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Carbohydrate Research Apr 2024Moraxella nonliquefaciens is a commensal of the human upper respiratory tract (URT) but on rare occasions is recovered in cases of ocular, septic and pulmonary...
Moraxella nonliquefaciens is a commensal of the human upper respiratory tract (URT) but on rare occasions is recovered in cases of ocular, septic and pulmonary infections. Hence there is interest in the pathogenic determinants of M. nonliquefaciens, of which outer membrane (OM) structures such as fimbriae and two capsular polysaccharide (CPS) structures, →3)-β-D-GalpNAc-(1→5)-β-Kdop-(2→ and →8)-α-NeuAc-(2→, have been reported in the literature. To further characterise its surface virulence factors, we isolated a novel CPS from M. nonliquefaciens type strain CCUG 348T. This structure was elucidated using NMR data obtained from CPS samples that were subjected to various degrees of mild acid hydrolysis. Together with GLC-MS data, the structure was resolved as a linear polymer composed of two GalfNAc residues consecutively added to Kdo, →3)-β-D-GalfNAc-(1→3)-α-D-GalfNAc-(1→5)-α-(8-OAc)Kdop-(2→. Supporting evidence for this material being CPS was drawn from the proposed CPS biosynthetic locus which encoded a potential GalfNAc transferase, a UDP-GalpNAc mutase for UDP-GalfNAc production and a putative CPS polymerase with predicted GalfNAc and Kdo transferase domains. This study describes a unique CPS composition reported in Moraxella spp. and offers genetic insights into the synthesis and expression of GalfNAc residues, which are rare in bacterial OM glycans.
Topics: Humans; Polysaccharides; Moraxella; Transferases; Uridine Diphosphate; Bacterial Capsules; Polysaccharides, Bacterial
PubMed: 38507941
DOI: 10.1016/j.carres.2024.109095 -
Vestnik Otorinolaringologii 2024Children's and adults' rhinosinusitis are two diseases that have both similarities and differences in anatomy, epidemiology, causes, pathogenesis, diagnosis and...
Children's and adults' rhinosinusitis are two diseases that have both similarities and differences in anatomy, epidemiology, causes, pathogenesis, diagnosis and treatment. At the same rhinosinusitis is one of the most common in otorhinolaryngology's practice, both in children and adults. The of adults paranasal sinuses (PNS) anatomy differs from children's PNS anatomy. Although ostiomeatal complex occlusion is recognized as a major cause of poor ventilation and drainage of the adult paranasal sinuses, it does not have a strong effect on pediatric rhinosinusitis, but adenoids play a key role. Adenoids are bacteria and biofilms reservoirs that cause chronic refractory rhinosinusitis regardless of pharyngeal tonsil size. The prevalence of chronic rhinosinusitis (CRS) is lower in children than in adults. Diagnosis of children's rhinosinusitis is more difficult because nasal cavity endoscopic examination is performed rarely due to the occasional need of general anesthesia during the procedure. Moreover, it's necessary to take into account prevailing etiological role of viruses in ARS at children's age and chronic adenoiditis often accompanies pediatric CRS, which requires attention prescribing medical therapy as the basis of rhinosinusitis treatment. The DysheLORz based on roots is highly effective and safe for children's and adults ARS and CRS treatment, both as monotherapy and in combination with topical steroids and antibiotics. This herbal medicine immunomodulatory effect is mediated mainly by stimulating the production of TNF-α, IL-1, IL-12 and IFN-γ. It activates macrophages and improves their phagocytic activity. IL-12, together with TNF-α, enhances NK and cytotoxic CD8 lymphocytes' activity against infected cells. IL-12 effect on Th1 lymphocytes maturation provides a link between innate and adaptive immunity. This is also increasing MCP-1, IP-10 and MIP-1β chemokines synthesis and decreasing MIP-1α, ENA-78, GROα and IL-8 production in PNS and nasal mucosa. This leads to decrease of neutrophils chemotaxis to the inflammation site, and decline of serine proteases concentration (neutrophils main enzymes), that increases mucous membrane epithelial barrier permeability, reducing bacterial infections risk. Additionally, increases epithelial cells beating cilia frequency and inhibits hemagglutinin and neuraminidase present on influenza virus surface. The drug increases antimicrobial peptides production as defensins, human neutrophil peptides (HNP) and bactericidal permeability-increasing protein (BPI), which is also important for rapid inflammation regression in rhinosinusitis. It causes bacterial adhesion to epithelial cells inhibition, phagocytosis stimulation, nitric oxide (NO) release and oxidative burst. The medicine had a direct effect on and . Based on these data, it is possible to explain the high effectiveness and safety of the drugs based on in ENT organs inflammation treatment, for both adults and children over 1 year old.
