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


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.


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)


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


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




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