Discovery of inhibition of Burkholderia cenocepacia, Pseudomonas aeruginosa and Stenotrophomonas maltophilia by the Brown Rot Basidiomycete Fungus, Postia placenta.

Antimicrobial resistance (AMR) has now emerged as a major global public health problem. Certain bacterial pathogens, particularly Gram negative organisms associated with patients with cystic fibrosis (CF), have become resistant to several classes of antibiotics resulting in pan-resistance, which creates a clinical treatment dilemma. This study wished to explore the production of antibacterial extracellular metabolites from plant pathogenic fungi. Fungal Culture Extracts (FCEs) were prepared from 10 fungi (Armillaria gallica, Clitocybe nebularis, Fusarium coeruleum, Fusarium oxysporum, Fusarium poae, Hymenoscyphus fraxineus, Nectria fuckeliana, Phytophthora infestans, Phytophthora ramorum, Postia placenta), which were tested for activity against the CF pathogens, Pseudomonas aeruginosa (PA) (n=8), Burkholderia cenocepacia (n=2) and Stenotrophomonas maltophilia (n=2). In addition, FCE were assessed for their ability to alter antibiotic susceptibility in PA (n=8), with six antipseudomonal antibiotics (ceftazidime, ciprofloxacin, colistin, meropenem, piperacillin/tazobactam, tobramycin). None of the FCEs showed inhibitory activity to the 12 bacterial isolates tested, with the exception of the FCE from Postia placenta, which showed inhibition against all 12 bacteria. An antagonistic interaction was observed, where a statistically significant decrease in mean zone sizes was noted with Armillaria gallica (p=0.03) and Phytophthora infestans (p=0.03) FCEs and their interaction with the fluoroquinolone antibiotic, ciprofloxacin. Given the increase in clinical morbidity and mortality associated with chronic lung infections with Pseudomonas aeruginosa, Burkholderia cenocepacia and Stenotrophomonas maltophilia, coupled with the difficulty in treating such chronic infection due to overwhelming antimicrobial resistance, any novel substance showing inhibition of these organisms merits further investigation as a potential future antimicrobial agent, with potential clinical therapeutic application.

The Role of Suboptimal Concentrations of Nebulized Tobramycin in Driving Antimicrobial Resistance in Pseudomonas aeruginosa Isolates in Cystic Fibrosis.

BACKGROUND: Antimicrobial resistance in Pseudomonas aeruginosa may be driven by exposure to suboptimal concentrations of tobramycin antibiotic delivered by less efficient nebulizers. METHODS: P. aeruginosa isolates (no. = 114; 32 first + 82 chronic) were challenged in vitro employing extrapolated peak and trough concentrations of tobramycin inhalation solution (TIS), corresponding to 3 nebulizers: Pari LC Plus, Sidestream12NEB400, and MistyNeb2035G. Bacterial persistence and antibiotic susceptibility to tobramycin was determined following 4 TIS cycles: (i) 28 d ON, (ii) 28 d ON + 28 d OFF, (iii) 2 × 28 d ON, and (iv) 28 d ON + 28 d ON + 28 d OFF. RESULTS: All first isolates were eradicated at peak and trough concentrations except for the trough concentration corresponding to Sidestream 12NEB400 (bactericidal activity 87%). For chronic isolates, peak concentrations eradicated 88%, 90%, and 92%, and trough concentrations eradicated 43%, 62%, and 85%, with the Sidestream12NEB400, MistyNeb2035G, and Pari LC Plus nebulizers, respectively. A statistically significant increase in antibiotic resistance with sensitive, intermediate, and resistant P. aeruginosa was noted following cycles (i) through (iv) at trough concentrations with the Sidestream 12NEB400 and MistyNeb2035G nebulizers. There was a significant reduction in tobramycin resistance following a 28-d OFF cycle, and no difference was noted following 1 × 28 d ON versus 2 × 28 d ON cycles. CONCLUSIONS: Our results indicate that suboptimal concentrations of tobramycin drove increased antibiotic resistance, emulating standard cycles of ON/OFF inhaled therapy. This was evident at extrapolated tobramycin concentrations at trough levels corresponding to less efficient nebulizers by initially allowing for the survival of intermediate and resistant organisms, because nebulizer performance did not achieve critical antibiotic concentrations sufficient to eradicate the organism, and by allowing the development of resistance in those cells that were able to survive the initial tobramycin challenge. Transferred to clinical practice, for people with cystic fibrosis on TIS treatment, it is important that clinicians employ an efficient nebulizer that helps mitigate an upward drift in antibiotic resistance, thereby protecting the clinical value of TIS within treatment for cystic fibrosis.