Topics: Adult; Humans; Child; Infant; Rhinitis; Rhinosinusitis; Tumor Necrosis Factor-alpha; Sinusitis; Nasal Mucosa; Inflammation; Interleukin-12; Chronic Disease
PubMed: 38506028
DOI: 10.17116/otorino20248901164 -
The Journal of Asthma : Official... Mar 2024In a previous study we have shown that, in the presence of interleukin (IL)-33, repeated, per-nasal challenge of murine airways with () organisms induces human...
In a previous study we have shown that, in the presence of interleukin (IL)-33, repeated, per-nasal challenge of murine airways with () organisms induces human asthma-like airways inflammation. It is not clear, however, whether this effect is unique or manifest in response to other common respiratory pathogens. To explore this, airways of BALB/c mice were repeatedly challenged per-nasally with formaldehyde-inactivated bacterial bodies in the presence or absence of murine recombinant IL-33. Serum concentrations of , () and () lysates-specific IgE were measured in patients with asthma and control subjects. We showed that in the presence of IL-33, repeated, per-nasal airways exposure to the bodies of these bacteria induced airways hyperresponsiveness (AHR) in the experimental mice. This was accompanied by cellular infiltration into bronchoalveolar lavage fluid (BALF), eosinophilic infiltration and mucous hypertrophy of the lung tissue, with elevated local expression of some type 2 cytokines and elevated, specific IgG and IgE in the serum. The precise characteristics of the inflammation evoked by exposure to each bacterial species were distinguishable. These results suggest that in the certain circumstances, inhaled or commensal bacterial body antigens of both Gram-positive () and Gram-negative ( and ) respiratory tract bacteria may initiate type 2 inflammation typical of asthma in the airways. In addition, we demonstrated that human asthmatic patients manifest elevated serum concentrations of and specific IgE.
PubMed: 38478043
DOI: 10.1080/02770903.2024.2330063 -
Frontiers in Public Health 2024This study aimed to investigate the epidemiological characteristics of common pathogens contributing to childhood lower respiratory tract infections (LRTIs) in Xiangtan...
OBJECTIVE
This study aimed to investigate the epidemiological characteristics of common pathogens contributing to childhood lower respiratory tract infections (LRTIs) in Xiangtan City, Hunan Province before and during the coronavirus disease 2019 (COVID-19) pandemic.
METHODS
A total of 11,891 enrolled patients, aged 1 month to 14 years, diagnosed with LRTIs and admitted to Xiangtan Central Hospital from January 2018 to December 2021 were retrospectively reviewed in this study. Specifically, the epidemiological characteristics of these pathogens before and during the COVID-19 pandemic were analyzed.
RESULTS
There was a significant decrease in the number of children hospitalized with LRTIs during the COVID-19 pandemic (2020-2021) compared to data from 2018 to 2019 (before the COVID-19 pandemic). Of these cases, 60.01% (7,136/11,891) were male and 39.99% (4,755/11,891) were female. 78.9% (9,381/11,891) cases occurred in children under 4 years of age. The average pathogen detection rate among 11,891 hospitalized LRTIs children was 62.19% (7,395/11,891), with the average pathogen detection rate of 60.33% (4,635/7,682) and 65.57% (2,670/4,209) before and during COVID-19 pandemic, respectively. The detection rates of adenovirus (ADV), (BP) and () decreased dramatically, while the detection rates of influenza viruses (IFV), parainfluenza viruses (PIV), respiratory syncytial virus (RSV), (), (), and () increased significantly during the COVID-19 pandemic. Overall, RSV, (MP), , and IFV were the major pathogens causing LRTIs in hospitalized children before and during the COVID-19 pandemic.
