type (WT) BM (WT→KO) and WT→WT mice with LF + IL-1α induced maximal adaptive immune responses, whereas vaccination of WT mice given Il1r1(-/-) BM (KO→WT) resulted in significantly decreased production of LF-specific serum IgG, IgG subclasses, lethal toxin-neutralizing Abs, and mucosal IgA compared with WT→KO and WT→WT mice (p < 0.05). IL-1α adjuvant activity was not dependent on mast cells. However, the ability of IL-1α to induce serum LF-specific IgG2c and lethal toxin-neutralizing Abs was significantly impaired in CD11c-Myd88(-/-) mice when compared with WT mice (p < 0.05). Our results suggest that CD11c(+) cells must be directly activated by nasally administered IL-1α for maximal adjuvant activity and that, although stromal cells are required for maximal adjuvant-induced cytokine production, the adjuvant-induced stromal cell cytokine responses are not required for effective induction of adaptive immunity.
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Affiliation(s)
- Afton L Thompson
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
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Bao Y, Cao X. Revisiting the protective and pathogenic roles of neutrophils: Ly-6G is key! Eur J Immunol 2011; 41:2535-8. [PMID: 21952813 DOI: 10.1002/eji.201141979] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The physiological and pathophysiological roles of neutrophils in immune homeostasis and disease have been investigated extensively by way of anti-Gr-1 mAb-mediated depletion experiments; however, the ability of the anti-Gr-1 mAb to specifically deplete neutrophils has long been questioned and it is now known that this mAb, which binds Ly6C and Ly6G, is also able to deplete monocytes and subsets of CD8(+) T cells. This, therefore, casts doubt on the previous conclusions regarding the role of neutrophils drawn from studies using this mAb. Another mAb, which targets Ly6G only, has recently been shown to deplete neutrophils specifically and a study by Carr et al. (Eur. J. Immunol. 2011. 41: 2666-2676) in this issue of the European Journal of Immunology utilizes this Ly-6G mAb to reveal the precise role of neutrophils during Listeria monocytogenes (LM) infection. Carr et al. find that monocytes/macrophages, rather than neutrophils, dominate the initial control of LM growth in the spleen, whereas neutrophils in the liver are key for host resistance to LM infection. These data suggest that the previously reported protective or pathogenic roles of neutrophils in disease models need to be reconsidered through anti-Ly6G mAb-mediated depletion experiments.
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Affiliation(s)
- Yan Bao
- Department of Laboratory Diagnostics, Changzheng Hospital, Second Military Medical University, Shanghai, P R China.
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Foster N, Berndt A, Lalmanach AC, Methner U, Pasquali P, Rychlik I, Velge P, Zhou X, Barrow P. Emergency and therapeutic vaccination--is stimulating innate immunity an option? Res Vet Sci 2011; 93:7-12. [PMID: 22015261 DOI: 10.1016/j.rvsc.2011.05.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 05/08/2011] [Accepted: 05/24/2011] [Indexed: 01/22/2023]
Abstract
There is increasing evidence that activation of innate immunity, in animals and man, by live vaccines, sub-unit vaccines or synthetic or non-synthetic stimulants can induce a profound and rapidly induced resistance to pathogens, including infectious agents that are unrelated to the stimulating antigen or agent. We review the evidence for this phenomenon and present the proposition that this approach might be used to stimulate immunity during the life of the animal when susceptibility to infection is high and when normal vaccination procedures may be inappropriate.
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Affiliation(s)
- N Foster
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK
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Banerjee A, Kim BJ, Carmona EM, Cutting AS, Gurney MA, Carlos C, Feuer R, Prasadarao NV, Doran KS. Bacterial Pili exploit integrin machinery to promote immune activation and efficient blood-brain barrier penetration. Nat Commun 2011; 2:462. [PMID: 21897373 PMCID: PMC3195231 DOI: 10.1038/ncomms1474] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 08/10/2011] [Indexed: 12/25/2022] Open
Abstract
Group B Streptococcus (GBS) is the leading cause of meningitis in newborn infants. Bacterial cell surface appendages, known as pili, have been recently described in streptococcal pathogens, including GBS. The pilus tip adhesin, PilA, contributes to GBS adherence to blood-brain barrier (BBB) endothelium; however, the host receptor and the contribution of PilA in central nervous system (CNS) disease pathogenesis are unknown. Here we show that PilA binds collagen, which promotes GBS interaction with the α₂β₁ integrin resulting in activation of host chemokine expression and neutrophil recruitment during infection. Mice infected with the PilA-deficient mutant exhibit delayed mortality, a decrease in neutrophil infiltration and bacterial CNS dissemination. We find that PilA-mediated virulence is dependent on neutrophil influx as neutrophil depletion results in a decrease in BBB permeability and GBS-BBB penetration. Our results suggest that the bacterial pilus, specifically the PilA adhesin, has a dual role in immune activation and bacterial entry into the CNS.
