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Dudis RS, Wong TY, Escatte MG, Alamneh YA, Abu-Taleb R, Su W, Czintos C, Fitzgerald TA, Le Breton Y, Zurawski DV. Longitudinal temperature measurement can determine humane endpoints in BALB/c mouse models of ESKAPEE infection. Virulence 2023; 14:2186331. [PMID: 36976806 PMCID: PMC10054282 DOI: 10.1080/21505594.2023.2186331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Antimicrobial resistance (AMR) is a worldwide problem, which is driving more preclinical research to find new treatments and countermeasures for drug-resistant bacteria. However, translational models in the preclinical space have remained static for years. To improve animal use ethical considerations, we assessed novel methods to evaluate survival after lethal infection with ESKAPEE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae, and Escherichia coli) in pulmonary models of infection. Consistent with published lung infection models often used for novel antimicrobial development, BALB/c mice were immunosuppressed with cyclophosphamide and inoculated intranasally with individual ESKAPEE pathogens or sterile saline. Observations were recorded at frequent intervals to determine predictive thresholds for humane endpoint decision-making. Internal temperature was measured via implanted IPTT300 microchips, and external temperature was measured using a non-contact, infrared thermometer. Additionally, clinical scores were evaluated based on animal appearance, behaviour, hydration status, respiration, and body weight. Internal temperature differences between survivors and non-survivors were statistically significant for E. faecium, S. aureus, K. pneumoniae, A. baumannii, E. cloacae, and E. coli, and external temperature differences were statistically significant for S. aureus, K. pneumoniae, E. cloacae, and E. coli. Internal temperature more precisely predicted mortality compared to external temperature, indicating that a threshold of 85ºF (29.4ºC) was 86.0% predictive of mortality and 98.7% predictive of survival. Based on our findings, we recommend future studies involving BALB/c mice ESKAPEE pathogen infection use temperature monitoring as a humane endpoint threshold.
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Affiliation(s)
- Randal Scott Dudis
- Veterinary Services Program, Center for Enabling Capabilities, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Ting Y Wong
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Mariel G Escatte
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Yonas A Alamneh
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Rania Abu-Taleb
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Wanwen Su
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Christine Czintos
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Timothy A Fitzgerald
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Yoann Le Breton
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Daniel V Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD, USA
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Zurawski DV, Serio AW, Black C, Pybus B, Akers KS, Deck DH, Johnson S, Chattagul S, Noble SM, Raynor M, Lanteri CA. A Review of Omadacycline for Potential Utility in the Military Health System for the Treatment of Wound Infections. Mil Med 2023:usad417. [PMID: 37963013 DOI: 10.1093/milmed/usad417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 08/21/2023] [Accepted: 10/10/2023] [Indexed: 11/16/2023] Open
Abstract
INTRODUCTION Combat-related wound infections complicate the recovery of wounded military personnel, contributing to overall morbidity and mortality. Wound infections in combat settings present unique challenges because of the size and depth of the wounds, the need to administer emergency care in the field, and the need for subsequent treatment in military facilities. Given the increase in multidrug-resistant pathogens, a novel, broad-spectrum antibiotic is desired across this continuum of care when the standard of care fails. Omadacycline was FDA-approved in 2018 for treatment of adults with acute bacterial skin and skin structure infections (ABSSSI), as well as community-acquired bacterial pneumonia (CABP). It is a broad-spectrum antibiotic with activity against gram-positive, gram-negative, and atypical bacterial pathogens, including multidrug-resistant species. Omadacycline can overcome commonly reported tetracycline resistance mechanisms, ribosomal protection proteins, and efflux pumps, and is available in once-daily intravenous or oral formulations. In this review, we discuss the potential role of omadacycline, which is included in the Department of Defense Formulary, in the context of combat wound infections. MATERIALS AND METHODS A literature review was undertaken for manuscripts published before July 21, 2023. This included a series of publications found via PubMed and a bibliography made publicly available on the Paratek Pharmaceuticals, Inc. website. Publications presenting primary data published in English on omadacycline in relation to ESKAPEE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, and Enterobacter species) pathogens and Clostridioides difficile, including in vitro, in vivo, and clinical data were included. RESULTS Of 260 identified records, 66 were included for evidence review. Omadacycline has in vitro activity against almost all the ESKAPEE pathogens, apart from P. aeruginosa. Importantly, it has activity against the four most prevalent bacterial pathogens that cause wound infections in the military healthcare system: S. aureus, including methicillin-resistant S. aureus, A. baumannii, K. pneumoniae, and E. coli. In vivo studies in rats have shown that omadacycline is rapidly distributed in most tissues, with the highest tissue-to-blood concentration ratios in bone mineral. The clinical efficacy of omadacycline has been assessed in three separate Phase 3 studies in patients with ABSSSI (OASIS-1 and OASIS-2) and with CABP (OPTIC). Overall, omadacycline has an established safety profile in the treatment of both ABSSSI and CABP. CONCLUSIONS Omadacycline has broad-spectrum activity, the option to be orally administered and an established safety profile, making it a potentially attractive replacement for moxifloxacin in the military individual first aid kit, especially when accounting for the increasing resistance to fluoroquinolones. Further studies and clinical evaluation are warranted to support broader use of omadacycline to treat combat wound infections in the military healthcare system.
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Affiliation(s)
- 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
| | - Alisa W Serio
- Paratek Pharmaceuticals, King of Prussia, PA 19406, USA
| | - Chad Black
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Brandon Pybus
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Kevin S Akers
- Combat Wound Care Research Team (CRT4), U.S. Army Institute of Surgical Research, San Antonio, TX 78234, USA
| | - Daniel H Deck
- Paratek Pharmaceuticals, King of Prussia, PA 19406, USA
| | - Sheila Johnson
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Supaksorn Chattagul
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Schroeder M Noble
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Malik Raynor
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Charlotte A Lanteri
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
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Limwongyut J, Moreland AS, Zhang K, Raynor M, Chattagul S, Fitzgerald TA, Le Breton Y, Zurawski DV, Bazan GC. Amidine-Based Cationic Conjugated Oligoelectrolytes with Antimicrobial Activity against Pseudomonas aeruginosa Biofilms. J Med Chem 2023; 66:14303-14314. [PMID: 37798258 DOI: 10.1021/acs.jmedchem.3c01329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium that can cause high-morbidity infections. Due to its robust, flexible genome and ability to form biofilms, it can evade and rapidly develop resistance to antibiotics. Cationic conjugated oligoelectrolytes (COEs) have emerged as a promising class of antimicrobials. Herein, we report a series of amidine-containing COEs with high selectivity for bacteria. From this series, we identified 1b as the most active compound against P. aeruginosa (minimum inhibitory concentration (MIC) = 2 μg/mL) with low cytotoxicity (IC50 (HepG2) = 1024 μg/mL). The activity of 1b was not affected by known drug-resistant phenotypes of 100 diverse P. aeruginosa isolates. Moreover, 1b is bactericidal with a low propensity for P. aeruginosa to develop resistance. Furthermore, 1b is also able to inhibit biofilm formation at subinhibitory concentrations and kills P. aeruginosa in established biofilms. The in vivo efficacy of 1b was demonstrated in biofilm-associated murine wound infection models.
