Key terms and definitions
| Term | Definition |
| Acquisition | In the context of CF, an organism is acquired when it is first detected in a respiratory sample (e.g. sputum or cough swab) |
| Active drying | In relation to drying of nebulisers, this term means to proactively promote drying by physical means such as drying with a cloth or forced hot air by means of a fan (e.g. in the case of a dishwasher) |
| Adherence | Patients' compliance with the correct drug prescription and their individualised routines |
| Aerosolised | The changing of a liquid medication into a mist that is subsequently delivered to the lungs by an appropriate device (e.g. nebuliser) |
| Air drying | Leaving respiratory devices including nebulisers to passively dry in air |
| Aseptic technique | Sterile manipulation to minimise risk of contamination |
| Antibiotic | A substance that acts specifically to kill bacteria (bactericidal) or to inhibit growth of bacteria (bacteriostatic) Ideally, the antibiotic should have minimal action on human cells Antibiotics are chosen to target different classes of bacteria and the various antibiotic groups act on the bacteria in different ways Antibiotics may be delivered orally, by injection into a muscle or vein or nebulised via the airways |
| Antifungal | A substance designed to kill or inhibit the growth of fungi |
| Biofilm | When microorganisms grow attached to a surface, they may produce a charged extracellular matrix with a high water content composed of polysaccharides and protein The resultant biofilm can protect the organisms from the normal host defence mechanisms and, since the components are polar in nature, the matrix may be impenetrable to antibiotics In mature biofilm, the oxygen tension may be low, allowing the growth of a mixed population of aerobic and anaerobic bacteria Such biofilm in the lumen of the bronchi in the CF lung may be the source of a periodic surge of bacteria in the airways precipitating a pulmonary exacerbation requiring intravenous antibiotic treatment |
| Burkholderia cenocepacia | B. cenocepacia is Gram-negative bacterium responsible for chronic respiratory disease in CF patients |
| Burkholderia cepacia complex | A group of ≥20 closely related bacterial species, many of which have been associated in the pathology of lung disease in CF patients The most important members of this complex include B. cenocepacia, B. multivorans and B. vietnamiensis |
| COPD | A lung disease characterised by chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible |
| Colonisation | Physical persistence of microorganisms in the airways, even in the presence of antibiotics This can subsequently lead to a state of chronic colonisation when a microorganism can be repeatedly detected in specimen from a body site Chronic colonisation may be marked by the finding of “mucoid” colonies of Pseudomonas aeruginosa or slow-growing “small-colony variants” of Staphylococcus aureus and such organisms may be impossible to eradicate using antibiotics In CF, chronic colonisation of the lungs by such organisms is usually associated with a clinical deterioration |
| Compressor | This is a device that compresses room air and forces it, by increased pressure and at a high velocity, through a liquid medicine to turn it into a mist of fine droplets which is then inhaled via a nebuliser |
| Contamination | The addition of microorganisms from the environment, other patients, healthcare workers or the patients themselves to a surface or object that did not previously contain such organisms |
| Detergent | A chemical that solubilises soil and dirt and helps clean (e.g. dishwashing liquid) Detergents generally have no antibacterial properties, unless antibacterial substances are specifically incorporated into their formulation and are marketed accordingly |
| Disinfectant | A chemical that is antimicrobial (e.g. chlorine tablets) and destroys vegetative forms of harmful microorganisms at the proper concentration (e.g. bacteria and fungi), especially on inanimate objects, but which may be less effective in destroying spores |
| Disinfection | The process (chemical, heat, ozone or ultraviolet light) by which a high percentage of the microorganisms are removed or killed from an object or surface This process will not inactivate bacterial/fungal spores and is less effective than sterilisation |
| Distilled water | Water that has been purified through boiling/evaporation and allowed to condense back into a liquid, thus removing many impurities |
