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Zhu X, Du L, Zhang L, Ding L, Xu W, Lin X. The critical role of toll-like receptor 4 in bone remodeling of osteoporosis: from inflammation recognition to immunity. Front Immunol 2024; 15:1333086. [PMID: 38504994 PMCID: PMC10948547 DOI: 10.3389/fimmu.2024.1333086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 02/20/2024] [Indexed: 03/21/2024] Open
Abstract
Osteoporosis is a common chronic metabolic bone disorder. Recently, increasing numbers of studies have demonstrated that Toll-like receptor 4 (TLR4, a receptor located on the surface of osteoclasts and osteoblasts) plays a pivotal role in the development of osteoporosis. Herein, we performed a comprehensive review to summarize the findings from the relevant studies within this topic. Clinical data showed that TLR4 polymorphisms and aberrant TLR4 expression have been associated with the clinical significance of osteoporosis. Mechanistically, dysregulation of osteoblasts and osteoclasts induced by abnormal expression of TLR4 is the main molecular mechanism underlying the pathological processes of osteoporosis, which may be associated with the interactions between TLR4 and NF-κB pathway, proinflammatory effects, ncRNAs, and RUNX2. In vivo and in vitro studies demonstrate that many promising substances or agents (i.e., methionine, dioscin, miR-1906 mimic, artesunate, AEG-1 deletion, patchouli alcohol, and Bacteroides vulgatus) have been able to improve bone metabolism (i.e., inhibits bone resorption and promotes bone formation), which may partially attribute to the inhibition of TLR4 expression. The present review highlights the important role of TLR4 in the clinical significance and the pathogenesis of osteoporosis from the aspects of inflammation and immunity. Future therapeutic strategies targeting TLR4 may provide a new insight for osteoporosis treatment.
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Affiliation(s)
- Xianping Zhu
- Department of Orthopedics, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, Zhejiang, China
| | - Li Du
- Educational Administration Department, Chongqing University Cancer Hospital, Chongqing, China
| | - Lai Zhang
- Department of Orthopedics, Taizhou Municipal Hospital, Taizhou, Zhejiang, China
| | - Lingzhi Ding
- Department of Orthopedics, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, Zhejiang, China
| | - Weifang Xu
- Department of Orthopedics, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, Zhejiang, China
| | - Xuezheng Lin
- Department of Anesthesia Surgery, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, China
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2
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Kim Y, Ban GH, Hong YW, Jeong KC, Bae D, Kim SA. Bacterial profile of pork from production to retail based on high-throughput sequencing. Food Res Int 2024; 176:113745. [PMID: 38163697 DOI: 10.1016/j.foodres.2023.113745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/14/2023] [Accepted: 11/22/2023] [Indexed: 01/03/2024]
Abstract
Pork is a common vehicle for foodborne pathogens, including Salmonella spp. and Yersinia enterocolitica. Cross-contamination can occur at any stage of the pork production chain, from farm to market. In the present study, high-throughput sequencing was used to characterize bacterial profiles and track their changes along the whole supply chain. Tracked meat samples (pig on the farm, carcass in the slaughterhouse, unprocessed carcass and processed meat in the processing plant, and fresh pork at the local retail stores) and their associated environmental samples (e.g., water, floor, feed, feces, and workers' gloves) were collected from sequential stages (n = 96) and subjected to 16S rRNA metataxonomic analyses. At the farm, a total of 652 genera and 146 exclusive genera were identified in animal and environmental samples (pig, drain, floor, fan, and feces). Based on beta diversity analysis, it was demonstrated that the microbial composition of animal samples collected at the same processing step is similar to that of environmental samples (e.g., drain, fan, feces, feed, floor, gloves, knives, tables, and water). All animal and environmental samples from the slaughterhouse were dominated by Acinetobacter (55.37 %). At the processing plant, belly meat and neck meat samples were dominated by Psychrobacter (55.49 %). At the retail level, key bacterial players, which are potential problematic bacteria and important members with a high relative abundance in the samples, included Acinetobacter (8.13 %), Pseudomonas (6.27 %), and Staphylococcus (2.13 %). In addition, the number of confirmed genera varied by more than twice that identified in the processing plant. Source tracking was performed to identify bacterial contamination routes in pork processing. Animal samples, including the processing plant's carcass, the pig from the farm, and the unwashed carcass from the slaughterhouse (77.45 %), along with the processing plant's gloves (5.71 %), were the primary bacterial sources in the final product. The present study provides in-depth knowledge about the bacterial players and contamination points within the pork production chain. Effective control measures are needed to control pathogens and major pollutants at each stage of pork production to improve food safety.
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Affiliation(s)
- Yejin Kim
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, South Korea
| | - Ga-Hee Ban
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, South Korea
| | - Ye Won Hong
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, South Korea
| | | | - Dongryeoul Bae
- Division of Research and Development, TracoWorld Ltd., Gwangmyeong, South Korea
| | - Sun Ae Kim
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, South Korea.
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3
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Yao Y, Chen Q, Zhou H. Virulence Factors and Pathogenicity Mechanisms of Acinetobacter baumannii in Respiratory Infectious Diseases. Antibiotics (Basel) 2023; 12:1749. [PMID: 38136783 PMCID: PMC10740465 DOI: 10.3390/antibiotics12121749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/14/2023] [Accepted: 12/16/2023] [Indexed: 12/24/2023] Open
Abstract
Acinetobacter baumannii (A. baumannii) has become a notorious pathogen causing nosocomial and community-acquired infections, especially ventilator-associated pneumonia. This opportunistic pathogen is found to possess powerful genomic plasticity and numerous virulence factors that facilitate its success in the infectious process. Although the interactions between A. baumannii and the pulmonary epitheliums have been extensively studied, a complete and specific description of its overall pathogenic process is lacking. In this review, we summarize the current knowledge of the antibiotic resistance and virulence factors of A. baumannii, specifically focusing on the pathogenic mechanisms of this detrimental pathogen in respiratory infectious diseases. An expansion of the knowledge regarding A. baumannii pathogenesis will contribute to the development of effective therapies based on immunopathology or intracellular signaling pathways to eliminate this harmful pathogen during infections.
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Affiliation(s)
| | | | - Hua Zhou
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China; (Y.Y.); (Q.C.)
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Zhang D, He J, Ding X, Wang R, Chen W. GENIPOSIDE IMPROVES CLP-INDUCED SEPSIS MODEL PROGNOSIS BY UPREGULATING PPARγ TO MODULATE MONOCYTE PHENOTYPE AND CYTOKINE NETWORK. Shock 2023; 60:753-761. [PMID: 37878499 DOI: 10.1097/shk.0000000000002239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
ABSTRACT Background : We explored the efficacy and main biological mechanism of geniposide intervention in sepsis. Methods : A sepsis model was established in male BALB/c mice through cecal ligation and puncture (CLP). Different doses of geniposide (20 or 40 mg/kg) were administered intravenously at 0 and/or 24 h after CLP surgery. The survival rate of different groups was observed. In addition, the expression levels of CD16 and major histocompatibility complex class II in monocytes were assessed using flow cytometry. The concentrations of TNF-α, IL-1β, IL-6, and IL-10 in the serum were measured by ELISA. We also observed the biological effects of geniposide on CD16 and MHC-II expression levels in RAW264.7 cells, as well as the secretion of TNF-α, IL-1β, IL-6, and IL-10 in the LPS-induced RAW264.7 cell model. The PPARγ levels were determined using western blot analysis. Results : Intravenous administration of 40 mg/kg of geniposide at 0 h after CLP significantly improved the survival outcomes in the septic mouse model, with no significant benefits from low dosing (20 mg/kg) or delayed administration (24 h). The effective dose of geniposide significantly decreased the serum cytokine TNF-α, IL-1β, IL-6, and IL-10 concentrations in septic mice ( P < 0.05). Notably, in vitro assays showed that geniposide specifically increased the IL-10 level. Geniposide significantly reduced the CD16 expression ( P < 0.05) and increased MHC-II expression in monocytes ( P < 0.05). In addition, geniposide elevated the PPARγ level in monocytes ( P < 0.05). Conclusions : High-dose early-stage geniposide administration significantly improved the survival rate in a CLP mouse sepsis model by modulating the monocyte phenotype and regulating the cytokine network (IL-6/IL-10 levels). The pharmacological mechanism of geniposide action might be exerted primarily through PPARγ upregulation.
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Affiliation(s)
- Dewen Zhang
- Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jian He
- Department of Emergency and Critical Care Medicine, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xian Ding
- Department of Emergency and Critical Care Medicine, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Rui Wang
- Department of Emergency and Critical Care Medicine, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Wei Chen
- Department of Critical Care Medicine, Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Thorsted A, Pham AD, Friberg LE, Nielsen EI. Model-based assessment of neutrophil-mediated phagocytosis and digestion of bacteria across in vitro and in vivo studies. CPT Pharmacometrics Syst Pharmacol 2023; 12:1972-1987. [PMID: 37700716 PMCID: PMC10725272 DOI: 10.1002/psp4.13046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 08/30/2023] [Accepted: 09/01/2023] [Indexed: 09/14/2023] Open
Abstract
Neutrophil granulocytes are key components of the host response against pathogens, and severe neutropenia, with neutrophil counts below 0.5 × 106 cells/mL, renders patients increasingly vulnerable to infections. Published in vitro (n = 7) and in vivo (n = 5) studies with time-course information on bacterial and neutrophil counts were digitized to characterize the kinetics of neutrophil-mediated bacterial killing and inform on the immune systems' contribution to the clearance of bacterial infections. A mathematical model for the in vitro dynamics of bacteria and the kinetics of neutrophil-mediated phagocytosis and digestion was developed, which was extended to in vivo studies in immune-competent and immune-compromised mice. Neutrophil-mediated bacterial killing was described by two first-order processes-phagocytosis and digestion-scaled by neutrophil concentration, where 50% of the maximum was achieved at neutrophil counts of 1.19 × 106 cells/mL (phagocytosis) and 6.55 × 106 cells/mL (digestion). The process efficiencies diminished as the phagocytosed bacteria to total neutrophils ratio increased (with 50% reduction at a ratio of 3.41). Neutrophil in vivo dynamics were captured through the characterization of myelosuppressive drug effects and postinoculation neutrophil influx into lungs and by system differences (27% bacterial growth and 9.3% maximum capacity, compared with in vitro estimates). Predictions showed how the therapeutically induced reduction of neutrophil counts enabled bacterial growth, especially when falling below 0.5 × 106 cells/mL, whereas control individuals could deal with all tested bacterial burdens (up to 109 colony forming units/g lung). The model-based characterization of neutrophil-mediated bacterial killing simultaneously predicted data across in vitro and in vivo studies and may be used to inform the capacity of host-response at the individual level.
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Affiliation(s)
| | - Anh Duc Pham
- Present address:
Leiden Academic Centre for Drug ResearchLeiden UniversityLeidenThe Netherlands
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Di Pilato V, Willison E, Marchese A. The microbiology and pathogenesis of nonfermenting Gram-negative infections. Curr Opin Infect Dis 2023; 36:537-544. [PMID: 37732777 PMCID: PMC10624403 DOI: 10.1097/qco.0000000000000969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
PURPOSE OF REVIEW This review provides an overview of most recent evidence about pathogenesis traits and virulence factors contributing to successful colonization or infection by P. aeruginosa , A. baumannii , S. maltophilia and B. cepacia complex, among the most clinically relevant nonfermenting Gram-negative bacteria (NFGNB). RECENT FINDINGS The growing clinical importance of NFGNB as important opportunistic pathogens causing difficult-to-treat infections in a fragile patients' population in stressed by numerous studies. Identification of novel virulence factors and deciphering of their mechanisms of action have greatly furthered our understanding of NFGNB pathogenesis, revealing that each pathogen-specific armamentarium of virulence factors (adhesins, motility, capsule, biofilm, lipopolysaccharide, exotoxins, exoenzymes, secretion systems, siderophores) can be likely responsible for the difference in the pathophysiology even in the context of a similar infection site. Emerging evidence of the immunomodulatory effect of some virulence factors is also acknowledged. SUMMARY NFGNB continue to be a serious global problem as cause of life-threatening opportunistic infections, owing to a highly heterogeneous content of virulence factors and their extensive number of intrinsic resistance mechanisms. Further efforts in development of novel effective antimicrobials and of alternative strategies targeting key virulence factors are warranted.
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Affiliation(s)
- Vincenzo Di Pilato
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa
| | - Edward Willison
- Microbiology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Anna Marchese
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa
- Microbiology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
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Le J, Kulatheepan Y, Jeyaseelan S. Role of toll-like receptors and nod-like receptors in acute lung infection. Front Immunol 2023; 14:1249098. [PMID: 37662905 PMCID: PMC10469605 DOI: 10.3389/fimmu.2023.1249098] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 07/28/2023] [Indexed: 09/05/2023] Open
Abstract
The respiratory system exposed to microorganisms continuously, and the pathogenicity of these microbes not only contingent on their virulence factors, but also the host's immunity. A multifaceted innate immune mechanism exists in the respiratory tract to cope with microbial infections and to decrease tissue damage. The key cell types of the innate immune response are macrophages, neutrophils, dendritic cells, epithelial cells, and endothelial cells. Both the myeloid and structural cells of the respiratory system sense invading microorganisms through binding or activation of pathogen-associated molecular patterns (PAMPs) to pattern recognition receptors (PRRs), including Toll-like receptors (TLRs) and NOD-like receptors (NLRs). The recognition of microbes and subsequent activation of PRRs triggers a signaling cascade that leads to the activation of transcription factors, induction of cytokines/5chemokines, upregulation of cell adhesion molecules, recruitment of immune cells, and subsequent microbe clearance. Since numerous microbes resist antimicrobial agents and escape innate immune defenses, in the future, a comprehensive strategy consisting of newer vaccines and novel antimicrobials will be required to control microbial infections. This review summarizes key findings in the area of innate immune defense in response to acute microbial infections in the lung. Understanding the innate immune mechanisms is critical to design host-targeted immunotherapies to mitigate excessive inflammation while controlling microbial burden in tissues following lung infection.
