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Journal of Applied Microbiology Feb 2019This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme...
AIMS
This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme activity against the isolates of M. bovis, M. ovis and M. bovoculi in free form and in biofilms was determined.
METHODS AND RESULTS
In this study, 54 isolates of Moraxella sp. obtained from bovine and ovine clinical samples were evaluated in vitro for capacity of biofilm formation and lysozyme susceptibility in planktonic and sessile cells. In addition, biofilms produced by four Moraxella sp. isolates were visualized under scanning electron microscope (SEM). It was possible to demonstrate, for the first time, the ability to form biofilms by M. ovis and M. bovoculi. The isolates of Moraxella sp. have the capacity to form biofilms in different intensities, varying among weak, moderate and strong. It was verified that the lysozyme shows activity on Moraxella sp. in planktonic form. However, on biofilms there was a reduction in the production, but without impairing its formation, and on consolidated biofilms the lysozyme did not have the capacity to eradicate the preformed biofilms.
CONCLUSIONS
This work shows the capacity of biofilm formation by Moraxella sp. of veterinary importance. The lysozyme susceptibility of Moraxella sp. in planktonic form shows that this enzyme has bacteriostatic activity on this micro-organism and it reduced the production of biofilms.
SIGNIFICANCE AND IMPACT OF THE STUDY
Based on the results, it is possible to infer that the biofilm formation capacity by Moraxella sp. and the resistance to lysozyme concentrations equal to or greater than the physiological levels of the ruminant tear may be linked not only to the capacity to colonize the conjunctiva, but also to remain in this place even after healing of the lesions, being a reservoir of Moraxella sp. in a herd.
Topics: Animals; Biofilms; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Moraxella bovis; Moraxellaceae Infections; Muramidase; Sheep
PubMed: 30142702
DOI: 10.1111/jam.14086 -
Zhongguo Dang Dai Er Ke Za Zhi =... Aug 2022To investigate the carriage status of () and () in preschool children and the influencing factors for the carriage status.
OBJECTIVES
To investigate the carriage status of () and () in preschool children and the influencing factors for the carriage status.
METHODS
The stratified cluster sampling method was used to select 2 031 healthy children from seven kindergartens in Shunde District of Foshan in Guangdong, China. Nasal swabs were collected from all children for the isolation and identification of and . The carriage status of and was analyzed in terms of its association with demographic features and hospital- and community-related factors.
RESULTS
The carriage rates of and were 21.81% and 52.44%, respectively among the children. The co-carriage rate of and was 14.87%. The correspondence analysis showed that the factors such as lower grade, non-local registered residence, living in rural areas, small living area, history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history were significantly associated with the co-carriage of and among the children (<0.05).
CONCLUSIONS
Co-carriage of and can be observed in preschool children. Young age, poor living environment, a history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history are important risk factors for the co-carriage of and in preschool children.
Topics: Anti-Bacterial Agents; Carrier State; Child, Preschool; Haemophilus influenzae; Humans; Infant; Moraxella catarrhalis; Nasopharynx; Respiratory Tract Infections; Skin Diseases; Streptococcus pneumoniae
PubMed: 36036125
DOI: 10.7499/j.issn.1008-8830.2204163 -
Virulence Dec 2024is a major cause of chronic obstructive pulmonary disease. Toll-like receptor 2 (TLR2) plays an important role in the inflammatory response in host respiratory...
is a major cause of chronic obstructive pulmonary disease. Toll-like receptor 2 (TLR2) plays an important role in the inflammatory response in host respiratory epithelial cells. induces an inflammatory immune response in respiratory epithelial cells that is mostly dependent on TLR2. However, the mechanisms by which this pathogen adheres to and invades the respiratory epithelium are not well understood. The present study aimed to reveal the role of TLR2 in adhesion to and invasion into alveolar epithelial cells, using molecular techniques. Pretreatment with the TLR2 inhibitor TLR2-IN-C29 enhanced adhesion to A549 cells but reduced its invasion, whereas the agonist Pam3CSK4 reduced both adhesion and invasion into A549 cells. Similarly, 73-OR strain adhesion and invasion were significantly reduced in TLR2 A549 cells. Moreover, the lung clearance rate of the 73-OR strain was significantly higher in TLR2 C57/BL6J mice than in wild-type (WT) mice. Histological analysis showed that inflammatory responses were milder in TLR2 C57/BL6J mice than in WT mice, which was confirmed by a decrease in cytokine levels in TLR2 C57/BL6J mice. Overall, these results indicate that TLR2 promoted adhesion and invasion of A549 cells and lung tissues and mediated inflammatory responses in infected lungs. This study provides important insights into the development of potential therapeutic strategies against and TLR2-induced inflammatory responses.