The virtual CF clinic: Implications for sputum microbiology.

The COVID19 pandemic has shifted the paradigm of how outpatient clinics are delivered within CF care, resulting in a significant reduction of patient visits to CF centres. One consequence of this has been a reduction in the number of sputa/cough swabs that patients submit for routine analysis. This report examines why it is important to maintain optimal sputum microbiology and explores (i). the microbiological efficiency of postal submission of sputum specimens from the community and (ii) the regulatory conditions that must be met through postal submission of respiratory specimens. Virtual clinics have now been established within CF care and it is incumbent on each speciality within the CF MDT to explore ways to nurture and support their individual contribution to the success of the virtual clinic. Within microbiology, adopting innovative approaches to sputum collection in the community and transportation via postal services will allow for continued microbiological vigilance thereby supporting patient safety.

A simple preservation method for the storage of Aspergillus fumigatus and Scedosporium apiospermum filamentous fungi isolated from the sputum of patients with cystic fibrosis (CF).

A novel method is described for the laboratory storage of the filamentous fungi, Aspergillus fumigatus and Scedosporium apiospermum. These fungi were isolated directly from the sputum of patients with cystic fibrosis (CF) on previously described Medium B+ fungal selective agar. Medium B+ plates containing heavy growths of filamentous fungi were air dried to completeness and the resulting dehydrated agar containing fungi were hermetically sealed within A4 plastic lamination sheets using a domestic paper laminator. Fungi were successfully recovered and recultured post lamination. This method is simple, inexpensive, versatile and widely adaptable and requires minimum preparation/handling/processing, thereby encouraging the routine archiving of fungal isolates. Laminated fungal sheets may be catalogued and stored safely and securely in fireproof lockable filing cabinets in laboratories, thereby saving valuable bench- or freezer space.

Nebuliser hygiene in cystic fibrosis: evidence-based recommendations.

Nebulised therapies are extensively used in the daily therapeutic management of cystic fibrosis both for mucociliary clearance and for the management of chronic infections. Extensive developments have been made in relation to nebulised drug delivery mechanisms and drug formulations, and guidelines have been prepared that have addressed the appropriate use of such therapies. However, due to these developments, a plethora of nebuliser devices and drug chambers exist, and frequently, the limited guidance provided in relation to nebuliser hygiene is to follow manufacturers' instructions. Such instructions are inconsistent and at times confusing, translating to an increase in the burden associated with nebuliser maintenance. An evidence-based universal guideline relating to nebuliser care and hygiene is urgently required that is applicable to both at-home use and inpatient use. This article reviews the scientific literature in order to propose an evidence-based approach to nebuliser hygiene to ensure optimum drug delivery, and infection prevention and control. EDUCATIONAL AIMS: To understand the reasons why nebuliser hygiene is important.To give an overview of the current nebuliser care instructions that have been described by manufacturers, societies and the scientific literature.To outline the current nebuliser hygiene practices used by persons with cystic fibrosis in the home and hospital settings.To highlight areas that need further evaluation to promote optimum nebuliser care.To establish an evidence-based guideline for nebuliser hygiene in relation to cystic fibrosis.

Who's at The Door? - Surface Contamination of Door Frames in a Single-Bedded In-Patient Adult Cystic Fibrosis (CF) Unit.