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Affiliation(s)
- John Le
- Laboratory of Lung Biology, Department of Pathobiological Sciences and Center for Lung Biology and Disease, School of Veterinary Medicine, Louisiana State University (LSU) and Agricultural & Mechanical College, Baton Rouge, LA, United States
| | - Yathushigan Kulatheepan
- Laboratory of Lung Biology, Department of Pathobiological Sciences and Center for Lung Biology and Disease, School of Veterinary Medicine, Louisiana State University (LSU) and Agricultural & Mechanical College, Baton Rouge, LA, United States
| | - Samithamby Jeyaseelan
- Laboratory of Lung Biology, Department of Pathobiological Sciences and Center for Lung Biology and Disease, School of Veterinary Medicine, Louisiana State University (LSU) and Agricultural & Mechanical College, Baton Rouge, LA, United States
- Section of Pulmonary and Critical Care Department of Medicine, LSU Health Sciences Center, New Orleans, LA, United States
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8
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Hong YW, Ban GH, Bae D, Kim SA. Microbial investigation of aquacultured olive flounder (Paralichthys olivaceus) from farm to table based on high-throughput sequencing. Int J Food Microbiol 2023; 389:110111. [PMID: 36746029 DOI: 10.1016/j.ijfoodmicro.2023.110111] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 01/02/2023] [Accepted: 01/28/2023] [Indexed: 02/03/2023]
Abstract
The microbial ecologies of fish, such as the olive flounder (Paralichthys olivaceus), one of the most widely consumed fish in East Asia, remain to be elucidated. The microbiome of olive flounder and related environmental samples (i.e., feed, water, workers' aprons and gloves) were collected from six different sources (i.e., a fish farm, a transporting truck, a Wando market and restaurant, and a Seoul market and restaurant). These samples (n = 102) were investigated at various farm-to-distribution stages based on their 16S rRNA sequences. The microbial communities of fish from the farms and trucks were dominated by Photobacterium (>86 %) and showed distinct differences from fish from the Wando and Seoul markets and restaurants. There was also a significant difference in fish microbiomes according to geographical location. The relative abundances of Shewanella, Acinetobacter, Enterobacteriaceae, and Pseudomonas increased as the distribution and consumption stages of the supply chain advanced. The percentages of Shewanella (24.74 %), Acinetobacter (18.32 %), and Enterobacteriaceae (11.24 %) in Wando, and Pseudomonas (42.98 %) in Seoul markets and restaurants implied the importance of sanitation control in these areas. Alpha and beta diversity results corresponded to taxonomic analyses and showed the division of two groups (i.e., fish from the production and transporting stage (farm and truck fish) and fish from the distribution and consumption stages (market and restaurant fish)). The present study provides an in-depth understanding of olive flounder and its environmental microbiomes and suggests control measures to improve food safety.
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Affiliation(s)
- Ye Won Hong
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, South Korea
| | - Ga-Hee Ban
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, South Korea
| | - Dongryeoul Bae
- Research Institute of Pharmaceutical Science, Gyeongsang National University, Jinju, South Korea
| | - Sun Ae Kim
- Department of Food Science and Biotechnology, Ewha Womans University, Seoul, South Korea.
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Shadan A, Pathak A, Ma Y, Pathania R, Singh RP. Deciphering the virulence factors, regulation, and immune response to Acinetobacter baumannii infection. Front Cell Infect Microbiol 2023; 13:1053968. [PMID: 36968113 PMCID: PMC10038080 DOI: 10.3389/fcimb.2023.1053968] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Deciphering the virulence factors, regulation, and immune response to Acinetobacter baumannii infectionAcinetobacter baumannii is a gram-negative multidrug-resistant nosocomial pathogen and a major cause of hospital acquired infetions. Carbapenem resistant A. baumannii has been categorised as a Priority1 critial pathogen by the World Health Organisation. A. baumannii is responsible for infections in hospital settings, clinical sectors, ventilator-associated pneumonia, and bloodstream infections with a mortality rates up to 35%. With the development of advanced genome sequencing, molecular mechanisms of manipulating bacterial genomes, and animal infection studies, it has become more convenient to identify the factors that play a major role in A. baumannii infection and its persistence. In the present review, we have explored the mechanism of infection, virulence factors, and various other factors associated with the pathogenesis of this organism. Additionally, the role of the innate and adaptive immune response, and the current progress in the development of innovative strategies to combat this multidrug-resistant pathogen is also discussed.
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Affiliation(s)
- Afreen Shadan
- Department of Microbiology, Dr. Shyama Prasad Mukherjee University, Ranchi, Jharkhand, India
| | - Avik Pathak
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
| | - Ying Ma
- College of Resources and Environment, Southwest University, Chongqing, China
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
| | - Ranjana Pathania
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, India
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
| | - Rajnish Prakash Singh
- Department of Bioengineering and Biotechnology, Birla Institute of Technology, Ranchi, Jharkhand, India
- *Correspondence: Ying Ma, ; Ranjana Pathania, ; Rajnish Prakash Singh,
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Qu M, Zhu H, Zhang X. Extracellular vesicle-mediated regulation of macrophage polarization in bacterial infections. Front Microbiol 2022; 13:1039040. [PMID: 36619996 PMCID: PMC9815515 DOI: 10.3389/fmicb.2022.1039040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/25/2022] [Indexed: 12/24/2022] Open
Abstract
Extracellular vesicles (EVs) are nanoscale membrane-enveloped vesicles secreted by prokaryotic and eukaryotic cells, which are commonly defined as membrane vesicles (MVs) and exosomes, respectively. They play critical roles in the bacteria-bacteria and bacteria-host interactions. In infectious diseases caused by bacteria, as the first line of defense against pathogens, the macrophage polarization mode commonly determines the success or failure of the host's response to pathogen aggression. M1-type macrophages secrete pro-inflammatory factors that support microbicidal activity, while alternative M2-type macrophages secrete anti-inflammatory factors that perform an antimicrobial immune response but partially allow pathogens to replicate and survive intracellularly. Membrane vesicles (MVs) released from bacteria as a distinctive secretion system can carry various components, including bacterial effectors, nucleic acids, or lipids to modulate macrophage polarization in host-pathogen interaction. Similar to MVs, bacteria-infected macrophages can secrete exosomes containing a variety of components to manipulate the phenotypic polarization of "bystander" macrophages nearby or long distance to differentiate into type M1 or M2 to regulate the course of inflammation. Exosomes can also repair tissue damage associated with the infection by upregulating the levels of anti-inflammatory factors, downregulating the pro-inflammatory factors, and regulating cellular biological behaviors. The study of the mechanisms by which EVs modulate macrophage polarization has opened new frontiers in delineating the molecular machinery involved in bacterial pathogenesis and challenges in providing new strategies for diagnosis and therapy.
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Affiliation(s)
- Mingjuan Qu
- School of Life Sciences, Ludong University, Yantai, China,Yantai Key Laboratory of Animal Pathogenetic Microbiology and Immunology, Yantai, China
| | - Hongwei Zhu
- School of Life Sciences, Ludong University, Yantai, China,Yantai Key Laboratory of Animal Pathogenetic Microbiology and Immunology, Yantai, China,Shandong Provincial Key Laboratory of Quality Safety Monitoring and Risk Assessment for Animal Products, Jinan, China
| | - Xingxiao Zhang
- School of Life Sciences, Ludong University, Yantai, China,Yantai Key Laboratory of Animal Pathogenetic Microbiology and Immunology, Yantai, China,Shandong Breeding Environmental Control Engineering Laboratory, Yantai, China,*Correspondence: Xingxiao Zhang, ✉
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Li FJ, Starrs L, Mathur A, Ishii H, Man SM, Burgio G. Differential activation of NLRP3 inflammasome by Acinetobacter baumannii strains. PLoS One 2022; 17:e0277019. [PMID: 36318583 PMCID: PMC9624416 DOI: 10.1371/journal.pone.0277019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 10/17/2022] [Indexed: 11/07/2022] Open
Abstract
Acinetobacter baumannii is an emerging nosocomial, opportunistic pathogen with growing clinical significance globally. A. baumannii has an exceptional ability to rapidly develop drug resistance. It is frequently responsible for ventilator-associated pneumonia in clinical settings and inflammation resulting in severe sepsis. The inflammatory response is mediated by host pattern-recognition receptors and the inflammasomes. Inflammasome activation triggers inflammatory responses, including the secretion of the pro-inflammatory cytokines IL-1β and IL-18, the recruitment of innate immune effectors against A. baumannii infection, and the induction programmed cell death by pyroptosis. An important knowledge gap is how variation among clinical isolates affects the host’s innate response and activation of the inflammasome during A. baumannii infection. In this study, we compared nine A. baumannii strains, including clinical locally-acquired isolates, in their ability to induce activation of the inflammasome and programmed cell death in primary macrophages, epithelial lung cell line and mice. We found a variation in survival outcomes of mice and bacterial dissemination in organs among three commercially available A. baumannii strains, likely due to the differences in virulence between strains. Interestingly, we found variability among A. baumannii strains in activation of the NLRP3 inflammasome, non-canonical Caspase-11 pathway, plasmatic secretion of the pro-inflammatory cytokine IL-1β and programmed cell death. Our study highlights the importance of utilising multiple bacterial strains and clinical isolates with different virulence to investigate the innate immune response to A. baumannii infection.
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Affiliation(s)
- Fei-Ju Li
- Division of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Lora Starrs
- Division of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Anukriti Mathur
- Division of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Hikari Ishii
- Division of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Si Ming Man
- Division of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Gaetan Burgio
- Division of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
- * E-mail:
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CD14 signaling mediates lung immunopathology and mice mortality induced by Achromobacter xylosoxidans. Inflamm Res 2022; 71:1535-1546. [PMID: 36280620 PMCID: PMC9592541 DOI: 10.1007/s00011-022-01641-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 09/02/2022] [Accepted: 09/08/2022] [Indexed: 11/11/2022] Open
Abstract
Objective and design Our research aimed to investigate the role of CD14 in pulmonary infection by Achromobacter xylosoxidans in an experimental murine model. Methods C57Bl/6 or CD14-deficient mice were infected intratracheally with non-lethal inoculum of A. xylosoxidans. At times 1, 3 and 7 days after infection, lungs, bronchoalveolar lavage and blood were collected. CD14 gene expression was determined by RT-PCR. The bacterial load in the lungs was assessed by counting colony forming units (CFU). Cytokines, chemokines, lipocalin-2 and sCD14 were quantified by the ELISA method. Inflammatory infiltrate was observed on histological sections stained with HE, and leukocyte subtypes were assessed by flow cytometry. In another set of experiments, C57Bl/6 or CD14-deficient mice were inoculated with lethal inoculum and the survival rate determined. Results CD14-deficient mice are protected from A. xylosoxidans-induced death, which is unrelated to bacterial load. The lungs of CD14-deficient mice presented a smaller area of tissue damage, less neutrophil and macrophage infiltration, less pulmonary edema, and a lower concentration of IL-6, TNF-α, CXCL1, CCL2 and CCL3 when compared with lungs of C57Bl/6 mice. We also observed that A. xylosoxidans infection increases the number of leukocytes expressing mCD14 and the levels of sCD14 in BALF and serum of C57Bl/6-infected mice. Conclusions In summary, our data show that in A. xylosoxidans infection, the activation of CD14 induces intense pulmonary inflammatory response resulting in mice death. Supplementary Information The online version contains supplementary material available at 10.1007/s00011-022-01641-8.
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Behairy MY, Abdelrahman AA, Toraih EA, Ibrahim EEDA, Azab MM, Sayed AA, Hashem HR. Investigation of TLR2 and TLR4 Polymorphisms and Sepsis Susceptibility: Computational and Experimental Approaches. Int J Mol Sci 2022; 23:ijms231810982. [PMID: 36142893 PMCID: PMC9504743 DOI: 10.3390/ijms231810982] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 09/13/2022] [Indexed: 11/19/2022] Open
Abstract
Toll-like receptors (TLR) play an eminent role in the regulation of immune responses to invading pathogens during sepsis. TLR genetic variants might influence individual susceptibility to developing sepsis. The current study aimed to investigate the association of genetic polymorphisms of the TLR2 and TLR4 with the risk of developing sepsis with both a pilot study and in silico tools. Different in silico tools were used to predict the impact of our SNPs on protein structure, stability, and function. Furthermore, in our prospective study, all patients matching the inclusion criteria in the intensive care units (ICU) were included and followed up, and DNA samples were genotyped using real-time polymerase chain reaction (RT-PCR) technology. There was a significant association between TLR2 Arg753Gln polymorphisms and sepsis under the over-dominant model (p = 0.043). In contrast, we did not find a significant difference with the TLR4 Asp299Gly polymorphism with sepsis. However, there was a significant association between TLR4 Asp299Gly polymorphisms and Acinetobacter baumannii infection which is quite a virulent organism in ICU (p = 0.001) and post-surgical cohorts (p = 0.033). Our results conclude that the TLR2 genotype may be a risk factor for sepsis in adult patients.
