Pneumocystis jirovecii and Cystic Fibrosis in Brittany, France.

Pneumocystis jirovecii is a transmissible fungus with a high pulmonary tropism. The prevalence of P. jirovecii in patients with cystic fibrosis (CF) has been estimated in Germany at 7.4%, in Spain at 21.5% and in Brazil at 38.2%. Data on the prevalence of P. jirovecii in CF patients in France remain scarce, particularly in Brittany, where the prevalence of CF is high (from 1/1600 to 1/4500). Our objectives were to determine the prevalence of colonization of the airways by P. jirovecii in Brittany in CF patients monitored at the "Centre de Ressources et de Compétences de la Mucoviscidose (CRCM)" of Rennes compared to that previously observed at the CRCM of Roscoff-Brest. Sputa from 86 patients (178 specimens) followed in Rennes were analyzed retrospectively. The detection of P. jirovecii was performed using real-time PCR targeting the gene encoding the mitochondrial large subunit of ribosomal RNA. Pneumocystis jirovecii DNA was detected in 3/86 patients (3.5%) monitored at Rennes, whereas it had previously been detected in 1/76 patients (1.3%) monitored at Roscoff-Brest, thus showing an overall prevalence of 2.5% in Brittany. These results obtained from two Breton centers taken together show that P. jirovecii prevalence in patients with CF in Brittany is lower than those observed in Germany, Spain, Brazil or in other regions of France. This study is a preliminary step in determining the risk factors for P. jirovecii acquisition, its epidemiological and clinical significance in CF patients through a prospective multicenter study.

An observational study of anaerobic bacteria in cystic fibrosis lung using culture dependant and independent approaches.

Strict anaerobes are undeniably important residents of the cystic fibrosis (CF) lung but are still unknowns. The main objectives of this study were to describe anaerobic bacteria diversity in CF airway microbiota and to evaluate the association with lung function. An observational study was conducted during eight months. A hundred and one patients were enrolled in the study, and 150 sputum samples were collected using a sterile sample kit designed to preserve anaerobic conditions. An extended-culture approach on 112 sputa and a molecular approach (quantitative PCR targeting three of the main anaerobic genera in CF lung: Prevotella, Veillonella, and Fusobacterium) on 141 sputa were developed. On culture, 91.1% of sputa were positive for at least one anaerobic bacterial species, with an average of six anaerobic species detected per sputum. Thirty-one anaerobic genera and 69 species were found, which is the largest anaerobe diversity ever reported in CF lungs. Better lung function (defined as Forced Expiratory Volume in one second > 70%) was significantly associated with higher quantification of Veillonella. These results raise the question of the potential impact of anaerobes on lung function.

In Vitro Activity of 22 Antibiotics against Achromobacter Isolates from People with Cystic Fibrosis. Are There New Therapeutic Options?

Bacteria belonging to the genus Achromobacter are increasingly isolated from respiratory samples of people with cystic fibrosis (PWCF). The management of this multidrug-resistant genus is challenging and characterised by a lack of international recommendations, therapeutic guidelines and data concerning antibiotic susceptibility, especially concerning the newer antibiotics. The objective of this study was to describe the antibiotic susceptibility of Achromobacter isolates from PWCF, including susceptibility to new antibiotics. The minimum inhibitory concentrations (MICs) of 22 antibiotics were determined for a panel of 23 Achromobacter isolates from 19 respiratory samples of PWCF. Two microdilution MIC plates were used: EUMDROXF® plate (Sensititre) and Micronaut-S Pseudomonas MIC® plate (Merlin) and completed by a third method if necessary (E-test® or UMIC®). Among usual antimicrobial agents, the most active was imipenem (70% susceptibility). Trimethoprim-sulfamethoxazole, piperacillin and tigecycline (65%, 56% and 52% susceptibility, respectively) were still useful for the treatment of Achromobacter infections. Among new therapeutic options, ß-lactams combined with a ß-lactamase-inhibitor did not bring benefits compared to ß-lactam alone. On the other hand, cefiderocol appeared as a promising therapeutic alternative for managing Achromobacter infections in PWCF. This study provides the first results on the susceptibility of clinical Achromobacter isolates concerning new antibiotics. More microbiological and clinical data are required to establish the optimal treatment of Achromobacter infections.

Prevalence and dynamics of Lactobacillus sp. in the lower respiratory tract of patients with cystic fibrosis.

No prevalence or dynamics analysis of Lactobacilli in the lung of cystic fibrosis (CF) patients has yet been conducted. In order to use them as probiotics in the treatment of Pseudomonas aeruginosa infection, we describe their lung epidemiology. Over a period of 8 months, we analyzed 279 sputum samples from 124 CF patients classified according to their P. aeruginosa Leeds status of colonization. A total of 137 strains belonging to 11 species were isolated. The prevalence of carriage was 61%. No difference in species diversity or frequency was observed according to Leeds criteria. The next step will be to focus on the strain level.