1
|
Barnes KB, Brett P, Burtnick M, Vente A, Bentley C, Richards MI, Flick-Smith HC, Burgess G, Thwaite JE, Laws TR, Maishman TC, Nelson M, Harding SV. Layering vaccination with antibiotic therapy results in protection and clearance of Burkholderia pseudomallei in Balb/c mice. Infect Immun 2024; 92:e0045523. [PMID: 38289122 DOI: 10.1128/iai.00455-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/09/2024] [Indexed: 03/13/2024] Open
Abstract
Melioidosis is a disease that is difficult to treat due to the causative organism, Burkholderia pseudomallei being inherently antibiotic resistant and it having the ability to invade, survive, and replicate in an intracellular environment. Combination therapy approaches are routinely being evaluated in animal models with the aim of improving the level of protection and clearance of colonizing bacteria detected. In this study, a subunit vaccine layered with the antibiotic finafloxacin was evaluated in vivo against an inhalational infection with B. pseudomallei in Balb/c mice. Groups of mice vaccinated, infected, and euthanized at antibiotic initiation had a reduced bacterial load compared to those that had not been immunized. In addition, the subunit vaccine provided a synergistic effect when it was delivered with a CpG ODN and finafloxacin was initiated at 48 h post-challenge. Vaccination was also shown to improve the outcome, in a composite measure of survival and clearance. In summary, layering a subunit vaccine with the antibiotic finafloxacin is a promising therapeutic alternative for use in the treatment of B. pseudomallei infections.
Collapse
Affiliation(s)
- Kay B Barnes
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Paul Brett
- University of Nevada, Reno School of Medicine, Reno, Nevada, USA
- Mahidol University, Bangkok, Thailand
| | - Mary Burtnick
- University of Nevada, Reno School of Medicine, Reno, Nevada, USA
- Mahidol University, Bangkok, Thailand
| | | | | | - Mark I Richards
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Helen C Flick-Smith
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Gary Burgess
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Joanne E Thwaite
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Thomas R Laws
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Thomas C Maishman
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Michelle Nelson
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Sarah V Harding
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
- University of Leicester, Leicester, United Kingdom
| |
Collapse
|
2
|
Clay KA, Hartley MG, Whelan AO, Bailey MS, Norville IH. Evaluation of Alternative Doxycycline Antibiotic Regimes in an Inhalational Murine Model of Q Fever. Antibiotics (Basel) 2023; 12:antibiotics12050914. [PMID: 37237817 DOI: 10.3390/antibiotics12050914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/11/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
The timing of the initiation of antibiotic treatment has been shown to impact the clinical outcome of many bacterial infections, including Q fever. Delayed, suboptimal or incorrect antibiotic treatment has been shown to result in poor prognosis, resulting in the progression of acute disease to long-term chronic sequalae. Therefore, there is a requirement to identify an optimal, effective therapeutic regimen to treat acute Q fever. In the study, the efficacies of different doxycycline monohydrate regimens (pre-exposure prophylaxis, post-exposure prophylaxis or treatment at symptom onset or resolution) were evaluated in an inhalational murine model of Q fever. Different treatment lengths (7 or 14 days) were also evaluated. Clinical signs and weight loss were monitored during infection and mice were euthanized at different time points to characterize bacterial colonization in the lungs and the dissemination of bacteria to other tissues including the spleen, brain, testes, bone marrow and adipose. Post-exposure prophylaxis or doxycycline treatment starting at symptoms onset reduced clinical signs, and also delayed the systemic clearance of viable bacteria from key tissues. Effective clearance was dependent on the development of an adaptive immune response, but also driven by sufficient bacterial activity to maintain an active immune response. Pre-exposure prophylaxis or post-exposure treatment at the resolution of clinical signs did not improve outcomes. These are the first studies to experimentally evaluate different doxycycline treatment regimens for Q fever and illustrate the need to explore the efficacy of other novel antibiotics.