CONCLUSION
Public health interventions for COVID-19 prevention are beneficial to reduce the incidence of LRTIs in children by limiting the prevalence of ADV, MP, BP, and , but which have limited restrictive effects on other common LRTIs-associated pathogens. Collectively, the data in this study comprehensively investigated the effects of COVID-19 pandemic on the epidemiological characteristics of respiratory pathogens, which will be beneficial for improving early preventive measures.
Topics: Child; Humans; Male; Female; Child, Preschool; Child, Hospitalized; Retrospective Studies; Staphylococcus aureus; Pandemics; COVID-19; Respiratory Tract Infections; Respiratory Syncytial Viruses
PubMed: 38476493
DOI: 10.3389/fpubh.2024.1367614 -
Foods (Basel, Switzerland) Mar 2024To expound on the correlation between the microorganism communities and the formation of off-odour in Xuanwei ham, the microorganism communities and volatile compounds...
To expound on the correlation between the microorganism communities and the formation of off-odour in Xuanwei ham, the microorganism communities and volatile compounds were investigated in the biceps femoris (BF) and semimembranosus (SM) of Xuanwei ham with different quality grades (normal ham and spoiled ham). The single molecule real-time sequencing showed that differential bacteria and fungi were more varied in normal hams than in spoiled hams. Headspace solid-phase microextraction-gas chromatography (HS-SPME-GC-MS) results indicated that aldehydes and alcohols were significantly higher in spoiled hams than those in normal hams ( < 0.05). The off-odour of spoiled hams was dominated by ichthyic, malodourous, sweaty, putrid, sour, and unpleasant odours produced by compounds such as trimethylamine (SM: 13.05 μg/kg), hexanal (BF: 206.46 μg/kg), octanal (BF: 59.52 μg/kg), methanethiol (SM: 12.85 μg/kg), and valeric acid (BF: 15.08 μg/kg), which are positively correlated with , , , sp., , and . Furthermore, the physicochemical property and quality characteristics results showed that high moisture (BF: 56.32 g/100 g), pH (BF: 6.63), thiobarbituric acid reactive substances (TBARS) (SM: 1.98 MDA/kg), and low NaCl content (SM: 6.31%) were also responsible for the spoilage of hams with off-odour. This study provided a deep insight into the off-odour of Xuanwei ham from the perspective of microorganism communities and a theoretical basis for improving the flavour and overall quality of Xuanwei hams.
PubMed: 38472889
DOI: 10.3390/foods13050776 -
The Journal of Allergy and Clinical... Jun 2024The respiratory microbiome has been associated with the etiology and disease course of asthma.
BACKGROUND
The respiratory microbiome has been associated with the etiology and disease course of asthma.
OBJECTIVE
We sought to assess the nasopharyngeal microbiota in children with a severe asthma exacerbation and their associations with medication, air quality, and viral infection.
METHODS
A cross-sectional study was performed among children aged 2 to 18 years admitted to the medium care unit (MCU; n = 84) or intensive care unit (ICU; n = 78) with an asthma exacerbation. For case-control analyses, we matched all cases aged 2 to 6 years (n = 87) to controls in a 1:2 ratio. Controls were participants of either a prospective case-control study or a longitudinal birth cohort (n = 182). The nasopharyngeal microbiota was characterized by 16S-rRNA-gene sequencing.
RESULTS
Cases showed higher Shannon diversity index (ICU and MCU combined; P = .002) and a distinct microbial community composition when compared with controls (permutational multivariate ANOVA R = 1.9%; P < .001). We observed significantly higher abundance of Staphylococcus and "oral" taxa, including Neisseria, Veillonella, and Streptococcus spp. and a lower abundance of Dolosigranulum pigrum, Corynebacterium, and Moraxella spp. (MaAsLin2; q < 0.25) in cases versus controls. Furthermore, Neisseria abundance was associated with more severe disease (ICU vs MCU MaAslin2, P = .03; q = 0.30). Neisseria spp. abundance was also related with fine particulate matter exposure, whereas Haemophilus and Streptococcus abundances were related with recent inhaled corticosteroid use. We observed no correlations with viral infection.