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Affiliation(s)
- Anirban Banerjee
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
| | - Brandon J. Kim
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
- These authors contributed equally to this work
| | - Ellese M. Carmona
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
- These authors contributed equally to this work
| | - Andrew S. Cutting
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
| | - Michael A. Gurney
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
| | - Chris Carlos
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
| | - Ralph Feuer
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
| | - Nemani V. Prasadarao
- Division of Infectious Diseases, Department of Pediatrics, Childrens Hospital Los Angeles and University of Southern California Keck School of Medicine, Los Angeles, California 90027, USA
| | - Kelly S. Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA
- Department of Pediatrics, University of California–San Diego School of Medicine, La Jolla, California 92093, USA
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Abdulla A, Awla D, Thorlacius H, Regnér S. Role of neutrophils in the activation of trypsinogen in severe acute pancreatitis. J Leukoc Biol 2011; 90:975-82. [PMID: 21810937 DOI: 10.1189/jlb.0411195] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The relationship between inflammation and proteolytic activation in pancreatitis is an unresolved issue in pancreatology. The purpose of this study was to define the influence of neutrophils on trypsinogen activation in severe AP. Pancreatitis was induced by infusion of taurocholate into the pancreatic duct in C57BL/6 mice. For neutrophil depletion, an anti-Gr-1 antibody was administered before pancreatitis induction. Administration of the anti-Gr-1 antibody reduced circulating neutrophils by 97%. Pancreatic TAP and serum amylase levels increased 2 h and 24 h after induction of pancreatitis. Neutrophil depletion reduced pancreatic TAP and serum amylase levels at 24 h but not at 2 h after pancreatitis induction. Pancreatic MPO and infiltration of neutrophils, as well as MIP-2 levels, were increased 24 h after taurocholate infusion. Two hours after taurocholate administration, no significant pancreatic infiltration of neutrophils was observed. Injection of the anti-Gr-1 antibody abolished MPO activity, neutrophil accumulation, and MIP-2 levels, as well as acinar cell necrosis, hemorrhage, and edema in the pancreas at 24 h. Moreover, taurocholate-provoked tissue damage and MPO activity in the lung were normalized by neutrophil depletion. Intravital fluorescence microscopy revealed a 97% reduction of leukocytes in the pancreatic microcirculation after administration of the anti-Gr-1 antibody. Our data demonstrate that initial trypsinogen activation is independent of neutrophils, whereas later activation is dependent on neutrophils in the pancreas. Neutrophils are critical in mediating pancreatic and lung tissue damage in severe AP.
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Affiliation(s)
- Aree Abdulla
- Department of Surgery, Clinical Sciences, Lund University, Malmö, Sweden
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Immunomodulatory and protective roles of quorum-sensing signaling molecules N-acyl homoserine lactones during infection of mice with Aeromonas hydrophila. Infect Immun 2011; 79:2646-57. [PMID: 21536794 DOI: 10.1128/iai.00096-11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Aeromonas hydrophila leads to both intestinal and extraintestinal infections in animals and humans, and the underlying mechanisms leading to mortality are largely unknown. By using a septicemic mouse model of infection, we showed that animals challenged with A. hydrophila die because of kidney and liver damage, hypoglycemia, and thrombocytopenia. Pretreatment of animals with quorum-sensing-associated signaling molecules N-acyl homoserine lactones (AHLs), such as butanoyl and hexanoyl homoserine lactones (C(4)- and C(6)-HSLs), as well as N-3-oxododecanoyl (3-oxo-C(12))-HSL, prevented clinical sequelae, resulting in increased survivability of mice. Since little is known as to how different AHLs modulate the immune response during infection, we treated mice with the above AHLs prior to lethal A. hydrophila infection. When we compared results in such animals to those in controls, the treated animals exhibited a significantly reduced bacterial load in the blood and other mouse organs, as well as various levels of cytokines/chemokines. Importantly, neutrophil numbers were significantly elevated in the blood of C(6)-HSL-treated mice compared to those in animals given phosphate-buffered saline and then infected with the bacteria. These findings coincided with the fact that neutropenic animals were more susceptible to A. hydrophila infection than normal mice. Our data suggested that neutrophils quickly cleared bacteria by either phagocytosis or possibly another mechanism(s) during infection. In a parallel study, we indeed showed that other predominant immune cells inflicted during A. hydrophila infections, such as murine macrophages, when they were pretreated with AHLs, rapidly phagocytosed bacteria, whereas untreated cells phagocytosed fewer bacteria. This study is the first to report that AHL pretreatment modulates the innate immune response in mice and enhances their survivability during A. hydrophila infection.