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Affiliation(s)
- Mohammed Y. Behairy
- Department of Microbiology and Immunology, Faculty of Pharmacy, University of Sadat City, Sadat City 32958, Egypt
| | - Ali A. Abdelrahman
- Department of Microbiology and Immunology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Eman A. Toraih
- Department of Surgery, School of Medicine, Tulane University, New Orleans, LA 70112, USA
- Genetics Unit, Department of Histology & Cell Biology, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt
| | - Emad El-Deen A. Ibrahim
- Department of Anesthesia, Intensive Care and Pain Management, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt
| | - Marwa M. Azab
- Department of Microbiology and Immunology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
- Correspondence: (M.M.A.); (A.A.S.); Tel.: +20-10-2429-9630 (M.M.A.); +966-14-861-8888 (A.A.S.)
| | - Anwar A. Sayed
- Department of Medical Microbiology and Immunology, Taibah University, Madinah 42353, Saudi Arabia
- Department of Surgery and Cancer, Imperial College London, London SW7 2BX, UK
- Correspondence: (M.M.A.); (A.A.S.); Tel.: +20-10-2429-9630 (M.M.A.); +966-14-861-8888 (A.A.S.)
| | - Hany R. Hashem
- Department of Microbiology and Immunology, Faculty of Pharmacy, Fayoum University, Fayoum 63514, Egypt
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14
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Tiku V, Kew C, Kofoed EM, Peng Y, Dikic I, Tan MW. Acinetobacter baumannii Secretes a Bioactive Lipid That Triggers Inflammatory Signaling and Cell Death. Front Microbiol 2022; 13:870101. [PMID: 35615509 PMCID: PMC9125205 DOI: 10.3389/fmicb.2022.870101] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii is a highly pathogenic Gram-negative bacterium that causes severe infections with very high fatality rates. A. baumannii infection triggers innate as well as adaptive immunity, however, our understanding of the inflammatory factors secreted by A. baumannii that alarm the immune system remains limited. In this study, we report that the lab adapted and clinical strains of A. baumannii secrete an inflammatory bioactive factor which activates TLR2, leading to canonical IRAK4-dependent NF-κB signaling and production of pro-inflammatory cytokines interleukin (IL)-6 and IL-8 and activation of the inflammasome pathway causing pyroptotic cell death. Biochemical fractionation of the A. baumannii culture filtrate revealed the hydrophobic nature of the inflammatory factor. Concordantly, lipase treatment of the culture filtrate or TLR2 inhibition in macrophages abrogated NF-κB activation and cell death induction. Culture filtrates from the LPS- and lipoprotein-deficient A. baumannii mutants retain immuno-stimulatory properties suggesting that a lipid other than these known stimulatory molecules can trigger inflammation during A. baumannii infection. Our results reveal that A. baumannii secretes a previously unappreciated inflammatory bioactive lipid that activates multiple pro-inflammatory signaling pathways and induces cell death in human and murine macrophages.
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Affiliation(s)
- Varnesh Tiku
- Department of Infectious Diseases, Genentech, South San Francisco, CA, United States
- *Correspondence: Varnesh Tiku,
| | - Chun Kew
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
| | - Eric M. Kofoed
- Department of Infectious Diseases, Genentech, South San Francisco, CA, United States
| | - Yutian Peng
- Department of Infectious Diseases, Genentech, South San Francisco, CA, United States
| | - Ivan Dikic
- Faculty of Medicine, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Max Planck Institute of Biophysics, Frankfurt, Germany
- Ivan Dikic,
| | - Man-Wah Tan
- Department of Infectious Diseases, Genentech, South San Francisco, CA, United States
- Man-Wah Tan,
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15
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Tansho-Nagakawa S, Sato Y, Ubagai T, Kikuchi-Ueda T, Kamoshida GO, Nishida S, Ono Y. Histopathological Analysis of Acinetobacter baumannii Lung Infection in a Mouse Model. Pol J Microbiol 2022; 70:469-477. [PMID: 35003278 PMCID: PMC8702610 DOI: 10.33073/pjm-2021-044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/31/2021] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is the main causative pathogen of nosocomial infections that causes severe infections in the lungs. In this study, we analyzed the histopathological characteristics of lung infection with two strains of A. baumannii (ATCC 19606 and the clinical isolate TK1090) and Pseudomonas aeruginosa PAO-1 in C3H/HeN mice to evaluate the virulence of A. baumannii. Survival was evaluated over 14 days. At 1, 2, 5, or 14 days postinfection, mice of C3H/HeN were sacrificed, and histopathological analysis of lung specimens was also performed. Histopathological changes and accumulation of neutrophils and macrophages in the lungs after infection with A. baumannii and P. aeruginosa were analyzed. Following intratracheal inoculation, the lethality of ATCC 19606- and TK1090-infected mice was lower than that of PAO-1-infected mice. However, when mice were inoculated with a sub-lethal dose of A. baumannii, the lung bacterial burden remained in the mice until 14 days post-infection. Additionally, histopathological analysis revealed that macrophages infiltrated the lung foci of ATCC 19606-, TK1090-, and PAO-1-infected mice. Although neutrophils infiltrated the lung foci of ATCC 19606- and TK1090-infected mice, they poorly infiltrated the lung foci of PAO-1-infected mice. Accumulation of these cells in the lung foci of ATCC 19606- and TK1090-infected mice, but not PAO-1-infected mice, was observed for 14 days post-infection. These results suggest that A. baumannii is not completely eliminated despite the infiltration of immune cells in the lungs and that inflammation lasts for prolonged periods in the lungs. Further studies are required to understand the mechanism of A. baumannii infection, and novel drugs and vaccines should be developed to prevent A. baumannii infection.
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Affiliation(s)
- Shigeru Tansho-Nagakawa
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yoshinori Sato
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Tsuneyuki Ubagai
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Takane Kikuchi-Ueda
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - G O Kamoshida
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Satoshi Nishida
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yasuo Ono
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
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16
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Wienhold SM, Brack MC, Nouailles G, Krishnamoorthy G, Korf IHE, Seitz C, Wienecke S, Dietert K, Gurtner C, Kershaw O, Gruber AD, Ross A, Ziehr H, Rohde M, Neudecker J, Lienau J, Suttorp N, Hippenstiel S, Hocke AC, Rohde C, Witzenrath M. Preclinical Assessment of Bacteriophage Therapy against Experimental Acinetobacter baumannii Lung Infection. Viruses 2021; 14:33. [PMID: 35062236 PMCID: PMC8778864 DOI: 10.3390/v14010033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 11/16/2022] Open
Abstract
Respiratory infections caused by multidrug-resistant Acinetobacter baumannii are difficult to treat and associated with high mortality among critically ill hospitalized patients. Bacteriophages (phages) eliminate pathogens with high host specificity and efficacy. However, the lack of appropriate preclinical experimental models hampers the progress of clinical development of phages as therapeutic agents. Therefore, we tested the efficacy of a purified lytic phage, vB_AbaM_Acibel004, against multidrug-resistant A. baumannii clinical isolate RUH 2037 infection in immunocompetent mice and a human lung tissue model. Sham- and A. baumannii-infected mice received a single-dose of phage or buffer via intratracheal aerosolization. Group-specific differences in bacterial burden, immune and clinical responses were compared. Phage-treated mice not only recovered faster from infection-associated hypothermia but also had lower pulmonary bacterial burden, lower lung permeability, and cytokine release. Histopathological examination revealed less inflammation with unaffected inflammatory cellular recruitment. No phage-specific adverse events were noted. Additionally, the bactericidal effect of the purified phage on A. baumannii was confirmed after single-dose treatment in an ex vivo human lung infection model. Taken together, our data suggest that the investigated phage has significant potential to treat multidrug-resistant A. baumannii infections and further support the development of appropriate methods for preclinical evaluation of antibacterial efficacy of phages.
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Affiliation(s)
- Sandra-Maria Wienhold
- Division of Pulmonary Inflammation, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (S.-M.W.); (M.C.B.); (G.N.); (G.K.); (J.L.); (A.C.H.)
| | - Markus C. Brack
- Division of Pulmonary Inflammation, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (S.-M.W.); (M.C.B.); (G.N.); (G.K.); (J.L.); (A.C.H.)
- Department of Infectious Diseases and Respiratory Medicine, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (N.S.); (S.H.)
| | - Geraldine Nouailles
- Division of Pulmonary Inflammation, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (S.-M.W.); (M.C.B.); (G.N.); (G.K.); (J.L.); (A.C.H.)
| | - Gopinath Krishnamoorthy
- Division of Pulmonary Inflammation, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (S.-M.W.); (M.C.B.); (G.N.); (G.K.); (J.L.); (A.C.H.)
| | - Imke H. E. Korf
- Department of Microorganisms, Leibniz Institute DSMZGerman Collection of Microorganisms and Cell Cultures, 38124 Braunschweig, Germany; (I.H.E.K.); (C.R.)
- Department of Pharmaceutical Biotechnology, Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), 38124 Braunschweig, Germany; (C.S.); (S.W.); (A.R.); (H.Z.)
| | - Claudius Seitz
- Department of Pharmaceutical Biotechnology, Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), 38124 Braunschweig, Germany; (C.S.); (S.W.); (A.R.); (H.Z.)
| | - Sarah Wienecke
- Department of Pharmaceutical Biotechnology, Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), 38124 Braunschweig, Germany; (C.S.); (S.W.); (A.R.); (H.Z.)
| | - Kristina Dietert
- Department of Veterinary Pathology, Freie Universität Berlin, 14163 Berlin, Germany; (K.D.); (C.G.); (O.K.); (A.D.G.)
- Veterinary Centre for Resistance Research, Freie Universität Berlin, 14163 Berlin, Germany
| | - Corinne Gurtner
- Department of Veterinary Pathology, Freie Universität Berlin, 14163 Berlin, Germany; (K.D.); (C.G.); (O.K.); (A.D.G.)
| | - Olivia Kershaw
- Department of Veterinary Pathology, Freie Universität Berlin, 14163 Berlin, Germany; (K.D.); (C.G.); (O.K.); (A.D.G.)
| | - Achim D. Gruber
- Department of Veterinary Pathology, Freie Universität Berlin, 14163 Berlin, Germany; (K.D.); (C.G.); (O.K.); (A.D.G.)
| | - Anton Ross
- Department of Pharmaceutical Biotechnology, Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), 38124 Braunschweig, Germany; (C.S.); (S.W.); (A.R.); (H.Z.)
| | - Holger Ziehr
- Department of Pharmaceutical Biotechnology, Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), 38124 Braunschweig, Germany; (C.S.); (S.W.); (A.R.); (H.Z.)
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz-Centre for Infection Research (HZI), 38124 Braunschweig, Germany;
| | - Jens Neudecker
- Department of General, Visceral, Vascular and Thoracic Surgery, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany;
| | - Jasmin Lienau
- Division of Pulmonary Inflammation, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (S.-M.W.); (M.C.B.); (G.N.); (G.K.); (J.L.); (A.C.H.)
| | - Norbert Suttorp
- Department of Infectious Diseases and Respiratory Medicine, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (N.S.); (S.H.)
| | - Stefan Hippenstiel
- Department of Infectious Diseases and Respiratory Medicine, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (N.S.); (S.H.)
| | - Andreas C. Hocke
- Division of Pulmonary Inflammation, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (S.-M.W.); (M.C.B.); (G.N.); (G.K.); (J.L.); (A.C.H.)
- Department of Infectious Diseases and Respiratory Medicine, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (N.S.); (S.H.)
| | - Christine Rohde
- Department of Microorganisms, Leibniz Institute DSMZGerman Collection of Microorganisms and Cell Cultures, 38124 Braunschweig, Germany; (I.H.E.K.); (C.R.)
| | - Martin Witzenrath
- Division of Pulmonary Inflammation, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (S.-M.W.); (M.C.B.); (G.N.); (G.K.); (J.L.); (A.C.H.)
- Department of Infectious Diseases and Respiratory Medicine, Charité–Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10115 Berlin, Germany; (N.S.); (S.H.)
- German Center for Lung Research (DZL), Partner Site Charité, 10117 Berlin, Germany
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17
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Abstract
Acinetobacter baumannii is a highly antibiotic-resistant bacterial pathogen known to cause severe life-threatening infections, including pneumonia, meningitis, and sepsis. Recent emergence of this bacterium as a serious nosocomial pathogen has led to categorization of A. baumannii as a “high-priority” pathogen by the World Health Organization (WHO), for which research efforts are urgently required to develop therapeutic interventions. Some of the properties that make A. baumannii a serious pathogen include its capacity to tolerate high levels of stress and enhanced expression of efflux pumps that enable high degrees of antibiotic resistance. Virulence mechanisms employed by A. baumannii to establish successful infection and host responses elicited against A. baumannii to counter the infection are discussed in detail in this article.
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Affiliation(s)
- Varnesh Tiku
- Vir Biotechnology, San Francisco, California, USA
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18
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Bergamini G, Perico ME, Di Palma S, Sabatini D, Andreetta F, Defazio R, Felici A, Ferrari L. Mouse pneumonia model by Acinetobacter baumannii multidrug resistant strains: Comparison between intranasal inoculation, intratracheal instillation and oropharyngeal aspiration techniques. PLoS One 2021; 16:e0260627. [PMID: 34855837 PMCID: PMC8638993 DOI: 10.1371/journal.pone.0260627] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 11/12/2021] [Indexed: 11/18/2022] Open
Abstract
Infectious pneumonia induced by multidrug resistant (MDR) Acinetobacter baumannii strains is among the most common and deadly forms of healthcare acquired infections. Over the years, different strategies have been put in place to increase host susceptibility to MDR A. baumannii, since only a self-limiting pneumonia with no or limited local bacterial replication was frequently obtained in mouse models. Direct instillation into the trachea or intranasal inoculation of the bacterial suspension are the techniques used to induce the infection in most of the preclinical models of pneumonia developed to date. More recently, the oropharyngeal aspiration procedure has been widely described in the literature for a variety of purposes including pathogens administration. Aim of this study was to compare the oropharyngeal aspiration technique to the intranasal inoculation and intratracheal instillation in the ability of inducing a consistent lung infection with two MDR A. baumannii clinical isolates in immunocompromised mice. Moreover, pneumonia obtained by bacteria administration with two out of three techniques, intratracheal and oropharyngeal, was characterised in terms of histopathology of pulmonary lesions, biomarkers of inflammation level and leukocytes cells infiltration extent after mice treatment with either vehicle or the antibiotic tigecycline. The data generated clearly showed that both strains were not able to colonize the lungs when inoculated by intranasal route. By contrast, the bacterial load in lungs of mice intratracheally or oropharyngeally infected significantly increased during 26 hours of monitoring, thus highlighting the ability of these strains to generate the infection when directly instilled into the lower respiratory airways. Furthermore, the intragroup variability of mice was significantly reduced with respect to those intranasally administered. Tigecycline was efficacious in lung bacterial load and cytokines release reduction. Findings were supported by semi-quantitative histopathological evaluation of the pulmonary lesions and by inflammatory biomarkers analysis. To conclude, both intratracheal instillation and oropharyngeal aspiration techniques showed to be suitable methods for inducing a robust and consistent pneumonia infection in mice when difficult MDR A. baumannii clinical isolates were used. Noteworthy, oropharyngeal aspiration not requiring specific technical skills and dedicated equipment, was proven to be a safer, easier and faster technique in comparison to the intratracheal instillation.
