New and natural antimicrobials as an alternative control system are now an urgent need to overcome stubborn bacterial infections. Salmonella Typhimurium has become the most frequent serovar responsible for salmonellosis in humans around the world. The high antimicrobial resistance and biofilm production make this pathogen more dangerous. We aimed to isolate a broad lytic phage to prevent Salmonella infection and reduce its biofilms. Using Salmonella Typhimurium (ST-4) as a host, seven phages were isolated, and only three phages showed clear lytic plaques, two members of the Siphoviridae family (vB_STS-1 and vB_STS-3) and one of the Myoviridae family (vB_STM-2). The vB_STM-2 phage was the most potent broad lytic phage, infecting 100% of tested Salmonella Typhimurium serovars and non-Salmonella strains. Additionally, the vB_STM-2 phage was thermostable at −20 to 55 °C up to 24 h, while at 65 and 75 °C, a significant (p < 0.05) titer reduction was observed after 7 days. Moreover, the phage seemed to be stable at different pHs (4–11) after one to twelve hours (hrs), while increasing the time made the phage more sensitive to the alkaline medium rather than the acidic medium. Interestingly, the vB_STM-2 phage had the capacity to diminish or eradicate the biofilms of tested Salmonella Typhimurium, e.g., ST-4, ST-19, ST-30, ST-37, ST-45 and ST-49 by 81.2%, 76.4%, 43.6%, 41%, 39.8% and 93.4%, respectively, at a titer concentration of 106 PFU/mL. Eventually, the vB_STM-2 phage showed significant (p < 0.05) efficacy in the elimination of Salmonella Typhimurium (ST-4) from contaminated chicken breasts at both storage periods with high titer stability. The Salmonella count showed a severe decline from 7.00 ± 0.63 log10 CFU/cm2 to 0.88 ± 0.17 log10 CFU/cm2 on the seventh day of the short-term storage, and from 5.13 ± 0.44 log10 CFU/cm2 to 1.10 ± 0.12 log10 CFU/cm2 on day 27 of the long-term assay. In both periods, the phage titers remained stable, with insignificant (p < 0.05) loss. Therefore, this phage is considered a prime candidate to combat multi-drug-resistant Salmonella Typhimurium and its biofilms.

Cucumber production exposed to huge losses in Egypt and worldwide due to infection with Cucumber mosaic Cucumovirus (CMV). The current study focus on the impact of two Egyptian CMV isolates on metabolic and oxidative activities in cucumber plants. Two CMV isolates was obtained from cucurbitaceous crops and confirmed by DAS-ELISA. Inoculated cucumber plants by infectious crude sap with two CMV isolates showed difference in external symptoms. The metabolic and biochemical components of cucumber plants were affected with two CMV isolates. The present study provided that, CMV infection caused a significant reduction in both photopigments and biochemical components while bioactive components (proline and phenol) and oxidative enzymes (POX, SOD, PPO and CAT) were increased significantly compared healthy ones. It was found that cucumber-CMV isolate was more effective in metabolic and biochemical than Squash-CMV isolate.

Detection of the hepatitis C virus (HCV) genome is crucial for diagnosis of HCV infection and for monitoring the efficacy of HCV treatment. Thus, we aimed to develop a convenient screening test for common HCV genotypes based on melting curve analysis with PCR. Serum samples were drawn from 124 patients with known HCV infection confirmed to be antibody and HCV RNA positive. A characteristic melting curve was obtained by monitoring the fluorescence as the temperature increased through the melting point of the PCR product. Results were compared with those obtained by the restriction fragment length polymorphism (RFLP) genotyping method. The melting curve analysis indicated that the different genotypes had discrete melting points (P < 0.0001): 90.43 +/- 0.065 degrees for genotype 1 (n = 35), 90.21 +/- 0.064 degrees for genotype 2 (n = 18), 90.62 +/- 0.045 degrees for genotype 3 (n = 29) and 90.84 +/- 0.130 degrees for genotype 4 (n = 42). The genotype was determined for all samples using the newly developed method as well as RFLP, and the two systems produced concordant results. The sensitivity of the assay was 91.4 % for genotype 1, 83.3 % for genotype 2, 93.1 % for genotype 3, and 85.7 % for genotype 4. Genotypes detected by melting curve analysis significantly correlated with those detected by RFLP (r = 0.946, P < 0.0001) with a strong linear relationship (r = 0.895). This melting curve analysis is a rapid, convenient and low-cost screening test for differentiation of HCV genotypes 1-4.