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Abstract
Enterococcus faecalis and Enterococcus faecium have emerged as multi-resistant nosocomial pathogens in immunocompromised and critically ill patients. Multi-resistant strains have acquired virulence genes resulting in hospital-adapted clones. The following review summarizes several proteins and carbohydrate- or glycoconjugates that have been identified as putative virulence factors involved in the pathogenesis of enterococcal infections and may be used as targets for alternative therapies. Several studies describing the host immune response against enterococci are also summarized.
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Affiliation(s)
- I G Sava
- Division of Infectious Diseases, Department of Medicine, University Medical Center Freiburg, Germany
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Veninga H, de Groot DM, McCloskey N, Owens BM, Dessing MC, Verbeek JS, Nourshargh S, van Eenennaam H, Boots AM, Hamann J. CD97 antibody depletes granulocytes in mice under conditions of acute inflammation via a Fc receptor-dependent mechanism. J Leukoc Biol 2010; 89:413-21. [DOI: 10.1189/jlb.0510280] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Ocuin LM, Bamboat ZM, Balachandran VP, Cavnar MJ, Obaid H, Plitas G, DeMatteo RP. Neutrophil IL-10 suppresses peritoneal inflammatory monocytes during polymicrobial sepsis. J Leukoc Biol 2010; 89:423-32. [PMID: 21106642 DOI: 10.1189/jlb.0810479] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Septic peritonitis remains a major cause of death. Neutrophils and inflammatory monocytes are principal components of the innate immune system and are essential for defense against a range of microbial pathogens. Their role and interaction in polymicrobial sepsis have not been defined clearly. Using a murine model of CLP to induce moderate sepsis, we found that neutrophil depletion did not alter survival, whereas depletion of neutrophils and inflammatory monocytes markedly reduced survival. After neutrophil depletion, inflammatory monocytes had greater phagocytic capacity and oxidative burst, and increased expression of costimulatory molecules, TNF, and iNOS. Notably, peritoneal neutrophils produced IL-10 following CLP. Adoptive i.p. transfer of WT but not IL-10(-/-) neutrophils into septic mice reduced monocyte expression of TNF. In vitro experiments confirmed that monocyte suppression was mediated by neutrophil-derived IL-10. Thus, during septic peritonitis, neutrophils suppress peritoneal inflammatory monocytes through IL-10 and are dispensable for survival.
