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Davis KP, Morales Y, Ende RJ, Peters R, McCabe AL, Mecsas J, Aldridge BB. Critical role of growth medium for detecting drug interactions in Gram-negative bacteria that model in vivo responses. mBio 2024; 15:e0015924. [PMID: 38364199 PMCID: PMC10936441 DOI: 10.1128/mbio.00159-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 01/22/2024] [Indexed: 02/18/2024] Open
Abstract
The rise in infections caused by multidrug-resistant (MDR) bacteria has necessitated a variety of clinical approaches, including the use of antibiotic combinations. Here, we tested the hypothesis that drug-drug interactions vary in different media, and determined which in vitro models best predict drug interactions in the lungs. We systematically studied pair-wise antibiotic interactions in three different media, CAMHB, (a rich lab medium standard for antibiotic susceptibility testing), a urine mimetic medium (UMM), and a minimal medium of M9 salts supplemented with glucose and iron (M9Glu) with three Gram-negative ESKAPE pathogens, Acinetobacter baumannii (Ab), Klebsiella pneumoniae (Kp), and Pseudomonas aeruginosa (Pa). There were pronounced differences in responses to antibiotic combinations between the three bacterial species grown in the same medium. However, within species, PaO1 responded to drug combinations similarly when grown in all three different media, whereas Ab17978 and other Ab clinical isolates responded similarly when grown in CAMHB and M9Glu medium. By contrast, drug interactions in Kp43816, and other Kp clinical isolates poorly correlated across different media. To assess whether any of these media were predictive of antibiotic interactions against Kp in the lungs of mice, we tested three antibiotic combination pairs. In vitro measurements in M9Glu, but not rich medium or UMM, predicted in vivo outcomes. This work demonstrates that antibiotic interactions are highly variable across three Gram-negative pathogens and highlights the importance of growth medium by showing a superior correlation between in vitro interactions in a minimal growth medium and in vivo outcomes. IMPORTANCE Drug-resistant bacterial infections are a growing concern and have only continued to increase during the SARS-CoV-2 pandemic. Though not routinely used for Gram-negative bacteria, drug combinations are sometimes used for serious infections and may become more widely used as the prevalence of extremely drug-resistant organisms increases. To date, reliable methods are not available for identifying beneficial drug combinations for a particular infection. Our study shows variability across strains in how drug interactions are impacted by growth conditions. It also demonstrates that testing drug combinations in tissue-relevant growth conditions for some strains better models what happens during infection and may better inform combination therapy selection.
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Affiliation(s)
- Kathleen P. Davis
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, & Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance Boston, Boston, Massachusetts, USA
| | - Yoelkys Morales
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, & Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance Boston, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Rachel J. Ende
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, & Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance Boston, Boston, Massachusetts, USA
| | - Ryan Peters
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, & Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance Boston, Boston, Massachusetts, USA
| | - Anne L. McCabe
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, & Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance Boston, Boston, Massachusetts, USA
- Department of Basic and Clinical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York, USA
| | - Joan Mecsas
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, & Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance Boston, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Bree B. Aldridge
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, & Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance Boston, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Department of Biomedical Engineering, Tufts University School of Engineering, Medford, Massachusetts, USA
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Yang J, Wu P, Weng Y, Lin Y, Chen Z, Yu F, Lv X, Ni L, Han J. Rational Design and Antimicrobial Potency Assessment of Abaecin Analogues. ACS Biomater Sci Eng 2023; 9:6698-6714. [PMID: 37988627 DOI: 10.1021/acsbiomaterials.3c01234] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
The widespread and escalating emergence of multidrug resistance is now recognized as one of the most severe global threats to human health. To address the urgent issue of drug-resistant bacteria and the limitation of effective clinical treatments, antimicrobial peptides (AMPs) have been developed as promising substituents of conventional antibiotics. In this study, rational design strategies were employed to acquire seven cationic and α-helical engineered peptides based on the original template of Abaecin. After investigation, we found that AC7 (LLRRWKKLFKKIIRWPRPLPNPGH) demonstrated potent and broad-spectrum antimicrobial activity. Additionally, it demonstrated low cytotoxicity and hemolysis while maintaining good stability. Notably, AC7 displays the antibacterial mechanism with superior abilities in cell membrane disruption and potential DNA binding in vitro, as well as effectively disrupting biofilms. Moreover, the murine skin wound model infected with drug-resistant Pseudomonas aeruginosa was employed to evaluate the anti-infective efficacy and therapeutic potential of AC7. It was observed that AC7 displays a remarkable capacity to inhibit wound colonization, reduce levels of inflammatory cytokines (TNF-α) and inflammatory cells (white blood cells (WBC), monocytes (MONO), lymphocytes (LYMPH), neutrophils (GRAN)), promote the levels of IL-10 and VEGF, and enhance wound healing. Overall, these findings demonstrate the potential of AC7 as a viable alternative to traditional antibiotics.
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Affiliation(s)
- Jie Yang
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Peifen Wu
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Yanlin Weng
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Yayi Lin
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Zhiying Chen
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Fengfan Yu
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
| | - Xucong Lv
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
- Food Nutrition and Health Research Center, School of Advanced Manufacturing, Fuzhou University, Jinjiang, Fujian 362200, China
| | - Li Ni
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
- Food Nutrition and Health Research Center, School of Advanced Manufacturing, Fuzhou University, Jinjiang, Fujian 362200, China
| | - Jinzhi Han
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China
- Food Nutrition and Health Research Center, School of Advanced Manufacturing, Fuzhou University, Jinjiang, Fujian 362200, China
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Wu P, Yang J, Chen C, Li R, Chen S, Weng Y, Lin Y, Chen Z, Yu F, Lü X, Ni L, Han J. Rational design of Abhisin-like peptides enables generation of potent antimicrobial activity against pathogens. Appl Microbiol Biotechnol 2023; 107:6621-6640. [PMID: 37672069 DOI: 10.1007/s00253-023-12748-1] [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: 05/04/2023] [Revised: 07/01/2023] [Accepted: 08/21/2023] [Indexed: 09/07/2023]
Abstract
Infections caused by pathogens can be a significant challenge in wound healing, particularly when antimicrobial resistance is a factor. This can pose a serious threat to human health and well-being. In this scenario, it is imperative to explore novel antimicrobial agents to fight against multi-drug resistant (MDR) pathogenic bacteria. This study employed rational design strategies, including truncation, amino acid replacement, and heterozygosity, to obtain seven α-helical, cationic, and engineered peptides based on the original template of Abhisin. Among the analogs of Abhisin, AB7 displayed broad-spectrum and potent antimicrobial activity, superior targeting of membranes and DNA, and the ability to disrupt biofilms and anti-endotoxins in vitro. Additionally, we evaluated the anti-infection ability of AB7 using a murine skin wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) and found that AB7 displayed negligible toxicity both in vitro and in vivo. Furthermore, AB7 exhibited desirable therapeutic efficacy by reducing bacterial burden and pro-inflammatory mediators, modulating cytokines, promoting wound healing, and enhancing angiogenesis. These results highlight the potential of AB7 as a promising candidate for a new antibiotic. KEY POINTS: • A α-helical, cationic, and engineered peptide AB7 was obtained based on Abhisin. • AB7 exhibited potent antimicrobial activity and multiple bactericidal actions. • AB7 effectively treated infected skin wounds in mice.
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Affiliation(s)
- Peifen Wu
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Jie Yang
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Chi Chen
- College of Modern Agricultural Engineering, Fujian Vocational College of Agriculture, Fuzhou, 350303, China
| | - Ruili Li
- College of Food Science and Technology, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shunxian Chen
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Yanlin Weng
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Yayi Lin
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Zhiying Chen
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Fengfan Yu
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Xucong Lü
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Li Ni
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China
| | - Jinzhi Han
- Institute of Food Science and Technology, College of Biological Science and Engineering, Fuzhou University, Fuzhou, 350108, China.
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Alsaab FM, Dean SN, Bobde S, Ascoli GG, van Hoek ML. Computationally Designed AMPs with Antibacterial and Antibiofilm Activity against MDR Acinetobacter baumannii. Antibiotics (Basel) 2023; 12:1396. [PMID: 37760693 PMCID: PMC10525135 DOI: 10.3390/antibiotics12091396] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023] Open
Abstract
The discovery of new antimicrobials is necessary to combat multidrug-resistant (MDR) bacteria, especially those that infect wounds and form prodigious biofilms, such as Acinetobacter baumannii. Antimicrobial peptides (AMPs) are a promising class of new therapeutics against drug-resistant bacteria, including gram-negatives. Here, we utilized a computational AMP design strategy combining database filtering technology plus positional analysis to design a series of novel peptides, named HRZN, designed to be active against A. baumannii. All of the HRZN peptides we synthesized exhibited antimicrobial activity against three MDR A. baumannii strains with HRZN-15 being the most active (MIC 4 µg/mL). This peptide also inhibited and eradicated biofilm of A. baumannii strain AB5075 at 8 and 16 µg/mL, which is highly effective. HRZN-15 permeabilized and depolarized the membrane of AB5075 rapidly, as demonstrated by the killing kinetics. HRZN 13 and 14 peptides had little to no hemolysis activity against human red blood cells, whereas HRZN-15, -16, and -17 peptides demonstrated more significant hemolytic activity. HRZN-15 also demonstrated toxicity to waxworms. Further modification of HRZN-15 could result in a new peptide with an improved toxicity profile. Overall, we successfully designed a set of new AMPs that demonstrated activity against MDR A. baumannii using a computational approach.
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Affiliation(s)
- Fahad M. Alsaab
- School of Systems Biology, George Mason University, Manassas, VA 20110, USA (S.B.)
- College of Applied Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Al Ahsa 36428, Saudi Arabia
| | - Scott N. Dean
- Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA
| | - Shravani Bobde
- School of Systems Biology, George Mason University, Manassas, VA 20110, USA (S.B.)
| | - Gabriel G. Ascoli
- Aspiring Scientist Summer Internship Program, George Mason University, Manassas, VA 20110, USA
| | - Monique L. van Hoek
- School of Systems Biology, George Mason University, Manassas, VA 20110, USA (S.B.)
- Center for Infectious Disease Research, George Mason University, Manassas, VA 20110, USA
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Boulesnam SL, Hamaidi-Chergui F, Benamara M, Azrou S. Phenotypical Comparison between Environmental and Clinical Acinetobacter baumannii Strains Isolated from an Intensive Care Unit. Malays J Med Sci 2023; 30:85-93. [PMID: 37655144 PMCID: PMC10467598 DOI: 10.21315/mjms2023.30.4.8] [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: 07/29/2022] [Accepted: 12/05/2022] [Indexed: 09/02/2023] Open
Abstract
Background Acinetobacter baumannii (A. baumannii) causes a variety of nosocomial infections that mainly affect critically ill patients in intensive care units (ICUs). The objective of this study was to assess the prevalence of A. baumannii in the ICU environment and evaluate the antibiotic resistance and biofilm formation ability of the environmental isolates compared to those isolated from ICU patients simultaneously. Methods A total of 166 non-duplicate ICU samples (80 environmental and 86 clinical) were collected between January 2019 and January 2020. Antimicrobial susceptibility detection was determined using the disc diffusion method, and the strains were evaluated for the minimum inhibitory concentration (MIC) of imipenem (IMP) using broth microdilution or metallo-β-lactamase (MBL) detection according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The isolates' capacity to produce biofilms was evaluated using the tube method and the crystal violet microtitre plate-based method. Results A. baumannii was identified in 25 (31.25%) environmental and 30 (34.88%) clinical samples, and beds were the most infected (60%). Both types of isolate demonstrated a rate surpassing 80% resistance to the tested antibiotics. Phenotypically, the environmental and clinical strains were found to be MBL producers. Fourteen environmental (56%) and 15 clinical (50%) strains were found to be moderate biofilm producers, indicating that each isolate has a high biofilm-forming capacity. Conclusion These results show that the spread of multidrug-resistant (MDR) A. baumannii in an ICU setting emphasises the necessity of disinfecting and cleaning medical devices and surfaces to prevent and restrict cross-transmission. Intensive surveillance and infection control methods are also of paramount importance.
