Cattle experimentally infected by Anaplasma marginale : Influence of splenectomy on disease pathogenesis, oxidative profile, and antioxidant status

Evaluation of erythrocyte arginase activity, plasma nitric oxide concentration and oxidative stress status in cattle with anaplasmosis

Bovine anaplasmosis is an arthropod-borne disease characterized by high fever, anaemia and sometimes jaundice. The role of oxidative stress in anaplasmosis has been investigated, but erythrocyte arginase (ARG) activity has not been studied. In this study, we aimed to investigate the changes in haematological parameters, erythrocyte ARG activity, plasma nitric oxide (NO) levels and oxidative stress parameters and explain the relationship between each other in cattle with anaplasmosis. The material of this study consisted of 14 cattle, aged 10-12 months with anaplasmosis (infected group) and 14 healthy cattle aged 10-12 months (control group). Our data revealed that leukocyte parameters and plasma NO levels and serum malondialdehyde (MDA), total oxidant status (TOS) and oxidative stress index (OSI) levels were higher while erythrocyte parameters, erythrocyte ARG activity and serum total antioxidant status (TAS) and glutathione (GSH) levels were lower in the infected group compared to the control group. There was a strong correlation between erythrocyte ARG activity and NO, MDA, TOS, OSI, TAS and GSH. ROC analysis and correlation results suggest that erythrocyte ARG activity is an effective oxidative stress marker. We concluded that severe oxidative stress occurs in anaplasmosis. As the severity of anaemia increases, erythrocyte ARG activity plummets while plasma NO level elevates. These two parameters may also be used as prognostic and oxidative stress markers. Although decreased erythrocyte ARG activity is a disadvantage in haemolytic diseases, this situation can be compensated by increased NO. Thus, homeostasis of these two parameters may contribute to the elimination of the infection.

Naturally occurring Anaplasma marginale infection in cattle: Molecular prevalence and associated risk factors, haemato-biochemical alterations, oxidant/antioxidant status and serum trace mineral levels

The present investigation was undertaken to map the distribution of Anapalsma species infection in cattle from the Aizawl region of Mizoram, India, in relation to various risk factors, and to study the haemato-biochemical alterations, oxidant/antioxidant status and serum trace mineral levels in cattle with naturally occurring Anapalsma marginale infection. The study was carried out over 31 months from June 2019 to December 2021. A total of 401 cattle blood samples were collected and screened for the presence of Anaplasma spp. by microscopic examination and polymerase chain reaction (PCR). Non-infected clinically healthy cattle (n = 21) served as control. Blood samples were collected to study the haemogram and serum samples were used for the evaluation of biochemical parameters, oxidative stress indices and trace minerals. During the study period, an overall prevalence of 15.71% was recorded for A. marginale infection in cattle. The prevalence of A. marginale infection was highly associated with age, sex, breed and tick infestation status of animals, floor system and management of farms, and season. The mean values of total erythrocyte count (TEC), haemoglobin (Hb), packed cell volume (PCV), total platelet count, total protein, albumin, superoxide dismutase (SOD), glutathione (GSH), total antioxidant capacity (TAC), copper (Cu) and zinc (Zn) were significantly (P < 0.05) lower, whereas the mean values of mean corpuscular volume (MCV), aspartate aminotransferase (AST), total bilirubin, indirect bilirubin, blood urea nitrogen (BUN), creatinine and lipid hydroperoxide (LPO) were significantly (P < 0.05) higher in cattle infected with A. marginale. A negative correlation of TEC with LPO, and a positive correlation with SOD, GSH, TAC, Cu and Zn suggest a possible link between oxidative stress and the haemolytic crisis noticed in bovine anaplasmosis. Incorporation of antioxidants and organ protective drugs as an adjunct therapy may result in better prognosis.

Balanced Th1/Th2 immune response induced by MSP1a functional motif coupled to multiwalled carbon nanotubes as anti-anaplasmosis vaccine in murine model

Anaplasmosis is one of the most prevalent tick-borne diseases of cattle caused by Anaplasma marginale. MSP1a surface protein has been shown to be involved in eliciting immunity to infected cattle. Carbon nanotubes (CNTs) has been increasingly highlighted due to their needle like structure, which contain multiple attachment sites for biomolecules and may interact with or cross biological membranes, increasing antigen availability to immune system. Here, we have successfully designed a nanocomplex of a synthetic peptide noncovalently attached to multiwalled CNT (MWCNT). Peptide comprising the core motif of the MSP1a was efficiently adsorb onto the nanoparticle surface. The MWCNT-Am1 nanocomplex exhibited high stability and good dispersibility and in vivo immunization showed high levels of IgG1 and IgG2a, followed by increased expression of pro-inflammatory and anti-inflammatory cytokines. This is a proof-of-concept of a nanovaccine that was able to generate a strong immune response compared to the common antigen-adjuvant vaccine without the nanoparticles.