| Environmental organism | Bacteria or fungi commonly detected from soil or water sources Although such organisms are often highly resistant to antibiotics, they are not usually included in the panel of clinically significant pathogens and not the target of bacterial culture in the clinical laboratory They do not usually colonise and cause infection except when there is a breach in the normal body defence against microorganisms In the CF lung, the proper function of the ciliary epithelium is compromised and CF patients are subject to colonisation by a succession of environmental bacteria and fungi To detect such organisms, extra resources are used by the clinical bacteriology laboratory processing CF respiratory samples |
| Eradication | After the initial acquisition of certain bacteria, concerted attempts are made to eliminate the bacteria, usually by means of repeated courses of antibiotics Early detection is the key to successful elimination and ideally, the treatment should be commenced as soon as possible after the organism is detected The declaration that a patient has been cleared of an organism is always retrospective and requires a period (e.g. 1 year) during which only negative samples are obtained |
| Evidence-based practice (EBP) | The conscientious, explicit and judicious use of current best evidence in making decisions about the care of patients EBP integrates best available external clinical evidence from systematic research |
| Microbiome | The sum of all the organisms in a region of the body Using molecular methods including PCR and genetic sequencing, hundreds of groups may be identified Studies of the microbiome in respiratory samples from CF patients show dynamic diversity of bacterial species When chronic colonisation occurs, species diversity decreases with high concentrations of the relatively few organisms, such as P. aeruginosa or B. cepacia |
| Mucociliary clearance | The removal of particles from the airways as the result of the movement of mucus due to the beating of the underlying cilia |
| Nebulised | Administering a drug to the airways or lungs in the form of an aerosolised mist of fine droplets |
| Nebuliser | A device that delivers aerosol droplets suitable for patient inhalation |
| Adaptive Aerosol Delivery | Small, quick devices that give improved deposition of medications by delivering an aerosol on inhalation during the individual’s breathing cycle (e.g. I-neb; Philips Respironics, Murrysville, PA, USA) |
| Disposable nebuliser | Discarded every 24 h |
| Jet nebuliser | Compressed air or oxygen used to aerosolise liquid medications |
| Reusable nebuliser | Can be used more than once |
| Vibrating mesh nebuliser | Moves liquid medication through a metal mesh to break up into a mist where each drop is a similar size, delivering a mist of medication constantly (e.g. E-flow; Pari, Byfleet, UK) |
| Nonpathogens | Organisms that do not cause disease, harm or death |
| Nosocomial infection | A hospital-acquired infection |
| Opportunistic organisms | Organisms that take advantage of certain opportunities to cause disease (e.g. a weakened immune system) |
| Pathogens/pathogenic organisms | Disease causing microorganisms, such as bacteria, fungi and viruses |
| Pseudomonas aeruginosa | A Gram-negative bacterium, commonly found in the environment, which is a significant pathogen in patients with CF |
| Potable water | Drinking water |
| Pulmonary exacerbation | An increase in respiratory symptoms (e.g. increased cough, sputum production or shortness of breath) accompanied by an acute decrease in lung function |
| Pulmonary infection | Worsening clinical symptoms or signs, caused by pathogens identified in respiratory secretion samples |
| Source/reservoir of infection | The principal habitat in which a specific infectious agent lives and multiplies The reservoir is necessary for the infectious agent either to survive or to multiply in sufficient amount to be transmitted to a susceptible host |
| Stenotrophomonas maltophilia | A Gram-negative bacterium identified in people with CF Although its clinical significance is a matter of debate, it is sometimes seen persistently in combination with other more significant pathogens such as P. aeruginosa or S. aureus In a few cases, this bacterium is the sole culminating organism in a CF patient with chronic pulmonary infection |
| Sterilisation | The process by which all microorganisms, including bacterial and fungal spores, are destroyed |
| Sterile water | Water is sterilised when it has been treated to destroy all microorganisms including bacterial and fungal spores |
| Transmission | The process of passing microorganisms from one person or place to another |