The Gram-negative bacterium, Pseudomonas aeruginosa, is a major respiratory pathogen in patients with cystic fibrosis (CF), with an associated increase in morbidity and mortality. Consequently, infection prevention and control (IPC) plays an important role within health care in order to minimize the risk of cross-infection of this organism amongst patients and the hospital environment. It was the aim of this study to examine bacterial contamination of the health estate of CF in-patients' single-bedded rooms and related environments (n=40). Twelve bacterial genera were identified, six being Gram-positive (Brevibacterium, Dermacoccus, Micrococcus, Rothia, Staphylococcus and Streptococcus), and six being Gram-negative (Acinetobacter, Citrobacter, Klebsiella, Moraxella, Pantoea and Pseudoxanthomonas). None of the organisms identified were considered of particular clinical significance to CF patients. The CF lung and associated sputa may be important reservoirs of Pseudomonas aeruginosa, with potential for spill-over into the health care estate. In the aftermath of the Pseudomonas neonatal outbreak at Altnagelvin and the Royal Jubilee Maternity Hospitals, where there was heightened IPC awareness regarding the presence of this bacterium, it is encouraging to note its absence from the CF-health care estate examined.

Importance of Nebulizer Drying for Patients With Cystic Fibrosis.

BACKGROUND: Nebulizer therapy is an important treatment component for patients with cystic fibrosis (CF). Nebulizer manufacturers' guidelines advocate thorough nebulizer drying after washing. The aim of this study, therefore, was to examine the microbiology associated with nebulizer drying, particularly related to Pseudomonas control, and to examine microbiologically non-adherence to the recommended drying procedures. METHODS: Four aspects of nebulizer drying were examined in 3 common nebulizers, including examination of the drying profile, improvement to the drying profile of assembled nebulizers, survival of Pseudomonas aeruginosa in tap water and in tap water plus 0.5% (v/v) dishwashing detergent, and the effect of drying of P. aeruginosa in tap water and tap water plus residual sputum (1%v/v, 10%v/v). Microbiologic examination was performed by using P. aeruginosa (5 clinical CF strains plus 1 National Collection of Type Cultures Reference strain). RESULTS: There were differences in the time to complete dryness between disassembled and fully assembled nebulizers. Vigorous repeated shaking was unable to drive off all residual water on assembled nebulizers. P. aeruginosa counts did not decrease significantly in either tap water or in tap water plus detergent after 24 h storage at ambient temperature. In contrast, all Pseudomonas organisms were killed when nebulizers were dried for 24 h, even when contaminated with 1% and 10% sputum. Dishwashing detergent did not demonstrate any antibacterial activity. CONCLUSIONS: This study demonstrated that nebulizer drying, if applied properly, had the ability to reduce counts of P. aeruginosa to non-detectable levels. Equally, this study showed that, if the device was not dried thoroughly and moisture remained, then the device was able to support the survival of P. aeruginosa at high numbers, which constituted an infection risk to the patient with CF. This information may help educate and inform the patient with CF about the importance of proper nebulizer drying for Pseudomonas control to improve patient awareness and safety.

Nebuliser cleaning and disinfection practice in the home among patients with cystic fibrosis.

BACKGROUND: Nebulised delivery of different classes of drugs is of fundamental importance in therapeutic regimens relating to both the management of disease progression in cystic fibrosis disease and its associated complications. The aim of this study was to determine if current nebuliser hygiene practices in the home environment by paediatric and adult cystic fibrosis populations are appropriate to ensure appropriate infection control and prevention measures have been addressed. METHODS: An Audit Questionnaire Study was completed with adult cystic fibrosis patients (n=20) or with parents of cystic fibrosis children (n=24), through a healthcare professional interview on a one-to-one basis, during either a home visit or during patient/parent attendance at cystic fibrosis clinic. RESULTS: Hygienic practices relating to nebuliser care varied, with paediatric carers more likely to clean and disinfect their devices. This study suggests there is much variation and confusion with regard to how to clean and disinfect nebulisers, as well as who is responsible for delivering this advice. CONCLUSION: The adult cystic fibrosis community in particular needs to be educated on practicalities associated with nebuliser hygiene and the reasons why this is important. Furthermore, to date there is a lack of a universally recommended guideline suitable for all types of cystic fibrosis nebulisers that all relevant pharmaceutical manufacturers advocate.

