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Alipour-Khezri E, Skurnik M, Zarrini G. Pseudomonas aeruginosa Bacteriophages and Their Clinical Applications. Viruses 2024; 16:1051. [PMID: 39066214 PMCID: PMC11281547 DOI: 10.3390/v16071051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/25/2024] [Accepted: 06/26/2024] [Indexed: 07/28/2024] Open
Abstract
Antimicrobial resistance poses a serious risk to contemporary healthcare since it reduces the number of bacterial illnesses that may be treated with antibiotics, particularly for patients with long-term conditions like cystic fibrosis (CF). People with a genetic predisposition to CF often have recurrent bacterial infections in their lungs due to a buildup of sticky mucus, necessitating long-term antibiotic treatment. Pseudomonas aeruginosa infections are a major cause of CF lung illness, and P. aeruginosa airway isolates are frequently resistant to many antibiotics. Bacteriophages (also known as phages), viruses that infect bacteria, are a viable substitute for antimicrobials to treat P. aeruginosa infections in individuals with CF. Here, we reviewed the utilization of P. aeruginosa bacteriophages both in vivo and in vitro, as well as in the treatment of illnesses and diseases, and the outcomes of the latter.
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Affiliation(s)
- Elaheh Alipour-Khezri
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz 51368, Iran;
| | - Mikael Skurnik
- Human Microbiome Research Program, and Department of Bacteriology and Immunology, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland
| | - Gholamreza Zarrini
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz 51368, Iran;
- Microbial Biotechnology Research Group, University of Tabriz, Tabriz 51368, Iran
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Sathe N, Beech P, Croft L, Suphioglu C, Kapat A, Athan E. Pseudomonas aeruginosa: Infections and novel approaches to treatment "Knowing the enemy" the threat of Pseudomonas aeruginosa and exploring novel approaches to treatment. INFECTIOUS MEDICINE 2023; 2:178-194. [PMID: 38073886 PMCID: PMC10699684 DOI: 10.1016/j.imj.2023.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/30/2023] [Accepted: 05/05/2023] [Indexed: 03/09/2024]
Abstract
Pseudomonas aeruginosa is an aerobic Gram-negative rod-shaped bacterium with a comparatively large genome and an impressive genetic capability allowing it to grow in a variety of environments and tolerate a wide range of physical conditions. This biological flexibility enables the P. aeruginosa to cause a broad range of infections in patients with serious underlying medical conditions, and to be a principal cause of health care associated infection worldwide. The clinical manifestations of P. aeruginosa include mostly health care associated infections and community-acquired infections. P. aeruginosa possesses an array of virulence factors that counteract host defence mechanisms. It can directly damage host tissue while utilizing high levels of intrinsic and acquired antimicrobial resistance mechanisms to counter most classes of antibiotics. P. aeruginosa co-regulates multiple resistance mechanisms by perpetually moving targets poses a significant therapeutic challenge. Thus, there is an urgent need for novel approaches in the development of anti-Pseudomonas agents. Here we review the principal infections caused by P. aeruginosa and we discuss novel therapeutic options to tackle antibiotic resistance and treatment of P. aeruginosa infections that may be further developed for clinical practice.
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Affiliation(s)
- Nikhil Sathe
- Reliance Life Sciences Pvt. Ltd., Dhirubhai Ambani Life Sciences Centre, Thane Belapur Road, Rabale, Navi Mumbai 400701, India
- School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood Victoria 3125, Australia
| | - Peter Beech
- School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood Victoria 3125, Australia
| | - Larry Croft
- School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood Victoria 3125, Australia
| | - Cenk Suphioglu
- NeuroAllergy Research Laboratory, School of Life and Environmental Sciences, Deakin University, Geelong Campus at Waurn Ponds, 75 Pigdons Road, Waurn Ponds Victoria 3216, Australia
| | - Arnab Kapat
- Reliance Life Sciences Pvt. Ltd., Dhirubhai Ambani Life Sciences Centre, Thane Belapur Road, Rabale, Navi Mumbai 400701, India
| | - Eugene Athan
- School of Medicine, Deakin University, PO Box 281 Geelong 3220, Australia
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Hurley JC. Selective digestive decontamination-Con. Intensive Care Med 2023; 49:982-983. [PMID: 37386314 DOI: 10.1007/s00134-023-07146-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 06/17/2023] [Indexed: 07/01/2023]
Affiliation(s)
- James C Hurley
- Melbourne Medical School, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Melbourne, Australia.