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Affiliation(s)
- Gabriella Bergamini
- Translational Microbiology, Antibacterial Discovery, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
- * E-mail:
| | - Maria Elisa Perico
- In vitro Pharmacology, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
| | - Stefano Di Palma
- Pathology, Preclinical Development, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Daniela Sabatini
- In vitro Pharmacology, Microbiology Discovery, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Filippo Andreetta
- In vitro Pharmacology, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
| | - Rossella Defazio
- Pathology, Preclinical Development, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Antonio Felici
- In vitro Pharmacology, Microbiology Discovery, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Livia Ferrari
- Translational Microbiology, Antibacterial Discovery, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
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19
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Karmakar S, Nath S, Sarkar B, Chakraborty S, Paul S, Karan M, Pal C. Insect vectors' saliva and gut microbiota as a blessing in disguise: probability versus possibility. Future Microbiol 2021; 16:657-670. [PMID: 34100305 DOI: 10.2217/fmb-2020-0239] [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] [Indexed: 11/21/2022] Open
Abstract
Drawing of host blood is a natural phenomenon during the bite of blood-probing insect vectors. Along with the blood meal, the vectors introduce salivary components and a trail of microbiota. In the case of infected vectors, the related pathogen accompanies the aforementioned biological components. In addition to Anopheles gambiae or Anopheles stephensi, the bites of other nonmalarial vectors cannot be ignored in malaria-endemic regions. Similarly, the bite incidence of Phlebotomus papatasi cannot be ignored in visceral leishmaniasis-endemic regions. Even the chances of getting bitten by uninfected vectors are higher than the infected vectors. We have discussed the probability or possibility of uninfected, infected, and/or nonvector's saliva and gut microbiota as a therapeutic option leading to the initial deterrent to pathogen establishment.
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Affiliation(s)
- Suman Karmakar
- Cellular Immunology & Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India.,Vector Molecular Biology Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India
| | - Supriya Nath
- Cellular Immunology & Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India.,Vector Molecular Biology Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India
| | - Biswajyoti Sarkar
- Cellular Immunology & Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India.,Vector Molecular Biology Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India
| | - Sondipon Chakraborty
- Vector Molecular Biology Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India
| | - Sharmistha Paul
- Vector Molecular Biology Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India
| | - Mintu Karan
- Vector Molecular Biology Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India
| | - Chiranjib Pal
- Cellular Immunology & Experimental Therapeutics Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India.,Vector Molecular Biology Laboratory, Department of Zoology, West Bengal State University, Barasat, North 24 Parganas, West Bengal, 700126, India
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20
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Li X, Liu X, Horvatovich P, Hu Y, Zhang J. Proteomics Landscape of Host-Pathogen Interaction in Acinetobacter baumannii Infected Mouse Lung. Front Genet 2021; 12:563516. [PMID: 34025711 PMCID: PMC8138179 DOI: 10.3389/fgene.2021.563516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 04/14/2021] [Indexed: 12/15/2022] Open
Abstract
Acinetobacter baumannii is an important pathogen of nosocomial infection worldwide, which can primarily cause pneumonia, bloodstream infection, and urinary tract infection. The increasing drug resistance rate of A. baumannii and the slow development of new antibacterial drugs brought great challenges for clinical treatment. Host immunity is crucial to the defense of A. baumannii infection, and understanding the mechanisms of immune response can facilitate the development of new therapeutic strategies. To characterize the system-level changes of host proteome in immune response, we used tandem mass tag (TMT) labeling quantitative proteomics to compare the proteome changes of lungs from A. baumannii infected mice with control mice 6 h after infection. A total of 6,218 proteins were identified in which 6,172 could be quantified. With threshold p < 0.05 and relative expression fold change > 1.2 or < 0.83, we found 120 differentially expressed proteins. Bioinformatics analysis showed that differentially expressed proteins after infection were associated with receptor recognition, NADPH oxidase (NOX) activation and antimicrobial peptides. These differentially expressed proteins were involved in the pathways including leukocyte transendothelial migration, phagocyte, neutrophil degranulation, and antimicrobial peptides. In conclusion, our study showed proteome changes in mouse lung tissue due to A. baumannii infection and suggested the important roles of NOX, neutrophils, and antimicrobial peptides in host response. Our results provide a potential list of protein candidates for the further study of host-bacteria interaction in A. baumannii infection. Data are available via ProteomeXchange with identifier PXD020640.
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Affiliation(s)
- Xin Li
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaofen Liu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Peter Horvatovich
- Department of Analytical Biochemistry, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
| | - Yingwei Hu
- Department of Pathology, Johns Hopkins University, Baltimore, MD, United States
| | - Jing Zhang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
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21
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Fu YL, Harrison RE. Microbial Phagocytic Receptors and Their Potential Involvement in Cytokine Induction in Macrophages. Front Immunol 2021; 12:662063. [PMID: 33995386 PMCID: PMC8117099 DOI: 10.3389/fimmu.2021.662063] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/30/2021] [Indexed: 11/13/2022] Open
Abstract
Phagocytosis is an essential process for the uptake of large (>0.5 µm) particulate matter including microbes and dying cells. Specialized cells in the body perform phagocytosis which is enabled by cell surface receptors that recognize and bind target cells. Professional phagocytes play a prominent role in innate immunity and include macrophages, neutrophils and dendritic cells. These cells display a repertoire of phagocytic receptors that engage the target cells directly, or indirectly via opsonins, to mediate binding and internalization of the target into a phagosome. Phagosome maturation then proceeds to cause destruction and recycling of the phagosome contents. Key subsequent events include antigen presentation and cytokine production to alert and recruit cells involved in the adaptive immune response. Bridging the innate and adaptive immunity, macrophages secrete a broad selection of inflammatory mediators to orchestrate the type and magnitude of an inflammatory response. This review will focus on cytokines produced by NF-κB signaling which is activated by extracellular ligands and serves a master regulator of the inflammatory response to microbes. Macrophages secrete pro-inflammatory cytokines including TNFα, IL1β, IL6, IL8 and IL12 which together increases vascular permeability and promotes recruitment of other immune cells. The major anti-inflammatory cytokines produced by macrophages include IL10 and TGFβ which act to suppress inflammatory gene expression in macrophages and other immune cells. Typically, macrophage cytokines are synthesized, trafficked intracellularly and released in response to activation of pattern recognition receptors (PRRs) or inflammasomes. Direct evidence linking the event of phagocytosis to cytokine production in macrophages is lacking. This review will focus on cytokine output after engagement of macrophage phagocytic receptors by particulate microbial targets. Microbial receptors include the PRRs: Toll-like receptors (TLRs), scavenger receptors (SRs), C-type lectin and the opsonic receptors. Our current understanding of how macrophage receptor stimulation impacts cytokine production is largely based on work utilizing soluble ligands that are destined for endocytosis. We will instead focus this review on research examining receptor ligation during uptake of particulate microbes and how this complex internalization process may influence inflammatory cytokine production in macrophages.
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Affiliation(s)
- Yan Lin Fu
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Rene E. Harrison
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
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22
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Mea HJ, Yong PVC, Wong EH. An overview of Acinetobacter baumannii pathogenesis: Motility, adherence and biofilm formation. Microbiol Res 2021; 247:126722. [PMID: 33618061 DOI: 10.1016/j.micres.2021.126722] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/13/2022]
Abstract
The Gram-negative opportunistic pathogen Acinetobacter baumannii has gain notoriety in recent decades, primarily due to its propensity to cause nosocomial infections in critically ill patients. Its global spread, multi-drug resistance features and plethora of virulence factors make it a serious threat to public health worldwide. Though much effort has been expended in uncovering its successes, it continues to confound researchers due to its highly adaptive nature, mutating to meet the needs of a given environment. Its persistence in the clinical setting allows it to be in close proximity to a potential host, where contact can be made facilitating infection and colonization. In this article, we aim to provide a current overview of the bacterial virulence factors, specifically focusing on factors involved in the initial stages of infection, highlighting the role of adaptation facilitated by two-component systems and biofilm formation. Finally, the study of host-pathogen interactions using available animal models, their suitability, notable findings and some perspectives moving forward are also discussed.
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Affiliation(s)
- Hing Jian Mea
- School of Biosciences, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Phelim Voon Chen Yong
- School of Biosciences, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Eng Hwa Wong
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University Lakeside Campus, 47500, Subang Jaya, Selangor Darul Ehsan, Malaysia.
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Yan Q, Hao S, Shi F, Zou Y, Song X, Li L, Li Y, Guo H, He R, Zhao L, Ye G, Tang H. Epigallocatechin-3-gallate reduces liver and immune system damage in Acinetobacter baumannii-loaded mice with restraint stress. Int Immunopharmacol 2021; 92:107346. [PMID: 33412390 DOI: 10.1016/j.intimp.2020.107346] [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: 09/12/2020] [Revised: 12/08/2020] [Accepted: 12/25/2020] [Indexed: 11/28/2022]
Abstract
AIM Due to the significant increase in the antimicrobial resistance of Acinetobacter baumannii (A. baumannii), new drugs to block the progression of infection are strongly needed. Epigallocatechin-3-gallate (EGCG), a major component of green tea, has exhibited potential activity against A. baumannii in vitro. The aim of this study was to determine if EGCG could be used for pretreating stress-related effects, liver damage, and immune dysfunction caused by A. baumannii infection in vivo. METHODS Levels of stress hormones, oxidative stress, liver damage, and immune components were analyzed in a murine infection model in which the mice were pretreated with EGCG for one week then intranasally inoculated with A. baumannii. The mice were restrained for 12 h to promote infection because A. baumannii is an opportunistic pathogen. The pretreatment efficacy of EGCG against A. baumannii in mice was assessed for 24 h after the bacterial infection. RESULTS Restraint stress strengthened the damage from the A. baumannii infection. Pretreatment with EGCG in the murine pneumonia model markedly reduced stress hormones, oxidative metabolites, and proinflammatory cytokine production. EGCG also increased the immune function by increasing the levels of sIgA, T cells and neutrophils after infection. Moreover, pretreatment with EGCG significantly decreased the liver damage by inhibiting the levels of transaminases, oxidative stress metabolites, and cytokines, while maintaining the normal activity of CYP450 enzymes in the liver. CONCLUSION EGCG was efficacious as a preventative treatment for the damage seen in an experimental model of A. baumannii infection.
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Affiliation(s)
- Qiaohua Yan
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Suqi Hao
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Fei Shi
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuanfeng Zou
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Xu Song
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Lixia Li
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Yinglun Li
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Hongrui Guo
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Ran He
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Ling Zhao
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Gang Ye
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Huaqiao Tang
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
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Multidrug-resistant Acinetobacter baumannii as an emerging concern in hospitals. Mol Biol Rep 2021; 48:6987-6998. [PMID: 34460060 PMCID: PMC8403534 DOI: 10.1007/s11033-021-06690-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/24/2021] [Indexed: 02/07/2023]
Abstract
Acinetobacter baumannii has become a major concern for scientific attention due to extensive antimicrobial resistance. This resistance causes an increase in mortality rate because strains resistant to antimicrobial agents are a major challenge for physicians and healthcare workers regarding the eradication of either hospital or community-based infections. These strains with emerging resistance are a serious issue for patients in the intensive care unit (ICU). Antibiotic resistance has increased because of the acquirement of mobile genetic elements such as transposons, plasmids, and integrons and causes the prevalence of multidrug resistance strains (MDR). In addition, an increase in carbapenem resistance, which is used as last line antibiotic treatment to eliminate infections with multidrug-resistant Gram-negative bacteria, is a major concern. Carbapenems resistant A. baumannii (CR-Ab) is a worldwide problem. Because these strains are often resistant to all other commonly used antibiotics. Therefore, pathogenic multi-drug resistance A. baumannii (MDR-Ab) associated infections become hard to eradicate. Plasmid-mediated resistance causes outbreaks of extensive drug-resistant. A. baumannii (XDR-Ab). In addition, recent outbreaks relating to livestock and community settings illustrate the existence of large MDR-Ab strain reservoirs within and outside hospital settings. The purpose of this review, proper monitoring, prevention, and treatment are required to control (XDR-Ab) infections. Attachment, the formation of biofilms and the secretion of toxins, and low activation of inflammatory responses are mechanisms used by pathogenic A. baumannii strain. This review will discuss some aspects associated with antibiotics resistance in A. baumannii as well as cover briefly phage therapy as an alternative therapeutic treatment.