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Affiliation(s)
- Jakkarin Limwongyut
- Department of Chemistry, National University of Singapore, 117544 Singapore
- Center for Polymers and Organic Solids, Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Alex S Moreland
- Center for Polymers and Organic Solids, Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Kaixi Zhang
- Department of Chemistry, National University of Singapore, 117544 Singapore
| | - Malik Raynor
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Supaksorn Chattagul
- Experimental Therapeutics Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Timothy A Fitzgerald
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Yoann Le Breton
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Daniel V Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Guillermo C Bazan
- Department of Chemistry, National University of Singapore, 117544 Singapore
- Center for Polymers and Organic Solids, Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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Turbyfill KR, Clarkson KA, Oaks EV, Zurawski DV, Vortherms AR, Kaminski RW. Development of the Shigella flexneri 2a, 3a, 6, and S. sonnei artificial Invaplex (Invaplex AR) vaccines. mSphere 2023; 8:e0007323. [PMID: 37389412 PMCID: PMC10449495 DOI: 10.1128/msphere.00073-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/16/2023] [Indexed: 07/01/2023] Open
Abstract
The Shigella artificial invasin complex (InvaplexAR) vaccine is a subunit approach that effectively induces robust immunogenicity directed to serotype-specific lipopolysaccharide and the broadly conserved IpaB and IpaC proteins. One advantage of the vaccine approach is the ability to adjust the constituents to address suboptimal immunogenicity and to change the Shigella serotype targeted by the vaccine. As the vaccine moves through the product development pipeline, substantial modifications have been made to address manufacturing feasibility, acceptability to regulatory authorities, and developing immunogenic and effective products for an expanded list of Shigella serotypes. Modifications of the recombinant clones used to express affinity tag-free proteins using well-established purification methods, changes to detergents utilized in the assembly process, and in vitro and in vivo evaluation of different Invaplex formulations have led to the establishment of a scalable, reproducible manufacturing process and enhanced immunogenicity of Invaplex products designed to protect against four of the most predominant Shigella serotypes responsible for global morbidity and mortality. These adjustments and improvements provide the pathway for the manufacture and clinical testing of a multivalent Invaplex vaccine. IMPORTANCE Shigella species are a major global health concern that cause severe diarrhea and dysentery in children and travelers to endemic areas of the world. Despite significant advancements in access to clean water, the increases in antimicrobial resistance and the risk of post-infection sequelae, including cognitive and physical stunting in children, highlight the urgent need for an efficacious vaccine. One promising vaccine approach, artificial Invaplex, delivers key antigens recognized by the immune system during infection, which results in increased resistance to re-infection. The work presented here describes novel modifications to a previously described vaccine approach resulting in improved methods for manufacturing and regulatory approvals, expansion of the breadth of coverage to all major Shigella serotypes, and an increase in the potency of artificial Invaplex.
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Affiliation(s)
- K. Ross Turbyfill
- Department of Diarrheal Disease Research, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Kristen A. Clarkson
- Department of Diarrheal Disease Research, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Edwin V. Oaks
- Patuxent Research and Consulting Group, Gambrills, Maryland, USA
| | - Daniel V. Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Anthony R. Vortherms
- Department of Diarrheal Disease Research, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Robert W. Kaminski
- Department of Diarrheal Disease Research, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
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Dollery SJ, Zurawski DV, Bushnell RV, Tobin JK, Wiggins TJ, MacLeod DA, Tasker NJPER, Alamneh YA, Abu-Taleb R, Czintos CM, Su W, Escatte MG, Meeks HN, Daly MJ, Tobin GJ. Whole-cell vaccine candidates induce a protective response against virulent Acinetobacter baumannii. Front Immunol 2022; 13:941010. [PMID: 36238282 PMCID: PMC9553005 DOI: 10.3389/fimmu.2022.941010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 09/02/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii causes multi-system diseases in both nosocomial settings and a pre-disposed general population. The bacterium is not only desiccation-resistant but also notoriously resistant to multiple antibiotics and drugs of last resort including carbapenem, colistin, and sulbactam. The World Health Organization has categorized carbapenem-resistant A. baumannii at the top of its critical pathogen list in a bid to direct urgent countermeasure development. Several early-stage vaccines have shown a range of efficacies in healthy mice, but no vaccine candidates have advanced into clinical trials. Herein, we report our findings that both an ionizing γ-radiation-inactivated and a non-ionizing ultraviolet C-inactivated whole-cell vaccine candidate protects neutropenic mice from pulmonary challenge with virulent AB5075, a particularly pathogenic isolate. In addition, we demonstrate that a humoral response is sufficient for this protection via the passive immunization of neutropenic mice.
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Affiliation(s)
- Stephen J. Dollery
- Biological Mimetics, Inc., Frederick, MD, United States
- *Correspondence: Stephen J. Dollery,
| | - Daniel V. Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | | | - John K. Tobin
- Biological Mimetics, Inc., Frederick, MD, United States
| | | | | | | | - Yonas A. Alamneh
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Rania Abu-Taleb
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Christine M. Czintos
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Wanwen Su
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Mariel G. Escatte
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Heather N. Meeks
- Defense Threat Reduction Agency, Fort Belvoir, VA, United States
| | - Michael J. Daly
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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] [What about the content of this article? (0)] [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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Medina-Rojas M, Stribling W, Snesrud E, Garry BI, Li Y, Gann PM, Demons ST, Tyner SD, Zurawski DV, Antonic V. Comparison of Pseudomonas aeruginosa strains reveals that Exolysin A toxin plays an additive role in virulence. Pathog Dis 2020; 78:5804881. [PMID: 32167551 DOI: 10.1093/femspd/ftaa010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 02/18/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Pseudomonas aeruginosa possesses an array of virulence genes ensuring successful infection development. A two-partner secretion system Exolysin BA (ExlBA) is expressed in the PA7-like genetic outliers consisting of ExlA, a pore-forming toxin and ExlB transporter protein. Presence of exlBA in multidrug-resistant (MDR) strains has not been investigated, particularly in the strains isolated from wounded soldiers. METHODS We screened whole genome sequences of 2439 MDR- P. aeruginosa strains for the presence of exlBA. We compiled all exlBA positive strains and compared them with a diversity set for demographics, antimicrobial profiles and phenotypic characteristics: surface motility, biofilm formation, pyocyanin production and hemolysis. We compared the virulence of strains with comparable phenotypic characteristics in Galleria mellonella. RESULTS We identified 33 exlBA-positive strains (1.5%). These strains have increased antibiotic resistance, they are more motile, produce more robust biofilms and have comparable pyocianin production with the diversity set despite the phenotypic differences within the group. In in vivo infection models, these strains were less virulent than Type III Secretion System (T3SS) positive counterparts. CONCLUSIONS exlBA-positive strains are wide spread among the PA7-like outliers. While not as virulent as strains possessing T3SS, these strains exhibit phenotypic features associated with virulence and are still lethal in vivo.