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Affiliation(s)
- Saliha Lydia Boulesnam
- Biotechnology, Environment and Health Laboratory, Biology Department, Blida 1 University, Algeria
| | - Fella Hamaidi-Chergui
- Biotechnology, Environment and Health Laboratory, Biology Department, Blida 1 University, Algeria
| | | | - Sihem Azrou
- Microbiology Laboratory, Faculty of Pharmacy of Algiers, Algeria
- Central Laboratory, Beni Messous EPH, Algeria
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Cavallo I, Oliva A, Pages R, Sivori F, Truglio M, Fabrizio G, Pasqua M, Pimpinelli F, Di Domenico EG. Acinetobacter baumannii in the critically ill: complex infections get complicated. Front Microbiol 2023; 14:1196774. [PMID: 37425994 PMCID: PMC10325864 DOI: 10.3389/fmicb.2023.1196774] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/05/2023] [Indexed: 07/11/2023] Open
Abstract
Acinetobacter baumannii is increasingly associated with various epidemics, representing a serious concern due to the broad level of antimicrobial resistance and clinical manifestations. During the last decades, A. baumannii has emerged as a major pathogen in vulnerable and critically ill patients. Bacteremia, pneumonia, urinary tract, and skin and soft tissue infections are the most common presentations of A. baumannii, with attributable mortality rates approaching 35%. Carbapenems have been considered the first choice to treat A. baumannii infections. However, due to the widespread prevalence of carbapenem-resistant A. baumannii (CRAB), colistin represents the main therapeutic option, while the role of the new siderophore cephalosporin cefiderocol still needs to be ascertained. Furthermore, high clinical failure rates have been reported for colistin monotherapy when used to treat CRAB infections. Thus, the most effective antibiotic combination remains disputed. In addition to its ability to develop antibiotic resistance, A. baumannii is also known to form biofilm on medical devices, including central venous catheters or endotracheal tubes. Thus, the worrisome spread of biofilm-producing strains in multidrug-resistant populations of A. baumannii poses a significant treatment challenge. This review provides an updated account of antimicrobial resistance patterns and biofilm-mediated tolerance in A. baumannii infections with a special focus on fragile and critically ill patients.
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Affiliation(s)
- Ilaria Cavallo
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Alessandra Oliva
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Rebecca Pages
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Francesca Sivori
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Mauro Truglio
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Giorgia Fabrizio
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Martina Pasqua
- Department of Biology and Biotechnology "C. Darwin" Sapienza University of Rome, Rome, Italy
| | - Fulvia Pimpinelli
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Enea Gino Di Domenico
- Department of Biology and Biotechnology "C. Darwin" Sapienza University of Rome, Rome, Italy
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Sarkar P, De K, Modi M, Dhanda G, Priyadarshini R, Bandow JE, Haldar J. Next-generation membrane-active glycopeptide antibiotics that also inhibit bacterial cell division. Chem Sci 2023; 14:2386-2398. [PMID: 36873852 PMCID: PMC9977398 DOI: 10.1039/d2sc05600c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 01/02/2023] [Indexed: 01/09/2023] Open
Abstract
Resistance to vancomycin, a life-saving drug against Gram-positive bacterial infections necessitates developing alternative therapeutics. Herein, we report vancomycin derivatives that assimilate mechanisms beyond d-Ala-d-Ala binding. The role of hydrophobicity towards the structure and function of the membrane-active vancomycin showed that alkyl-cationic substitutions favored broad-spectrum activity. The lead molecule, VanQAmC10 delocalized the cell division protein MinD in Bacillus subtilis, implying an impact on bacterial cell division. Further examination of wild-type, GFP-FtsZ, or GFP-FtsI producing- and ΔamiAC mutants of Escherichia coli revealed filamentous phenotypes and delocalization of the FtsI protein. The findings indicate that VanQAmC10 also inhibits bacterial cell division, a property previously unknown for glycopeptide antibiotics. The conjunction of multiple mechanisms contributes to its superior efficacy against metabolically active and inactive bacteria, wherein vancomycin is ineffective. Additionally, VanQAmC10 exhibits high efficacy against methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii in mouse models of infection.
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Affiliation(s)
- Paramita Sarkar
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) Jakkur Bengaluru 560064 Karnataka India +91 802208 2565
| | - Kathakali De
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) Jakkur Bengaluru 560064 Karnataka India +91 802208 2565
| | - Malvika Modi
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University Dadri 201314 UP India
| | - Geetika Dhanda
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) Jakkur Bengaluru 560064 Karnataka India +91 802208 2565
| | - Richa Priyadarshini
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University Dadri 201314 UP India
| | - Julia E Bandow
- Applied Microbiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Universitätsstraße 150 44780 Bochum Germany
| | - Jayanta Haldar
- Antimicrobial Research Laboratory, New Chemistry Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) Jakkur Bengaluru 560064 Karnataka India +91 802208 2565
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Kong X, Chen T, Guo L, Zhou Y, Lu P, Xiao Y. Phenotypic and genomic comparison of dominant and nondominant sequence-type of Acinetobacter baumannii isolated in China. Front Cell Infect Microbiol 2023; 13:1118285. [PMID: 36891157 PMCID: PMC9986592 DOI: 10.3389/fcimb.2023.1118285] [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: 12/07/2022] [Accepted: 01/31/2023] [Indexed: 02/22/2023] Open
Abstract
A. baumannii is a common clinical pathogen that often causes pneumonia and bloodstream infections in ICU patients. Sequence types (ST) are used to investigate the distribution and spread of A. baumannii. Biological characteristics such as virulence and resistance may play a role in A. baumannii becoming a specific dominant ST(DST,ST191, ST195 and ST208) strain. To characterize the biological, genetic, and transcriptomic differences between the DST and non-dominant ST(NST,ST462 and ST547,etc.) strains in A. baumannii, we performed several biological experiments and genetic, and transcriptomic analyses. The DST group displayed more resistance ability to desiccation, oxidation, multiple antibiotics, and complement killing than the NST group. However, the latter had higher biofilm formation ability than the former. The genomic analysis showed the DST group exhibited more capsule-related and aminoglycoside-resistant genes. Besides, GO analysis indicated that functions involved in lipid biosynthetic, transport, and the metabolic process were up-regulated in the DST group, while KEGG analysis manifested that the two-component system related to potassium ion transport and pili were down-regulated. In short, resistance to desiccation, oxidation, multiple antibiotics, and serum complement killing are important reasons for the formation of DST. Genes related to capsule synthesis and lipid biosynthesis and metabolism play an important role at the molecular level in the formation of DST.
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Affiliation(s)
- Xiaoyang Kong
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Tao Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lihua Guo
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yanzi Zhou
- Department of Rheumatology, Affiliated Hangzhou First People’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Ping Lu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yonghong Xiao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, China
- *Correspondence: Yonghong Xiao,
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Alamneh YA, Antonic V, Garry B, Pucci MJ, Abu-Taleb R, Shearer JP, Demons ST, Getnet D, Swierczewski BE, Lister T, Zurawski DV. Minocycline and the SPR741 Adjuvant Are an Efficacious Antibacterial Combination for Acinetobacter baumannii Infections. Antibiotics (Basel) 2022; 11:antibiotics11091251. [PMID: 36140032 PMCID: PMC9495173 DOI: 10.3390/antibiotics11091251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 09/01/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
Antibiotic resistance, when it comes to bacterial infections, is not a problem that is going to disappear anytime soon. With the lack of larger investment in novel antibiotic research and the ever-growing increase of resistant isolates amongst the ESKAPEE pathogens (Enterobacter cloacae, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterococcus sp., and Escherichia coli), it is inevitable that more and more infections caused by extensively drug-resistant (XDR) and pandrug-resistant (PDR) strains will arise. One strategy to counteract the growing threat is to use antibiotic adjuvants, a drug class that on its own lacks significant antibiotic activity, but when mixed with another antibiotic, can potentiate increased killing of bacteria. Antibiotic adjuvants have various mechanisms of action, but polymyxins and polymyxin-like molecules can disrupt the Gram-negative outer membrane and allow other drugs better penetration into the bacterial periplasm and cytoplasm. Previously, we showed that SPR741 had this adjuvant effect with regard to rifampin; however, rifampin is often not used clinically because of easily acquired resistance. To find additional, appropriate clinical partners for SPR741 with respect to pulmonary and wound infections, we investigated tetracyclines and found a previously undocumented synergy with minocycline in vitro and in vivo in murine models of infection.
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Affiliation(s)
- Yonas A. Alamneh
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Vlado Antonic
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Brittany Garry
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | | | - Rania Abu-Taleb
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Jonathan P. Shearer
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Samandra T. Demons
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Derese Getnet
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Brett E. Swierczewski
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Troy Lister
- Spero Therapeutics, Inc., Cambridge, MA 02139, USA
| | - Daniel V. Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
- Correspondence: ; Tel.: +1-301-319-3110; Fax: +1-301-319-9801
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Zhou J, Ventura CJ, Yu Y, Gao W, Fang RH, Zhang L. Biomimetic Neutrophil Nanotoxoids Elicit Potent Immunity against Acinetobacter baumannii in Multiple Models of Infection. NANO LETTERS 2022; 22:7057-7065. [PMID: 35998891 PMCID: PMC9971251 DOI: 10.1021/acs.nanolett.2c01948] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Acinetobacter baumannii is a leading cause of antibiotic-resistant nosocomial infections with high mortality rates, yet there is currently no clinically approved vaccine formulation. During the onset of A. baumannii infection, neutrophils are the primary responders and play a major role in resisting the pathogen. Here, we design a biomimetic nanotoxoid for antivirulence vaccination by using neutrophil membrane-coated nanoparticles to safely capture secreted A. baumannii factors. Vaccination with the nanotoxoid formulation rapidly mobilizes innate immune cells and promotes pathogen-specific adaptive immunity. In murine models of pneumonia, septicemia, and superficial wound infection, immunization with the nanovaccine offers significant protection, improving survival and reducing signs of acute inflammation. Lower bacterial burdens are observed in vaccinated animals regardless of the infection route. Altogether, neutrophil nanotoxoids represent an effective platform for eliciting multivalent immunity to protect against multidrug-resistant A. baumannii in a wide range of disease conditions.
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Affiliation(s)
- Jiarong Zhou
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, U.S.A
| | - Christian J. Ventura
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, U.S.A
| | - Yiyan Yu
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, U.S.A
| | - Weiwei Gao
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, U.S.A
| | - Ronnie H. Fang
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, U.S.A
| | - Liangfang Zhang
- Department of NanoEngineering, Chemical Engineering Program, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, U.S.A
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11
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Golestani F, Malekan M, Rasooli I, Jahangiri A, Ramezanalizadeh F, Chaudhuri S, Farshchi Andisi V, Schryvers AB. Immunogenicity of loop 3 of Omp34 from A. Baumannii in loopless C-lobe of TbpB of N. meningitidis. Int Immunopharmacol 2022; 110:109013. [PMID: 35785727 DOI: 10.1016/j.intimp.2022.109013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/17/2022] [Accepted: 06/27/2022] [Indexed: 12/29/2022]
Abstract
Acinetobacter baumannii is a common causative agent of nosocomial infections, with a mortality rate of 43% in infected patients. Due to the emergence of multidrug-resistant (MDR) strains, vaccine development has become necessary. Since the 34 kDa outer membrane protein Omp34 has been identified as a potential vaccine target, we implemented a hybrid antigen approach to target its extracellular loops. Using bioinformatic and structural analyses, we selected Loop 3 from Omp34 and displayed it on the loopless C-lobe (LCL) of TbpB of Neisseria meningitidis. The hybrid antigen and the LCL were produced and used to immunize mice for passive and active immunization and challenge experiments in which the reactivity of the sera was assessed by ELISAs, the bacterial load in the tissues measured and the survival of immunized mice compared. LCL was ineffective in immunization against A. baumannii thus the resulting immunity was due to the presence of Omp34 loop 3. It resulted in increased survival and a reduced bacterial load in the tissues compared to the control groups. The findings indicate that the immunogenicity of Omp34 loops can induce protection against A. baumannii infection, and it could probably be used as a vaccine candidate to control the pathogenesis of A. baumannii.
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Affiliation(s)
| | | | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran; Molecular Microbiology Research Center and Department of Biology, Shahed University, Tehran, Iran.
| | - Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems biology and poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | | | - Somshukla Chaudhuri
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Canada
| | - Vahid Farshchi Andisi
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Canada
| | - Anthony B Schryvers
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Canada
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12
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Lipocalin2 as a potential antibacterial drug against Acinetobacter baumannii infection. J Microbiol 2022; 60:444-449. [DOI: 10.1007/s12275-022-2007-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/10/2022] [Accepted: 02/22/2022] [Indexed: 10/18/2022]
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13
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Bergmann-Leitner ES, Bobrov AG, Bolton JS, Rouse MD, Heyburn L, Pavlovic R, Garry BI, Alamneh Y, Long J, Swierczewski B, Tyner S, Getnet D, Sajja VS, Antonic V. Blast Waves Cause Immune System Dysfunction and Transient Bone Marrow Failure in a Mouse Model. Front Bioeng Biotechnol 2022; 10:821169. [PMID: 35392409 PMCID: PMC8980552 DOI: 10.3389/fbioe.2022.821169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/23/2022] [Indexed: 11/29/2022] Open
Abstract
Explosive devices, either conventional or improvised, are common sources of injuries during combat, civil unrest, and terror attacks, resulting in trauma from exposure to blast. A blast wave (BW), a near-instantaneous rise in pressure followed by a negative pressure, propagates through the body in milliseconds and can affect physiology for days/months after exposure. Epidemiological data show that blast-related casualties result in significantly higher susceptibility to wound infections, suggesting long-lasting immune modulatory effects from blast exposure. The mechanisms involved in BW-induced immune changes are poorly understood. We evaluated the effects of BW on the immune system using an established murine model. Animals were exposed to BWs (using an Advanced Blast Simulator), followed by longitudinally sampling for 14 days. Blood, bone marrow, and spleen were analyzed for changes in the 1) complete blood count (CBC), and 2) composition of bone marrow cells (BMC) and splenocytes, and 3) concentrations of systemic cytokines/chemokines. Our data demonstrate that BW results in transient bone marrow failure and long-term changes in the frequency and profile of progenitor cell populations. Viability progressively decreased in hematopoietic stem cells and pluripotent progenitor cells. Significant decrease of CD4+ T cells in the spleen indicates reduced functionality of adaptive immune system. Dynamic changes in the concentrations of several cytokines and chemokines such as IL-1α and IL-17 occurred potentially contributing to dysregulation of immune response after trauma. This work lays the foundation for identifying the potential mechanisms behind BW’s immunosuppressive effects to inform the recognition of this compromised status is crucial for the development of therapeutic interventions for infections to reduce recovery time of wounded patients injured by explosive devices.
