The Impact of Pseudomonas aeruginosa Infection in Adult Cystic Fibrosis Patients-A Single Polish Centre Study.

BACKGROUND: Pseudomonas aeruginosa (PA) is one of the most predominant pathogens of lung infections, often causing exacerbations in adult patients with cystic fibrosis (CF). MATERIALS AND METHODS: Microbiological characterization of 74 PA isolates and to evaluate the correlations between the bacterial features and 44 adult Polish CF cohort clinical parameters. RESULTS: The most common variant in the CF transmembrane conductance regulator (CFTR) gene was F508del (76.3%), followed by 3849+10kbC>T (26.3%). A total of 39.4% of the PA isolates showed multiple resistances. In patients with parameters pointing to a decline in lung function, there was a statistically significant moderate correlation with ß-lactam resistance and a weak correlation between hospital frequency and colistin resistance. The mucoidity did not correlate with the biofilm formation ability, which showed 41.9% of the isolates. Proteolytic activity, observed in 60.8% of the clinical isolates, was weakly associated with motility detected in 78.4% of the strains. The genetic profiles of the PA were highly heterogeneous, and a weak positive correlation was established between cluster group and biofilm formation. CONCLUSION: The findings suggest that there is a high variety in P. aeruginosa populations in adult CF patients. There is a need to monitor PA strains in groups of patients with cystic fibrosis, in particular, in terms of the occurrence of antibiotic resistance related to a decline in lung function.

Lethal Neonatal Respiratory Failure by Perinatal Transmission of Ureaplasma Parvum after Maternal PPROM.

A primiparous pregnant woman was admitted due to preterm premature rupture of membranes (PPROM) at 27+0 week of gestational age (WGA). Conventional vaginal microbiological analysis had no pathological finding. Management decisions based on national guidelines included antenatal corticoids, tocolytics and antibiotics. Unstoppable efforts of preterm labor in 28+0 WGA and supposed amniotic infection syndrome necessitated emergency cesarean section. The preterm infant underwent NICU therapy, developed an early-onset neonatal sepsis and therapy-refractory pulmonary insufficiency with consecutive right heart failure, resulting in death on the 36th day of life. Microbiota analyses by 16Sr DNA sequencing was performed from maternal vaginal swabs and from neonatal pharyngeal swabs. Maternal antibiotic treatment resulted in depletion of physiological vaginal colonization with Lactobacillus crispatus. Ureaplasma parvum became the dominant vaginal microorganism at delivery and was detected in high relative abundance in the neonatal specimen. Progressive radiological air-space changes and interstitial pathologies associated with Ureaplasma infection (bronchopulmonary dysplasia type III) were seen early at the 3rd and distinctly from 14th day of life. This clearly demonstrates the need of vaginal colonization diagnostics in PPROM patients and awareness of the consecutive risks in the preterm. Vaginal microbiome analysis may allow individualized and targeted maternal and fetal diagnostic, prophylactic and therapeutic strategies to identify, protect and treat the high-risk neonates after PPROM.

EBV miRNA expression profiles in different infection stages: A prospective cohort study.

The Epstein-Barr virus (EBV) produces different microRNAs (miRNA) with distinct regulatory functions within the infectious cycle. These viral miRNAs regulate the expression of viral and host genes and have been discussed as potential diagnostic markers or even therapeutic targets, provided that the expression profile can be unambiguously correlated to a specific stage of infection or a specific EBV-induced disorder. In this context, miRNA profiling becomes more important since the roles of these miRNAs in the pathogenesis of infections and malignancies are not fully understood. Studies of EBV miRNA expression profiles are sparse and have mainly focused on associated malignancies. This study is the first to examine the miRNA profiles of EBV reactivation and to use a correction step with seronegative patients as a reference. Between 2012 and 2017, we examined the expression profiles of 11 selected EBV miRNAs in 129 whole blood samples from primary infection, reactivation, healthy carriers and EBV seronegative patients. Three of the miRNAs could not be detected in any sample. Other miRNAs showed significantly higher expression levels and prevalence during primary infection than in other stages; miR-BHRF1-1 was the most abundant. The expression profiles from reactivation differed slightly but not significantly from those of healthy carriers, but a specific marker miRNA for each stage could not be identified within the selected EBV miRNA targets.

Polyester-based particles to overcome the obstacles of mucus and biofilms in the lung for tobramycin application under static and dynamic fluidic conditions.

