scholarly journals Cat Scratch Disease: the Rare Role ofAfipia felis

1998 ◽  
Vol 36 (9) ◽  
pp. 2499-2502 ◽  
Author(s):  
Michael Giladi ◽  
Boaz Avidor ◽  
Yehudith Kletter ◽  
Suzy Abulafia ◽  
Leonard N. Slater ◽  
...  
Keyword(s):  
Lymph Node ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Bartonella Henselae ◽  
16S Rrna Gene Sequencing ◽  
Fatty Acid Analysis ◽  
Rrna Gene ◽  
Cat Scratch Disease ◽  
Rrna Gene Sequencing

Since its isolation in 1988, Afipia felis has been associated with cat scratch disease (CSD) in only one report and its role in CSD has been questioned. We have cultured A. felisfrom a lymph node of a patient with CSD. 16S rRNA gene sequencing, DNA relatedness studies, fatty acid analysis, and PCR of the A. felis ferredoxin gene showed that the isolate is identical to the previously reported A. felis isolate. To determine the role of A. felis in CSD, PCR of the 16S rRNA gene followed by hybridizations with specific probes were performed with lymph node specimens from CSD patients. All 32 specimens tested positive forBartonella henselae and negative for A. felis. We conclude that A. felis is a rare cause of CSD. Diagnostic tests not conducive to the identification of A. felis might cause the diagnosis of CSD due to A. felis to be missed.

scholarly journals LACK OF EVIDENCE FOR A VIABLE MICROBIOTA IN MURINE AMNIOTIC FLUID

2021 ◽  
Author(s):  
Andrew D. Winters ◽  
Roberto Romero ◽  
Jonathan M Greenberg ◽  
Jose Galaz ◽  
Zachary D Shaffer ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Amniotic Fluid ◽  
16S Rdna ◽  
16S Rrna Gene Sequencing ◽  
Late Gestation ◽  
Rrna Gene ◽  
Rrna Gene Sequencing ◽  
The 16S Rrna Gene

The existence of an amniotic fluid microbiota (i.e., a viable microbial community) in mammals is controversial. Its existence would require a fundamental reconsideration of the role of intra-amniotic microbes in fetal development and pregnancy outcomes. In this study, we determined whether the amniotic fluid of mice harbors a microbiota in late gestation. Bacterial profiles of amniotic fluids located proximally or distally to the cervix were characterized through quantitative real-time PCR, 16S rRNA gene sequencing, and culture (N=21 mice). These profiles were compared to those of technical controls for background DNA contamination. The load of 16S rDNA in the amniotic fluid exceeded that in controls. Additionally, the 16S rDNA profiles of the amniotic fluid differed from those of controls, with Corynebacterium tuberculostearicum being differentially more abundant in amniotic fluid profiles; however, this bacterium was not cultured. Of the 42 total bacterial cultures of amniotic fluids, only one yielded bacterial growth – Lactobacillus murinus. The 16S rRNA gene of this common murine-associated bacterium was not detected in any amniotic fluid sample, suggesting it did not originate from the amniotic fluid. No differences in 16S rDNA load, 16S rDNA profile, or bacterial culture were observed between amniotic fluids located proximal and distal to the cervix. Collectively, these data show that, although there is a modest DNA signal of bacteria in murine amniotic fluid, there is no evidence that this signal represents a viable microbiota. These findings refute the proposed role of amniotic fluid as a source of microorganisms for in utero colonization.

scholarly journals The Role of 16S rRNA Gene Sequencing in Confirmation of Suspected Neonatal Sepsis

2015 ◽  
Vol 62 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Somaia El Gawhary ◽  
Mervat El-Anany ◽  
Reem Hassan ◽  
Doaa Ali ◽  
El Qassem El Gameel
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Neonatal Sepsis ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Rrna Gene Sequencing

scholarly journals Chryseobacterium taiwanense sp. nov., isolated from soil in Taiwan

2006 ◽  
Vol 56 (8) ◽  
pp. 1771-1776 ◽  
Author(s):  
Chun-Ju Tai ◽  
Hsiao-Ping Kuo ◽  
Fwu-Ling Lee ◽  
Han-Ken Chen ◽  
Akira Yokota ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Dna Hybridization ◽  
Sequence Similarity ◽  
16S Rrna Gene Sequencing ◽  
Fatty Acid Analysis ◽  
Phenotypic Characterization ◽  
Rrna Gene ◽  
Gene Sequence Analysis ◽  
Rrna Gene Sequencing

