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BMC Infectious Diseases Sep 2021Descending necrotizing mediastinitis (DNM) is one of the most virulent forms of mediastinitis. The main causes of high mortality in DNM are believed to stem from...
BACKGROUND
Descending necrotizing mediastinitis (DNM) is one of the most virulent forms of mediastinitis. The main causes of high mortality in DNM are believed to stem from difficulty and delay in the diagnosis. Fast and accurate identification of pathogens is important for the treatment of these patients. Metagenomics next-generation sequencing (mNGS) is a powerful tool to identify all kinds of pathogens, especially for rare and complex infections.
CASE PRESENTATION
A 64-year-old male patient was admitted to the intensive care unit (ICU) with unconsciousness, dyspnea, and swelling in the mandible and neck. Computed tomography (CT) scan results combined with clinical laboratory examination indicated DNM. Vancomycin and imipenem were used, and vacuum sealing drainage was applied for debridement and drainage of the infected area. The positive mNGS results of drainage fluid confirmed the presence of mixed infection caused by Streptococcus anginosus, Prevotella oris, and several other anaerobes. The antibiotics were adjusted to piperacillin/tazobactam and tinidazole according to the mNGS results and antimicrobial susceptibility testing of cultured pathogens. After 11 days of antibiotic therapy, the infection symptoms of the neck and mediastinum improved, and the patient was transferred out of the ICU on the 26 day after negative result of drainage fluid culture.
CONCLUSION
This case suggested that mNGS is a promising technology for precise and fast pathogens identification with high sensitivity, which may guide the diagnosis of infectious diseases in the future trend.
Topics: Coinfection; High-Throughput Nucleotide Sequencing; Humans; Male; Mediastinitis; Metagenomics; Middle Aged; Necrosis; Prevotella
PubMed: 34479479
DOI: 10.1186/s12879-021-06624-4 -
ERJ Open Research Apr 2021Childhood lower respiratory tract infections (LRTI) are associated with dysbiosis of the nasopharyngeal microbiota, and persistent dysbiosis following the LRTI may in...
Childhood lower respiratory tract infections (LRTI) are associated with dysbiosis of the nasopharyngeal microbiota, and persistent dysbiosis following the LRTI may in turn be related to recurrent or chronic respiratory problems. Therefore, we aimed to investigate microbial and clinical predictors of early recurrence of respiratory symptoms as well as recovery of the microbial community following hospital admission for LRTI in children. To this end, we collected clinical data and characterised the nasopharyngeal microbiota of 154 children (4 weeks-5 years old) hospitalised for a LRTI (bronchiolitis, pneumonia, wheezing illness or mixed infection) at admission and 4-8 weeks later. Data were compared to 307 age-, sex- and time-matched healthy controls. During follow-up, 66% of cases experienced recurrence of (mild) respiratory symptoms. In cases with recurrence of symptoms during follow-up, we found distinct nasopharyngeal microbiota at hospital admission, with higher levels of and other gram-negatives and lower levels of and compared with healthy controls. Furthermore, in cases with recurrence of respiratory symptoms, recovery of the microbiota was also diminished. Especially in cases with wheezing illness, we observed a high rate of recurrence of respiratory symptoms, as well as diminished microbiota recovery at follow-up. Together, our results suggest a link between the nasopharyngeal microbiota composition during LRTI and early recurrence of respiratory symptoms, as well as diminished microbiota recovery after 4-8 weeks. Future studies should investigate whether (speed of) ecological recovery following childhood LRTI is associated with long-term respiratory problems.
PubMed: 34195257
DOI: 10.1183/23120541.00939-2020 -
Frontiers in Microbiology 2021Previous studies have focused on the rumen microbiome and enteric methane (CH) emissions in dairy cows, yet little is known about steers, especially steers of dairy...
