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.

A decade of tuberculosis eradication programs in the Mediterranean water buffalo (Bubalus bubalis) in South Italy: Are we heading toward eradication?

The water buffalo (Bubalus bubalis) is susceptible to bovine tuberculosis (TB), which receives increased attention in areas where buffalo breeding is prevalent, such as in Southern Italy, especially in the Campania region, where 70% of the buffalo stock is bred. Since 2012, TB testing in buffalo herds has been conducted using the Single Intradermal Test (SIT), with the Comparative Intradermal test (CIT) used in cases of inconclusive results. From 2012 to 2016, the interferon-gamma (IFN-γ) test was occasionally employed experimentally in herds with TB outbreaks to expedite eradication efforts. A local TB eradication program was implemented in officially TB-free buffalo herds between 2017 and 2019. This program involves initial screening with SIT, followed by confirmatory tests, including CIT and IFN-γ, for positive reactions. Since June 2019, the IFN-γ test has replaced the CIT in officially TB-free herds upon positive SIT reactions. Additionally, in suspected and confirmed TB-outbreak herds, the IFN-γ test was used at the discretion of the competent authority. Between 2017 and 2019, approximately 295,000 buffaloes in Campania were screened annually with in vivo tests provided by TB eradication programs. During this period, 32,040 animals from 855 herds were tested using the IFN-γ test and 4,895 tested positive. Since 2020, the use of IFN-γ testing has increased, and has become a prerequisite for the acquisition of TB-free status and is being systematically applied for TB outbreak-extinction procedures. The test was performed in all breeding buffaloes in cases of doubtful SIT results in TB-free herds and when TB lesions are detected at slaughter in animals from TB-free herds. This combined approach helped detect more TB outbreaks, and thereby led to a reduction in the TB prevalence and incidence rates. By 2022, the prevalence had decreased to 1.56%, and the incidence had decreased to 0.73%, after the increased use of the IFN-γ test. This study highlights the effectiveness of implemented strategies in reducing TB in this region. Overall, the data demonstrate the successful impact of TB eradication measures and surveillance activities in reducing bubaline TB prevalence and incidence in the Campania region.

Assessment of Multicolor Flow Cytometry Panels to Study Leukocyte Subset Alterations in Water Buffalo (Bubalus bubalis) During BVDV Acute Infection.

The identification of cross-reactive monoclonal antibodies (mAbs) that recognize orthologous leukocyte differentiation molecules (LDM) in buffaloes has overcome a major impediment limiting research on the immune response to pathogens and development of vaccines. As reported, two pilot trials were conducted to accomplish two objectives: (1) demonstrate that multiparameter flow cytometry can be conducted equally well in buffalo with mAbs directly and indirectly labeled with fluorochromes in research and (2) flow cytometry can be used to compare and extend studies on diseases of economic importance to buffalo using bovine viral diarrhea virus (BVDV) as a model pathogen. Pregnant buffalo cows were infected with BVDV-1 at 81 (trial 1) and 203 (trial 2) days post artificial insemination and flow cytometric evaluations were performed at 0, 3, 4, and 14 days after infection (dpi). Fluorochrome conjugated mAbs were used in trial 1, and fluorochrome conjugated goat isotype specific anti-mouse antibodies were used to label mAbs in trial 2. Flow cytometric analysis revealed a transient lymphopenia occurs during the 1st days following infection similar to lymphopenia reported in cattle. In particular, significant differences were observed between pre- and post-infection absolute values of T lymphocytes (-56%, P < 0.01). CD21+ B lymphocytes (-65%, P = 0.04), and Natural Killer cells (-72%, P < 0.001). No significant differences were observed in monocytes and neutrophil absolute values, or the CD4:CD8 ratio. Animal health status was followed until 15 days after calving. No clinical signs of infection were observed during the evaluation period, however, animals in trial 1 developed complications later the infection. One cow aborted at 57 days post-infection, the second cow developed a prolapse a day after calving and died. These two animals also showed a more pronounced lymphopenia in comparison with animals infected at 203 days of pregnancy (e.g., -77 vs. -22% T lymphocytes at 3 dpi, respectively). The pilot studies have demonstrated that it is possible to use multicolour multiparameter flow cytometry to study the immune response to pathogens affecting the health of buffalo.

NIR multiphoton ablation of cancer cells, fluorescence quenching and cellular uptake of dansyl-glutathione-coated gold nanoparticles.

Theranostics based on two-photon excitation of therapeutics in the NIR region is an emerging and powerful tool in cancer therapy since this radiation deeply penetrates healthy biological tissues and produces selective cell death. Aggregates of gold nanoparticles coated with glutathione corona functionalized with the dansyl chromophore (a-DG-AuNPs) were synthesized and found efficient nanodevice for applications in photothermal therapy (PTT). Actually the nanoparticle aggregation enhances the quenching of radiative excitation and the consequent conversion into heat. The a-DG-AuNPs are readily internalized in Hep G2 where the chromophore acts as both antenna and transducer of the NIR radiation under two-photons excitation, determining efficient cell ablation via photothermal effect.