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Frontiers in Immunology 2024Bronchiolitis, a viral lower respiratory infection, is the leading cause of infant hospitalization, which is associated with an increased risk for developing asthma...
Bronchiolitis, a viral lower respiratory infection, is the leading cause of infant hospitalization, which is associated with an increased risk for developing asthma later in life. Bronchiolitis can be caused by several respiratory viruses, such as respiratory syncytial virus (RSV), rhinovirus (RV), and others. It can also be caused by a solo infection (e.g., RSV- or RV-only bronchiolitis) or co-infection with two or more viruses. Studies have shown viral etiology-related differences between RSV- and RV-only bronchiolitis in the immune response, human microRNA (miRNA) profiles, and dominance of certain airway microbiome constituents. Here, we identified bacterial small RNAs (sRNAs), the prokaryotic equivalent to eukaryotic miRNAs, that differ between infants of the 35 Multicenter Airway Research Collaboration (MARC-35) cohort with RSV- versus RV-only bronchiolitis. We first derived reference sRNA datasets from cultures of four bacteria known to be associated with bronchiolitis (i.e., , , , and ). Using these reference sRNA datasets, we found several sRNAs associated with RSV- and RV-only bronchiolitis in our human nasal RNA-Seq MARC-35 data. We also determined potential human transcript targets of the bacterial sRNAs and compared expression of the sRNAs between RSV- and RV-only cases. sRNAs are known to downregulate their mRNA target, we found that, compared to those associated with RV-only bronchiolitis, sRNAs associated with RSV-only bronchiolitis may relatively activate the IL-6 and IL-8 pathways and relatively inhibit the IL-17A pathway. These data support that bacteria may be contributing to inflammation differences seen in RSV- and RV-only bronchiolitis, and for the first time indicate that the potential mechanism in doing so may be through bacterial sRNAs.
Topics: Infant; Humans; Rhinovirus; RNA, Bacterial; Bronchiolitis; Respiratory Syncytial Virus, Human; Respiratory Syncytial Virus Infections; Viruses; MicroRNAs; Enterovirus Infections; Immunity
PubMed: 38410509
DOI: 10.3389/fimmu.2024.1330991 -
Revista Argentina de Microbiologia 2024Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that affects bovines and has significant economic and health effects worldwide. Gram negative bacteria...
Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that affects bovines and has significant economic and health effects worldwide. Gram negative bacteria Moraxella bovis and Moraxella bovoculi are its main etiological agents. Antimicrobial therapy against IBK is often difficult in beef and dairy herds and, although vaccines are commercially available, their efficacy is variable and dependent on local strains. The aim of this study was to analyze for the first time the genomes of Uruguayan clinical isolates of M. bovis and M. bovoculi. The genomes were de novo assembled and annotated; the genetic basis of fimbrial synthesis was analyzed and virulence factors were identified. A 94% coverage in the reference genomes of both species, and more than 80% similarity to the reference genomes were observed. The mechanism of fimbrial phase variation in M. bovis was detected, and the tfpQ orientation of these genes confirmed, in an inversion region of approximately 2.18kb. No phase variation was determined in the fimbrial gene of M. bovoculi. When virulence factors were compared between strains, it was observed that fimbrial genes have 36.2% sequence similarity. In contrast, the TonB-dependent lactoferrin/transferrin receptor exhibited the highest percentage of amino acid similarity (97.7%) between strains, followed by cytotoxins MbxA/MbvA and the ferric uptake regulator. The role of these virulence factors in the pathogenesis of IBK and their potential as vaccine components should be explored.
