Infectious agents cause 15-20% of cancers worldwide. The contamination of infectious agents may be caused by a local chronic inflammatory response or tumorization. Mycoplasma contamination can interfere with biological agents and cause DNA damage which affects gene expression, disrupts the cell-cycle control and apoptotic responses. Mycoplasmas are widely distributed in nature; some mycoplasmas have the ability to penetrate into the cell and cause sever disease. Most mycoplasmas are known to infect the cell culture media, which is difficult to detect the contamination.M. hyorhinis is one of the main reasons the Mycoplasma contamination in tissues samples from cancer patients. Mycoplasma is related to human cancers and some other human diseases. Several studies have shown that M. hyorhinis potentially plays a role in esophageal, gastric, lung, breast, glioma, colon, and prostate cancers. The prevalence of M. hyorhinis in various tissues leads to cancer progression. Therefore, it is necessary to pay more attention to this mycoplasma agent in order to control and understand its mechanism.Article Info

Mycoplasma murisPCR New strain 16S rRNA sequences NIH MiceMycoplasma muris (M.M) is a small pathogenic bacterium that lives in the female mouse genital tract. Mycoplasma muris may have harmful effects on the reproductive health of female. This research was performed to optimize the detection of M. muris in NIH mice in the Department of Animal Breeding, Razi Vaccine and Research Institute, Iran. In this cross-sectional study, 29 vaginal samples of NIH mice were selected through simple random sampling. For detection of the mycoplasma, the vaginal tissue removal of samples was done. First, samples were crushed using mortar and pestle with PBS 1ml, then were cultured in the PPLO broth and incubated at 37°C for 24h, they were passed through 0.45 μm pore-size filters and inoculated into specific PPLO broth and agar media for 3-4 weeks. In the next section, the PCR test was used with primers of 16S rRNA gene of M. muris. From 29 tested samples, 17.24% samples were positive for M. muris by PCR method, while 35.93% cultures showed positive. The phylogenetic analysis indicated a new strain of M. muris. The results of culture and PCR methods displayed the contamination in NIH mice. Therefore, Therefore, more researches are needed regarding the presence of mycoplasma for treatment and clinical signs. Article Info

Introduction: Salmonella is a gram-negative intestinal microorganism that causes food poisoning in humans. The genus Salmonella has five virulence genes stn, Phop / Q, spvc, slyA and sopB. These genes encode proteins in different parts of the bacterium that can counteract the immune system, complement, and death within the cell. The aim of this study was to identify virulence genes in Salmonella typhimurium strains isolated from clinical specimens using Multiplex PCR and to determine their antibiotic resistance patterns. Materials and Methods: In this descriptive cross-sectional study, 60 stool specimens were collected from the patients with acute diarrhea and vomiting in Karaj hospitals and hospitals during 2017. Antibiotic susceptibility test was performed on Muller Hinton agar medium (CLSI). Multiplex PCR was also performed to detecting virulence genes using specific primers. Results: The results of antibiotic susceptibility test showed that all isolated samples were susceptible to imipenem, gentamicin and amikacin. Also, the frequency of Phop/Q, slyA and stn genes were 100%, 98.3% and 91.6%, respectively. Also, sopB and Spvc genes were not detected in Salmonella typhimurium isolates. Conclusion: The results of the present study indicate on the high incidence of virulence genes in Salmonella typhimurium clinical samples which can be considered as an alarm signal for the spread of these genes to other Salmonella serotypes.

Mycoplasma are small, cell-free bacteria enclosed by a membrane. These bacteria belong to the class of Mollicutes, the order of Mycoplasma tales, and the genus of Mycoplasma. There are more than 100 identified species of mycoplasma. The ratio of cytosine to guanine in its DNA is 23-40% and its genome size is 1350-600 kb. Mycoplasma require cholesterol to grow, and the temperature suitable for the growth of this bacteria is 37°C. Mycoplasma cause contamination and infections in humans and animals. Some mycoplasma species are seen only in animals. In general, mycoplasma are colonized at the surface of the mucus, and most species are noninvasive. Five main species of mycoplasma have been identified in laboratory mice, including: M.arthritidis, M.collis, M.muris, M.neurolyticum, and M.pulmonis. These species generally require protein-rich environments that contain 10-15% of the animal's serum, and their growth requires nicotinamide adenine nucleotide (NAD), which is commonly used to cultivate mycoplasma in mice. Laboratory research has found that mycoplasmas contamination has an adverse effect on animals. Therefore, it is important that health monitoring programs are implemented as a quality control for animals used in laboratory research.