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Affiliation(s)
- Maria Medina-Rojas
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - William Stribling
- Walter Reed Army Institute of Research, Multidrug-Resistant Organism Repository and Surveillance Network, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Erik Snesrud
- Walter Reed Army Institute of Research, Multidrug-Resistant Organism Repository and Surveillance Network, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Brittany I Garry
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Yuanzhang Li
- Walter Reed Army Institute of Research, Preventive Medicine, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Patrick Mc Gann
- Walter Reed Army Institute of Research, Multidrug-Resistant Organism Repository and Surveillance Network, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Samandra T Demons
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Stuart D Tyner
- Walter Reed Army Institute of Research, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Daniel V Zurawski
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Vlado Antonic
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
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10
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Dettweiler M, Marquez L, Lin M, Sweeney-Jones AM, Chhetri BK, Zurawski DV, Kubanek J, Quave CL. Pentagalloyl glucose from Schinus terebinthifolia inhibits growth of carbapenem-resistant Acinetobacter baumannii. Sci Rep 2020; 10:15340. [PMID: 32948818 PMCID: PMC7501240 DOI: 10.1038/s41598-020-72331-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/28/2020] [Indexed: 01/29/2023] Open
Abstract
The rise of antibiotic resistance has necessitated a search for new antimicrobials with potent activity against multidrug-resistant gram-negative pathogens, such as carbapenem-resistant Acinetobacter baumannii (CRAB). In this study, a library of botanical extracts generated from plants used to treat infections in traditional medicine was screened for growth inhibition of CRAB. A crude extract of Schinus terebinthifolia leaves exhibited 80% inhibition at 256 µg/mL and underwent bioassay-guided fractionation, leading to the isolation of pentagalloyl glucose (PGG), a bioactive gallotannin. PGG inhibited growth of both CRAB and susceptible A. baumannii (MIC 64-256 µg/mL), and also exhibited activity against Pseudomonas aeruginosa (MIC 16 µg/mL) and Staphylococcus aureus (MIC 64 µg/mL). A mammalian cytotoxicity assay with human keratinocytes (HaCaTs) yielded an IC50 for PGG of 256 µg/mL. Mechanistic experiments revealed iron chelation as a possible mode of action for PGG's activity against CRAB. Passaging assays for resistance did not produce any resistant mutants over a period of 21 days. In conclusion, PGG exhibits antimicrobial activity against CRAB, but due to known pharmacological restrictions in delivery, translation as a therapeutic may be limited to topical applications such as wound rinses and dressings.
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Affiliation(s)
- Micah Dettweiler
- Department of Dermatology, Emory University School of Medicine, Atlanta, GA, USA
| | - Lewis Marquez
- Molecular and Systems Pharmacology Program, Emory University, Atlanta, GA, USA
| | - Michelle Lin
- Center for the Study of Human Health, Emory University, Atlanta, GA, USA
| | - Anne M Sweeney-Jones
- School of Chemistry and Biochemistry, Center for Microbial Dynamics and Infection, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Bhuwan Khatri Chhetri
- School of Chemistry and Biochemistry, Center for Microbial Dynamics and Infection, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Daniel V Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Disease Research, Walter Reed Army Institute of Research (WRAIR), Silver Spring, Maryland, USA
| | - Julia Kubanek
- School of Chemistry and Biochemistry, Center for Microbial Dynamics and Infection, Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Cassandra L Quave
- Department of Dermatology, Emory University School of Medicine, Atlanta, GA, USA.
- Center for the Study of Human Health, Emory University, Atlanta, GA, USA.
- Emory University Herbarium, Atlanta, GA, USA.
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11
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Zurawski DV, McLendon MK. Monoclonal Antibodies as an Antibacterial Approach Against Bacterial Pathogens. Antibiotics (Basel) 2020; 9:antibiotics9040155. [PMID: 32244733 PMCID: PMC7235762 DOI: 10.3390/antibiotics9040155] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/14/2020] [Accepted: 03/16/2020] [Indexed: 12/11/2022] Open
Abstract
In the beginning of the 21st century, the frequency of antimicrobial resistance (AMR) has reached an apex, where even 4th and 5th generation antibiotics are becoming useless in clinical settings. In turn, patients are suffering from once-curable infections, with increases in morbidity and mortality. The root cause of many of these infections are the ESKAPEE pathogens (Enterococcus species, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species, and Escherichia coli), which thrive in the nosocomial environment and are the bacterial species that have seen the largest rise in the acquisition of antibiotic resistance genes. While traditional small-molecule development still dominates the antibacterial landscape for solutions to AMR, some researchers are now turning to biological approaches as potential game changers. Monoclonal antibodies (mAbs)—more specifically, human monoclonal antibodies (Hu-mAbs)—have been highly pursued in the anti-cancer, autoimmune, and antiviral fields with many success stories, but antibody development for bacterial infection is still just scratching the surface. The untapped potential for Hu-mAbs to be used as a prophylactic or therapeutic treatment for bacterial infection is exciting, as these biologics do not have the same toxicity hurdles of small molecules, could have less resistance as they often target virulence proteins rather than proteins required for survival, and are narrow spectrum (targeting just one pathogenic species), therefore avoiding the disruption of the microbiome. This mini-review will highlight the current antibacterial mAbs approved for patient use, the success stories for mAb development, and new Hu-mAb products in the antibacterial pipeline.
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12
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Williams CL, Neu HM, Alamneh YA, Reddinger RM, Jacobs AC, Singh S, Abu-Taleb R, Michel SLJ, Zurawski DV, Merrell DS. Characterization of Acinetobacter baumannii Copper Resistance Reveals a Role in Virulence. Front Microbiol 2020; 11:16. [PMID: 32117089 PMCID: PMC7015863 DOI: 10.3389/fmicb.2020.00016] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/07/2020] [Indexed: 12/30/2022] Open
Abstract
Acinetobacter baumannii is often highly drug-resistant and causes severe infections in compromised patients. These infections can be life threatening due to limited treatment options. Copper is inherently antimicrobial and increasing evidence indicates that copper containing formulations may serve as non-traditional therapeutics against multidrug-resistant bacteria. We previously reported that A. baumannii is sensitive to high concentrations of copper. To understand A. baumannii copper resistance at the molecular level, herein we identified putative copper resistance components and characterized 21 strains bearing mutations in these genes. Eight of the strains displayed a copper sensitive phenotype (pcoA, pcoB, copB, copA/cueO, copR/cusR, copS/cusS, copC, copD); the putative functions of these proteins include copper transport, oxidation, sequestration, and regulation. Importantly, many of these mutant strains still showed increased sensitivity to copper while in a biofilm. Inductively coupled plasma mass spectrometry revealed that many of these strains had defects in copper mobilization, as the mutant strains accumulated more intracellular copper than the wild-type strain. Given the crucial antimicrobial role of copper-mediated killing employed by the immune system, virulence of these mutant strains was investigated in Galleria mellonella; many of the mutant strains were attenuated. Finally, the cusR and copD strains were also investigated in the murine pneumonia model; both were found to be important for full virulence. Thus, copper possesses antimicrobial activity against multidrug-resistant A. baumannii, and copper sensitivity is further increased when copper homeostasis mechanisms are interrupted. Importantly, these proteins are crucial for full virulence of A. baumannii and may represent novel drug targets.
