Article history: Received: 24-07-2017, Accepted: 25-10-2017, Published online: 30-11-2017
Corresponding author: Rajendra Singh
E-mail: email@example.comCitation: Singh R, Kumar P, Singh R, Dhama K, Kumari S, Yadav JP, Kashyap G, Singh KP, Singh V, Sahoo M (2017) Pathology and polymerase chain reaction detection of ovine progressive pneumonia (maedi) cases in slaughtered sheep in India, Veterinary World, 10(11): 1401-1406.
Aim: The small ruminant lentiviruses are known to cause maedi-visna (MV) and caprine arthritis - encephalitis in sheep and goats, typically affecting joints, udder, lungs, and the central nervous system. The diagnosis usually involves serology, clinical signs, immunohistochemistry, and polymerase chain reaction (PCR). In the present study, the histopathologically positive pneumonia cases of MV were confirmed by PCR in lung tissue probably for the first time in India.
Materials and Methods: A total of 888 lungs of adult sheep, aged between 2 and 5 years, were screened during slaughter, of which 121 were found to have pneumonic lesions. The tissues from each pneumonic lung including associated lymph nodes were collected in 10% neutral buffered formalin for histopathology. The frozen tissues of the same were also collected and stored at -20°C for PCR confirmation.
Results: Three of 121 cases of pneumonic lungs of sheep revealed gross and histopathological lesions suggestive of maedi or ovine progressive pneumonia infection. These 3 cases were further confirmed by PCR technique that amplified 291-base pair DNA in the long terminal repeat sequence of MV provirus.
Conclusion: This study suggests the low occurrence of MV virus (MVV) infection in India in naturally affected sheep based on pathomorphological lesions and using the molecular tool of PCR detection of the virus in tissues. Further, a combination of pathomorphology or/and PCR testing might be optimal for detecting the animals infected with MVV.
Keywords: histopathology, maedi-visna, ovine progressive pneumonia, polymerase chain reaction, small ruminant lentiviruses.
1. Minardi, C.J.C., Singh, D.K., Lamara, A. and Chebloune, Y. (2013) Small ruminant Lentiviruses (SRLVs) break the species barrier to acquire new host range. Viruses, 5: 1867-1884. [Crossref] [PubMed] [PMC]
2. Sanjose, L., Crespo, H., Blatti-Cardinaux, L., Glaria, I., Martinez-Carrasco, C., Berriatua, E., Amorena, B., Andres, D., Bertoni, G. and Reina, R. (2016) Post-entry blockade of small ruminant Lentiviruses by wild ruminants. Vet. Res., 1: 1-12. [Crossref]
4. Hananeh, W. and Barhoom, S. (2009) Outbreak of maedi-visna in sheep and goats in Palestine. Appl. Sci. J., 7: 19-23.
5. Minguijon, E., Reina, R., Perez, M., Polledo, L., Villoria, M., Ramirez, H., Leginagoikoa, I., Badiola, J.J., Garcia-Marin, J.F., de Andres, D. and Lujan, L. (2015) Small ruminant Lentivirus infections and diseases. Vet. Microbiol., 181: 75-89. [Crossref] [PubMed]
6. Ramirez, H., Reina, R., Amorena, B., Andres, D.D. and Martinez, H.A. (2013) Small ruminant Lentiviruses: Genetic variability, tropism and diagnosis. Viruses, 5: 1175-1207. [Crossref] [PubMed] [PMC]
8. Herrmann-Hoesing, L.M., White, S.N., Lewis, G.S., Mousel, M.R. and Knowles, D.P. (2007) Development and validation of an ovine progressive pneumonia virus quantitative PCR. Clin. Vac. Immunol., 14: 1274-1278. [Crossref] [PubMed] [PMC]
9. Martin, W.B. and Aitken, I.D. (2002) Diseases of Sheep. 3rd ed. Blackwell Science, Oxford. p187-191. [PMC]
10. Peterhans, E., Greenland, T., Badiola, J., Harkiss, G., Bertoni, G., Amorena, B., Eliaszewicz, M., Juste, R.A., Krassnig, R., Lafont, J.P., Lenihan, P., Petursson, G., Pritchard, G., Thorley, J., Vitu, C., Mornex, J.F. and Pepin, M. (2004) Routes of transmission and consequences of small ruminant Lentiviruses (SRLVs) infection and eradication schemes. Vet. Res., 35: 257-274. [Crossref] [PubMed]
11. Christodoulopoulos, G. (2006) Maedi-visna: Clinical review and short reference on the disease status in Mediterranean countries. Small Ruminant Res., 62: 47-53. [Crossref]
12. Leroux, C., Cruz, J.C.M. and Mornex, J.F. (2010) SRLVs: A genetic continuum of lentiviral species in sheep and goats with cumulative evidence of cross species transmission. Curr. HIV Res., 98: 94-100.
13. De Andres, D., Klein, D., Watt, N.J., Berriatua, E., Torsteinsdottir, S., Blacklaws, B.A. and Harkiss, G.D. (2005) Diagnostic tests for small ruminant Lentiviruses. Vet. Microbiol., 107: 49-62. [Crossref] [PubMed]
14. Georgsson, G. and Palsson, P.A. (1971) The histopathology of maedi, a slow viral pneumonia of sheep. Vet. Pathol., 8: 63-80. [Crossref]
15. Lopez, C.M., Lago, N., Vi-a, M., Panadero, R., Diaz, P., Diez-Ba-os, P., Morrondo, P. and Fernandez, G. (2013) Lungworm infection and ovine visna-maedi: Real risk factor or a confounding variable? Small Ruminant Res., 111: 157-161. [Crossref]
16. Watt, N.J., King, T.J., Collie, D., McIntyre, N., Sargan, D. and McConnell, I. (1992) Clinic pathological investigation of primary, uncomplicated maedi-visna virus infection. Vet. Rec., 131: 455-461. [Crossref] [PubMed]
17. Lopez, A. (2007) Respiratory system. In: McGavin, M.D. and Zachary, J.F., editors. Pathologic Basis of Veterinary Disease. 4th ed. Mosby, St. Louis, MO. p531-532.