Antimicrobial resistance (AMR) and marine plastics: Can food packaging litter act as a dispersal mechanism for AMR in oceanic environments?

This study examined the carriage of antibiotic resistance in bacteria isolated from Food-related Marine Macroplastic Litter (FRMMPL) around the coastline of Northern Ireland. FRMMPL was collected from 18 coastal sites during November/December 2018 and the bacteria from the surface of the plastic examined for their susceptibility to 10 common human antibiotics. Ten bacterial genera and 13 species were identified from the plastic materials. Bacteria isolated from plastic material were most resistant to the beta-lactam antibiotics (ampicillin, ceftazidime and cefpodoxime) (98.1% resistant) and least resistant to the tetracycline group, minocycline (16.1% resistant). This study is significant as it highlights a new potential route of dispersal of such antibiotic-resistance in the environment, which may act as carriers of such bacteria by introducing them into new marine ecosystems, as well as potential pathways having impacts on animal and human health, until their final interaction with the human foodchain.

Public Health Bacteriology of Commercially Composted Domestic Food and Garden Waste by the 11 Councils in Northern Ireland - Persistence Of Clostridium perfringens and Implications for Local Food Safety.

BACKGROUND: New legislation has been introduced in Northern Ireland from April 2017, requiring domestic households to recycle all domestic food waste items. The purpose of this study was to examine the bacteriology of compost derived from this source which is supplied free-of-charge to the public for horticultural use. METHODS: Municipal compost samples were compared microbiologically with commercial garden compost samples, examining total viable count and diversity of bacteria cultivated. RESULTS: The municipal compost had a mean Total Viable Count (TVC) of 1.53 × 108 colony forming units (cfu)/ g compost, whereas the commercial garden compost had a mean TVC of 4.5 × 107 cfu/g compost. Campylobacter, Salmonella and Listeria were not isolated from any compost. Twenty-three bacterial genera were represented amongst the 46 organisms recovered. Of these, Pseudomonas aeruginosa and Clostridium perfringens were the most clinically significant. DISCUSSION: The application of municipal compost to cultivate non-food plants, such as roses and flowers presents minimal risk, provided safe handling practices are adopted and hands are thoroughly washed and dried afterwards. However, if applied to soil growing food produce, it is important that municipal compost does not enter the food chain without an effective critical control point which would prevent germination of spores of Clostridium perfringens. Risk may be increased in products such as marinades, home canning, home bottling and associated products. These methods of food preparation are common in ethnic Eastern European populations in Northern Ireland, where awareness of risk needs to be increased.

Snow angels - the microbiology of freshly fallen snow: implications for immunocompromised patients.

The frequency of seasonal snowfall results in the transient covering of gardens/amenity sites/open public spaces, which encourages recreational interaction mainly with children. No data is available demonstrating the microbiological composition of such fallen snow and therefore a study was undertaken to examine the microbiology of snow from 37 sites, estimating (i) total viable count (TVC), (ii) identification of bacteria, and (iii) the presence of Pseudomonas aeruginosa. Mean TVC count of 8.3 colony-forming units (cfu)/ml snow melt water, 51.7 cfu/ml, 865 cfu/ml and 2,197 cfu/ml, was obtained for public amenity sites, domestic gardens, public open spaces and melting snow from public footpaths, respectively. No bacterial organisms (<10 cfu/ml) were detected in 5/14 (35.7%) open public spaces, 2/5 (40%) amenity sites and in 1/10 (10%) domestic gardens. Pseudomonas aeruginosa was not detected from any snow sample examined. Bacterial diversity consisted of 15 bacterial species (11 Gram-positive/four Gram-negative). The six Gram-positive genera identified from snow were Actinomyces, Bacillus, Brevibacillus, Micrococcus, Staphylococcus and Streptococcus. The four Gram-negative genera identified were Enterobacter, Pantoea, Pseudomonas and Xanthomonas. Bacillus licheniformis was the most commonly isolated organism from snow; it was isolated from every snow type. Snow may contain a diverse range of bacteria, many of which are capable of causing human infections.

Antimycobacterial activity of veterinary antibiotics (Apramycin and Framycetin) against Mycobacterium abscessus: Implication for patients with cystic fibrosis.