Among a large collection of Taiwanese soil isolates, a novel Gram-negative, rod-shaped, non-spore-forming, yellow-pigmented bacterial strain, Soil-3-27T, was isolated from farmland soil in Wu-Feng, Taiwan. The isolate was subjected to a polyphasic study including 16S rRNA gene sequencing, DNA–DNA hybridization, fatty acid analysis and comparative phenotypic characterization. The 16S rRNA gene sequence analysis indicated that the organism belongs to the genus Chryseobacterium. The organism contains menaquinone MK-6 as the predominant isoprenoid quinone and 15 : 0 iso (43 %), 17 : 1 isoω9c (17.5 %) and 17 : 0 iso 3-OH (16.6 %) as the major fatty acids. Phylogenetically, the closest relatives of strain Soil-3-27T are Chryseobacterium daecheongense, Chryseobacterium defluvii and Chryseobacterium taichungense with 96.7–97.2 % sequence similarity. DNA–DNA hybridization showed relatedness values of 8.5–24.2 % with these species. The DNA G+C content is 36.8 mol%. Strain Soil-3-27T is clearly distinguishable from other Chryseobacterium species and represents a novel species, for which the name Chryseobacterium taiwanense sp. nov. is proposed. The type strain is strain Soil-3-27T (=BCRC 17412T=IAM 15317T=LMG 23355T).

Screening and Molecular Characterization of Cellulase Producing Actinobacteria from Litchi Orchard

2019 ◽  
Vol 13 (1) ◽  
pp. 90-101
Author(s):  
Sanju Kumari ◽  
Utkarshini Sharma ◽  
Rohit Krishna ◽  
Kanak Sinha ◽  
Santosh Kumar
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Molecular Characterization ◽  
Biochemical Characterization ◽  
Evolutionary Relationship ◽  
Gene Sequencing ◽  
Cellulase Activity ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Rrna Gene Sequencing

Background: Cellulolysis is of considerable economic importance in laundry detergents, textile and pulp and paper industries and in fermentation of biomass into biofuels. Objective: The aim was to screen cellulase producing actinobacteria from the fruit orchard because of its requirement in several chemical reactions. Methods: Strains of actinobacteria were isolated on Sabouraud’s agar medium. Similarities in cultural and biochemical characterization by growing the strains on ISP medium and dissimilarities among them perpetuated to recognise nine groups of actinobacteria. Cellulase activity was measured by the diameter of clear zone around colonies on CMC agar and the amount of reducing sugar liberated from carboxymethyl cellulose in the supernatant of the CMC broth. Further, 16S rRNA gene sequencing and molecular characterization were placed before NCBI for obtaining recognition with accession numbers. Results: Prominent clear zones on spraying Congo Red were found around the cultures of strains of three groups SK703, SK706, SK708 on CMC agar plates. The enzyme assay for carboxymethylcellulase displayed extra cellulase activity in broth: 0.14, 0.82 and 0.66 µmol mL-1 min-1, respectively at optimum conditions of 35°C, pH 7.3 and 96 h of incubation. However, the specific cellulase activities per 1 mg of protein did not differ that way. It was 1.55, 1.71 and 1.83 μmol mL-1 min-1. The growing mycelia possessed short compact chains of 10-20 conidia on aerial branches. These morphological and biochemical characteristics, followed by their verification by Bergey’s Manual, categorically allowed the strains to be placed under actinobacteria. Further, 16S rRNA gene sequencing, molecular characterization and their evolutionary relationship through phylogenetics also confirmed the putative cellulase producing isolates of SK706 and SK708 subgroups to be the strains of Streptomyces. These strains on getting NCBI recognition were christened as Streptomyces glaucescens strain SK91L (KF527284) and Streptomyces rochei strain SK78L (KF515951), respectively. Conclusion: Conclusive evidence on the basis of different parameters established the presence of cellulase producing actinobacteria in the litchi orchard which can convert cellulose into fermentable sugar.

scholarly journals Much ado about nothing? Off-target amplification can lead to false-positive bacterial brain microbiome detection in healthy and Parkinson’s disease individuals

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Janis R. Bedarf ◽  
Naiara Beraza ◽  
Hassan Khazneh ◽  
Ezgi Özkurt ◽  
David Baker ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
False Positive ◽  
Gene Sequencing ◽  
Bacterial Biomass ◽  
16S Rrna Gene Sequencing ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Rrna Gene Sequencing