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25
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Lázaro-Díez M, Chapartegui-González I, Suberbiola B, Ocejo-Vinyals JG, López-Hoyos M, Ramos-Vivas J. Gene expression profiling in human neutrophils after infection with Acinetobacter baumannii in vitro. PLoS One 2020; 15:e0242674. [PMID: 33253325 PMCID: PMC7703911 DOI: 10.1371/journal.pone.0242674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 11/08/2020] [Indexed: 12/24/2022] Open
Abstract
Acinetobacter baumannii is a Gram negative nosocomial pathogen that has acquired increasing worldwide notoriety due to its high antibiotic resistance range and mortality rates in hospitalized patients. Therefore, it is necessary to better understand key aspects of A. baumannii pathogenesis such as host-pathogen interactions. In this report, we analyzed both gene expression and cytokine production by human neutrophils infected with A. baumannii. Our assays reveal a proinflammatory response of neutrophils after A. baumannii infection, since intracellular transcription of effector proteins such as COX-2, transcription factors, and proinflammatory cytokines resulted significantly upregulated in neutrophils infected by A. baumannii, compared with unstimulated human neutrophils. Translation and release of CXCL-8, IL-1β and TNF-α by neutrophils was confirmed by protein quantification in culture supernatants. Results obtained in this report reinforce the importance of human neutrophils in controlling A. baumannii infections but also emphasize the proinflammatory nature of these host-pathogen interactions as a target for future immunomodulatory therapies.
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Affiliation(s)
- María Lázaro-Díez
- Health Research Institute Marqués de Valdecilla (IDIVAL), Santander, Spain
- Division of Infectious Diseases, Department of Pediatrics, UCSD, San Diego, California, United States of America
| | - Itziar Chapartegui-González
- Health Research Institute Marqués de Valdecilla (IDIVAL), Santander, Spain
- Department of Microbiology and Immunology, UTMB, Galveston, Texas, United States of America
| | - Borja Suberbiola
- Health Research Institute Marqués de Valdecilla (IDIVAL), Santander, Spain
- Intensive Care Department, University Hospital Marqués de Valdecilla, Santander, Spain
| | | | - Marcos López-Hoyos
- Health Research Institute Marqués de Valdecilla (IDIVAL), Santander, Spain
- Immunology Department, University Hospital Marqués de Valdecilla, Santander, Spain
| | - José Ramos-Vivas
- Health Research Institute Marqués de Valdecilla (IDIVAL), Santander, Spain
- Spanish Network for Research in Infectious Diseases (REIPI), ISCIII, Madrid, Spain
- * E-mail:
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Sato Y, Tansho-Nagakawa S, Ubagai T, Ono Y. Analysis of Immune Responses in Acinetobacter baumannii-Infected Klotho Knockout Mice: A Mouse Model of Acinetobacter baumannii Infection in Aged Hosts. Front Immunol 2020; 11:601614. [PMID: 33329595 PMCID: PMC7719750 DOI: 10.3389/fimmu.2020.601614] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/27/2020] [Indexed: 12/24/2022] Open
Abstract
Acinetobacter baumannii is an important opportunistic pathogen that primarily afflicts elderly people. To clarify the pathogenicity of A. baumannii in the elderly, we investigated immune responses to A. baumannii ATCC 19606 infection in klotho knockout (KO) mice, the mouse model of aging. Following intravenous inoculation, the mice seldom displayed severe symptoms. However, the survival rate was 56% at 7 days post-infection. Bacteria were detected in the lungs of klotho KO mice but not klotho wildtype (WT) mice at 7 days post-infection. Neutrophils, eosinophils, interstitial macrophages, and monocyte/dendritic cell subset in the lungs of klotho KO mice were transiently induced after infection with A. baumannii. The number of alveolar macrophages in klotho KO mice was lower than that in klotho WT mice, except for 1 day post-infection. CD11b expression on neutrophils and alveolar macrophages in the lungs of klotho KO mice was seldom upregulated by the infection. These results suggested that immune functions eliminating bacteria in the lungs of klotho KO mice were insufficient. CD11blow conventional DC cells hardly increased in klotho KO mice infected with A. baumannii. Additionally, the production of interleukin (IL)-10 in the sera of klotho KO mice was significantly higher than that in klotho WT mice, whereas that production of interferon-gamma was not detected in the sera of klotho KO mice. These results suggested that acquired immune responses were hardly induced in klotho KO mice. IL-1β, CXCL1, CXCL2, and CCL2 expression was significantly higher in the lungs of klotho KO mice infected with A. baumannii than in those of klotho WT mice at 1 day post-infection. These results suggested that pulmonary inflammation was elicited in klotho KO mice during early infection. The expression levels of proinflammatory cytokines significantly correlated with TLR9 expression in the lungs of klotho KO mice. The collective results demonstrate an A. baumannii infection state in aged hosts and suggest that pulmonary inflammation and bacterial burden should be noted in aged hosts even in the absence of severe symptoms of A. baumannii infection.
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Affiliation(s)
- Yoshinori Sato
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Shigeru Tansho-Nagakawa
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Tsuneyuki Ubagai
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yasuo Ono
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
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Deng Q, Zhang J, Zhang M, Liu Z, Zhong Y, Liu S, Cui R, Shi Y, Zeng H, Yang X, Lin C, Luo Y, Chen H, Wu W, Wu J, Zhang T, Lu Y, Liu X, Zou Q, Huang W. Rapid Identification of KL49 Acinetobacter baumannii Associated with Clinical Mortality. Infect Drug Resist 2020; 13:4125-4132. [PMID: 33209042 PMCID: PMC7669520 DOI: 10.2147/idr.s278891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/21/2020] [Indexed: 01/01/2023] Open
Abstract
Objective We aimed to establish a tool for rapid identification of KL49 Acinetobacter baumannii. Methods Based on the capsular polysaccharide (CPS) synthesis genes database, we investigated the distribution of K locus type 49 (KL49) genes in other KL types and established a rapid identification method for KL49. We collected 61 clinical carbapenem-resistant A. baumannii (CRAB) strains, identified KL49 by gtr100 detection, and used whole genome sequencing (WGS) for verification. A mouse pneumonia model was used to confirm the hypervirulence phenotype. We tested the presence of gtr100 gene in 165 CRAB strains from three provinces in China and evaluated the correlation of gtr100 carrying CRAB infection with mortality. Results The gtr100 gene is the CPS synthesis gene found only in KL49. We screened out nine WGS-validated KL49 strains from 61 CRAB clinical strains using polymerase chain reaction (PCR) to detect the gtr100 gene. The survival rates of KL49 strains were significantly lower than nonKL49 strains in a mouse pneumonia model. The survival rates of LAC-4 gtr100 knockout strain decreased significantly. Analysis of phylogenetics showed the worldwide spread of KL49 A. baumannii. Infection of gtr100 carrying CRAB is an independent risk for mortality (OR, 10.76; 95%CI: 3.08–37.55; p<0.001). Conclusion The hypervirulence phenotype of KL49 CRAB and the association with mortality highlight the urgent need for implementing control measures. The rapid identification assay has the potential to facilitate early medical intervention and worldwide surveillance.
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Affiliation(s)
- Qiuyang Deng
- Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Jinyong Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Min Zhang
- Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Zhou Liu
- Second Affiliated Hospital of Anhui Medical University, Hefei, People's Republic of China
| | - Yuxin Zhong
- Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Shiyi Liu
- Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Ruiqin Cui
- Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Yun Shi
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Hao Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Xiyao Yang
- Second Affiliated Hospital of Anhui Medical University, Hefei, People's Republic of China
| | - Chuchu Lin
- Department of Nosocomial Infection Control, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Yutian Luo
- Intensive Care Unit, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Huaisheng Chen
- Intensive Care Unit, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Weiyuan Wu
- Department of Clinical Microbiology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Jinsong Wu
- Department of Clinical Microbiology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Tianle Zhang
- Guangdong Medical University, Dongguan, People's Republic of China
| | - Yuemei Lu
- Department of Clinical Microbiology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Xueyan Liu
- Intensive Care Unit, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
| | - Quanming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Wei Huang
- Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen Institute of Respiratory Diseases, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology, Shenzhen, Guangdong 518020, People's Republic of China
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Innate Immune Effectors Play Essential Roles in Acute Respiratory Infection Caused by Klebsiella pneumoniae. J Immunol Res 2020; 2020:5291714. [PMID: 33163539 PMCID: PMC7607282 DOI: 10.1155/2020/5291714] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/16/2020] [Accepted: 10/12/2020] [Indexed: 12/24/2022] Open
Abstract
Innate immune effectors constitute the first line of host defense against pathogens. However, the roles of these effectors are not clearly defined during Klebsiella pneumoniae (K. pneumoniae) respiratory infection. In the current study, we established an acute pneumonia model of K. pneumoniae respiratory infection in mice and confirmed that the injury was most severe 48 h post infection. Flow cytometric assay demonstrated that alveolar macrophages were the predominant cells in BALF before infection, and neutrophils were quickly recruited after infection, and this was in consistent with the kinetics of chemokine expression. Further, we depleted neutrophils, macrophages, and complement pathways in vivo and challenged these mice with a sublethal dose of K. pneumonia, the result showed that 80%, 60%, and 40% of mice were died in these groups, respectively, while no deaths occurred in the control group. Besides, innate immune effector depleted mice showed higher bacterial burdens in lungs and blood, companied with more severe lung damage and increased levels of cytokine/chemokine expression. These results demonstrated that the innate immune effectors are critical in the early controlling of K. pneumoniae infection, and neutrophils are the most important. Thus, alternative strategies targeting these innate immune effectors may be effective in controlling of K. pneumoniae respiratory infection.
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Carvalheira A, Silva J, Teixeira P. Acinetobacter spp. in food and drinking water - A review. Food Microbiol 2020; 95:103675. [PMID: 33397609 DOI: 10.1016/j.fm.2020.103675] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 01/01/2023]
Abstract
Acinetobacter spp. has emerged as a pathogen of major public health concern due to their increased resistance to antibiotics and their association with a wide range of nosocomial infections, community-acquired infections and war and natural disaster-related infections. It is recognized as a ubiquitous organism however, information about the prevalence of different pathogenic species of this genus in food sources and drinking water is scarce. Since the implementation of molecular techniques, the role of foods as a source of several species, including the Acinetobacter baumannii group, has been elucidated. Multidrug resistance was also detected among Acinetobacter spp. isolated from food products. This highlights the importance of foods as potential sources of dissemination of Acinetobacter spp. between the community and clinical environments and reinforces the need for further investigations on the potential health risks of Acinetobacter spp. as foodborne pathogens. The aim of this review was to summarize the published data on the occurrence of Acinetobacter spp. in different food sources and drinking water. This information should be taken into consideration by those responsible for infection control in hospitals and other healthcare facilities.
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Affiliation(s)
- Ana Carvalheira
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal
| | - Joana Silva
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal
| | - Paula Teixeira
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005, Porto, Portugal.
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30
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Alarcón-Vila C, Baroja-Mazo A, de Torre-Minguela C, Martínez CM, Martínez-García JJ, Martínez-Banaclocha H, García-Palenciano C, Pelegrin P. CD14 release induced by P2X7 receptor restricts inflammation and increases survival during sepsis. eLife 2020; 9:60849. [PMID: 33135636 PMCID: PMC7690950 DOI: 10.7554/elife.60849] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/31/2020] [Indexed: 12/12/2022] Open
Abstract
P2X7 receptor activation induces the release of different cellular proteins, such as CD14, a glycosylphosphatidylinositol (GPI)-anchored protein to the plasma membrane important for LPS signaling via TLR4. Circulating CD14 has been found at elevated levels in sepsis, but the exact mechanism of CD14 release in sepsis has not been established. Here, we show for first time that P2X7 receptor induces the release of CD14 in extracellular vesicles, resulting in a net reduction in macrophage plasma membrane CD14 that functionally affects LPS, but not monophosphoryl lipid A, pro-inflammatory cytokine production. Also, we found that during a murine model of sepsis, P2X7 receptor activity is important for maintaining elevated levels of CD14 in biological fluids and a decrease in its activity results in higher bacterial load and exacerbated organ damage, ultimately leading to premature deaths. Our data reveal that P2X7 is a key receptor for helping to clear sepsis because it maintains elevated concentrations of circulating CD14 during infection. When the immune system detects an infection, it often launches an inflammatory response to fight off the disease. This defense mechanism is activated by a cascade of signaling molecules that can aggravate inflammation, causing it to damage the body’s own tissues and organs. This life-threatening reaction is referred to as sepsis, and kills around 11 million people each year. New approaches are therefore needed to help alleviate the damage caused by this condition. The inflammatory response is often triggered by proteins called receptors, which sit on the surface of immune cells. When these receptors are activated, they induce cells to secrete proteins that travel around the body and activate immune cells that can eliminate the infection. In 2016, a group of researchers showed that a receptor called P2X7 stimulates the release of a signaling molecule called CD14. Patients with sepsis often have elevated amounts of CD14 in their bloodstream. Yet, it remained unclear what causes this rise in CD14 and what role this molecule plays in the development of sepsis. Now, Alarcón-Vila et al. – including some of the researchers involved in the 2016 study – have investigated the role of P2X7 in mice undergoing sepsis. This was done by puncturing the mice’s intestines, causing bacteria to leak out and initiate an over-active immune response. Alarcón-Vila et al. found that mice lacking the P2X7 receptor had less CD14 and struggled to eliminate the bacterial infection from their system. This increase in bacteria caused excessive damage to the mice’s organs, ultimately leading to premature death. These findings suggest that P2X7 plays an important role in preventing the onset of sepsis by helping maintain high levels of CD14 following infection. This result could help to identify new therapies that reduce the mortality rates of septic infections.