Topics: Animals; Moraxella; Cattle; Moraxella bovis; Keratoconjunctivitis, Infectious; Cattle Diseases; Genome, Bacterial; Moraxellaceae Infections; Uruguay; Virulence Factors
PubMed: 38403533
DOI: 10.1016/j.ram.2023.12.003 -
Vaccines Feb 2024Chronic obstructive pulmonary disease (COPD) is a frequent, often progressive, chronic disease of the lungs. Patients with COPD often have impaired immunity; therefore,... (Review)
Review
Chronic obstructive pulmonary disease (COPD) is a frequent, often progressive, chronic disease of the lungs. Patients with COPD often have impaired immunity; therefore, they are prone to chest infections, such as pneumonia or bronchitis. Acute exacerbations of COPD are major events that accelerate disease progression, contributing to its symptoms' burden, morbidity, and mortality. Both pneumonia and acute exacerbations in COPD are caused by bacteria against which there are effective vaccinations. Although the number of randomised controlled studies on bacterial vaccinations in COPD is limited, national and international guidelines endorse specific vaccinations in patients with COPD. This review will summarise the different types of vaccinations that prevent pneumonia and COPD exacerbations. We also discuss the results of early phase studies. We will mainly focus on , as this bacterium was predominantly investigated in COPD. However, we also review studies investigating vaccinations against , , and .
PubMed: 38400196
DOI: 10.3390/vaccines12020213 -
Microorganisms Jan 2024, a commensal in the human nasopharynx, plays a significant role in the acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Its pathogenicity involves...
, a commensal in the human nasopharynx, plays a significant role in the acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Its pathogenicity involves adherence to respiratory epithelial cells, leading to infection through a macropinocytosis-like mechanism. Previous investigations highlighted the diverse abilities of isolates with different phenotypes to adhere to and invade respiratory epithelial cells. This study used a murine COPD model and in vitro experiments to explore the factors influencing the pathogenicity of distinct phenotypes of . Transcriptome sequencing suggested a potential association between actin cytoskeleton regulation and the infection of lung epithelial cells by with different phenotypes. Electron microscopy and Western blot analyses revealed a decrease in filamentous actin (F-actin) expression upon infection with various phenotypes. Inhibition of actin polymerization indicated the involvement of F-actin dynamics in internalization, distinguishing it from the adhesion process. Notably, hindering F-actin polymerization impaired the internalization of . These findings contribute vital theoretical insights for developing preventive strategies and individualized clinical treatments for AECOPD patients infected with . The study underscores the importance of understanding the nuanced interactions between phenotypes and host lung epithelial cells, offering valuable implications for the management of AECOPD infections.
PubMed: 38399695
DOI: 10.3390/microorganisms12020291 -
Antibiotics (Basel, Switzerland) Feb 2024The impact of bacterial pneumonia on patients with COVID-19 infection remains unclear. This prospective observational monocentric cohort study aims to determine the...
The impact of bacterial pneumonia on patients with COVID-19 infection remains unclear. This prospective observational monocentric cohort study aims to determine the incidence of bacterial community- and hospital-acquired pneumonia (CAP and HAP) and its effect on mortality in critically ill COVID-19 patients admitted to the intensive care unit (ICU) at University Hospital Olomouc between 1 November 2020 and 31 December 2022. The secondary objectives of this study include identifying the bacterial etiology of CAP and HAP and exploring the capabilities of diagnostic tools, with a focus on inflammatory biomarkers. Data were collected from the electronic information hospital system, encompassing biomarkers, microbiological findings, and daily visit records, and subsequently evaluated by ICU physicians and clinical microbiologists. Out of 171 patients suffering from critical COVID-19, 46 (27%) had CAP, while 78 (46%) developed HAP. Critically ill COVID-19 patients who experienced bacterial CAP and HAP exhibited higher mortality compared to COVID-19 patients without any bacterial infection, with rates of 38% and 56% versus 11%, respectively. In CAP, the most frequent causative agents were chlamydophila and mycoplasma; Enterobacterales, which were multidrug-resistant in 71% of cases; Gram-negative non-fermenting rods; and . Notably, no strains of were detected, and only a single strain each of and was isolated. The most frequent etiologic agents causing HAP were Enterobacterales and Gram-negative non-fermenting rods. Based on the presented results, commonly used biochemical markers demonstrated poor predictive and diagnostic accuracy. To confirm the diagnosis of bacterial CAP in our patient cohort, it was necessary to assess the initial values of inflammatory markers (particularly procalcitonin), consider clinical signs indicative of bacterial infection, and/or rely on positive microbiological findings. For HAP diagnostics, it was appropriate to conduct regular detailed clinical examinations (with a focus on evaluating respiratory functions) and closely monitor the dynamics of inflammatory markers (preferably Interleukin-6).
