Antibiotic adjuvant therapy for pulmonary infection in cystic fibrosis

Antibiotic adjuvant therapy for pulmonary infection in cystic fibrosis

BACKGROUND

Cystic fibrosis is a multi-system disease characterised by the production of thick secretions causing recurrent pulmonary infection, often with unusual bacteria. This leads to lung destruction and eventually death through respiratory failure. There are no antibiotics in development that exert a new mode of action and many of the current antibiotics are ineffective in eradicating the bacteria once chronic infection is established. Antibiotic adjuvants - therapies that act by rendering the organism more susceptible to attack by antibiotics or the host immune system, by rendering it less virulent or killing it by other means, would be a significant therapeutic advance. This is an update of a previously published review.

OBJECTIVES

To determine if antibiotic adjuvants improve clinical and microbiological outcome of pulmonary infection in people with cystic fibrosis.

SEARCH METHODS

We searched the Cystic Fibrosis Trials Register which is compiled from database searches, hand searches of appropriate journals and conference proceedings. Date of most recent search: 16 January 2020. We also searched MEDLINE (all years) on 14 February 2019 and ongoing trials registers on 06 April 2020.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials of a therapy exerting an antibiotic adjuvant mechanism of action compared to placebo or no therapy for people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two of the authors independently assessed and extracted data from identified trials.

MAIN RESULTS

We identified 42 trials of which eight (350 participants) that examined antibiotic adjuvant therapies are included. Two further trials are ongoing and five are awaiting classification. The included trials assessed β-carotene (one trial, 24 participants), garlic (one trial, 34 participants), KB001-A (a monoclonal antibody) (two trials, 196 participants), nitric oxide (two trials, 30 participants) and zinc supplementation (two trials, 66 participants). The zinc trials recruited children only, whereas the remaining trials recruited both adults and children. Three trials were located in Europe, one in Asia and four in the USA. Three of the interventions measured our primary outcome of pulmonary exacerbations (β-carotene, mean difference (MD) -8.00 (95% confidence interval (CI) -18.78 to 2.78); KB001-A, risk ratio (RR) 0.25 (95% CI 0.03 to 2.40); zinc supplementation, RR 1.85 (95% CI 0.65 to 5.26). β-carotene and KB001-A may make little or no difference to the number of exacerbations experienced (low-quality evidence); whereas, given the moderate-quality evidence we found that zinc probably makes no difference to this outcome. Respiratory function was measured in all of the included trials. β-carotene and nitric oxide may make little or no difference to forced expiratory volume in one second (FEV₁) (low-quality evidence), whilst garlic probably makes little or no difference to FEV₁ (moderate-quality evidence). It is uncertain whether zinc or KB001-A improve FEV₁ as the certainty of this evidence is very low. Few adverse events were seen across all of the different interventions and the adverse events that were reported were mild or not treatment-related (quality of the evidence ranged from very low to moderate). One of the trials (169 participants) comparing KB001-A and placebo, reported on the time to the next course of antibiotics; results showed there is probably no difference between groups, HR 1.00 (95% CI 0.69 to 1.45) (moderate-quality evidence). Quality of life was only reported in the two KB001-A trials, which demonstrated that there may be little or no difference between KB001-A and placebo (low-quality evidence). Sputum microbiology was measured and reported for the trials of KB001-A and nitric oxide (four trials). There was very low-quality evidence of a numerical reduction in Pseudomonas aeruginosa density with KB001-A, but it was not significant. The two trials looking at the effects of nitric oxide reported significant reductions in Staphylococcus aureus and near-significant reductions in Pseudomonas aeruginosa, but the quality of this evidence is again very low.

AUTHORS' CONCLUSIONS

We could not identify an antibiotic adjuvant therapy that we could recommend for treating of lung infection in people with cystic fibrosis. The emergence of increasingly resistant bacteria makes the reliance on antibiotics alone challenging for cystic fibrosis teams. There is a need to explore alternative strategies, such as the use of adjuvant therapies. Further research is required to provide future therapeutic options.

Role of Zinc Supplementation in the Improvement of Acute Respiratory Infections among Iranian Children: A Systematic Review

BACKGROUND

Respiratory infectious disease is considered as one of the most serious problems among children in developing countries. The importance of zinc in the improvement of respiratory disease has been indicated. However, there are some unanswered questions and uncertainty. This systematic review aimed at assessing the therapeutic benefits of zinc supplementation on respiratory infections of Iranian children.

MATERIALS AND METHODS

Databases, such as PubMed, Scopus, Embase, Magiran, and IranDoc, were searched for randomized controlled trials published from January 1998 to December 2017 on Zinc supplementation for the treatment or improvement of acute respiratory disease among Iranian children, during March 2018. Studies were screened according to the PICO framework, and irrelevant studies were excluded.

RESULTS

A total of 5 studies conducted on 522 children were included in this review. Except for one study, others had indicated the beneficial effect of zinc supplement on improving signs and symptoms of respiratory infectious disease and earlier discharge from the hospital.

