Bovine leukaemia virus (BLV) is a deltaretrovirus that is closely related to human T-cell leukaemia virus types 1 and 2 (HTLV-1 and -2). It causes enzootic bovine leukosis (EBL), which is the most important neoplastic disease in cattle. Most BLV-infected cattle are asymptomatic, which potentiates extremely high shedding rates of the virus in many cattle populations. Approximately 30% of them show persistent lymphocytosis that has various clinical outcomes; only a small proportion of animals (less than 5%) exhibit signs of EBL. BLV causes major economic losses in the cattle industry, especially in dairy farms. Direct costs are due to a decrease in animal productivity and in cow longevity; indirect costs are caused by restrictions that are placed on the import of animals and animal products from infected areas. Most European regions have implemented an efficient eradication programme, yet BLV prevalence remains high worldwide. Control of the disease is not feasible because there is no effective vaccine against it. Therefore, detection and early diagnosis of the disease are essential in order to diminish its spreading and the economic losses it causes. This review comprises an overview of bovine leukosis, which highlights the epidemiology of the disease, diagnostic tests that are used and effective control strategies.

(1) Background: Toxoplasma gondii (T. gondii) is one of the most prevalent parasites to affect humans and animals; (2) Methods: From January to December 2020, using a commercial enzyme-linked immunosorbent assay (ELISA) kit, a cross-sectional study was conducted to establish the seroprevalence of T. gondii in 390 dromedary camels raised in three governorates in Egypt and to identify the potential risk factors associated with infection; (3) Results: Overall, T. gondii seroprevalence in camels was 46.9%. Moreover, locality, sex, age, contact with small ruminants, history of abortion, and number of parities were found as risk factors for T. gondii infection in univariable analysis. The seropositivity to T. gondii increased significantly in camels living in Marsa Matrouh (OR = 2.02), among camels of more than 8 years old (OR = 5.28). Additionally, the likelihood of acquiring T. gondii infection was increased in camels that had contact with small ruminants (OR = 3.85) and a history of abortion (OR = 3.84) with these having parity more than four times (OR = 17.72); (4) Conclusions: The evaluation of seroprevalence and related risk factors for T. gondii infection is crucial for implementing an effective control programme to minimise and control T. gondii infection in camels and, as a result, transmission to humans.

Infectious bovine rhinotracheitis (IBR), caused by bovine alphaherpesvirus 1 (BoHV-1), is an important disease affecting cattle worldwide resulting in great economic losses. Marker vaccines are effective in controlling infectious diseases including IBR, because they allow the discrimination between the natural infection and the vaccination. Therefore, a triple gene deleted strain BoHV-1 gG-/tk-/gE- was developed and evaluated in vivo and in vitro as a marker vaccine. In cell culture, this triple mutant virus showed significantly slower growth kinetics and smaller plaques when compared to wild-type (wt) BoHV-1 and double mutant BoHV-1 gG-/tk- (p < 0.01). On proteomic level, it revealed downregulation of some virulence related proteins including thymidine kinase, glycoproteins G, E, I, and K when compared to the wt. In vitro, the triple mutant virus showed a significantly lower and shorter viral shedding period (p < 0.001) in calves compared to double mutant. Moreover, the immunized calves with triple mutant virus showed protection rates of 64.2% and 68.6% against wt BoHV-1 and wt BoHV-5 challenge, respectively, without reactivation of latency after dexamethasone injection. In conclusion, BoHV-1 gG-/tk-/gE- is a safer marker vaccine against IBR although its immunogenicity in calves was decreased when compared to double mutant virus.

(1) Background: Cystic echinococcosis is a zoonotic helminth disease that causes severe economic losses. The study aimed to assess the prevalence and viability of cystic echinococcosis in examined camels. In addition, assessing the histological, morphological, oxidative, and antioxidant state related to the cystic echinococcosis infection; (2) Methods: The study was performed on 152 slaughtered dromedary camels between March and September 2022 at El-Basatin abattoir in Cairo Governorate, Egypt; (3) Results: The results revealed that the prevalence of hydatidosis was 21.7% in slaughtered camel and the highest infection rate observed in lungs was 87.87%, while it was 9% in livers. Camels’ liver infections were rare, whereas their lung infections were more common. By comparing to non-infected camels, the level of MAD was significantly increased with hydatid cysts infection, while the level of GSH, SOD and CAT was significantly decreased. Histopathological section of camel cyst revealed layered membranes surrounded by a zone of cellular infiltration and an outermost fibrous tissue reaction. In addition, there was evidence of atelectasis, emphysema, hemorrhage, congestion, and fibrosis in the surrounding tissues. Nonetheless, the degeneration and necrosis of hepatocytes and other pathological alterations in liver cyst sections were remarkably comparable to those seen in the lungs. Furthermore, calcification was detected.

Mycoplasma bovis is a major pathogen, responsible for bovine respiratory diseases worldwide. The present lack of effective control measures leaves cattle owners at considerable perpetual risk of M. bovis outbreaks. In this study, we identified M. bovis secreted immunogenic proteins in silico as potential candidates for novel diagnostic agents and vaccines. We used immunoinformatics to analyze 438 M. bovis proteins previously identified with a label-free proteomics analysis of virulent M. bovis HB0801 (P1) and its attenuated P150 strains. The subcellular localization of these proteins was preliminarily screened and 59 proteins were found to be secreted extracellular proteins. Twenty-seven of these proteins contained a large number of predictive T-cell epitopes presented by major histocompatibility complex (MHC) class I and II molecules. Twenty-two of these 27 proteins had a high number of conformational B-cell epitopes, predicted from the corresponding 3D structural templates, including one unique to P1, two unique to P150, and 19 common to both strains. Five proteins were selected for further validation, and two of these, MbovP274 and MbovP570, were successfully expressed and purified. Both were confirmed to be secretory and highly immunogenic proteins that induced a mouse antibody response, reacted with cattle serum positive for M. bovis infection, and significantly increased the production of interleukin 8 (IL-8), IL-12 and interferon γ (IFN-γ) during the secretion of these three cytokines by both M. bovis mutants of these genes. These results should be useful in the development of novel immunological agents against M. bovis infection.

The immune and antioxidant genetic factors that could converse with mastitis susceptibility in dromedary camels were looked at in this research. Of 120 female dromedary camels (60 healthy, and 60 with mastitis) were utilised. Each camel’s jugular vein was pierced to obtain five millilitres of blood. The blood was placed within tubes containing sodium fluoride or EDTA anticoagulants to obtain whole blood and extract DNA and RNA. The immunological (OTUD3, TLR2, TLR4, STAB2, MBL2, TRAPPC9, and C4A) and antioxidant (CAT, SOD3, PRDX6, OXSR1, NDUFS6, SERP2, and ST1P1) genes’ nucleotide sequence polymorphisms between healthy and mastitis affected she-camels were discovered using PCR-DNA sequencing. Fisher’s exact test revealed that camel groups with and without mastitis had noticeably different odds of all major nucleotide alterations propagating (p < 0.01). Mastitic camels were significantly more likely to express the OTUD3, TLR2, TLR4, STAB2, MBL2, TRAPPC9, C4A, OXSR1, SERP2, and ST1P1 genes (p < 0.05). However, CAT, SOD3, PRDX6, and NDUFS6 genes elicited a different pattern. The results may be used to develop management strategies and support the significance of nucleotide differences and gene expression patterns in these markers as indicators of the incidence of mastitis.