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Affiliation(s)
- Caitlin L Williams
- Department of Microbiology & Immunology, Uniformed Services University, Bethesda, MD, United States
| | - Heather M Neu
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Baltimore, MD, United States
| | - Yonas A Alamneh
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Ryan M Reddinger
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Anna C Jacobs
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Shweta Singh
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Rania Abu-Taleb
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Sarah L J Michel
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Baltimore, MD, United States
| | - Daniel V Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - D Scott Merrell
- Department of Microbiology & Immunology, Uniformed Services University, Bethesda, MD, United States
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13
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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14
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Kaplan JB, Mlynek KD, Hettiarachchi H, Alamneh YA, Biggemann L, Zurawski DV, Black CC, Bane CE, Kim RK, Granick MS. Extracellular polymeric substance (EPS)-degrading enzymes reduce staphylococcal surface attachment and biocide resistance on pig skin in vivo. PLoS One 2018; 13:e0205526. [PMID: 30304066 PMCID: PMC6179274 DOI: 10.1371/journal.pone.0205526] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/26/2018] [Indexed: 02/04/2023] Open
Abstract
Staphylococcal extracellular polymeric substances (EPS) such as extracellular DNA (eDNA) and poly-N-acetylglucosamine surface polysaccharide (PNAG) mediate numerous virulence traits including host colonization and antimicrobial resistance. Previous studies showed that EPS-degrading enzymes increase staphylococcal biocide susceptibility in vitro and in vivo, and decrease virulence in animal models. In the present study we tested the effect of EPS-degrading enzymes on staphylococcal skin colonization and povidone iodine susceptibility using a novel in vivo pig model that enabled us to colonize and treat 96 isolated areas of skin on a single animal in vivo. To quantitate skin colonization, punch biopsies of colonized areas were homogenized, diluted, and plated on agar for colony forming unit enumeration. Skin was colonized with either Staphylococcus epidermidis or Staphylococcus aureus. Two EPS-degrading enzymes, DNase I and the PNAG-degrading enzyme dispersin B, were employed. Enzymes were tested for their ability to inhibit skin colonization and detach preattached bacteria. The effect of enzymes on the susceptibility of preattached S. aureus to killing by povidone iodine was also measured. We found that dispersin B significantly inhibited skin colonization by S. epidermidis and detached preattached S. epidermidis cells from skin. A cocktail of dispersin B and DNase I detached preattached S. aureus cells from skin and increased their susceptibility to killing by povidone iodine. These findings suggest that staphylococcal EPS components such as eDNA and PNAG contribute to skin colonization and biocide resistance in vivo. EPS-degrading enzymes may be a useful adjunct to conventional skin antisepsis procedures in order to further reduce skin bioburden.
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Affiliation(s)
- Jeffrey B. Kaplan
- Department of Biology, American University, Washington, District of Columbia, United States of America
- * E-mail:
| | - Kevin D. Mlynek
- Department of Biology, American University, Washington, District of Columbia, United States of America
| | - Hashani Hettiarachchi
- Department of Biology, American University, Washington, District of Columbia, United States of America
| | - Yonas A. Alamneh
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Lionel Biggemann
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Daniel V. Zurawski
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Chad C. Black
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Charles E. Bane
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Robert K. Kim
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Mark S. Granick
- Department of Surgery, Rutgers New Jersey Medical School, Newark, New Jersey, United States of America
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15
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Abstract
While broad spectrum antibiotics play an invaluable role in the treatment of bacterial infections, there are some drawbacks to their use, namely selection for and spread of resistance across multiple bacterial species, and the detrimental effect they can have upon the host microbiome. If the causitive agent of the infection is known, the use of narrow-spectrum antibacterial agents has the potential to mitigate some of these issues. This review outlines the advantages and challenges of narrow-spectrum antibacterial agents, discusses the progress that has been made toward developing diagnostics to enable their use, and describes some of the narrow-spectrum antibacterial agents currently being investigated against some of the most clinically important bacteria including Clostridium difficile, Mycobacterium tuberculosis and several ESKAPE pathogens.
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Affiliation(s)
- Roberta J. Melander
- Department of Chemistry
, North Carolina State University
,
Raleigh
, NC
, USA
.
| | - Daniel V. Zurawski
- Wound Infections Department
, Bacterial Diseases Branch
, Walter Reed Army Institute of Research
,
Silver Spring
, MD
, USA
| | - Christian Melander
- Department of Chemistry
, North Carolina State University
,
Raleigh
, NC
, USA
.
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16
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Abstract
Shigella spp. causing bacterial diarrhea and dysentery are human enteroinvasive bacterial pathogens that are orally transmitted through contaminated food and water and cause bacillary dysentery. Although natural Shigella infections are restricted to humans and primates, several smaller animal models are used to analyze individual steps in pathogenesis. No animal model fully duplicates the human response and sustaining the models requires expensive animals, costly maintenance of animal facilities, veterinary services and approved animal protocols. This study proposes the development of the caterpillar larvae of Galleria mellonella as a simple, inexpensive, informative, and rapid in-vivo model for evaluating virulence and the interaction of Shigella with cells of the insect innate immunity. Virulent Shigella injected through the forelegs causes larvae death. The mortality rates were dependent on the Shigella strain, the infectious dose, and the presence of the virulence plasmid. Wild-type S. flexneri 2a, persisted and replicated within the larvae, resulting in haemocyte cell death, whereas plasmid-cured mutants were rapidly cleared. Histology of the infected larvae in conjunction with fluorescence, immunofluorescence, and transmission electron microscopy indicate that S. flexneri reside within a vacuole of the insect haemocytes that ultrastructurally resembles vacuoles described in studies with mouse and human macrophage cell lines. Some of these bacteria-laden vacuoles had double-membranes characteristic of autophagosomes. These results suggest that G. mellonella larvae can be used as an easy-to-use animal model to understand Shigella pathogenesis that requires none of the time and labor-consuming procedures typical of other systems.
