Escherichia coli A0 34/86 (EcO83) is a probiotic strain used in newborns to prevent nosocomial infections and diarrhoea. This bacterium stimulates both pro- and anti-inflammatory cytokine production and its intranasal administration reduces allergic airway inflammation in mice. Despite its benefits, there are concerns about the use of live probiotic bacteria due to potential systemic infections and gene transfer. Extracellular vesicles (EVs) derived from EcO83 (EcO83-EVs) might offer a safer alternative to live bacteria. This study characterizes EcO83-EVs and investigates their interaction with host cells, highlighting their potential as postbiotic therapeutics. EcO83-EVs were isolated, purified, and characterised following the Minimal Information of Studies of Extracellular Vesicles (MISEV) guidelines. Ex vivo studies conducted in human nasal epithelial cells showed that EcO83-EVs increased the expression of proteins linked to oxidative stress and inflammation, indicating an effective interaction between EVs and the host cells. Further in vivo studies in mice demonstrated that EcO83-EVs interact with nasal-associated lymphoid tissue, are internalised by airway macrophages, and stimulate neutrophil recruitment in the lung. Mechanistically, EcO83-EVs activate the NF-κΒ signalling pathway, resulting in the nitric oxide production. EcO83-EVs demonstrate significant potential as a postbiotic alternative to live bacteria, offering a safer option for therapeutic applications. Further research is required to explore their clinical use, particularly in mucosal vaccination and targeted immunotherapy strategies.

• Klíčová slova
• EVs, Ec083, NF‐κΒ signalling, bacterial extracellular vesicles, macrophage, nitric oxide, postbiotics, probiotic,
• MeSH
• aplikace intranazální * MeSH
• epitelové buňky metabolismus   MeSH
• Escherichia coli * metabolismus   MeSH
• extracelulární vezikuly * metabolismus   MeSH
• lidé MeSH
• lymfoidní tkáň metabolismus   MeSH
• makrofágy metabolismus   MeSH
• myši MeSH
• NF-kappa B metabolismus   MeSH
• oxidační stres MeSH
• plíce mikrobiologie   metabolismus   MeSH
• probiotika * aplikace a dávkování   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• NF-kappa B MeSH

Pertussis (whooping cough) is a highly transmissible human respiratory disease caused by Bordetella pertussis, a human-restricted pathogen. Animal models generally involve pneumonic infections induced by depositing large numbers of bacteria in the lungs of mice. These models have informed us about the molecular pathogenesis of pertussis and guided development of vaccines that successfully protect against severe disease. However, they bypass the catarrhal stage of the disease, when bacteria first colonize and initially grow in the upper respiratory tract. This is a critical and highly transmissible stage of the infection that current vaccines do not prevent. Here, we demonstrate a model system in which B. pertussis robustly and persistently infects the nasopharynx of TLR4-deficient mice, inducing localized inflammation, neutrophil recruitment and mucus production as well as persistent shedding and occasional transmission to cage mates. This novel experimental system will allow the study of the contributions of bacterial factors to colonization of and shedding from the nasopharynx, as occurs during the catarrhal stage of pertussis, and interventions that might better control the ongoing circulation of pertussis.

• Klíčová slova
• Bordetella pertussis, Catarrhal stage, Mouse, Shedding, TLR4 receptor,
• MeSH
• Bordetella pertussis MeSH
• infekce dýchací soustavy * MeSH
• myši MeSH
• pertuse * mikrobiologie   prevence a kontrola   MeSH
• pertusová vakcína MeSH
• plíce mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• pertusová vakcína MeSH