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Affiliation(s)
- Cristina Alarcón-Vila
- Línea de Inflamación Molecular, Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Alberto Baroja-Mazo
- Línea de Inflamación Molecular, Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Carlos de Torre-Minguela
- Línea de Inflamación Molecular, Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Carlos M Martínez
- Plataforma de Patología, Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Murcia, Spain
| | - Juan J Martínez-García
- Línea de Inflamación Molecular, Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Helios Martínez-Banaclocha
- Línea de Inflamación Molecular, Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
| | | | - Pablo Pelegrin
- Línea de Inflamación Molecular, Instituto Murciano de Investigación Biosanitaria IMIB-Arrixaca, Hospital Clínico Universitario Virgen de la Arrixaca, Murcia, Spain
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Chen W. Host Innate Immune Responses to Acinetobacter baumannii Infection. Front Cell Infect Microbiol 2020; 10:486. [PMID: 33042864 PMCID: PMC7521131 DOI: 10.3389/fcimb.2020.00486] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 08/05/2020] [Indexed: 12/23/2022] Open
Abstract
Acinetobacter baumannii has emerged as a major threat to global public health and is one of the key human pathogens in healthcare (nosocomial and community-acquired)-associated infections. Moreover, A. baumannii rapidly develops resistance to multiple antibiotics and is now globally regarded as a serious multidrug resistant pathogen. There is an urgent need to develop novel vaccines and immunotherapeutics as alternatives to antibiotics for clinical management of A. baumannii infection. However, our knowledge of host immune responses to A. baumannii infection and the identification of novel therapeutic targets are significantly lacking. This review highlights the recent advances and critical gaps in our understanding how A. baumannii interacts with the host innate pattern-recognition receptors, induces a cascade of inflammatory cytokine and chemokine responses, and recruits innate immune effectors (such as neutrophils and macrophages) to the site of infection for effective control of the infection. Such knowledge will facilitate the identification of new targets for the design and development of effective therapeutics and vaccines to fight this emerging threat.
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Affiliation(s)
- Wangxue Chen
- Human Health and Therapeutics (HHT) Research Center, National Research Council Canada, Ottawa, ON, Canada.,Department of Biology, Brock University, St. Catharines, ON, Canada
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Palmer LD, Minor KE, Mettlach JA, Rivera ES, Boyd KL, Caprioli RM, Spraggins JM, Dalebroux ZD, Skaar EP. Modulating Isoprenoid Biosynthesis Increases Lipooligosaccharides and Restores Acinetobacter baumannii Resistance to Host and Antibiotic Stress. Cell Rep 2020; 32:108129. [PMID: 32905776 PMCID: PMC7519801 DOI: 10.1016/j.celrep.2020.108129] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 06/19/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023] Open
Abstract
Acinetobacter baumannii is a leading cause of ventilator-associated pneumonia and a critical threat due to multidrug resistance. The A. baumannii outer membrane is an asymmetric lipid bilayer composed of inner leaflet glycerophospholipids and outer leaflet lipooligosaccharides. Deleting mlaF of the maintenance of lipid asymmetry (Mla) system causes A. baumannii to become more susceptible to pulmonary surfactants and antibiotics and decreases bacterial survival in the lungs of mice. Spontaneous suppressor mutants isolated from infected mice contain an ISAba11 insertion upstream of the ispB initiation codon, an essential isoprenoid biosynthesis gene. The insertion restores antimicrobial resistance and virulence to ΔmlaF. The suppressor strain increases lipooligosaccharides, suggesting that the mechanism involves balancing the glycerophospholipids/lipooligosaccharides ratio on the bacterial surface. An identical insertion exists in an extensively drug-resistant A. baumannii isolate, demonstrating its clinical relevance. These data show that the stresses bacteria encounter during infection select for genomic rearrangements that increase resistance to antimicrobials.
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Affiliation(s)
- Lauren D Palmer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Keaton E Minor
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Joshua A Mettlach
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Emilio S Rivera
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA; Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Kelli L Boyd
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Richard M Caprioli
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA; Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Jeffrey M Spraggins
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA; Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
| | - Zachary D Dalebroux
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA.
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33
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Wolff NS, Jacobs MC, Haak BW, Roelofs JJTH, de Vos AF, Hugenholtz F, Wiersinga WJ. Vendor effects on murine gut microbiota and its influence on lipopolysaccharide-induced lung inflammation and Gram-negative pneumonia. Intensive Care Med Exp 2020; 8:47. [PMID: 32840685 PMCID: PMC7447702 DOI: 10.1186/s40635-020-00336-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 08/04/2020] [Indexed: 01/08/2023] Open
Abstract
Background The microbiome has emerged as an important player in the pathophysiology of a whole spectrum of diseases that affect the critically ill. We hypothesized that differences in microbiota composition across vendors can influence murine models of pulmonary lipopolysaccharide (LPS) inflammation and Gram-negative pneumonia. Methods A multi-vendor approach was used with genetically similar mice derived from three different vendors (Janvier, Envigo, Charles River). This model was employed to study the effect on the host response to a pulmonary LPS challenge (1 μg Klebsiella pneumoniae LPS, intranasal), as well as experimental K. pneumoniae infection (ATCC43816, 1 × 104 CFU, intranasal). Results Gut microbiota analysis revealed profound intervendor differences in bacterial composition as shown by beta diversity and at various taxonomic levels. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 release in lung and bronchoalveolar lavage fluid (BALF) were determined 6 and 24 h after intranasal treatment with LPS. No differences were found between the groups, with the exception for Envigo, showing a higher level of TNFα in lung and BALF at 6 h compared to Janvier and Charles River. In another set of experiments, mice from different vendors were subjected to a clinically relevant model of Gram-negative pneumonia (K. pneumoniae). At 12 and 36 h post-infection, no intervendor differences were found in bacterial dissemination, or TNFα and IL-6 levels in the lungs. In line, markers for organ failure did not differ between groups. Conclusions Although there was a marked variation in the gut microbiota composition of mice from different vendors, the hypothesized impact on our models of pulmonary inflammation and severe pneumonia was limited. This is of significance for experimental settings, showing that differences in gut microbiota do not have to lead to differences in outcome.
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Affiliation(s)
- Nora S Wolff
- Center for Experimental and Molecular Medicine, Amsterdam Infection & Immunity Institute, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands
| | - Max C Jacobs
- Center for Experimental and Molecular Medicine, Amsterdam Infection & Immunity Institute, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands
| | - Bastiaan W Haak
- Center for Experimental and Molecular Medicine, Amsterdam Infection & Immunity Institute, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands
| | - Joris J T H Roelofs
- Department of Pathology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands
| | - Alex F de Vos
- Center for Experimental and Molecular Medicine, Amsterdam Infection & Immunity Institute, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands
| | - Floor Hugenholtz
- Center for Experimental and Molecular Medicine, Amsterdam Infection & Immunity Institute, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands
| | - W Joost Wiersinga
- Center for Experimental and Molecular Medicine, Amsterdam Infection & Immunity Institute, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands. .,Department of Medicine, Division of Infectious Diseases, Amsterdam UMC, location AMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands.
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34
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Shi J, Sun T, Cui Y, Wang C, Wang F, Zhou Y, Miao H, Shan Y, Zhang Y. Multidrug resistant and extensively drug resistant Acinetobacter baumannii hospital infection associated with high mortality: a retrospective study in the pediatric intensive care unit. BMC Infect Dis 2020; 20:597. [PMID: 32787942 PMCID: PMC7422664 DOI: 10.1186/s12879-020-05321-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 08/03/2020] [Indexed: 02/06/2023] Open
Abstract
Background Multidrug resistant (MDR) and extensively drug resistant (XDR) Acinetobacter baumannii presents challenges for clinical treatment and causes high mortality in children. We aimed to assess the risk factors and overall mortality for MDR/XDR Acinetobacter baumannii infected pediatric patients. Methods This retrospective study included 102 pediatric patients who developed MDR/XDR Acinetobacter baumannii infection in the pediatric intensive care unit (PICU) of Shanghai Children’s Hospital in China from December 2014 to May 2018. Acinetobacter baumannii clinical isolates were recovered from different specimens including blood, sputum, bronchoalveolar lavage fluid, cerebrospinal fluid, ascites, hydrothorax, and urine. Antibiotic susceptibility test was determined according to the Clinical and Laboratory Standards Institute interpretive criteria. Clinical and biological data were obtained from the patients’ medical records. Results 102 patients with Acinetobacter baumannii infection were enrolled. The median age was 36 (9.6, 98.8) months, and there were 63 male in the case group. The overall mortality rate was 29.4%, while the Acinetobacter baumannii-associated mortality rate was 16.7% (17/102, 12 bloodstream infections, 4 meningitis and 1 intra-abdominal infection). Bloodstream infections occurred in 28 patients (27.5%), and 10 patients (9.8%) among them had central line-associated bloodstream infections (6 central venous catheters, 2 PICCs, 1 venous infusion port and 1 arterial catheter). Cerebrospinal fluid (CSF) cultures were positive in 4(3.9%) patients. 14(13.7%) patients got positive cultures in ascites and hydrothorax. Lower respiratory isolates (56/102) accounted for 54.9% of all patients. Non-survival patients appeared to have a lower NK cell activity (6.2% ± 3.61% vs. 9.15% ± 6.21%, P = 0.029), higher CD4+ T cell ratio (39.67% ± 12.18% vs. 32.66% ± 11.44%, P = 0.039),and a higher serum level of interlukin-8 (IL-8, 15.25 (1.62, 47.22)pg/mL vs. 0.1 (0.1, 22.99)pg/mL, P = 0.01) when Acinetobacter baumannii infection developed. Multivariate logistic analysis indicated that high serum level of Cr (RR, 0.934, 95%CI, 0.890–0.981; P = 0.007) and high BUN/ALB level (RR, 107.893, 95%CI, 1.425–870.574; p = 0.005) were associated with high risk of mortality in MDR/XDR Acinetobacter baumannii infected patients. Conclusion MDR/XDR Acinetobacter baumannii infection is a serious concern in pediatric patients with high mortality. Bloodstream and central nervous system infection accounted for high risk of death. Acute kidney injury is associated with high risk of mortality.
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Affiliation(s)
- Jingyi Shi
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Ting Sun
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Yun Cui
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Chunxia Wang
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China.,Institute of Pediatric Critical Care, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Fei Wang
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Yiping Zhou
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Huijie Miao
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Yijun Shan
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China
| | - Yucai Zhang
- Department of Critical Care Medicine, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, 20062, China. .,Institute of Pediatric Critical Care, Shanghai Jiao Tong University, Shanghai, 20062, China. .,Department of Critical Care Medicine, Shanghai, Children's Hospital, Shanghai Jiao Tong University, No.355 Luding Road, Putuo District, Shanghai, 200062, China.
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35
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Immunomodulation by Acinetobacter baumannii of endotracheal tube biofilm in ventilator-associated pneumonia. Meta Gene 2020. [DOI: 10.1016/j.mgene.2020.100672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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36
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Kim SI, Kang N, Leem S, Yang J, Jo H, Lee M, Kim HS, Dhanasekaran DN, Kim YK, Park T, Song YS. Metagenomic Analysis of Serum Microbe-Derived Extracellular Vesicles and Diagnostic Models to Differentiate Ovarian Cancer and Benign Ovarian Tumor. Cancers (Basel) 2020; 12:cancers12051309. [PMID: 32455705 PMCID: PMC7281409 DOI: 10.3390/cancers12051309] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 12/22/2022] Open
Abstract
We aimed to develop a diagnostic model identifying ovarian cancer (OC) from benign ovarian tumors using metagenomic data from serum microbe-derived extracellular vesicles (EVs). We obtained serum samples from 166 patients with pathologically confirmed OC and 76 patients with benign ovarian tumors. For model construction and validation, samples were randomly divided into training and test sets in the ratio 2:1. Isolation of microbial EVs from serum samples of the patients and 16S rDNA amplicon sequencing were carried out. Metagenomic and clinicopathologic data-based OC diagnostic models were constructed in the training set and then validated in the test set. There were significant differences in the metagenomic profiles between the OC and benign ovarian tumor groups; specifically, genus Acinetobacter was significantly more abundant in the OC group. More importantly, Acinetobacter was the only common genus identified by seven different statistical analysis methods. Among the various metagenomic and clinicopathologic data-based OC diagnostic models, the model consisting of age, serum CA-125 levels, and relative abundance of Acinetobacter showed the best diagnostic performance with the area under the receiver operating characteristic curve of 0.898 and 0.846 in the training and test sets, respectively. Thus, our findings establish a metagenomic analysis of serum microbe-derived EVs as a potential tool for the diagnosis of OC.
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Affiliation(s)
- Se Ik Kim
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul 03080, Korea; (S.I.K.); (M.L.); (H.S.K.)
| | - Nayeon Kang
- Department of Statistics, Seoul National University, Seoul 08826, Korea;
| | - Sangseob Leem
- Department of Core Technology, R&D Center, LG Household & Healthcare, Seoul 07795, Korea;
| | - Jinho Yang
- MD Healthcare Inc., Seoul 03923, Korea; (J.Y.); (Y.-K.K.)
| | - HyunA Jo
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea;
| | - Maria Lee
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul 03080, Korea; (S.I.K.); (M.L.); (H.S.K.)
| | - Hee Seung Kim
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul 03080, Korea; (S.I.K.); (M.L.); (H.S.K.)
| | - Danny N. Dhanasekaran
- Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;
| | - Yoon-Keun Kim
- MD Healthcare Inc., Seoul 03923, Korea; (J.Y.); (Y.-K.K.)
| | - Taesung Park
- Department of Statistics, Seoul National University, Seoul 08826, Korea;
- Correspondence: (T.P.); (Y.S.S.); Tel.: +82-2-880-8924 (T.P.); +82-2-2072-2822 (Y.S.S.)
| | - Yong Sang Song
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul 03080, Korea; (S.I.K.); (M.L.); (H.S.K.)