CONCLUSION

Although studies on the efficacy of zinc on respiratory infectious disease of children in Iran have not widely considered and more studies should be conducted, all published articles (except for one of them) had indicated the effectiveness of zinc supplementation on respiratory infections among children. Other criteria, such as age, gender, birth weight, diet, and type of respiratory infections, should be considered during zinc therapy. Controlling these confounding variables and measuring the level of blood zinc are necessary to understand how much zinc should be prescribed for respiratory treatment of children.

Discrete choice experiment to evaluate preferences of patients with cystic fibrosis among alternative treatment-related health outcomes: a protocol

INTRODUCTION

Clinical decision-making is a complex process. Patient preference information regarding desirable health states should inform treatment and is critical to agreeing on goals of therapy. Cystic fibrosis (CF) is a common, inheritable multisystem disorder for which the major manifestation is progressive, chronic lung disease. Intermittent pulmonary exacerbations are a hallmark of disease and these drive lung damage that results in premature death. We suspect that clinicians make assumptions, most likely implicit assumptions, about outcomes that are desired by patients who are treated for pulmonary exacerbations. The aim of this study is to identify and quantify the preferences of patients with cystic fibrosis regarding treatment outcomes.

METHODS AND ANALYSIS

We will develop a discrete choice experiment (DCE) in collaboration with people with CF and their carers, and evaluate how patients make trade-offs between different aspects of health-related status when considering treatment options.

ETHICS AND DISSEMINATION

Ethics approval for all aspects of this study was granted by the Western Australia Child and Adolescent Health Service Human Research Ethics Committee [RGS903]. Weighted preference information from the DCE will be used to develop a multiattribute utility instrument as a measure of treatment success in the upcoming Bayesian Evidence-Adaptive Trial to optimise management of CF. Dissemination of results will also occur through peer-reviewed publications and presentations to relevant stakeholders and research networks.

Microbiome precision editing: Using PEG as a selective fermentation initiator against methicillin-resistant Staphylococcus aureus

Recent creation of a Unified Microbiome Initiative (UMI) has the aim of understanding how microbes interact with each other and with us. When pathogenic Staphylococcus aureus infects the skin, the interplay between S. aureus and skin commensal bacteria occurs. Our previous data revealed that skin commensal bacteria can mediate fermentation against the growth of USA300, a community-acquired methicillin-resistant S. aureus MRSA. By using a fermentation process with solid media on a small scale, we define poly(ethylene glycol) dimethacrylate (PEG-DMA) as a selective fermentation initiator which can specifically intensify the probiotic ability of skin commensal Staphylococcus epidermidis bacteria. At least five short-chain fatty acids including acetic, butyric and propionic acids with anti-USA300 activities are produced by PEG-DMA fermentation of S. epidermidis. Furthermore, the S. epidermidis-laden PEG-DMA hydrogels effectively decolonized USA300 in skin wounds in mice. The PEG-DMA and its derivatives may become novel biomaterials to specifically tailor the human skin microbiome against invading pathogens.

A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes

Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne.

Antimicrobial resistance in the respiratory microbiota of people with cystic fibrosis

Cystic fibrosis is characterised by chronic polymicrobial infection and inflammation in the airways of patients. Antibiotic treatment regimens, targeting recognised pathogens, have substantially contributed to increased life expectancy of patients with this disease. Although the emergence of antimicrobial resistance and selection of highly antibiotic-resistant bacterial strains is of major concern, the clinical relevance in cystic fibrosis is yet to be defined. Resistance has been identified in recognised cystic fibrosis pathogens and in other bacteria (eg, Prevotella and Streptococcus spp) detected in the airway microbiota, but their role in the pathophysiology of infection and inflammation in chronic lung disease is unclear. Increased antibiotic resistance in cystic fibrosis might be attributed to a range of complex factors including horizontal gene transfer, hypoxia, and biofilm formation. Strategies to manage antimicrobial resistance consist of new antibiotics or localised delivery of antimicrobial agents, iron sequestration, inhibition of quorum-sensing, and resistome analysis. Determination of the contributions of every bacterial species to lung health or disease in cystic fibrosis might also have an important role in the management of antibiotic resistance.

New perspectives in the management of Pseudomonas aeruginosa infections

ABSTRACT: 

Infections with Pseudomonas aeruginosa are a major health problem, especially for immune-compromised and cystic fibrosis patients, owing to the particular drug resistance of the microorganism. The aim of this review is to provide recent insights into strategies under investigation for prevention and therapy of these infections. In this survey, the approach directed against bacterial biofilm formation and quorum-sensing systems was focused, along with the evaluation of the treatment with bacteriophages. New interesting, developmental studies and clinical trials to prevent or treat infections due to this opportunistic pathogen are based on active and passive immunotherapy. Some monoclonal antibodies and different vaccines against this microorganism have been developed in the last few decades, even though to date none of them have obtained market authorization.