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Affiliation(s)
- Shoshana Barnoy
- Department of Enteric Infections, Bacterial Diseases Branch (BDB), Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Hanan Gancz
- Wound Infections Department, BDB, Walter Reed Army Institute of Research, Silver Spring Maryland, USA
| | - Yuewei Zhu
- Department of Enteric Infections, Bacterial Diseases Branch (BDB), Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Cary L. Honnold
- Department of Pathology, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Daniel V. Zurawski
- Wound Infections Department, BDB, Walter Reed Army Institute of Research, Silver Spring Maryland, USA
| | - Malabi M. Venkatesan
- Department of Enteric Infections, Bacterial Diseases Branch (BDB), Walter Reed Army Institute of Research, Silver Spring, Maryland, USA,CONTACT Malabi M. Venkatesan Chief, Dept. of Enteric Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research (WRAIR), 503 Robert Grant Avenue, Silver Spring, MD. 20910
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17
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Corey BW, Thompson MG, Hittle LE, Jacobs AC, Asafo-Adjei EA, Huggins WM, Melander RJ, Melander C, Ernst RK, Zurawski DV. 1,2,4-Triazolidine-3-thiones Have Specific Activity against Acinetobacter baumannii among Common Nosocomial Pathogens. ACS Infect Dis 2017; 3:62-71. [PMID: 27764938 DOI: 10.1021/acsinfecdis.6b00133] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Acinetobacter baumannii are Gram-negative bacilli that pose a constant threat to susceptible patients because of increased resistance to multiple antibiotics and persistence in the hospital environment. After genome analysis, we discovered that A. baumannii harbors genes that share homology to an enzymatic pathway that elongates long-chain fatty acids (LCFA) in fungi. Previously, 1,2,4-triazolidine-3-thiones (T-3-Ts) were shown to inhibit hyphae production in fungi, and this same LCFA elongation pathway was implicated as the possible target. Therefore, we investigated if T-3-Ts also have activity against multidrug-resistant A. baumannii. Surprisingly, all of the clinical isolates of A. baumannii that were tested have susceptibility to ECC145 and ECC188 with MIC90 values of 8.0 μg/mL. In contrast, reference strains and clinical isolates of other common nosocomial bacteria that lack the LCFA pathway also lacked susceptibility. Time-kill experiments revealed that both ECC145 and ECC188 have a bacteriostatic effect against A. baumannii. Mass spectrometry analysis suggested that exposure to T-3-Ts resulted in less LCFA production. Supplementation of media with either 0.02% w/v oleic or linoleic acid abrogated the bacteriostatic effect of the compounds, which again implicated LCFA elongation as the target. Our results suggest these molecules could be a promising start to further exploit what appears to be an important aspect of A. baumannii membrane function and integrity.
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Affiliation(s)
- Brendan W. Corey
- Wound Infections Department, Bacterial
Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Mitchell G. Thompson
- Wound Infections Department, Bacterial
Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Lauren E. Hittle
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland 21201, United States
| | - Anna C. Jacobs
- Wound Infections Department, Bacterial
Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Edward A. Asafo-Adjei
- Department of Veterinary Medicine, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - William M. Huggins
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8024, United States
| | - Roberta J. Melander
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8024, United States
| | - Christian Melander
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8024, United States
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, Maryland 21201, United States
| | - Daniel V. Zurawski
- Wound Infections Department, Bacterial
Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
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18
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Huggins WM, Minrovic BM, Corey BW, Jacobs AC, Melander RJ, Sommer RD, Zurawski DV, Melander C. 1,2,4-Triazolidine-3-thiones as Narrow Spectrum Antibiotics against Multidrug-Resistant Acinetobacter baumannii. ACS Med Chem Lett 2017; 8:27-31. [PMID: 28105270 PMCID: PMC5238477 DOI: 10.1021/acsmedchemlett.6b00296] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 10/31/2016] [Indexed: 01/29/2023] Open
Abstract
![]()
With only two new classes of antibiotics
developed in the last
40 years, novel antibiotics are desperately needed to combat the growing
problem of multidrug-resistant and extensively drug resistant bacteria,
particularly Gram-negative bacteria. Described in this letter is the
synthesis and antibiotic activity of 1,2,4-triazolidine-3-thiones
as narrow spectrum antibiotics. Optimization of the 1,2,4-triazolidine-3-thione
scaffold identified a small molecule with potent antibiotic activity
against multiple strains of multidrug-resistant and extensively drug-resistant Acinetobacter baumannii. This small molecule also shows
single dose, in vivo activity in a Galleria
mellonella infection model with A. baumannii and represents a promising start in the development of a class of
drugs that can target this bacterial pathogen.
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Affiliation(s)
- William M. Huggins
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
| | - Bradley M. Minrovic
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
| | - Brendan W. Corey
- Wound
Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Anna C. Jacobs
- Wound
Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Roberta J. Melander
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
| | - Roger D. Sommer
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
| | - Daniel V. Zurawski
- Wound
Infections Department, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Christian Melander
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695, United States
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Zurawski DV, Lee RE. A Tribute to Amy Anderson (1969−2016): Leader, Role Model, and Advocate for Structure-Based Design of New Antimicrobial Agents. ACS Infect Dis 2016. [DOI: 10.1021/acsinfecdis.6b00156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel V. Zurawski
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Richard E. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Yildirim S, Thompson MG, Jacobs AC, Zurawski DV, Kirkup BC. Evaluation of Parameters for High Efficiency Transformation of Acinetobacter baumannii. Sci Rep 2016; 6:22110. [PMID: 26911658 PMCID: PMC4766488 DOI: 10.1038/srep22110] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/03/2016] [Indexed: 11/09/2022] Open
Abstract
Acinetobacter baumannii is an emerging, nosocomial pathogen that is poorly characterized due to a paucity of genetic tools and methods. While whole genome sequence data from several epidemic and environmental strains have recently become available, the functional characterization of genes is significantly lagging. Efficient transformation is one of the first steps to develop molecular tools that can be used to address these shortcomings. Here we report parameters allowing high efficiency transformation of A. baumannii. Using a multi-factorial experimental design we found that growth phase, voltage, and resistance all significantly contribute to transformation efficiency. The highest efficiency (4.3 × 10(8) Transformants/μg DNA) was obtained at the stationary growth phase of the bacterium (OD 6.0) using 25 ng of plasmid DNA under 100 Ohms resistance and 1.7 kV/cm voltage. The optimized electroporation parameters reported here provide a useful tool for genetic manipulation of A. baumannii.