- Cancer Research Institute, Seoul National University College of Medicine, Seoul 03080, Korea;
- Correspondence: (T.P.); (Y.S.S.); Tel.: +82-2-880-8924 (T.P.); +82-2-2072-2822 (Y.S.S.)
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37
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Vázquez-López R, Solano-Gálvez SG, Juárez Vignon-Whaley JJ, Abello Vaamonde JA, Padró Alonzo LA, Rivera Reséndiz A, Muleiro Álvarez M, Vega López EN, Franyuti-Kelly G, Álvarez-Hernández DA, Moncaleano Guzmán V, Juárez Bañuelos JE, Marcos Felix J, González Barrios JA, Barrientos Fortes T. Acinetobacter baumannii Resistance: A Real Challenge for Clinicians. Antibiotics (Basel) 2020; 9:antibiotics9040205. [PMID: 32340386 PMCID: PMC7235888 DOI: 10.3390/antibiotics9040205] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 01/29/2020] [Accepted: 02/05/2020] [Indexed: 12/21/2022] Open
Abstract
Acinetobacter baumannii (named in honor of the American bacteriologists Paul and Linda Baumann) is a Gram-negative, multidrug-resistant (MDR) pathogen that causes nosocomial infections, especially in intensive care units (ICUs) and immunocompromised patients with central venous catheters. A. baumannii has developed a broad spectrum of antimicrobial resistance, associated with a higher mortality rate among infected patients compared with other non-baumannii species. In terms of clinical impact, resistant strains are associated with increases in both in-hospital length of stay and mortality. A. baumannii can cause a variety of infections; most involve the respiratory tract, especially ventilator-associated pneumonia, but bacteremia and skin wound infections have also been reported, the latter of which has been prominently observed in the context of war-related trauma. Cases of meningitis associated with A. baumannii have been documented. The most common risk factor for the acquisition of MDR A baumannii is previous antibiotic use, following by mechanical ventilation, length of ICU/hospital stay, severity of illness, and use of medical devices. Current efforts focus on addressing all the antimicrobial resistance mechanisms described in A. baumannii, with the objective of identifying the most promising therapeutic scheme. Bacteriophage- and artilysin-based therapeutic approaches have been described as effective, but further research into their clinical use is required.
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Affiliation(s)
- Rosalino Vázquez-López
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
- Correspondence: or ; Tel.: +52-56-270210 (ext. 7302)
| | - Sandra Georgina Solano-Gálvez
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de Mexico 04510, Mexico;
| | - Juan José Juárez Vignon-Whaley
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Jorge Andrés Abello Vaamonde
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Luis Andrés Padró Alonzo
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Andrés Rivera Reséndiz
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Mauricio Muleiro Álvarez
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Eunice Nabil Vega López
- Medical IMPACT, Infectious Diseases Department, Mexico City 53900, Mexico; (E.N.V.L.); (G.F.-K.)
| | - Giorgio Franyuti-Kelly
- Medical IMPACT, Infectious Diseases Department, Mexico City 53900, Mexico; (E.N.V.L.); (G.F.-K.)
| | - Diego Abelardo Álvarez-Hernández
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Valentina Moncaleano Guzmán
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Jorge Ernesto Juárez Bañuelos
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - José Marcos Felix
- Coordinación Ciclos Clínicos Medicina, FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico;
| | - Juan Antonio González Barrios
- Laboratorio de Medicina Genómica, Hospital Regional “1º de Octubre”, ISSSTE, Av. Instituto Politécnico Nacional 1669, Lindavista, Gustavo A. Madero, Ciudad de Mexico 07300, Mexico;
| | - Tomás Barrientos Fortes
- Dirección Sistema Universitario de Salud de la Universidad Anáhuac México (SUSA), Huixquilucan 52786, Mexico;
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Zeng X, Gu H, Peng L, Yang Y, Wang N, Shi Y, Zou Q. Transcriptome Profiling of Lung Innate Immune Responses Potentially Associated With the Pathogenesis of Acinetobacter baumannii Acute Lethal Pneumonia. Front Immunol 2020; 11:708. [PMID: 32391015 PMCID: PMC7188829 DOI: 10.3389/fimmu.2020.00708] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/30/2020] [Indexed: 02/05/2023] Open
Abstract
Acinetobacter baumannii is one of the dominating causes of nosocomial pneumonia, however, very little is known about the host immune response associated with pathogenesis of A. baumannii infection. Here, we used a hypervirulent A. baumannii to establish an acute lethal pneumonia, supported by high bacterial burdens, severe inflammatory cells infiltration and lung damage. The lung transcriptome changes in response to A. baumannii lethal pneumonia were detected by RNA sequencing. The results showed that 6,288 host genes changed expression, with 3,313 upregulated genes and 2,975 downregulated genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that genes related to TNF, cytokine-cytokine receptor interaction, Toll-like receptor, NOD-like receptor, NF-κB, Jak-STAT, HIF-1 signaling pathways, apoptosis, and phagosome were significantly upregulated. Whereas, genes associated with PI3K-AKT signaling pathway, glycolysis/gluconeogenesis, amino acid and fatty acid metabolism were downregulated. Immune cell typing highlighted the inflammatory response of innate immune cells headed by neutrophils. The reliability of RNA sequencing results were verified with selected differentially expressed genes by real-time PCR. This work provides an insight into the pathogenesis of lethal A. baumannii lung infection.
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Affiliation(s)
- Xi Zeng
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center of Immunological Products, College of Pharmacy, Army Medical University, Chongqing, China
| | - Hao Gu
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center of Immunological Products, College of Pharmacy, Army Medical University, Chongqing, China.,Institute of Biopharmaceutical Research, West China Hospital, Sichuan University, Chengdu, China.,Department of Clinical Laboratory, 971st Hospital of People's Liberation Army, Qingdao, China
| | - Liusheng Peng
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center of Immunological Products, College of Pharmacy, Army Medical University, Chongqing, China
| | - Yao Yang
- Institute of Materia Medica, College of Pharmacy, Army Medical University, Chongqing, China
| | - Ning Wang
- Institute of Biopharmaceutical Research, West China Hospital, Sichuan University, Chengdu, China
| | - Yun Shi
- Institute of Biopharmaceutical Research, West China Hospital, Sichuan University, Chengdu, China
| | - Quanming Zou
- Department of Microbiology and Biochemical Pharmacy, National Engineering Research Center of Immunological Products, College of Pharmacy, Army Medical University, Chongqing, China
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Hood-Pishchany MI, Pham L, Wijers CD, Burns WJ, Boyd KL, Palmer LD, Skaar EP, Noto MJ. Broad-spectrum suppression of bacterial pneumonia by aminoglycoside-propagated Acinetobacter baumannii. PLoS Pathog 2020; 16:e1008374. [PMID: 32168364 PMCID: PMC7094866 DOI: 10.1371/journal.ppat.1008374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 03/25/2020] [Accepted: 01/31/2020] [Indexed: 12/29/2022] Open
Abstract
Antimicrobial resistance is increasing in pathogenic bacteria. Yet, the effect of antibiotic exposure on resistant bacteria has been underexplored and may affect pathogenesis. Here we describe the discovery that propagation of the human pathogen Acinetobacter baumannii in an aminoglycoside antibiotic results in alterations to the bacterium that interact with lung innate immunity resulting in enhanced bacterial clearance. Co-inoculation of mice with A. baumannii grown in the presence and absence of the aminoglycoside, kanamycin, induces enhanced clearance of a non-kanamycin-propagated strain. This finding can be replicated when kanamycin-propagated A. baumannii is killed prior to co-inoculation of mice, indicating the enhanced bacterial clearance results from interactions with innate host defenses in the lung. Infection with kanamycin-propagated A. baumannii alters the kinetics of phagocyte recruitment to the lung and reduces pro- and anti-inflammatory cytokine and chemokine production in the lung and blood. This culminates in reduced histopathologic evidence of lung injury during infection despite enhanced bacterial clearance. Further, the antibacterial response induced by killed aminoglycoside-propagated A. baumannii enhances the clearance of multiple clinically relevant Gram-negative pathogens from the lungs of infected mice. Together, these findings exemplify cooperation between antibiotics and the host immune system that affords protection against multiple antibiotic-resistant bacterial pathogens. Further, these findings highlight the potential for the development of a broad-spectrum therapeutic that exploits a similar mechanism to that described here and acts as an innate immunity modulator. Preserving the ability to treat infectious diseases with antibiotics in the face of the rapid proliferation of drug-resistant bacterial pathogens is among the greatest challenges facing medicine. Efforts to combat antimicrobial resistance may include strategies to maximize the utility of existing antibiotics while also identifying new therapeutic targets to treat bacterial infections. Acinetobacter baumannii is a human pathogen and strains of A. baumannii have acquired multi- and pan-antibiotic resistance. Here, we demonstrate that A. baumannii that is resistant to the aminoglycoside class of antibiotics is rapidly cleared from the lungs of mice when exposed to aminoglycoside antibiotics. Exposure to aminoglycosides induces changes in A. baumannii that interact with mouse antibacterial defenses, leading to rapid clearance of the infection. Further, killed aminoglycoside-exposed A. baumannii interacts with innate immunity in the lung to enhance the clearance of other pathogenic bacteria. These findings indicate that pneumonia caused by aminoglycoside-resistant A. baumannii may be effectively treated with aminoglycoside antibiotics and also suggests that the host immune response can be targeted to enhance the clearance of bacterial infections.
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Affiliation(s)
- M. Indriati Hood-Pishchany
- Department of Pediatrics, Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Ly Pham
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Christiaan D. Wijers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - William J. Burns
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Kelli L. Boyd
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Lauren D. Palmer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Tennessee Valley Healthcare System, US Department of Veterans Affairs, Nashville, Tennessee, United States of America
- * E-mail: (EPS); (MJN)
| | - Michael J. Noto
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail: (EPS); (MJN)
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40
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Ayoub Moubareck C, Hammoudi Halat D. Insights into Acinetobacter baumannii: A Review of Microbiological, Virulence, and Resistance Traits in a Threatening Nosocomial Pathogen. Antibiotics (Basel) 2020; 9:antibiotics9030119. [PMID: 32178356 PMCID: PMC7148516 DOI: 10.3390/antibiotics9030119] [Citation(s) in RCA: 186] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/12/2022] Open
Abstract
Being a multidrug-resistant and an invasive pathogen, Acinetobacter baumannii is one of the major causes of nosocomial infections in the current healthcare system. It has been recognized as an agent of pneumonia, septicemia, meningitis, urinary tract and wound infections, and is associated with high mortality. Pathogenesis in A. baumannii infections is an outcome of multiple virulence factors, including porins, capsules, and cell wall lipopolysaccharide, enzymes, biofilm production, motility, and iron-acquisition systems, among others. Such virulence factors help the organism to resist stressful environmental conditions and enable development of severe infections. Parallel to increased prevalence of infections caused by A. baumannii, challenging and diverse resistance mechanisms in this pathogen are well recognized, with major classes of antibiotics becoming minimally effective. Through a wide array of antibiotic-hydrolyzing enzymes, efflux pump changes, impermeability, and antibiotic target mutations, A. baumannii models a unique ability to maintain a multidrug-resistant phenotype, further complicating treatment. Understanding mechanisms behind diseases, virulence, and resistance acquisition are central to infectious disease knowledge about A. baumannii. The aims of this review are to highlight infections and disease-producing factors in A. baumannii and to touch base on mechanisms of resistance to various antibiotic classes.
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Affiliation(s)
- Carole Ayoub Moubareck
- College of Natural and Health Sciences, Zayed University, Dubai P.O. Box 144534, UAE
- Correspondence: ; Tel.: +971-4-402-1745
| | - Dalal Hammoudi Halat
- Department of Pharmaceutical Sciences, School of Pharmacy, Lebanese International University, Beirut, Bekaa Campuses 1103, Lebanon;
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41
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Potential Mechanisms of Mucin-Enhanced Acinetobacter baumannii Virulence in the Mouse Model of Intraperitoneal Infection. Infect Immun 2019; 87:IAI.00591-19. [PMID: 31405959 DOI: 10.1128/iai.00591-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/07/2019] [Indexed: 12/21/2022] Open
Abstract
Porcine mucin has been commonly used to enhance the infectivity of bacterial pathogens, including Acinetobacter baumannii, in animal models, but the mechanisms for enhancement by mucin remain relatively unknown. In this study, using the mouse model of intraperitoneal (i.p.) mucin-enhanced A. baumannii infection, we characterized the kinetics of bacterial replication and dissemination and the host innate immune responses, as well as their potential contribution to mucin-enhanced bacterial virulence. We found that mucin, either admixed with or separately injected with the challenge bacterial inoculum, was able to enhance the tissue and blood burdens of A. baumannii strains of different virulence. Intraperitoneal injection of A. baumannii-mucin or mucin alone induced a significant but comparable reduction of peritoneal macrophages and lymphocytes, accompanied by a significant neutrophil recruitment and early interleukin-10 (IL-10) responses, suggesting that the resulting inflammatory cellular and cytokine responses were largely induced by the mucin. Depletion of peritoneal macrophages or neutralization of endogenous IL-10 activities showed no effect on the mucin-enhanced infectivity. However, pretreatment of mucin with iron chelator DIBI, but not deferoxamine, partially abolished its virulence enhancement ability, and replacement of mucin with iron significantly enhanced the bacterial burdens in the peritoneal cavity and lung. Taken together, our results favor the hypothesis that iron at least partially contributes to the mucin-enhanced infectivity of A. baumannii in this model.