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Affiliation(s)
- Elke S. Bergmann-Leitner
- Biologics Research and Development, Walter Reed Army Institute of Research, Silver Spring, MD, United States
- *Correspondence: Elke S. Bergmann-Leitner, ; Venkatasivasai S. Sajja, ; Vlado Antonic,
| | - Alexander G. Bobrov
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Jessica S. Bolton
- Biologics Research and Development, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Michael D. Rouse
- Wound Infections Department, Naval Research Medical Center, Silver Spring, MD, United States
- Henry M. Jackson Foundation, Rockville, MD, United States
| | - Lanier Heyburn
- Blast Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Radmila Pavlovic
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Brittany I. Garry
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Yonas Alamneh
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Joseph Long
- Blast Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Brett Swierczewski
- Bacterial Disease Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Stuart Tyner
- Military Infectious Diseases Research Program, Frederick, MD, United States
| | - Derese Getnet
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Venkatasivasai S. Sajja
- Blast Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
- *Correspondence: Elke S. Bergmann-Leitner, ; Venkatasivasai S. Sajja, ; Vlado Antonic,
| | - Vlado Antonic
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD, United States
- *Correspondence: Elke S. Bergmann-Leitner, ; Venkatasivasai S. Sajja, ; Vlado Antonic,
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14
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Li Y, Wang S, Xing Z, Niu Y, Liao Z, Lu Y, Qiu J, Zhang J, Wang C, Dong L. Destructing biofilms by cationic dextran through phase transition. Carbohydr Polym 2022; 279:118778. [PMID: 34980345 DOI: 10.1016/j.carbpol.2021.118778] [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: 07/28/2021] [Revised: 09/28/2021] [Accepted: 10/10/2021] [Indexed: 11/16/2022]
Abstract
Eliminating biofilms from infected tissue presents one of the most challenging issues in clinical treatment of chronic wounds. In biofilms, the extracellular polymeric substances (EPS) form gel structures by electrostatic forces between macromolecules. We hypothesized that cationic polymers could induce the gel-to-sol phase transition of the network, leading to biofilms disruptions. We first validated this assumption by using polyethyleneimine (PEI) as a model molecule, and further synthesized two cationic dextrans with high biodegradability for in vitro and in vivo evaluation. All the cationic polymers could destruct Pseudomonas aeruginosa (P. aeruginosa) biofilms. Treating biofilm with cationic dextrans significantly enhanced the bacterial antibiotic sensitivity. When tested in a biofilm-presenting mouse wound healing model, the cationic dextrans efficiently controlled infection, and accelerated the healing process. Our findings suggest that devising cationic polymers to trigger phase transition of biofilm is an effective, straightforward, and perhaps generic strategy for anti-bacterial therapies.
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Affiliation(s)
- Yurong Li
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210093, China
| | - Shaocong Wang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210093, China
| | - Zhen Xing
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210093, China
| | - Yiming Niu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China
| | - Zhencheng Liao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China
| | - Yang Lu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210093, China
| | - Junni Qiu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210093, China
| | - Junfeng Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210093, China.
| | - Chunming Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau SAR, China.
| | - Lei Dong
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210093, China.
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15
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Ruamsap N, Thomas CS, Imerbsin R, Reed MC, Gonwong S, Lurchachaiwong W, Islam D, Wojnarski M, Vesely BA, Lugo-Roman LA, Waters NC, Zurawski DV, Demons ST. Chronic Wound Infection Model of Acinetobacter baumannii in Outbred Mice. Mil Med 2022; 188:usac020. [PMID: 35134989 DOI: 10.1093/milmed/usac020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/05/2022] [Accepted: 02/02/2022] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION We established a murine wound infection model with doxycycline treatment against multidrug-resistant Acinetobacter baumannii (AB5075) in Institute of Cancer Research (ICR) outbred mice. METHODS Using three groups of neutropenic ICR mice, two full-thickness dorsal dermal wounds (6 mm diameter) were made on each mouse. In two groups, wounds were inoculated with 7.0 × 104 colony-forming units of AB5075. Of these two groups, one received a 6-day regimen of doxycycline while the other was sham treated with phosphate-buffered saline as placebo control. Another uninfected/untreated group served as a control. Wound closure, clinical symptoms, bacterial burden in wound beds and organs, and wound histology were investigated. RESULTS Doxycycline-treated wounds completely healed by day 21, but untreated, infected wounds failed to heal. Compared to controls, wound infections without treatment resulted in significant reductions in body weight and higher bacterial loads in wound beds, lung, liver, and spleen by day 7. Histological evaluation of wounds on day 21 revealed ulcerated epidermis, muscle necrosis, and bacterial presence in untreated wounds, while wounds treated with doxycycline presented intact epidermis. CONCLUSIONS Compared to the previously developed BALB/c dermal wound model, this study demonstrates that the mouse strain selected impacts wound severity and resolution. Furthermore, this mouse model accommodates two dorsal wounds rather than only one. These variations offer investigators increased versatility when designing future studies of wound infection. In conclusion, ICR mice are a viable option as a model of dermal wound infection. They accommodate two simultaneous dorsal wounds, and upon infection, these wounds follow a different pattern of resolution compared to BALB/c mice.
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16
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Aswathanarayan JB, Rao P, HM S, GS S, Rai RV. Biofilm-Associated Infections in Chronic Wounds and Their Management. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022. [DOI: 10.1007/5584_2022_738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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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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Novel lipophosphonoxin-loaded polycaprolactone electrospun nanofiber dressing reduces Staphylococcus aureus induced wound infection in mice. Sci Rep 2021; 11:17688. [PMID: 34480072 PMCID: PMC8417216 DOI: 10.1038/s41598-021-96980-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/18/2021] [Indexed: 01/24/2023] Open
Abstract
Active wound dressings are attracting extensive attention in soft tissue repair and regeneration, including bacteria-infected skin wound healing. As the wide use of antibiotics leads to drug resistance we present here a new concept of wound dressings based on the polycaprolactone nanofiber scaffold (NANO) releasing second generation lipophosphonoxin (LPPO) as antibacterial agent. Firstly, we demonstrated in vitro that LPPO released from NANO exerted antibacterial activity while not impairing proliferation/differentiation of fibroblasts and keratinocytes. Secondly, using a mouse model we showed that NANO loaded with LPPO significantly reduced the Staphylococcus aureus counts in infected wounds as evaluated 7 days post-surgery. Furthermore, the rate of degradation and subsequent LPPO release in infected wounds was also facilitated by lytic enzymes secreted by inoculated bacteria. Finally, LPPO displayed negligible to no systemic absorption. In conclusion, the composite antibacterial NANO-LPPO-based dressing reduces the bacterial load and promotes skin repair, with the potential to treat wounds in clinical settings.
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19
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Askari P, Namaei MH, Ghazvini K, Hosseini M. In vitro and in vivo toxicity and antibacterial efficacy of melittin against clinical extensively drug-resistant bacteria. BMC Pharmacol Toxicol 2021; 22:42. [PMID: 34261542 PMCID: PMC8281584 DOI: 10.1186/s40360-021-00503-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 05/21/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Melittin is one of the most studied antimicrobial peptides, and several in vitro experiments have demonstrated its antibacterial efficacy. However, there is evidence showing melittin has non-promising effects such as cytotoxicity and hemolysis. Therefore, concerns about unwanted collateral toxicity of melittin lie ahead in the path toward its clinical development. With these considerations, the present study aimed to fill the gap between in vitro and in vivo studies. METHODS In the first step, in vitro toxicity profile of melittin was assessed using cytotoxicity and hemolysis tests. Next, a maximum intraperitoneal (i.p.) sub-lethal dose was determined using BALB/c mice. Besides toxicity, antimicrobial efficacy of melittin against extensively drug-resistant (XDR) Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), and KPC-producing Klebsiella pneumonia (KPC-KP) pathogens were tested using both in vitro and in vivo methods. RESULTS Melittin showed extensive hemolysis (HD50 = 0.44 µg/mL), and cytotoxicity (IC50 = 6.45 µg/mL) activities with i.p. LD50 value of 4.98 mg/kg in BALB/c mice. In vitro antimicrobial evaluation showed melittin MIC range from 8 to 32 µg/mL for the studied pathogens. Treatment of infected mice with repeated sub-lethal doses of melittin (2.4 mg/kg) displayed no beneficial effect on their survival and peritoneal bacterial loads. CONCLUSIONS These results indicate that melittin at its safe dose could not exhibit antimicrobial activity, which hinders its application in clinical practice.
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Affiliation(s)
- Parvin Askari
- Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Hasan Namaei
- Infectious Diseases Research Center, Birjand University of Medical Sciences, Mashhad, Iran
| | - Kiarash Ghazvini
- Department of Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
- Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Mehran Hosseini
- Department of Anatomical Sciences, Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran.
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20
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Stanbro J, Park JM, Bond M, Stockelman MG, Simons MP, Watters C. Topical Delivery of Lactobacillus Culture Supernatant Increases Survival and Wound Resolution in Traumatic Acinetobacter baumannii Infections. Probiotics Antimicrob Proteins 2021; 12:809-818. [PMID: 31741312 DOI: 10.1007/s12602-019-09603-z] [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: 12/18/2022]
Abstract
Species of Lactobacillus have been proposed as potential candidates for treating wound infections due to their ability to lower pH, decrease inflammation, and release antimicrobial compounds. This study investigated the impact of lactobacilli (Lactobacillus acidophilus ATCC 4356, Lactobacillus casei ATCC 393, Lactobacillus reuteri ATCC 23272) secreted products on wound pathogens in vitro and in a murine wound infection model. Evaluation of 1-5 day lactobacilli conditioned media (CM) revealed maximal inhibition against wound pathogens using the 5-day CM. The minimum inhibitory concentration (MIC) of 5-day Lactobacillus CMs was tested by diluting CM in Mueller-Hinton (MH) broth from 0 to 25% and was found to be 12.5% for A. baumannii. Concentrating the CM to 10× with a 3 kDa centrifuge filter decreased the CM MIC to 6.25-12.5% for A. baumannii planktonic cells. Minimal impact of 5-day CMs was observed against bacterial biofilms. No toxicity was observed when these Lactobacillus CMs were injected into Galleria melonella waxworms. For the murine A. baumannii wound infection studies, improved survival was observed following topical treatment with L. acidophilus ATCC 4356 or L. reuteri ATCC 23272, while L. reuteri ATCC 23272 treatment alone improved wound resolution. Overall, this study suggests that the topical application of certain Lactobacillus species byproducts could be effective against gram-negative multi-drug resistant (MDR) wound pathogens, such as A. baumannii.
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Affiliation(s)
- Josh Stanbro
- Wound Infections Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Ju Me Park
- Wound Infections Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Matthew Bond
- Wound Infections Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Michael G Stockelman
- Wound Infections Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Mark P Simons
- Wound Infections Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Chase Watters
- Wound Infections Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA.
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21
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Pompilio A, Scribano D, Sarshar M, Di Bonaventura G, Palamara AT, Ambrosi C. Gram-Negative Bacteria Holding Together in a Biofilm: The Acinetobacter baumannii Way. Microorganisms 2021; 9:microorganisms9071353. [PMID: 34206680 PMCID: PMC8304980 DOI: 10.3390/microorganisms9071353] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 12/24/2022] Open
Abstract
Bacterial biofilms are a serious public-health problem worldwide. In recent years, the rates of antibiotic-resistant Gram-negative bacteria associated with biofilm-forming activity have increased worrisomely, particularly among healthcare-associated pathogens. Acinetobacter baumannii is a critically opportunistic pathogen, due to the high rates of antibiotic resistant strains causing healthcare-acquired infections (HAIs). The clinical isolates of A. baumannii can form biofilms on both biotic and abiotic surfaces; hospital settings and medical devices are the ideal environments for A. baumannii biofilms, thereby representing the main source of patient infections. However, the paucity of therapeutic options poses major concerns for human health infections caused by A. baumannii strains. The increasing number of multidrug-resistant A. baumannii biofilm-forming isolates in association with the limited number of biofilm-eradicating treatments intensify the need for effective antibiofilm approaches. This review discusses the mechanisms used by this opportunistic pathogen to form biofilms, describes their clinical impact, and summarizes the current and emerging treatment options available, both to prevent their formation and to disrupt preformed A. baumannii biofilms.
