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Frontiers in Pediatrics 2020Molecular assays for infectious diseases have emerged as important clinical decision-making tools. Unbiased, metagenomic next-generation sequencing is a novel approach...
Molecular assays for infectious diseases have emerged as important clinical decision-making tools. Unbiased, metagenomic next-generation sequencing is a novel approach holding promise to detect pathogens missed by conventional modalities and to deconvolute admixed nucleic acid sequences from polymicrobial infections in order to identify constituent pathogens. Recent studies have raised concerns about the clinical impact of metagenomics assays and whether their expense is justified. Here, we report a case of polyclonal endocarditis in a 14-year-old woman with a history of Tetralogy of Fallot. Three sets of admission blood cultures and a commercial plasma metagenomics assay were negative for pathogens, despite persistent vegetations observed on the valve during a later procedure. Multiple strains of were identified from the explanted valve by amplicon-based 16S rRNA sequencing, confirming the patient had received appropriate antibiotic therapy. This case highlights limitations in the use and interpretation of clinical metagenomics for infectious disease diagnosis and indicates that the clinical yield of these tools may depend upon infection type and anatomic location.
PubMed: 33489996
DOI: 10.3389/fped.2020.575674 -
ACS Synthetic Biology Sep 20202,5-Dimethylpyrazine (2,5-DMP) is an indispensable additive for flavoring in the food industry and an important substrate for producing hypoglycemic and antilipolytic...
2,5-Dimethylpyrazine (2,5-DMP) is an indispensable additive for flavoring in the food industry and an important substrate for producing hypoglycemic and antilipolytic drugs. However, 2,5-DMP is produced by chemical synthesis in industry. Herein, a "green" strategy to produce 2,5-DMP has been reported for the first time. To do this, we rewrote the 2,5-DMP biosynthesis pathway and substrate transmembrane transport in an l-threonine high-yielding strain to promote highly efficient 2,5-DMP production from glucose by submerged fermentation. The final strain T6-47-7 could produce 1.43 ± 0.07 g/L of 2,5-DMP with a carbon yield of 6.78% and productivity of 0.715 g/(L·d) in shake-flask fermentation using a phase-wise manner of hypoxia-inducible expression. The design-based strategy for constructing the 2,5-DMP high-yielding strain reported here could serve as a general concept for breeding high-yielding strains that produce some other type of alkylpyrazine.
Topics: Alcohol Oxidoreductases; Biosynthetic Pathways; Escherichia coli; Glucose; Metabolic Engineering; NAD; Oxidoreductases Acting on CH-NH Group Donors; Phylogeny; Pyrazines; Streptococcus; Polyamine Oxidase
PubMed: 32841563
DOI: 10.1021/acssynbio.0c00329 -
Applied and Environmental Microbiology Jun 2020The human oral cavity is a complex ecosystem, and the alterations in salivary microbial communities are associated with both oral and nonoral diseases. The Mediterranean...
The human oral cavity is a complex ecosystem, and the alterations in salivary microbial communities are associated with both oral and nonoral diseases. The Mediterranean diet (MD) is a healthy dietary pattern useful for both prevention and treatment of several diseases. To further explore the effects of the MD on human health, in this study, we investigated the changes in the salivary microbial communities in overweight/obese subjects after an individually tailored MD-based nutritional intervention. Healthy overweight and obese subjects were randomized between two intervention groups. The MD group (Med-D group) increased their MD adherence during 8 weeks of intervention while the control diet (control-D) group did not change their dietary habits. The salivary microbiota was assessed at baseline and after 4 and 8 weeks of intervention. Despite no observed changes in the overall salivary microbiota composition, we found a significant decrease in the relative abundances of species-level operational taxonomic units annotated as , , and in the Med-D group compared to that in the control-D group after 8 weeks of intervention, which are known to be associated with periodontal disease. Such variations were significantly linked to dietary variables such as MD adherence rates and intakes of animal versus vegetable proteins. In addition, increased levels of were observed in the Med-D group, which has been reported as an antagonistic taxon inhibiting gene expression. Our findings suggest that an MD-based nutritional intervention may be implicated in reducing periodontal bacteria, and an MD may be a dietary strategy supportive of oral homeostasis. Changes in dietary behavior with increased adherence to a Mediterranean diet can determine a reduction of periodontopathogenic bacterial abundances in the saliva of overweight subjects with cardiometabolic risk due to an unhealthy lifestyle, without any change in individual energy intake, nutrient intake, and physical activity.