Previous studies have focused on the rumen microbiome and enteric methane (CH) emissions in dairy cows, yet little is known about steers, especially steers of dairy breeds. In the present study, we comparatively examined the rumen microbiota, fermentation characteristics, and CH emissions from six non-cannulated Holstein (710.33 ± 43.02 kg) and six Jersey (559.67 ± 32.72 kg) steers. The steers were fed the same total mixed ration (TMR) for 30 days. After 25 days of adaptation to the diet, CH emissions were measured using GreenFeed for three consecutive days, and rumen fluid samples were collected on last day using stomach tubing before feeding (0 h) and 6 h after feeding. CH production (g/d/animal), CH yield (g/kg DMI), and CH intensity (g/kg BW) were higher in the Jersey steers than in the Holstein steers. The lowest pH value was recorded at 6 h after feeding. The Jersey steers had lower rumen pH and a higher concentration of ammonia-nitrogen (NH-N). The Jersey steers had a numerically higher molar proportion of acetate than the Holstein steers, but the opposite was true for that of propionate. Metataxonomic analysis of the rumen microbiota showed that the two breeds had similar species richness, Shannon, and inverse Simpson diversity indexes. Principal coordinates analysis showed that the overall rumen microbiota was different between the two breeds. Both breeds were dominated by , and its highest relative abundance was observed 6 h after feeding. The genera , , and the species , and were more abundant in Holstein steers while the genera , , and the species , and in the Jersey steers. The Jersey steers were dominated by while the Holstein steers by . The overall results suggest that sampling hour has little influence on the rumen microbiota; however, breeds of steers can affect the assemblage of the rumen microbiota and different mitigation strategies may be needed to effectively manipulate the rumen microbiota and mitigate enteric CH emissions from these steers.
PubMed: 33868186
DOI: 10.3389/fmicb.2021.601061 -
Cureus May 2020Empyema necessitasis (EN) also referred to as empyema necessitans (EN) is a rare complication of empyema that can involve soft tissues outside the pleural cavity and can...
Empyema necessitasis (EN) also referred to as empyema necessitans (EN) is a rare complication of empyema that can involve soft tissues outside the pleural cavity and can lead to brachial plexus injury. Although, brachial plexus injury most commonly occurs as a result of trauma, inflammation, or malignancies, but it has been rarely seen in EN. We are reporting a rare and challenging case of empyema necessitasis (EN) causing impingement of brachial plexus in a 42-year-old, type 2 diabetic patient, who initially presented to the hospital with left-sided pleuritic chest pain and acute onset of left upper limb weakness. Urgent CT brain ruled out an acute neurological insult. Chest radiograph and contrast-enhanced CT thorax revealed left-sided loculated effusion. MRI of the left upper limb showed impingement of brachial plexus by the inflammatory process of surrounding effusion. Ultrasound-guided aspiration of the encapsulated fluid was performed and culture analysis of the fluid was remarkable for Prevotella oris (sensitive strain) growth. After drainage of the infected fluid and with a prolonged course of antibiotics, the patient's neurological symptoms improved significantly. Hospital course was uncomplicated and further follow-up was unremarkable for any deterioration. Our objective is to emphasize on the prompt management with close follow-up in EN, which can present with life-threatening complications as seen in our case. Any delay can compromise the patient's health. As per our limited knowledge, this case has not been reported in the literature.
PubMed: 32596084
DOI: 10.7759/cureus.8267 -
Journal of Thoracic Disease Oct 2019Culture-independent methods such as quantitative polymerase chain reaction (qPCR) are more sensitive for detecting pathogens than conventional culture. This study aimed...
Potential clinical utility of multiple target quantitative polymerase chain reaction (qPCR) array to detect microbial pathogens in patients with chronic obstructive pulmonary disease (COPD).
BACKGROUND
Culture-independent methods such as quantitative polymerase chain reaction (qPCR) are more sensitive for detecting pathogens than conventional culture. This study aimed to test the clinical potential of a multiple target qPCR array in identifying sputum pathogens, compared to traditional culture.
METHODS
Forty chronic obstructive pulmonary disease (COPD) patients provided spontaneous sputum and blood samples during an exacerbation event (n=25 patients) and in stable state (n=15 patients). Sputum was processed and analysed by microscopy, culture and sensitivity testing (MCS) to identify living microbial isolates, and multiple target qPCR (44 targets for bacterial and fungal pathogens and antibiotic resistance genes), and 16S rRNA gene sequencing.
RESULTS
Six microbial isolates (5 bacterial, 1 fungal) were cultured from 20 exacerbation and 10 stable patient sputum samples. Four of these microbial isolates had their presence in patient sputum confirmed by qPCR. All bacterial targets detected by qPCR were further confirmed by 16S rRNA gene sequencing at a genus level. qPCR identified significantly more bacterial pathogens than culture (P<0.001). The most prevalent bacterial species identified by qPCR were (72% of patients), (40%), (32%) and (17%). Microbial species diversity and richness were not significantly different between samples obtained from exacerbating and clinically stable cases. 16S rRNA gene sequencing identified (P=0.022, FDR =0.043 AUC =0.72) as a significantly different bacterial OTU (operational taxonomic units) in exacerbation sputum samples compared to stable state samples.