Pulmonary infections with Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) are difficult to treat and related with high mortality in some diseases like cystic fibrosis due to the recurrent formation of biofilms. The biofilm formation hinders efficient treatment with inhaled antibiotics due to a low penetration of the antibiotics through the polyanionic biofilm matrix and increased antimicrobial resistance of the biofilm-embedded bacteria. In this study, tobramycin (Tb) was encapsulated in particles based on poly(d,l,-lactide-co-glycolide) (PLGA) and poly(ethylene glycol)-co-poly(d,l,-lactide-co-glycolide) diblock (PEG-PLGA) to overcome the biofilm barrier with particle sizes of 225-231 nm (nanoparticles) and 896-902 nm (microparticles), spherical shape and negative zeta potentials. The effectiveness against biofilms of P. aeruginosa and B. cepacia was strongly enhanced by the encapsulation under fluidic experimental condition as well as under static conditions in artificial mucus. The biofilm-embedded bacteria were killed by less than 0.77 mg/l encapsulated Tb, whereas 1,000 mg/l of free Tb or the bulk mixtures of Tb and the particles were ineffective against the biofilms. Moreover, encapsulated Tb was even effective against biofilms of the intrinsically aminoglycoside-resistant B. cepacia, indicating a supportive effect of PEG and PLGA on Tb. No cytotoxicity was detected in vitro in human lung epithelial cells with any formulation.

A blue fluorescent labeling technique utilizing micro- and nanoparticles for tracking in LIVE/DEAD® stained pathogenic biofilms of Staphylococcus aureus and Burkholderia cepacia.

Strategies that target and treat biofilms are widely applied to bacterial cultures using popular live/dead staining techniques with mostly red or green fluorescent markers (eg, with SYTO(®) 9, propidium iodide, fluorescein). Therefore, visualizing drugs or micro- and nanoparticulate delivery systems to analyze their distribution and effects in biofilms requires a third fluorescent dye that does not interfere with the properties of the live/dead markers. The present study establishes and evaluates a model for tracking polymeric particles in fluorescently stained biological material. To this end, poly(D,L-lactide-co-glycolide) (PLGA)-based micro- and nanoparticles were used as well-established model systems, which, because of their favorable safety profiles, are expected to play important future roles with regard to drug delivery via inhalation. PLGA was covalently and stably labeled with 7-amino-4-methyl-3-coumarinylacetic acid (AMCA), after which blue fluorescent poly(ethylene glycol)-block-PLGA (PEG-PLGA) particles were prepared using a mixture of fluorescent AMCA-PLGA and PEG-PLGA. Because chitosan is known to reduce negative surface charge, blue fluorescent PEG-PLGA-particles with chitosan were also prepared. These micro- and nanoparticles were physicochemically characterized and could be clearly distinguished from live/dead stained bacteria in biofilms using confocal laser scanning microscopy.

Aspects of pulmonary drug delivery strategies for infections in cystic fibrosis--where do we stand?

INTRODUCTION: Cystic fibrosis (CF) is the most common life-shortening hereditary disease among Caucasians and is associated with severe pulmonary damage because of decreased mucociliary clearance and subsequent chronic bacterial infections. Approximately 90% of CF patients die from lung destruction, promoted by pathogens such as Pseudomonas aeruginosa. Consequently, antibiotic treatment is a cornerstone of CF therapy, preventing chronic infection and reducing bacterial load, exacerbation rates and loss of pulmonary function. Many drugs are administered by inhalation to achieve high pulmonary concentration and to lower systemic side effects. However, pulmonary deposition of inhaled drugs is substantially limited by bronchial obstruction with viscous mucus and restrained by intrapulmonary bacterial biofilms. AREAS COVERED: This review describes challenges in the therapy of CF-associated infections by inhaled antibiotics and summarizes the current state of microtechnology and nanotechnology-based pulmonary antibiotic delivery strategies. Recent and ongoing clinical trials as well as experimental approaches for microparticle/nanoparticle-based antibiotics are presented and their advantages and disadvantages are discussed. EXPERT OPINION: Rapidly increasing antimicrobial resistance accompanied by the lack of novel antibiotics force targeted and more efficient use of the available drugs. Encapsulation of antimicrobials in nanoparticles or microparticles of organic polymers may have great potential for use in CF therapy.