BACKGROUND: Cilia-associated respiratory bacillus (CARB; now known as Filobacterium rodentium gen. nov., sp. nov.) is a primary pathogen of rodents. A CARB-like organism was reported in post-mortem lung samples of cats using light and electron microscopy. Here we explore by molecular procedures if a Filobacterium sp. is a part of the normal feline lower respiratory microbiome and whether it could in some cats contribute to the development of chronic bronchial disease. METHODOLOGY: A Filobacterium sp. was identified in three Czech cats clinically diagnosed as having chronic neutrophilic bronchitis. Bronchoalveolar lavage fluid (BALF) specimens obtained from these cats were subjected to panbacterial 16S rDNA PCR followed by Sanger sequencing of the V5 to V8 region. After these cats were treated with specific antimicrobials, their clinical signs resolved promptly, without recurrence. Next, BALF specimens from 13 Australian and 11 Italian cats with lower respiratory disease and an additional 16 lung samples of Italian cats who died of various causes were examined using next generation sequencing (NGS). Subsequently, a Filobacterium-specific qPCR assay was developed and used to re-test BALF specimens from the 11 Italian cats and lung tissue homogenates from the additional 16 deceased cats. PRINCIPAL FINDINGS: An amplicon of 548 bp with 91.24% sequence agreement with Filobacterium rodentium was obtained from all three patients, suggesting the novel Filobacterium sp. was the cause of their lower respiratory disease. The novel Filobacterium sp., which we propose to call F. felis, was detected in 3/3 Czech cats with chronic neutrophilic bronchitis, 13/13 Australian cats and 6/11 Italian cats with chronic lower respiratory disease, and 14/16 necropsy lung specimens from Italian cats. NGS and qPCR results all showed identical sequences. The Filobacterium sp. was sometimes the preponderant bacterial species in BALF specimens from cats with lower airway disease. There was an association between the presence of large numbers (greater than 105 organisms/mL) of Filobacterium and the presence of neutrophilic and/or histiocytic inflammation, although only a subset of inflammatory BALF specimens had F. felis as the preponderant organism. CONCLUSION: The novel Filobacterium sp. comprises a finite part of the normal feline lower respiratory microbiome. Under certain circumstances it can increase in absolute and relative abundance and give rise to neutrophilic and/or histiocytic bronchitis, bronchiolitis and bronchopneumonia. These findings strongly suggest that F. felis could be an underdiagnosed cause of feline bronchial disease.

• MeSH
• Bacteroidetes * genetika   MeSH
• chronická bronchitida mikrobiologie   veterinární   MeSH
• fylogeneze MeSH
• gramnegativní bakteriální infekce mikrobiologie   veterinární   MeSH
• kočky mikrobiologie   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• nemoci koček epidemiologie   mikrobiologie   MeSH
• plíce mikrobiologie   MeSH
• RNA ribozomální 16S genetika   MeSH
• zvířata MeSH
• Check Tag
• kočky mikrobiologie   MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Názvy látek
• RNA ribozomální 16S MeSH

Despite over a decade of cystic fibrosis (CF) microbiome research, much remains to be learned about the overall composition, metabolic activities, and pathogenicity of the microbes in CF airways, limiting our understanding of the respiratory microbiome's relation to disease. Systems-level integration and modeling of host-microbiome interactions may allow us to better define the relationships between microbiological characteristics, disease status, and treatment response. In this way, modeling could pave the way for microbiome-based development of predictive models, individualized treatment plans, and novel therapeutic approaches, potentially serving as a paradigm for approaching other chronic infections. In this review, we describe the challenges facing this effort and propose research priorities for a systems biology approach to CF lung disease.

• Klíčová slova
• cystic fibrosis, longitudinal studies, microbiome, microbiome-based therapy, predictive modeling, systems biology,
• MeSH
• Bacteria izolace a purifikace   metabolismus   MeSH
• cystická fibróza mikrobiologie   terapie   MeSH
• lidé MeSH
• mikrobiota MeSH
• plíce mikrobiologie   MeSH
• systémová biologie metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH

Pneumocystis is a genus of parasitic fungi infecting lung tissues in a wide range of mammal species, displaying a strong host specificity and patterns of co-speciation with their hosts. However, a recent study on Asiatic murids challenged these patterns reporting several Pneumocystis lineages/species shared by different host species or even genera in the Rattini and Murini tribes. Here we screened lung samples of 27 species of African rodents from five families for the presence of Pneumocystis DNA. Using reconstructed multi-locus phylogenies of both hosts and parasites, we tested the hypothesis of their co-evolution. We found that Pneumocystis is widespread in African rodents, detected in all but seven screened host species, with species-level prevalence ranging from 5.9 to 100%. Several host species carry pairs of highly divergent Pneumocystis lineages/species. The retrieved co-phylogenetic signal was highly significant (p = .0017). We found multiple co-speciations, sorting events and two host-shift events, which occurred between Murinae and Deomyinae hosts. Comparison of genetic distances suggests higher substitution rates for Pneumocystis relative to the rodent hosts on neutral loci and slower rates on selected ones. We discuss life-history traits and population dynamics factors which could explain the observed results.