- Internal Medicine Service, Ballarat Health, Grampians Health Services, PO Box 577, Ballarat, 3353, Australia.
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Hurley JC. Establishing the safety of selective digestive decontamination within the ICU population: a bridge too far? Trials 2023; 24:337. [PMID: 37198636 DOI: 10.1186/s13063-023-07356-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/21/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND Infection prevention interventions within the intensive care unit (ICU) setting, whether studied within quality improvement projects or cluster randomized trials (CRT), are seen as low risk and grounded in an ethical imperative. Selective digestive decontamination (SDD) appears highly effective at preventing ICU infections within randomized concurrent control trials (RCCTs) prompting mega-CRTs with mortality as the primary endpoint. FINDINGS Surprisingly, the summary results of RCCTs versus CRTs differ strikingly, being respectively, a 15-percentage-point versus a zero-percentage-point ICU mortality difference between control versus SDD intervention groups. Multiple other discrepancies are equally puzzling and contrary to both prior expectations and the experience within population-based studies of infection prevention interventions using vaccines. Could spillover effects from SDD conflate the RCCT control group event rate differences and represent population harm? Evidence that SDD is fundamentally safe to concurrent non-recipients in ICU populations is absent. A postulated CRT to realize this, the SDD Herd Effects Estimation Trial (SHEET), would require > 100 ICUs to achieve sufficient statistical power to find a two-percentage-point mortality spillover effect. Moreover, as a potentially harmful population-based intervention, SHEET would pose novel and insurmountable ethical issues including who is the research subject; whether informed consent is required and from whom; whether there is equipoise; the benefit versus the risk; considerations of vulnerable groups; and who should be the gatekeeper? CONCLUSION The basis for the mortality difference between control and intervention groups of SDD studies remains unclear. Several paradoxical results are consistent with a spillover effect that would conflate the inference of benefit originating from RCCTs. Moreover, this spillover effect would constitute to herd peril.
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Affiliation(s)
- James C Hurley
- Melbourne Medical School, University of Melbourne, Melbourne, Australia.
- Division of Internal Medicine, Grampians Health Services, Ballarat, VIC, Australia.
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Hurley JC. Structural equation modelling the impact of antimicrobials on the human microbiome. Colonization resistance versus colonization susceptibility as case studies. J Antimicrob Chemother 2023; 78:328-337. [PMID: 36512373 DOI: 10.1093/jac/dkac408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The impact of antimicrobials on the human microbiome and its relationship to human health are of great interest. How antimicrobial exposure might drive change within specific constituents of the microbiome to effect clinically relevant endpoints is difficult to study. Clinical investigation of each step within a network of causation would be challenging if done 'step-by-step'. An analytic tool of great potential to clinical microbiome research is structural equation modelling (SEM), which has a long history of applications to research questions arising within subject areas as diverse as psychology and econometrics. SEM enables postulated models based on a network of causation to be tested en bloc by confrontation with data derived from the literature. Case studies for the potential application of SEM techniques are colonization resistance (CR) and its counterpart, colonization susceptibility (CS), wherein specific microbes within the microbiome are postulated to either impede (CR) or facilitate (CS) invasive infection with pathogenic bacteria. These postulated networks have three causation steps: exposure to specific antimicrobials are key drivers, clinically relevant infection endpoints are the measurable observables and the activity of key microbiome constituents mediating CR or CS, which may be unobservable, appear as latent variables in the model. SEM methods have potential application towards evaluating the activity of specific antimicrobial agents within postulated networks of causation using clinically derived data.