Topics: Adult; Bacterial Physiological Phenomena; Diet, Mediterranean; Female; Humans; Male; Middle Aged; Obesity; Overweight; Periodontal Diseases; Random Allocation; Saliva; Young Adult
PubMed: 32276980
DOI: 10.1128/AEM.00777-20 -
Journal of Clinical Orthopaedics and... 2020Septic Arthritis of the wrist is rare in the paediatric population due to its extraarticular metaphysis. We report here a case of wrist septic arthritis in a neonate...
Septic Arthritis of the wrist is rare in the paediatric population due to its extraarticular metaphysis. We report here a case of wrist septic arthritis in a neonate caused by an uncommon causative organism, A 15 days old male child was referred with the complaint of swelling and decreased movement of the left wrist for 5 days. Local examination revealed warm, tender, erythematous and fluctuant swelling over the dorso-ulnar aspect of the left wrist. Ultrasonography of the affected region was suggestive of focal fluid collection in the wrist and periosteal elevation of the distal ulna. Aspiration followed by arthrotomy of the wrist joint was performed and multiple holes were made in the distal ulnar metaphysis using 0.8mm k-wire. The pus culture was positive for sensitive to vancomycin, which was given for a total of 4 weeks. At one year follow up the child had a full, painless range of motion with no functional deficit. Final follow up x rays of the left wrist were normal. strains are described as Gram-positive, catalase-negative cocci, approximately 1 μm in diameter growing in chains and were originally isolated from the human throat and oral cavities. Its association with bone and joint infections has not been described in the literature. To our knowledge, this is the first case of isolated septic arthritis of wrist in a 15 days old child caused by To conclude, wrist septic arthritis in a neonate is a rare entity. With the advanced diagnostics, species-level identification of rare organism like is possible along with antibiotic sensitivity for appropriate therapy. Early surgical decompression and intravenous culture-directed antibiotics are the mainstays of management.
PubMed: 32099306
DOI: 10.1016/j.jcot.2019.02.002 -
BMC Nephrology Jan 2020Diagnosis and treatment of either ANCA disease or silent infection-related glomerulonephritis is complicated and is a huge treatment challenge when overlapping clinical... (Review)
Review
Diagnostic and treatment challenge of unrecognized subacute bacterial endocarditis associated with ANCA-PR3 positive immunocomplex glomerulonephritis: a case report and literature review.
BACKGROUND
Diagnosis and treatment of either ANCA disease or silent infection-related glomerulonephritis is complicated and is a huge treatment challenge when overlapping clinical manifestations occur. We report a case of ANCA-PR3 glomerulonephritis, nervous system involvement, hepatosplenomegaly and clinically silent subacute infectious endocarditis.
CASE PRESENTATION
A 57-year-old man with known mitral valve prolaps was admitted for unexplained renal failure with signs of nephritic syndrome, hepatosplenomegaly, sudden unilateral hearing loss, vertigo, malaise, new onset hemolytic anemia and thrombocytopenia. Immunoserology revealed positive c-anti-neutrophil cytoplasm antibody (ANCA)/anti-proteinase 3 (anti-PR3), mixed type crioglobulinemia and lowered complement fraction C3. Head MRI showed many microscopic hemorrhages. Common site of infection, as well as solid malignoma were ruled out. In accordance with clinical and laboratory findings, systemic vasculitis was assumed, although the etiology remained uncertain (ANCA-associated, cryoglobulinemic or related to unrecognized infection). After kidney biopsy, clinical signs of sepsis appeared. Blood cultures revealed Streptococcus cristatus. Echocardiography showed mitral valve endocarditis. Kidney biopsy revealed proliferative, necrotizing immunocomplex glomerulonephritis. Half a year later, following intravenous immunoglobulins, glucocorticoids, antibiotic therapy and surgical valve repair, the creatinine level decreased and c-ANCA and cryoglobulins disappeared. A second kidney biopsy revealed no residual kidney disease. Four years after treatment, the patient is stable with no symptoms or signs of vasculitis recurrence.
CONCLUSIONS
Here we describe the diagnostic and treatment challenge in a patient with unrecognized subacute bacterial endocarditis associated with ANCA-PR3 immunocomplex proliferative and crescentic glomerulonephritis. In patients with ANCA-PR3 immunocomplex glomerulonephritis and other overlapping manifestations suggesting systemic disease, it is important to recognize and aggressively treat any possible coexisting bacterial endocarditis, This is the most important step for a favorable patient outcome, including complete clinical and pathohistological resolution of the glomerulonephritis.
Topics: Anti-Bacterial Agents; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Asymptomatic Diseases; Cryoglobulinemia; Endocarditis, Bacterial; Glomerulonephritis; Glucocorticoids; Humans; Immunoglobulins, Intravenous; Immunologic Factors; Male; Middle Aged; Mitral Valve Prolapse; Myeloblastin
PubMed: 32005179
DOI: 10.1186/s12882-020-1694-2 -
Microorganisms Sep 2019Adolescence is closely associated with a high risk of caries. The identification of specific bacteria in an oral microniche, the interdental space of the molars,...