• Klíčová slova
• Co-divergence, Cytochrome b, Eastern Africa, Muridae, Pneumocystis,
• MeSH
• biologická evoluce MeSH
• fylogeneze MeSH
• geny hub MeSH
• interakce hostitele a patogenu MeSH
• Muridae mikrobiologie   MeSH
• plíce mikrobiologie   MeSH
• Pneumocystis klasifikace   genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Afrika MeSH

Salmonella Typhimurium is an enteric pathogen that causes acute and chronic infections in humans and animals. One-week-old germ-free piglets were orally colonized/infected with the Salmonella Typhimurium LT2 strain or its isogenic rough ΔrfaL, ΔrfaG or ΔrfaC mutants with exactly defined lipopolysaccharide (LPS) defects. After 24 h, the piglets were euthanized and the colonization of the small intestine, translocations into the mesenteric lymph nodes, liver, spleen, lungs, and bacteremia, along with changes in the ileum histology, and transcription levels of the tight junction proteins claudin-1, claudin-2, and occludin were all assessed. Additionally, transcription levels of IL-8, TNF-α, and IL-10 in the terminal ileum, and their local and systemic protein levels were evaluated. Wild-type Salmonella Typhimurium showed the highest translocation, histopathological changes, upregulation of claudins and downregulation of occludin, transcription of the cytokines, intestinal IL-8 and TNF-α levels, and systemic TNF-α and IL-10 levels. Depending on the extent of the incompleteness of the LPS, the levels of the respective elements decreased, or no changes were observed at all in the piglets colonized/infected with Δrfa mutants. Intestinal IL-10 and systemic IL-8 levels were not detected in any piglet groups. This study provided foundational data on the gnotobiotic piglet response to colonization/infection with the exactly defined rough Salmonella Typhimurium LT2 isogenic mutants.

• Klíčová slova
• Salmonella Typhimurium, cytokines, germ-free piglet, gnotobiotic, lipopolysaccharide, tight junction proteins, Δrfa mutant,
• MeSH
• cytokiny imunologie   MeSH
• gnotobiologické modely * MeSH
• játra mikrobiologie   MeSH
• lipopolysacharidy toxicita   MeSH
• lymfatické uzliny mikrobiologie   MeSH
• mutace MeSH
• plíce mikrobiologie   MeSH
• prasata MeSH
• Salmonella typhimurium genetika   fyziologie   MeSH
• salmonelóza imunologie   mikrobiologie   patologie   MeSH
• slezina mikrobiologie   MeSH
• tenké střevo imunologie   mikrobiologie   patologie   MeSH
• virulence * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytokiny MeSH
• lipopolysacharidy MeSH

The lung in cystic fibrosis (CF) is home to numerous pathogens that shorten the lives of patients. The aim of the present study was to assess changes in the lung bacteriome following antibiotic therapy targeting Pseudomonas aeruginosa in children with CF. The study included nine children (9-18 years) with CF who were treated for their chronic or intermittent positivity for Pseudomonas aeruginosa. The bacteriomes were determined in 16 pairs of sputa collected at the beginning and at the end of a course of intravenous antibiotic therapy via deep sequencing of the variable region 4 of the 16S rRNA gene, and the total bacterial load and selected specific pathogens were assessed using quantitative real-time PCR. The effect of antipseudomonal antibiotics was observable as a profound decrease in the total 16S rDNA load (p = 0.001) as well as in a broad range of individual taxa including Staphylococcus aureus (p = 0.03) and several members of the Streptococcus mitis group (S. oralis, S. mitis, and S. infantis) (p = 0.003). Improvements in forced expiratory volume (FEV1) were associated with an increase in Granulicatella sp. (p = 0.004), whereas a negative association was noted between the total bacterial load and white blood cell count (p = 0.007). In conclusion, the data show how microbial communities differ in reaction to antipseudomonal treatment, suggesting that certain rare species may be associated with clinical parameters. Our work also demonstrates the utility of absolute quantification of bacterial load in addition to the 16S rDNA profiling.