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Affiliation(s)
- Arianna Pompilio
- Center for Advanced Studies and Technology (CAST), Department of Medical, Oral and Biotechnological Sciences, Service of Clinical Microbiology, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (A.P.); (G.D.B.)
| | - Daniela Scribano
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy;
- Dani Di Giò Foundation-Onlus, 00193 Rome, Italy
| | - Meysam Sarshar
- Research Laboratories, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy;
| | - Giovanni Di Bonaventura
- Center for Advanced Studies and Technology (CAST), Department of Medical, Oral and Biotechnological Sciences, Service of Clinical Microbiology, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (A.P.); (G.D.B.)
| | - Anna Teresa Palamara
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy;
- Laboratory Affiliated to Institute Pasteur Italia-Cenci Bolognetti Foundation, Department of Public Health and Infectious Diseases, Sapienza University of Rome, 00185 Rome, Italy
| | - Cecilia Ambrosi
- Department of Human Sciences and Promotion of the Quality of Life, San Raffaele Open University, IRCCS, 00166 Rome, Italy
- Correspondence:
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22
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Engeman E, Freyberger HR, Corey BW, Ward AM, He Y, Nikolich MP, Filippov AA, Tyner SD, Jacobs AC. Synergistic Killing and Re-Sensitization of Pseudomonas aeruginosa to Antibiotics by Phage-Antibiotic Combination Treatment. Pharmaceuticals (Basel) 2021; 14:ph14030184. [PMID: 33668899 PMCID: PMC7996583 DOI: 10.3390/ph14030184] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 02/16/2021] [Accepted: 02/22/2021] [Indexed: 12/30/2022] Open
Abstract
Multidrug-resistant (MDR) Pseudomonas aeruginosa infections pose a serious health threat. Bacteriophage-antibiotic combination therapy is a promising candidate for combating these infections. A 5-phage P. aeruginosa cocktail, PAM2H, was tested in combination with antibiotics (ceftazidime, ciprofloxacin, gentamicin, meropenem) to determine if PAM2H enhances antibiotic activity. Combination treatment in vitro resulted in a significant increase in susceptibility of MDR strains to antibiotics. Treatment with ceftazidime (CAZ), meropenem, gentamicin, or ciprofloxacin in the presence of the phage increased the number of P. aeruginosa strains susceptible to these antibiotics by 63%, 56%, 31%, and 81%, respectively. Additionally, in a mouse dorsal wound model, seven of eight mice treated with a combination of CAZ and PAM2H for three days had no detectable bacteria remaining in their wounds on day 4, while all mice treated with CAZ or PAM2H alone had ~107 colony forming units (CFU) remaining in their wounds. P. aeruginosa recovered from mouse wounds post-treatment showed decreased virulence in a wax worm model, and DNA sequencing indicated that the combination treatment prevented mutations in genes encoding known phage receptors. Treatment with PAM2H in combination with antibiotics resulted in the re-sensitization of P. aeruginosa to antibiotics in vitro and a synergistic reduction in bacterial burden in vivo.
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Affiliation(s)
- Emily Engeman
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN 37831, USA
| | - Helen R. Freyberger
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
- ICON plc, Ellicott City, MD 21043, USA
| | - Brendan W. Corey
- Multidrug-Resistant Organism Repository and Surveillance Network, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA;
| | - Amanda M. Ward
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
- ICON plc, Ellicott City, MD 21043, USA
| | - Yunxiu He
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
- ICON plc, Ellicott City, MD 21043, USA
| | - Mikeljon P. Nikolich
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
| | - Andrey A. Filippov
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
- ICON plc, Ellicott City, MD 21043, USA
- Correspondence:
| | - Stuart D. Tyner
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
| | - Anna C. Jacobs
- Center for Infectious Diseases Research, Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (E.E.); (H.R.F.); (A.M.W.); (Y.H.); (M.P.N.); (S.D.T.); (A.C.J.)
- ICON plc, Ellicott City, MD 21043, USA
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Dollery SJ, Zurawski DV, Gaidamakova EK, Matrosova VY, Tobin JK, Wiggins TJ, Bushnell RV, MacLeod DA, Alamneh YA, Abu-Taleb R, Escatte MG, Meeks HN, Daly MJ, Tobin GJ. Radiation-Inactivated Acinetobacter baumannii Vaccine Candidates. Vaccines (Basel) 2021; 9:vaccines9020096. [PMID: 33514059 PMCID: PMC7912630 DOI: 10.3390/vaccines9020096] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 12/20/2022] Open
Abstract
Acinetobacter baumannii is a bacterial pathogen that is often multidrug-resistant (MDR) and causes a range of life-threatening illnesses, including pneumonia, septicemia, and wound infections. Some antibiotic treatments can reduce mortality if dosed early enough before an infection progresses, but there are few other treatment options when it comes to MDR-infection. Although several prophylactic strategies have been assessed, no vaccine candidates have advanced to clinical trials or have been approved. Herein, we rapidly produced protective whole-cell immunogens from planktonic and biofilm-like cultures of A. baumannii, strain AB5075 grown using a variety of methods. After selecting a panel of five cultures based on distinct protein profiles, replicative activity was extinguished by exposure to 10 kGy gamma radiation in the presence of a Deinococcus antioxidant complex composed of manganous (Mn2+) ions, a decapeptide, and orthophosphate. Mn2+ antioxidants prevent hydroxylation and carbonylation of irradiated proteins, but do not protect nucleic acids, yielding replication-deficient immunogenic A. baumannii vaccine candidates. Mice were immunized and boosted twice with 1.0 × 107 irradiated bacterial cells and then challenged intranasally with AB5075 using two mouse models. Planktonic cultures grown for 16 h in rich media and biofilm cultures grown in static cultures underneath minimal (M9) media stimulated immunity that led to 80–100% protection.
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Affiliation(s)
- Stephen J. Dollery
- Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA; (J.K.T.); (T.J.W.); (R.V.B.); (D.A.M.); (G.J.T.)
- Correspondence:
| | - Daniel V. Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (D.V.Z.); (Y.A.A.); (R.A.-T.); (M.G.E.)
| | - Elena K. Gaidamakova
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (E.K.G.); (V.Y.M.); (M.J.D.)
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | - Vera Y. Matrosova
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (E.K.G.); (V.Y.M.); (M.J.D.)
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | - John K. Tobin
- Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA; (J.K.T.); (T.J.W.); (R.V.B.); (D.A.M.); (G.J.T.)
| | - Taralyn J. Wiggins
- Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA; (J.K.T.); (T.J.W.); (R.V.B.); (D.A.M.); (G.J.T.)
| | - Ruth V. Bushnell
- Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA; (J.K.T.); (T.J.W.); (R.V.B.); (D.A.M.); (G.J.T.)
| | - David A. MacLeod
- Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA; (J.K.T.); (T.J.W.); (R.V.B.); (D.A.M.); (G.J.T.)
| | - Yonas A. Alamneh
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (D.V.Z.); (Y.A.A.); (R.A.-T.); (M.G.E.)
| | - Rania Abu-Taleb
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (D.V.Z.); (Y.A.A.); (R.A.-T.); (M.G.E.)
| | - Mariel G. Escatte
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (D.V.Z.); (Y.A.A.); (R.A.-T.); (M.G.E.)
| | | | - Michael J. Daly
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; (E.K.G.); (V.Y.M.); (M.J.D.)
| | - Gregory J. Tobin
- Biological Mimetics, Inc., 124 Byte Drive, Frederick, MD 21702, USA; (J.K.T.); (T.J.W.); (R.V.B.); (D.A.M.); (G.J.T.)
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24
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Contamination of wounds with fecal bacteria in immuno-suppressed mice. Sci Rep 2020; 10:11494. [PMID: 32661287 PMCID: PMC7359036 DOI: 10.1038/s41598-020-68323-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 06/15/2020] [Indexed: 12/30/2022] Open
Abstract
Immunocompromised patients are predisposed to chronically infected wounds. Especially ulcers in the dorsal region often experience secondary polymicrobial infections. However, current wound infection models mostly use single-strain bacteria. To mimic clinically occurring infections caused by fecal contamination in immunocompromised/immobile patients, which differ significantly from single-strain infections, the present study aimed at the establishment of a new mouse model using infection by fecal bacteria. Dorsal circular excision wounds in immunosuppressed mice were infected with fecal slurry solution in several dilutions up to 1:8,000. Impact of immunosuppressor, bacterial load and timing on development of wound infections was investigated. Wounds were analyzed by scoring, 3D imaging and swab analyses. Autofluorescence imaging was not successful. Dose-finding of cyclophosphamide-induced immunosuppression was necessary for establishment of bacterial wound infections. Infection with fecal slurry diluted 1:166 to 1:400 induced significantly delayed wound healing (p < 0.05) without systemic reactions. Swab analyses post-infection matched the initial polymicrobial suspension. The customized wound score confirmed significant differences between the groups (p < 0.05). Here we report the establishment of a simple, new mouse model for clinically occurring wound infections by fecal bacteria and the evaluation of appropriate wound analysis methods. In the future, this model will provide a suitable tool for the investigation of complex microbiological interactions and evaluation of new therapeutic approaches.
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De Oliveira DMP, Forde BM, Kidd TJ, Harris PNA, Schembri MA, Beatson SA, Paterson DL, Walker MJ. Antimicrobial Resistance in ESKAPE Pathogens. Clin Microbiol Rev 2020; 23:788-99. [PMID: 32404435 DOI: 10.1111/imb.12124] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.
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Affiliation(s)
- David M P De Oliveira
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Brian M Forde
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Timothy J Kidd
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Patrick N A Harris
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
- UQ Centre for Clinical Research, The University of Queensland, QLD, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
| | - David L Paterson
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
- UQ Centre for Clinical Research, The University of Queensland, QLD, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences, The University of Queensland, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, QLD, Australia
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26
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Salih AM, Ameen TM, Mahmood SO, Kakamad FH, Fathulla BL, Mikael TM, Habibullah IJ, Mohammed SH, Salih RQ, Kakamad SH. A dilemma of a case of Zenker diverticulum; leak or Acinetobacter baumannii?! A case report. Int J Surg Case Rep 2020; 71:274-276. [PMID: 32480337 PMCID: PMC7264014 DOI: 10.1016/j.ijscr.2020.05.004] [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: 04/01/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 11/29/2022] Open
Abstract
Zenker’s diverticulum is an acquired mucosal pulsion of the upper esophagus. Post operative leak and infection could lead to a dilemma to both surgeon and patient. We reported a case of Zenker’s diverticulum with a complicated postoperative course.
Introduction Zenker’s diverticulum is an acquired mucosal pulsion of the upper esophagus. The aim of this paper is to report a case of Zenker’s diverticulum with a complicated postoperative course including infection by Acinetobacter baumannii causing diagnostic as well as management dilemma. Case report A 43-year-old male complained from dysphagia for three months. Barium swallow revealed Zenker’s diverticulum. Under general anesthesia, the small Zenker’s diverticulum was ligated and myotomy was done. He developed erythematous swelling at the site of the operation. The patient was taken to the operation theater. The esophagus was tested, no trace of leak was found. The patient developed cardiac arrest. He was admitted to the intensive care unit and remained there for twenty eight days. Bronchial wash culture showed Acinetobacter baumannii. The patient was on antibiotic, supportive treatment and enteral feeding through nasogastric tube. After recovery he was extubated and barium swallow was done which was normal and showed no signs of leak. Three months after the operation, the patient was completely normal. Discussion This case had a positive culture for Acinetobacter baumannii. It is commonly accounted for nosocomial infections. It has been documented as a serious threat worldwide because of the emerging prevalence of multidrug resistant. However, an inadequate understanding of A. baumannii pathophysiology and ecosystem confines the progress of alternative therapeutic policies. In the current case, it was not clear either leak or Acinetobacter baumannii was the cause of deterioration. Conclusion Both esophageal leak and infection with Acinetobacter baumannii are fulminant debilitating conditions that could be managed with conservative strategies.