Abstract Background Recent studies suggested the existence of (poly-)microbial infections in human brains. These have been described either as putative pathogens linked to the neuro-inflammatory changes seen in Parkinson’s disease (PD) and Alzheimer’s disease (AD) or as a “brain microbiome” in the context of healthy patients’ brain samples. Methods Using 16S rRNA gene sequencing, we tested the hypothesis that there is a bacterial brain microbiome. We evaluated brain samples from healthy human subjects and individuals suffering from PD (olfactory bulb and pre-frontal cortex), as well as murine brains. In line with state-of-the-art recommendations, we included several negative and positive controls in our analysis and estimated total bacterial biomass by 16S rRNA gene qPCR. Results Amplicon sequencing did detect bacterial signals in both human and murine samples, but estimated bacterial biomass was extremely low in all samples. Stringent reanalyses implied bacterial signals being explained by a combination of exogenous DNA contamination (54.8%) and false positive amplification of host DNA (34.2%, off-target amplicons). Several seemingly brain-enriched microbes in our dataset turned out to be false-positive signals upon closer examination. We identified off-target amplification as a major confounding factor in low-bacterial/high-host-DNA scenarios. These amplified human or mouse DNA sequences were clustered and falsely assigned to bacterial taxa in the majority of tested amplicon sequencing pipelines. Off-target amplicons seemed to be related to the tissue’s sterility and could also be found in independent brain 16S rRNA gene sequences. Conclusions Taxonomic signals obtained from (extremely) low biomass samples by 16S rRNA gene sequencing must be scrutinized closely to exclude the possibility of off-target amplifications, amplicons that can only appear enriched in biological samples, but are sometimes assigned to bacterial taxa. Sequences must be explicitly matched against any possible background genomes present in large quantities (i.e., the host genome). Using close scrutiny in our approach, we find no evidence supporting the hypothetical presence of either a brain microbiome or a bacterial infection in PD brains.

scholarly journals Gut microbiota accelerates cisplatin-induced acute liver injury associated with robust inflammation and oxidative stress in mice

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Shenhai Gong ◽  
Yinglin Feng ◽  
Yunong Zeng ◽  
Huanrui Zhang ◽  
Meiping Pan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
16S Rrna ◽  
Gut Microbiota ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Metabolomic Analysis ◽  
Rrna Gene Sequencing ◽  
And Oxidative Stress

Abstract Background Gut microbiota has been reported to be disrupted by cisplatin, as well as to modulate chemotherapy toxicity. However, the precise role of intestinal microbiota in the pathogenesis of cisplatin hepatotoxicity remains unknown. Methods We compared the composition and function of gut microbiota between mice treated with and without cisplatin using 16S rRNA gene sequencing and via metabolomic analysis. For understanding the causative relationship between gut dysbiosis and cisplatin hepatotoxicity, antibiotics were administered to deplete gut microbiota and faecal microbiota transplantation (FMT) was performed before cisplatin treatment. Results 16S rRNA gene sequencing and metabolomic analysis showed that cisplatin administration caused gut microbiota dysbiosis in mice. Gut microbiota ablation by antibiotic exposure protected against the hepatotoxicity induced by cisplatin. Interestingly, mice treated with antibiotics dampened the mitogen-activated protein kinase pathway activation and promoted nuclear factor erythroid 2-related factor 2 nuclear translocation, resulting in decreased levels of both inflammation and oxidative stress in the liver. FMT also confirmed the role of microbiota in individual susceptibility to cisplatin-induced hepatotoxicity. Conclusions This study elucidated the mechanism by which gut microbiota mediates cisplatin hepatotoxicity through enhanced inflammatory response and oxidative stress. This knowledge may help develop novel therapeutic approaches that involve targeting the composition and metabolites of microbiota.

scholarly journals Comparison between 16S rRNA and shotgun sequencing data for the taxonomic characterization of the gut microbiota

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francesco Durazzi ◽  
Claudia Sala ◽  
Gastone Castellani ◽  
Gerardo Manfreda ◽  
Daniel Remondini ◽  
...  
Keyword(s):  
16S Rrna ◽  
Gut Microbiota ◽  
16S Rrna Gene ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Shotgun Sequencing ◽  
Rrna Gene ◽  
Metagenomic Sequencing ◽  
Experimental Conditions ◽  
Rrna Gene Sequencing

AbstractIn this paper we compared taxonomic results obtained by metataxonomics (16S rRNA gene sequencing) and metagenomics (whole shotgun metagenomic sequencing) to investigate their reliability for bacteria profiling, studying the chicken gut as a model system. The experimental conditions included two compartments of gastrointestinal tracts and two sampling times. We compared the relative abundance distributions obtained with the two sequencing strategies and then tested their capability to distinguish the experimental conditions. The results showed that 16S rRNA gene sequencing detects only part of the gut microbiota community revealed by shotgun sequencing. Specifically, when a sufficient number of reads is available, Shotgun sequencing has more power to identify less abundant taxa than 16S sequencing. Finally, we showed that the less abundant genera detected only by shotgun sequencing are biologically meaningful, being able to discriminate between the experimental conditions as much as the more abundant genera detected by both sequencing strategies.

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