Isolation and characterization of Priestia megaterium strain NCT22 from human skin microbiome

Abstract

As a part of academic lab in bacteriology, human skin microbiome was sampled and swabbed on to nutrient agar plates. The pure culture was preserved using glycerol stocking in triplicates. This glycerol stocked cultures were revived and used for further morphological and molecular characterization.

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National College Culture Collection Centre
PG & Research Department of Biotechnology and Microbiology
National College, Tiruchirappalli- 620 001, Tamil Nadu, India
1
Isolation and characterization of Priestia megaterium strain NCT22 from human skin
microbiome
Background
As a part of academic lab in bacteriology, human skin microbiome was sampled and swabbed on
to nutrient agar plates. The pure culture was preserved using glycerol stocking in triplicates. This
glycerol stocked cultures were revived and used for further morphological and molecular
characterization.
Work plan
Bergey’s manual was used to determine the lowest possible taxonomic hierarchy and the strain
was commercially outsourced for bidirectional 16S rRNA gene sequencing for species level
resolution.
Results
Strain description: NCT22 grows well in nutrient agar plate at 37°C in 24 hours. Colonies are
small, white, round with smooth edges. Cells are Gram positive, spore forming, non-capsulated
and non-motile rods. Biochemical reaction implies Indole negative, methyl red negative, voges
proskauer
negative and
citrate negative.
Triple Sugar
Iron implies
acid butt and
alkaline slant
with no gas
production.
Catalase
positive and
oxidase positive.

National College Culture Collection Centre
PG & Research Department of Biotechnology and Microbiology
National College, Tiruchirappalli- 620 001, Tamil Nadu, India
2
NCT22 form beta-hemolytic patters in blood agar. The strain NCT22 was sensitive to clindamycin
(4mm), amoxicillin (6mm), Ampicillin (4mm), streptomycin (10mm) and resistance to nystatin.
16S rRNA gene sequencing:
Based on the colony and biochemical characteristics, the strain NCT22 was identified as Priestia
megaterium. NCT22 was 98.69% similar to Priestia megaterium (GenBank accession number:
NR_112636). 16S rRNA gene sequence of NCT22 can be globally accessed through genbank
accession number OQ271423.
The Neighbor-Joining method tree with percentage of replicate trees in which the associated taxa
clustered together in the
bootstrap test (500 replicates)
are shown. The tree is drawn to
scale, with branch lengths in the
same units as those of the
evolutionary distances used to
infer the phylogenetic tree. The
evolutionary distances were
computed using the Maximum
Composite Likelihood method
and are in the units of the number
of base substitutions per site.
This analysis involved 11
nucleotide sequences. All
ambiguous positions were
removed for each sequence pair
(pairwise deletion option). There
were a total of 1316 positions in
the final dataset.
The strain NCT22 was deposited
in National College Culture
Collection Centre (ncccc) and are
freely available for academic and
research purposes. The strain can
be order here www.ncccc.in