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Affiliation(s)
- James C Hurley
- Melbourne Medical School, University of Melbourne, Melbourne, Victoria, Australia.,Division of Internal Medicine, Ballarat Health Services, Ballarat, Victoria, Australia
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Hurley JC. Structural equation modelling the relationship between anti-fungal prophylaxis and Pseudomonas bacteremia in ICU patients. Intensive Care Med Exp 2022; 10:2. [PMID: 35059904 PMCID: PMC8776977 DOI: 10.1186/s40635-022-00429-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/30/2021] [Indexed: 01/20/2023] Open
Abstract
Purpose Animal models implicate candida colonization facilitating invasive bacterial infections. The clinical relevance of this microbial interaction remains undefined and difficult to study directly. Observations from studies of anti-septic, antibiotic, anti-fungal, and non-decontamination-based interventions to prevent ICU acquired infection collectively serve as a natural experiment. Methods Three candidate generalized structural equation models (GSEM), with Candida and Pseudomonas colonization as latent variables, were confronted with blood culture and respiratory tract isolate data derived from 464 groups from 279 studies including studies of combined antibiotic and antifungal exposures within selective digestive decontamination (SDD) interventions. Results Introducing an interaction term between Candida colonization and Pseudomonas colonization substantially improved GSEM model fit. Model derived coefficients for singular exposure to anti-septic agents (− 1.23; − 2.1 to − 0.32), amphotericin (− 1.78; − 2.79 to − 0.78) and topical antibiotic prophylaxis (TAP; + 1.02; + 0.11 to + 1.93) versus Candida colonization were similar in magnitude but contrary in direction. By contrast, the model-derived coefficients for singular exposure to TAP, as with anti-septic agents, versus Pseudomonas colonization were weaker or non-significant. Singular exposure to amphotericin would be predicted to more than halve candidemia and Pseudomonas bacteremia incidences versus literature benchmarks for absolute differences of approximately one percentage point or less. Conclusion GSEM modelling of published data supports the postulated interaction between Candida and Pseudomonas colonization towards promoting bacteremia among ICU patients. This would be difficult to detect without GSEM modelling. The model indicates that anti-fungal agents have greater impact in preventing Pseudomonas bacteremia than TAP, which has no impact. Supplementary Information The online version contains supplementary material available at 10.1186/s40635-022-00429-8.
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Hurley JC. Selective digestive decontamination, a seemingly effective regimen with individual benefit or a flawed concept with population harm? CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:323. [PMID: 34470654 PMCID: PMC8408564 DOI: 10.1186/s13054-021-03744-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/24/2021] [Indexed: 02/07/2023]
Abstract
Selective digestive decontamination (SDD) regimens, variously constituted with topical antibiotic prophylaxis (TAP) and protocolized parenteral antibiotic prophylaxis (PPAP), appear highly effective for preventing ICU-acquired infections but only within randomized concurrent control trials (RCCT's). Confusingly, SDD is also a concept which, if true, implies population benefit. The SDD concept can finally be reified in humans using the broad accumulated evidence base, including studies of TAP and PPAP that used non-concurrent controls (NCC), as a natural experiment. However, this test implicates overall population harm with higher event rates associated with SDD use within the ICU context.
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Affiliation(s)
- James C Hurley
- Melbourne Medical School, University of Melbourne, Melbourne, Australia. .,Division of Internal Medicine, Ballarat Health Services, PO Box 577, Ballarat, VIC, 3353, Australia.