Background: Antimicrobial resistance has rendered certain species of Mycobacterium difficult to treat clinically, particularly the nontuberculous Mycobacterium and Mycobacterium abscessus. While veterinary medicine and human medicine share many classes of antibiotics, there are several antibiotics which are uniquely licensed to veterinary medicine but not human medicine. It was, therefore, the aim of this study to examine the action of eight veterinary antibiotics to a population of multi- and pan-resistant M. abscessus, isolated from the sputum of patients with cystic fibrosis (CF). Methods: Antibiotic susceptibility studies were performed on human clinical isolates of M. abscessus (n = 16), including 11 smooth isolates, 4 rough isolates, and 1 reference isolate (NCTC 13031), against the following 7 veterinary antibiotics (antibiotic class): apramycin (aminoglycoside), cefovecin (cephalosporin), ceftiofur (cephalosporin), framycetin (aminoglycoside), lincomycin (lincosamide), pirlimycin (lincosamide), and spectinomycin (aminocyclitol). Results: M. abscessus isolates were sensitive (100%) to apramycin and framycetin but resistant (100%) to cefovecin, ceftiofur, lincomycin, pirlimycin, and spectinomycin. Conclusion: This study identified that the veterinary aminoglycosides, apramycin, and framycetin, have in vitro activity against multi-resistant clinical isolates of M. abscessus. Further studies should now compare the activity of these antibiotics against amikacin and the human aminoglycoside, advocated in the treatment of disease in CF patients, to determine if these novel antibiotics have a future role for the development in human medicine with such chronic disease patients.

"Pathogen Eradication" and "Emerging Pathogens": Difficult Definitions in Cystic Fibrosis.

Infection is a common complication of cystic fibrosis (CF) airway disease. Current treatment approaches include early intervention with the intent to eradicate pathogens in the hope of delaying the development of chronic infection and the chronic use of aerosolized antibiotics to suppress infection. The use of molecules that help restore CFTR (cystic fibrosis transmembrane conductance regulator) function, modulate pulmonary inflammation, or improve pulmonary clearance may also influence the microbial communities in the airways. As the pipeline of these new entities continues to expand, it is important to define when key pathogens are eradicated from the lungs of CF patients and, equally important, when new pathogens might emerge as a result of these novel therapies.

Meningococcal ACWY vaccine uptake and awareness among student freshers enrolled at Northern Ireland universities.

A new MenACWY conjugate meningococcal vaccination programme was introduced in Northern Ireland (NI) in August 2015, for 13-18 year olds, as well as for first-time university entrants up to 25 years. This reflected the response made by Public Health England, due to the recent rapid increase of meningococcal group W (MenW) disease and on advice of the UK Joint Committee on Vaccination and Immunisation (JCVI). The aims of this study were to evaluate (i) the uptake of the MenACWY vaccine among first-time university students, (ii) vaccine and meningitis awareness, (iii) optimal communication modalities via a multidisciplinary team (MDT) model and (iv) current international vaccination policies relating to non-UK students. A survey was completed by 1210 students, 868 first-time freshers and 342 non-freshers, from healthcare-related, non-healthcare-related and engineering/computing faculties. The survey included an anonymous questionnaire and consented students were aged 17-50 years with a 2:3 ratio of male:female. Vaccine uptake amongst 18-year-old students was 90.7% and 87.3% in female and male cohorts, respectively, falling to 72.1% and 67.7% (19-year cohort) and 32.7% and 39.6% (20- to 25-year cohort) in males and females, respectively. Students reported that posters, clinics and talks were the preferred methods of communication and not social media. There was general lack of awareness of the signs/symptoms of meningitis and approximately 30% of students falsely believed that administration of the MenACWY vaccine excluded the risk of contracting meningitis. Overall, there was a successful vaccination campaign; however, there was a lack of meningitis awareness. Due to differing international meningococcal vaccination schedules, international students enrolling at UK universities need to be informed about current UK policies. For the successful introduction of any vaccination programme amongst university students, it is fundamental that a MDT is established to inform and deliver such a programme in an efficient and timely manner.