PubMed: 38391578
DOI: 10.3390/antibiotics13020192 -
Revista Cientifica Odontologica... 2023To describe the existing knowledge about the alterations of the MBO oral microbiome and the presence of OL Oral Lesions in patients with Acute Lymphoblastic Leukemia ALL. (Review)
Review
OBJECTIVE
To describe the existing knowledge about the alterations of the MBO oral microbiome and the presence of OL Oral Lesions in patients with Acute Lymphoblastic Leukemia ALL.
MATERIALS AND METHODS
An electronic search was carried out in the PubMed, SciELO, and academic Google databases, and descriptive, analytical, observational articles on MBO, OL, and ALL were included, following the PRISMA criteria. 642 were evaluated, duplicate articles, case reports, and those where only changes were reported during or after chemotherapy treatment were eliminated.
RESULTS
10 articles were evaluated, published between 1997 and 2021, 4 articles agreed that the MBO of patients with ALL is in dysbiosis showing a significant increase in firmicutes 0.1%, bacillus 0.05%, and opportunistic bacteria such as , 5.66%, 3.77%, 1.88%, 1.88% and 1.08%, the most frequent OL reported in 5 articles were spontaneous gingival bleeding 3.5%, gingivitis 25% and ulcers 9.4%.
CONCLUSIONS
The oral cavity of patients with ALL is in dysbiosis and associated OL is identified. It is necessary to establish preventive strategies with a niche-ecological approach to restore the MBO, to reduce the risk of opportunistic infections and other OL during chemotherapy treatment.
PubMed: 38390612
DOI: 10.21142/2523-2754-1004-2022-131 -
ISME Communications Jan 2024Pneumococcal carriage studies have suggested that pneumococcal colonization in adults is largely limited to the oral cavity and oropharynx. In this study, we used total...
Pneumococcal carriage studies have suggested that pneumococcal colonization in adults is largely limited to the oral cavity and oropharynx. In this study, we used total abundance-based β-diversity (dissimilarity) and β-diversity components to characterize age-related differences in pneumococcal serotype composition of respiratory samples. quantitative PCR (qPCR) was applied to detect pneumococcal serotypes in nasopharyngeal samples collected from 946 toddlers and 602 adults, saliva samples collected from a subset of 653 toddlers, and saliva and oropharyngeal samples collected from a subset of 318 adults. Bacterial culture rates from nasopharyngeal samples were used to characterize age-related differences in rates of colonizing bacteria. Dissimilarity in pneumococcal serotype composition was low among saliva and nasopharyngeal samples from children. In contrast, respiratory samples from adults exhibited high serotype dissimilarity, which predominantly consisted of abundance gradients and was associated with reduced nasopharyngeal colonization. Age-related serotype dissimilarity was high among nasopharyngeal samples and relatively low for saliva samples. Reduced nasopharyngeal colonization by pneumococcal serotypes coincided with significantly reduced and and increased nasopharyngeal colonization rates among adults. Findings from this study suggest that within-host environmental conditions, utilized in the upper airways by pneumococcus and other bacteria, undergo age-related changes. It may result in a host-driven ecological succession of bacterial species colonizing the nasopharynx and lead to competitive exclusion of pneumococcus from the nasopharynx but not from the oral habitat. This explains the poor performance of nasopharyngeal samples for pneumococcal carriage among adults and indicates that in adults saliva more accurately represents the epidemiology of pneumococcal carriage than nasopharyngeal samples.
PubMed: 38390521
DOI: 10.1093/ismeco/ycae002 -
Frontiers in Cellular and Infection... 2024
Topics: Humans; Coinfection; Streptococcus pneumoniae; Anti-Bacterial Agents
PubMed: 38357443
DOI: 10.3389/fcimb.2024.1370067 -
Anales de Pediatria Mar 2024Recent studies show an increase in the prevalence of Haemophilus influenzae and a decrease in Streptococcus pneumoniae among the bacteria that cause acute otitis media...