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Affiliation(s)
- Suleyman Yildirim
- Department of Wound Infections, Bacterial Diseases Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Mitchell G Thompson
- Department of Wound Infections, Bacterial Diseases Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Anna C Jacobs
- Department of Wound Infections, Bacterial Diseases Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Daniel V Zurawski
- Department of Wound Infections, Bacterial Diseases Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Benjamin C Kirkup
- Department of Wound Infections, Bacterial Diseases Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.,Department of Medicine, Infectious Diseases Division, Uniformed Services University of the Health Sciences, F. Edward Hebert School of Medicine, Bethesda, Maryland, USA
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22
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Jones CL, Clancy M, Honnold C, Singh S, Snesrud E, Onmus-Leone F, McGann P, Ong AC, Kwak Y, Waterman P, Zurawski DV, Clifford RJ, Lesho E. Fatal Outbreak of an Emerging Clone of Extensively Drug-ResistantAcinetobacter baumanniiWith Enhanced Virulence. Clin Infect Dis 2015; 61:145-54. [DOI: 10.1093/cid/civ225] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 12/28/2014] [Indexed: 01/17/2023] Open
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Abstract
Acinetobacter baumannii is a Gram-negative nosocomial pathogen of clinical importance. A lack of genetic tools has hindered the research of this organism in the past; however, recently, various methods have been designed, modified, and optimized to facilitate the genetic manipulation of A. baumannii. This unit describes some of the recent genetic advances and new recombinant tools developed for this pathogen, including standard transformation and conjugation techniques specifically developed for the bacteria. As the need to understand the basic biology of A. baumannii increases with the prospect of developing new therapeutics, the use of the basic genetic methods herein can provide the critical first step to identify genes required for infection.
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Affiliation(s)
- Anna C Jacobs
- Walter Reed Army Institute of Research, Department of Wound Infections, Silver Spring, Maryland
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Jacobs AC, Zurawski DV. Laboratory Maintenance of Acinetobacter baumannii. Curr Protoc Microbiol 2014; 35:6G.1.1-6. [PMID: 25367273 DOI: 10.1002/9780471729259.mc06g01s35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Acinetobacter baumannii has recently drawn great interest in the microbiology research community due to the increase in clinical antibiotic resistance of this organism, and persistence of this bacterial species in the hospital environment. This unit outlines protocols for the growth and maintenance of A. baumannii in the laboratory.
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Affiliation(s)
- Anna C Jacobs
- Walter Reed Army Institute of Research, Department of Wound Infections, Silver Spring, Maryland
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25
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Harris TL, Worthington RJ, Hittle LE, Zurawski DV, Ernst RK, Melander C. Small molecule downregulation of PmrAB reverses lipid A modification and breaks colistin resistance. ACS Chem Biol 2014; 9:122-7. [PMID: 24131198 DOI: 10.1021/cb400490k] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Infections caused by multi-drug resistant bacteria, particularly Gram-negative bacteria, are an ever-increasing problem. While the development of new antibiotics remains one option in the fight against bacteria that have become resistant to currently available antibiotics, an attractive alternative is the development of adjuvant therapeutics that restore the efficacy of existing antibiotics. We report a small molecule adjuvant that suppresses colistin resistance in multidrug resistant Acinetobacter baumannii and Klebsiella pneumoniae by interfering with the expression of a two-component system. The compound downregulates the pmrCAB operon and reverses phosphoethanolamine modification of lipid A responsible for colistin resistance. Furthermore, colistin-susceptible and colistin-resistant bacteria do not evolve resistance to combination treatment. This represents the first definitive example of a compound that breaks antibiotic resistance by directly modulating two-component system activity.
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Affiliation(s)
- Tyler L. Harris
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Roberta J. Worthington
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Lauren E. Hittle
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, Baltimore, Maryland 21201, United States
| | - Daniel V. Zurawski
- Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, United States
| | - Robert K. Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, Baltimore, Maryland 21201, United States
| | - Christian Melander
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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26
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Clifford RJ, Milillo M, Prestwood J, Quintero R, Zurawski DV, Kwak YI, Waterman PE, Lesho EP, Mc Gann P. Detection of bacterial 16S rRNA and identification of four clinically important bacteria by real-time PCR. PLoS One 2012; 7:e48558. [PMID: 23139793 PMCID: PMC3490953 DOI: 10.1371/journal.pone.0048558] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 09/26/2012] [Indexed: 12/26/2022] Open
Abstract
Within the paradigm of clinical infectious disease research, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa represent the four most clinically relevant, and hence most extensively studied bacteria. Current culture-based methods for identifying these organisms are slow and cumbersome, and there is increasing need for more rapid and accurate molecular detection methods. Using bioinformatic tools, 962,279 bacterial 16S rRNA gene sequences were aligned, and regions of homology were selected to generate a set of real-time PCR primers that target 93.6% of all bacterial 16S rRNA sequences published to date. A set of four species-specific real-time PCR primer pairs were also designed, capable of detecting less than 100 genome copies of A. baumannii, E. coli, K. pneumoniae, and P. aeruginosa. All primers were tested for specificity in vitro against 50 species of Gram-positive and –negative bacteria. Additionally, the species-specific primers were tested against a panel of 200 clinical isolates of each species, randomly selected from a large repository of clinical isolates from diverse areas and sources. A comparison of culture and real-time PCR demonstrated 100% concordance. The primers were incorporated into a rapid assay capable of positive identification from plate or broth cultures in less than 90 minutes. Furthermore, our data demonstrate that current targets, such as the uidA gene in E.coli, are not suitable as species-specific genes due to sequence variation. The assay described herein is rapid, cost-effective and accurate, and can be easily incorporated into any research laboratory capable of real-time PCR.
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Affiliation(s)
- Robert J. Clifford
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Michael Milillo
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Jackson Prestwood
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Reyes Quintero
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Daniel V. Zurawski
- Department of Wound Infections, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Yoon I. Kwak
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Paige E. Waterman
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Emil P. Lesho
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Patrick Mc Gann
- Multi-drug Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- * E-mail:
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Kirkup BC, Craft DW, Palys T, Black C, Heitkamp R, Li C, Lu Y, Matlock N, McQueary C, Michels A, Peck G, Si Y, Summers AM, Thompson M, Zurawski DV. Traumatic wound microbiome workshop. Microb Ecol 2012; 64:837-850. [PMID: 22622764 DOI: 10.1007/s00248-012-0070-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 04/27/2012] [Indexed: 06/01/2023]
Abstract
On May 9-10, 2011, the Walter Reed Army Institute of Research, as the Army Center of Excellence for Infectious Disease, assembled over a dozen leaders in areas related to research into the communities of microorganisms which colonize and infect traumatic wounds. The objectives of the workshop were to obtain guidance for government researchers, to spur research community involvement in the field of traumatic wound research informed by a microbiome perspective, and to spark collaborative efforts serving the Wounded Warriors and similarly wounded civilians. During the discussions, it was made clear that the complexity of these infections will only be met by developing a new art of clinical practice that engages the numerous microbes and their ecology. It requires the support of dedicated laboratories and technologists who advance research methods such as community sequencing, as well as the kinds of data analysis expertise and facilities. These strategies already appear to be bearing fruit in the clinical management of chronic wounds. There are now funding announcements and programs supporting this area of research open to extramural collaborators.
