Characterization of meconium-associated microbiota by cpn60-based microbiome profiling underscores the need for robust negative controls in the study of low microbial biomass samples

2020 ◽  
Vol 223 (6) ◽  
pp. 967
Author(s):  
S.J. Dos Santos ◽  
Z. Pakzad ◽  
C. Elwood ◽  
A. Albert ◽  
J.E. Hill ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Negative Controls ◽  
Microbiome Profiling

Expression and characterization of a lysine rich protein in cow milk

2018 ◽  
Author(s):  
Xin Ma ◽  
Li Su ◽  
Peng Zhang ◽  
Sheng Zhang ◽  
Bo Tang ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Amino Acid ◽  
Expression Vector ◽  
Cow Milk ◽  
Specific Expression ◽  
Mammary Gland Tissue ◽  
Gland Tissue ◽  
Negative Controls ◽  
Mammary Gland Expression

The lysine is considered as the most important essential amino acid, because it is the most limiting in the cereals grains. In this study, a lysine-rich (LR) gene, and the expression vector pcDNA3.1-LR and pBC1-LR were constructed. The LR was expressed in 293T cells driven by the vector pcDNA3.1-LR and checked by RT-PCR and WB. The mammary gland tissue-specific expression vector carrying the LR was injected directly into the lactating mammary glands of cows and the milk samples were checked by a complete amino acid analysis. The results showed that the LR protein was expressed successfully in cells and in cow milk; the expression of LR lasted for 6 d, and the lysine level of the injection group was significantly higher than that of negative controls (p Lass Than 0.05). This study provide a better understanding of how mammary gland expression systems increase the lysine content of milk that can be applied to transgenic dairy cow.

scholarly journals Characterization of Shedding Patterns of Porcine Circovirus Types 2a and 2b in Experimentally Inoculated Mature Boars

2008 ◽  
Vol 20 (6) ◽  
pp. 725-734 ◽  
Author(s):  
Darin M. Madson ◽  
Sheela Ramamoorthy ◽  
Chris Kuster ◽  
Narinder Pal ◽  
Xiang-Jin Meng ◽  
...  
Keyword(s):  
Sperm Morphology ◽  
Porcine Circovirus ◽  
Serum Samples ◽  
Treatment Groups ◽  
Swine Pathogen ◽  
Polymerase Chain ◽  
Swine Herds ◽  
Negative Controls ◽  
Group 1

Porcine circovirus-2 (PCV-2) is an economically important swine pathogen and causes PCV-associated disease (PCVAD) in pigs worldwide. Currently, 2 genotypes of PCV-2, PCV-2a and −2b, are circulating in U.S. swine herds. The objectives of the current study were to evaluate the amount of PCV-2 DNA present in semen over time, compare and correlate incidence and amount of PCV-2 present in semen samples to that present in serum samples and blood swabs, and determine if there are differences in shedding patterns between PCV-2a and −2b. Fifteen 7-month-old PCV-2-naïve Landrace boars ( Sus scrofa) were randomly allocated to 3 treatment groups. The boars in group 1 ( n = 3) served as negative controls, and those in groups 2 ( n = 6) and 3 ( n = 6) were intranasally and intramuscularly inoculated with PCV-2a and −2b, respectively. Semen, serum, and blood swab samples were collected up to 90 days postinoculation (DPI), and necropsies were performed on DPI 23,48, and 90. Larger quantities of both PCV-2a and − 2b DNA were detected earlier in serum and blood swab samples than in raw semen of experimentally inoculated boars. The incidence and duration of presence of PCV-2 DNA in semen varied among boars; however, intermittent shedding was not observed. In all sex glands, PCV-2 DNA was detected by polymerase chain reaction; however, PCV-2 antigen was not detected by immunohistochemistry, and PCV-2 had no effect on sperm morphology. Differences in shedding patterns between PCV-2a and −2b were not observed under the study conditions.

scholarly journals Biochemical and Molecular Characterization of 18 Agrobacterium vitis Isolates

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 439E-439
Author(s):  
Fokar Mohamed ◽  
Richard Durham
Keyword(s):  
Culture Collection ◽  
Phenotypic Characterization ◽  
Polymorphism Analysis ◽  
Detailed Knowledge ◽  
Agrobacterium Vitis ◽  
Biochemical Tests ◽  
Causal Organism ◽  
Dna Plasmid ◽  
Negative Controls

Agrobacterium vitis is the causal organism of crown gall in grapevine. Infection is particularly severe in areas that experience winter damage to vines. Improving resistance to A. vitis will require a detailed knowledge about this organism. In this study, 18 grapevine isolates of A. vitis were collected from different locations near Lubbock, Texas. Isolates were subjected to a phenotypic characterization using 12 biochemical tests, including production of alkali from L-tartrate, production of 3-ketolactose, utilization of citrate, and others. Previously characterized isolates of A. vitis and A. tumefaciens obtained from the American Type Culture Collection served as positive and negative controls in these assays. Isolates were also evaluated for host range, tumor morphology, and opine utilization, and were compared at the molecular level by restriction fragment length polymorphism analysis of the oncogenic regions of the T-DNA plasmid. Although all isolates were able to metabolize tartrate and grow on Roy–Sasser media, there was much variability based on other tests. Twelve of 18 isolates were able to utilize octopine as a sole carbon source. All isolates tested thus far have been pathogenic on tomato and tests on grapevines are underway.

scholarly journals Development of a robust protocol for the characterization of the pulmonary microbiota

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nathan Dumont-Leblond ◽  
Marc Veillette ◽  
Christine Racine ◽  
Philippe Joubert ◽  
Caroline Duchaine
Keyword(s):  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Validity Of Results ◽  
Healthy Human ◽  
Bacterial Dna ◽  
Starting Point ◽  
Sampling Procedures ◽  
Negative Controls ◽  
The Impact

AbstractThe lack of methodological standardization diminishes the validity of results obtained and the conclusions drawn when studying the lung microbiota. We report the validation of a complete 16S rRNA gene amplicon sequencing workflow, from patient recruitment to bioinformatics, tailored to the constrains of the pulmonary environment. We minimize the impact of contaminants and establish negative controls to track and account for them at every step. Enzymatic and mechanical homogenization combined to commercially available extraction kits allow for a fast and reliable extraction of bacterial DNA. The DNA extraction kits have a significant impact on the bacterial composition of the controls. The bacterial signatures of extracted cancerous and healthy human tissues from 5 patients are highly distinguishable from methodological controls. Our work expands our understanding of low microbial burdened environments analysis. This article is to be a starting point towards methodological standardization and the implementation of proper sampling procedures in the study of lung microbiota.

Sign in / Sign up

Export Citation Format

Share Document