CONCLUSIONS
Our results demonstrate that children admitted with asthma exacerbations harbor a microbiome characterized by overgrowth of Staphylococcus and "oral" microbes and an underrepresentation of beneficial niche-appropriate commensals. Several of these associations may be explained by (environmental or medical) exposures, although cause-consequence relationships remain unclear and require further investigations.
Topics: Humans; Asthma; Child; Child, Preschool; Male; Nasopharynx; Female; Microbiota; Adolescent; Cross-Sectional Studies; Case-Control Studies; RNA, Ribosomal, 16S; Disease Progression; Prospective Studies; Bacteria
PubMed: 38467291
DOI: 10.1016/j.jaci.2024.02.020 -
Frontiers in Epidemiology 2023COVID-19 has emerged as a highly contagious and debilitating disease caused by the SARS-CoV-2 virus and has claimed the lives of over 7.7 million people worldwide....
INTRODUCTION
COVID-19 has emerged as a highly contagious and debilitating disease caused by the SARS-CoV-2 virus and has claimed the lives of over 7.7 million people worldwide. Bacterial co-infections are one of many co-morbidities that have been suggested to impact the outcome of COVID-19 in patients. The goals of this study are to elucidate the presence of bacteria in the nasopharynx of SARS-CoV-2 positive and negative patients and to describe demographic categories that may be associated with the detection of these organisms during one of the initial waves of the COVID-19 pandemic.
METHODS
To this end, we investigated SARS-CoV-2 and bacterial co-detection from outpatient RT-PCR testing in Texas.
RESULTS
The results indicate that , , , , and were the most frequently detected bacteria in both SARS-CoV-2 positive and SARS-CoV-2 negative patients and that these bacteria were present in these two patient populations at similar proportions. We also detected in a significantly larger proportion of males relative to females and people under 65 years of age relative to those 65 and over. Finally, we observed that SARS-CoV-2 was more commonly detected in Hispanics compared to non-Hispanics; however, low disclosure rates make volunteer bias a concern when interpreting the effects of demographic variables.
DISCUSSION
This study describes the bacteria present in the nasopharynx of SARS-CoV-2 positive and negative patients, highlights associations between patient demographics and SARS-CoV-2 as well as bacterial co-detection. In addition, this study highlights RT-PCR based molecular testing as a tool to detect bacteria simultaneously when SARS-CoV-2 tests are performed.
PubMed: 38455907
DOI: 10.3389/fepid.2023.1274800 -
Environmental Research Jun 2024Plastic waste has become a global issue and a threat to the ecosystem. The present study isolated polyurethane (PU) degrading bacterial species from soil dumped with...
Plastic waste has become a global issue and a threat to the ecosystem. The present study isolated polyurethane (PU) degrading bacterial species from soil dumped with plastic wastes. Four bacterial isolates, RS1, RS6, RS9 and RS13 were obtained and their ability to degrade PU in a synthetic medium with PU as a sole source of carbon was assessed individually. After thirty days of incubation, the highest PU weight loss of 67.36 ± 0.32% was recorded in the medium containing RS13 isolate. The results of FTIR revealed the occurrence of carbonyl peaks. The putative isolate RS13 confirmed with the genus Moraxella according to 16S rRNA gene sequencing and the isolate was specified as Moraxella catarrhalis strain BMPPS3. The restriction analysis of Moraxella catarrhalis strain BMPPS3 revealed that the GCAT content to 51% and 49% correspondingly. Moraxella catarrhalis strain BMPPS3 was able to colonize on PU surface and form a biofilm as revealed by SEM investigation. Fatty acids and alkanes were found to be the degradation products by GC-MS analysis. The presence of these metabolites facilitated the growth of strain RS13 and suggested that ester hydrolysis products had been mineralized into CO and HO. Extracellular biosurfactant synthesis has also been found in Moraxella catarrhalis strain BMPPS13 inoculated with synthetic media and mineral salt media containing PU and glucose as carbon sources, respectively with a significant level of cell-surface hydrophobicity (32%). The production and activity of extracellular esterase showed consistent increase from day 1-15 which peaked (1.029 mM/min/mg) on day 24 significantly at P < 0.001. Crude biosurfactants were lipopeptide-based, according to the characteristic investigation. According to this study findings, Moraxella catarrhalis produces biosurfactants of the esterase, urethanase and lipase (lipopeptide) types when carbon source PU is present.