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Affiliation(s)
- B C Kirkup
- Department of Wound Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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28
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Zurawski DV, Mumy KL, Faherty CS, McCormick BA, Maurelli AT. Shigella flexneri type III secretion system effectors OspB and OspF target the nucleus to downregulate the host inflammatory response via interactions with retinoblastoma protein. Mol Microbiol 2008; 71:350-68. [PMID: 19017275 DOI: 10.1111/j.1365-2958.2008.06524.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OspF, OspG and IpaH(9.8) are type III secretion system (T3SS) effectors of Shigella flexneri that downregulate the host innate immune response. OspF modifies mitogen-activated protein kinase pathways and polymorphonuclear leucocyte transepithelial migration associated with Shigella invasion. OspF also localizes in the nucleus to mediate chromatin remodelling, resulting in reduced transcription of inflammatory cytokines. We now report that OspB can be added to the set of S. flexneri T3SS effectors required to modulate the innate immune response. T84 cells infected with a Delta ospB mutant resulted in reduced polymorphonuclear leucocyte transepithelial migration and mitogen-activated protein kinase signalling. Tagged versions of OspB localized with endosomes and the nucleus. Further, T84 cells infected with the Delta ospB mutant showed increased levels of secreted IL-8 compared with wild-type infected cells. Both GST-OspB and GST-OspF coprecipitated retinoblastoma protein from host cell lysates. Because Delta ospB and Delta ospF mutants share similar phenotypes, and OspB and OspF share a host binding partner, we propose that OspB and OspF facilitate the remodelling of chromatin via interactions with retinoblastoma protein, resulting in diminished inflammatory cytokine production. The requirement of multiple T3SS effectors to modulate the innate immune response correlates to the complexity of the human immune system.
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Affiliation(s)
- Daniel V Zurawski
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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Zurawski DV, Mitsuhata C, Mumy KL, McCormick BA, Maurelli AT. OspF and OspC1 are Shigella flexneri type III secretion system effectors that are required for postinvasion aspects of virulence. Infect Immun 2006; 74:5964-76. [PMID: 16988276 PMCID: PMC1594884 DOI: 10.1128/iai.00594-06] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shigella flexneri is the causative agent of dysentery, and its pathogenesis is mediated by a type III secretion system (T3SS). S. flexneri secretes effector proteins into the eukaryotic cell via the T3SS, and these proteins usurp host cellular functions to the benefit of the bacteria. OspF and OspC1 are known to be secreted by S. flexneri, but their functions are unknown. We transformed S. flexneri with a plasmid that expresses a two-hemagglutinin tag (2HA) in frame with OspF or OspC1 and verified that these proteins are secreted in a T3SS-dependent manner. Immunofluorescence of HeLa cells infected with S. flexneri expressing OspF-2HA or OspC1-2HA revealed that both proteins localize in the nucleus and cytoplasm of host cells. To elucidate the function of these T3SS effectors, we constructed DeltaospF and DeltaospC1 deletion mutants by allelic exchange. We found that DeltaospF and DeltaospC1 mutants invade host cells and form plaques in confluent monolayers similar to wild-type S. flexneri. However, in the polymorphonuclear (PMN) cell migration assay, a decrease in neutrophil migration was observed for both mutants in comparison to the migration of wild-type bacteria. Moreover, infection of polarized T84 intestinal cells infected with DeltaospF and DeltaospC1 mutants resulted in decreased phosphorylation of extracellular signal-regulated kinase 1/2 in comparison to that of T84 cells infected with wild-type S. flexneri. To date, these are the first examples of T3SS effectors implicated in mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway activation. Ultimately, OspF and OspC1 are essential for PMN transepithelial migration, a phenotype associated with increased inflammation and bacterial access to the submucosa, which are fundamental aspects of S. flexneri pathogenesis.
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Affiliation(s)
- Daniel V Zurawski
- Department of Microbiology and Immunology, 4301 Jones Bridge Rd., Bethesda, MD 20814-4799, USA
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30
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Zurawski DV, Stein MA. The SPI2-encoded SseA chaperone has discrete domains required for SseB stabilization and export, and binds within the C-terminus of SseB and SseD. Microbiology (Reading) 2004; 150:2055-2068. [PMID: 15256549 DOI: 10.1099/mic.0.26997-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
SseA, a keySalmonellavirulence determinant, is a small, basic pI protein encoded within theSalmonellapathogenicity island 2 and serves as a type III secretion system chaperone for SseB and SseD. Both SseA partners are subunits of the surface-localized translocon module that delivers effectors into the host cell; SseB is predicted to compose the translocon sheath and SseD is a putative translocon pore subunit. In this study, SseA molecular interactions with its partners were characterized further. Yeast two-hybrid screens indicate that SseA binding requires a C-terminal domain within both partners. An additional central domain within SseD was found to influence binding. The SseA-binding region within SseB was found to encompass a predicted amphipathic helix of a type participating in coiled-coil interactions that are implicated in the assembly of translocon sheaths. Deletions that impinge upon this putative coiled-coiled domain prevent SseA binding, suggesting that SseA occupies a portion of the coiled-coil. SseA occupancy of this motif is envisioned to be sufficient to prevent premature SseB self-association inside bacteria. Domain mapping on the chaperone was also performed. A deletion of the SseA N-terminus, or site-directed mutations within this region, allowed stabilization of SseB, but its export was disrupted. Therefore, the N-terminus of SseA provides a function that is essential for SseB export, but dispensable for partner binding and stabilization.
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Affiliation(s)
- Daniel V Zurawski
- Department of Microbiology and Molecular Genetics and the Department of Animal Sciences, Markey Center for Molecular Genetics, University of Vermont, 95 Carrigan Drive, Room 118, Stafford Hall, Burlington, VT 05405, USA
| | - Murry A Stein
- Department of Microbiology and Molecular Genetics and the Department of Animal Sciences, Markey Center for Molecular Genetics, University of Vermont, 95 Carrigan Drive, Room 118, Stafford Hall, Burlington, VT 05405, USA
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Suvarnapunya AE, Zurawski DV, Guy RL, Stein MA. Molecular characterization of the prototrophic Salmonella mutants defective for intraepithelial replication. Infect Immun 2003; 71:2247-52. [PMID: 12654850 PMCID: PMC152099 DOI: 10.1128/iai.71.4.2247-2252.2003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Three MudJ prototrophs demonstrated that intracellular replication is a Salmonella virulence trait (K. Y. Leung and B. B. Finlay, Proc. Natl. Acad. Sci. USA, 88:11470-11474, 1991). mutS and mutH are disrupted in mutants 3-11 and 12-23, and ssaQ is disrupted in mutant 17-21. Further analysis revealed that loss of Salmonella pathogenicity island 2 function underlies the intracellular replication defect of 3-11 and 17-21.