• MeSH
• antibakteriální látky aplikace a dávkování   MeSH
• Bacteria klasifikace   účinky léků   genetika   izolace a purifikace   MeSH
• cystická fibróza farmakoterapie   mikrobiologie   MeSH
• dítě MeSH
• DNA bakterií genetika   MeSH
• lidé MeSH
• mikrobiota účinky léků   MeSH
• mladiství MeSH
• plíce mikrobiologie   MeSH
• pseudomonádové infekce farmakoterapie   mikrobiologie   MeSH
• Pseudomonas aeruginosa účinky léků   genetika   izolace a purifikace   fyziologie   MeSH
• RNA ribozomální 16S genetika   MeSH
• sputum mikrobiologie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• DNA bakterií MeSH
• RNA ribozomální 16S MeSH

Invasive pulmonary aspergillosis results in 450,000 deaths per year and complicates cancer chemotherapy, transplantations and the treatment of other immunosuppressed patients. Using a rat model of experimental aspergillosis, the fungal siderophores ferricrocin and triacetylfusarinine C were identified as markers of aspergillosis and quantified in urine, serum and lung tissues. Biomarkers were analyzed by matrix-assisted laser desorption ionization (MALDI) and electrospray ionization mass spectrometry using a 12T SolariX Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. The limits of detection of the ferri-forms of triacetylfusarinine C and ferricrocin in the rat serum were 0.28 and 0.36 ng/mL, respectively. In the rat urine the respective limits of detection achieved 0.02 and 0.03 ng/mL. In the sera of infected animals, triacetylfusarinine C was not detected but ferricrocin concentration fluctuated in the 3-32 ng/mL range. Notably, the mean concentrations of triacetylfusarinine C and ferricrocin in the rat urine were 0.37 and 0.63 μg/mL, respectively. The MALDI FTICR mass spectrometry imaging illustrated the actual microbial ferricrocin distribution in the lung tissues and resolved the false-positive results obtained by the light microscopy and histological staining. Ferricrocin and triacetylfusarinine C detection in urine represents an innovative non-invasive indication of Aspergillus infection in a host.

• MeSH
• Aspergillus chemie   metabolismus   MeSH
• aspergilóza diagnóza   mikrobiologie   MeSH
• biologické markery MeSH
• chromatografie kapalinová MeSH
• histocytochemie MeSH
• hmotnostní spektrometrie * metody   MeSH
• invazivní plicní aspergilóza diagnóza   mikrobiologie   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• metabolomika metody   MeSH
• modely nemocí na zvířatech MeSH
• plíce mikrobiologie   patologie   MeSH
• počet mikrobiálních kolonií MeSH
• siderofory analýza   chemie   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• siderofory MeSH

The interleukin 17 (IL-17) cytokine and receptor family is central to antimicrobial resistance and inflammation in the lung. Mice lacking IL-17A, IL-17F, or the IL-17RA subunit were compared with wild-type mice for susceptibility to airway inflammation in models of infection and allergy. Signaling through IL-17RA was required for efficient microbial clearance and prevention of allergy; in the absence of IL-17RA, signaling through IL-17RC on epithelial cells, predominantly by IL-17F, significantly exacerbated lower airway Aspergillus or Pseudomonas infection and allergic airway inflammation. In contrast, following infection with the upper respiratory pathogen Staphylococcus aureus, the IL-17F/IL-17RC axis mediated protection. Thus, IL-17A and IL-17F exert distinct biological effects during pulmonary infection; the IL-17F/IL-17RC signaling axis has the potential to significantly worsen pathogen-associated inflammation of the lower respiratory tract in particular, and should be investigated further as a therapeutic target for treating pathological inflammation in the lung.

