Identification of strain diversity and phylogenetic analysis based on two major essential proteins of Orf viruses isolated from several clinical cases reported in Malaysia

Abstract

There is a little information on the characterization of Orf virus strains that are endemic in Malaysia. The relationship between the severity of disease and the molecular genetic profile of Orf virus strains has not been fully elucidated. This study documented the first confirmed report of contagious ecthyma causing by Orf virus in goats from a selected state of eastern peninsular Malaysia. The disease causes significant debilitation due to the inability of affected animals to suckle which brings a great economic loss to the farmers. A total of 504 animals were examined individually to recognize the affected animals with Orf lesion. Skin scrapping was used to collect the scab material from the infected animals. The presence of Orf virus was confirmed by combination of methods including virus isolation on vero cells, identification by Transmission Electron Microscopy (TEM) and molecular technique using PCR and Sanger sequencing. The results showed the successful isolation of four Orf virus strains with a typical cytopathic effects on the cultured vero cells line. The morphology was confirmed to be Orf virus with a distinctive ovoid and criss cross structure. The phylogenetic analysis revealed that these isolated strains were closely related to each other and to other previously isolated Malaysian orf viruses. In addition these Orf virus strains were closely related to Orf viruses from China and India. This study provides more valuable insight in terms of genotype of Orf virus circulating in Malaysia.

Molecular Characterization and Phylogenetic Analysis of Orf Virus Isolated From Goats in Sokoto metropolis, Nigeria

“…Contagious ecthyma (CE) is a highly contagious viral disease of small ruminants such as sheep and goats [1] that occasionally affects camels [2] and wild ruminants with huge economic impact on the livestock industry [2][3][4][5][6]. Clinically, the disease is associated with skin lesions such as erythema, macules, papules, vesicles, pustules and crusts on the lips, tongue, teat, nose, hooves and other parts of the body [6] especially in young lambs and kids [3,7]. The disease is generally selflimiting, however, secondary bacterial infection may complicate the situation, causing inappetence, severe emaciation and death of the affected animals [1].…”

“…Nowadays, confirmation of CE is achieved using polymerase chain reaction (PCR) which has been shown to be highly specific and sensitive [ 1 , 13 , 16 , 19 ]. Using PCR, sequencing and phylogenetic analysis, genetic characteristic and diversity of orf virus has been described in many countries around the world including China [ 5 , 19 , 20 ], Taiwan [ 13 ], Malaysia [ 7 ], India [ 12 ], Uruguay [ 3 ] and a few African countries such as Tanzania [ 21 ], Ethiopia [ 17 , 22 ], Egypt [ 23 , 24 ], Gabon [ 25 ] and Sudan [ 26 , 27 ]. To date, outbreaks of CE in Nigeria are largely reported based on clinical manifestation of the disease and PCR to confirm cases [ 1 , 2 , 4 ] but no literature on the molecular characterization of the circulating orf virus isolates is currently available in Nigeria as at the time of this study.…”

Contagious ecthyma: how serious is the disease worldwide?

“…There were cases of CE lesion development associated with erythema multiform and bullous pemphigoid-like eruption and large vesiculo-pustular structures (Alian et al, 2015). The human form of CE is more persistent in livestock-rearing communities and meat processors (Buchan, 1996;Jesse et al, 2018b;Bala et al, 2020). The inter-human transmission of CE is rare.…”

Molecular Characterization and Phylogenetic Analysis of Orf Virus Isolated From Goats in Sokoto Metropolis, Nigeria

“…Contagious ecthyma (CE) is a highly contagious viral disease of small ruminants such as sheep and goats (1) that occasionally affects camels (2) and wild ruminants with huge economic impact on the livestock industry (2)(3)(4)(5)(6). Clinically, the disease is associated with skin lesions such as erythema, macules, papules, vesicles, pustules and crusts on the lips, tongue, teat, nose, hooves and other parts of the body (6) especially in young lambs and kids (3,7). The disease is generally self-limiting, however, secondary bacterial infection may complicate the situation, causing in-appetence, severe emaciation and death of the affected animals (1).…”

“…CE is achieved using polymerase chain reaction (PCR) which has been shown to be highly specific and sensitive (1,13,16,19). Using PCR, sequencing and phylogenetic analysis, genetic characteristic and diversity of ORFV has been described in many countries around the world including China (5,19,20), Taiwan 13, Malaysia (7), India (12), Uruguay (3) and few African countries such as Tanzania (21), Ethiopia (17,22), Egypt (23,24), Gabon (25) and…”