The participation of a malignant catarrhal fever virus and Mycoplasma bovis in the development of single and mixed infections in beef and dairy cattle with bovine respiratory disease

Authors: OLIVEIRA, THALITA - State University Of Londrina; SCUISATO, GABRIELA - State University Of Londrina; PELAQUIM, ISADORA - State University Of Londrina; Cunha, Cristina; CUNHA, LUCAS - State University Of Londrina; FLORES, EDUARDO - Universidade Federal De Santa Maria; PRETTO-GIORDANO, LUCIENNE - State University Of Londrina; LISBOA, JULIO - State University Of Londrina; ALFIERI, AMAURI - State University Of Londrina; SAUT, JOAO - Universidade Federal De Minas Gerais; CUNHA, PAULO - Federal University Of Goias; HEADLEY, SELWYN - State University Of Londrina

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2021
Publication Date: 7/22/2021
Citation: Oliveira, T.E., Scuisato, G.S., Pelaquim, I.F., Cunha, C.W., Cunha, L.S., Flores, E.F., Pretto-Giordano, L.G., Lisboa, J.A., Alfieri, A.A., Saut, J.P., Cunha, P.H., Headley, S.A. 2021. The participation of a malignant catarrhal fever virus and Mycoplasma bovis in the development of single and mixed infections in beef and dairy cattle with bovine respiratory disease. Frontiers in Veterinary Science. 8. Article 691448. https://doi.org/10.3389/fvets.2021.691448.
DOI: https://doi.org/10.3389/fvets.2021.691448

Interpretive Summary: Bovine respiratory disease (BRD) is a complex multifactorial disease of cattle with significant impact in agriculture. BRD is caused by multiple viruses and/or bacteria and is frequently associated to unfavorable management practices and environmental conditions. In this study we evaluated the contribution of specific infectious disease agents in the development of BRD in cattle from Brazil. One hundred and twenty lung samples from cattle with BRD were evaluated using histology and immunohistochemistry. Presence of Mycoplama bovis and five viruses, bovine alphaherpesvirus 1 (BoHV-1), bovine parainfluenza virus 3 (BPIV-3), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), and malignant catarrhal fever viruses (MCFV), were investigated in lung lesions and their presence associated with different patterns of pneumonia. All pathogens were detected in one or more lung tissues. BVDV, MCFV and M. bovis were the most frequently agents found as singular or concomitant infections in cattle in Brazil. The results indicate that MCFV and M. bovis are associated with BRD and that their role in the disease development warrants further investigation.

Technical Abstract: The bovine respiratory disease (BRD) complex is a multietiological and multifactorial disease associated with a wide range of viral and bacterial pathogens. This study evaluated the contribution of specific infectious disease agents in the development of BRD in cattle from Brazil and determined if a virus within the malignant catarrhal fever virus (MCFV) group and Mycoplasma bovis, acting individually or in conjunction, can be associated with the development of BRD. Formalin-fixed paraffin-embedded pulmonary sections were used in immunohistochemical assays to determine the intralesional presence of six antigens associated with BRD: bovine alphaherpesvirus 1 (BoHV-1), bovine parainfluenza virus 3 (BPIV-3), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), MCFV, and M. bovis. Pneumonia was diagnosed in 82.7% (120/145) of all cattle evaluated. Interstitial pneumonia (60%, 72/120) and suppurative bronchopneumonia (25.8%, 31/120) were the most frequent patterns of pneumonia identified. Intralesional antigens of MCFV (53.3%, 64/120) were the most frequently associated with BRD, followed by M. bovis (47.5%, 57/120), BVDV (42.5%, 51/120), BoHV-1 (28.3%, 34/120), BRSV (24.2%, 29/120), and BPIV-3 (8.3%, 10/120). Additionally, antigens of BVDV, MCFV, and M. bovis were the most frequently identified agents associated with singular and concomitant infections. The MCFV identified during this study is more likely to be ovine gammaherpesvirus 2 (OvHV-2), since OvHV-2 is the only MCFV identified within the geographical region of this study. Interstitial pneumonia with proliferative vascular lesions may be a useful histologic feature to differentiate MCFV-induced pneumonia from other viral pneumonias of cattle. These results demonstrate that MCFV and M. bovis, in single or mixed infections, can produce pneumonia in cattle and should therefore be considered as primary agents in the development of BRD.