CONCLUSIONS
Multiple target qPCR was more sensitive for detection of sputum pathogens in COPD patients than conventional culture. 16S rRNA gene sequencing confirmed the identity at a genus level of all bacterial targets detected by qPCR, as well as identifying bacterial OTUs that could potentially be used to distinguish between exacerbation and stable COPD disease states. Multiple target qPCR pathogen detection in the sputum of COPD patients warrants further investigation to determine how it may influence COPD clinical management.
PubMed: 31737352
DOI: 10.21037/jtd.2019.10.39 -
Microbiome Apr 2019Gastrointestinal mucosal injury (mucositis), commonly affecting the oral cavity, is a clinically significant yet incompletely understood complication of cancer... (Observational Study)
Observational Study
BACKGROUND
Gastrointestinal mucosal injury (mucositis), commonly affecting the oral cavity, is a clinically significant yet incompletely understood complication of cancer chemotherapy. Although antineoplastic cytotoxicity constitutes the primary injury trigger, the interaction of oral microbial commensals with mucosal tissues could modify the response. It is not clear, however, whether chemotherapy and its associated treatments affect oral microbial communities disrupting the homeostatic balance between resident microorganisms and the adjacent mucosa and if such alterations are associated with mucositis. To gain knowledge on the pathophysiology of oral mucositis, 49 subjects receiving 5-fluorouracil (5-FU) or doxorubicin-based chemotherapy were evaluated longitudinally during one cycle, assessing clinical outcomes, bacterial and fungal oral microbiome changes, and epithelial transcriptome responses. As a control for microbiome stability, 30 non-cancer subjects were longitudinally assessed. Through complementary in vitro assays, we also evaluated the antibacterial potential of 5-FU on oral microorganisms and the interaction of commensals with oral epithelial tissues.
RESULTS
Oral mucositis severity was associated with 5-FU, increased salivary flow, and higher oral granulocyte counts. The oral bacteriome was disrupted during chemotherapy and while antibiotic and acid inhibitor intake contributed to these changes, bacteriome disruptions were also correlated with antineoplastics and independently and strongly associated with oral mucositis severity. Mucositis-associated bacteriome shifts included depletion of common health-associated commensals from the genera Streptococcus, Actinomyces, Gemella, Granulicatella, and Veillonella and enrichment of Gram-negative bacteria such as Fusobacterium nucleatum and Prevotella oris. Shifts could not be explained by a direct antibacterial effect of 5-FU, but rather resembled the inflammation-associated dysbiotic shifts seen in other oral conditions. Epithelial transcriptional responses during chemotherapy included upregulation of genes involved in innate immunity and apoptosis. Using a multilayer epithelial construct, we show mucositis-associated dysbiotic shifts may contribute to aggravate mucosal damage since the mucositis-depleted Streptococcus salivarius was tolerated as a commensal, while the mucositis-enriched F. nucleatum displayed pro-inflammatory and pro-apoptotic capacity.
CONCLUSIONS
Altogether, our work reveals that chemotherapy-induced oral mucositis is associated with bacterial dysbiosis and demonstrates the potential for dysbiotic shifts to aggravate antineoplastic-induced epithelial injury. These findings suggest that control of oral bacterial dysbiosis could represent a novel preventive approach to ameliorate oral mucositis.
Topics: Antineoplastic Agents; Bacteria; Drug Therapy; Drug-Related Side Effects and Adverse Reactions; Dysbiosis; Fluorouracil; Fungi; Humans; Inflammation; Longitudinal Studies; Microbiota; Mouth; Mouth Mucosa; Prospective Studies; Stomatitis
PubMed: 31018870
DOI: 10.1186/s40168-019-0679-5 -
Journal of Endodontics Aug 2016The purpose of this study was to combine multiple displacement amplification and checkerboard DNA-DNA hybridization to qualitatively and quantitatively evaluate the...
INTRODUCTION
The purpose of this study was to combine multiple displacement amplification and checkerboard DNA-DNA hybridization to qualitatively and quantitatively evaluate the microbiota present in infections refractory to endodontic treatment.