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Affiliation(s)
- Abdulwahid M Salih
- Faculty of Medical Sciences, School of Medicine, University of Sulaimani, François Mitterrand Street, Sulaimani, Kurdistan, Iraq; Smart Health Tower, Sulaimani, Madam Mitterrand Street, Kurdistan, Iraq
| | - Twana M Ameen
- Faculty of Medical Sciences, School of Medicine, University of Sulaimani, François Mitterrand Street, Sulaimani, Kurdistan, Iraq; Shar Teaching Hospital, Malik Mahmud Ring Road, Sulaimani, Kurdistan, Iraq
| | - Safeen O Mahmood
- Shar Teaching Hospital, Malik Mahmud Ring Road, Sulaimani, Kurdistan, Iraq
| | - Fahmi H Kakamad
- Faculty of Medical Sciences, School of Medicine, University of Sulaimani, François Mitterrand Street, Sulaimani, Kurdistan, Iraq; Smart Health Tower, Sulaimani, Madam Mitterrand Street, Kurdistan, Iraq; Kscien Organization for Scientific Research, Hamdi Street, Sulaimani, Kurdistan, Iraq.
| | - Bahman L Fathulla
- Sulaymaniyah Teaching Hospital, François Mitterrand Street, Kurdistan, Iraq
| | - Tomas M Mikael
- Smart Health Tower, Sulaimani, Madam Mitterrand Street, Kurdistan, Iraq; Kscien Organization for Scientific Research, Hamdi Street, Sulaimani, Kurdistan, Iraq
| | - Imad J Habibullah
- Smart Health Tower, Sulaimani, Madam Mitterrand Street, Kurdistan, Iraq; Kscien Organization for Scientific Research, Hamdi Street, Sulaimani, Kurdistan, Iraq
| | - Shvan H Mohammed
- Kscien Organization for Scientific Research, Hamdi Street, Sulaimani, Kurdistan, Iraq
| | - Rawezh Q Salih
- Smart Health Tower, Sulaimani, Madam Mitterrand Street, Kurdistan, Iraq; Kscien Organization for Scientific Research, Hamdi Street, Sulaimani, Kurdistan, Iraq
| | - Suhaib H Kakamad
- Kscien Organization for Scientific Research, Hamdi Street, Sulaimani, Kurdistan, Iraq
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Abstract
Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.
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28
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Ramirez MS, Bonomo RA, Tolmasky ME. Carbapenemases: Transforming Acinetobacter baumannii into a Yet More Dangerous Menace. Biomolecules 2020; 10:biom10050720. [PMID: 32384624 PMCID: PMC7277208 DOI: 10.3390/biom10050720] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 02/07/2023] Open
Abstract
Acinetobacter baumannii is a common cause of serious nosocomial infections. Although community-acquired infections are observed, the vast majority occur in people with preexisting comorbidities. A. baumannii emerged as a problematic pathogen in the 1980s when an increase in virulence, difficulty in treatment due to drug resistance, and opportunities for infection turned it into one of the most important threats to human health. Some of the clinical manifestations of A. baumannii nosocomial infection are pneumonia; bloodstream infections; lower respiratory tract, urinary tract, and wound infections; burn infections; skin and soft tissue infections (including necrotizing fasciitis); meningitis; osteomyelitis; and endocarditis. A. baumannii has an extraordinary genetic plasticity that results in a high capacity to acquire antimicrobial resistance traits. In particular, acquisition of resistance to carbapenems, which are among the antimicrobials of last resort for treatment of multidrug infections, is increasing among A. baumannii strains compounding the problem of nosocomial infections caused by this pathogen. It is not uncommon to find multidrug-resistant (MDR, resistance to at least three classes of antimicrobials), extensively drug-resistant (XDR, MDR plus resistance to carbapenems), and pan-drug-resistant (PDR, XDR plus resistance to polymyxins) nosocomial isolates that are hard to treat with the currently available drugs. In this article we review the acquired resistance to carbapenems by A. baumannii. We describe the enzymes within the OXA, NDM, VIM, IMP, and KPC groups of carbapenemases and the coding genes found in A. baumannii clinical isolates.
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Affiliation(s)
- Maria Soledad Ramirez
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA 92831, USA;
| | - Robert A. Bonomo
- Medical Service and GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH 44106, USA;
- Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Biochemistry, Proteomics and Bioinformatics; Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- WRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH 44106, USA
| | - Marcelo E. Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA 92831, USA;
- Correspondence: ; Tel.: +657-278-5263
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29
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Rouse MD, Stanbro J, Roman JA, Lipinski MA, Jacobs A, Biswas B, Regeimbal J, Henry M, Stockelman MG, Simons MP. Impact of Frequent Administration of Bacteriophage on Therapeutic Efficacy in an A. baumannii Mouse Wound Infection Model. Front Microbiol 2020; 11:414. [PMID: 32256472 PMCID: PMC7090133 DOI: 10.3389/fmicb.2020.00414] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/27/2020] [Indexed: 01/21/2023] Open
Abstract
The spread of multidrug antibiotic resistance (MDR) is a widely recognized crisis in the treatment of bacterial infections, including those occurring in military communities. Recently, the World Health Organization published its first ever list of antibiotic-resistant “priority pathogens” – a catalog of 12 families of bacteria that pose the greatest threat to human health with A. baumannii listed in the “Priority 1: Critical” category of pathogens. With the increasing prevalence of antibiotic resistance and limited development of new classes of antibiotics, alternative antimicrobial therapies are needed, with lytic bacteriophage (phage) specifically targeted against each of the high priority bacterial infections as a potential approach currently in development toward regulatory approval for clinical use. Balb/c mice were prophylactically administered PBS or phage selected against A. baumannii strain AB5075. After 3 weeks, mice were anesthetized, wounded (dorsal), and challenged topically with AB5075. Following infection, mice were subsequently treated with PBS or phage for three consecutive days, and evaluated for 3 weeks to assess the safety and efficacy of the phage treatment relative to the control. We assessed mortality, bacterial burden, time to wound closure, systemic and local cytokine profiles, alterations in host cellular immunity, and finally presence of neutralizing antibodies to the phage mixture. In our study, we found that prophylactic phage administration led to a significant reduction in monocyte-related cytokines in serum compared to mice given PBS. However, we detected no significant changes to circulating blood populations or immune cell populations of secondary lymphoid organs compared to PBS-treated mice. Following prophylactic phage administration, we detected a marked increase in total immunoglobulins in serum, particularly IgG2a and IgG2b. Furthermore, we determined that these antibodies were able to specifically target phage and effectively neutralize their ability to lyse their respective target. In regards to their therapeutic efficacy, administration of phage treatment effectively decreased wound size of mice infected with AB5075 without adverse effects. In conclusion, our data demonstrate that phage can serve as a safe and effective novel therapeutic agent against A. baumannii without adverse reactions to the host and pre-exposure to phage does not seem to adversely affect therapeutic efficacy. This study is an important proof of concept to support the efforts to develop phage as a novel therapeutic product for treatment of complex bacterial wound infections.
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Affiliation(s)
- Michael D Rouse
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Joshua Stanbro
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Jessica A Roman
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Michelle A Lipinski
- Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.,Naval Medical Research Center, Silver Spring, MD, United States
| | - Anna Jacobs
- Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Biswaijt Biswas
- Biological Defense Research Directorate, Naval Medical Research Center, Fort Detrick, MD, United States
| | | | - Matthew Henry
- Naval Medical Research Center, Silver Spring, MD, United States.,Biological Defense Research Directorate, Naval Medical Research Center, Fort Detrick, MD, United States
| | | | - Mark P Simons
- Naval Medical Research Center, Silver Spring, MD, United States
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30
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Hoffmann JP, Friedman JK, Wang Y, McLachlan JB, Sammarco MC, Morici LA, Roy CJ. In situ Treatment With Novel Microbiocide Inhibits Methicillin Resistant Staphylococcus aureus in a Murine Wound Infection Model. Front Microbiol 2020; 10:3106. [PMID: 32038549 PMCID: PMC6990143 DOI: 10.3389/fmicb.2019.03106] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/23/2019] [Indexed: 01/27/2023] Open
Abstract
Increased prevalence of antibiotic resistance in skin and soft tissue infections is a concerning public health challenge currently facing medical science. A combinatory, broad spectrum biocidal antiseptic has been developed (“ASP”) as a topically applied solution to potential resistant and polymicrobial infected wounds that may be encountered in this context. The ASP-105 designate was evaluated in vitro by determining the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), against different strains of methicillin-resistant Staphylococcus aureus (MRSA), resulting estimates of which approximated the positive control (bacitracin). To evaluate in vivo microbicide efficacy, we utilized a murine full thickness wound model to study bacterial infection and wound healing kinetics. Mice were experimentally wounded dorsally and infected with bioluminescent MRSA. The infected wound was splinted, dressed and treated topically with either ASP-105, vehicle (-control), or bacitracin. Bacterial burden and wound healing was monitored using an in vivo imaging system and evaluation of biofilm formation using scanning electron microscopy of wound dressing. Treatment with ASP-105 significantly reduced bacterial burdens in the first 3 days of infection and inhibited MRSA biofilm formation on the surgical dressing. Notably, treatment with ASP-105 resulted in a sterilizing effect of any detectable MRSA in nearly all (80%; 4/5) of treatment group. All mice receiving vehicle control developed highly MRSA-luminescent and purulent wound beds as a result of experimental infection. The ASP-105 therapy facilitated natural healing in the absence of MRSA infection. Results of this study suggests that that the novel “ASP” combinatory topical antiseptic can be used directly in wounds as a potent, broad-spectrum microbicide against drug resistant S. aureus without injury to the wound bed and impediment of natural restorative processes associated with wound healing. Further studies are warranted to test the effectiveness of this biocidal formulation against other recalcitrant bacterial and fungal pathogens in the context of serious wound infections, and to assess utility of use in both clinical and self-treat scenarios.
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Affiliation(s)
- Joseph P Hoffmann
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Jessica K Friedman
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA, United States
| | - Yihui Wang
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
| | - James B McLachlan
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Mimi C Sammarco
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA, United States
| | - Lisa A Morici
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Chad J Roy
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States.,Division of Microbiology, Tulane National Primate Research Center, Covington, LA, United States
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31
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Slade EA, Thorn RMS, Young A, Reynolds DM. An in vitro collagen perfusion wound biofilm model; with applications for antimicrobial studies and microbial metabolomics. BMC Microbiol 2019; 19:310. [PMID: 31888471 PMCID: PMC6937849 DOI: 10.1186/s12866-019-1682-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 12/11/2019] [Indexed: 12/12/2022] Open
Abstract
Background The majority of in vitro studies of medically relevant biofilms involve the development of biofilm on an inanimate solid surface. However, infection in vivo consists of biofilm growth on, or suspended within, the semi-solid matrix of the tissue, whereby current models do not effectively simulate the nature of the in vivo environment. This paper describes development of an in vitro method for culturing wound associated microorganisms in a system that combines a semi-solid collagen gel matrix with continuous flow of simulated wound fluid. This enables culture of wound associated reproducible steady state biofilms under conditions that more closely simulate the dynamic wound environment. To demonstrate the use of this model the antimicrobial kinetics of ceftazidime, against both mature and developing Pseudomonas aeruginosa biofilms, was assessed. In addition, we have shown the potential application of this model system for investigating microbial metabolomics by employing selected ion flow tube mass spectrometry (SIFT-MS) to monitor ammonia and hydrogen cyanide production by Pseudomonas aeruginosa biofilms in real-time. Results The collagen wound biofilm model facilitates growth of steady-state reproducible Pseudomonas aeruginosa biofilms under wound like conditions. A maximum biofilm density of 1010 cfu slide− 1 was achieved by 30 h of continuous culture and maintained throughout the remainder of the experiment. Treatment with ceftazidime at a clinically relevant dose resulted in a 1.2–1.6 log reduction in biofilm density at 72 h compared to untreated controls. Treatment resulted in loss of complex biofilm architecture and morphological changes to bacterial cells, visualised using confocal microscopy. When monitoring the biofilms using SIFT-MS, ammonia and hydrogen cyanide levels peaked at 12 h at 2273 ppb (±826.4) and 138 ppb (±49.1) respectively and were detectable throughout experimentation. Conclusions The collagen wound biofilm model has been developed to facilitate growth of reproducible biofilms under wound-like conditions. We have successfully used this method to: (1) evaluate antimicrobial efficacy and kinetics, clearly demonstrating the development of antimicrobial tolerance in biofilm cultures; (2) characterise volatile metabolite production by P. aeruginosa biofilms, demonstrating the potential use of this method in metabolomics studies.
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Affiliation(s)
- Elisabeth A Slade
- Centre for Research in Biosciences, University of the West of England, Bristol, UK
| | - Robin M S Thorn
- Centre for Research in Biosciences, University of the West of England, Bristol, UK
| | - Amber Young
- Scar Free Foundation Centre for Children's Burns Research, Bristol Royal Hospital for Children, Bristol, UK
| | - Darren M Reynolds
- Centre for Research in Biosciences, University of the West of England, Bristol, UK. .,University of the West of England, Frenchay Campus, Coldharbour Lane, Bristol, BS16 1QY, England.
