Antibiotic Management of Lung Infections in Cystic Fibrosis. II. Nontuberculous Mycobacteria, Anaerobic Bacteria, and Fungi

Abstract

Airway infections are a key component of cystic fibrosis (CF) lung disease. Whereas the approach to common pathogens such as Pseudomonas aeruginosa is guided by a significant body of evidence, other infections often pose a considerable challenge to treating physicians. In Part I of this series on the antibiotic management of difficult lung infections, we discussed bacterial organisms including methicillin-resistant Staphylococcus aureus, gram-negative bacterial infections, and treatment of multiple bacterial pathogens. Here, we summarize the approach to infections with nontuberculous mycobacteria, anaerobic bacteria, and fungi. Nontuberculous mycobacteria can significantly impact the course of lung disease in patients with CF, but differentiation between colonization and infection is difficult clinically as coinfection with other micro-organisms is common. Treatment consists of different classes of antibiotics, varies in intensity, and is best guided by a team of specialized clinicians and microbiologists. The ability of anaerobic bacteria to contribute to CF lung disease is less clear, even though clinical relevance has been reported in individual patients. Anaerobes detected in CF sputum are often resistant to multiple drugs, and treatment has not yet been shown to positively affect patient outcome. Fungi have gained significant interest as potential CF pathogens. Although the role of Candida is largely unclear, there is mounting evidence that Scedosporium species and Aspergillus fumigatus, beyond the classical presentation of allergic bronchopulmonary aspergillosis, can be relevant in patients with CF and treatment should be considered. At present, however there remains limited information on how best to select patients who could benefit from antifungal therapy.

The basophil surface marker CD203c identifies Aspergillus species sensitization in patients with cystic fibrosis

“…Acute ABPA flares can be treated with intravenously administered pulsed methylprednisolone at 10-15 mg/kg/day for a three day period every month. 30,45 Methylprednisolone was administered to four CF-ABPA patients in this study and a trend towards reduction in Af-stimulated CD203c values was observed after treatment. However, this trend was not significant (P = 0.1604) warranting future longitudinal study with increased numbers to examine the effect of corticosteroid treatment on Af sensitization and potentially the use of the BAT to monitor treatment responses.…”

Nontuberculous Mycobacteria in Cystic Fibrosis

“…It was previously believed that NTM pulmonary infection developed exclusively in individuals following environmental acquisition, as mycobacteria, is ubiquitous in soil and water [28]. However, an outbreak of M. abscesses ssp massielense was first documented at a CF clinic in Seattle, Washington, involving five patients.…”

Fungal Infection of Cystic Fibrosis Patients—Single Center Experience

“…The results of the present study and other researches prove that fungi, particularly A. fumigatus species are a potential pathogen of severe invasive respiratory infections in CF patients [39]. Therefore, an efficient antifungal therapy in CF patients has to be preceded with mycological examination in order to determine etiology of infection and drug-sensitivity of the pathogen to antibiotics.…”