METHODS
The subjects of this study were 40 patients presenting with periapical lesions refractory to endodontic treatment. Samples were taken by scraping or filing root canal walls with a #10 K-type hand file. Sample DNA was amplified by multiple displacement amplification, and the levels of 107 bacterial taxa were analyzed by checkerboard DNA-DNA hybridization. The taxa were divided into 3 distinct microbial populations depending on their mean proportion in samples (% DNA probe counts ± standard error of the mean) as follows: dominant (≥3.0%), subdominant (>1.6%-3.0%), and residual (≤1.6%) populations. The significance of differences was determined using the Mann-Whitney test.
RESULTS
The taxa present with the highest mean proportions (constituting the dominant population) were Corynebacterium diphtheriae (8.03 ± 0.98), Porphyromonas gingivalis (5.42 ± 2.09), Streptococcus sobrinus (5.33 ± 0.69), and Stenotrophomonas maltophilia (4.72 ± 1.73). Among the subdominant population were Eubacterium saphenum (3.85 ± 1.06), Helicobacter pylori (3.16 ± 0.62), Dialister pneumosintes (3.12 ± 1.1), Clostridium difficile (2.74 ± 0.41), Enterobacter agglomerans (2.64 ± 0.54), Salmonella enterica (2.51 ± 0.52), Mobiluncus mulieris (2.44 ± 0.6), and Klebsiella oxytoca (2.32 ± 0.66). In the population of bacteria present at the lowest mean proportions (the residual population), Bacteroides ureolyticus (0.04 ± 0.01), Haemophilus influenzae (0.04 ± 0.02), and Prevotella oris (0.01 ± 0.01) were found at the lowest mean proportions. Enterococcus faecalis was detected in the residual population (0.52 ± 0.26).
CONCLUSIONS
The microbial climax community in teeth refractory to endodontic treatment not only harbors medically important species but also contains distinct microbial consortia present with different population levels.
Topics: Bacteria; DNA Probes; DNA, Bacterial; Dental Pulp Cavity; Dental Pulp Necrosis; Humans; Microbiota; Nucleic Acid Hybridization; Periapical Diseases; Root Canal Therapy
PubMed: 27377440
DOI: 10.1016/j.joen.2016.05.014 -
Journal of Oral Microbiology 2015Usefulness of next-generation sequencing (NGS) in assessing bacteria associated with oral squamous cell carcinoma (OSCC) has been undermined by inability to classify...
BACKGROUND
Usefulness of next-generation sequencing (NGS) in assessing bacteria associated with oral squamous cell carcinoma (OSCC) has been undermined by inability to classify reads to the species level.
OBJECTIVE
The purpose of this study was to develop a robust algorithm for species-level classification of NGS reads from oral samples and to pilot test it for profiling bacteria within OSCC tissues.
METHODS
Bacterial 16S V1-V3 libraries were prepared from three OSCC DNA samples and sequenced using 454's FLX chemistry. High-quality, well-aligned, and non-chimeric reads ≥350 bp were classified using a novel, multi-stage algorithm that involves matching reads to reference sequences in revised versions of the Human Oral Microbiome Database (HOMD), HOMD extended (HOMDEXT), and Greengene Gold (GGG) at alignment coverage and percentage identity ≥98%, followed by assignment to species level based on top hit reference sequences. Priority was given to hits in HOMD, then HOMDEXT and finally GGG. Unmatched reads were subject to operational taxonomic unit analysis.
RESULTS
Nearly, 92.8% of the reads were matched to updated-HOMD 13.2, 1.83% to trusted-HOMDEXT, and 1.36% to modified-GGG. Of all matched reads, 99.6% were classified to species level. A total of 228 species-level taxa were identified, representing 11 phyla; the most abundant were Proteobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Actinobacteria. Thirty-five species-level taxa were detected in all samples. On average, Prevotella oris, Neisseria flava, Neisseria flavescens/subflava, Fusobacterium nucleatum ss polymorphum, Aggregatibacter segnis, Streptococcus mitis, and Fusobacterium periodontium were the most abundant. Bacteroides fragilis, a species rarely isolated from the oral cavity, was detected in two samples.
CONCLUSION
This multi-stage algorithm maximizes the fraction of reads classified to the species level while ensuring reliable classification by giving priority to the human, oral reference set. Applying the algorithm to OSCC samples revealed high diversity. In addition to oral taxa, a number of human, non-oral taxa were also identified, some of which are rarely detected in the oral cavity.