Topics: Animals; Mice; Alveolar Epithelial Cells; Epithelial Cells; Lung; Moraxella catarrhalis; Toll-Like Receptor 2
PubMed: 38169345
DOI: 10.1080/21505594.2023.2298548 -
The Lancet. Microbe Jul 2021Chronic obstructive pulmonary disease (COPD) is associated with airway inflammation and bacterial dysbiosis. The relationship between the airway microbiome and bronchial...
Lung microbiome composition and bronchial epithelial gene expression in patients with COPD versus healthy individuals: a bacterial 16S rRNA gene sequencing and host transcriptomic analysis.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) is associated with airway inflammation and bacterial dysbiosis. The relationship between the airway microbiome and bronchial gene expression in COPD is poorly understood. We aimed to identify differences in the airway microbiome from bronchial brushings in patients with COPD and healthy individuals and to investigate whether any distinguishing bacteria are related to bronchial gene expression.
METHODS
For this 16S rRNA gene sequencing and host transcriptomic analysis, individuals aged 45-75 years with mild-to-moderate COPD either receiving or not receiving inhaled corticosteroids and healthy individuals in the same age group were recruited as part of the Emphysema versus Airways Disease (EvA) consortium from nine centres in the UK, Germany, Italy, Poland, and Hungary. Individuals underwent clinical characterisation, spirometry, CT scans, and bronchoscopy. From bronchoscopic bronchial brush samples, we obtained the microbial profiles using 16S rRNA gene sequencing and gene expression using the RNA-Seq technique. We analysed bacterial genera relative abundance and the associations between genus abundance and clinical characteristics or between genus abundance and host lung transcriptional signals in patients with COPD versus healthy individuals, and in patients with COPD with versus without inhaled corticosteroids treatment.
FINDINGS
Between February, 2009, and March, 2012, we obtained brush samples from 574 individuals. We used 546 of 574 samples for analysis, including 207 from healthy individuals and 339 from patients with COPD (192 with inhaled corticosteroids and 147 without). The bacterial genera that most strongly distinguished patients with COPD from healthy individuals were Prevotella (median relative abundance 33·5%, IQR 14·5-49·4, in patients with COPD vs 47·7%, 31·1-60·7, in healthy individuals; p<0·0001), Streptococcus (8·6%, 3·8-15·8, vs 5·3%, 3·0-10·1; p<0·0001), and Moraxella (0·05%, 0·02-0·14, vs 0·02%, 0-0·07; p<0·0001). Prevotella abundance was inversely related to COPD severity in terms of symptoms and positively related to lung function and exercise capacity. 446 samples had assessable RNA-seq data, 257 from patients with COPD (136 with inhaled corticosteroids and 121 without) and 189 from healthy individuals. No significant associations were observed between lung transcriptional signals from bronchial brushings and abundance of bacterial genera in patients with COPD without inhaled corticosteroids treatment and in healthy individuals. In patients with COPD treated with inhaled corticosteroids, Prevotella abundance was positively associated with expression of epithelial genes involved in tight junction promotion and Moraxella abundance was associated with expression of the IL-17 and TNF inflammatory pathways.
INTERPRETATION
With increasing severity of COPD, the airway microbiome is associated with decreased abundance of Prevotella and increased abundance of Moraxella in concert with downregulation of genes promoting epithelial defence and upregulation of pro-inflammatory genes associated with inhaled corticosteroids use. Our work provides further insight in understanding the relationship between microbiome alteration and host inflammatory response, which might lead to novel therapeutic strategies for COPD.
