The design of a real-time pcr assay to assess the effect of chemotherapy on gel e and esp genes of e.faecalis in the microbial flora of breast cancer patients

Farnaz Rahbarzare,1,* Farzaneh hosseini,2 Mohaddeseh larypoor,3

1. Department of microbial biotechnology,Islamic Azad University,Tehran North Branch,Tehran,Iran
2. Department of Microbiology, Islamic Azad University, North Tehran Branch,Tehran,Iran
3. Department of Biology, Faculty of Science, Univers ity of Tehran North Branch , Islamic Azad University,Tehran,Iran



Breast cancer is an uncontrolled growth of abnormal cells that occurs in different regions of the breast. it is the most common cancer and the most common cause of cancer death among women in the world. chemotherapy is an effective and non-invasive method for cancer treatment, it shows a variety of side effects such as hair loss, reduced red blood cell count, infection, vomiting, oral ulcers, constipation and reduction of white blood cell count despite all the side effects of this method are not completely clarified. an important challenge to this therapy method, is the effects of chemotherapy on induction of microflora bacteria pathogenesis. the purpose of this study is the investigation of the side effect of the chemotherapy on enterococcus faecalis (a microflora bacteria) virulence genes in breast cancer patients.


To better understand the molecular mechanisms underlying this microflora pathogenesis changes, we have used the real time pcr to analyze gele and esp gene expression in the enterococcus faecalis of three groups samples. in this study, participators were divided into three groups a, b and c. group a included 60 healthy relatives of cancer patients, group b 60 breast cancer patients before chemotherapy treatment, group c breast cancer patients after one chemotherapy period. the biochemical tests needed for the identification and determination of enterococcus faecalis. then total rna was extracted from the stool of all the participators, after that cdna was produced. next, specific primers were designed using primer 3 and oligo 7 software. thus, virulence genes of e. faecalis (gele and esp) were evaluated by real-time pcr. data analysis was done by spss software version 19.


Results showed a statistically significant correlation (p<0.05) over the expression level of gele and esp in group c (patients after one chemotherapy treatment) against group b (patients before chemotherapy treatment) and a (healthy relatives of cancer patients). also, no significant alteration observed in expression level of gele and esp between group a and b.


It seems that breast cancer does not affect the pathogenicity of microflora, but chemotherapy has side effects such as increasing the pathogenicity risk of the microflora of patients; it could change virulence gene expression of microbial flora. these side effects could cause further infections after finishing the chemotherapy of cancer. further gene expression studies could help to better understand of chemotherapy effects on the whole body and mechanisms of patients.


Enterococcus faecalis, virolence factors, esp, gele, syber green i