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PloS One 2017We describe here a strategy that can distinguish between Staphylococcus species truly present in a clinical sample from contaminating Staphylococcus species introduced...
We describe here a strategy that can distinguish between Staphylococcus species truly present in a clinical sample from contaminating Staphylococcus species introduced during the testing process. Contaminating Staphylococcus species are present at low levels in PCR reagents and colonize lab personnel. To eliminate detection of contaminants, we describe an approach that utilizes addition of sufficient quantities of either non-target Staphylococcal cells (Staphylococcus succinus or Staphylococcus muscae) or synthetic oligonucleotide templates to helicase dependent isothermal amplification reactions to consume Staphylococcus-specific tuf and mecA gene primers such that contaminating Staphylococcus amplification is suppressed to below assay limits of detection. The suppressor template DNA is designed with perfect homology to the primers used in the assay but an internal sequence that is unrelated to the Staphylococcal species targeted for detection. Input amount of the suppressor is determined by a mathematical model described herein and is demonstrated to completely suppress contaminating levels of Staphylococcus while not negatively impacting the appropriate clinical assay limit of detection. We have applied this approach to improve the specificity of detection of Staphylococcus species present in positive blood cultures using a chip-based array that produces results visible to the unaided eye.
Topics: DNA Contamination; DNA, Bacterial; Humans; Nucleic Acid Amplification Techniques; Sensitivity and Specificity; Staphylococcal Infections; Staphylococcus
PubMed: 28225823
DOI: 10.1371/journal.pone.0171915 -
Genome Announcements Jan 2017Staphylococcus succinus subsp. succinus type strain DSM 14617 was isolated from plant and soil inclusions within 25- to 35-million-year-old Dominican amber. The...
Draft Genome Sequence of Staphylococcus succinus subsp. succinus Type Strain DSM 14617, Isolated from Plant and Soil Inclusions within 25- to 35-Million-Year-Old Dominican Amber.
Staphylococcus succinus subsp. succinus type strain DSM 14617 was isolated from plant and soil inclusions within 25- to 35-million-year-old Dominican amber. The complete genome sequence of strain DSM 14617 includes a genome of 2.88 Mb (32.94% G+C content) without any plasmids.
PubMed: 28126945
DOI: 10.1128/genomeA.01521-16 -
Microbes and Infection Dec 2016Drosophila melanogaster is an emerging model system for the study of evolutionary ecology of immunity. However, a large number of studies have used non natural pathogens...
Drosophila melanogaster is an emerging model system for the study of evolutionary ecology of immunity. However, a large number of studies have used non natural pathogens as very few natural pathogens have been isolated and identified. Our aim was to isolate and characterize natural pathogen/s of D. melanogaster. A bacterial pathogen was isolated from wild caught Drosophila spp., identified as a new strain of Staphylococcus succinus subsp. succinus and named PK-1. This strain induced substantial mortality (36-62%) in adults of several laboratory populations of D. melanogaster. PK-1 grew rapidly within the body of the flies post infection and both males and females had roughly same number of colony forming units. Mortality was affected by mode of infection and dosage of the pathogen. However mating status of the host had no effect on mortality post infection. Given that there are very few known natural bacterial pathogens of D. melanogaster and that PK-1 can establish a sustained infection across various outbred and inbred populations of D. melanogaster this new isolate is a potential resource for future studies on immunity.
Topics: Animals; Drosophila melanogaster; Female; Male; Staphylococcus; Survival Analysis
PubMed: 27492855
DOI: 10.1016/j.micinf.2016.07.008 -
Genome Announcements Jun 2016Here, we report the draft genome sequence of Staphylococcus succinus strain CSM-77. This moderately halophilic bacterium was isolated from the surface of a halite sample...
Here, we report the draft genome sequence of Staphylococcus succinus strain CSM-77. This moderately halophilic bacterium was isolated from the surface of a halite sample obtained from a Triassic salt mine.
PubMed: 27284152
DOI: 10.1128/genomeA.00532-16 -
Acta Biochimica Polonica 2016Historic buildings are constantly being exposed to numerous climatic changes such as damp and rainwater. Water migration into and out of the material's pores can lead to...
Historic buildings are constantly being exposed to numerous climatic changes such as damp and rainwater. Water migration into and out of the material's pores can lead to salt precipitation and the so-called efflorescence. The structure of the material may be seriously threatened by salt crystallization. A huge pressure is produced when salt hydrates occupy larger spaces, which leads at the end to cracking, detachment and material loss. Halophilic microorganisms have the ability to adapt to high salinity because of the mechanisms of inorganic salt (KCl or NaCl) accumulation in their cells at concentrations isotonic to the environment, or compatible solutes uptake or synthesis. In this study, we focused our attention on the determination of optimal growth conditions of halophilic microorganisms isolated from historical buildings in terms of salinity, pH and temperature ranges, as well as biochemical properties and antagonistic abilities. Halophilic microorganisms studied in this paper could be categorized as a halotolerant group, as they grow in the absence of NaCl, as well as tolerate higher salt concentrations (Staphylococcus succinus, Virgibacillus halodenitrificans). Halophilic microorganisms have been also observed (Halobacillus styriensis, H. hunanensis, H. naozhouensis, H. litoralis, Marinococcus halophilus and yeast Sterigmatomyces halophilus). With respect to their physiological characteristics, cultivation at a temperature of 25-30°C, pH 6-7, NaCl concentration for halotolerant and halophilic microorganisms, 0-10% and 15-30%, respectively, provides the most convenient conditions. Halophiles described in this study displayed lipolytic, glycolytic and proteolytic activities. Staphylococcus succinus and Marinococcus halophilus showed strong antagonistic potential towards bacteria from the Bacillus genus, while Halobacillus litoralis displayed an inhibiting ability against other halophiles.
Topics: Antibiosis; Bacillus; Construction Materials; Environmental Microbiology; Halobacteriales; Hydrogen-Ion Concentration; Staphylococcus
PubMed: 26894235
DOI: 10.18388/abp.2015_1171 -
International Journal of Food... Nov 2015In Italy, fermented sausages (called "salami") are consumed in large quantities. Salami samples from a local meat factory in the area of Torino were analyzed at 0, 3, 7,...
In Italy, fermented sausages (called "salami") are consumed in large quantities. Salami samples from a local meat factory in the area of Torino were analyzed at 0, 3, 7, 30 and 45 days of ripening. Swab samples from the production environment were also collected at the beginning of the experiment. The diversity of metabolically active microbiota occurring during the natural fermentation of salami was evaluated by using RT-PCR-DGGE coupled with RNA-based pyrosequencing of the 16S rRNA gene. A culture-dependent approach was also applied to identify and characterize isolated Staphylococcaceae and LAB populations. Staphylococcus succinus, Staphylococcus xylosus and Lactobacillus sakei were the species most frequently isolated during the maturation time. Rep-PCR analysis showed that S. succinus and S. xylosus isolated from swabs and salami samples clustered together, suggesting possible contamination during the production process. RT-PCR-DGGE and rRNA-based pyrosequencing showed that the metabolically active populations were dominated by S. succinus, Lb. sakei and Leuconostoc carnosum. In this specific case study, only a few species belonging to Staphylococcaceae, Lactobacillaceae and Leuconostocaceae may be metabolically active and contribute to determine the final characteristics of the products.
Topics: Biodiversity; Fermentation; Food Microbiology; Gram-Positive Bacteria; Italy; Meat Products; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Time
PubMed: 25724303
DOI: 10.1016/j.ijfoodmicro.2015.01.016