FUNDING
EU Seventh Framework Programme, National Institute for Health Research.
Topics: Adrenal Cortex Hormones; Bacteria; Genes, rRNA; Humans; Lung; Microbiota; Moraxella; Prevotella; Pulmonary Disease, Chronic Obstructive; RNA, Ribosomal, 16S; Sputum; Transcriptome
PubMed: 35544166
DOI: 10.1016/S2666-5247(21)00035-5 -
Pediatric Pulmonology Aug 2021Pediatric flexible laryngotracheal bronchoscopy (FB) is an integral part of diagnostics and treatment at tertiary pediatric respiratory centers.
INTRODUCTION
Pediatric flexible laryngotracheal bronchoscopy (FB) is an integral part of diagnostics and treatment at tertiary pediatric respiratory centers.
AIM
FBs performed between 2013 and 2018 at our Pediatric Allergy and Respiratory Medicine Unit of the Department of Women's and Children's Health at Padua University were examined in terms of the indications, findings, and adverse events.
MATERIALS AND METHODS
The electronic medical records of pediatric patients who underwent FB at least once between 1 January 2013 and 31 December 2018 were considered. Patients' clinical data, indications for FB, anatomical findings, information derived from bronchoalveolar lavage (BAL) and bronchial brushing, and possible adverse events were analyzed.
RESULTS
There were 447 pediatric FBs performed in 428 patients (aged from 1 month to 18 years) for diagnostic purposes (92.4%), to clear secretions (3.6%), or to monitor a known condition (4.0%). The main indications were recurrent lower respiratory tract infections (LRTI, 32.2%) and chronic wet cough (9.4%). Lower airway malacia was the most common abnormal finding in these two groups (36.1% and 28.6%, respectively). BAL bacterial culture was positive in 55 children (39.6%) with recurrent LRTI and in 25 (59.5%) with chronic wet cough, being Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis the microorganisms most commonly isolated. FB proved a safe procedure and was well tolerated.
CONCLUSIONS
Pediatric FB is an essential tool at our tertiary pediatric respiratory center. It helps establish the anatomical conditions underlying several chronic respiratory conditions and any correlated microbiological findings, with a significant impact on further patient management.
Topics: Bronchoalveolar Lavage; Bronchoscopy; Child; Child Health; Female; Humans; Infant; Moraxella catarrhalis; Retrospective Studies; Women's Health
PubMed: 33969642
DOI: 10.1002/ppul.25458 -
Bacteriological Reviews Dec 1973
Review
Topics: Acinetobacter; Alcaligenes; Antigens, Bacterial; Cross Reactions; Immunodiffusion; Moraxella; Terminology as Topic
PubMed: 4203395
DOI: 10.1128/br.37.4.522-561.1973 -
Microbiology (Reading, England) Oct 2017Moraxella catarrhalis is a human-restricted opportunistic bacterial pathogen of the respiratory mucosa. It frequently colonizes the nasopharynx asymptomatically, but is... (Review)
Review
Moraxella catarrhalis is a human-restricted opportunistic bacterial pathogen of the respiratory mucosa. It frequently colonizes the nasopharynx asymptomatically, but is also an important causative agent of otitis media (OM) in children, and plays a significant role in acute exacerbations of chronic obstructive pulmonary disease (COPD) in adults. As the current treatment options for M. catarrhalis infection in OM and exacerbations of COPD are often ineffective, the development of an efficacious vaccine is warranted. However, no vaccine candidates for M. catarrhalis have progressed to clinical trials, and information regarding the distribution of M. catarrhalis virulence factors and vaccine candidates is inconsistent in the literature. It is largely unknown if virulence is associated with particular strains or subpopulations of M. catarrhalis, or if differences in clinical manifestation can be attributed to the heterogeneous expression of specific M. catarrhalis virulence factors in the circulating population. Further investigation of the distribution of M. catarrhalis virulence factors in the context of carriage and disease is required so that vaccine development may be targeted at relevant antigens that are conserved among disease-causing strains. The challenge of determining which of the proposed M. catarrhalis virulence factors are relevant to human disease is amplified by the lack of a standardized M. catarrhalis typing system to facilitate direct comparisons of worldwide isolates. Here we summarize and evaluate proposed relationships between M. catarrhalis subpopulations and specific virulence factors in the context of colonization and disease, as well as the current methods used to infer these associations.