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Affiliation(s)
- Akamol E Suvarnapunya
- Department of Microbiology & Molecular Genetics, University of Vermont, 95 Carrigan Drive, Burlington, VT 05405, USA
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Abstract
The Salmonella Pathogenicity Island 2 (SPI2) encodes a type III secretion system (TTSS) shown to be critical for adaptation to the intracellular environment within both phagocytic and epithelial cell types. Within SPI2, the Effector region encodes several exported proteins that comprise the SPI2 translocon (SseB, C, D). SseA is the first protein encoded within the Effector region but remains an unclassified factor that is essential for SPI2 function. In the present study, we determined that SseA shares several features with TTSS chaperones: it is small (12.5 kDa), located directly upstream of a TTSS export target (SseB), and contains an amphipathic, C-terminal alpha-helix. Construction and analysis of a DeltasseA mutant demonstrated that the total amount of SseB is significantly reduced and SPI2 export of SseB to the bacterial surface is prevented. SseB accumulation and export were restored when SseA was provided in trans. Loss of SseA does not cause a generalized defect in SPI2 secretory function as export of SseC, encoded downstream of SseB, still occurs in the DeltasseA strain. Quantitative PCR indicates that the loss of SseB in DeltasseA does not occur at the transcriptional level. Co-purification studies demonstrate that SseA directly binds to SseB. Collectively, these results demonstrate that SseA functions as a TTSS chaperone for the SPI2 translocon component, SseB.
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Affiliation(s)
- Daniel V Zurawski
- University of Vermont, Department of Microbiology and Molecular Genetics and the Markey Center for Molecular Genetics, Room 118, Stafford Hall, 95 Carrigan Dr, Burlington, VT 05405-0084, USA
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Malish HR, Freeman NL, Zurawski DV, Chowrashi P, Ayoob JC, Sanger JW, Sanger JM. Potential role of the EPEC translocated intimin receptor (Tir) in host apoptotic events. Apoptosis 2003; 8:179-90. [PMID: 12766478 DOI: 10.1023/a:1022974710488] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Apoptosis, or programmed cell death, is a well-ordered process that allows damaged or diseased cells to be removed from an organism without severe inflammatory reactions. Multiple factors, including microbial infection, can induce programmed death and trigger reactions in both host and microbial cellular pathways. Whereas an ultimate outcome is host cell death, these apoptotic triggering mechanisms may also facilitate microbial spread and prolong infection. To gain a better understanding of the complex events of host cell response to microbial infection, we investigated the molecular role of the microorganism Enteropathogenic Escherichia coli (EPEC) in programmed cell death. We report that wild type strain of EPEC, E2348/69, induced apoptosis in cultured PtK2 and Caco-2 cells, and in contrast, infections by the intracellularly localized Listeria monocytogenes did not. Fractionation and concentration of EPEC-secreted proteins demonstrated that soluble protein factors expressed by the bacteria were capable of inducing the apoptotic events in the absence of organism attachment, suggesting adherence is not required to induce host cell death. Among the known EPEC proteins secreted via the Type III secretion (TTS) system, we identified the translocated intimin receptor (Tir) in the apoptosis-inducing protein sample. In addition, host cell ectopic expression of an EPEC GFP-Tir showed mitochondrial localization of the protein and produced apoptotic effects in transfected cells. Taken together, these results suggest a potential EPEC Tir-mediated role in the apoptotic signaling cascade of infected host cells.
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Affiliation(s)
- H R Malish
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6058, USA
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34
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Freeman NL, Zurawski DV, Chowrashi P, Ayoob JC, Huang L, Mittal B, Sanger JM, Sanger JW. Interaction of the enteropathogenic Escherichia coli protein, translocated intimin receptor (Tir), with focal adhesion proteins. Cell Motil Cytoskeleton 2000; 47:307-18. [PMID: 11093251 DOI: 10.1002/1097-0169(200012)47:4<307::aid-cm5>3.0.co;2-q] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
When enteropathogenic Escherichia coli (EPEC) attach and infect host cells, they induce a cytoskeletal rearrangement and the formation of cytoplasmic columns of actin filaments called pedestals. The attached EPEC and pedestals move over the surface of the host cell in an actin-dependent reaction [Sanger et al., 1996: Cell Motil Cytoskeleton 34:279-287]. The discovery that EPEC inserts the protein, translocated intimin receptor (Tir), into the membrane of host cells, where it binds the EPEC outer membrane protein, intimin [Kenny et al., 1997: Cell 91:511-520], suggests Tir serves two functions: tethering the bacteria to the host cell and providing a direct connection to the host's cytoskeleton. The sequence of Tir predicts a protein of 56.8 kD with three domains separated by two predicted trans-membrane spanning regions. A GST-fusion protein of the N-terminal 233 amino acids of Tir (Tir1) binds to alpha-actinin, talin, and vinculin from cell extracts. GST-Tir1 also coprecipitates purified forms of alpha-actinin, talin, and vinculin while GST alone does not bind these three focal adhesion proteins. Biotinylated probes of these three proteins also bound Tir1 cleaved from GST. Similar associations of alpha-actinin, talin, and vinculin were also detected with the C-terminus of Tir, i.e., Tir3, the last 217 amino acids. Antibody staining of EPEC-infected cultured cells reveals the presence of focal adhesion proteins beneath the attached bacteria. Our experiments support a model in which the cytoplasmic domains of Tir recruit a number of focal adhesion proteins that can bind actin filaments to form pedestals. Since pedestals also contain villin, tropomyosin and myosin II [Sanger et al., 1996: Cell Motil. Cytoskeleton 34:279-287], the pedestals appear to be a novel structure sharing properties of both focal adhesions and microvilli.
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Affiliation(s)
- N L Freeman
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia 19104-6058, USA
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35
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Pachuk CJ, Ciccarelli RB, Samuel M, Bayer ME, Troutman RD, Zurawski DV, Schauer JI, Higgins TJ, Weiner DB, Sosnoski DM, Zurawski VR, Satishchandran C. Characterization of a new class of DNA delivery complexes formed by the local anesthetic bupivacaine. Biochim Biophys Acta 2000; 1468:20-30. [PMID: 11018648 DOI: 10.1016/s0005-2736(00)00242-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bupivacaine, a local anesthetic and cationic amphiphile, forms stable liposomal-like structures upon direct mixing with plasmid DNA in aqueous solutions. These structures are on the order of 50-70 nm as determined by scanning electron microscopy, and are homogeneous populations as analyzed by density gradient centrifugation. The DNA within these structures is protected from nuclease degradation and UV-induced damage in vitro. Bupivacaine:DNA complexes have a negative zeta potential (surface charge), homogeneous nature, and an ability to rapidly assemble in aqueous solutions. Bupivacaine:DNA complexes, as well as similar complexes of DNA with other local anesthetics, have the potential to be a novel class of DNA delivery agents for gene therapy and DNA vaccines.
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Affiliation(s)
- C J Pachuk
- Wyeth-Lederle Vaccines, 1 Great Valley Parkway, Malvern, PA 19355, USA.
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