Evaluation of Hematological Profiles and Monocyte Subpopulations in Water Buffalo Calves after Immunization with Two Different IBR Marker Vaccines and Subsequent Infection with Bubaline alphaherpesvirus-1.

Bubaline alphaherpesvirus-1 (BuAHV-1) and Bovine alphaherpesvirus-1 (BoAHV-1) are respiratory viruses that can cause an infection known as "Infectious Bovine Rhinotracheitis" (IBR) in both water buffalo and bovine species. As the main disease control strategy, vaccination can protect animals from clinical disease through the development of specific humoral and cell-mediated immune responses. In the present study, the time-related circulatory kinetics of hematological profile and bubaline monocyte subsets have been investigated in vaccinated buffalo calves after challenge infections with BuAHV-1. Thirteen buffalo calves were selected and grouped into the VAX-1 group, which received an IBR-live-attenuated gE-/tk-deleted marker vaccine; the VAX-2 group, which received an IBR-inactivated gE-deleted marker vaccine; the CNT group, which remained an unvaccinated control. Fifty-five days after the first vaccination, the animals were infected with 5 × 105.00 TCID50/mL of wild-type BuAHV-1 strain via the intranasal route. Whole blood samples were collected at 0, 2, 4, 7, 10, 15, 30, and 63 days post-challenge (PCDs) for the analysis of hematological profiles and the enumeration of monocyte subsets via flow cytometry. The analysis of leukocyte compositions revealed that neutrophils were the main leukocyte population, with a relative increase during the acute infection. On the other hand, a general decrease in the proportion of lymphocytes was observed early in the post-infection, both for the VAX-1 and VAX-2 groups, while in the CNT group, the decrease was observed later at +30 and +63 PCDs. An overall infection-induced increase in blood total monocytes was observed in all groups. The rise was especially marked in the animals vaccinated with an IBR-live-attenuated gE-/tK-deleted marker vaccine (VAX-1 group). A multicolor flow cytometry panel was used to identify the bubaline monocyte subpopulations (classical = cM; intermediate = intM; and non-classical = ncM) and to investigate their variations during BuAHV-1 infection. Our results showed an early increase in cMs followed by a second wave of intMs. This increase was observed mainly after stimulation with live-attenuated viruses in the VAX-1 group compared with the animals vaccinated with the inactivated vaccine or the non-vaccinated animal group. In summary, the present study characterized, for the first time, the hematological profile and distribution of blood monocyte subsets in vaccinated and non-vaccinated water buffalo in response to experimental infection with BuAHV-1. Although not experimentally proven, our results support the hypothesis of a linear developmental relationship between monocyte subsets.

In-depth immunophenotyping reveals significant alteration of lymphocytes in buffalo with brucellosis.

Water buffalo (Bubalus bubalis) has a prominent position in the livestock industry worldwide but still suffers from limited knowledge on the mechanisms regulating the immune against infections, including brucellosis (BRC), one of the most significant neglected zoonotic diseases of livestock. Seventy-three buffalo were recruited for the study. Thirty-five were naturally infected with Brucella spp. The aims of the study were to (i) verify the cross-reactivity of 16 monoclonal antibodies (mAbs) developed against human, bovine, and ovine antigens; (ii) evaluate lymphocyte subset alterations in BRC positive buffalo; (iii) evaluate the use of the canonical discriminant analysis (CDA), with flow cytometric data, to discriminate BRC positive from negative animals. A new set of eight mAbs (anti CD3e, CD16, CD18, CD45R0, CD79a; CD172a) were shown to cross-react with water buffalo orthologous molecules. BRC positive animals presented a significant (p < 0.0001) decrease in the percentage of PBMC (29.5 vs. 40.3), total, T and B lymphocytes (23.0 vs. 35.5, 19.2 vs. 28.9, 2.6 vs. 5.7, respectively). In contrast, they showed an increase in percentage of granulocytes (65.2 vs. 55.1; p < 0.0001) and B lymphocytes CD21neg (22.9 vs. 16.1; p = 0.0067), a higher T/B lymphocyte ratio (10.3 vs. 6.4; p = 0.0011) and CD3+ /CD21+ (14.7 vs. 8.3; p = 0.0005) ratio. The CDA, applied to 33 different flow cytometric traits, allowed the discrimination of all BRC positive from negative buffalo. Although this is a preliminary study, our results show that flow cytometry can be used in a wide range of applications in livestock diseases, including in support of uncertain BRC diagnoses.

Detection of Bovine viral diarrhea virus from three water buffalo fetuses (Bubalus bubalis) in southern Italy.

Bovine viral diarrhea virus (BVDV) is an important pathogen that primarily infects ruminants, leading to several clinical problems including abortion. BVDV-specific antibodies were reported in a wide range of hosts within domestic and wildlife animal populations, and serological studies also indicated BVDV infection in buffaloes. The purpose of this study was to analyze the presence of BVDV in 2 water buffalo (Bubalus bubalis) herds with a history of abortion. Virus isolation from aborted fetuses and from maternal buffy coat and the molecular characterization of the isolates confirmed the presence of BVDV in these animals. The sequence analysis based on the 5' UTR and N(pro) coding regions of the Pestivirus genome revealed that the isolates belong to subgenotype 1b of BVDV. The findings of this study also suggest a possible role of BVDV in causing congenital infection in water buffalo. Its presence in fetal tissues as well as in maternal blood raises questions about the possible development of clinical disease or its influence in abortions in water buffalo.