Sex-Pheromone System and Plasmid Transfer in Enterococcus feacalis
Jawad Kadhum Tarrad Al-Khafaji
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Keywords : Sex-Pheromone System ,Plasmid Transfer in Enterococcus
| Medical Journal of Babylon 8:1 , 2014 |
doi:1812-156X-8-1 |
| Published :2011 |
|
Abstract
Pheromone-inducible plasmid transfer is an important mechanism for dissemination of antibiotic resistance
and virulence factors in these organisms. Plasmid-free strains of Enterococcus faecalis secrete at least half
a dozen peptide sex pheromone-probably many more-that induce a mating response by potential donor
strains carrying members of specific families of conjugative plasmids. The response is associated with
synthesis of surface proteins that facilitates formation of donor-recipient mating aggregates. When a
recipient acquires a given plasmid , the corresponding pheromone becomes shutdown or masked. Although
the structure of at least five of these peptides has been determined.
Introduction
Gene Transfer Among Enterococci:
Transfer of genes among genera
of bacteria occurring in two
mechanisms; one mechanism,
transfer of DNA within bacterial
cells by transposons. The transposons
are pieces of DNA that move readily
from one site on the bacterial
chromosome to another site, or they
transfer to plasmid. The transposons are
not capable of independent replication,
they replicate as part of recipient DNA.
They can code for drug resistance
enzymes, toxins production or variety of
metabolic activities. Another mechanism
,transfer of genetic information from one
bacterium to another. These transfer can
occur by three methods: conjugation,
transduction and transformation [1].
Enterococci posses ability to horizontal
exchange of genetic materials among
themselves and with other gram-positive
bacterial genera [2]. The exchange of
genetic elements of Enterococcus
feacalis by conjugation is studied during
twentieth century in deeply. The first
convincing evidence for the existence of
plasmid-mediated gene transfer in this
organism was obtained by Tomura et al.
,1973[3] and by Jacob and Hobbs
,1974[4]. At least three conjugative
systems have been reported in
Enterococus feacalis, ( i )The
conjugative system occurs in wide
range of related bacterial genera(braodhost
range plasmids). The plasmids can
transfer among enteroccoci species and
with other genera such as many species
of streptococci, Staphylococcus aureus,
Lactobacillus species, Bacillus subtilis,
Listeria monocytogenes and others. The
transfer of this type is largely dependent
on forced cell contact on membrane
filter and is very inefficient in broth .
The transfer of plasmid is lower than(10-
4-10-5 per donor cell) gene transfer by
pheromone induction[5]. (ii)The transfer
of plasmids by transposon mechanism
T
Materials and methods
Study was done in Hilla in privet clinic.
Between 2006-2008 / Babylon Province.
Patients were selected according to these
criteria :
Patient al either sex more than 50 years
& they fulfilling the American collage of
Rhenmatology (ACR) criteria of clinical,
laboratory and radiographic findings[6],
those patients were diagnosed with
primary osteoarthitis with lequesns score
in the range of ( 10-18 ) [7]& those
patients can come for regular visit. 150
patient were included in the study ,30
patients were excluded because either
they had arthritis due to other cause like
Rheumatoid arthritis or have renal or
hepatic dysfunction or other serious
medical illness ( Sever Ischemic heart
Disease. Or heart failure.
The first screening visit , Patient medical
history was taken & clinical assessment
was done . The knee its were examined
by local examination & specific
parameter for assessing the severity
subjectivity as well as objectivity.
All patients were asked to guard the
severity of pain based on visual analogue
scale ( VAS) ranging from no pain at
bottom of the scale to unbearable pain at
the top of 100 mm colored scale. The
other variable in the scale were mild ,
modrate and sever pain separated by 20
mm. [8] , lequesnes index ( Table 1)
Results
This study was design as compared
study between [two ] groups group one
and two both include 60 patients for
each ,the mean age of group [1] was 57
years and group [2] was 58 years.
Sex ratio ,group [1],51 female and 9
male and group [2] 50 female and 10
male table [1].
The functional score was recorded for
both groups from the start of the study
and at 2 months interval to the end of the
study ,in group [1] the improvement was
30-/+ 5 while group [2] was 25-/+5 at
the end of the study table [2].
The visual analogue scale for both
groups were recorded at the start and 2
months interval to the end of the study
,the improvement from 70-/+6 to 35 in
group [1] where the improvement in
group [2] was from 72 to 50 table [3]
The radiological score ,there was no
difference between both groups during
the study period and no difference in
progress of osteoarthritis radiological
features. table[4].
To compare the use of additive drug
[paracetomol ] by the numbers of the
tablets [more than 10 tablets] per week
,in group one 41 patients had recorded to
use the drug while group [2] 38 patients
were use the drug. table[5] .
The patient and physician assessment
during the study the difference was more
Discussions
Osteoarthritis is a disease of progressive
cartilage damage seen mostly after the
age of 40s years ,
The pain may arise from synovial
inflammation or periosteal nerve
stimulation ,previously NSIADs widely
used for relieving the pain in
osteoarthritis but mostly there is good
present of patients that stop drug
because adverse effect that related to the
therapy and the older people with
multiple clinical problem that NSIADs
lead to more adverse effect ,due to this
fact there was new drugs emergence that
would work to reduce patients symptoms
,and they act to regenerate cartilage and
act as anti inflammatory with low risk
for patients[11] this supported also by
study of Alekseeva et al [12]
The glucosamine and chondrotin
combination has been sued in all over
the world for knee osteoarthritis and
many studies work for that, it used as
nutritional supplements for knee
osteoarthritis[13].
In this study combination of
glucosamine and chondrotin has work
well as compare with treatment by
melocexam drug ,the pain score was
assessed by the visual scale ,this
parameter showed progressive
improvement over the period of drug
therapy with maximum benefit at 4
months point while the other group show
rapid improvement at 2 months point but
then no more improvement after that
point ,when compare with Bourgeois et
al [14], 3 months trial of 1200 mg of
both combination in single or divided
doses its showed that decrease of
lequense index and spontaneous joint
pain score versus placebo [p<0.1]
The lequesne index that assess the
functional score the functional mobility
of the joints depending on the daily
activity ,it showed mark improvement
than the other group at 2-4 months and
such result was documented in other
studies e.g Muller et al [ 14 ] ,Noaek
et al[ 15 ] and they found that this
index to be a sensitive indicator of the
improvement, Muller and collogues [16]
in short term study [4 weeks ] study to
compare this drug versus ibuprofen
showed that its effective like ibuprofen
and better tolerated [p<0.1]
The radiological score change in this
study show no difference between 2
groups during the this study period ,they
not correlated with patients symptoms
many patients show functional disability
that not correlated with X ray finding .
And only 6% show adverse effect while
35% eboburfen qroup show adverse
effect mainly gastrointestinal, in our
study CS group show 10% show adverse
Conclusions
N/A
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