Adolescence is closely associated with a high risk of caries. The identification of specific bacteria in an oral microniche, the interdental space of the molars, according to carious risk can facilitate the prediction of future caries and the anticipation of the progression or stabilization of caries in adolescents. A cross-sectional clinical study according to the bacteriological criteria of interdental healthy adolescents and carious risk factors-low and high-using a real-time polymerase chain reaction technique was conducted. The presence of 26 oral pathogens from the interdental microbiota of 50 adolescents aged 15 to 17 years were qualitatively and quantitatively analyzed. Bacteria known to be cariogenic (, spp., , , , , , and ) did not present differences in abundance according to carious risk. Periodontal bacteria from the red complex are positively correlated with carious risk. However, only 3 bacteria-, and -presented a significant increase in the highest group. Estimating the risk of caries associated with bacterial factors in interdental sites of molars in adolescents contributes to the better definition of carious risk status, periodicity and intensity of diagnostic, prevention and restorative services.
PubMed: 31491909
DOI: 10.3390/microorganisms7090319 -
Applied and Environmental Microbiology May 2019-Acetylglucosamine (GlcNAc) and glucosamine (GlcN) enhance the competitiveness of the laboratory strain DL1 of against the caries pathogen Here, we examine how amino...
-Acetylglucosamine (GlcNAc) and glucosamine (GlcN) enhance the competitiveness of the laboratory strain DL1 of against the caries pathogen Here, we examine how amino sugars affect the interaction of five low-passage-number clinical isolates of abundant commensal streptococci with by utilizing a dual-species biofilm model. Compared to that for glucose, growth on GlcN or GlcNAc significantly reduced the viability of in cocultures with most commensals, shifting the proportions of species. Consistent with these results, production of HO was increased in most commensals when growing on amino sugars, and inhibition of by , , or was enhanced by amino sugars on agar plates. All commensals except had higher arginine deiminase activities when grown on GlcN and, in some cases, GlcNAc. In biofilms formed using pooled cell-containing saliva (CCS), the proportions of were drastically diminished when GlcNAc was the primary carbohydrate. Increased production of HO could account in large part for the inhibitory effects of CCS biofilms. Surprisingly, amino sugars appeared to improve mutacin production by on agar plates, suggesting that the commensals have mechanisms to actively subvert antagonism by in cocultures. Collectively, these findings demonstrate that amino sugars can enhance the beneficial properties of low-passage-number commensal oral streptococci and highlight their potential for moderating the cariogenicity of oral biofilms. Dental caries is driven by dysbiosis of oral biofilms in which dominance by acid-producing and acid-tolerant bacteria results in loss of tooth mineral. Our previous work demonstrated the beneficial effects of amino sugars GlcNAc and GlcN in promoting the antagonistic properties of a health-associated oral bacterium, , in competition with the major caries pathogen Here, we investigated 5 low-passage-number clinical isolates of the most common streptococcal species to establish how amino sugars may influence the ecology and virulence of oral biofilms. Using multiple models, including a human saliva-derived microcosm biofilm, experiments showed significant enhancement by at least one amino sugar in the ability of most of these bacteria to suppress the caries pathogen. Therefore, our findings demonstrated the mechanism of action by which amino sugars may affect human oral biofilms to promote health.
Topics: Amino Sugars; Biofilms; Dental Caries; Dental Plaque; Saliva; Streptococcal Infections; Streptococcus gordonii; Streptococcus mutans; Symbiosis
PubMed: 30877119
DOI: 10.1128/AEM.00370-19 -
Anaerobe Feb 2019Dental biofilms are complex ecosystems containing many bacterial species that live in mutualistic relationships. These interactions can profoundly affect the virulence...