Collapse
Affiliation(s)
- Kate A Clay
- Academic Department, Royal Centre for Defence Medicine (Academia and Research), Birmingham B15 2GW, UK
| | - M Gill Hartley
- CBR Division, Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury SP4 0JQ, UK
| | - Adam O Whelan
- CBR Division, Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury SP4 0JQ, UK
| | - Mark S Bailey
- Academic Department, Royal Centre for Defence Medicine (Academia and Research), Birmingham B15 2GW, UK
| | - Isobel H Norville
- CBR Division, Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury SP4 0JQ, UK
- Department of Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| |
Collapse
|
3
|
Barnes KB, Bayliss M, Davies C, Richards MI, Laws TR, Vente A, Harding SV. Efficacy of finafloxacin in a murine model of inhalational glanders. Front Microbiol 2022; 13:1057202. [PMID: 36504783 PMCID: PMC9730244 DOI: 10.3389/fmicb.2022.1057202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022] Open
Abstract
Burkholderia mallei, the causative agent of glanders, is principally a disease of equines, although it can also infect humans and is categorized by the U.S. Centers for Disease Control and Prevention as a category B biological agent. Human cases of glanders are rare and thus there is limited information on treatment. It is therefore recommended that cases are treated with the same therapies as used for melioidosis, which for prophylaxis, is co-trimoxazole (trimethoprim/sulfamethoxazole) or co-amoxiclav (amoxicillin/clavulanic acid). In this study, the fluoroquinolone finafloxacin was compared to co-trimoxazole as a post-exposure prophylactic in a murine model of inhalational glanders. BALB/c mice were exposed to an aerosol of B. mallei followed by treatment with co-trimoxazole or finafloxacin initiated at 24 h post-challenge and continued for 14 days. Survival at the end of the study was 55% or 70% for mice treated with finafloxacin or co-trimoxazole, respectively, however, this difference was not significant. However, finafloxacin was more effective than co-trimoxazole in controlling bacterial load within tissues and demonstrating clearance in the liver, lung and spleen following 14 days of therapy. In summary, finafloxacin should be considered as a promising alternative treatment following exposure to B. mallei.
Collapse
Affiliation(s)
- Kay B. Barnes
- Defence Science and Technology Laboratory, Salisbury, United Kingdom,*Correspondence: Kay B. Barnes,
| | - Marc Bayliss
- Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Carwyn Davies
- Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Mark I. Richards
- Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Thomas R. Laws
- Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | | | - Sarah V. Harding
- Defence Science and Technology Laboratory, Salisbury, United Kingdom,Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
| |
Collapse
|
4
|
An Investigation into the Re-Emergence of Disease Following Cessation of Antibiotic Treatment in Balb/c Mice Infected with Inhalational Burkholderia pseudomallei. Antibiotics (Basel) 2022; 11:antibiotics11101442. [PMID: 36290100 PMCID: PMC9598772 DOI: 10.3390/antibiotics11101442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 11/17/2022] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, a multifaceted disease. A proportion of the mortality and morbidity reported as a result of infection with this organism may be due to the premature cessation of antibiotic therapy typically lasting for several months. The progression of re-emergent disease was characterised in Balb/c mice following cessation of a 14 day treatment course of co-trimoxazole or finafloxacin, delivered at a human equivalent dose. Mice were culled weekly and the infection characterised in terms of bacterial load in tissues, weight loss, clinical signs of infection, cytokine levels and immunological cell counts. Following cessation of treatment, the infection re-established in some animals. Finafloxacin prevented the re-establishment of the infection for longer than co-trimoxazole, and it is apparent based on the protection offered, the development of clinical signs of disease, bodyweight loss and bacterial load, that finafloxacin was more effective at controlling infection when compared to co-trimoxazole.
Collapse
|
5
|
Barnes KB, Richards MI, Burgess G, Armstrong SJ, Bentley C, Maishman TC, Laws TR, Nelson M, Harding SV. Investigation of a combination therapy approach for the treatment of melioidosis. Front Microbiol 2022; 13:934312. [PMID: 36051754 PMCID: PMC9424925 DOI: 10.3389/fmicb.2022.934312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
The efficacy of finafloxacin as a component of a layered defense treatment regimen was determined in vitro and in vivo against an infection with Burkholderia pseudomallei. Doxycycline was down-selected from a panel of antibiotics evaluated in vitro and used in combination with finafloxacin in a Balb/c mouse model of inhalational melioidosis. When treatment was initiated at 24 h post-infection with B. pseudomallei, there were no differences in the level of protection offered by finafloxacin or doxycycline (as monotherapies) when compared to the combination therapy. There was evidence for improved bacterial control in the groups treated with finafloxacin (as monotherapies or in combination with doxycycline) when compared to mice treated with doxycycline. Survival comparisons of finafloxacin and doxycycline (as monotherapies) or in combination initiated at 36 h post-infection indicated that finafloxacin was superior to doxycycline. Doxycycline was also unable to control the levels of bacteria within tissues to the extent that doxycycline and finafloxacin used in combination or finafloxacin (as a sole therapy) could. In summary, finafloxacin is a promising therapy for use in the event of exposure to B. pseudomallei.
Collapse
Affiliation(s)
- Kay B. Barnes
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Mark I. Richards
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Gary Burgess
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Stuart J. Armstrong
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | | | - Thomas C. Maishman
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Thomas R. Laws
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Michelle Nelson
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Sarah V. Harding
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
- Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
| |
Collapse
|