Topics: Animals; Bacterial Proteins; Bacterial Vaccines; Humans; Moraxella catarrhalis; Moraxellaceae Infections; Otitis Media; Pulmonary Disease, Chronic Obstructive; Virulence; Virulence Factors
PubMed: 28893369
DOI: 10.1099/mic.0.000523 -
Microbiology Spectrum Jun 2022Despite distinct nasopharyngeal microbiome (NPM) profiles between asthmatics and healthy subjects, little is known about the NPM dynamics and its relation to childhood...
Despite distinct nasopharyngeal microbiome (NPM) profiles between asthmatics and healthy subjects, little is known about the NPM dynamics and its relation to childhood asthma exacerbation (AE). We investigated NPM changes by longitudinally collecting 135 flocked nasopharyngeal swabs (FNPSs) from 33 school-age asthmatic children at six time points (2 to 4-week intervals) from September to December 2017 in Hong Kong. Subjects were categorized into AE and stable asthma (AS) groups according to whether they experienced any exacerbation during follow-up. One-off FNPSs from nine nonasthmatic children were included as controls. Microbiota profiles were analyzed using 16S rRNA gene sequencing. All 144 NPMs were classified into six microbiome profile groups (MPGs), each dominated by , , , Staphylococcus, Streptococcus, or . The microbial diversity and compositions of NPM in exacerbation samples were different from both baseline samples and those from healthy controls. and -dominated NPM exhibited high temporal stability revealed by MPG transition analysis. NPM diversity decreased whereas microbial composition remained similar over time. The relative abundances of increased while , , and Pseudomonas decreased longitudinally. However, these temporal patterns did not differ between AE and AS groups, suggesting that short-term dynamic patterns were not sufficient to predict AE occurrence. Asthmatic NPM underwent expansion during AE and presented a high microbiome resilience (recovery potential) after AE resolution. Microbial pathways involved in methane, ketone bodies, and vitamin B3 metabolisms were enhanced during AE and primarily contributed by . Evidence on the dynamic changes of NPM in asthmatic patients remains limited. Here, we present that asthmatic NPMs deviating from a healthy status still showed resilience after disturbance. Our data imply from a longitudinal perspective that increase is closely related to AE occurrence. The finding of functional dysbiosis (imbalance) during AE offers a plausible explanation for the known association between nasopharyngeal expansion and increased AE risk. This work serves as a basis for future long-term prospective studies leveraging multiomics approaches to elucidate the temporal association between NPM and pediatric AE.
Topics: Asthma; Child; Corynebacterium; Humans; Microbiota; Moraxella; Nasopharynx; Prospective Studies; RNA, Ribosomal, 16S
PubMed: 35546575
DOI: 10.1128/spectrum.00129-22 -
Human Vaccines & Immunotherapeutics Dec 2023A candidate AS01-adjuvanted vaccine containing four surface proteins from non-typable and (NTHi-Mcat) has been developed to help prevent exacerbations of chronic... (Randomized Controlled Trial)
Randomized Controlled Trial
Immunogenicity and safety of the non-typable - (NTHi-Mcat) vaccine administered following the recombinant zoster vaccine versus administration alone: Results from a randomized, phase 2a, non-inferiority trial.