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Affiliation(s)
- Lee M Ocuin
- Hepatopancreatobiliary Service, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
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Gröbner S, Fritz E, Schoch F, Schaller M, Berger AC, Bitzer M, Autenrieth IB. Lysozyme activates Enterococcus faecium to induce necrotic cell death in macrophages. Cell Mol Life Sci 2010; 67:3331-44. [PMID: 20458518 PMCID: PMC11115887 DOI: 10.1007/s00018-010-0384-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 03/31/2010] [Accepted: 04/22/2010] [Indexed: 11/29/2022]
Abstract
Enterococci are commensal organisms in the alimentary tract. However, they can cause a variety of life-threatening infections, especially in nosocomial settings. We hypothesized that induction of cell death might enable these facultative pathogenic bacteria to evade the innate immune response and to cause infections of their host. We demonstrate that E. faecium when exposed to lysozyme induces cell death in macrophages in vitro and in vivo. Flow cytometric analyses of J774A.1 macrophages infected with E. faecium revealed loss of cell membrane integrity indicated by uptake of propidium iodide and decrease of the inner mitochondrial transmembrane potential DeltaPsi(m). Inhibition of caspases, treatment of macrophages with cytochalasin D, or rifampicin did not prevent cells from dying, suggesting cell death mechanisms that are independent of caspase activation, bacterial uptake, and intracellular bacterial replication. Characteristics of necrotic cell death were demonstrated by both lack of procaspase 3 activation and cell shrinkage, electron microscopy, and release of lactate dehydrogenase. Pretreatment of E. faecium with lysozyme and subsequently with broad spectrum protease considerably reduced cell death, suggesting that a bacterial surface protein is causative for cell death induction. Moreover, in a mouse peritonitis model we demonstrated that E. faecium induces cell death of peritoneal macrophages in vivo. Altogether, our results show that enterococci, under specific conditions such as exposure to lysozyme, induce necrotic cell death in macrophages, which might contribute to disseminated infections by these facultative pathogenic bacteria.
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Affiliation(s)
- Sabine Gröbner
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Elfriede-Aulhorn-Str. 6, 72076 Tübingen, Germany.
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Interleukin-7 (IL-7) treatment accelerates neutrophil recruitment through gamma delta T-cell IL-17 production in a murine model of sepsis. Infect Immun 2010; 78:4714-22. [PMID: 20823197 DOI: 10.1128/iai.00456-10] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The sepsis syndrome represents an improper immune response to infection and is associated with unacceptably high rates of mortality and morbidity. The interactions between T cells and the innate immune system while combating sepsis are poorly understood. In this report, we observed that treatment with the potent, antiapoptotic cytokine interleukin-7 (IL-7) accelerated neutrophil recruitment and improved bacterial clearance. We first determined that T cells were necessary for the previously observed IL-7-mediated enhanced survival. Next, IL-7 increased Bcl-2 expression in T cells isolated from septic mice as early as 3 h following treatment. This treatment resulted in increased gamma interferon (IFN-γ) and IP-10 production within the septic peritoneum together with local and systemic increases of IL-17 in IL-7-treated mice. We further demonstrate that the increase in IL-17 was largely due to increased recruitment and production by γδ T cells, which express CXCR3. Consistent with increased IL-17 production, IL-7 treatment increased CXCL1/KC production, neutrophil recruitment, and bacterial clearance. Significantly, end-organ tissue injury was not significantly different between vehicle- and IL-7-treated mice. Collectively, these data illustrate that IL-7 can mediate the cross talk between Th1 and Th17 lymphocytes during sepsis such that neutrophil recruitment and bacterial clearance is improved while early tissue injury is not increased. All together, these observations may underlay novel potential therapeutic targets to improve the host immune response to sepsis.
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Fabrizio K, Manix C, Tian H, van Rooijen N, Pirofski LA. The efficacy of pneumococcal capsular polysaccharide-specific antibodies to serotype 3 Streptococcus pneumoniae requires macrophages. Vaccine 2010; 28:7542-50. [PMID: 20800700 DOI: 10.1016/j.vaccine.2010.08.061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 08/01/2010] [Accepted: 08/12/2010] [Indexed: 10/19/2022]
Abstract
The efficacy of antibody immunity against Streptococcus pneumoniae stems from the ability of opsonic, serotype (ST)-specific antibodies to pneumococcal capsular polysaccharide (PPS) to facilitate killing of the homologous ST by host phagocytes. However, PPS-specific antibodies have been identified that are protective in mice, but do not promote opsonic killing in vitro, raising the question of how they mediate protection in vivo. To probe this question, we investigated the dependence of antibody efficacy against lethal systemic (intraperitoneal, i.p.) infection with Streptococcus pneumoniae serotype 3 (ST3) on macrophages and neutrophils for the following PPS3-specific monoclonal antibodies (MAbs) in survival experiments in mice using a non-opsonic human IgM (A7), a non-opsonic mouse IgG1 (1E2) and an opsonic mouse IgG1 (5F6). The survival of A7- and PPS3-specific and isotype control MAb-treated neutrophil-depleted and neutrophil-sufficient and macrophage-depleted and macrophage-sufficient mice were determined after i.p. challenge with ST3 strains 6303 and WU2. Neutrophils were dispensable for A7 and the mouse MAbs to mediate protection in this model, but macrophages were required for the efficacy of A7 and optimal mouse MAb-mediated protection. For A7-treated mice, macrophage-depleted mice had higher blood CFU, cytokines and peripheral neutrophil levels than macrophage-sufficient mice, and macrophage-sufficient mice had lower tissue bacterial burdens than control MAb-treated mice. These findings demonstrate that macrophages contribute to opsonic and non-opsonic PPS3-specific MAb-mediated protection against ST3 infection by enhancing bacterial clearance and suggest that neutrophils do not compensate for the absence of macrophages in the model used in this study.
