Abd El-Lattief et al., 2020
(1) and S .1,4, [5], 12:i:-.(1) (Table 4 and figure 2). O'
yield1000-bp amplicon with conventional PCR. These
data suggest that S. 1, 4, [5], 12:i:- is a monophasic variant
reported that within the flagellin gene cluster of
Salmonella, S. Typhimurium carries a conserved IS200
insertion sequence located downstream of the flagellin N-
methylase gene (fliB) and upstream of the flagellar
biosynthesis sigma factor gene (fliA). In the present study
ten strains yield positive result with fliC , fljB1,2 and fliB/
IS200 were biphasic Salmonella Typhimurium meanwhile
3 strains harbored the fliC and fliB/ IS200 were
monophasic strains S 1, 4,[5],12:i:- (Table 6) .
During recent years the cost of sequencing has been
reduced dramatically making sequencing based typing
more attractive. Some studies have reported DNA
sequence for flagellin gene (Silverman, 1979; Joys, 1985
and De Vries, 1998). As in 2016, fliC sequence (partial
coding sequence) has reported in GenBank with accession
no DQ095491. This study reported sequencing of fliC
gene for two strains S. Typhimurium and monophasic
variant S 1, 4,[5],12:i:- with accession no (Mk103394) and
(Mk103395), respectively.
expressed in uncommon serotypes such as Aberdeen,
Bergen, and Kedougou. The structural flagellin gene fliC
was present in all isolates of serovars Typhimurium and
Kentucky (full length) and in all isolates of serovars
Heidelberg, Hadar, and Enteritidis (partial length)
Most S. enterica serovar Typhimurium possess two
different flagellin proteins, including FliC (phase 1) and
FljB (phase 2), which are encoded by the genes fliC and
confirm the absence of 2nd phase antigen. A real- time
PCR assay was used to differentiate S. Typhimurium
monophasic variants from biphasic S. Typhimurium and
Fifteen isolates are positive for fljB1,2 S.
Typhimurium (10), S. Paratyphi A(1) , S. Paratyphi B(1) ,
S. Newport (1) and S. Virginia (2) (Table 5 and figure 3).
This result agree with that published by Bugarel et al.
(2012) who reported that the second gene codes for the
phase 2 flagellar antigen fljB1,2 is present in S.
Typhimurium and other serovars such as S. Coeln, S.
Haifa, S. Heidelberg, S. Paratyphi B, S. Saintpaul and S.
Stanley. This marker is absent in monophasic S.
Protein sequence is the practical process of
determining the amino acid sequence of all or part of
protein or peptide. About 500 naturally occurring amino
acids are known, 20 only appear in the genetic code there
Typhimurium.
Two
serologically
identified
S.
are termed as codons are always 3 Base pairs
Typhimurium strains no. 55 ,56 don’t possess fljB1,2 that
could be explained by repeat phase inverted method leads
to formation of flakes which may lead to misidentification
or wrongly identified strains.
(nucleotides). In this study, amino acid sequence were
applied for the fliC gene. In the location 14-19 sequence
TNGKVT was found, which is similar to sequences coded
in GenBank with accession no. CP024619, LT795114,
CP014979, but in other sequences reported in GenBank
with accession no. CP026700, CP021462, CP028199
glutamic acid was found between GK with amino acid
sequence TNGEKVT (Figure 5).
In this study, the amino acid threonine was absent at
position 24 in S. Typhimurium Egy1 and S. Typhimurium
Egy2, which is similar to sequences recorded in GenBank
with accession no. CP014979, CP014967. While the result
disagreed with sequences coded in GenBank with
accession number CP007581 and DQ09549 which have
threonine at position 24 between glycine and alanine.
At position 60-65 found amino acid sequence
AGVTGT in S. Typhimurium Egy1 and S. Typhimurium
Egy2, but in sequence coded in GenBank with accession
no. LN999997 amino acid alanine at positin 65 between
glysine and threonine was found. Alignments show highly
degree of identity. There are greater than 98% amino acid
sequence identity (Figures 6 and 7). This is according to
Flagellar phase variation is formed by inversion of
the genetic region called the H segment, which have the
hin gene encoding for DNA invertase and the promoter for
the fljB gene. The fljB constitutes an operon with the fljA
gene, which encodes a negative regulator of fliC
expression. FljA binds to the operator region of FliC
mRNA and inhibits its translation, leading to the rapid
degradation of FliC mRNA. When the H segment is in the
“on” state, both fljB and fljA are transcribed, lead to
synthesis of phase 2 flagellin and inhibition of phase 1
flagellin. However, when the H segment is switched to the
“off” state, neither fljB nor fljA are transcribed, resulting in
The location of IS200 between the genes fliA and
fliB can be used as a specific marker for S. Typhimurium.
The amplicon sizes from the fliA–fliB intergenic regions
from S. Typhimurium and other serovars were expected to
be 1000 and 250 bp, respectively. TaqMan real-time PCR
could successfully detected S. 1, 4, [5], 12:i:- isolates that
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