• Klíčová slova
• ABPA, IL-17F/IL-17RC axis, Th17 immunity, allergy, respiratory infections,
• MeSH
• alergie genetika   imunologie   mikrobiologie   patologie   MeSH
• Aspergillus imunologie   MeSH
• aspergilóza genetika   imunologie   mikrobiologie   patologie   MeSH
• epitelové buňky imunologie   mikrobiologie   patologie   MeSH
• interleukin-17 nedostatek   genetika   imunologie   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• náchylnost k nemoci MeSH
• plíce imunologie   mikrobiologie   patologie   MeSH
• protein - isoformy nedostatek   genetika   imunologie   MeSH
• pseudomonádové infekce genetika   imunologie   mikrobiologie   patologie   MeSH
• Pseudomonas imunologie   MeSH
• receptory interleukinu-17 nedostatek   genetika   imunologie   MeSH
• regulace genové exprese MeSH
• respirační sliznice imunologie   mikrobiologie   patologie   MeSH
• signální transdukce MeSH
• stafylokokové infekce genetika   imunologie   mikrobiologie   patologie   MeSH
• Staphylococcus aureus imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Il17ra protein, mouse MeSH Prohlížeč
• interleukin-17 MeSH
• protein - isoformy MeSH
• receptory interleukinu-17 MeSH

The adenylate cyclase toxin-hemolysin (CyaA, ACT, or AC-Hly) of Bordetella pertussis targets phagocytic cells expressing the complement receptor 3 (CR3, Mac-1, αMβ2 integrin, or CD11b/CD18). CyaA delivers into cells an N-terminal adenylyl cyclase (AC) enzyme domain that is activated by cytosolic calmodulin and catalyzes unregulated conversion of cellular ATP into cyclic AMP (cAMP), a key second messenger subverting bactericidal activities of phagocytes. In parallel, the hemolysin (Hly) moiety of CyaA forms cation-selective hemolytic pores that permeabilize target cell membranes. We constructed the first B. pertussis mutant secreting a CyaA toxin having an intact capacity to deliver the AC enzyme into CD11b-expressing (CD11b+) host phagocytes but impaired in formation of cell-permeabilizing pores and defective in cAMP elevation in CD11b- cells. The nonhemolytic AC+ Hly- bacteria inhibited the antigen-presenting capacities of coincubated mouse dendritic cells in vitro and skewed their Toll-like receptor (TLR)-triggered maturation toward a tolerogenic phenotype. The AC+ Hly- mutant also infected mouse lungs as efficiently as the parental AC+ Hly+ strain. Hence, elevation of cAMP in CD11b- cells and/or the pore-forming capacity of CyaA were not required for infection of mouse airways. The latter activities were, however, involved in bacterial penetration across the epithelial layer, enhanced neutrophil influx into lung parenchyma during sublethal infections, and the exacerbated lung pathology and lethality of B. pertussis infections at higher inoculation doses (>107 CFU/mouse). The pore-forming activity of CyaA further synergized with the cAMP-elevating activity in downregulation of major histocompatibility complex class II (MHC-II) molecules on infiltrating myeloid cells, likely contributing to immune subversion of host defenses by the whooping cough agent.

• Klíčová slova
• Bordetella pertussis, adenylate cyclase toxin-hemolysin, cAMP intoxication, lung colonization, pore-forming activity, virulence,
• MeSH
• adenylátcyklasový toxin metabolismus   MeSH
• AMP cyklický metabolismus   MeSH
• antigeny CD11b metabolismus   MeSH
• Bordetella pertussis patogenita   MeSH
• buněčná membrána metabolismus   MeSH
• dendritické buňky imunologie   MeSH
• fagocyty imunologie   MeSH
• hemolyziny metabolismus   MeSH
• makrofágový antigen 1 metabolismus   MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• pertuse mikrobiologie   MeSH
• plíce mikrobiologie   patologie   MeSH
• T-lymfocyty imunologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• AMP cyklický MeSH
• antigeny CD11b MeSH
• hemolyziny MeSH
• makrofágový antigen 1 MeSH