A cross sectional study was conducted between January and May 2015 in and around Kombolcha town, Eastern Amhara, to identify methicillin resistant Staphylococcus aureus and their resistance to antimicrobials and also to identify risk factors associated with the occurrence of dairy cow mastitis. A total of 150 dairy cows were included during the study period. A total of 600 quarters were examined to detect clinical and subclinical mastitis by physical examinations of udder and milk and California mastitis test, respectively. The prevalence of mastitis was 56%. Age, milking hygiene, parity, and floor system had significant (p<0.05) effect on the prevalence of mastitis. S. aureus was isolated at a rate of 11 (73.3%) and 29 (42%) in clinical and subclinical mastitis, respectively. The result showed the occurrence of S. aureus in clinical mastitis was found to be significantly higher than subclinical mastitis (p=0.028). The present study showed that S. aureus was resistant to penicillin G (100%), amoxicillin (100%), cefoxitin (42.7%) and tetracycline (77.4%) however all the isolates were found to be totally (100%) susceptible to the gentamycin. 45.3% of the isolates were found to be multidrug resistant. Antimicrobial resistance is due to repeated therapeutic use of drugs. Regular antimicrobial sensitivity testing helps to select effective antibiotics that ultimately reduce the development of resistance towards commonly used antibiotics. In conclusion, Mastitis caused by S. aureus is one of the major problems of dairy cows in milk production in the study area.

The occurrence and severity of tumor, which is caused by many factors and etiological agents, become rapid and its distribution is worldwide that lead to death of many individuals. In order to avoid associated complications scientists discovered a means for the removal of tumor using oncolytic virus called virotherapy. This review is aiming to give highlight about the current advancements on the significance of oncolytic viruses in the treatment of tumor cells. Oncolytic viruses carry the promise to efficiently target cancer cells for destruction and spread throughout tumor tissue to reach distant loci without causing collateral damage to healthy tissues. Current oncolytic virotherapy strategies are based on the common molecular mechanisms of viral infection and cell transformation, like apoptotic dysregulation and cell cycle disruption. In this regards this time scientists is being done active research to improve the accessibility, safety and efficacy of oncolytic virotherapy.

Streptococcus species possesses a wide variety of virulence factors and can cause severe invasive infections. Accordingly, the field of bacterial pathogenesis has rapidly expanded with a greater understanding of pathogenesis at the molecular level over the last decades. The ability of bacteria to cause disease is described in terms of the number of infecting bacteria, the route of entry into the body, the effects of host defense mechanisms, and intrinsic characteristics of the bacteria called virulence factors. One essential prokaryotic cell function is the transport of proteins from the cytoplasm into other compartments of the cell, the environment, and/or other bacteria or eukaryotic cells a process known as protein secretion.Secreted proteins can play many roles in promoting bacterial virulence, from enhancing attachment to eukaryotic cells, to scavenging resources in an environmental niche, to directly intoxicating target cells and disrupting their functions. Virulence factors encoded on pathogenic islands represent the entire spectrum of bacterial virulence factors, from adhesins ,toxins, secretion systems, invasins, modulins, effectors, proteases, lipases, and enterotoxins, superantigens, iron uptake systems, immunoglobulin A proteases, capsule synthesis, host defense avoidance mechanisms.