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Application of Lactobacillus gasseri 63 AM supernatant to Pseudomonas aeruginosa-infected wounds prevents sepsis in murine models of thermal injury and dorsal excision. J Med Microbiol 2019; 68:1560-1572. [DOI: 10.1099/jmm.0.001066] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Chong KKL, Tay WH, Janela B, Yong AMH, Liew TH, Madden L, Keogh D, Barkham TMS, Ginhoux F, Becker DL, Kline KA. Enterococcus faecalis Modulates Immune Activation and Slows Healing During Wound Infection. J Infect Dis 2019; 216:1644-1654. [PMID: 29045678 PMCID: PMC5854026 DOI: 10.1093/infdis/jix541] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 10/13/2017] [Indexed: 01/13/2023] Open
Abstract
Enterococcus faecalis is one of the most frequently isolated bacterial species in wounds yet little is known about its pathogenic mechanisms in this setting. Here, we used a mouse wound excisional model to characterize the infection dynamics of E faecalis and show that infected wounds result in 2 different states depending on the initial inoculum. Low-dose inocula were associated with short-term, low-titer colonization whereas high-dose inocula were associated with acute bacterial replication and long-term persistence. High-dose infection and persistence were also associated with immune cell infiltration, despite suppression of some inflammatory cytokines and delayed wound healing. During high-dose infection, the multiple peptide resistance factor, which is involved in resisting immune clearance, contributes to E faecalis fitness. These results comprehensively describe a mouse model for investigating E faecalis wound infection determinants, and suggest that both immune modulation and resistance contribute to persistent, nonhealing wounds.
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Affiliation(s)
- Kelvin Kian Long Chong
- Singapore Centre for Environmental Life Sciences Engineering, Singapore.,Nanyang Technological University Institute for Health Technologies, Singapore
| | - Wei Hong Tay
- Singapore Centre for Environmental Life Sciences Engineering, Singapore.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
| | - Baptiste Janela
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | - Adeline Mei Hui Yong
- Singapore Centre for Environmental Life Sciences Engineering, Singapore.,School of Biological Sciences, Singapore
| | - Tze Horng Liew
- Singapore Centre for Environmental Life Sciences Engineering, Singapore
| | - Leigh Madden
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Damien Keogh
- Singapore Centre for Environmental Life Sciences Engineering, Singapore
| | | | - Florent Ginhoux
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
| | | | - Kimberly A Kline
- Singapore Centre for Environmental Life Sciences Engineering, Singapore.,Singapore Immunology Network, Agency for Science, Technology and Research, Singapore
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Abstract
Multidrug-resistant A. baumannii are important Gram-negative pathogens causing persistent wound infections in both wounded and burned victims, which often result in secondary complications such as delayed wound healing, skin graft failure, and sometimes more serious outcomes such as sepsis and amputation. The choice of antibiotics to remediate these A. baumannii infections is becoming limited; and therefore, there has been a renewed interest in the research and development of new antibacterials targeting this pathogen. However, the evaluation of safety and efficacy is made more difficult by the lack of well-established in vivo models. This chapter describes established rodent and large animal models that have been used to investigate and develop treatments for A. baumannii skin and soft tissue infections.
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Zurawski DV, Black CC, Alamneh YA, Biggemann L, Banerjee J, Thompson MG, Wise MC, Honnold CL, Kim RK, Paranavitana C, Shearer JP, Tyner SD, Demons ST. A Porcine Wound Model of Acinetobacter baumannii Infection. Adv Wound Care (New Rochelle) 2019; 8:14-27. [PMID: 30705786 PMCID: PMC6350066 DOI: 10.1089/wound.2018.0786] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/24/2018] [Indexed: 01/25/2023] Open
Abstract
Objective: To better understand Acinetobacter baumannii pathogenesis and to advance drug discovery against this pathogen, we developed a porcine, full-thickness, excisional, monospecies infection wound model. Approach: The research was facilitated with AB5075, a previously characterized, extensively drug-resistant A. baumannii isolate. The model requires cyclophosphamide-induced neutropenia to establish a skin and soft tissue infection (SSTI) that persists beyond 7 days. Multiple, 12-mm-diameter full-thickness wounds were created in the skin overlying the cervical and thoracic dorsum. Wound beds were inoculated with 5.0 × 104 colony-forming units (CFU) and covered with dressing. Results:A. baumannii was observed in the wound bed and on the dressing in what appeared to be biofilm. When bacterial burdens were measured, proliferation to at least 106 CFU/g (log106) wound tissue was observed. Infection was further characterized by scanning electron microscopy (SEM) and peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) staining. To validate as a treatment model, polymyxin B was applied topically to a subset of infected wounds every 2 days. Then, the treated and untreated wounds were compared using multiple quantitative and qualitative techniques to include gross pathology, CFU burden, histopathology, PNA-FISH, and SEM. Innovation: This is the first study to use A. baumannii in a porcine model as the sole infectious agent. Conclusion: The porcine model allows for an additional preclinical assessment of antibacterial candidates that show promise against A. baumannii in rodent models, further evaluating safety and efficacy, and serve as a large animal in preclinical assessment for the treatment of SSTI.
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Affiliation(s)
- Daniel V. Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Chad C. Black
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Yonas A. Alamneh
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Lionel Biggemann
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Jaideep Banerjee
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Mitchell G. Thompson
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Matthew C. Wise
- Veterinary Services Program, Department of Pathology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Cary L. Honnold
- Veterinary Services Program, Department of Pathology, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Robert K. Kim
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Chrysanthi Paranavitana
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Jonathan P. Shearer
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Stuart D. Tyner
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Samandra T. Demons
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
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Rishi P, Vashist T, Sharma A, Kaur A, Kaur A, Kaur N, Kaur IP, Tewari R. Efficacy of designer K11 antimicrobial peptide (a hybrid of melittin, cecropin A1 and magainin 2) against Acinetobacter baumannii-infected wounds. Pathog Dis 2018; 76:5089976. [DOI: 10.1093/femspd/fty072] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 09/01/2018] [Indexed: 12/31/2022] Open
Affiliation(s)
- Praveen Rishi
- Department of Microbiology, Basic Medical Sciences Block I, South Campus, Sector 25, Panjab University, Chandigarh-160014, India
| | - Tanvi Vashist
- Department of Microbiology, Basic Medical Sciences Block I, South Campus, Sector 25, Panjab University, Chandigarh-160014, India
| | - Avantika Sharma
- Department of Microbial Biotechnology, South Campus, Sector 25, Panjab University, Chandigarh-160014, India
| | - Amrita Kaur
- Department of Microbiology, Basic Medical Sciences Block I, South Campus, Sector 25, Panjab University, Chandigarh-160014, India
| | - Arashdeep Kaur
- Department of Microbiology, Basic Medical Sciences Block I, South Campus, Sector 25, Panjab University, Chandigarh-160014, India
| | - Navneet Kaur
- Department of Microbiology, Basic Medical Sciences Block I, South Campus, Sector 25, Panjab University, Chandigarh-160014, India
- CSIR-Institute of Microbial Technology, Sector-39 A, Chandigarh-160036, India
| | - Indu Pal Kaur
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh-160014, India
| | - Rupinder Tewari
- Department of Microbial Biotechnology, South Campus, Sector 25, Panjab University, Chandigarh-160014, India
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Magana M, Sereti C, Ioannidis A, Mitchell CA, Ball AR, Magiorkinis E, Chatzipanagiotou S, Hamblin MR, Hadjifrangiskou M, Tegos GP. Options and Limitations in Clinical Investigation of Bacterial Biofilms. Clin Microbiol Rev 2018; 31:e00084-16. [PMID: 29618576 PMCID: PMC6056845 DOI: 10.1128/cmr.00084-16] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacteria can form single- and multispecies biofilms exhibiting diverse features based upon the microbial composition of their community and microenvironment. The study of bacterial biofilm development has received great interest in the past 20 years and is motivated by the elegant complexity characteristic of these multicellular communities and their role in infectious diseases. Biofilms can thrive on virtually any surface and can be beneficial or detrimental based upon the community's interplay and the surface. Advances in the understanding of structural and functional variations and the roles that biofilms play in disease and host-pathogen interactions have been addressed through comprehensive literature searches. In this review article, a synopsis of the methodological landscape of biofilm analysis is provided, including an evaluation of the current trends in methodological research. We deem this worthwhile because a keyword-oriented bibliographical search reveals that less than 5% of the biofilm literature is devoted to methodology. In this report, we (i) summarize current methodologies for biofilm characterization, monitoring, and quantification; (ii) discuss advances in the discovery of effective imaging and sensing tools and modalities; (iii) provide an overview of tailored animal models that assess features of biofilm infections; and (iv) make recommendations defining the most appropriate methodological tools for clinical settings.
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Affiliation(s)
- Maria Magana
- Department of Clinical Microbiology, Athens Medical School, Aeginition Hospital, Athens, Greece
| | - Christina Sereti
- Department of Clinical Microbiology, Athens Medical School, Aeginition Hospital, Athens, Greece
- Department of Microbiology, Thriassio General Hospital, Attiki, Greece
| | - Anastasios Ioannidis
- Department of Clinical Microbiology, Athens Medical School, Aeginition Hospital, Athens, Greece
- Department of Nursing, Faculty of Human Movement and Quality of Life Sciences, University of Peloponnese, Sparta, Greece
| | - Courtney A Mitchell
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Anthony R Ball
- Gliese 623b, Mendon, Massachusetts, USA
- GAMA Therapeutics LLC, Pepperell, Massachusetts, USA
| | - Emmanouil Magiorkinis
- Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens-Goudi, Greece
| | | | - Michael R Hamblin
- Harvard-MIT Division of Health Science and Technology, Cambridge, Massachusetts, USA
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Maria Hadjifrangiskou
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - George P Tegos
- Gliese 623b, Mendon, Massachusetts, USA
- GAMA Therapeutics LLC, Pepperell, Massachusetts, USA
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38
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Bahador A, Farshadzadeh Z, Raoofian R, Mokhtaran M, Pourakbari B, Pourhajibagher M, Hashemi FB. Association of virulence gene expression with colistin-resistance in Acinetobacter baumannii: analysis of genotype, antimicrobial susceptibility, and biofilm formation. Ann Clin Microbiol Antimicrob 2018; 17:24. [PMID: 29859115 PMCID: PMC5984448 DOI: 10.1186/s12941-018-0277-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/19/2018] [Indexed: 12/01/2022] Open
Abstract
Background Acinetobacter baumannii causes difficult-to-treat nosocomial infections, which often lead to morbidity due to the development of antimicrobial drug resistance and expression of virulence genes. Data regarding the association of resistance to colistin, a last treatment option, and the virulence gene expression of A. baumannii is scarce. Methods We evaluated the MLVA genotype, antimicrobial resistance, and biofilm formation of 100 A. baumannii isolates from burn patients, and further compared the in vitro and in vivo expression of four virulence genes among five colistin-resistant A. baumannii (Cst-R-AB) isolates. Five Cst-R-AB isolates were tested; one from the present study, and four isolated previously. Results Our results showed that reduced expression of recA, along with increased in vivo expression of lpsB, dnaK, and blsA; are associated with colistin resistance among Cst-R-AB isolates. Differences in virulence gene expressions among Cst-R-AB isolates, may in part explain common discrepant in vitro vs. in vivo susceptibility data during treatment of infections caused by Cst-R-AB. Conclusions Our findings highlight the intricate relationship between colistin-resistance and virulence among A. baumannii isolates, and underscore the importance of examining the interactions between virulence and antimicrobial resistance toward efforts to control the spread of multidrug-resistant A. baumannii (MDR-AB) isolates, and also to reduce disease severity in burn patients with MDR-AB infection. Electronic supplementary material The online version of this article (10.1186/s12941-018-0277-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Abbas Bahador
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, 100 Poursina Ave., 100 Keshavarz Blvd, Tehran, 14167-53955, Iran.,Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.,Laser Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Farshadzadeh
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, 100 Poursina Ave., 100 Keshavarz Blvd, Tehran, 14167-53955, Iran
| | - Reza Raoofian
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran.,Innovative Research Center, Islamic Azad University, Mashhad Branch, Mashhad, Iran
| | - Masoumeh Mokhtaran
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, 100 Poursina Ave., 100 Keshavarz Blvd, Tehran, 14167-53955, Iran
| | - Babak Pourakbari
- Pediatrics Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Pourhajibagher
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, 100 Poursina Ave., 100 Keshavarz Blvd, Tehran, 14167-53955, Iran.,Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Farhad B Hashemi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, 100 Poursina Ave., 100 Keshavarz Blvd, Tehran, 14167-53955, Iran.