INTRODUCTION
Recent studies show an increase in the prevalence of Haemophilus influenzae and a decrease in Streptococcus pneumoniae among the bacteria that cause acute otitis media (AOM). The objective of our study was to analyse the distribution of pathogens identified in children aged less than 14 years presenting to the emergency department with AOM and their patterns of antimicrobial resistance.
PATIENTS AND METHODS
Single centre retrospective, analytical study in patients aged less than 14 years with a diagnosis of AOM in whom an ear drainage sample was collected for culture in the paediatric emergency department of a tertiary care hospital between 2013 and 2021.
RESULTS
During the study period, there were 14 684 documented care episodes corresponding to children with a diagnosis of AOM. An ear drainage culture was performed in 768 of those episodes. The median age of the patients was 2 years, 57% were male and 70% had a previous history of AOM. The most frequently isolated pathogens were: Haemophilus influenzae (n = 188 [24.5%]; 15.5% of them resistant to ampicillin), Streptococcus pyogenes (n = 86 [11.2%]), Staphylococcus aureus (n = 82 [10.7%]), Streptococcus pneumoniae (n = 54 [6.9%]; 9.4% with intermediate resistance to penicillin), Pseudomonas aeruginosa (n = 42 [5.5%]) and Moraxella catarrhalis (n = 11 [1.4%]). No pathogen was isolated in 34.9% of cases.
CONCLUSIONS
Haemophilus influenzae is the leading cause of AOM in children aged less than 14 years. This, combined with the low frequency of isolation and penicillin resistance of Streptococcus pneumoniae, calls into question the appropriateness of high-dose amoxicillin for empiric treatment of AOM.
Topics: Child; Humans; Male; Child, Preschool; Female; Anti-Bacterial Agents; Retrospective Studies; Drug Resistance, Bacterial; Microbial Sensitivity Tests; Otitis Media; Streptococcus pneumoniae; Streptococcus pyogenes; Haemophilus influenzae
PubMed: 38350792
DOI: 10.1016/j.anpede.2023.12.013 -
ERJ Open Research Jan 2024The lung microbiome is an inflammatory stimulus whose role in COPD pathogenesis is incompletely understood. We hypothesised that the frequent exacerbator phenotype is...
BACKGROUND
The lung microbiome is an inflammatory stimulus whose role in COPD pathogenesis is incompletely understood. We hypothesised that the frequent exacerbator phenotype is associated with decreased α-diversity and increased lung inflammation. Our objective was to assess correlations between the frequent exacerbator phenotype, the microbiome and inflammation longitudinally during exacerbation-free periods.
METHODS
We conducted a case-control longitudinal observational study of the frequent exacerbator phenotype and characteristics of the airway microbiome. 81 subjects (41 frequent and 40 infrequent exacerbators) provided nasal, oral and sputum microbiome samples at two visits over 2-4 months. Exacerbation phenotype, relevant clinical factors and sputum cytokine values were associated with microbiome findings.
RESULTS
The frequent exacerbator phenotype was associated with lower sputum microbiome α-diversity (p=0.0031). This decrease in α-diversity among frequent exacerbators was enhanced when the sputum bacterial culture was positive (p<0.001). Older age was associated with decreased sputum microbiome α-diversity (p=0.0030). Between-visit β-diversity was increased among frequent exacerbators and those who experienced a COPD exacerbation between visits (p=0.025 and p=0.014, respectively). Sputum cytokine values did not differ based on exacerbation phenotype or other clinical characteristics. Interleukin (IL)-17A was negatively associated with α-diversity, while IL-6 and IL-8 were positively associated with α-diversity (p=0.012, p=0.012 and p=0.0496, respectively). IL-22, IL-17A and IL-5 levels were positively associated with abundance (p=0.027, p=0.0014 and p=0.0020, respectively).
CONCLUSIONS
Even during exacerbation-free intervals, the COPD frequent exacerbator phenotype is associated with decreased sputum microbiome α-diversity and increased β-diversity. Decreased sputum microbiome α-diversity and abundance are associated with lung inflammation.
PubMed: 38333651
DOI: 10.1183/23120541.00595-2023