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42
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Geisinger E, Huo W, Hernandez-Bird J, Isberg RR. Acinetobacter baumannii: Envelope Determinants That Control Drug Resistance, Virulence, and Surface Variability. Annu Rev Microbiol 2019; 73:481-506. [DOI: 10.1146/annurev-micro-020518-115714] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acinetobacter baumannii has emerged as an important nosocomial pathogen, particularly for patients in intensive care units and with invasive indwelling devices. The most recent clinical isolates are resistant to several classes of clinically important antibiotics, greatly restricting the ability to effectively treat critically ill patients. The bacterial envelope is an important driver of A. baumannii disease, both at the level of battling against antibiotic therapy and at the level of protecting from host innate immune function. This review provides a comprehensive overview of key features of the envelope that interface with both the host and antimicrobial therapies. Carbohydrate structures that contribute to protecting from the host are detailed, and mutations that alter these structures, resulting in increased antimicrobial resistance, are explored. In addition, protein complexes involved in both intermicrobial and host-microbe interactions are described. Finally we discuss regulatory mechanisms that control the nature of the cell envelope and its impact on host innate immune function.
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Affiliation(s)
- Edward Geisinger
- Department of Biology, Northeastern University, Boston, Massachusetts 02115, USA
| | - Wenwen Huo
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Juan Hernandez-Bird
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Ralph R. Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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43
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Toll-Like Receptors 2 and 4 Modulate Pulmonary Inflammation and Host Factors Mediated by Outer Membrane Vesicles Derived from Acinetobacter baumannii. Infect Immun 2019; 87:IAI.00243-19. [PMID: 31262980 DOI: 10.1128/iai.00243-19] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/11/2019] [Indexed: 11/20/2022] Open
Abstract
Pneumonia due to Gram-negative bacteria is associated with high mortality. Acinetobacter baumannii is a Gram-negative bacterium that is associated with hospital-acquired and ventilator-associated pneumonia. Bacteria have been described to release outer membrane vesicles (OMVs) that are capable of mediating systemic inflammation. The mechanism by which A. baumannii OMVs mediate inflammation is not fully defined. We sought to investigate the roles that Toll-like receptors (TLRs) play in A. baumannii OMV-mediated pulmonary inflammation. We isolated OMVs from A. baumannii cultures and intranasally introduced the OMVs into mice. Intranasal introduction of A. baumannii OMVs mediated pulmonary inflammation, which is associated with neutrophil recruitment and weight loss. In addition, A. baumannii OMVs increased the release of several chemokines and cytokines in the mouse lungs. The proinflammatory responses were partially inhibited in TLR2- and TLR4-deficient mice compared to those of wild-type mice. This study highlights the important roles of TLRs in A. baumannii OMV-induced pulmonary inflammation in vivo.
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44
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Morris FC, Dexter C, Kostoulias X, Uddin MI, Peleg AY. The Mechanisms of Disease Caused by Acinetobacter baumannii. Front Microbiol 2019; 10:1601. [PMID: 31379771 PMCID: PMC6650576 DOI: 10.3389/fmicb.2019.01601] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 06/26/2019] [Indexed: 01/29/2023] Open
Abstract
Acinetobacter baumannii is a Gram negative opportunistic pathogen that has demonstrated a significant insurgence in the prevalence of infections over recent decades. With only a limited number of “traditional” virulence factors, the mechanisms underlying the success of this pathogen remain of great interest. Major advances have been made in the tools, reagents, and models to study A. baumannii pathogenesis, and this has resulted in a substantial increase in knowledge. This article provides a comprehensive review of the bacterial virulence factors, the host immune responses, and animal models applicable for the study of this important human pathogen. Collating the most recent evidence characterizing bacterial virulence factors, their cellular targets and genetic regulation, we have encompassed numerous aspects important to the success of this pathogen, including membrane proteins and cell surface adaptations promoting immune evasion, mechanisms for nutrient acquisition and community interactions. The role of innate and adaptive immune responses is reviewed and areas of paucity in our understanding are highlighted. Finally, with the vast expansion of available animal models over recent years, we have evaluated those suitable for use in the study of Acinetobacter disease, discussing their advantages and limitations.
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Affiliation(s)
- Faye C Morris
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Carina Dexter
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Xenia Kostoulias
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Muhammad Ikhtear Uddin
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Anton Y Peleg
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, VIC, Australia
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45
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Bengoechea JA, Sa Pessoa J. Klebsiella pneumoniae infection biology: living to counteract host defences. FEMS Microbiol Rev 2019; 43:123-144. [PMID: 30452654 PMCID: PMC6435446 DOI: 10.1093/femsre/fuy043] [Citation(s) in RCA: 272] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/16/2018] [Indexed: 12/26/2022] Open
Abstract
Klebsiella species cause a wide range of diseases including pneumonia, urinary tract infections (UTIs), bloodstream infections and sepsis. These infections are particularly a problem among neonates, elderly and immunocompromised individuals. Klebsiella is also responsible for a significant number of community-acquired infections. A defining feature of these infections is their morbidity and mortality, and the Klebsiella strains associated with them are considered hypervirulent. The increasing isolation of multidrug-resistant strains has significantly narrowed, or in some settings completely removed, the therapeutic options for the treatment of Klebsiella infections. Not surprisingly, this pathogen has then been singled out as an 'urgent threat to human health' by several organisations. This review summarises the tremendous progress that has been made to uncover the sophisticated immune evasion strategies of K. pneumoniae. The co-evolution of Klebsiella in response to the challenge of an activated immune has made Klebsiella a formidable pathogen exploiting stealth strategies and actively suppressing innate immune defences to overcome host responses to survive in the tissues. A better understanding of Klebsiella immune evasion strategies in the context of the host-pathogen interactions is pivotal to develop new therapeutics, which can be based on antagonising the anti-immune strategies of this pathogen.
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Affiliation(s)
- José A Bengoechea
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Joana Sa Pessoa
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast BT9 7BL, UK
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46
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Pires S, Parker D. Innate Immune Responses to Acinetobacter baumannii in the Airway. J Interferon Cytokine Res 2019; 39:441-449. [PMID: 31013462 DOI: 10.1089/jir.2019.0008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Acinetobacter baumannii is an emerging opportunistic pathogen that has risen to become a serious global threat, prevalent in health care settings and the community, which results in high morbidity and mortality rates. Its alarming expansion of antibiotic resistance is one of the most problematic traits of A. baumannii and as so, this bacterium has been classified as a serious threat and high priority target by the CDC. The most common types of infections induced by this pathogen include pneumonia (both hospital and community acquired), bacteremia, skin and soft tissue, urinary tract infections, endocarditis, and meningitis. Nosocomial pneumonia is the most prevalent of these. This review summarizes the current state of the signaling and innate immune components activated in response to A. baumannii infection in the airway.
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Affiliation(s)
- Sílvia Pires
- Department of Pathology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Dane Parker
- Department of Pathology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey
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47
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2-Hydroxylation of Acinetobacter baumannii Lipid A Contributes to Virulence. Infect Immun 2019; 87:IAI.00066-19. [PMID: 30745327 PMCID: PMC6434125 DOI: 10.1128/iai.00066-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 12/15/2022] Open
Abstract
Acinetobacter baumannii causes a wide range of nosocomial infections. This pathogen is considered a threat to human health due to the increasingly frequent isolation of multidrug-resistant strains. Acinetobacter baumannii causes a wide range of nosocomial infections. This pathogen is considered a threat to human health due to the increasingly frequent isolation of multidrug-resistant strains. There is a major gap in knowledge on the infection biology of A. baumannii, and only a few virulence factors have been characterized, including lipopolysaccharide. The lipid A expressed by A. baumannii is hepta-acylated and contains 2-hydroxylaurate. The late acyltransferases controlling the acylation of lipid A have been already characterized. Here, we report the characterization of A. baumannii LpxO, which encodes the enzyme responsible for the 2-hydroxylation of lipid A. By genetic methods and mass spectrometry, we demonstrate that LpxO catalyzes the 2-hydroxylation of the laurate transferred by A. baumannii LpxL. LpxO-dependent lipid A 2-hydroxylation protects A. baumannii from polymyxin B, colistin, and human β-defensin 3. LpxO contributes to the survival of A. baumannii in human whole blood and is required for pathogen survival in the waxmoth Galleria mellonella. LpxO also protects Acinetobacter from G. mellonella antimicrobial peptides and limits their expression. Further demonstrating the importance of LpxO-dependent modification in immune evasion, 2-hydroxylation of lipid A limits the activation of the mitogen-activated protein kinase Jun N-terminal protein kinase to attenuate inflammatory responses. In addition, LpxO-controlled lipid A modification mediates the production of the anti-inflammatory cytokine interleukin-10 (IL-10) via the activation of the transcriptional factor CREB. IL-10 in turn limits the production of inflammatory cytokines following A. baumannii infection. Altogether, our studies suggest that LpxO is a candidate for the development of anti-A. baumannii drugs.
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48
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Li FJ, Starrs L, Burgio G. Tug of war between Acinetobacter baumannii and host immune responses. Pathog Dis 2019; 76:5290314. [PMID: 30657912 DOI: 10.1093/femspd/ftz004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023] Open
Abstract
Acinetobacter baumannii is an emerging nosocomial, opportunistic pathogen with growing clinical significance. Acinetobacter baumannii has an exceptional ability to rapidly develop drug resistance and to adhere to abiotic surfaces, including medical equipment, significantly promoting bacterial spread and also limiting our ability to control A. baumannii infections. Consequently, A. baumannii is frequently responsible for ventilator-associated pneumonia in clinical settings. In order to develop an effective treatment strategy, understanding host-pathogen interactions during A. baumannii infection is crucial. Various A. baumannii virulence factors have been identified as targets of host innate pattern-recognition receptors, which leads to activation of downstream inflammasomes to develop inflammatory responses, and the recruitment of innate immune effectors against A. baumannii infection. To counteract host immune attack, A. baumannii regulates its expression of different virulence factors. This review summarizes the significance of mechanisms of host-bacteria interaction, as well as different bacteria and host defense mechanisms during A. baumannii infection.
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Affiliation(s)
- Fei-Ju Li
- Department of Immunology and infectious Diseases, John Curtin School of Medical Research, Australian National University, 131 Garran Road, Acton, ACT 2601, Australia
| | - Lora Starrs
- Department of Immunology and infectious Diseases, John Curtin School of Medical Research, Australian National University, 131 Garran Road, Acton, ACT 2601, Australia
| | - Gaetan Burgio
- Department of Immunology and infectious Diseases, John Curtin School of Medical Research, Australian National University, 131 Garran Road, Acton, ACT 2601, Australia
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49
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Palmer LD, Green ER, Sheldon JR, Skaar EP. Assessing Acinetobacter baumannii Virulence and Persistence in a Murine Model of Lung Infection. Methods Mol Biol 2019; 1946:289-305. [PMID: 30798564 DOI: 10.1007/978-1-4939-9118-1_26] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Acinetobacter baumannii is a Gram-negative opportunistic pathogen and a leading cause of ventilator-associated pneumonia. Murine models of A. baumannii lung infection allow researchers to experimentally assess A. baumannii virulence and host response. Intranasal administration of A. baumannii models acute lung infection. This chapter describes the methods to test A. baumannii virulence in a murine model of lung infection, including assessing the competitive index of a bacterial mutant and the associated inflammatory responses.
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Affiliation(s)
- Lauren D Palmer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Erin R Green
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jessica R Sheldon
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA. .,Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
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50
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Peng C, Han J, Ye X, Zhang X. IL-33 Treatment Attenuates the Systemic Inflammation Reaction in Acinetobacter baumannii Pneumonia by Suppressing TLR4/NF-κB Signaling. Inflammation 2018; 41:870-877. [PMID: 29508184 DOI: 10.1007/s10753-018-0741-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Interleukin (IL)-33 treatment has been reported to reduce mortality in a rat model of sepsis, and the present study aimed to determine whether this effect of IL-33 is achieved through a reduction in the systemic inflammatory response in Acinetobacter baumannii pneumonia. After induction of pneumonia, rats were treated with normal saline or IL-33, and mortality over 5 days was recorded. Inflammation within lung tissues was evaluated by hematoxylin and eosin staining as well as measurement of the concentrations of IL-8 and tumor necrosis factor alpha (TNF-α) in the bronchoalveolar lavage fluid (BALF) and plasma by enzyme-linked immunosorbent assay. In addition, the expression of Toll-like receptor 4 (TLR4), ST2, and nuclear factor kappa B (NF-κB) in rat lung tissues was assessed by western blotting. The result showed that the mortality rate and systemic inflammation were significantly increased in rats upon infection with A. baumannii, as evidenced by significant increases in the IL-8 and TNF-α levels in BALF and plasma as well as increased NF-κB activity and TLR4 expression in rat lung tissues. Importantly, IL-33 (1 μg/kg) treatment significantly decreased mortality and pulmonary inflammation in A. baumannii-infected rats. Moreover, IL-33 treatment suppressed the elevation of IL-8 and TNF-α levels and inhibited TLR4 expression and NF-κB activation. Overall, these results suggest that IL-33 may decrease the mortality and inhibit the systematic inflammatory response associated with A. baumannii pneumonia by suppressing TLR4/NF-κB signaling.
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Affiliation(s)
- Chunhong Peng
- Department of Respiratory Medicine, Guizhou Provincial People's Hospital, 83 Zhongshan Road, Nanming District, Guiyang, 550002, China.
| | - Jin Han
- Department of Respiratory Medicine, Guizhou Provincial People's Hospital, 83 Zhongshan Road, Nanming District, Guiyang, 550002, China
| | - Xianwei Ye
- Department of Respiratory Medicine, Guizhou Provincial People's Hospital, 83 Zhongshan Road, Nanming District, Guiyang, 550002, China
| | - Xiangyan Zhang
- Department of Respiratory Medicine, Guizhou Provincial People's Hospital, 83 Zhongshan Road, Nanming District, Guiyang, 550002, China
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