Exploring the dynamics of mixed-species biofilms involving Candida spp. and bacteria in cystic fibrosis.

Cystic fibrosis (CF) is an inherited disease that results from mutations in the gene responsible for the cystic fibrosis transmembrane conductance regulator (CFTR). The airways become clogged with thick, viscous mucus that traps microbes in respiratory tracts, facilitating colonization, inflammation and infection. CF is recognized as a biofilm-associated disease, it is commonly polymicrobial and can develop in biofilms. This review discusses Candida spp. and both Gram-positive and Gram-negative bacterial biofilms that affect the airways and cause pulmonary infections in the CF context, with a particular focus on mixed-species biofilms. In addition, the review explores the intricate interactions between fungal and bacterial species within these biofilms and elucidates the underlying molecular mechanisms that govern their dynamics. Moreover, the review addresses the multifaceted issue of antimicrobial resistance in the context of CF-associated biofilms. By synthesizing current knowledge and research findings, this review aims to provide insights into the pathogenesis of CF-related infections and identify potential therapeutic approaches to manage and combat these complex biofilm-mediated infections.

Evaluation of mixed biofilm production by Candida spp. and Staphylococcus aureus strains co-isolated from cystic fibrosis patients in northwest Algeria.

Cystic fibrosis patients' lungs are chronically colonized by multiple microbial species capable of forming biofilms. This study aimed to characterize the polymicrobial biofilm formed by Candida spp. and S. aureus, co-isolated from sputum samples of cystic fibrosis patients regarding microbial density, metabolic activity, and structure. 67 samples from 28 patients were collected with a 96% alteration rate. 34% showed alterations by both Candida spp. and Gram-positive bacteria, predominantly Candida spp. and S. aureus in 77% of cases, accounting for 6 associations. Biofilm biomass was quantified using the crystal violet assay, and metabolic activity was assessed using the MTT reduction assay. Scanning electron microscopy analyzed the C. tropicalis/S. aureus24 biofilm architecture. Candida spp. isolates demonstrated the ability to form mixed biofilms with S. aureus. The C. tropicalis/S. aureus24 association exhibited the highest production of biofilm and metabolic activity, along with the C. albicans17/C. rugosa/S. aureus7 in both single and mixed biofilms.

Initial characteristics of cystic fibrosis in Algeria: Description of 34 pediatric cases.

BACKGROUND: Cystic fibrosis (CF) is a rare disease in Algeria, and its prognosis is poor in developing countries. The clinical and demographic knowledge of Algerian pediatric patients diagnosed with CF is incomplete due to the nonexistence of a national medical registry. Hence, the present study is the first Algerian multicentre study on CF. METHODS: This retrospective study was conducted in western Algeria. Over 1 year, the study included all pediatric patients with a confirmed diagnosis of CF in the pediatric hospital of Oran. Patient characteristics, clinical manifestations, and the prescribed treatment were reported. RESULTS: Thirty-four children (16 boys and 18 girls) participated in this study. Only 15 were diagnosed before the age of 6 months. The sweat chloride test was positive in all patients. Respiratory manifestations were found in all patients, chronic diarrhoea in 29 of them, and growth retardation in 10. Moreover, 25 (73.5%) had low to low intermediate socioeconomic levels. After diagnosis, respiratory complications marked the evolution of the 34 patients, with bronchial congestion observed in 33 of them, while 10 (29.4%) patients presented severe bronchopneumonia and 4 (11.8%) were affected by asthma. Consequently,  three (8.8%) died at an average age of 9 years mainly because of respiratory failure. CONCLUSION: The prognosis of CF is poor in Algeria compared to other developed countries due to the longer diagnostic delay and limited therapeutic alternatives. This representative subset of Algerian pediatric patients with CF will serve as a reference for future studies on CF in Algeria.

In vitro evaluation of biofilm formation by Candida parapsilosis and Enterobacter cloacae. Scanning electron microscopy and efficacy of antimicrobial combinations study.

Fungal-bacterial infections are being increasingly recognized in clinical settings, and the interaction between these species in polymicrobial biofilms often lead to infections that are highly resistant to treatment. In this in vitro study, we analyzed the formation of mixed biofilms using clinically isolated Candida parapsilosis and Enterobacter cloacae. Additionally, we assessed the potential of conventional antimicrobials, both alone and in combination, for treating polymicrobial biofilms built by these human pathogens. Our results demonstrate that C. parapsilosis and E. cloacae are capable of forming mixed biofilms, as confirmed by scanning electron microscopy. Interestingly, we found that colistin alone or in combination with antifungal drugs was highly effective reducing up to 80% of the total biomass of polymicrobial biofilms.