مقالات پذیرفته شده در هفتمین کنگره بین المللی زیست پزشکی
Evaluation of anti-biofilm activity of Lactobacillus rhamnosus GG and Nisin on the expression of aap, ica-A and ica-D as biofilm-associated genes of Staphylococcus epidermidis
Evaluation of anti-biofilm activity of Lactobacillus rhamnosus GG and Nisin on the expression of aap, ica-A and ica-D as biofilm-associated genes of Staphylococcus epidermidis
kowsar mansouri,1,*Mohammad Dalvand,2Seyed Ali Mirhosseini,3Hamideh Mahmoodzadeh Hosseini,4
1. New Hearing Technologies Research Center, Clinical Sciences Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran 2. Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran 3. Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Introduction: In the present study, the anti-biofilm activity of Lactobacillus rhamnosus GG and Nisin was
investigated on biofilm-forming abilities of Staphylococcus epidermidis strains and the expression of the biofilm-associated
genes.
Methods: In this study, the standard strain of L. rhamnosus GG (ATCC 53103) and Nisin were used to assess
their anti-microbial and anti-biofilm effects on S. epidermidis (RP62A).
Results: The MIC and MBC analysis showed that Nisin at 256 μg/mL and 512 μg/mL, and L. rhamnosus GG at 1×107 CFU/
mL and 1×108 CFU/mL have anti-microbial activity compared to the negative control respectively. L. rhamnosus GG bacteria
and Nisin inhibited the biofilm formation of S. epidermidis based on optical density of at 570 nm (P <0.001). The relative
mRNA expression of aap, icaA, and icaD genes was significantly reduced compared to the negative control after treating S.
epidermidis with sub-MIC of Nisin (0.44, 0.25 and 0.6 fold, respectively) (P>0.05). In addition, the relative expression of
aap and icaA genes, but not icaD (P>0.05), was significantly lower than the negative control (0.62 and 0.7 fold, respectively)
(P>0.05), after exposure to the sub MIC of L. rhamnosus GG.
Conclusion: Nisin and L. rhamnosus GG exhibit potent activity against biofilm-forming abilities of S. epidermidis and these
agents could be utilized as an anti-biofilm agents against S. epidermidis infections.