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Harding CM, Hennon SW, Feldman MF. Uncovering the mechanisms of Acinetobacter baumannii virulence. Nat Rev Microbiol 2017; 16:91-102. [PMID: 29249812 DOI: 10.1038/nrmicro.2017.148] [Citation(s) in RCA: 542] [Impact Index Per Article: 77.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Acinetobacter baumannii is a nosocomial pathogen that causes ventilator-associated as well as bloodstream infections in critically ill patients, and the spread of multidrug-resistant Acinetobacter strains is cause for concern. Much of the success of A. baumannii can be directly attributed to its plastic genome, which rapidly mutates when faced with adversity and stress. However, fundamental virulence mechanisms beyond canonical drug resistance were recently uncovered that enable A. baumannii and, to a limited extent, other medically relevant Acinetobacter species to successfully thrive in the health-care environment. In this Review, we explore the molecular features that promote environmental persistence, including desiccation resistance, biofilm formation and motility, and we discuss the most recently identified virulence factors, such as secretion systems, surface glycoconjugates and micronutrient acquisition systems that collectively enable these pathogens to successfully infect their hosts.
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Affiliation(s)
- Christian M Harding
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA.,VaxNewMo LLC, St. Louis, Missouri 63108, USA
| | - Seth W Hennon
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Mario F Feldman
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA.,VaxNewMo LLC, St. Louis, Missouri 63108, USA
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Clinical and Pathophysiological Overview of Acinetobacter Infections: a Century of Challenges. Clin Microbiol Rev 2017; 30:409-447. [PMID: 27974412 DOI: 10.1128/cmr.00058-16] [Citation(s) in RCA: 616] [Impact Index Per Article: 88.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Acinetobacter is a complex genus, and historically, there has been confusion about the existence of multiple species. The species commonly cause nosocomial infections, predominantly aspiration pneumonia and catheter-associated bacteremia, but can also cause soft tissue and urinary tract infections. Community-acquired infections by Acinetobacter spp. are increasingly reported. Transmission of Acinetobacter and subsequent disease is facilitated by the organism's environmental tenacity, resistance to desiccation, and evasion of host immunity. The virulence properties demonstrated by Acinetobacter spp. primarily stem from evasion of rapid clearance by the innate immune system, effectively enabling high bacterial density that triggers lipopolysaccharide (LPS)-Toll-like receptor 4 (TLR4)-mediated sepsis. Capsular polysaccharide is a critical virulence factor that enables immune evasion, while LPS triggers septic shock. However, the primary driver of clinical outcome is antibiotic resistance. Administration of initially effective therapy is key to improving survival, reducing 30-day mortality threefold. Regrettably, due to the high frequency of this organism having an extreme drug resistance (XDR) phenotype, early initiation of effective therapy is a major clinical challenge. Given its high rate of antibiotic resistance and abysmal outcomes (up to 70% mortality rate from infections caused by XDR strains in some case series), new preventative and therapeutic options for Acinetobacter spp. are desperately needed.
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41
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Copper Resistance of the Emerging Pathogen Acinetobacter baumannii. Appl Environ Microbiol 2016; 82:6174-6188. [PMID: 27520808 DOI: 10.1128/aem.01813-16] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/04/2016] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is an important emerging pathogen that is capable of causing many types of severe infection, especially in immunocompromised hosts. Since A. baumannii can rapidly acquire antibiotic resistance genes, many infections are on the verge of being untreatable, and novel therapies are desperately needed. To investigate the potential utility of copper-based antibacterial strategies against Acinetobacter infections, we characterized copper resistance in a panel of recent clinical A. baumannii isolates. Exposure to increasing concentrations of copper in liquid culture and on solid surfaces resulted in dose-dependent and strain-dependent effects; levels of copper resistance varied broadly across isolates, possibly resulting from identified genotypic variation among strains. Examination of the growth-phase-dependent effect of copper on A. baumannii revealed that resistance to copper increased dramatically in stationary phase. Moreover, A. baumannii biofilms were more resistant to copper than planktonic cells but were still susceptible to copper toxicity. Exposure of bacteria to subinhibitory concentrations of copper allowed them to better adapt to and grow in high concentrations of copper; this copper tolerance response is likely achieved via increased expression of copper resistance mechanisms. Indeed, genomic analysis revealed numerous putative copper resistance proteins that share amino acid homology to known proteins in Escherichia coli and Pseudomonas aeruginosa Transcriptional analysis revealed significant upregulation of these putative copper resistance genes following brief copper exposure. Future characterization of copper resistance mechanisms may aid in the search for novel antibiotics against Acinetobacter and other highly antibiotic-resistant pathogens. IMPORTANCE Acinetobacter baumannii causes many types of severe nosocomial infections; unfortunately, some isolates have acquired resistance to almost every available antibiotic, and treatment options are incredibly limited. Copper is an essential nutrient but becomes toxic at high concentrations. The inherent antimicrobial properties of copper give it potential for use in novel therapeutics against drug-resistant pathogens. We show that A. baumannii clinical isolates are sensitive to copper in vitro, both in liquid and on solid metal surfaces. Since bacterial resistance to copper is mediated though mechanisms of efflux and detoxification, we identified genes encoding putative copper-related proteins in A. baumannii and showed that expression of some of these genes is regulated by the copper concentration. We propose that the antimicrobial effects of copper may be beneficial in the development of future therapeutics that target multidrug-resistant bacteria.
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Personalized Therapeutic Cocktail of Wild Environmental Phages Rescues Mice from Acinetobacter baumannii Wound Infections. Antimicrob Agents Chemother 2016; 60:5806-16. [PMID: 27431214 DOI: 10.1128/aac.02877-15] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 07/06/2016] [Indexed: 02/08/2023] Open
Abstract
Multidrug-resistant bacterial pathogens are an increasing threat to public health, and lytic bacteriophages have reemerged as a potential therapeutic option. In this work, we isolated and assembled a five-member cocktail of wild phages against Acinetobacter baumannii and demonstrated therapeutic efficacy in a mouse full-thickness dorsal infected wound model. The cocktail lowers the bioburden in the wound, prevents the spread of infection and necrosis to surrounding tissue, and decreases infection-associated morbidity. Interestingly, this effective cocktail is composed of four phages that do not kill the parent strain of the infection and one phage that simply delays bacterial growth in vitro via a strong but incomplete selection event. The cocktail here appears to function in a combinatorial manner, as one constituent phage targets capsulated A. baumannii bacteria and selects for loss of receptor, shifting the population to an uncapsulated state that is then sensitized to the remaining four phages in the cocktail. Additionally, capsule is a known virulence factor for A. baumannii, and we demonstrated that the emergent uncapsulated bacteria are avirulent in a Galleria mellonella model. These results highlight the importance of anticipating population changes during phage therapy and designing intelligent cocktails to control emergent strains, as well as the benefits of using phages that target virulence factors. Because of the efficacy of this cocktail isolated from a limited environmental pool, we have established a pipeline for developing new phage therapeutics against additional clinically relevant multidrug-resistant pathogens by using environmental phages sourced from around the globe.
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Karumathil DP, Surendran-Nair M, Venkitanarayanan K. Efficacy of Trans-cinnamaldehyde and Eugenol in Reducing Acinetobacter baumannii Adhesion to and Invasion of Human Keratinocytes and Controlling Wound Infection In Vitro. Phytother Res 2016; 30:2053-2059. [PMID: 27619325 DOI: 10.1002/ptr.5713] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/28/2016] [Accepted: 08/17/2016] [Indexed: 01/31/2023]
Abstract
The study investigated the efficacy of two natural, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC), and eugenol (EG) for decreasing Acinetobacter baumannii adhesion to and invasion of human keratinocytes (HEK001). Moreover, the efficacy of two PDAs for inhibiting A. baumannii biofilm formation was determined using an in vitro collagen matrix wound model. Additionally, the effect of TC and EG on A. baumannii biofilm architecture was visualized using confocal scanning microscopy. Further the effect of both PDAs on genes critical for biofilm synthesis was determined using real-time quantitative polymerase chain reaction. Both TC and EG significantly reduced A. baumannii adhesion and invasion to HEK001 by ~2 to 3 log10 CFU/mL (p < 0.05) compared with the controls (p < 0.05). Further, after 24 and 48 h, TC and EG inhibited biofilm formation by ~1.5 to 2 and ~2 to 3.5 log10 CFU/mL, compared with controls (p < 0.05). Confocal microscopy revealed that TC and EG disrupted the biofilm architecture. RT-qPCR results indicated that two phytochemicals significantly down-regulated the transcription of genes associated with A. baumannii biofilm production. The results suggest that both TC and EG could potentially be used to treat A. baumannii wound infections; however, their efficacy in in vivo models needs to be validated. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Deepti P Karumathil
- Department of Animal Science, University of Connecticut, Storrs, CT, 06269, USA
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Wang Y, Zhang X, Feng X, Liu X, Deng L, Liang ZA. Expression of Toll-like receptor 4 in lungs of immune-suppressed rat with Acinetobacter baumannii infection. Exp Ther Med 2016; 12:2599-2605. [PMID: 27703512 PMCID: PMC5038893 DOI: 10.3892/etm.2016.3624] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 08/18/2016] [Indexed: 02/05/2023] Open
Abstract
Toll-like receptor 4 (TLR4) is involved in the regulation of host responses to Acinetobacter baumannii (A. baumannii). The aim of the present study was to examine the function of TLR4 in lung inflammation in immune-suppressed rats with A. baumannii infection. A total of 72 Sprague-Dawley male rats were randomly divided into the control, A. baumannii infection and immune-suppressed infection groups. The immune-suppressed infection group was treated with 100 mg/kg hydrocortisone by subcutaneous injection every other day for 2 weeks prior to A. baumannii infection. Lung tissue was obtained on the 3rd and 7th day after tracheal inoculation with A. baumannii. The expression of TLR4 in bronchial and alveolar epithelial cells, and alveolar macrophage was examined using immunohistochemistry. The levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α in bronchoalveolar lavage fluid were detected using ELISA. The results showed that in the control group, the expression of TLR4 was upregulated in the bronchial and alveolar epithelial, and alveolar macrophages, and the levels of IL-6 and TNF-α were increased in the early phase of A. baumannii infection. On the 7th day, no significant difference in the levels of IL-6 and TNF-α was observed between the A. baumannii infection and control groups. Conversely, the expression of TLR4 was downregulated in the immune-suppressed group, and the levels of IL-6 and TNF-α were reduced on the 3rd day after infection. In the subsequent observation period, the expression of TLR4 was upregulated and the levels of IL-6 and TNF-α were increased. In conclusion, the results show a critical role of TLR4 in mediating effective immune response in the lung of rat with A. baumannii infection.
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Affiliation(s)
- Yanmei Wang
- Department of Intensive Care Unit, Sichuan Second Hospital of Traditional Chinese Medicine, Chengdu, Sichuan 610031, P.R. China
| | - Xiaohong Zhang
- Department of Emergency Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Province People's Hospital, Chengdu, Sichuan 610072, P.R. China
| | - Xuanlin Feng
- Department of Emergency Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Province People's Hospital, Chengdu, Sichuan 610072, P.R. China
| | - Xiaoshu Liu
- Department of Emergency Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Province People's Hospital, Chengdu, Sichuan 610072, P.R. China
| | - Lei Deng
- Department of Emergency Intensive Care Unit, Sichuan Academy of Medical Sciences and Sichuan Province People's Hospital, Chengdu, Sichuan 610072, P.R. China
| | - Zong-An Liang
- Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
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Hobson DW, Schuh JCL, Zurawski DV, Wang J, Arbabi S, McVean M, Funk KA. The First Cut Is the Deepest: The History and Development of Safe Treatments for Wound Healing and Tissue Repair. Int J Toxicol 2016; 35:491-8. [PMID: 27402775 DOI: 10.1177/1091581816656804] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
As the skin is the primary barrier to infection, the importance of wound healing has been understood since ancient times. This article provides a synopsis on the symposium presentations focusing on how wounds were traditionally treated, what models and pathology endpoints exist to study wound healing, special considerations for wound healing studies, an overview of regulatory aspects of new pharmaceutical and medical device development, and the clinical relevance of such models. The clinical treatment of small and large wounds is also considered.
