List of Articles clbB

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  1 - Study of clbB and clbN genes in E.coli isolates isolated from vegetables irrigated with surface water and urban waste
  Samira Sadeghian Mohsen Zargar shahla Mohammad Ganji
  Objective: One of the factors causing colorectal cancer is infection with a specific strain of Escherichia coli (E.coli) that has a PKS genomic island with two clbB and clbN genes. One of the ways of human bacterial contamination is to consume vegetables irrigated with More

  Objective: One of the factors causing colorectal cancer is infection with a specific strain of Escherichia coli (E.coli) that has a PKS genomic island with two clbB and clbN genes. One of the ways of human bacterial contamination is to consume vegetables irrigated with water contaminated with bacteria. These two genes cause the activation of the message transmission pathway and the DNA mutation and tumorigenesis by producing the toxin Bactin. The main aim of the present study is to investigate clbB and clbN genes in Escherichia coli isolated from vegetables irrigated with surface water and urban waste. Materials and methods: Vegetables irrigated with surface water, well and urban waste were collected from three regions of Tehran. Their E.coli bacteria were isolated and identified and confirmed. Then, PCR test was performed for clbB and clbN genes of all isolated E.coli bacteria. Findings: The obtained microbial and biochemical results confirmed the E.coli bacteria isolated from the investigated vegetables. The molecular results showed that the highest and lowest frequencies for the samples that simultaneously contained both studied genes were related to vegetables irrigated with urban waste and vegetables irrigated with well water (P≤0.05). This result was almost the same for the vegetables of all three studied regions. Conclusion: Considering the high frequency of E.coli bacteria isolated from vegetables irrigated with municipal waste and in order to prevent bacterial infection and consequently colorectal cancer, complete disinfection of vegetables and non-irrigation of vegetables in areas with waste are suggested. Keywords: E.coli, clbB, clbN, Vegetables, Urban waste, Surface water. Manuscript profile
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  2 - Molecular analysis of the genes encoding colibactin production in Klebsiella pneumoniae isolated from raw milk by Multiplex-PCR as an agent for colorectal cancer
  Marziyeh Radaei Alamoli sedigheh mehrabian kumarss amini parisa mobasseri
  Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultatively anaerobic, rod-shaped bacterium.It has traditionally been considered an opportunistic pathogen and is a common cause of nosocomial infections. The pks gene cluster enco More

  Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultatively anaerobic, rod-shaped bacterium.It has traditionally been considered an opportunistic pathogen and is a common cause of nosocomial infections. The pks gene cluster encodes enzymes responsible for the synthesis of colibactin. Colibactin is a genotoxin that has been shown to induce DNA damage and contribute to increased virulence. Colibactin is also strongly suspected of being involved in the development of colorectal cancer. The present study investigated the prevalence of pks, clbN, and clbB genes in Klebsiella pneumoniae isolates. In this study, 220 samples were obtained from raw milk. Then, all samples were cultured in the violet red bile agar and then cultured in blood agar, MacConkey agar, and chocolate agar for bacterial isolation. Biochemical and microbiological tests were performed for confirmation of the bacteria. DNA was extracted from all isolates using a genomic DNA extraction kit. Then multiplex polymerase chain reaction (M-PCR) method was performed using specific primers. It was found that 60 K. pneumonia isolates out of 220 samples (27.27%) were confirmed by standard phenotypic tests. The PCR test indicated that 6 (10%) strains carried clbN and clbB genes. The pks positive K. pneumoniae was more prevalent in our samples. Owing to its pleiotropic effects, colibactin profoundly influences cellular physiology, inducing DNA breaks that lead to senescence or apoptosis. It seems that the identification of the pks positive K. pneumoniae in milk is essential to prevent colorectal cancer. Manuscript profile