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Affiliation(s)
- Kevin Fabrizio
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Kumar A, Gao N, Standiford TJ, Gallo RL, Yu FSX. Topical flagellin protects the injured corneas from Pseudomonas aeruginosa infection. Microbes Infect 2010; 12:978-89. [PMID: 20601077 DOI: 10.1016/j.micinf.2010.06.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 06/15/2010] [Accepted: 06/17/2010] [Indexed: 10/19/2022]
Abstract
Among bacterial pathogens, Pseudomonas (P.) aeruginosa infection is the most sight threatening. The corneal innate immune responses are key mediators of the host's defense to P. aeruginosa. Using a mouse model of Pseudomonas keratitis, we evaluated the protective effects of topical application of flagellin, a ligand for Toll-Like receptor 5 (TLR5), on the development of Pseudomonas keratitis and elucidated the underlying mechanisms. Topical application of purified flagellin 6 and 24 h prior to P. aeruginosa inoculation on injured mouse corneas significantly attenuated clinical symptoms of P. aeruginosa keratitis, decreased bacterial burden, and suppressed infection induced inflammation in the B6 mouse cornea. Topical application of flagellin on wounded cornea induced PMN infiltration and markedly upregulated cathelicidin-related antimicrobial peptide (CRAMP) expression. In PMN depleted mice, flagellin promoted bacterial clearance in the cornea compared to that of the PBS treated mice, but was unable to prevent corneal perforation and systemic bacterial dissemination and sepses. Deletion of CRAMP increased corneal susceptibility to P. aeruginosa and abolished flagellin-induced protection in B6 mice. Our findings illustrate the profound protective effect of flagellin on the cornea innate defense, a response that can be exploited for prophylactic purposes to prevent contact lens associated Pseudomonas keratitis.
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Affiliation(s)
- Ashok Kumar
- Departments of Ophthalmology and Anatomy & Cell Biology, Kresge Eye Institute, Wayne State University School of Medicine, 4717 St. Antoine, Detroit, MI 48201, USA
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Zimecki M, Artym J, Kocieba M, Weber-Dabrowska B, Borysowski J, Górski A. Effects of prophylactic administration of bacteriophages to immunosuppressed mice infected with Staphylococcus aureus. BMC Microbiol 2009; 9:169. [PMID: 19686585 PMCID: PMC2741470 DOI: 10.1186/1471-2180-9-169] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 08/17/2009] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Bacteriophages can be successfully applied to treat infections caused by antibiotic-resistant bacteria. Until now no attempts have been undertaken to treat infections in immunosuppressed patients with phages. In this work we investigated the prophylactic efficacy of specific bacteriophages in CBA mice treated with cyclophosphamide (CP) and infected with Staphylococcus aureus. RESULTS High numbers of bacterial colony-forming units in the organs as well as elevated tumor necrosis factor and interleukin-6 serum concentrations in CP-treated and S. aureus-infected mice were significantly lowered upon application of phages. The phages markedly increased the percentage of circulating neutrophils and immature cells from the myelocytic and lymphocytic lineages in CP-treated, S. aureus-infected mice as well as of myelocytes and immature neutrophils in the bone marrow. In addition, phages stimulated in such mice generation of specific agglutinins against S. aureus. CONCLUSION Application of specific phages to immunosuppressed mice prior to infection with S. aureus proved very effective, suggesting a potential benefit of phage therapy in immunocompromised patients experiencing bacterial infections.
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Affiliation(s)
- Michał Zimecki
- Institute of Immunology and Experimental Therapy, Polish Academy of Science, Wrocław, Poland.
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