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Affiliation(s)
| | | | - Daniel V Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Jianyong Wang
- Division of Dermatology and Dental Products (DDDP), OND/CDER/FDA, Silver Spring, MD, USA
| | - Sam Arbabi
- University of Washington, Seattle, WA, USA
| | - Maralee McVean
- PreClinical Research Services, Inc, Fort Collins, CO, USA
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Protective Effect of a Synbiotic against Multidrug-Resistant Acinetobacter baumannii in a Murine Infection Model. Antimicrob Agents Chemother 2016; 60:3041-50. [PMID: 26953197 DOI: 10.1128/aac.02928-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/02/2016] [Indexed: 12/17/2022] Open
Abstract
This study investigated the ability of the probiotic Bifidobacterium breve strain Yakult (BbY) to protect against infection, as well as the potentiation of BbY activity by the synbiotic combination of BbY and prebiotic galactooligosaccharides (GOS). The study employed a mouse model of lethal intestinal multidrug-resistant Acinetobacter baumannii (MDRAb) infection. The endogenous intestinal microbiota was disrupted by the administration of multiple antibiotics, causing the loss of endogenous Bifidobacterium Oral infection of these mice with MDRAb resulted in marked growth of this organism. Additional treatment of the infected mice with a sublethal dose of 5-fluorouracil (5-FU) induced systemic invasion by MDRAb and subsequent animal death. The continuous oral administration of BbY increased the survival rate and inhibited the intestinal growth and invasion by MDRAb in the infection model. Disruptions of the intestinal environment and barrier function in the infected mice were attenuated by BbY. Protection against the MDRAb infection was markedly potentiated by a synbiotic combination of BbY and GOS, although GOS by itself did not provide protection. Negative correlations were observed between intestinal MDRAb and BbY counts or acetic acid levels; positive correlations were observed between acetic acid levels and intestinal epithelium expression of tight-junction-related genes. These results demonstrated that the probiotic and synbiotic markedly potentiated protection against fatal intestinal infection caused by a multidrug-resistant bacterium. Probiotics and synbiotics are presumed to provide protection by compensation for the disrupted indigenous populations, thereby maintaining the intestinal environments and barrier functions otherwise targeted during opportunistic infection by MDRAb.
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Wang Y, Wu X, Chen J, Amin R, Lu M, Bhayana B, Zhao J, Murray CK, Hamblin MR, Hooper DC, Dai T. Antimicrobial Blue Light Inactivation of Gram-Negative Pathogens in Biofilms: In Vitro and In Vivo Studies. J Infect Dis 2016; 213:1380-7. [PMID: 26908743 DOI: 10.1093/infdis/jiw070] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 02/01/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Biofilms affect >80% bacterial infections in human and are usually difficult to eradicate because of their inherent drug resistance. METHODS We investigated the effectiveness of antimicrobial blue light (aBL) (wavelength, 415 nm) for inactivating Acinetobacter baumannii or Pseudomonas aeruginosa biofilms in 96-well microplates or infected mouse burn wounds. RESULTS In vitro, in 96-well microplates, exposure of 24-hour-old and 72-hour-old A. baumannii biofilms to 432 J/cm(2) aBL resulted in inactivation of 3.59 log10 and 3.18 log10 colony-forming units (CFU), respectively. For P. aeruginosa biofilms, similar levels of inactivation-3.02 log10 and 3.12 log10 CFU, respectively-were achieved. In mouse burn wounds infected with 5 × 10(6) CFU ofA. baumannii, approximately 360 J/cm(2) and 540 J/cm(2) aBL was required to inactivate 3 log10 CFU in biofilms when delivered 24 and 48 hours, respectively, after bacterial inoculation. High-performance liquid chromatography analysis revealed the presence of endogenous porphyrins in both A. baumannii and P. aeruginosa TUNEL assay detected no apoptotic cells in aBL-irradiated mouse skin at up to 24 hours after aBL exposure (540 J/cm(2)). CONCLUSIONS aBL has antimicrobial activity in biofilms ofA. baumannii and P. aeruginosa and is a potential therapeutic approach for biofilm-related infections.
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Affiliation(s)
- Yucheng Wang
- Department of Laser Medicine, Chinese PLA General Hospital, Beijing College of Medicine, Nankai University, Tianjin Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Ximing Wu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Jia Chen
- Shanghai Dermatology Hospital, China Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Rehab Amin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Min Lu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Brijesh Bhayana
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Jie Zhao
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Clinton K Murray
- Infectious Disease Service, Brooke Army Medical Center, Fort Sam Houston, Texas
| | - Michael R Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts
| | - David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
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Grguric-Smith LM, Lee HH, Gandhi JA, Brennan MB, DeLeon-Rodriguez CM, Coelho C, Han G, Martinez LR. Neutropenia exacerbates infection by Acinetobacter baumannii clinical isolates in a murine wound model. Front Microbiol 2015; 6:1134. [PMID: 26528277 PMCID: PMC4607880 DOI: 10.3389/fmicb.2015.01134] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 10/02/2015] [Indexed: 01/21/2023] Open
Abstract
The Gram negative coccobacillus Acinetobacter baumannii has become an increasingly prevalent cause of hospital-acquired infections in recent years. The majority of clinical A. baumannii isolates display high-level resistance to antimicrobials, which severely compromises our capacity to care for patients with A. baumannii disease. Neutrophils are of major importance in the host defense against microbial infections. However, the contribution of these cells of innate immunity in host resistance to cutaneous A. baumannii infection has not been directly investigated. Hence, we hypothesized that depletion of neutrophils increases severity of bacterial disease in an experimental A. baumannii murine wound model. In this study, the Ly-6G-specific monoclonal antibody (mAb), 1A8, was used to generate neutropenic mice and the pathogenesis of several A. baumannii clinical isolates on wounded cutaneous tissue was investigated. We demonstrated that neutrophil depletion enhances bacterial burden using colony forming unit determinations. Also, mAb 1A8 reduces global measurements of wound healing in A. baumannii-infected animals. Interestingly, histological analysis of cutaneous tissue excised from A. baumannii-infected animals treated with mAb 1A8 displays enhanced collagen deposition. Furthermore, neutropenia and A. baumannii infection alter pro-inflammatory cytokine release leading to severe microbial disease. Our findings provide a better understanding of the impact of these innate immune cells in controlling A. baumannii skin infections.
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Affiliation(s)
| | - Hiu H Lee
- Department of Biomedical Sciences, Long Island University-Post Brookville, NY, USA ; Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology Old Westbury, NY, USA
| | - Jay A Gandhi
- Department of Biomedical Sciences, Long Island University-Post Brookville, NY, USA
| | - Melissa B Brennan
- Department of Biomedical Sciences, Long Island University-Post Brookville, NY, USA
| | | | - Carolina Coelho
- Centre for Molecular & Cellular Biology of Inflammation, Kings College London, UK
| | - George Han
- Montefiore Medical Center, Division of Dermatology, Department of Medicine Bronx, NY, USA
| | - Luis R Martinez
- Department of Biomedical Sciences, College of Osteopathic Medicine, New York Institute of Technology Old Westbury, NY, USA
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Pavey GJ, Qureshi AT, Hope DN, Pavlicek RL, Potter BK, Forsberg JA, Davis TA. Bioburden Increases Heterotopic Ossification Formation in an Established Rat Model. Clin Orthop Relat Res 2015; 473:2840-7. [PMID: 25822455 PMCID: PMC4523512 DOI: 10.1007/s11999-015-4272-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Heterotopic ossification (HO) develops in a majority of combat-related amputations wherein early bacterial colonization has been considered a potential early risk factor. Our group has recently developed a small animal model of trauma-induced HO that incorporates many of the multifaceted injury patterns of combat trauma in the absence of bacterial contamination and subsequent wound colonization. QUESTIONS/PURPOSES We sought to determine if (1) the presence of bioburden (Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus [MRSA]) increases the magnitude of ectopic bone formation in traumatized muscle after amputation; and (2) what persistent effects bacterial contamination has on late microbial flora within the amputation site. METHODS Using a blast-related HO model, we exposed 48 rats to blast overpressure, femur fracture, crush injury, and subsequent immediate transfemoral amputation through the zone of injury. Control injured rats (n = 8) were inoculated beneath the myodesis with phosphate-buffered saline not containing bacteria (vehicle) and treatment rats were inoculated with 1 × 10(6) colony-forming units of A baumannii (n = 20) or MRSA (n = 20). All animals formed HO. Heterotopic ossification was determined by quantitative volumetric measurements of ectopic bone at 12-weeks postinjury using micro-CT and qualitative histomorphometry for assessment of new bone formation in the residual limb. Bone marrow and muscle tissue biopsies were collected from the residual limb at 12 weeks to quantitatively measure the bioburden load and to qualitatively determine the species-level identification of the bacterial flora. RESULTS At 12 weeks, we observed a greater volume of HO in rats infected with MRSA (68.9 ± 8.6 mm(3); 95% confidence interval [CI], 50.52-85.55) when compared with A baumannii (20.9 ± 3.7 mm(3); 95% CI, 13.61-28.14; p < 0.001) or vehicle (16.3 ± 3.2 mm(3); 95% CI, 10.06-22.47; p < 0.001). Soft tissue and marrow from the residual limb of rats inoculated with A baumannii tested negative for A baumannii infection but were positive for other strains of bacteria (1.33 × 10(2) ± 0.89 × 10(2); 95% CI, -0.42 × 10(2)-3.08 × 10(2) and 1.25 × 10(6) ± 0.69 × 10(6); 95% CI, -0.13 × 10(6)-2.60 × 10(6) colony-forming units in bone marrow and muscle tissue, respectively), whereas tissue from MRSA-infected rats contained MRSA only (4.84 × 10(1) ± 3.22 × 10(1); 95% CI, -1.47 × 10(1)-11.1 × 10(1) and 2.80 × 10(7) ± 1.73 × 10(7); 95% CI, -0.60 × 10(7)-6.20 × 10(7) in bone marrow and muscle tissue, respectively). CONCLUSIONS Our findings demonstrate that persistent infection with MRSA results in a greater volume of ectopic bone formation, which may be the result of chronic soft tissue inflammation, and that early wound colonization may be a key risk factor. CLINICAL RELEVANCE Interventions that mitigate wound contamination and inflammation (such as early débridement, systemic and local antibiotics) may also have a beneficial effect with regard to the mitigation of HO formation and should be evaluated with that potential in mind in future preclinical studies.
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MESH Headings
- Acinetobacter baumannii/pathogenicity
- Amputation, Surgical
- Animals
- Bacterial Load
- Biopsy
- Blast Injuries/complications
- Colony Count, Microbial
- Disease Models, Animal
- Femoral Fractures/complications
- Male
- Methicillin-Resistant Staphylococcus aureus/pathogenicity
- Muscle, Skeletal/diagnostic imaging
- Muscle, Skeletal/injuries
- Muscle, Skeletal/microbiology
- Muscle, Skeletal/pathology
- Ossification, Heterotopic/diagnosis
- Ossification, Heterotopic/microbiology
- Osteogenesis
- Rats, Sprague-Dawley
- Risk Factors
- Staphylococcal Infections/diagnosis
- Staphylococcal Infections/microbiology
- Time Factors
- Wound Infection/diagnosis
- Wound Infection/microbiology
- X-Ray Microtomography
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Affiliation(s)
- Gabriel J. Pavey
- />Regenerative Medicine Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
- />Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, MD USA
| | - Ammar T. Qureshi
- />Regenerative Medicine Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
| | - Donald N. Hope
- />Regenerative Medicine Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
- />Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, MD USA
| | - Rebecca L. Pavlicek
- />Department of Wound Infections, Naval Medical Research Center, Silver Spring, MD USA
| | - Benjamin K. Potter
- />Regenerative Medicine Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
- />Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, MD USA
- />Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD USA
| | - Jonathan A. Forsberg
- />Regenerative Medicine Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
- />Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, MD USA
- />Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD USA
| | - Thomas A. Davis
- />Regenerative Medicine Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
- />Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD USA
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Evaluation of Gallium Citrate Formulations against a Multidrug-Resistant Strain of Klebsiella pneumoniae in a Murine Wound Model of Infection. Antimicrob Agents Chemother 2015; 59:6484-93. [PMID: 26239978 PMCID: PMC4576086 DOI: 10.1128/aac.00882-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/30/2015] [Indexed: 01/16/2023] Open
Abstract
Skin and soft tissue infections (SSTIs) are a common occurrence in health care facilities with a heightened risk for immunocompromised patients. Klebsiella pneumoniae has been increasingly implicated as the bacterial agent responsible for SSTIs, and treatment can be challenging as more strains become multidrug resistant (MDR). Therefore, new treatments are needed to counter this bacterial pathogen. Gallium complexes exhibit antimicrobial activity and are currently being evaluated as potential treatment for bacterial infections. In this study, we tested a topical formulation containing gallium citrate (GaCi) for the treatment of wounds infected with K. pneumoniae. First, the MIC against K. pneumoniae ranged from 0.125 to 2.0 μg/ml GaCi. After this in vitro efficacy was established, two topical formulations with GaCi (0.1% [wt/vol] and 0.3% [wt/vol]) were tested in a murine wound model of MDR K. pneumoniae infection. Gross pathology and histopathology revealed K. pneumoniae-infected wounds appeared to close faster with GaCi treatment and were accompanied by reduced inflammation compared to those of untreated controls. Similarly, quantitative indications of infection remediation, such as reduced weight loss and wound area, suggested that treatment improved outcomes compared to those of untreated controls. Bacterial burdens were measured 1 and 3 days following inoculation, and a 0.5 to 1.5 log reduction of CFU was observed. Lastly, upon scanning electron microscopy analysis, GaCi treatment appeared to prevent biofilm formation on dressings compared to those of untreated controls. These results suggest that with more preclinical testing, a topical application of GaCi may be a promising alternative treatment strategy for K. pneumoniae SSTI.
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