18. Extramiana, A.B., Gonz'alez, L., Cortabarr'ia, N., Garc'ia, M. and Juste, R.A. (2002) Evaluation of a PCR technique for the detection of maedi-visna proviral DNA in blood, milk and tissue samples of naturally infected sheep. Small Ruminant Res., 44: 109-118. [Crossref]
19. Preziuso, S., Taccini, E., Rossi, G., Renzoni, G. and Braca, G. (2003) Experimental maedi-visna virus infection in sheep: A morphological, immunohistochemical and PCR study after three years of infection. Eur. J. Histochem., 47: 373-378. [PubMed]
20. Bancroft, J.D. and Gamble, M. (2008) Theory and Practice of Histological Techniques. Elsevier Health Sciences, United Kingdom. p5-9.
21. Benavides, J., Garcia-Pariente, C., Gelmetti, D., Fuertes, M., Ferreras, M.C., Garcia-Marin, J.F. and Perez, V. (2006) Effects of fixative type and fixation time on the detection of maedi-visna virus by PCR and immunohistochemistry in paraffin-embedded ovine lung samples. J. Virol. Methods., 137: 317-324. [Crossref]
23. Sasani, F., Javanbakht, J., Hemmatzadeh, F., Moghadam, M.R. and Hassan, M.A.M. (2013) Evaluation of histopathological on maedi disease with serological confirmation in North-East of Iran. Res. J. Infect. Dis., 1: 1-5. [Crossref]
24. Villagra-Blanco, R., Dolz, G., Solorzano-Morales, A., Alfaro, A., Montero-Caballero, D. and Romero-Zu-iga, J.J. (2015) Presence of maedi-visna in Costa Rican sheep flocks. Small Rum. Res., 124: 132-136. [Crossref]
25. Knowles, Jr D.P. (1997) Laboratory diagnostic tests for retrovirus infections of small ruminants. Vet. Clin. North. Am. Food Anim. Pract., 13: 1-11. [Crossref]
26. Alvarez, V., Arranz, J., Daltabuit-Test, M., Leginagoikoa, I., Juste, R.A., Amorena, B., de Andres, D., Lujan, L.L., Badiola, J.J. and Berriatua, E. (2005) Relative contribution of colostrum from maedi-visna virus (MVV) infected ewes to MVV-seroprevalence in lambs. Res. Vet. Sci., 78: 237-243. [Crossref] [PubMed]
28. Jubb, K.V.F., Kennedy, P.C. and Palmer, N. (1993) Pathology of Domestic Animals. 4th ed., Vol. 3. Academic, New York. p653.
29. Azizi, S., Tajbakhsh, E., Fathi, F., Oryan, A., Momtaz, H. and Goodarzi, M. (2012) Maedi in slaughtered sheep: A pathology and polymerase chain reaction study in southwestern Iran. Trop. Anim. Health Prod., 44: 113-118. [Crossref] [PubMed]
30. Brinkhof, J.M.A., Houwers, D.J., Moll, L., Dercksen, D. and Van Maanen, C., (2010) Diagnostic performance of ELISA and PCR in identifying SRLV-infected sheep and goats using serum, plasma and milk samples and in early detection of infection in dairy flocks through bulk milk testing. Vet. Microbiol., 142: 193-198. [Crossref]
31. Barquero, N., Domenech, A., Arjona, A., Fernandez-Garayzabal, J.F., Ruiz-Santa-Quiteria, J.A. and Gomez-Lucia, E. (2013) Comparison of two PCR and one ELISA techniques for the detection of small ruminant Lentiviruses (SRLVs) in milk of sheep and goats. Res. Vet. Sci., 94: 817-819. [Crossref]
32. Glaria, I., Reina, R., Ramirez, H., De Andres, X., Crespo, H., Jauregui, P., Salazar, E., Lujan, L., Perez, M.M., Benavides, J. and Perez, V. (2012) Visna/maedi virus genetic characterization and serological diagnosis of infection in sheep from a neurological outbreak. Vet. Microbial., 155: 137-146. [Crossref] [PubMed]
33. Zanoni, R.G., Nauta, I.M., Kuhnert, P., Pauli, U., Pohl, B. and Peterhans, E. (1992) Genomic heterogeneity of SRLV detected by PCR. Vet. Microbiol., 33: 341-351. [Crossref]
35. Rajya, B.S. and Singh, C.M. (1964) The pathology of pneumonia and associated respiratory disease of sheep and goats. Occurrence of jagziekte and maedi in sheep and goats in India. Am. J. Vet. Res., 25: 61-7. [PubMed]
36. Sharma, D.N., Rajya, B.S. and Dwivedi, J.N. (1976) Patho-anatomical studies of meningoleuco-encephalitis in maedi of sheep and goats. Indian. J. Anim. Sci., 44: 480-484.37. Ramesh, K.P. (2005) Studies on pathology of ovine pneumonia and experimental Pastueurella multocida infection in rabbits. Indian. J. Vet. Pathol., 29: 153.