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Selective Digestive Decontamination Is Neither Safe Nor Efficacious for Critically Ill Patients. Crit Care Med 2021; 48:732-735. [PMID: 31567405 DOI: 10.1097/ccm.0000000000004047] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Mohammed HB, Rayyif SMI, Curutiu C, Birca AC, Oprea OC, Grumezescu AM, Ditu LM, Gheorghe I, Chifiriuc MC, Mihaescu G, Holban AM. Eugenol-Functionalized Magnetite Nanoparticles Modulate Virulence and Persistence in Pseudomonas aeruginosa Clinical Strains. Molecules 2021; 26:molecules26082189. [PMID: 33920270 PMCID: PMC8069135 DOI: 10.3390/molecules26082189] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 12/14/2022] Open
Abstract
Efficient antibiotics to cure Pseudomonas aeruginosa persistent infections are currently insufficient and alternative options are needed. A promising lead is to design therapeutics able to modulate key phenotypes in microbial virulence and thus control the progression of the infectious process without selecting resistant mutants. In this study, we developed a nanostructured system based on Fe3O4 nanoparticles (NPs) and eugenol, a natural plant-compound which has been previously shown to interfere with microbial virulence when utilized in subinhibitory concentrations. The obtained functional NPs are crystalline, with a spherical shape and 10-15 nm in size. The subinhibitory concentrations (MIC 1/2) of the eugenol embedded magnetite NPs (Fe3O4@EUG) modulate key virulence phenotypes, such as attachment, biofilm formation, persister selection by ciprofloxacin, and the production of soluble enzymes. To our knowledge, this is the first report on the ability of functional magnetite NPs to modulate P. aeruginosa virulence and phenotypic resistance; our data highlights the potential of these bioactive nanostructures to be used as anti-pathogenic agents.
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Affiliation(s)
- Hamzah Basil Mohammed
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
| | - Sajjad Mohsin I. Rayyif
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
| | - Carmen Curutiu
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
| | - Alexandra Catalina Birca
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest, 011061 Bucharest, Romania; (A.C.B.); (O.-C.O.)
| | - Ovidiu-Cristian Oprea
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest, 011061 Bucharest, Romania; (A.C.B.); (O.-C.O.)
| | - Alexandru Mihai Grumezescu
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
- Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, Politehnica University of Bucharest, 011061 Bucharest, Romania; (A.C.B.); (O.-C.O.)
| | - Lia-Mara Ditu
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
| | - Irina Gheorghe
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
| | - Grigore Mihaescu
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
| | - Alina-Maria Holban
- Microbiology & Immunology Department, Faculty of Biology, University of Bucharest, 77206 Bucharest, Romania; (H.B.M.); (S.M.I.R.); (C.C.); (L.-M.D.); (I.G.); (M.C.C.); (G.M.)
- Research Institute of the University of Bucharest—ICUB, University of Bucharest, 050657 Bucharest, Romania;
- Correspondence:
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Hurley JC. Is selective decontamination (SDD/SOD) safe in the ICU context? J Antimicrob Chemother 2021; 74:1167-1172. [PMID: 30753529 DOI: 10.1093/jac/dky573] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Multiple individual studies of selective digestive decontamination/selective oropharyngeal decontamination (SDD/SOD) among ICU patients appear to show potent infection prevention effects. Surprisingly, the event rates for multiple endpoints including ventilator-associated pneumonia, bacteraemia and candidaemia among concurrent control groups within SDD/SOD studies appear unusually high versus other rates in the literature. These paradoxical observations raise concern that the contextual effects of SDD/SOD, as postulated in the original SDD/SOD study, not only exist but also are strong. Until these effects are addressed within an optimally designed study, the safety of SDD/SOD within the 'whole of ICU' remains questionable.