Topics: Polyurethanes; Moraxella catarrhalis; Biodegradation, Environmental; Soil Microbiology; RNA, Ribosomal, 16S; Biofilms
PubMed: 38452914
DOI: 10.1016/j.envres.2024.118631 -
Medical Microbiology and Immunology Mar 2024Multidrug-resistant clinical isolates of Moraxella catarrhalis have emerged, increasing the demand for the identification of new treatment and prevention strategies. A...
Multidrug-resistant clinical isolates of Moraxella catarrhalis have emerged, increasing the demand for the identification of new treatment and prevention strategies. A thorough understanding of how M. catarrhalis can establish an infection and respond to different stressors encountered in the host is crucial for new drug-target identification. Formaldehyde is a highly cytotoxic compound that can be produced endogenously as a by-product of metabolism and exogenously from environmental sources. Pathways responsible for formaldehyde detoxification are thus essential and are found in all domains of life. The current work investigated the role of the system consisting of the S-hydroxymethyl alcohol dehydrogenase (AdhC), a Zn-dependent class III alcohol dehydrogenase, and the S-formyl glutathione hydrolase (FghA) in the formaldehyde detoxification process in M. catarrhalis. Bioinformatics showed that the components of the system are conserved across the species and are highly similar to those of Streptococcus pneumoniae, which share the same biological niche. Isogenic mutants were constructed to study the function of the system in M. catarrhalis. A single fghA knockout mutant did not confer sensitivity to formaldehyde, while the adhC-fghA double mutant is formaldehyde-sensitive. In addition, both mutants were significantly cleared in a murine pulmonary model of infection as compared to the wild type, demonstrating the system's importance for this pathogen's virulence. The respective phenotypes were reversed upon the genetic complementation of the mutants. To date, this is the first study investigating the role of the AdhC-FghA system in formaldehyde detoxification and pathogenesis of M. catarrhalis.
Topics: Animals; Mice; Moraxella catarrhalis; Streptococcus pneumoniae; Formaldehyde; Glutathione; Hydrolases
PubMed: 38448747
DOI: 10.1007/s00430-024-00785-0 -
Pediatric Allergy and Immunology :... Mar 2024Wheezing is the cardinal symptom of asthma; its presence early in life, mostly caused by viral infections, is a major risk factor for the establishment of persistent or... (Review)
Review
Wheezing is the cardinal symptom of asthma; its presence early in life, mostly caused by viral infections, is a major risk factor for the establishment of persistent or recurrent disease. Early-life wheezing and asthma exacerbations are triggered by common respiratory viruses, mainly rhinoviruses (RV), and to a lesser extent, respiratory syncytial virus, parainfluenza, human metapneumovirus, coronaviruses, adenoviruses, influenza, and bocavirus. The excess presence of bacteria, several of which are part of the microbiome, has also been identified in association with wheezing and acute asthma exacerbations, including haemophilus influenza, streptococcus pneumoniae, moraxella catarrhalis, mycoplasma pneumoniae, and chlamydophila pneumonia. While it is not clear when asthma starts, its characteristics develop over time. Airway remodeling already appears between the ages of 1 and 3 years of age even prior to the presence of atopic inflammation or an asthma diagnosis. The role of genetic defect or variations hampering the airway epithelium in response to environmental stimuli and severe disease morbidity are now considered as major determinants for early structural changes. Repeated viral infections can induce and perpetuate airway hyperresponsiveness. Allergic sensitization, that often precedes infection-induced wheezing, shifts inflammation toward type-2, while common respiratory infections themselves promote type-2 inflammation. Nevertheless, most children who wheeze with viral infections during infancy and during preschool years do not develop persistent asthma. Multiple factors, including illness severity, viral etiology, allergic sensitization, and the exposome, are associated with disease persistence. Here, we summarize current knowledge and developments in infection epidemiology of asthma in children, describing the known impact of each individual agent and mechanisms of transition from recurrent wheeze to asthma.
Topics: Child; Child, Preschool; Humans; Infant; Influenza, Human; Respiratory Sounds; Asthma; Bacteria; Respiratory Syncytial Viruses; Inflammation
PubMed: 38445451
DOI: 10.1111/pai.14098