Qualitative and quantitative microbiological analysis of sputa of 102 patients with cystic fibrosis

Abstract

A microbiological analysis of 102 patients suffering from cystic fibrosis was conducted over a 22 month period. 20 microbial species with the following incidence were identified: Pseudomonas aeruginosa: 83.4%; Candida albicans: 29.4%; Staphylococcus aureus: 24.5%; Staphylococcus epidermidis: 11.8%; Haemophilus influenzae: 11.8%; Streptococcus pneumoniae; 6.9%; Pseudomonas maltophilia: 6.8%; Aspergillus fumigatus: 5.9%. Other species were present in less than 5% of the patients. In the majority of specimens with P. aeruginosa, more than one type (up to six) was detectable. These strains were identical in colony appearance, O-serotype and pyocin-type. Quantitative analysis revealed concentrations of colony-forming units of 10(7) to 10(9) for P. aeruginosa, 10(6) to 10(8) for P. maltophilia, 10(4) to 10(7) for S. aureus, 10(4) to 10(6) for S. epidermidis and 10(4) to 10(7) for C. albicans in the majority of specimens. Significant differences were observed in the time periods during which the pathogens persisted in the patients. Maximum persistence was observed for P. aeruginosa. P. maltophilia and A. fumigatus had about similar persistence rates, which were lower than those for P. aeruginosa but above those for S. aureus and H. influenzae. S. epidermidis was eliminated within shorter periods than S. aureus. C. albicans, although the second most frequent microorganism identified, showed a very low persistence rate. The microbiological analysis confirms results from other research centers (high incidence of P. aeruginosa), but reveals significant regional differences as well (Pseudomonas cepacia not detectable, higher incidence of P. maltophilia and C. albicans). This underlines the necessity for detailed qualitative and quantitative microbiological analysis of sputa from cystic fibrosis patients as a prerequisite for rational analysis of etiological, epidemiological and therapeutical aspects of cystic fibrosis.

Interspecies competition triggers virulence and mutability in Candida albicans–Pseudomonas aeruginosa mixed biofilms

“…An in-depth understanding of these interactions could be exploited for the benefit of mankind. Pseudomonas and Candida are organisms that are commonly isolated from the sputum of cystic fibrosis patients (Hughes and Kim, 1973;Bauernfeind et al, 1987;Bakare et al, 2003). Both species are common nonpathogenic commensals of healthy individuals.…”

“…Both morphological forms are important for virulence, and the ability to undergo morphological transformation is therefore an important virulence trait (Gow, 1997;Calderone and Fonzi, 2001;Gow et al, 2002;Liu, 2002;Whiteway and Oberholzer, 2004). Several studies have suggested that P. aeruginosa may inhibit C. albicans growth within the host (Bauernfeind et al, 1987;Kerr, 1994;Burns et al, 1999;Gupta et al, 2005;Kaleli et al, 2007). Hogan and Kolter (2002) demonstrated that P. aeruginosa is cytotoxic to the filamentous form of C. albicans but is unable to attach to or kill C. albicans yeast cells.…”

Downregulation by a long-acting β2-adrenergic receptor agonist and corticosteroid of Staphylococcus aureus-induced airway epithelial inflammatory mediator production

“…infections and is often implicated in early infectious airway disease in cystic fibrosis patients (2,5,6,22). S. aureus expresses several potential virulence factors (VF) that may induce airway epithelial injury, inactivate host defense mechanisms, and impair the epithelial wound/repair process.…”

“…Alpha-toxin, one of the major soluble VF of S. aureus, is able to induce transient apoptosis followed by the necrosis of human airway epithelial cells (HAEC) (9). We have also recently shown that live S. aureus and more predominantly soluble VF in contact with HAEC induce marked alterations in the transcriptional expression profile of HAEC associated with activation of the NF-B and activator protein (AP)-1 pathway, upregulation of PGE 2 and cyclooxygenase (COX)-2 expression and proinflammatory cytokine release such as IL-1␤ and IL-8 (23). The role of the airway inflammation in the pathogenesis of chronic obstructive pulmonary diseases is well known, but the specific effects of S. aureus VF on the regulation of the inflammation have not been well defined.…”

Preimmunization Anti-Pneumococcal Antibody Levels Are Protective in a Majority of Patients With Cystic Fibrosis

“…7,8 This pneumococcal colonization has been documented to be transient in CF patients even in the absence of antibiotic therapy. 9,10 CF patients may have an attenuated antibody response to pneumococcus for the following reasons. Many CF patients have been treated, either prophylactically or intermittently, with oral and/or intravenous antibiotics, which usually cover S pneumoniae.…”