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Affiliation(s)
- James C Hurley
- Rural Health Academic Center, Melbourne Medical School, University of Melbourne, Melbourne, Victoria, Australia.,Division of Internal Medicine, Ballarat Health Services, Ballarat, Victoria, Australia
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Hurley JC. Structural equation modeling the "control of gut overgrowth" in the prevention of ICU-acquired Gram-negative infection. Crit Care 2020; 24:189. [PMID: 32366267 PMCID: PMC7199305 DOI: 10.1186/s13054-020-02906-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Conceptually, the "control of gut overgrowth" (COGO) is key in mediating prevention against infection with Gram-negative bacilli by topical antibiotic prophylaxis, a common constituent of selective digestive decontamination (SDD) regimens. However, the relative importance of the other SDD components, enteral and protocolized parenteral antibiotic prophylaxis, versus other methods of infection prevention and versus other contextual exposures cannot be resolved within individual studies. METHODS Seven candidate generalized structural equation models founded on COGO concepts were confronted with Pseudomonas and Acinetobacter bacteremia as well as ventilator-associated pneumonia data derived from > 200 infection prevention studies. The following group-level exposures were included in the models: use and mode of antibiotic prophylaxis, anti-septic and non-decontamination methods of infection prevention; proportion receiving mechanical ventilation; trauma ICU; mean length of ICU stay; and concurrency versus non-concurrency of topical antibiotic prophylaxis study control groups. RESULTS In modeling Pseudomonas and Acinetobacter gut overgrowth as latent variables, anti-septic interventions had the strongest negative effect against Pseudomonas gut overgrowth but no intervention was significantly negative against Acinetobacter gut overgrowth. Strikingly, protocolized parenteral antibiotic prophylaxis and concurrency each have positive effects in the model, enteral antibiotic prophylaxis is neutral, and Acinetobacter bacteremia incidences are high within topical antibiotic prophylaxis studies, moreso with protocolized parenteral antibiotic prophylaxis exposure. Paradoxically, topical antibiotic prophylaxis (moreso with protocolized parenteral antibiotic prophylaxis) appears to provide the strongest summary prevention effects against overall bacteremia and overall VAP. CONCLUSIONS Structural equation modeling of published Gram-negative bacillus infection data enables a test of the COGO concept. Paradoxically, Acinetobacter and Pseudomonas bacteremia incidences are unusually high among studies of topical antibiotic prophylaxis.
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Affiliation(s)
- James C Hurley
- Melbourne Medical School, University of Melbourne, Melbourne, Australia.
- Internal Medicine Service, Ballarat Health Services, PO Box 577, Ballarat, Victoria, 3353, Australia.
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Discrepancies in Control Group Mortality Rates Within Studies Assessing Topical Antibiotic Strategies to Prevent Ventilator-Associated Pneumonia: An Umbrella Review. Crit Care Explor 2020; 2:e0076. [PMID: 32166296 PMCID: PMC7063908 DOI: 10.1097/cce.0000000000000076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Supplemental Digital Content is available in the text. Objectives: To test the postulate that concurrent control patients within ICUs studying topical oropharyngeal antibiotics to prevent ventilator-associated pneumonia and mortality would experience spillover effects from the intervention. Data Sources: Studies cited in 15 systematic reviews of various topical antibiotic and other infection prevention interventions among ICU patients. Study Selection: Studies of topical antibiotics, stratified into concurrent control versus nonconcurrent control designs. Studies of nondecontamination-based infection prevention interventions provide additional points of reference. Studies with no infection prevention intervention provide the mortality benchmark. Data from additional studies and data reported as intention to treat were used within sensitivity tests. Data Extraction: Mortality incidence proportion data, mortality census, study characteristics, group mean age, ICU type, and study publication year. Data Synthesis: Two-hundred six studies were included. The summary effect sizes for ventilator-associated pneumonia and mortality prevention derived in the 15 systematic reviews were replicated. The mean ICU mortality incidence for concurrent control groups of topical antibiotic studies (28.5%; 95% CI, 25.0–32.3; n = 41) is higher versus the benchmark (23.7%; 19.2–28.5%; n = 34), versus nonconcurrent control groups (23.5%; 19.3–28.3; n = 14), and versus intervention groups (24.4%; 22.1–26.9; n = 62) of topical antibiotic studies. In meta-regression models adjusted for group-level characteristics such as group mean age and publication year, concurrent control group membership within a topical antibiotic study remains associated with higher mortality (p = 0.027), whereas other group memberships, including membership within an antiseptic study, are each neutral (p = not significant). Conclusions: Within topical antibiotic studies, the concurrent control group mortality incidence proportions are inexplicably high, whereas the intervention group mortality proportions are paradoxically similar to a literature-derived benchmark. The unexplained ventilator-associated pneumonia and mortality excess in the concurrent control groups implicates spillover effects within studies of topical antibiotics. The apparent ventilator-associated pneumonia and mortality prevention effects require cautious interpretation.