A candidate AS01-adjuvanted vaccine containing four surface proteins from non-typable and (NTHi-Mcat) has been developed to help prevent exacerbations of chronic obstructive pulmonary disease (COPD). Sequential administration of different vaccines containing the same AS01-adjuvant system could lead to immune interference. We compared administration of NTHi-Mcat following AS01-adjuvanted recombinant zoster vaccine (RZV) versus NTHi-Mcat alone. This phase 2a, open-label trial (NCT03894969) randomized healthy current or former smokers (50-80 years) without COPD to administration of NTHi-Mcat at 1, 3 or 6 months after RZV or to NTHi-Mcat alone (2-dose for both vaccines). Primary outcome was non-inferiority of the humoral immune response to NTHi-Mcat administered 1 month after RZV versus NTHi-Mcat alone, evaluated by specific antibody geometric mean concentration (GMC) ratio with 95% confidence intervals (CIs). The per-protocol set included 411 participants. Primary objective was met; lower limit of the 95%CI for the GMC ratio above 0.667 for all four vaccine antigens, 1 month after the second NTHi-Mcat dose. NTHi-Mcat induced similar immune response regardless of whether administered alone or 1, 3 or 6 months following RZV. Safety and reactogenicity profiles were acceptable; adverse event frequency was similar among study groups. Injection site pain was the most common symptom. No new safety concerns were identified. The study demonstrated non-inferiority of the immune response elicited by NTHi-Mcat administered sequentially to RZV versus NTHi-Mcat alone, indicating no immune interference. Starting from 1 month, no specific interval is required between RZV and NTHi-Mcat containing the same AS01-adjuvant system components in different quantities.
Topics: Humans; Haemophilus influenzae; Herpes Zoster; Herpes Zoster Vaccine; Immunogenicity, Vaccine; Moraxella catarrhalis; Pulmonary Disease, Chronic Obstructive; Vaccines, Synthetic
PubMed: 36974988
DOI: 10.1080/21645515.2023.2187194 -
Carbohydrate Research Feb 2024Moraxella ovis is a Gram-negative bacterium isolated from sheep conjunctivitis cases and is a rare isolate of infectious bovine keratoconjunctivitis (IBK). This species...
Moraxella ovis is a Gram-negative bacterium isolated from sheep conjunctivitis cases and is a rare isolate of infectious bovine keratoconjunctivitis (IBK). This species is closely related to M. bovoculi, another species which can also be isolated from IBK, or cattle upper respiratory tract (URT). Prior to molecular identification techniques, M. bovoculi was frequently misclassified as M. ovis. We previously described the structure of two oligosaccharides (lipooligosaccharide-derived, minor and major glycoforms) from M. bovoculi 237T (type strain, also ATCC BAA-1259T). Here, we have identified the genetic loci for lipooligosaccharide synthesis in M. ovis 354T (NCTC11227) and compared it with M. bovoculi 237T. We identified genes encoding the known glycosyltransferases Lgt6 and Lgt3 in M.ovis. These genes are conserved in Moraxella spp., including M bovoculi. We identified three further putative OS biosynthesis genes that are restricted to M. ovis and M. bovoculi. These encode enzymes predicted to function as GDP-mannose synthases, namely a mannosyltransferase and a glycosyltransferase. Adding insight into the genetic relatedness of M.ovis and M. bovoculi, the M. ovis genes have higher similarity to those in M. bovoculi genotype 2 (nasopharyngeal isolates from asymptomatic cattle), than to M. bovoculi genotype 1 (isolates from eyes of IBK-affected cattle). Sequence analysis confirmed that the predicted mannosyltransferase in M. bovoculi 237T is interrupted by a C>T polymorphism. This mutation is not present in other M. bovoculi strains sequenced to date. We isolated and characterised LOS-derived oligosaccharide from M. ovis 354T. GLC-MS and NMR spectroscopy data revealed a heptasaccharide structure with three β-D-Glcp residues attached as branches to the central 3,4,6-α-D-Glcp, with subsequent attachment to Kdo. This inner core arrangement is consistent with the action of Lgt6 and Lgt3 glycosyltransferases. Two α-D-Manp residues are linearly attached to the 4-linked β-D-Glcp, consistent with the presence of the two identified glycosyltransferases. This oligosaccharide structure is consistent with the previously reported minor glycoform isolated from M. bovoculi 237T.
Topics: Animals; Cattle; Sheep; Mannosyltransferases; Keratoconjunctivitis, Infectious; Moraxella; Glycosyltransferases; Oligosaccharides; Lipopolysaccharides
PubMed: 38281396
DOI: 10.1016/j.carres.2024.109043