Dental biofilms are complex ecosystems containing many bacterial species that live in mutualistic relationships. These interactions can profoundly affect the virulence properties of the community. In this study we investigated how the production of gingipains, virulence factors from Porphyromonas gingivalis important in periodontal disease, was affected by other commonly found members of the sub-gingival microbiome. To mimic the subgingival microbiome, multispecies consortia (P. gingivalis, Fusobacterium nucleatum, Actinomyces naeslundii, Streptococus oralis, Streptococcus mitis, Streptococcus gordonii and Streptococcus cristatus, with or without Parvimonas micra) as well as dual species consortia (P. gingivalis with P. micra, S. oralis or F. nucleatum) were constructed and maintained anaerobically in 10% serum for up to seven days. The number of P. gingivalis was determined by plating on Brucella agar and the gingipain specific fluorogenic substrate BikKam-10 was used to investigate gingipain activity. The effect of secreted products from P. micra on gingipain activity was investigated by adding supernatants from P. micra to P. gingivalis cultures. The most prominent secreted proteins in the supernatant were identified using mass spectrometry. P. gingivalis was unable to grow in serum, either alone or in the presence of S. oralis or F. nucleatum. In contrast, with P. micra growth was significantly enhanced and this was associated with an increase in gingipain activity. In the multi-species consortia, the presence of P. micra caused a 13-fold increase in gingipain activity. Exposure of P. gingivalis to supernatants from P. micra for 24 h caused a 3-fold increase in gingipain activity. This effect was reduced by 43% after heat-treatment of the supernatant. Two dimensional gel electrophoresis revealed that several of the most prominent proteins in the P. micra supernatant were glycolytic enzymes. The results from this study suggests that gingipains are produced in response to a P. micra derived signalling molecule that is most likely a protein. This is the first time it has been shown that P. micra can affect P. gingivalis virulence properties. This is likely to be of significance for the development of be of periodontitis since these two microorganisms are often found together in the subgingival biofilm.
Topics: Adhesins, Bacterial; Anaerobiosis; Bacterial Load; Colony Count, Microbial; Culture Media; Cysteine Endopeptidases; Firmicutes; Gingipain Cysteine Endopeptidases; Humans; Microbial Consortia; Microbial Interactions; Porphyromonas gingivalis; Serum; Virulence Factors
PubMed: 30359695
DOI: 10.1016/j.anaerobe.2018.10.007 -
Clinical Nuclear Medicine Nov 2018A 47-year-old man, with a history of anabolic steroid abuse, developed hepatic adenomatosis and multifocal hepatocellular carcinoma. He underwent ultrasound and CT...
A 47-year-old man, with a history of anabolic steroid abuse, developed hepatic adenomatosis and multifocal hepatocellular carcinoma. He underwent ultrasound and CT follow-up, showing multiple solid and fluid hepatic lesions. Consequently, hospitalization was required because of high fever (up to 39°C), weakness, and anorexia. An abdominal CT scan revealed an enlargement of one of the intrahepatic fluid collections. Biochemical and microbiological analyses of a fluid sample showed bilirubin and bile acids as well as Streptococcus cristatus and Enterobacter cloacae. Thus, the patient underwent Tc-trimethylbromo-iminodiacetic acid scintigraphy, demonstrating bile collection in the lesion with a flow from a bile duct.
Topics: Bile; Carcinoma, Hepatocellular; Humans; Liver Neoplasms; Male; Middle Aged; Radionuclide Imaging; Tomography, X-Ray Computed; Ultrasonography
PubMed: 30222677
DOI: 10.1097/RLU.0000000000002272 -
Oral Diseases May 2019Recent advances in the field of molecular microbiology provide an unprecedented opportunity to decipher the vast diversity of the oral microbiome in health and disease.... (Review)
Review
Recent advances in the field of molecular microbiology provide an unprecedented opportunity to decipher the vast diversity of the oral microbiome in health and disease. Here, we provide a contemporary overview of the oral microbiome and the microbiota of early childhood caries (ECC) with particular reference to newer analytical techniques. A MEDLINE search revealed a total of 20 metagenomic studies describing cariogenic microbiomes of ECC, 10 of which also detailed the healthy microbiomes. In addition, seven studies on site-specific microbiomes, focusing on acidogenic and aciduric microbiota of deep-dentinal lesions, were also reviewed. These studies evaluated plaque and saliva of children aged 1.5-11 years, in cohorts of 12-485 individuals. These studies reveal a very rich and diverse microbial communities, with hundreds of different phylotypes and microbial species, including novel species and phyla such as Scardovia wiggsiae, Slackia exigua, Granulicatella elegans, Firmicutes in the plaque biofilms of children with ECC. On the contrary, bacteria such as Streptococcus cristatus, S. gordonii, S. sanguinis, Corynebacterium matruchotii, and Neisseria flavescens were common in plaque biofilm of noncarious, healthy, tooth surfaces in subjects with caries. The review illustrates the immense complexity and the diversity of the human oral microbiota of the cariogenic plaque microbiome in ECC, and the daunting prospect of its demystification.
Topics: Bacteria; Child; Child, Preschool; Dental Caries; Dental Plaque; Humans; Infant; Microbiota; Saliva; Sequence Analysis, DNA; Tooth; Tooth, Deciduous
PubMed: 29969843
DOI: 10.1111/odi.12932