Although what unifies the carcinogenic microorganisms has not been determined by multiple studies, the role of bacteria in the development of neoplasms has not been properly elucidated. In this review, we discuss links between the bacterial species and cancer, with focus on immune responses for the stimulation of tumor cells such as induction of inflammation. Finally, we will describe the potential therapeutic strategies of bacteria on target tumors to improve treatment while mitigating adverse reactions. Cancer is a series of genetic changes that transform normal cells into tumor cells. These changes come from several reasons, including smoking, drinking alcohol, sunlight, exposure to chemical or physical factors, and finally chronic infection with microorganisms, including bacteria. In fact, bacterial infections are not carcinogenic, but recently it was discovered that the association between bacteria and cancer is through two mechanisms, the first stimulating chronic inflammation and the second producing carcinogenic metabolites. While bacteria are carcinogenic agents also, they have a dual role eliminating and removing tumor cells. However, the traditional cancer treatments that include chemotherapy, radiotherapy, surgery, and immunotherapy increase the chances of survival, and there are many side effects of these therapies, including the high toxicity of tissues and normal cells, could not penetrate the tumor cells, and resistance of these therapies by tumor cells. Therefore, the world has turned to an alternative solution, which is the use of genetically engineered microorganisms; thus, the use of living bacteria targeting cancerous cells is the unique option to overcome these challenges. Bacterial therapies, whether used alone or combination with chemotherapy, give a positive effect to treat multiple conditions of cancer. Also, bacteria can be used as vectors for drug, gene, or therapy, and this is a great step to treat cancer. Thus, we review the mechanisms underlying the interaction of the microbiota residents with cancer. Cancer-associated bacteria differ from those in healthy human and are linked with gene-expression profile. We also discuss how live bacteria interact with tumor microenvironments to induce tumor regression through colonization and spread. Finally, we provide past and ongoing clinical trials that include bacteria targeting tumors.

Environmental water is an important source for Vibrio cholerae, which is autochthonous to the aquatic environment, monitoring this bacterium in water is important for control of cholera. Vibrio cholerae represents an enormous public health problem around the world, especially in developing countries. One hundred samples were collected and selected. All presumptive isolates were con irmed by using a series of biochemical tests including Oxidase test, Simmon Citrate test, DNase test, Indole test, Klingler Iron Agar (KIA) test, Mac-Conkey agar test and motility. Con irmed Vibrio cholera strains were then screening for slide agglutination test by using commercially antisera polyvalent and monovalent O1 and O139 for determining strain serotype. The resistance to antibiotics by Vibrio cholerae was determining by using thirteen standardized disc diffusion including Amikacin, Ceftriaxone, Ceftazidime, Gentamycin, Tetracycline, Streptomycin, Tobramycin, Cephotaxime, Nalidixic Acid, Nor loxacin, Cephalothin, Rifampicin, Ce ixime. From one hundred water samples were detected, ifty-six samples were motile and positive for biochemical tests. Fifteen isolates con irmed as Vibrio cholera by Polymerase Chain Reaction (PCR) assay with primers designed for ctxA and 241bp band was observed. They showed sensitive to all antibiotics except Amikacin, Streptomycin, Ce ixime, Nor loxacin, Cephalothin. the aim of this study was determined the accurate method for detection of Vibrio cholerae in environmental water. In the current study, we found that the molecular method using Polymerase Chain Reaction performance using the ctxA gene-speci ic primers for detection of Vibrio cholerae was faster and accurate and speci ic.

Various of Streptomyces species have two kinds of plasmids, circular plasmids (8 to 31 kb) and linear plasmids (12 to 1700 kb). Covalently closed circular (CCC) plasmids are profuse in the genus of Streptomyces and involved in production and resistance of antibiotics by genetic controlling. We collected fifty clinical soil samples from different regions in Al-Najaf Al-Ashraf province/Iraq. The samples included five from Al-Ghadeer Quarter, five from Al-Karama Quarter, 10 from Kufa University, five from Al-Ameer Quarter, four from Al-Forat Quarter, 10 from North Quarters and eleven from desert roads in Al-Najaf. Diluted samples were cultured on Yeast extract Malt extract (YEME) agar medium as a selective medium; then the presumptive Streptomyces colonies were subcultured on Tryptone Yeast extract (TYE) agar, then incubation at 37ᵒC for 7 days. Seven biochemical tests for identification of Streptomyces isolates these are: Catalase test, Oxidase test, Urase test, Kligler Iron Agar test (KIA), Simmon᾽s Citrate test, addition to MacConkey agar test and Mannitol Salt agar test. Five antibiotic discs were used for detection of antibiotic sensitivity of the Streptomyces isolates; these are: Tetracycline, Gentamycin, Vancomycin, Ampicillin, Erythromycin. The sensitivity of the antibiotics was observed by recorded the diameter of inhibition zone around the discs. Two test bacteria (Staphylococcus aureus and E. coli) were used for the determination of antibacterial activity. Plasmid isolation was done by the alkaline lysis method. This method is characterized by the rapid isolation of DNA from Streptomyces. Then, detection of Plasmid DNA occurred by using agarose gel electrophoresis.