In the food and fertilizer industries, zinc oxide nanoparticles (ZnO-NPs) are frequently utilized. Our study conducted to assess the genotoxicity, biochemical alterations and histopathological parameters of ZnO NPs with a particle size of 30 ± 5 nm were orally administered to rats once daily at doses of 100, 200, 300, 400, and 600 mg/kg for ten week. The experiment involved the use of 30 Sprague–Dawley male rats exposed to various concentrations of ZnO-NPs. After the adaptation period, six groups were created out of the thirty rats (Five rats per group). Rats in Group 1 (G1), known as the control group, were fed a standard synthetic meal and had unlimited access to drinking water ad libitum, while those in the other five groups received oral gavage treatments with various doses of zinc oxide nanoparticles over a 10-week period. The results indicated that ZnO-NPs induces a lowering in body weight beginning in the sixth week while increasing serum AST, ALT, creatinine, and uric acid activity. However, the addition of different concentrations of ZnO NPs compared to the control caused insignificantly decreased on the plasma glucose level in all treated animals. Numerous chromosomal aberrations, including fragments, chromosome rings, chromatid breaks, end-to-end association, and centric fusion, were observed through cytogenetic investigation. When compared to the control group, hepatic vacuolation, large sinusoidal dilatation, degenerative alterations, and cellular congestion were observed in the liver of the male rats treated with 400 and 600 mg/kg of ZnO-NPs. According to the findings of in vivo genotoxicity experiments, rats' bone marrow cells, liver, and kidney can exhibit genotoxicity and cytotoxicity after exposed to ZnO NPs with particle sizes of 30 nm for ten weeks. The findings of this study could raise more concerns regarding the potential damage to human health associated with the widespread use of ZnO NPs.

Pasteurella multocida is the main cause of several infections of farm animals, and the immunity gained from commercial vaccines is for the short term only and needs to be routinely administered, so work on new vaccines against virulent P. multocida is crucial. In this study, the OmpH gene was amplified from ten P. multocida strains, and the PCR products were sequenced and analyzed. The results of RFLP analysis of OmpH gene digested by MspI enzyme showed that all of ten strains examined possessed one restriction site and two fragments, 350 and 650 bp. The OmpH sequence of strain No. 10 was cloned into bacterial expression vector pUCP24, and the recombinant pUCP24-OmpH was expressed in E. coli DH5α. Serum samples obtained from the ELISA test from a group of vaccinated rats indicate that the antibodies were present at high titer in immunized rats and can be tested as a vaccine candidate with a challenge. In rats infected with the DNA vaccine and inactivated vaccine, a significant increase in serum antibody levels was observed. In addition, the DNA vaccine provided the vaccinated rats with partial protection; however, the protective efficacy was greater than that offered by the live attenuated vaccine. This successful recombinant vaccine is immunogenic and may potentially be used as a vaccine in the future.