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Hurley JC. Worldwide variation in Pseudomonas associated ventilator associated pneumonia. A meta-regression. J Crit Care 2019; 51:88-93. [PMID: 30771693 DOI: 10.1016/j.jcrc.2019.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/01/2019] [Accepted: 02/01/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE The objective here is to define the extent and possible reasons for geographic variation in Pseudomonas aeruginosa associated with Ventilator Associated Pneumonia (VAP). METHODS A random effects meta-regression model of Pseudomonas associated VAP incidence within the published literature was undertaken incorporating group level factors such trauma admission, year of publication and use of bronchoscopic sampling towards VAP diagnosis. RESULTS Pseudomonas associated VAP incidence was reported in 162 studies from seven worldwide regions published over 30 years. The highest incidence is among reports from the Middle East and Mediterranean being respectively 6.8; 5.2-9.0 (mean; 95% CI) and 6.9; 5.4-8.8 per 1000 mechanical ventilation (MV) days, versus that from North American ICU's (3.7; 2.3-5.9). In a meta-regression model, the variation in the incidence of Pseudomonas associated VAP was not significantly associated with bronchoscopic sampling in the diagnosis of VAP (p = 0.12) nor with admission to a trauma ICU (p = 0.13). CONCLUSION Pseudomonas associated VAP incidence among reports from six geographic regions worldwide varies by less than twofold with some decline by year of publication. Trauma ICU admission is a significant factor underlying variations in incidence of VAP overall but not Pseudomonas associated VAP.
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Affiliation(s)
- James C Hurley
- Department of Rural Health, Melbourne Medical School, University of Melbourne, Internal Medicine Service, Ballarat Health Services, Victoria, Australia.
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Hurley JC. Unusually High Incidences of Pseudomonas Bacteremias Within Topical Polymyxin-Based Decolonization Studies of Mechanically Ventilated Patients: Benchmarking the Literature. Open Forum Infect Dis 2018; 5:ofy256. [PMID: 30465011 PMCID: PMC6238150 DOI: 10.1093/ofid/ofy256] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/04/2018] [Indexed: 12/17/2022] Open
Abstract
Background Topical polymyxin (PM)–based regimens to decolonize patients receiving prolonged mechanical ventilation (MV) have been widely studied. However, paradoxical bacteremia incidences remain unexplained. Methods The literature was searched for studies of topical PM–based regimens used to decontaminate MV patients reporting incidences of overall and Pseudomonas bacteremia data. In addition, observational groups without any intervention and trials of various interventions other than topical PM (non-PM studies) served to provide external benchmarks and additional points of reference, respectively. The bacteremia incidences were extracted from the control and intervention (component) groups of these studies and compared with metaregression using generalized estimating equation methods. Results The summary odds ratio derived from studies of topical PM–based interventions against overall bacteremia was 0.60 (95% confidence interval [CI], 0.53–0.69). Benchmark incidences per 100 MV patients for overall (mean, 8.9%; 95% CI, 6.9% to 10.9%) and Pseudomonas (mean, 0.7%; 95% CI, 0.5% to 1.1%) bacteremia were derived from 16 observational studies. By contrast, among 17 studies of topical PM, the mean incidences among control groups for overall (mean, 15.3%; 95% CI, 11.5% to 20.3%) and Pseudomonas (mean, 1.6%; 95% CI, 0.9% to 3.1%) bacteremia were both higher, whereas these incidences in the intervention groups for both topical PM and non-PM studies were in each case more similar to the respective benchmarks. These paradoxical incidences cannot readily be explained in metaregression models. Conclusions Paradoxically, despite an apparent prevention effect of topical PM–based methods against bacteremia overall, the incidences of Pseudomonas bacteremia within the component groups of these studies are unusually high vs literature-derived benchmarks.
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Affiliation(s)
- James C Hurley
- Rural Health Academic Center, Melbourne Medical School, University of Melbourne, Ballarat, Victoria, Australia.,Rural Health Academic Center, Melbourne Medical School, University of Melbourne, Ballarat, Victoria, Australia.,Division of Internal Medicine, Ballarat Health Services, Ballarat, Victoria, Australia
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