PubMed: 26426306
DOI: 10.3402/jom.v7.28934 -
Clinical Oral Investigations May 2015Early colonisation of oral surfaces by periodontal pathogens presents a significant risk factor for subsequent development of destructive disease affecting tissues that...
OBJECTIVES
Early colonisation of oral surfaces by periodontal pathogens presents a significant risk factor for subsequent development of destructive disease affecting tissues that support the dentition. The aims of the present study were to establish the age-dependent relationship between sub-gingival profiles of 22 Prevotella species/phylotypes in children, adolescents and adults from an isolated Aboriginal community and, further, to use this information to identify Prevotella species that could serve as microbial risk indicators.
MATERIALS AND METHODS
DNA isolated from sub-gingival plaque samples (three healthy sites and three inflamed/diseased sites) from adults, adolescents and children was screened for Porphyromonas gingivalis load and 22 Prevotella species/phylotypes by species-specific PCR.
RESULTS
A noticeable feature in adolescents was the marked increase in colonisation by P. gingivalis across all test sites. The mean number of Prevotella species/phylotypes colonising inflamed/diseased sub-gingival sites increased with age. Progressive partitioning of selected Prevotella species/phylotypes to healthy or inflamed/diseased sites was evident. Prevalence of Prevotella intermedia, Prevotella oral clone P4PB_24 and Prevotella oris increased significantly with age in diseased sites. Similarly, significant age-dependent increase in colonisation of healthy as well as inflamed/diseased sub-gingival sites was apparent for Prevotella oralis, Prevotella multiformis, Prevotella denticola, Prevotella strain P4P_53 and Prevotella oral clone BR014.
CONCLUSION
Early colonisation of children by P. gingivalis, P. intermedia and Prevotella oral clone P4PB_24 provides indication of risk for subsequent development of periodontal disease.
CLINICAL RELEVANCE
In the present study, the complexity of Prevotella species within gingival sites is explored as a basis for evaluating contribution of Prevotella species to disease.
Topics: Adolescent; Adult; Age Factors; Aged; Child; Child, Preschool; Cohort Studies; DNA, Bacterial; Female; Gingiva; Humans; Male; Middle Aged; Native Hawaiian or Other Pacific Islander; New South Wales; Periodontal Diseases; Polymerase Chain Reaction; Porphyromonas gingivalis; Prevotella; Young Adult
PubMed: 25106846
DOI: 10.1007/s00784-014-1301-7 -
Journal of Microbiology, Immunology,... Jun 2014The coaggregation of bacteria has been defined as one of the most important processes in the oral infection such as periodontitis. Prevotella oris and Porphyromonas...
BACKGROUND/PURPOSE
The coaggregation of bacteria has been defined as one of the most important processes in the oral infection such as periodontitis. Prevotella oris and Porphyromonas gingivalis, which are two of the periodontopathogens, are frequently detected in severe forms of periodontal diseases. However, the interaction between P. oris and P. gingivalis is still unknown. In this study, the coaggregation of P. oris with nine oral bacterial species including P. gingivalis was examined.
METHODS
All bacteria used in this study were cultured anaerobically and suspended in coaggregation buffer. Each cell suspension was mixed in a test tube and subjected to shaking at room temperature for 1 hour. Subsequently, the coaggregation values were scored. Furthermore, the effects of various chemical reagents, and heat, proteinase K, and serum treatment were examined.
RESULTS
In this study, P. oris coaggregated only with P. gingivalis. A heat-stable, nonproteinous component of P. oris and a heat-labile, proteinous component of P. gingivalis play important roles in this coaggregation. In addition, this coaggregation was inhibited by l-arginine, l-lysine, and Nα-p-tosyl-l-lysine. Therefore, it was considered that a cell surface protein on P. gingivalis, such as gingipain, may be involved in the coaggregation. Furthermore, the coaggregation was not inhibited by serum treatment.
CONCLUSION
This is the first report to describe the coaggregation of P. oris and P. gingivalis. Our study proposes the possibility that P. oris may promote the colonization of P. gingivalis in an early stage of biofilm formation. Furthermore, this coaggregation may contribute to the initiation and progression of periodontitis.
Topics: Animals; Biofilms; Coculture Techniques; Endopeptidase K; Horses; Hot Temperature; Humans; Microbial Interactions; Periodontitis; Porphyromonas gingivalis; Prevotella; Serum
PubMed: 23245806
DOI: 10.1016/j.jmii.2012.09.005